1
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Zaera F. The surface chemistry of the atomic layer deposition of metal thin films. NANOTECHNOLOGY 2024; 35:362001. [PMID: 38888294 DOI: 10.1088/1361-6528/ad54cb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 06/06/2024] [Indexed: 06/20/2024]
Abstract
In this perspective we discuss the progress made in the mechanistic studies of the surface chemistry associated with the atomic layer deposition (ALD) of metal films and the usefulness of that knowledge for the optimization of existing film growth processes and for the design of new ones. Our focus is on the deposition of late transition metals. We start by introducing some of the main surface-sensitive techniques and approaches used in this research. We comment on the general nature of the metallorganic complexes used as precursors for these depositions, and the uniqueness that solid surfaces and the absence of liquid solvents bring to the ALD chemistry and differentiate it from what is known from metalorganic chemistry in solution. We then delve into the adsorption and thermal chemistry of those precursors, highlighting the complex and stepwise nature of the decomposition of the organic ligands that usually ensued upon their thermal activation. We discuss the criteria relevant for the selection of co-reactants to be used on the second half of the ALD cycle, with emphasis on the redox chemistry often associated with the growth of metallic films starting from complexes with metal cations. Additional considerations include the nature of the substrate and the final structural and chemical properties of the growing films, which we indicate rarely retain the homogeneous 2D structure often aimed for. We end with some general conclusions and personal thoughts about the future of this field.
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Affiliation(s)
- Francisco Zaera
- Department of Chemistry, University of California, Riverside, CA 92521, United States of America
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2
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Dogan G, Demir SO, Gutzler R, Gruhn H, Dayan CB, Sanli UT, Silber C, Culha U, Sitti M, Schütz G, Grévent C, Keskinbora K. Bayesian Machine Learning for Efficient Minimization of Defects in ALD Passivation Layers. ACS APPLIED MATERIALS & INTERFACES 2021; 13:54503-54515. [PMID: 34735111 PMCID: PMC8603353 DOI: 10.1021/acsami.1c14586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Atomic layer deposition (ALD) is an enabling technology for encapsulating sensitive materials owing to its high-quality, conformal coating capability. Finding the optimum deposition parameters is vital to achieving defect-free layers; however, the high dimensionality of the parameter space makes a systematic study on the improvement of the protective properties of ALD films challenging. Machine-learning (ML) methods are gaining credibility in materials science applications by efficiently addressing these challenges and outperforming conventional techniques. Accordingly, this study reports the ML-based minimization of defects in an ALD-Al2O3 passivation layer for the corrosion protection of metallic copper using Bayesian optimization (BO). In all experiments, BO consistently minimizes the layer defect density by finding the optimum deposition parameters in less than three trials. Electrochemical tests show that the optimized layers have virtually zero film porosity and achieve five orders of magnitude reduction in corrosion current as compared to control samples. Optimized parameters of surface pretreatment using Ar/H2 plasma, the deposition temperature above 200 °C, and 60 ms pulse time quadruple the corrosion resistance. The significant optimization of ALD layers presented in this study demonstrates the effectiveness of BO and its potential outreach to a broader audience, focusing on different materials and processes in materials science applications.
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Affiliation(s)
- Gül Dogan
- Robert
Bosch GmbH, Automotive Electronics, Postfach 13 42, 72703 Reutlingen, Germany
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
| | - Sinan O. Demir
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
| | - Rico Gutzler
- Max
Planck Institute for Solid State Research, Heisenbergstr 1, 70569 Stuttgart, Germany
| | - Herbert Gruhn
- Robert
Bosch GmbH, Corporate Sector Research and Advance Engineering , Robert-Bosch-Campus1, 71272 Stuttgart, Germany
| | - Cem B. Dayan
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
| | - Umut T. Sanli
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
| | - Christian Silber
- Robert
Bosch GmbH, Automotive Electronics, Postfach 13 42, 72703 Reutlingen, Germany
| | - Utku Culha
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
| | - Metin Sitti
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
| | - Gisela Schütz
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
| | - Corinne Grévent
- Robert
Bosch GmbH, Automotive Electronics, Postfach 13 42, 72703 Reutlingen, Germany
| | - Kahraman Keskinbora
- Max
Planck Institute for Intelligent Systems, Heisenbergstr 3, 70569 Stuttgart, Germany
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3
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Fonseca J, Lu J. Single-Atom Catalysts Designed and Prepared by the Atomic Layer Deposition Technique. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01200] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Javier Fonseca
- Nanomaterial Laboratory for Catalysis and Advanced Separations, Department of Chemical Engineering, Northeastern University, 313 Snell Engineering Center, 360 Huntington Avenue, Boston, Massachusetts 02115-5000, United States
| | - Junling Lu
- Department of Chemical Physics, Hefei National Laboratory for Physical Sciences at the Microscale, iChEM, University of Science and Technology of China, Hefei, Anhui 230026, China
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4
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Zheng L, He W, Spampinato V, Franquet A, Sergeant S, Gendt SD, Armini S. Area-Selective Atomic Layer Deposition of TiN Using Trimethoxy(octadecyl)silane as a Passivation Layer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13144-13154. [PMID: 33104359 DOI: 10.1021/acs.langmuir.0c00741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Area-selective deposition (ASD) offers tremendous advantages when compared with conventional patterning processes, such as the possibility of achieving three-dimensional features in a bottom-up additive fashion. Recently, ASD is gaining more and more attention from IC manufacturers and equipment and material suppliers. Through combination of self-assembled monolayer (SAM) surface passivation of the nongrowth substrate area and atomic layer deposition (ALD) on the growth area, ASD selective to the growth area can be achieved. With the purpose of screening SAM precursors to provide optimal passivation performance on SiO2, various siloxane precursors with different terminal groups and alkyl chains were investigated. Additionally, the surface dependence and growth inhibition of TiN ALD on -NH2, -CF3, and -CH3 terminations is investigated. We demonstrated the methyl termination of the SAM precursor combined with a C18 alkyl chain plays an important role in broadening the ALD selectivity window by suppressing precursor adsorption. Owing to the high surface coverage, excellent thermal stability and longer carbon chain length, an optimized trimethoxy(octadecyl)silane (TMODS) film deposited from liquid phase was able to provide a selectivity higher than 0.99 up to 20 nm ALD film deposited on hydroxyl-terminated Si oxide. The approach followed in this work can allow extending the ASD process window, and it is relevant for a wide variety of applications.
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Affiliation(s)
- Li Zheng
- Interuniversity Microelectronics Centre, Kapeldreef 75, B-3001 Leuven, Belgium
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Wei He
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China
| | | | - Alexis Franquet
- Interuniversity Microelectronics Centre, Kapeldreef 75, B-3001 Leuven, Belgium
| | - Stefanie Sergeant
- Interuniversity Microelectronics Centre, Kapeldreef 75, B-3001 Leuven, Belgium
| | - Stefan De Gendt
- Interuniversity Microelectronics Centre, Kapeldreef 75, B-3001 Leuven, Belgium
| | - Silvia Armini
- Interuniversity Microelectronics Centre, Kapeldreef 75, B-3001 Leuven, Belgium
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5
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Ke W, Liu Y, Wang X, Qin X, Chen L, Palomino RM, Simonovis JP, Lee I, Waluyo I, Rodriguez JA, Frenkel AI, Liu P, Zaera F. Nucleation and Initial Stages of Growth during the Atomic Layer Deposition of Titanium Oxide on Mesoporous Silica. NANO LETTERS 2020; 20:6884-6890. [PMID: 32840377 DOI: 10.1021/acs.nanolett.0c02990] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A chemical approach to the deposition of thin films on solid surfaces is highly desirable but prone to affect the final properties of the film. To better understand the origin of these complications, the initial stages of the atomic layer deposition of titania films on silica mesoporous materials were characterized. Adsorption-desorption measurements indicated that the films grow in a layer-by-layer fashion, as desired, but initially exhibit surprisingly low densities, about one-quarter of that of bulk titanium oxide. Electron microscopy, X-ray diffraction, UV/visible, and X-ray absorption spectroscopy data pointed to the amorphous nature of the first monolayers, and EXAFS and 29Si CP/MAS NMR results to an initial growth via the formation of individual tetrahedral Ti-oxide units on isolated Si-OH surface groups with unusually long Ti-O bonds. Density functional theory calculations were used to propose a mechanism where the film growth starts at the nucleation centers to form an open 2D structure.
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Affiliation(s)
- Wang Ke
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Yang Liu
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Xuelong Wang
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Xiangdong Qin
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Limei Chen
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Robert M Palomino
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Juan Pablo Simonovis
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Ilkeun Lee
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Iradwikanari Waluyo
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - José A Rodriguez
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Anatoly I Frenkel
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Ping Liu
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
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6
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Dogan G, Sanli UT, Hahn K, Müller L, Gruhn H, Silber C, Schütz G, Grévent C, Keskinbora K. In Situ X-ray Diffraction and Spectro-Microscopic Study of ALD Protected Copper Films. ACS APPLIED MATERIALS & INTERFACES 2020; 12:33377-33385. [PMID: 32551474 DOI: 10.1021/acsami.0c06873] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In many applications of copper in industry and research, copper migration and degradation of metallic copper to its oxides is a common problem. There are numerous ways to overcome this degradation with varying success. Atomic layer deposition (ALD) based encapsulation and passivation of the metallic copper recently emerged as a serious route to success owing to the conformality and density of the ALD films. So far, the majority of the studies have been focused on corrosion protection of copper in a variety of chemical environments, mostly at ambient temperature. An investigation of the stability of the ALD film stacks and copper's interaction with them at elevated temperatures has been lacking. Here, we study the mitigation of copper oxidation and migration in 50 nm thick Al2O3/TiO2 and Al2O3/SiO2 bilayer ALD stacks. First, the corrosion dynamics were investigated via in situ X-ray diffraction (XRD) at 350 °C under atmospheric conditions, and second, the interaction of copper with the passivation layers have been examined post factum using detailed spectro-microscopic investigations. According to the XRD results, both ALD films exhibited excellent oxidation protection. In contrast, bare Cu immediately started to oxidize at 350 °C and transformed entirely to its known oxide phases in 4 h. Spectro-microscopic studies revealed that there are structural and chemical changes on the top surface and within the film stacks. The TiO2 layer was crystallized during annealing, while the SiO2 layer stayed in the amorphous phase, which was analyzed by grazing incidence XRD and transmission electron microscopy. According to scanning electron microscopy and X-ray photoelectron spectroscopy analysis, copper was detected on the surface with a higher amount in Al2O3/TiO2 than Al2O3/SiO2, 5.2 at.% and 0.7 at.%, respectively. Based on the surface and cross-sectional analysis, copper migration was observed on both layers, albeit more substantially in Al2O3/TiO2. In the case of Al2O3/SiO2, the bulk of the copper was captured at the interface of the two oxides.
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Affiliation(s)
- Gül Dogan
- Robert Bosch GmbH, Automotive Electronics, Postfach 13 42, 72703 Reutlingen, Germany
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany
| | - Umut T Sanli
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany
| | - Kersten Hahn
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Lutz Müller
- Robert Bosch GmbH, Automotive Electronics, Postfach 13 42, 72703 Reutlingen, Germany
| | - Herbert Gruhn
- Robert Bosch GmbH, Corporate Sector Research and Advance Engineering, Robert-Bosch-Campus1, 71272 Stuttgart, Germany
| | - Christian Silber
- Robert Bosch GmbH, Automotive Electronics, Postfach 13 42, 72703 Reutlingen, Germany
| | - Gisela Schütz
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany
| | - Corinne Grévent
- Robert Bosch GmbH, Automotive Electronics, Postfach 13 42, 72703 Reutlingen, Germany
| | - Kahraman Keskinbora
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany
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7
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Konh M, Lien C, Cai X, Wei SH, Janotti A, Zaera F, Teplyakov AV. ToF-SIMS Investigation of the Initial Stages of MeCpPt(CH 3) 3 Adsorption and Decomposition on Nickel Oxide Surfaces: Exploring the Role and Location of the Ligands. Organometallics 2020. [DOI: 10.1021/acs.organomet.9b00781] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mahsa Konh
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Clinton Lien
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Xuefen Cai
- Material Science and Engineering Department, University of Delaware, Newark, Delaware 19716, United States
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Su-Huai Wei
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Anderson Janotti
- Material Science and Engineering Department, University of Delaware, Newark, Delaware 19716, United States
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Andrew V. Teplyakov
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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8
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Chavan RD, Tavakoli MM, Prochowicz D, Yadav P, Lote SS, Bhoite SP, Nimbalkar A, Hong CK. Atomic Layer Deposition of an Effective Interface Layer of TiN for Efficient and Hysteresis-Free Mesoscopic Perovskite Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2020; 12:8098-8106. [PMID: 31994862 DOI: 10.1021/acsami.9b18082] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Perovskite solar cells (PSCs) have experienced outstanding advances in power conversion efficiencies (PCEs) by employing new electron transport layers (ETLs), interface engineering, optimizing perovskite morphology, and improving charge collection efficiency. In this work, we study the role of a new ultrathin interface layer of titanium nitride (TiN) conformally deposited on a mesoporous TiO2 (mp-TiO2) scaffold using the atomic layer deposition method. Our characterization results revealed that the presence of TiN at the ETL/perovskite interface improves the charge collection as well as reduces the interface recombination. We find that the morphology (grain size) and optical properties of the perovskite film deposited on the optimized mp-TiO2/TiN ETL are improved drastically, leading to devices with a maximum PCE of 19.38% and a high open-circuit voltage (Voc) of 1.148 V with negligible hysteresis and improved environmental (∼40% RH) and thermal (80 °C) stabilities.
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Affiliation(s)
- Rohit D Chavan
- Polymer Energy Materials Laboratory, School of Applied Chemical Engineering , Chonnam National University , Gwangju 61186 , South Korea
| | - Mohammad Mahdi Tavakoli
- Department of Electrical Engineering and Computer Science , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
- Department of Materials Science and Engineering , Sharif University of Technology , Tehran 14588 , Iran
| | - Daniel Prochowicz
- Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , Warsaw 01-224 , Poland
| | - Pankaj Yadav
- Department of Solar Energy, School of Technology , Pandit Deendayal Petroleum University , Gandhinagar 382 007 , Gujarat , India
| | - Shivani S Lote
- Polymer Energy Materials Laboratory, School of Applied Chemical Engineering , Chonnam National University , Gwangju 61186 , South Korea
| | - Sangram P Bhoite
- Polymer Energy Materials Laboratory, School of Applied Chemical Engineering , Chonnam National University , Gwangju 61186 , South Korea
| | - Ajaysing Nimbalkar
- Polymer Energy Materials Laboratory, School of Applied Chemical Engineering , Chonnam National University , Gwangju 61186 , South Korea
| | - Chang Kook Hong
- Polymer Energy Materials Laboratory, School of Applied Chemical Engineering , Chonnam National University , Gwangju 61186 , South Korea
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9
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Lee I, Zaera F. Use of Au@Void@TiO 2 yolk-shell nanostructures to probe the influence of oxide crystallinity on catalytic activity for low-temperature oxidations. J Chem Phys 2019; 151:234706. [DOI: 10.1063/1.5132715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ilkeun Lee
- Department of Chemistry and UCR Center for Catalysis, University of California, Riverside, California 92521, USA
| | - Francisco Zaera
- Department of Chemistry and UCR Center for Catalysis, University of California, Riverside, California 92521, USA
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10
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Chen B, Qin X, Lien C, Bouman M, Konh M, Duan Y, Teplyakov AV, Zaera F. Thermal Chemistry of Metal Organic Compounds Adsorbed on Oxide Surfaces. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00636] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bo Chen
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Xiangdong Qin
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Clinton Lien
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Menno Bouman
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Mahsa Konh
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Yichen Duan
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Andrew V. Teplyakov
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
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11
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Lien C, Konh M, Chen B, Teplyakov AV, Zaera F. Gas-Phase Electron-Impact Activation of Atomic Layer Deposition (ALD) Precursors: MeCpPtMe 3. J Phys Chem Lett 2018; 9:4602-4606. [PMID: 30067025 DOI: 10.1021/acs.jpclett.8b02125] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The use of gas-phase electron-impact activation of metalorganic complexes to facilitate atomic layer depositions (ALD) was tested for the case of (methylcyclopentadienyl)Pt(IV) trimethyl (MeCpPtMe3) on silicon oxide films. Uptake enhancements of more than 1 order of magnitude were calculated from X-ray photoelectron spectroscopy (XPS) data. On the basis of the measured C:Pt ratios, the surface species were estimated to mainly consist of MeCpPt moieties, likely because of the prevalent formation of [MeCpPtMe x- nH]+ ions after gas-phase ionization (as determined by mass spectrometry). Counterintuitively, more extensive adsorption was observed on thick SiO2 films than on the native thin SiO2 film that forms on Si(100) wafers, despite the former having virtually no surface OH groups. The adsorption of MeCpPt fragments on silicon oxide surfaces was determined by density functional theory (DFT) calculations to be highly exothermic and to favor attachment to Si-O-Si bridge sites.
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Affiliation(s)
- Clinton Lien
- Department of Chemistry , University of California , Riverside , California 02521 , United States
| | - Mahsa Konh
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Bo Chen
- Department of Chemistry , University of California , Riverside , California 02521 , United States
| | - Andrew V Teplyakov
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Francisco Zaera
- Department of Chemistry , University of California , Riverside , California 02521 , United States
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12
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Barry ST, Teplyakov AV, Zaera F. The Chemistry of Inorganic Precursors during the Chemical Deposition of Films on Solid Surfaces. Acc Chem Res 2018; 51:800-809. [PMID: 29489341 DOI: 10.1021/acs.accounts.8b00012] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The deposition of thin solid films is central to many industrial applications, and chemical vapor deposition (CVD) methods are particularly useful for this task. For one, the isotropic nature of the adsorption of chemical species affords even coverages on surfaces with rough topographies, an increasingly common requirement in microelectronics. Furthermore, by splitting the overall film-depositing reactions into two or more complementary and self-limiting steps, as it is done in atomic layer depositions (ALD), film thicknesses can be controlled down to the sub-monolayer level. Thanks to the availability of a vast array of inorganic and metalorganic precursors, CVD and ALD are quite versatile and can be engineered to deposit virtually any type of solid material. On the negative side, the surface chemistry that takes place in these processes is often complex, and can include undesirable side reactions leading to the incorporation of impurities in the growing films. Appropriate precursors and deposition conditions need to be chosen to minimize these problems, and that requires a proper understanding of the underlying surface chemistry. The precursors for CVD and ALD are often designed and chosen based on their known thermal chemistry from inorganic chemistry studies, taking advantage of the vast knowledge developed in that field over the years. Although a good first approximation, however, this approach can lead to wrong choices, because the reactions of these precursors at gas-solid interfaces can be quite different from what is seen in solution. For one, solvents often aid in the displacement of ligands in metalorganic compounds, providing the right dielectric environment, temporarily coordinating to the metal, or facilitating multiple ligand-complex interactions to increase reaction probabilities; these options are not available in the gas-solid reactions associated with CVD and ALD. Moreover, solid surfaces act as unique "ligands", if these reactions are to be viewed from the point of view of the metalorganic complexes used as precursors: they are bulky and rigid, can provide multiple binding sites for a single reaction, and can promote unique bonding modes, especially on metals, which have delocalized electronic structures. The differences between the molecular and surface chemistry of CVD and ALD precursors can result in significant variations in their reactivity, ultimately leading to unpredictable properties in the newly grown films. In this Account, we discuss some of the main similarities and differences in chemistry that CVD/ALD precursors follow on surfaces when contrasted against their known behavior in solution, with emphasis on our own work but also referencing other key contributions. Our approach is unique in that it combines expertise from the inorganic, surface science, and quantum-mechanics fields to better understand the mechanistic details of the chemistry of CVD and ALD processes and to identify new criteria to consider when designing CVD/ALD precursors.
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Affiliation(s)
- Seán T. Barry
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Andrew V. Teplyakov
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
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13
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O’Neill BJ, Jackson DHK, Lee J, Canlas C, Stair PC, Marshall CL, Elam JW, Kuech TF, Dumesic JA, Huber GW. Catalyst Design with Atomic Layer Deposition. ACS Catal 2015. [DOI: 10.1021/cs501862h] [Citation(s) in RCA: 514] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | | | | | | | - Peter C. Stair
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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14
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Fiorentino G, Vollebregt S, Tichelaar FD, Ishihara R, Sarro PM. Impact of the atomic layer deposition precursors diffusion on solid-state carbon nanotube based supercapacitors performances. NANOTECHNOLOGY 2015; 26:064002. [PMID: 25604841 DOI: 10.1088/0957-4484/26/6/064002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A study on the impact of atomic layer deposition (ALD) precursors diffusion on the performance of solid-state miniaturized nanostructure capacitor array is presented. Three-dimensional nanostructured capacitor array based on double conformal coating of multiwalled carbon nanotubes (MWCNTs) bundles is realized using ALD to deposit Al2O3 as dielectric layer and TiN as high aspect-ratio conformal counter-electrode on 2 μm long MWCNT bundles. The devices have a small footprint (from 100 μm(2) to 2500 μm(2)) and are realized using an IC wafer-scale manufacturing process with high reproducibility (≤0.3E-12F deviation). To evaluate the enhancement of the electrode surface, the measured capacitance values are compared to a lumped circuital model. The observed discrepancies are explained with a partial coating of the CNT, that determine a limited use of the available electrode surface area. To analyze the CNT coating effectiveness, the ALD precursors diffusions inside the CNT bundle is studied using a Knudsen diffusion mechanism.
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Affiliation(s)
- Giuseppe Fiorentino
- Delft University of Technology, Delft Institute of Microsystems and Nanotechnology, Faculty of Electrical Engineering, Mathematics and Computers Science, Laboratory of Electronic Components, Technology and Materials, Feldmannweg 17, 2628 CT Delft, The Netherlands
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15
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Bouman M, Qin X, Doan V, Groven BLD, Zaera F. Reaction of Methylcyclopentadienyl Manganese Tricarbonyl on Silicon Oxide Surfaces: Implications for Thin Film Atomic Layer Depositions. Organometallics 2014. [DOI: 10.1021/om5006269] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Menno Bouman
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Xiangdong Qin
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Vananh Doan
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Benjamin L. D. Groven
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
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16
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Chang YM, Ravipati S, Kao PH, Shieh J, Ko FH, Juang JY. Broadband antireflection and field emission properties of TiN-coated Si-nanopillars. NANOSCALE 2014; 6:9846-9851. [PMID: 25029029 DOI: 10.1039/c4nr01874e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Broadband antireflection and field emission characteristics of silicon nanopillars (Si-NPs) fabricated by self-masking dry etching in hydrogen-containing plasma were systematically investigated. In particular, the effects of ultrathin (5-20 nm) titanium nitride (TiN) films deposited on Si-NPs by atomic layer deposition (ALD) on the optoelectronic properties were explored. The results showed that by coating the Si-NPs with a thin layer of TiN the antireflection capability of pristine Si-NPs can be significantly improved, especially in the wavelength range of 1000-1500 nm. The enhanced field emission characteristics of these TiN/Si-NP heterostructures suggest that, in addition to the reflectance suppression in the long wavelength range arising from the strong wavelength-dependent refractive index of TiN, the TiN-coating may have also significantly modified the effective work function at the TiN/Si interface as well.
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Affiliation(s)
- Yuan-Ming Chang
- Department of Electrophysics, National Chiao Tung University, Hsinchu 300, Taiwan.
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17
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Zaera F. Mechanisms of surface reactions in thin solid film chemical deposition processes. Coord Chem Rev 2013. [DOI: 10.1016/j.ccr.2013.04.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Li WM. Recent Developments of Atomic Layer Deposition Processes for Metallization. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/cvde.201300052] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Sun H, Qin X, Zaera F. Activation of Metal-Organic Precursors by Electron Bombardment in the Gas Phase for Enhanced Deposition of Solid Films. J Phys Chem Lett 2012; 3:2523-2527. [PMID: 26292144 DOI: 10.1021/jz3011332] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The incorporation of gas-phase electron-impact ionization and activation of metal-organic compounds into atomic layer deposition (ALD) processes is reported as a way to enhance film growth with stable precursors. Specifically, it is shown here that gas-phase activation of methylcyclopentadienylmanganese tricarbonyl, MeCpMn(CO)3, which was accomplished by using a typical nude ion gauge employed in many ultrahigh-vacuum (UHV) studies, enhances its dissociative adsorption on silicon surfaces, affording the design of ALD cycles with more extensive Mn deposition and at lower temperatures. Significantly higher Mn uptakes were demonstrated by X-ray photoelectron spectroscopy (XPS) on both silicon dioxide films and on Si(100) wafers Ar(+)-sputtered to remove their native oxide layer. The effectiveness of this electron-impact activation approach in ALD is explained in terms of the cracking patterns seen in mass spectrometry for the metal-organic precursor used.
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Affiliation(s)
- Huaxing Sun
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Xiangdong Qin
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
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20
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Ishchuk S, Taffa DH, Hazut O, Kaynan N, Yerushalmi R. Transformation of organic-inorganic hybrid films obtained by molecular layer deposition to photocatalytic layers with enhanced activity. ACS NANO 2012; 6:7263-9. [PMID: 22768917 DOI: 10.1021/nn302370y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present the transformation of organic-inorganic hybrid titanicone films formed by TiCl(4) as metal precursor and ethylene glycol (EG) using solvent-free MLD to highly active photocatalytic films. The photocatalytic activities of the films were investigated using hydroxyl-functionalized porphyrin as a spectroscopic marker. TEM imaging and electron diffraction, XPS, UV-vis spectroscopy, and spectroscsopic ellipsometry were employed for structural and composition analyses of the films. The photocatalytic activity of Ti-EG films was investigated for different anneal temperatures and compared to TiO(2) films prepared by ALD using TiCl(4) as metal precursor and H(2)O (TiO(2) films). Overall, our results indicate that the photocatalytic activity of the thermally annealed Ti-EG film is about 5-fold increased compared to that of the TiO(2) film prepared by ALD for optimal process conditions. The combined results indicate that the structural and photocatalytic properties can be assigned to three states: (I) amorphous state, intermediate dye loading, low photocatalytic activity, (II) intermediate film state with both crystalline and amorphous regions, high dye loading, high catalytic activity, and (III) highly crystalline film with low dye loading and low photocatalytic activity. The formation of photocatalytic nanotubes (NTs) is demonstrated using sacrificial Ge nanowires (NWs) scaffolds to yield Ti-EG NT structures with controllable wall thickness structures and enhanced dye loading capacity. Our results demonstrate the feasibility and high potential of MLD to form metal oxides with high photocatalytic activity.
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Affiliation(s)
- Sergey Ishchuk
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J Safra Campus, Givat Ram Jerusalem, 91904, Israel
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21
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Zaera F. The Surface Chemistry of Atomic Layer Depositions of Solid Thin Films. J Phys Chem Lett 2012; 3:1301-1309. [PMID: 26286774 DOI: 10.1021/jz300125f] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Atomic layer deposition (ALD) is one of the most promising methodologies available for the growth of solid thin films conformally on complex topographies and with atomic-level control on thickness. However, as a chemical process, ALD can lead to the incorporation of impurities and to the growth of poor-quality films. Here we discuss some possible complications associated with the chemistry of ALD, including its ill-defined stoichiometry, the stepwise and extensive surface conversion possible with the ligands of most ALD metalorganic precursors, the need for the reduction or oxidation of the deposited elements, the poor understanding of the role of the coreactants, the dominant activity of specific minority surface sites in starting ALD processes, and the development of complex layered or three-dimensional structures within the deposited films. The resolution of these issues should help with the development of a more systematic approach for the selection of ALD precursors and for the design of ALD processes.
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Affiliation(s)
- Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
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22
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Guo S, Ghazinejad M, Qin X, Sun H, Wang W, Zaera F, Ozkan M, Ozkan CS. Tuning electron transport in graphene-based field-effect devices using block co-polymers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:1073-1080. [PMID: 22331656 DOI: 10.1002/smll.201101611] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 09/21/2011] [Indexed: 05/31/2023]
Abstract
Graphene possesses many remarkable properties and shows promise as the future material for building nanoelectronic devices. For many applications such as graphene-based field-effect transistors (GFET), it is essential to control or modulate the electronic properties by means of doping. Using spatially controlled plasma-assisted CF(4) doping, the Dirac point shift of a GFET covered with a polycrystalline PS-P4VP block co-polymer (BCP) [poly(styrene-b-4-vinylpyridine)] having a cylindrical morphology can be controlled. By changing the chemical component of the microdomain (P4VP) and the major domain (PS) with the CF(4) plasma technique, the doping effect is demonstrated. This work provides a methodology where the Dirac point can be controlled via the different sensitivities of the PS and P4VP components of the BCP subjected to plasma processing.
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Affiliation(s)
- Shirui Guo
- Department of Chemistry, University of California, Riverside 92521, USA
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23
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Lee HBR, Park YJ, Baik S, Kim H. Initial Stage Growth during Plasma-Enhanced Atomic Layer Deposition of Cobalt. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/cvde.201106937] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Kan BC, Boo JH, Lee I, Zaera F. Thermal Chemistry of Tetrakis(ethylmethylamido)titanium on Si(100) Surfaces. J Phys Chem A 2009; 113:3946-54. [DOI: 10.1021/jp8102172] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Byung-Chang Kan
- Department of Chemistry, University of California, Riverside, California 92521
| | - Jin-Hyo Boo
- Department of Chemistry, University of California, Riverside, California 92521
| | - Ilkeun Lee
- Department of Chemistry, University of California, Riverside, California 92521
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521
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25
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WATANABE R, IYODA T, ITO K. Nanostructured Titanium Oxide Fabricated via Block Copolymer Template. ELECTROCHEMISTRY 2009. [DOI: 10.5796/electrochemistry.77.214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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26
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Synthesis of heterogeneous catalysts with well shaped platinum particles to control reaction selectivity. Proc Natl Acad Sci U S A 2008; 105:15241-6. [PMID: 18832170 DOI: 10.1073/pnas.0805691105] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Colloidal and sol-gel procedures have been used to prepare heterogeneous catalysts consisting of platinum metal particles with narrow size distributions and well defined shapes dispersed on high-surface-area silica supports. The overall procedure was developed in three stages. First, tetrahedral and cubic colloidal metal particles were prepared in solution by using a procedure derived from that reported by El-Sayed and coworkers [Ahmadi TS, Wang ZL, Green TC, Henglein A, El-Sayed MA (1996) Science 272:1924-1926]. This method allowed size and shape to be controlled independently. Next, the colloidal particles were dispersed onto high-surface-area solids. Three approaches were attempted: (i) in situ reduction of the colloidal mixture in the presence of the support, (ii) in situ sol-gel synthesis of the support in the presence of the colloidal particles, and (iii) direct impregnation of the particles onto the support. Finally, the resulting catalysts were activated and tested for the promotion of carbon-carbon double-bond cis-trans isomerization reactions in olefins. Our results indicate that the selectivity of the reaction may be controlled by using supported catalysts with appropriate metal particle shapes.
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27
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Tiznado H, Bouman M, Kang BC, Lee I, Zaera F. Mechanistic details of atomic layer deposition (ALD) processes for metal nitride film growth. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.molcata.2007.06.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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Zaera F. The surface chemistry of thin film atomic layer deposition (ALD) processes for electronic device manufacturing. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b803832e] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Huang TT, Tan K, Lin MH, Zhang QE. CVD Reactions of TiCl4 with Ammonia: a Quantum Chemical Study. CHINESE J CHEM 2007. [DOI: 10.1002/cjoc.200790176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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