1
|
Demers H. Contributions and Legacy of David C. Joy to Monte Carlo Simulations in Electron and Ion Microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:470-471. [PMID: 37613103 DOI: 10.1093/micmic/ozad067.221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
|
2
|
Orús P, Sigloch F, Sangiao S, De Teresa JM. Superconducting Materials and Devices Grown by Focused Ion and Electron Beam Induced Deposition. NANOMATERIALS 2022; 12:nano12081367. [PMID: 35458074 PMCID: PMC9029853 DOI: 10.3390/nano12081367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 01/27/2023]
Abstract
Since its discovery in 1911, superconductivity has represented an equally inciting and fascinating field of study in several areas of physics and materials science, ranging from its most fundamental theoretical understanding, to its practical application in different areas of engineering. The fabrication of superconducting materials can be downsized to the nanoscale by means of Focused Ion/Electron Beam Induced Deposition: nanopatterning techniques that make use of a focused beam of ions or electrons to decompose a gaseous precursor in a single step. Overcoming the need to use a resist, these approaches allow for targeted, highly-flexible nanopatterning of nanostructures with lateral resolution in the range of 10 nm to 30 nm. In this review, the fundamentals of these nanofabrication techniques are presented, followed by a literature revision on the published work that makes use of them to grow superconducting materials, the most remarkable of which are based on tungsten, niobium, molybdenum, carbon, and lead. Several examples of the application of these materials to functional devices are presented, related to the superconducting proximity effect, vortex dynamics, electric-field effect, and to the nanofabrication of Josephson junctions and nanoSQUIDs. Owing to the patterning flexibility they offer, both of these techniques represent a powerful and convenient approach towards both fundamental and applied research in superconductivity.
Collapse
Affiliation(s)
- Pablo Orús
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
| | - Fabian Sigloch
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
| | - Soraya Sangiao
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), University of Zaragoza, 50018 Zaragoza, Spain
| | - José María De Teresa
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), University of Zaragoza, 50018 Zaragoza, Spain
- Correspondence:
| |
Collapse
|
3
|
Audinot JN, Philipp P, De Castro O, Biesemeier A, Hoang QH, Wirtz T. Highest resolution chemical imaging based on secondary ion mass spectrometry performed on the helium ion microscope. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2021; 84:105901. [PMID: 34404033 DOI: 10.1088/1361-6633/ac1e32] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
This paper is a review on the combination between Helium Ion Microscopy (HIM) and Secondary Ion Mass Spectrometry (SIMS), which is a recently developed technique that is of particular relevance in the context of the quest for high-resolution high-sensitivity nano-analytical solutions. We start by giving an overview on the HIM-SIMS concept and the underlying fundamental principles of both HIM and SIMS. We then present and discuss instrumental aspects of the HIM and SIMS techniques, highlighting the advantage of the integrated HIM-SIMS instrument. We give an overview on the performance characteristics of the HIM-SIMS technique, which is capable of producing elemental SIMS maps with lateral resolution below 20 nm, approaching the physical resolution limits, while maintaining a sub-nanometric resolution in the secondary electron microscopy mode. In addition, we showcase different strategies and methods allowing to take profit of both capabilities of the HIM-SIMS instrument (high-resolution imaging using secondary electrons and mass filtered secondary sons) in a correlative approach. Since its development HIM-SIMS has been successfully applied to a large variety of scientific and technological topics. Here, we will present and summarise recent applications of nanoscale imaging in materials research, life sciences and geology.
Collapse
Affiliation(s)
- Jean-Nicolas Audinot
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, L-4422 Belvaux, Luxembourg
| | - Patrick Philipp
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, L-4422 Belvaux, Luxembourg
| | - Olivier De Castro
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, L-4422 Belvaux, Luxembourg
| | - Antje Biesemeier
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, L-4422 Belvaux, Luxembourg
| | - Quang Hung Hoang
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, L-4422 Belvaux, Luxembourg
| | - Tom Wirtz
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, L-4422 Belvaux, Luxembourg
| |
Collapse
|
4
|
Deng Y, Zhuang X, Wang W, Gu R, He D, Wang L, Cheng X. Direct visualization of beam-resist interaction volume for sub-nanometer helium ion beam-lithography. NANOTECHNOLOGY 2021; 32:415302. [PMID: 34198269 DOI: 10.1088/1361-6528/ac1099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Interaction volume of beam-resist is a basis unit of beam-lithography, directly determines the critical parameters of beam-lithography. We have visualized the interaction volume at the state-of-the-art sub-10 nm scale by a spot irradiation of sub-nanometer helium ion beam into an approximately free-standing resist. The visualized interaction volume suggests helium ion beam has an excellent capability in nanofabrication. Specifically, helium ion beam-lithography is 1000 times more efficient than electron beam-lithography (EBL), owns a sub-4 nm resolution, can achieve a large pattern aspect ratio (greater than 8), and does not suffer from backscattering effect at a normal exposure dose. Furthermore, the interaction volume has been theoretically studied by considering the spatial distribution of energy deposited in the resist, and eventually lead to a model for pattern prediction and proximity effect corrections. We expect that, our approach to visualize the interaction volume may be applied to study other high resolution lithographic techniques such as x-ray lithography and EBL, and it may open new possibilities in other applications, like beam-imaging, beam-milling, and beam-modification.
Collapse
Affiliation(s)
- Yunsheng Deng
- Pico Center and SUSTech Core Research Facilities, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
| | - Xin Zhuang
- Shenzhen Key Laboratory for Nanoimprint Technology, Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
- Department of Mechanical Engineering, the University of Hong Kong, Hong Kong
- HKU-Zhejiang Institute of Research and Innovation (HKU-ZIRI), Hangzhou, Zhejiang 311300, People's Republic of China
| | - Wu Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China
| | - Rui Gu
- Pico Center and SUSTech Core Research Facilities, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
| | - Dongsheng He
- Pico Center and SUSTech Core Research Facilities, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
| | - Liqiu Wang
- Department of Mechanical Engineering, the University of Hong Kong, Hong Kong
- HKU-Zhejiang Institute of Research and Innovation (HKU-ZIRI), Hangzhou, Zhejiang 311300, People's Republic of China
| | - Xing Cheng
- Pico Center and SUSTech Core Research Facilities, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
- Shenzhen Key Laboratory for Nanoimprint Technology, Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
| |
Collapse
|
5
|
Emmrich D, Wolff A, Meyerbröker N, Lindner JKN, Beyer A, Gölzhäuser A. Scanning transmission helium ion microscopy on carbon nanomembranes. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:222-231. [PMID: 33728240 PMCID: PMC7934706 DOI: 10.3762/bjnano.12.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
A dark-field scanning transmission ion microscopy detector was designed for the helium ion microscope. The detection principle is based on a secondary electron conversion holder with an exchangeable aperture strip allowing its acceptance angle to be tuned from 3 to 98 mrad. The contrast mechanism and performance were investigated using freestanding nanometer-thin carbon membranes. The results demonstrate that the detector can be optimized either for most efficient signal collection or for maximum image contrast. The designed setup allows for the imaging of thin low-density materials that otherwise provide little signal or contrast and for a clear end-point detection in the fabrication of nanopores. In addition, the detector is able to determine the thickness of membranes with sub-nanometer precision by quantitatively evaluating the image signal and comparing the results with Monte Carlo simulations. The thickness determined by the dark-field transmission detector is compared to X-ray photoelectron spectroscopy and energy-filtered transmission electron microscopy measurements.
Collapse
Affiliation(s)
- Daniel Emmrich
- Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| | - Annalena Wolff
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, 2 George St, Brisbane 4000, QLD, Australia
| | | | | | - André Beyer
- Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| | - Armin Gölzhäuser
- Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| |
Collapse
|
6
|
Li P, Chen S, Dai H, Yang Z, Chen Z, Wang Y, Chen Y, Peng W, Shan W, Duan H. Recent advances in focused ion beam nanofabrication for nanostructures and devices: fundamentals and applications. NANOSCALE 2021; 13:1529-1565. [PMID: 33432962 DOI: 10.1039/d0nr07539f] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The past few decades have witnessed growing research interest in developing powerful nanofabrication technologies for three-dimensional (3D) structures and devices to achieve nano-scale and nano-precision manufacturing. Among the various fabrication techniques, focused ion beam (FIB) nanofabrication has been established as a well-suited and promising technique in nearly all fields of nanotechnology for the fabrication of 3D nanostructures and devices because of increasing demands from industry and research. In this article, a series of FIB nanofabrication factors related to the fabrication of 3D nanostructures and devices, including mechanisms, instruments, processes, and typical applications of FIB nanofabrication, are systematically summarized and analyzed in detail. Additionally, current challenges and future development trends of FIB nanofabrication in this field are also given. This work intends to provide guidance for practitioners, researchers, or engineers who wish to learn more about the FIB nanofabrication technology that is driving the revolution in 3D nanostructures and devices.
Collapse
Affiliation(s)
- Ping Li
- National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, P. R. China.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Esteban Florez FL, Trofimov AA, Ievlev A, Qian S, Rondinone AJ, Khajotia SS. Advanced characterization of surface-modified nanoparticles and nanofilled antibacterial dental adhesive resins. Sci Rep 2020; 10:9811. [PMID: 32555360 PMCID: PMC7299952 DOI: 10.1038/s41598-020-66819-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/21/2020] [Indexed: 11/30/2022] Open
Abstract
Nanotechnology can improve the performance of dental polymers. The objective of this study was to modify the surfaces of nanoparticles with silanes and proteins, characterize nanoparticles' agglomeration levels and interfaces between nanoparticles and the polymeric matrix. Undoped (n-TiO2), nitrogen-doped (N_TiO2) and nitrogen-fluorine co-doped titanium dioxide nanoparticles (NF_TiO2) were synthesized and subjected to surface modification procedures in preparation for Small-Angle X-Ray Scattering (SAXS) and Small-Angle Neutron Scattering (SANS) characterizations. Experimental adhesives were manually synthesized by incorporating 20% (v/v) of n-TiO2, N_TiO2 or NF_TiO2 (as-synthesized or surface-modified) into OptiBond Solo Plus (OPTB). Specimens (n = 15/group; d = 6.0 mm, t = 0.5 mm) of OPTB and experimental adhesives were characterized using Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS), 2-D ToF-SIMS chemical imaging and SANS. SAXS results indicated that surface-modified nanoparticles displayed higher scattering intensities in a particle-size dependent manner. ToF-SIMS results demonstrated that nanoparticles' incorporation did not adversely impact the parental polymer. 2-D ToF-SIMS chemical imaging demonstrated the distribution of Ti+ and confirmed nitrogen-doping levels. SANS results confirmed nanoparticles' functionalization and revealed the interfaces between nanoparticles and the polymer matrix. Metaloxide nanoparticles were successfully fabricated, incorporated and covalently functionalized in a commercial dental adhesive resin, thereby supporting the utilization of nanotechnology in dentistry.
Collapse
Affiliation(s)
- Fernando Luis Esteban Florez
- The University of Oklahoma Health Sciences Center, Department of Restorative Sciences, Division of Dental Biomaterials, College of Dentistry, 1201 N. Stonewall Avenue, Oklahoma City, Oklahoma, 73117, USA.
| | - Artem A Trofimov
- Oak Ridge National Laboratory, Center for Nanophase Materials Sciences, Oak Ridge, Tennessee, 37831, USA
| | - Anton Ievlev
- Oak Ridge National Laboratory, Center for Nanophase Materials Sciences, Oak Ridge, Tennessee, 37831, USA
| | - Shuo Qian
- Oak Ridge National Laboratory, Neutron Scattering Division, Oak Ridge, Tennessee, 37831, USA
| | - Adam Justin Rondinone
- Oak Ridge National Laboratory, Center for Nanophase Materials Sciences, Oak Ridge, Tennessee, 37831, USA
| | - Sharukh Soli Khajotia
- The University of Oklahoma Health Sciences Center, Department of Restorative Sciences, Division of Dental Biomaterials, College of Dentistry, 1201 N. Stonewall Avenue, Oklahoma City, Oklahoma, 73117, USA
| |
Collapse
|
8
|
Moon DW, Park YH, Lee SY, Lim H, Kwak S, Kim MS, Kim H, Kim E, Jung Y, Hoe HS, Kim S, Lim DK, Kim CH, In SI. Multiplex Protein Imaging with Secondary Ion Mass Spectrometry Using Metal Oxide Nanoparticle-Conjugated Antibodies. ACS APPLIED MATERIALS & INTERFACES 2020; 12:18056-18064. [PMID: 32073828 DOI: 10.1021/acsami.9b21800] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In spite of recent developments in mass spectrometry imaging techniques, high-resolution multiplex protein bioimaging techniques are required to unveil the complex inter- and intracellular biomolecular interactions for accurate understanding of life phenomena and disease mechanisms. Herein, we report multiplex protein imaging with secondary ion mass spectrometry (SIMS) using metal oxide nanoparticle (MONP)-conjugated antibodies with <300 nm spatial resolution in the low ion dose without ion beam damage because of the high secondary ion yields of the MONPs, which can provide simultaneous imaging of several proteins, especially from cell membranes. We applied our new imaging technique for the study of hippocampal tissue samples from control and Alzheimer's disease (AD) model mice; the proximity of protein clusters in the hippocampus CA1 region showed intriguing dependence on aging and AD progress, suggesting that protein cluster proximity may be helpful for understanding pathological pathways in the microscopic cellular level.
Collapse
Affiliation(s)
- Dae Won Moon
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Young Ho Park
- Department of Energy Science and Engineering, DGIST, Daegu 42988, Republic of Korea
| | - Sun Young Lee
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Heejin Lim
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - SuHwa Kwak
- Department of Computer Science and Engineering, POSTECH, Pohang 37673, Republic of Korea
| | - Minseok S Kim
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Hyunmin Kim
- Companion Diagnostics and Medical Technology Research Group, DGIST, Daegu 42988, Republic of Korea
| | - Eunjoo Kim
- Companion Diagnostics and Medical Technology Research Group, DGIST, Daegu 42988, Republic of Korea
| | - Yebin Jung
- Department of Chemistry, POSTECH, Pohang 37673, Republic of Korea
| | - Hyang-Sook Hoe
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Republic of Korea
| | - Sungjee Kim
- Department of Chemistry, POSTECH, Pohang 37673, Republic of Korea
| | - Dong-Kwon Lim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Chul-Hoon Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Su-Il In
- Department of Energy Science and Engineering, DGIST, Daegu 42988, Republic of Korea
| |
Collapse
|
9
|
Peng M, Murray-Bruce J, Berggren KK, Goyal VK. Source shot noise mitigation in focused ion beam microscopy by time-resolved measurement. Ultramicroscopy 2020; 211:112948. [PMID: 32171978 DOI: 10.1016/j.ultramic.2020.112948] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 12/23/2019] [Accepted: 01/26/2020] [Indexed: 11/18/2022]
Abstract
Focused ion beam microscopy suffers from source shot noise - random variation in the number of incident ions in any fixed dwell time - along with random variation in the number of detected secondary electrons per incident ion. This multiplicity of sources of randomness increases the variance of the measurements and thus worsens the trade-off between incident ion dose and image accuracy. Repeated measurement with low dwell time, without changing the total ion dose, is a way to introduce time resolution to this form of microscopy. Through theoretical analyses and Monte Carlo simulations, we show that three ways to process time-resolved measurements result in mean-squared error (MSE) improvements compared to the conventional method of having no time resolution. In particular, maximum likelihood estimation provides reduction in MSE or reduction in required dose by a multiplicative factor approximately equal to the secondary electron yield. This improvement factor is similar to complete mitigation of source shot noise. Experiments with a helium ion microscope are consistent with the analyses and suggest accuracy improvement for a fixed source dose by a factor of about 4.
Collapse
Affiliation(s)
- Minxu Peng
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA
| | - John Murray-Bruce
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA
| | - Karl K Berggren
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Vivek K Goyal
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA.
| |
Collapse
|
10
|
Wirtz T, De Castro O, Audinot JN, Philipp P. Imaging and Analytics on the Helium Ion Microscope. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:523-543. [PMID: 30699036 DOI: 10.1146/annurev-anchem-061318-115457] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The helium ion microscope (HIM) has emerged as an instrument of choice for patterning, imaging and, more recently, analytics at the nanoscale. Here, we review secondary electron imaging on the HIM and the various methodologies and hardware components that have been developed to confer analytical capabilities to the HIM. Secondary electron-based imaging can be performed at resolutions down to 0.5 nm with high contrast, with high depth of field, and directly on insulating samples. Analytical methods include secondary electron hyperspectral imaging (SEHI), scanning transmission ion microscopy (STIM), backscattering spectrometry and, in particular, secondary ion mass spectrometry (SIMS). The SIMS system that was specifically designed for the HIM allows the detection of all elements, the differentiation between isotopes, and the detection of trace elements. It provides mass spectra, depth profiles, and 2D or 3D images with lateral resolutions down to 10 nm.
Collapse
Affiliation(s)
- Tom Wirtz
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
| | - Olivier De Castro
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
| | - Jean-Nicolas Audinot
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
| | - Patrick Philipp
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
| |
Collapse
|
11
|
Pöpsel C, Becker J, Jeon N, Döblinger M, Stettner T, Gottschalk YT, Loitsch B, Matich S, Altzschner M, Holleitner AW, Finley JJ, Lauhon LJ, Koblmüller G. He-Ion Microscopy as a High-Resolution Probe for Complex Quantum Heterostructures in Core-Shell Nanowires. NANO LETTERS 2018; 18:3911-3919. [PMID: 29781624 DOI: 10.1021/acs.nanolett.8b01282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Core-shell semiconductor nanowires (NW) with internal quantum heterostructures are amongst the most complex nanostructured materials to be explored for assessing the ultimate capabilities of diverse ultrahigh-resolution imaging techniques. To probe the structure and composition of these materials in their native environment with minimal damage and sample preparation calls for high-resolution electron or ion microscopy methods, which have not yet been tested on such classes of ultrasmall quantum nanostructures. Here, we demonstrate that scanning helium ion microscopy (SHeIM) provides a powerful and straightforward method to map quantum heterostructures embedded in complex III-V semiconductor NWs with unique material contrast at ∼1 nm resolution. By probing the cross sections of GaAs-Al(Ga)As core-shell NWs with coaxial GaAs quantum wells as well as short-period GaAs/AlAs superlattice (SL) structures in the shell, the Al-rich and Ga-rich layers are accurately discriminated by their image contrast in excellent agreement with correlated, yet destructive, scanning transmission electron microscopy and atom probe tomography analysis. Most interestingly, quantitative He-ion dose-dependent SHeIM analysis of the ternary AlGaAs shell layers and of compositionally nonuniform GaAs/AlAs SLs reveals distinct alloy composition fluctuations in the form of Al-rich clusters with size distributions between ∼1-10 nm. In the GaAs/AlAs SLs the alloy clustering vanishes with increasing SL-period (>5 nm-GaAs/4 nm-AlAs), providing insights into critical size dimensions for atomic intermixing effects in short-period SLs within a NW geometry. The straightforward SHeIM technique therefore provides unique benefits in imaging the tiniest nanoscale features in topography, structure and composition of a multitude of diverse complex semiconductor nanostructures.
Collapse
Affiliation(s)
- Christian Pöpsel
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Jonathan Becker
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Nari Jeon
- Department of Materials Science & Engineering , Northwestern University , Evanston , Illinois 60208 , United States
| | - Markus Döblinger
- Department of Chemistry , Ludwig-Maximilian-Universität München , Butenandtstraße 5-13 , München , 81377 , Germany
| | - Thomas Stettner
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Yeanitza Trujillo Gottschalk
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Bernhard Loitsch
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Sonja Matich
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Marcus Altzschner
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Alexander W Holleitner
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Jonathan J Finley
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Lincoln J Lauhon
- Department of Materials Science & Engineering , Northwestern University , Evanston , Illinois 60208 , United States
| | - Gregor Koblmüller
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| |
Collapse
|
12
|
Chemical Changes in Layered Ferroelectric Semiconductors Induced by Helium Ion Beam. Sci Rep 2017; 7:16619. [PMID: 29192283 PMCID: PMC5709364 DOI: 10.1038/s41598-017-16949-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 11/20/2017] [Indexed: 11/11/2022] Open
Abstract
Multi-material systems interfaced with 2D materials, or entirely new 3D heterostructures can lead to the next generation multi-functional device architectures. Physical and chemical control at the nanoscale is also necessary tailor these materials as functional structures approach physical limit. 2D transition metal thiophosphates (TPS), with a general formulae Cu1−xIn1+x/3P2S6, have shown ferroelectric polarization behavior with a Tc above the room temperature, making them attractive candidates for designing both: chemical and physical properties. Our previous studies have demonstrated that ferroic order persists on the surface, and that spinoidal decomposition of ferroelectric and paraelectric phases occurs in non-stoichiometric Cu/In ratio formulations. Here, we discuss the chemical changes induced by helium ion irradiation. We explore the TPS compound library with varying Cu/In ratio, using Helium Ion Microscopy, Atomic Force Microscopy (AFM), and Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS). We correlate physical nano- and micro- structures to the helium ion dose, as well as chemical signatures of copper, oxygen and sulfur. Our ToF-SIMS results show that He ion irradiation leads to oxygen penetration into the irradiated areas, and diffuses along the Cu-rich domains to the extent of the stopping distance of the helium ions.
Collapse
|
13
|
Dowsett D, Wirtz T. Co-Registered In Situ Secondary Electron and Mass Spectral Imaging on the Helium Ion Microscope Demonstrated Using Lithium Titanate and Magnesium Oxide Nanoparticles. Anal Chem 2017; 89:8957-8965. [PMID: 28771307 DOI: 10.1021/acs.analchem.7b01481] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The development of a high resolution elemental imaging platform combining coregistered secondary ion mass spectrometry and high resolution secondary electron imaging is reported. The basic instrument setup and operation are discussed and in situ image correlation is demonstrated on a lithium titanate and magnesium oxide nanoparticle mixture. The instrument uses both helium and neon ion beams generated by a gas field ion source to irradiate the sample. Both secondary electrons and secondary ions may be detected. Secondary ion mass spectrometry (SIMS) is performed using an in-house developed double focusing magnetic sector spectrometer with parallel detection. Spatial resolutions of 10 nm have been obtained in SIMS mode. Both the secondary electron and SIMS image data are very surface sensitive and have approximately the same information depth. While the spatial resolutions are approximately a factor of 10 different, switching between the different images modes may be done in situ and extremely rapidly, allowing for simple imaging of the same region of interest and excellent coregistration of data sets. The ability to correlate mass spectral images on the 10 nm scale with secondary electron images on the nanometer scale in situ has the potential to provide a step change in our understanding of nanoscale phenomena in fields from materials science to life science.
Collapse
Affiliation(s)
- D Dowsett
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST) , Belvaux, Luxembourg
| | - T Wirtz
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST) , Belvaux, Luxembourg
| |
Collapse
|
14
|
Schmidt ME, Yasaka A, Akabori M, Mizuta H. Nitrogen Gas Field Ion Source (GFIS) Focused Ion Beam (FIB) Secondary Electron Imaging: A First Look. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:758-768. [PMID: 28487005 DOI: 10.1017/s1431927617000502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The recent technological advance of the gas field ion source (GFIS) and its successful integration into systems has renewed the interest in the focused ion beam (FIB) technology. Due to the atomically small source size and the use of light ions, the limitations of the liquid metal ion source are solved as device dimensions are pushed further towards the single-digit nanometer size. Helium and neon ions are the most widely used, but a large portfolio of available ion species is desirable, to allow a wide range of applications. Among argon and hydrogen, $${\rm N}_{2}^{{\plus}} $$ ions offer unique characteristics due to their covalent bond and their use as dopant for various carbon-based materials including diamond. Here, we provide a first look at the $${\rm N}_{2}^{{\plus}} $$ GFIS-FIB enabled imaging of a large selection of microscopic structures, including gold on carbon test specimen, thin metal films on insulator and nanostructured carbon-based devices, which are among the most actively researched materials in the field of nanoelectronics. The results are compared with images acquired by He+ ions, and we show that $${\rm N}_{2}^{{\plus}} $$ GFIS-FIB can offer improved material contrast even at very low imaging dose and is more sensitive to the surface roughness.
Collapse
Affiliation(s)
- Marek E Schmidt
- 1School of Materials Science,Japan Advanced Institute of Science and Technology,1-1 Asahidai,Nomi,923-1292,Japan
| | - Anto Yasaka
- 1School of Materials Science,Japan Advanced Institute of Science and Technology,1-1 Asahidai,Nomi,923-1292,Japan
| | - Masashi Akabori
- 1School of Materials Science,Japan Advanced Institute of Science and Technology,1-1 Asahidai,Nomi,923-1292,Japan
| | - Hiroshi Mizuta
- 1School of Materials Science,Japan Advanced Institute of Science and Technology,1-1 Asahidai,Nomi,923-1292,Japan
| |
Collapse
|
15
|
Mahady K, Tan S, Greenzweig Y, Livengood R, Raveh A, Rack P. Monte Carlo simulations of nanoscale Ne + ion beam sputtering: investigating the influence of surface effects, interstitial formation, and the nanostructural evolution. NANOTECHNOLOGY 2017; 28:045305. [PMID: 27991448 DOI: 10.1088/1361-6528/28/4/045305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present an updated version of our Monte-Carlo based code for the simulation of ion beam sputtering. This code simulates the interaction of energetic ions with a target, and tracks the cumulative damage, enabling it to simulate the dynamic evolution of nanostructures as material is removed. The updated code described in this paper is significantly faster, permitting the inclusion of new features, namely routines to handle interstitial atoms, and to reduce the surface energy as the structure would otherwise develop energetically unfavorable surface porosity. We validate our code against the popular Monte-Carlo code SRIM-TRIM, and study the development of nanostructures from Ne+ ion beam milling in a copper target.
Collapse
Affiliation(s)
- Kyle Mahady
- University of Tennessee Knoxville, TN 37996, USA
| | | | | | | | | | | |
Collapse
|
16
|
Zheng W, Li P, van den Hurk R, Evoy S. Helium Ion Microscope-Assisted Nanomachining of Resonant Nanostrings. SENSORS 2016; 16:s16071080. [PMID: 27420070 PMCID: PMC4970126 DOI: 10.3390/s16071080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 07/05/2016] [Accepted: 07/08/2016] [Indexed: 11/16/2022]
Abstract
Helium ion microscopy has recently emerged as a potent tool for the in-situ modification and imaging of nanoscale devices. For example; finely focused helium ion beams have been used for the milling of pores in suspended structures. We here report the use of helium ion milling for the post-fabrication modification of nanostrings machined from an amorphous SiCN material. The modification consisted of milling linear arrays of holes along the length of nanostrings. This milling results in a slight decrease of resonant frequency while increasing the surface to volume ratio of the device. The frequency decrease is attributed to a reduction of the effective Young’s modulus of the string, which in turn reduces the tension the string is under. Such experimental observations are supported by the finite element analysis of milled and non-milled strings.
Collapse
Affiliation(s)
- Wei Zheng
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| | - Peng Li
- Nanofab, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| | - Remko van den Hurk
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| | - Stephane Evoy
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| |
Collapse
|
17
|
Huh U, Cho W, Joy DC. Monte Carlo modeling of ion beam induced secondary electrons. Ultramicroscopy 2016; 168:28-33. [PMID: 27337603 DOI: 10.1016/j.ultramic.2016.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 05/08/2016] [Accepted: 05/25/2016] [Indexed: 11/29/2022]
Abstract
Ion induced secondary electrons (iSE) can produce high-resolution images ranging from a few eV to 100keV over a wide range of materials. The interpretation of such images requires knowledge of the secondary electron yields (iSE δ) for each of the elements and materials present and as a function of the incident beam energy. Experimental data for helium ions are currently limited to 40 elements and six compounds while other ions are not well represented. To overcome this limitation, we propose a simple procedure based on the comprehensive work of Berger et al. Here we show that between the energy range of 10-100keV the Berger et al. data for elements and compounds can be accurately represented by a single universal curve. The agreement between the limited experimental data that is available and the predictive model is good, and has been found to provide reliable yield data for a wide range of elements and compounds.
Collapse
Affiliation(s)
- U Huh
- Biochemistry & Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840, USA.
| | - W Cho
- Electrical and Computer Engineering, University of Tennessee, Knoxville, TN 37996-2100, USA
| | - D C Joy
- Biochemistry & Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840, USA; Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
18
|
McClelland JJ, Steele AV, Knuffman B, Twedt KA, Schwarzkopf A, Wilson TM. Bright focused ion beam sources based on laser-cooled atoms. APPLIED PHYSICS REVIEWS 2016; 3:011302. [PMID: 27239245 PMCID: PMC4882766 DOI: 10.1063/1.4944491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a new type of FIB source has emerged, which uses ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with laser cooling (in the range of 100 μK or below) result in a beam of ions with a very small transverse velocity distribution. This corresponds to a source with extremely high brightness that rivals or may even exceed the brightness of the industry standard Ga+ liquid metal ion source. In this review we discuss the context of ion beam technology in which these new ion sources can play a role, their principles of operation, and some examples of recent demonstrations. The field is relatively new, so only a few applications have been demonstrated, most notably low energy ion microscopy with Li ions. Nevertheless, a number of promising new approaches have been proposed and/or demonstrated, suggesting that a rapid evolution of this type of source is likely in the near future.
Collapse
Affiliation(s)
- J J McClelland
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - A V Steele
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899; zeroK NanoTech, Gaithersburg, MD 20878
| | - B Knuffman
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899; zeroK NanoTech, Gaithersburg, MD 20878
| | - K A Twedt
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899; Maryland Nanocenter, University of Maryland, College Park, MD 20742
| | - A Schwarzkopf
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899; zeroK NanoTech, Gaithersburg, MD 20878
| | - T M Wilson
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899
| |
Collapse
|
19
|
Zhou Y, Fox DS, Maguire P, O'Connell R, Masters R, Rodenburg C, Wu H, Dapor M, Chen Y, Zhang H. Quantitative secondary electron imaging for work function extraction at atomic level and layer identification of graphene. Sci Rep 2016; 6:21045. [PMID: 26878907 PMCID: PMC4754635 DOI: 10.1038/srep21045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 11/25/2015] [Indexed: 12/18/2022] Open
Abstract
Two-dimensional (2D) materials usually have a layer-dependent work function, which require fast and accurate detection for the evaluation of their device performance. A detection technique with high throughput and high spatial resolution has not yet been explored. Using a scanning electron microscope, we have developed and implemented a quantitative analytical technique which allows effective extraction of the work function of graphene. This technique uses the secondary electron contrast and has nanometre-resolved layer information. The measurement of few-layer graphene flakes shows the variation of work function between graphene layers with a precision of less than 10 meV. It is expected that this technique will prove extremely useful for researchers in a broad range of fields due to its revolutionary throughput and accuracy.
Collapse
Affiliation(s)
- Yangbo Zhou
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland
| | - Daniel S Fox
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland
| | - Pierce Maguire
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland
| | - Robert O'Connell
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland
| | - Robert Masters
- Department of Materials Science and Engineering, the University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD,United Kingdom
| | - Cornelia Rodenburg
- Department of Materials Science and Engineering, the University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD,United Kingdom
| | - Hanchun Wu
- Key Laboratory of Cluster Science of Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Maurizio Dapor
- European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-FBK) and Trento Institute for Fundamental Physics and Applications (TIFPA-INFN), via Sommarive 18, Trento I-38123, Italy
| | - Ying Chen
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Hongzhou Zhang
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland
| |
Collapse
|
20
|
Chee AK, Boden SA. Dopant profiling based on scanning electron and helium ion microscopy. Ultramicroscopy 2016; 161:51-58. [DOI: 10.1016/j.ultramic.2015.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Accepted: 10/06/2015] [Indexed: 11/29/2022]
|
21
|
Klingner N, Heller R, Hlawacek G, Borany JV, Notte J, Huang J, Facsko S. Nanometer scale elemental analysis in the helium ion microscope using time of flight spectrometry. Ultramicroscopy 2015; 162:91-97. [PMID: 26725148 DOI: 10.1016/j.ultramic.2015.12.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/30/2015] [Accepted: 12/15/2015] [Indexed: 11/16/2022]
Abstract
Time of flight backscattering spectrometry (ToF-BS) was successfully implemented in a helium ion microscope (HIM). Its integration introduces the ability to perform laterally resolved elemental analysis as well as elemental depth profiling on the nm scale. A lateral resolution of ≤54nm and a time resolution of Δt≤17ns(Δt/t≤5.4%) are achieved. By using the energy of the backscattered particles for contrast generation, we introduce a new imaging method to the HIM allowing direct elemental mapping as well as local spectrometry. In addition laterally resolved time of flight secondary ion mass spectrometry (ToF-SIMS) can be performed with the same setup. Time of flight is implemented by pulsing the primary ion beam. This is achieved in a cost effective and minimal invasive way that does not influence the high resolution capabilities of the microscope when operating in standard secondary electron (SE) imaging mode. This technique can thus be easily adapted to existing devices. The particular implementation of ToF-BS and ToF-SIMS techniques are described, results are presented and advantages, difficulties and limitations of this new techniques are discussed.
Collapse
Affiliation(s)
- N Klingner
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany; Technical University Dresden, 01062 Dresden, Germany.
| | - R Heller
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - G Hlawacek
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - J von Borany
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - J Notte
- Ion Microscopy Innovation Center at Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - J Huang
- Ion Microscopy Innovation Center at Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - S Facsko
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| |
Collapse
|
22
|
Maas DJ, Fliervoet T, Herfst R, van Veldhoven E, Meessen J, Vaenkatesan V, Sadeghian H. Sub-50 nm metrology on extreme ultra violet chemically amplified resist--A systematic assessment. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:103702. [PMID: 26520961 DOI: 10.1063/1.4932038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
With lithographic patterning dimensions decreasing well below 50 nm, it is of high importance to understand metrology at such small scales. This paper presents results obtained from dense arrays of contact holes (CHs) with various Critical Dimension (CD) between 15 and 50 nm, as patterned in a chemically amplified resist using an ASML EUV scanner and measured at ASML and TNO. To determine the differences between various (local) CD metrology techniques, we conducted an experiment using optical scatterometry, CD-Scanning Electron Microscopy (CD-SEM), Helium ion Microscopy (HIM), and Atomic Force Microscopy (AFM). CD-SEM requires advanced beam scan strategies to mitigate sample charging; the other tools did not need that. We discuss the observed main similarities and differences between the various techniques. To this end, we assessed the spatial frequency content in the raw images for SEM, HIM, and AFM. HIM and AFM resolve the highest spatial frequencies, which are attributed to the more localized probe-sample interaction for these techniques. Furthermore, the SEM, HIM, and AFM waveforms are analyzed in detail. All techniques show good mutual correlation, albeit the reported CD values systematically differ significantly. HIM systematically reports a 25% higher CD uniformity number than CD-SEM for the same arrays of CHs, probably because HIM has a higher resolution than the CD-SEM used in this assessment. A significant speed boost for HIM and AFM is required before these techniques are to serve the demanding industrial metrology applications like optical critical dimension and CD-SEM do nowadays.
Collapse
Affiliation(s)
- D J Maas
- Netherlands Organization for Applied Scientific Research, TNO, Stieltjesweg 1, 2628CK Delft, The Netherlands
| | - T Fliervoet
- ASML, de Run 6665, 5504DR Veldhoven, The Netherlands
| | - R Herfst
- Netherlands Organization for Applied Scientific Research, TNO, Stieltjesweg 1, 2628CK Delft, The Netherlands
| | - E van Veldhoven
- Netherlands Organization for Applied Scientific Research, TNO, Stieltjesweg 1, 2628CK Delft, The Netherlands
| | - J Meessen
- ASML, de Run 6665, 5504DR Veldhoven, The Netherlands
| | - V Vaenkatesan
- ASML, de Run 6665, 5504DR Veldhoven, The Netherlands
| | - H Sadeghian
- Netherlands Organization for Applied Scientific Research, TNO, Stieltjesweg 1, 2628CK Delft, The Netherlands
| |
Collapse
|
23
|
Iberi V, Vlassiouk I, Zhang XG, Matola B, Linn A, Joy DC, Rondinone AJ. Maskless Lithography and in situ Visualization of Conductivity of Graphene using Helium Ion Microscopy. Sci Rep 2015; 5:11952. [PMID: 26150202 PMCID: PMC4493665 DOI: 10.1038/srep11952] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/10/2015] [Indexed: 11/30/2022] Open
Abstract
The remarkable mechanical and electronic properties of graphene make it an ideal candidate for next generation nanoelectronics. With the recent development of commercial-level single-crystal graphene layers, the potential for manufacturing household graphene-based devices has improved, but significant challenges still remain with regards to patterning the graphene into devices. In the case of graphene supported on a substrate, traditional nanofabrication techniques such as e-beam lithography (EBL) are often used in fabricating graphene nanoribbons but the multi-step processes they require can result in contamination of the graphene with resists and solvents. In this letter, we report the utility of scanning helium ion lithography for fabricating functional graphene nanoconductors that are supported directly on a silicon dioxide layer, and we measure the minimum feature size achievable due to limitations imposed by thermal fluctuations and ion scattering during the milling process. Further we demonstrate that ion beams, due to their positive charging nature, may be used to observe and test the conductivity of graphene-based nanoelectronic devices in situ.
Collapse
Affiliation(s)
- Vighter Iberi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Ivan Vlassiouk
- Energy and Transportation Science, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - X-G Zhang
- 1] Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA [2] Department of Physics and Quantum Theory Project, University of Florida, Gainesville, FL 32611
| | - Brad Matola
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Allison Linn
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - David C Joy
- 1] Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA [2] Department of Materials Science &Engineering, University of Tennessee Knoxville, TN 37996
| | - Adam J Rondinone
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
24
|
Petrov YV, Vyvenko OF. Scanning reflection ion microscopy in a helium ion microscope. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:1125-1137. [PMID: 26171289 PMCID: PMC4463972 DOI: 10.3762/bjnano.6.114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/15/2015] [Indexed: 06/04/2023]
Abstract
Reflection ion microscopy (RIM) is a technique that uses a low angle of incidence and scattered ions to form an image of the specimen surface. This paper reports on the development of the instrumentation and the analysis of the capabilities and limitations of the scanning RIM in a helium ion microscope (HIM). The reflected ions were detected by their "conversion" to secondary electrons on a platinum surface. An angle of incidence in the range 5-10° was used in the experimental setup. It was shown that the RIM image contrast was determined mostly by surface morphology but not by the atomic composition. A simple geometrical analysis of the reflection process was performed together with a Monte Carlo simulation of the angular dependence of the reflected ion yield. An interpretation of the RIM image formation and a quantification of the height of the surface steps were performed. The minimum detectable step height was found to be approximately 5 nm. RIM imaging of an insulator surface without the need for charge compensation was successfully demonstrated.
Collapse
Affiliation(s)
- Yuri V Petrov
- Interdisciplinary Resource Center for Nanotechnology, Saint-Petersburg State University, Ulyanovskaya 1, Saint-Petersburg 198504, Russia
| | - Oleg F Vyvenko
- Faculty of Physics, Saint-Petersburg State University, Ulyanovskaya 1, Saint-Petersburg 198504, Russia
| |
Collapse
|
25
|
Robertson C, Beanland R, Boden SA, Hector AL, Kashtiban RJ, Sloan J, Smith DC, Walcarius A. Ordered mesoporous silica films with pores oriented perpendicular to a titanium nitride substrate. Phys Chem Chem Phys 2015; 17:4763-70. [DOI: 10.1039/c4cp05730a] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thin mesoporous films are demonstrated with pores oriented perpendicular to a titanium nitride growth surface.
Collapse
Affiliation(s)
| | | | - Stuart A. Boden
- Electronics and Computer Science
- University of Southampton
- Southampton SO17 1BJ
- UK
| | | | | | - Jeremy Sloan
- Department of Physics
- University of Warwick
- Coventry CV4 7AL
- UK
| | - David C. Smith
- Physics and Astronomy
- University of Southampton
- Southampton SO17 1BJ
- UK
| | - Alain Walcarius
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement
- UMR 7564
- CNRS-Université de Lorraine
- 54600 Villers-les-Nancy
- France
| |
Collapse
|
26
|
Twedt KA, Chen L, McClelland JJ. Scanning ion microscopy with low energy lithium ions. Ultramicroscopy 2014; 142:24-31. [PMID: 24751577 DOI: 10.1016/j.ultramic.2014.03.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/26/2014] [Accepted: 03/29/2014] [Indexed: 10/25/2022]
Abstract
Using an ion source based on photoionization of laser-cooled lithium atoms, we have developed a scanning ion microscope with probe sizes of a few tens of nanometers and beam energies from 500eV to 5keV. These beam energies are much lower than the typical operating energies of the helium ion microscope or gallium focused ion beam systems. We demonstrate how low energy can be advantageous in ion microscopy when detecting backscattered ions, due to a decreased interaction volume and the potential for surface sensitive composition analysis. As an example application that demonstrates these advantages, we non-destructively image the removal of a thin residual resist layer during plasma etching in a nano-imprint lithography process.
Collapse
Affiliation(s)
- Kevin A Twedt
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA; Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA
| | - Lei Chen
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Jabez J McClelland
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
| |
Collapse
|
27
|
Zhang X, Vieker H, Beyer A, Gölzhäuser A. Fabrication of carbon nanomembranes by helium ion beam lithography. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:188-94. [PMID: 24605285 PMCID: PMC3943867 DOI: 10.3762/bjnano.5.20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 01/22/2014] [Indexed: 06/01/2023]
Abstract
The irradiation-induced cross-linking of aromatic self-assembled monolayers (SAMs) is a universal method for the fabrication of ultrathin carbon nanomembranes (CNMs). Here we demonstrate the cross-linking of aromatic SAMs due to exposure to helium ions. The distinction of cross-linked from non-cross-linked regions in the SAM was facilitated by transferring the irradiated SAM to a new substrate, which allowed for an ex situ observation of the cross-linking process by helium ion microscopy (HIM). In this way, three growth regimes of cross-linked areas were identified: formation of nuclei, one-dimensional (1D) and two-dimensional (2D) growth. The evaluation of the corresponding HIM images revealed the dose-dependent coverage, i.e., the relative monolayer area, whose density of cross-links surpassed a certain threshold value, as a function of the exposure dose. A complete cross-linking of aromatic SAMs by He(+) ion irradiation requires an exposure dose of about 850 µC/cm(2), which is roughly 60 times smaller than the corresponding electron irradiation dose. Most likely, this is due to the energy distribution of secondary electrons shifted to lower energies, which results in a more efficient dissociative electron attachment (DEA) process.
Collapse
Affiliation(s)
- Xianghui Zhang
- Department of Physics, Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| | - Henning Vieker
- Department of Physics, Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| | - André Beyer
- Department of Physics, Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| | - Armin Gölzhäuser
- Department of Physics, Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| |
Collapse
|
28
|
Joens MS, Huynh C, Kasuboski JM, Ferranti D, Sigal YJ, Zeitvogel F, Obst M, Burkhardt CJ, Curran KP, Chalasani SH, Stern LA, Goetze B, Fitzpatrick JAJ. Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution. Sci Rep 2013; 3:3514. [PMID: 24343236 PMCID: PMC3865489 DOI: 10.1038/srep03514] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 11/26/2013] [Indexed: 11/08/2022] Open
Abstract
Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.
Collapse
Affiliation(s)
- Matthew S. Joens
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Chuong Huynh
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - James M. Kasuboski
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - David Ferranti
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - Yury J. Sigal
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Fabian Zeitvogel
- Center for Applied Geosciences, University Tübingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany
| | - Martin Obst
- Center for Applied Geosciences, University Tübingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany
| | - Claus J. Burkhardt
- NMI Natural and Medical Sciences Institute, Markwiesenstr. 55, 72770 Reutlingen, Germany
| | - Kevin P. Curran
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Sreekanth H. Chalasani
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lewis A. Stern
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - Bernhard Goetze
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - James A. J. Fitzpatrick
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| |
Collapse
|
29
|
Hlawacek G, Ahmad I, Smithers MA, Kooij ES. To see or not to see: Imaging surfactant coated nano-particles using HIM and SEM. Ultramicroscopy 2013; 135:89-94. [DOI: 10.1016/j.ultramic.2013.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/09/2013] [Accepted: 07/14/2013] [Indexed: 10/26/2022]
|
30
|
Fox D, Zhou YB, O'Neill A, Kumar S, Wang JJ, Coleman JN, Duesberg GS, Donegan JF, Zhang HZ. Helium ion microscopy of graphene: beam damage, image quality and edge contrast. NANOTECHNOLOGY 2013; 24:335702. [PMID: 23883614 DOI: 10.1088/0957-4484/24/33/335702] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A study to analyse beam damage, image quality and edge contrast in the helium ion microscope (HIM) has been undertaken. The sample investigated was graphene. Raman spectroscopy was used to quantify the disorder that can be introduced into the graphene as a function of helium ion dose. The effects of the dose on both freestanding and supported graphene were compared. These doses were then correlated directly to image quality by imaging graphene flakes at high magnification. It was found that a high magnification image with a good signal to noise ratio will introduce very significant sample damage. A safe imaging dose of the order of 10(13) He(+) cm(-2) was established, with both graphene samples becoming highly defective at doses over 5 × 10(14) He(+) cm(-2).The edge contrast of a freestanding graphene flake imaged in the HIM was then compared with the contrast of the same flake observed in a scanning electron microscope and a transmission electron microscope. Very strong edge sensitivity was observed in the HIM. This enhanced edge sensitivity over the other techniques investigated makes the HIM a powerful nanoscale dimensional metrology tool, with the capability of both fabricating and imaging features with sub-nanometre resolution.
Collapse
Affiliation(s)
- D Fox
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Republic of Ireland
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
The interaction of a nanoscale coherent helium-ion probe with a crystal. Ultramicroscopy 2013; 134:18-22. [PMID: 23876709 DOI: 10.1016/j.ultramic.2013.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 06/17/2013] [Accepted: 06/26/2013] [Indexed: 11/22/2022]
Abstract
Thickness fringing was recently observed in helium ion microscopy (HIM) when imaging magnesium oxide cubes using a 40 keV convergent probe in scanning transmission mode. Thickness fringing is also observed in electron microscopy and is due to quantum mechanical, coherent, multiple elastic scattering attenuated by inelastic phonon excitation (thermal scattering). A quantum mechanical model for elastic scattering and phonon excitation correctly models the thickness fringes formed by the helium ions. However, unlike the electron case, the signal in the diffraction plane is due mainly to the channeling of ions which have first undergone inelastic thermal scattering in the first few atomic layers so that the origin of the thickness fringes is not due to coherent interference effects. This quantum mechanical model affords insight into the interaction of a nanoscale, focused coherent ion probe with the specimen and allows us to elucidate precisely what is needed to achieve atomic resolution HIM.
Collapse
|
32
|
Veligura V, Hlawacek G, Berkelaar RP, van Gastel R, Zandvliet HJW, Poelsema B. Digging gold: keV He(+) ion interaction with Au. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2013; 4:453-60. [PMID: 23946914 PMCID: PMC3740815 DOI: 10.3762/bjnano.4.53] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 06/20/2013] [Indexed: 05/25/2023]
Abstract
Helium ion microscopy (HIM) was used to investigate the interaction of a focused He(+) ion beam with energies of several tens of kiloelectronvolts with metals. HIM is usually applied for the visualization of materials with extreme surface sensitivity and resolution. However, the use of high ion fluences can lead to significant sample modifications. We have characterized the changes caused by a focused He(+) ion beam at normal incidence to the Au{111} surface as a function of ion fluence and energy. Under the influence of the beam a periodic surface nanopattern develops. The periodicity of the pattern shows a power-law dependence on the ion fluence. Simultaneously, helium implantation occurs. Depending on the fluence and primary energy, porous nanostructures or large blisters form on the sample surface. The growth of the helium bubbles responsible for this effect is discussed.
Collapse
Affiliation(s)
- Vasilisa Veligura
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Gregor Hlawacek
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Robin P Berkelaar
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Raoul van Gastel
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Harold J W Zandvliet
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Bene Poelsema
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| |
Collapse
|
33
|
Hall AR. In situ thickness assessment during ion milling of a free-standing membrane using transmission helium ion microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19:740-744. [PMID: 23628344 DOI: 10.1017/s1431927613000500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We describe a novel method for in situ measurement of the local thickness of a freely suspended solid-state membrane after thinning with a focused helium ion beam. The technique utilizes a custom stage for the helium ion microscope that allows the secondary electron detector used for normal imaging to collect information from ions transmitted through the sample. We find that relative brightness in the transmission image scales directly with the membrane thickness as determined by atomic force microscopy measurements.
Collapse
Affiliation(s)
- Adam R Hall
- Joint School of Nanoscience and Nanoengineering, Department of Nanoscience, University of North Carolina Greensboro, Greensboro, NC 27401, USA.
| |
Collapse
|
34
|
Timilsina R, Smith DA, Rack PD. A comparison of neon versus helium ion beam induced deposition via Monte Carlo simulations. NANOTECHNOLOGY 2013; 24:115302. [PMID: 23449368 DOI: 10.1088/0957-4484/24/11/115302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The ion beam induced nanoscale synthesis of PtCx (where x ∼ 5) using the trimethyl (methylcyclopentadienyl)platinum(IV) (MeCpPt(IV)Me3) precursor is investigated by performing Monte Carlo simulations of helium and neon ions. The helium beam leads to more lateral growth relative to the neon beam because of its larger interaction volume. The lateral growth of the nanopillars is dominated by molecules deposited via secondary electrons in both the simulations. Notably, the helium pillars are dominated by SE-I electrons whereas the neon pillars are dominated by SE-II electrons. Using a low precursor residence time of 70 μs, resulting in an equilibrium coverage of ∼4%, the neon simulation has a lower deposition efficiency (3.5%) compared to that of the helium simulation (6.5%). At larger residence time (10 ms) and consequently larger equilibrium coverage (85%) the deposition efficiencies of helium and neon increased to 49% and 21%, respectively; which is dominated by increased lateral growth rates leading to broader pillars. The nanoscale growth is further studied by varying the ion beam diameter at 10 ms precursor residence time. The study shows that total SE yield decreases with increasing beam diameters for both the ion types. However, helium has the larger SE yield as compared to that of neon in both the low and high precursor residence time, and thus pillars are wider in all the simulations studied.
Collapse
Affiliation(s)
- Rajendra Timilsina
- Department of Material Science and Engineering, University of Tennessee, Knoxville, TN 37996-2200, USA
| | | | | |
Collapse
|
35
|
|
36
|
Wu L, Egerton R, Zhu Y. Image simulation for atomic resolution secondary electron image. Ultramicroscopy 2012; 123:66-73. [DOI: 10.1016/j.ultramic.2012.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 06/11/2012] [Accepted: 06/11/2012] [Indexed: 10/28/2022]
|
37
|
Abstract
From the nearly mass-less electron to massive ions, charged particle microscopes have diversified over the last few decades. At present, a broad range of available charged particles with varying masses fulfill many applications: from imaging to analysis to nanofabrication.
Collapse
|
38
|
Hlawacek G, Veligura V, Lorbek S, Mocking TF, George A, van Gastel R, Zandvliet HJW, Poelsema B. Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2012; 3:507-12. [PMID: 23019545 PMCID: PMC3458595 DOI: 10.3762/bjnano.3.58] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 06/15/2012] [Indexed: 05/24/2023]
Abstract
BACKGROUND Helium ion microscopy is a new high-performance alternative to classical scanning electron microscopy. It provides superior resolution and high surface sensitivity by using secondary electrons. RESULTS We report on a new contrast mechanism that extends the high surface sensitivity that is usually achieved in secondary electron images, to backscattered helium images. We demonstrate how thin organic and inorganic layers as well as self-assembled monolayers can be visualized on heavier element substrates by changes in the backscatter yield. Thin layers of light elements on heavy substrates should have a negligible direct influence on backscatter yields. However, using simple geometric calculations of the opaque crystal fraction, the contrast that is observed in the images can be interpreted in terms of changes in the channeling probability. CONCLUSION The suppression of ion channeling into crystalline matter by adsorbed thin films provides a new contrast mechanism for HIM. This dechanneling contrast is particularly well suited for the visualization of ultrathin layers of light elements on heavier substrates. Our results also highlight the importance of proper vacuum conditions for channeling-based experimental methods.
Collapse
Affiliation(s)
- Gregor Hlawacek
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Vasilisa Veligura
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Stefan Lorbek
- Institute for Physics, Montanuniversitaet Leoben, Franz Josef Straße 18, 8700 Leoben, Austria
| | - Tijs F Mocking
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Antony George
- Inorganic Material Science, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Raoul van Gastel
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Harold J W Zandvliet
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Bene Poelsema
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| |
Collapse
|
39
|
Veligura V, Hlawacek G, van Gastel R, Zandvliet HJW, Poelsema B. Channeling in helium ion microscopy: Mapping of crystal orientation. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2012; 3:501-6. [PMID: 23019544 PMCID: PMC3458594 DOI: 10.3762/bjnano.3.57] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 06/14/2012] [Indexed: 05/31/2023]
Abstract
BACKGROUND The unique surface sensitivity and the high resolution that can be achieved with helium ion microscopy make it a competitive technique for modern materials characterization. As in other techniques that make use of a charged particle beam, channeling through the crystal structure of the bulk of the material can occur. RESULTS Here, we demonstrate how this bulk phenomenon affects secondary electron images that predominantly contain surface information. In addition, we will show how it can be used to obtain crystallographic information. We will discuss the origin of channeling contrast in secondary electron images, illustrate this with experiments, and develop a simple geometric model to predict channeling maxima. CONCLUSION Channeling plays an important role in helium ion microscopy and has to be taken into account when trying to achieve maximum image quality in backscattered helium images as well as secondary electron images. Secondary electron images can be used to extract crystallographic information from bulk samples as well as from thin surface layers, in a straightforward manner.
Collapse
Affiliation(s)
- Vasilisa Veligura
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Gregor Hlawacek
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Raoul van Gastel
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Harold J W Zandvliet
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| | - Bene Poelsema
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands
| |
Collapse
|
40
|
Marshall MM, Yang J, Hall AR. Direct and transmission milling of suspended silicon nitride membranes with a focused helium ion beam. SCANNING 2012; 34:101-106. [PMID: 22331671 DOI: 10.1002/sca.21003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Accepted: 10/20/2011] [Indexed: 05/31/2023]
Abstract
Helium ion milling of suspended silicon nitride thin films is explored. Milled squares patterned by scanning helium ion microscope are subsequently investigated by atomic force microscopy and the relation between ion dose and milling depth is measured for both the direct (side of ion incidence) and transmission (side opposite to ion incidence) regimes. We find that direct-milling depth varies linearly with beam dose while transmission-milling depth varies with the square of the beam dose, resulting in a straightforward method of controlling local film thickness.
Collapse
Affiliation(s)
- Michael M Marshall
- Joint School of Nanoscience and Nanoengineering, University of North Carolina Greensboro, Greensboro, North Carolina 27401, USA
| | | | | |
Collapse
|
41
|
Alkemade PFA, Koster EM, van Veldhoven E, Maas DJ. Imaging and nanofabrication with the helium ion microscope of the Van Leeuwenhoek Laboratory in Delft. SCANNING 2012; 34:90-100. [PMID: 22544486 DOI: 10.1002/sca.21009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Although helium ion microscopy (HIM) was introduced only a few years ago, many new application fields are emerging. The connecting factor between these novel applications is the unique interaction of the primary helium ion beam with the sample material at and just below its surface. In particular, the HIM secondary electron signal stems from an area that is extremely well localized around the point of incidence of the primary beam. This makes the HIM well suited for both high-resolution imaging and high-resolution nanofabrication. Another advantage in nanofabrication is the low ion backscattering fraction, which leads to a weak proximity effect. The subnanometer probe size and the unique beam-materials interactions have opened new areas of research. This review presents a selection of studies conducted on a single instrument. The selection encompasses applications ranging from imaging to nanofabrication and from fundamental academic research to applied industrial developments.
Collapse
Affiliation(s)
- Paul F A Alkemade
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
| | | | | | | |
Collapse
|
42
|
Winston D, Ferrera J, Battistella L, Vladár AE, Berggren KK. Modeling the point-spread function in helium-ion lithography. SCANNING 2012; 34:121-128. [PMID: 21938733 DOI: 10.1002/sca.20290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Accepted: 08/23/2011] [Indexed: 05/31/2023]
Abstract
We present here a hybrid approach to modeling helium-ion lithography that combines the power and ease-of-use of the Stopping and Range of Ions in Matter (SRIM) software with the results of recent work simulating secondary electron (SE) yield in helium-ion microscopy. This approach traces along SRIM-produced helium-ion trajectories, generating and simulating trajectories for SEs using a Monte Carlo method. We found, both through simulation and experiment, that the spatial distribution of energy deposition in a resist as a function of radial distance from beam incidence, i.e. the point spread function, is not simply a sum of Gauss functions.
Collapse
Affiliation(s)
- Donald Winston
- Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | | | | | | | | |
Collapse
|
43
|
Hill R, Notte JA, Scipioni L. Scanning Helium Ion Microscopy. ADVANCES IN IMAGING AND ELECTRON PHYSICS 2012. [DOI: 10.1016/b978-0-12-394396-5.00002-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
44
|
|
45
|
Non-monotonic material contrast in scanning ion and scanning electron images. Ultramicroscopy 2011; 111:1564-73. [PMID: 21939622 DOI: 10.1016/j.ultramic.2011.08.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 06/29/2011] [Accepted: 08/25/2011] [Indexed: 11/24/2022]
Abstract
30keV Ga(+) focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z(2), and shows a non-monotonic relationship between contrast and Z(2). The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion-solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z(2), following the periodic behavior of the stopping power for electron-solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle-solid interaction theory.
Collapse
|
46
|
Maas DJ, van der Drift EW, Veldhoven EV, Meessen J, Rudneva M, Alkemade PFA. Nano-engineering with a focused helium ion beam. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/opl.2011.1407] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTAlthough Helium Ion Microscopy (HIM) was introduced only a few years ago, many new application fields are budding. The connecting factor between these novel applications is the unique interaction of the primary helium ion beam with the sample material at and just below its surface. In particular, the HIM secondary electron (SE) signal stems from an area that is very well localized around the point of incidence of the primary beam. This makes the HIM well-suited for both high-resolution imaging as well as high resolution nanofabrication. Another advantage in nanofabrication is the low ion backscattering fraction, leading to a weak proximity effect. The lack of a quantitative materials analysis mode (like EDX in Scanning Electron Microscopy, SEM) and a relatively low beam current as compared to the SEM and the Gallium Focused Ion Beam are the present drawbacks of the HIM.
Collapse
|
47
|
Joy DC, Griffin BJ. Is microanalysis possible in the helium ion microscope? MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2011; 17:643-649. [PMID: 21736856 DOI: 10.1017/s1431927611000596] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Because the ability to perform some form of chemical microanalysis has become an essential feature for any microscope, it is necessary to investigate what options are available in the new "ORION" helium ion microscope (HIM). The HIM has the ability to visualize local variations in specimen chemistry in both the ion induced secondary electron and the Rutherford backscattered imaging modes, but this provides only limited and qualitative information. Quantitative, elementally specific, microanalysis could be performed in the HIM using secondary electron spectroscopy, Rutherford backscattered ion spectroscopy, or secondary ion mass spectroscopy, but while each of these options has promise, none of them can presently guarantee either reliable element identification or quantitative analysis across the periodic table.
Collapse
Affiliation(s)
- David C Joy
- Electron Microscopy Facility, University of Tennessee, Knoxville, TN 37996-0840, USA.
| | | |
Collapse
|
48
|
Castaldo V, Withagen J, Hagen C, Kruit P, van Veldhoven E. Angular dependence of the ion-induced secondary electron emission for He+ and Ga+ beams. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2011; 17:624-36. [PMID: 21676276 DOI: 10.1017/s1431927611000225] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In recent years, novel ion sources have been designed and developed that have enabled focused ion beam machines to go beyond their use as nano-fabrication tools. Secondary electrons are usually taken to form images, for their yield is high and strongly dependent on the surface characteristics, in terms of chemical composition and topography. In particular, the secondary electron yield varies characteristically with the angle formed by the beam and the direction normal to the sample surface in the point of impact. Knowledge of this dependence, for different ion/atom pairs, is thus the first step toward a complete understanding of the contrast mechanism in scanning ion microscopy. In this article, experimentally obtained ion-induced secondary electron yields as a function of the incidence angle of the beam on flat surfaces of Al and Cr are reported, for usual conditions in Ga+ and He+ microscopes. The curves have been compared with models and simulations, showing a good agreement for most of the angle range; deviations from the expected behavior are addressed and explanations are suggested. It appears that the maximum value of the ion-induced secondary electron yield is very similar in all the studied cases; the yield range, however, is consistently larger for helium than for gallium, which partially explains the enhanced topographical contrast of helium microscopes over the gallium focused ion beams.
Collapse
Affiliation(s)
- Vincenzo Castaldo
- Department of Applied Science, Delft University of Technology, Lorentzweg 1, Delft, Zuid-holland 2628CJ, The Netherlands.
| | | | | | | | | |
Collapse
|
49
|
Jepson M, Liu X, Bell D, Ferranti D, Inkson B, Rodenburg C. Resolution limits of secondary electron dopant contrast in helium ion and scanning electron microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2011; 17:637-642. [PMID: 21745435 DOI: 10.1017/s1431927611000365] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
As the miniaturization of semiconductor devices continues, characterization of dopant distribution within the structures becomes increasingly challenging. One potential solution is the use of the secondary electron signal produced in scanning electron (SEMs) or helium ion microscopes (HeIMs) to image the changes in electrical potential caused by the dopant atoms. In this article, the contrast mechanisms and resolution limits of secondary electron dopant contrast are explored. It is shown that the resolution of the technique is dependent on the extent of electrical potential present at a junction and that the resolution of dopant contrast can be improved in the HeIM after an in-situ plasma cleaning routine, which causes an oxide to form on the surface altering the contrast mechanism from electrical potential to material contrast.
Collapse
Affiliation(s)
- Mark Jepson
- Department of Materials, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
| | | | | | | | | | | |
Collapse
|
50
|
Castaldo V, Hagen C, Kruit P. Simulation of ion imaging: Sputtering, contrast, noise. Ultramicroscopy 2011; 111:982-94. [DOI: 10.1016/j.ultramic.2011.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 03/25/2011] [Accepted: 03/29/2011] [Indexed: 11/28/2022]
|