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Jiang W, Zhu L, Chen L, Yang Y, Yu X, Li X, Mu Z, Yu W. In Situ Synchrotron XRD Characterization of Piezoelectric Al 1-xSc xN Thin Films for MEMS Applications. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1781. [PMID: 36902897 PMCID: PMC10004546 DOI: 10.3390/ma16051781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/18/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Aluminum scandium nitride (Al1-xScxN) film has drawn considerable attention owing to its enhanced piezoelectric response for micro-electromechanical system (MEMS) applications. Understanding the fundamentals of piezoelectricity would require a precise characterization of the piezoelectric coefficient, which is also crucial for MEMS device design. In this study, we proposed an in situ method based on a synchrotron X-ray diffraction (XRD) system to characterize the longitudinal piezoelectric constant d33 of Al1-xScxN film. The measurement results quantitatively demonstrated the piezoelectric effect of Al1-xScxN films by lattice spacing variation upon applied external voltage. The as-extracted d33 had a reasonable accuracy compared with the conventional high over-tone bulk acoustic resonators (HBAR) devices and Berlincourt methods. It was also found that the substrate clamping effect, leading to underestimation of d33 from in situ synchrotron XRD measurement while overestimation using Berlincourt method, should be thoroughly corrected in the data extraction process. The d33 of AlN and Al0.9Sc0.1N obtained by synchronous XRD method were 4.76 pC/N and 7.79 pC/N, respectively, matching well with traditional HBAR and Berlincourt methods. Our findings prove the in situ synchrotron XRD measurement as an effective method for precise piezoelectric coefficient d33 characterization.
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Affiliation(s)
- Wenzheng Jiang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Zhu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lingli Chen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yumeng Yang
- Shanghai Engineering Research Center of Energy Efficient and Custom AI IC, School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xi Yu
- School of Microelectronics, Shanghai University, Shanghai 200444, China
| | - Xiaolong Li
- Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China
| | - Zhiqiang Mu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenjie Yu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
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Zhang H, Wang Y, Wang L, Liu Y, Chen H, Wu Z. Process Control Monitor (PCM) for Simultaneous Determination of the Piezoelectric Coefficients d31 and d33 of AlN and AlScN Thin Films. MICROMACHINES 2022; 13:mi13040581. [PMID: 35457885 PMCID: PMC9030765 DOI: 10.3390/mi13040581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/02/2022] [Accepted: 04/05/2022] [Indexed: 12/02/2022]
Abstract
Accurate and efficient measurements of the piezoelectric properties of AlN and AlScN films are very important for the design and simulation of micro-electro-mechanical system (MEMS) sensors and actuator devices. In this study, a process control monitor (PCM) structure compatible with the device manufacturing process is designed to achieve accurate determination of the piezoelectric coefficients of MEMS devices. Double-beam laser interferometry (DBLI) and laser Doppler vibrometry (LDV) measurements are applied and combined with finite element method (FEM) simulations, and values of the piezoelectric parameters d33 and d31 are simultaneously extracted. The accuracy of d31 is verified directly by using a cantilever structure, and the accuracy of d33 is verified by in situ synchrotron radiation X-ray diffraction; the comparisons confirm the viability of the results obtained by the novel combination of LDV, DBLI and FEM techniques in this study.
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Affiliation(s)
- Hao Zhang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (H.Z.); (Y.W.); (L.W.); (Y.L.); (H.C.)
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Wang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (H.Z.); (Y.W.); (L.W.); (Y.L.); (H.C.)
| | - Lihao Wang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (H.Z.); (Y.W.); (L.W.); (Y.L.); (H.C.)
| | - Yichen Liu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (H.Z.); (Y.W.); (L.W.); (Y.L.); (H.C.)
| | - Hao Chen
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (H.Z.); (Y.W.); (L.W.); (Y.L.); (H.C.)
| | - Zhenyu Wu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (H.Z.); (Y.W.); (L.W.); (Y.L.); (H.C.)
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing 100049, China
- Shanghai Industrial μTechnology Research Institute, Shanghai 201800, China
- School of Microelectronics, Shanghai University, Shanghai 200444, China
- Correspondence: ; Tel.: +86-21-6251-1070
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Wu D, Chen Y, Manna S, Talley K, Zakutayev A, Brennecka GL, Ciobanu CV, Constantine P, Packard CE. Characterization of Elastic Modulus Across the (Al 1-xSc x)N System Using DFT and Substrate-Effect-Corrected Nanoindentation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:2167-2175. [PMID: 30113894 DOI: 10.1109/tuffc.2018.2862240] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Knowledge of accurate values of elastic modulus of (Al1-xScx)N is required for design of piezoelectric resonators and related devices. Thin films of (Al1-xScx)N across the entire composition space are deposited and characterized. Accuracy of modulus measurements is improved and quantified by removing the influence of substrate effects and by direct comparison of experimental results with density functional theory calculations. The 5%-30% Sc compositional range is of particular interest for piezoelectric applications and is covered at higher compositional resolution here than in previous work. The reduced elastic modulus is found to decrease by as much as 40% with increasing Sc concentration in the wurtzite phase according to both experimental and computational techniques, whereas Sc-rich rocksalt-structured films exhibit little variation in modulus with composition.
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Caro MA, Zhang S, Riekkinen T, Ylilammi M, Moram MA, Lopez-Acevedo O, Molarius J, Laurila T. Piezoelectric coefficients and spontaneous polarization of ScAlN. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:245901. [PMID: 26000892 DOI: 10.1088/0953-8984/27/24/245901] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a computational study of spontaneous polarization and piezoelectricity in Sc(x)Al(1-x)N alloys in the compositional range from x = 0 to x = 0.5, obtained in the context of density functional theory and the Berry-phase theory of electric polarization using large periodic supercells. We report composition-dependent values of piezoelectric coefficients e(ij), piezoelectric moduli d(ij) and elastic constants C(ij). The theoretical findings are complemented with experimental measurement of e33 for a series of sputtered ScAlN films carried out with a piezoelectric resonator. The rapid increase with Sc content of the piezoelectric response reported in previous studies is confirmed for the available data. A detailed description of the full methodology required to calculate the piezoelectric properties of ScAlN, with application to other complex alloys, is presented. In particular, we find that the large amount of internal strain present in ScAlN and its intricate relation with electric polarization make configurational sampling and the use of large supercells at different compositions necessary in order to accurately derive the piezoelectric response of the material.
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Affiliation(s)
- Miguel A Caro
- Department of Electrical Engineering and Automation, Aalto University, 02150 Espoo, Finland. COMP Centre of Excellence in Computational Nanoscience, Department of Applied Physics, Aalto University, 02150 Espoo, Finland
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