电子辐照对4H-SiC MOS材料缺陷的影响

人工晶体学报 ›› 2024, Vol. 53 ›› Issue (9): 1536-1541.

电子辐照对4H-SiC MOS材料缺陷的影响

刘帅^1,2, 熊慧凡^1,2, 杨霞^2,3, 杨德仁^1,2, 皮孝东^1,2, 宋立辉^1,2

1.浙江大学材料科学与工程学院,硅及先进半导体材料全国重点实验室,杭州 310027;
2.浙江大学杭州国际科创中心,先进半导体研究院和浙江省宽禁带功率半导体材料与器件重点实验室,杭州 311200;
3.杭州电子科技大学材料与环境工程学院,杭州 310018

收稿日期:2024-03-12 出版日期:2024-09-15 发布日期:2024-09-19
通信作者: 皮孝东,博士,教授。E-mail:xdpi@zju.edu.cn; 宋立辉,博士,研究员。E-mail:songlihui@zju.edu.cn
作者简介:刘帅(1990—),女,安徽省人,博士。E-mail:0622478@zju.edu.cn
基金资助:
浙江大学杭州国际科创中心人才专项

Effects of Electron Irradiation on Defects of 4H-SiC MOS Materials

LIU Shuai^1,2, XIONG Huifan^1,2, YANG Xia^2,3, YANG Deren^1,2, PI Xiaodong^1,2, SONG Lihui^1,2

1. State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China;
2. Institute of Advanced Semiconductors & Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China;
3. College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China

Received:2024-03-12 Online:2024-09-15 Published:2024-09-19

摘要/Abstract

摘要： 4H-SiC金属氧化物半导体(MOS)基器件在电子辐照环境下应用时可能产生新的材料缺陷,导致其电学性能发生退化。本文选取结构最简单的MOS基器件(4H-SiC MOS电容器)为对象,研究了一系列电子辐照剂量下材料缺陷的演变情况。在10 MeV电子束下对MOS样品进行30、50、100、500、1 000 kGy剂量的辐照,对辐照前、后样品进行深能级瞬态谱测试(DLTS)和电容-电压(C-V)曲线表征。DLTS实验结果表明,低剂量电子辐照前、后4H-SiC/SiO₂界面及近界面处的缺陷没有发生明显变化,而高剂量辐照导致双碳间隙原子缺陷的构型发生了改变,演变后的构型能级位置更深,化学结构更加稳定。C-V曲线测试结果发现,不同电子辐照剂量导致MOS电容器平带电压发生不同程度的负向漂移,这很可能是SiO₂氧化层中氧空位数量和4H-SiC/SiO₂界面及近界面处缺陷数量共同影响的结果。本文研究结果对研发和优化抗电子辐照的4H-SiC MOS制备工艺具有一定的参考价值。

关键词: 4H-SiC MOS, 电子辐照, 缺陷变化, 双碳间隙原子, 深能级瞬态谱

Abstract: 4H-SiC metal-oxide-semiconductor (MOS)-based devices appear to worse electrical performance when exposed to electron irradiation, owing to the production of material defects. This study demonstrates an analysis of defect evolution of 4H-SiC MOS capacitors with the simplest structure, subjected to a series dose of electron irradiation with 10 MeV electron beam, including 30, 50, 100, 500, 1 000 kGy. Deep level transient spectroscopy (DLTS) test and capacitance-voltage (C-V) measurement were used to obtain defects information among MOS samples pre- and post-irradiation. DLTS results present that a low dose of irradiation causes no evident impact on defect evolution near and at the 4H-SiC/SiO₂ interface, whereas a high dose of irradiation makes a defect configuration of carbon interstitial dimer defect evolve into another more stable one at a deeper energy level. C-V curves show that different irradiation doses lead to different negative shift degrees of flat-band voltage. This is considered to be resulted from multiple factors, including oxygen vacancies in the SiO₂ layer and defects near and at the 4H-SiC/SiO₂ interface. This work might be helpful for the development and optimization of 4H-SiC MOS fabrication with respect to anti-irradiation performance.

Key words: 4H-SiC MOS, electron irradiation, defect evolution, carbon interstitial dimer, deep level transient spectroscopy

中图分类号:

TN386.1

刘帅, 熊慧凡, 杨霞, 杨德仁, 皮孝东, 宋立辉. 电子辐照对4H-SiC MOS材料缺陷的影响[J]. 人工晶体学报, 2024, 53(9): 1536-1541.

LIU Shuai, XIONG Huifan, YANG Xia, YANG Deren, PI Xiaodong, SONG Lihui. Effects of Electron Irradiation on Defects of 4H-SiC MOS Materials[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(9): 1536-1541.

参考文献

[1] LIU G, TUTTLE B R, DHAR S. Silicon carbide: a unique platform for metal-oxide-semiconductor physics[J]. Applied Physics Reviews, 2015, 2(2): 021307.
[2] LELIS A J, GREEN R, HABERSAT D B, et al. Basic mechanisms of threshold-voltage instability and implications for reliability testing of SiC MOSFETs[J]. IEEE Transactions on Electron Devices, 2015, 62(2): 316-323.
[3] KAWAHARA K, JUN S D, KIMOTO T. Deep levels generated by thermal oxidation in n-type 4H-SiC[J]. Applied Physics Express, 2013, 6(5): 051301.
[4] HEMMINGSSON C, SON N T, KORDINA O, et al. Deep level defects in electron-irradiated 4H-SiC epitaxial layers[J]. Journal of Applied Physics, 1997, 81(9): 6155-6159.
[5] LUO Z Y, CHEN T B, AHYI A C, et al. Proton radiation effects in 4H-SiC diodes and MOS capacitors[J]. IEEE Transactions on Nuclear Science, 2004, 51(6): 3748-3752.
[6] LI D X, ZHANG Y M, TANG X Y, et al. Effects of 5 MeV proton irradiation on 1200 V 4H-SiC VDMOSFETs ON-state characteristics[J]. IEEE Access, 2020, 8: 104503-104510.
[7] DEÁK P, KNAUP J, THILL C, et al. The mechanism of defect creation and passivation at the SiC/SiO₂ interface[J]. Journal of Physics D: Applied Physics, 2008, 41(4): 049801.
[8] DAS M K, HANEY S K, RICHMOND J, et al. SiC MOSFET reliability update[J]. Materials Science Forum, 2012, 717/718/719/720: 1073-1076.
[9] CASTALDINI A, CAVALLINI A, RIGUTTI L, et al. Low temperature annealing of electron irradiation induced defects in 4H-SiC[J]. Applied Physics Letters, 2004, 85(17): 3780.
[10] DONG P, QIN Y Z, YU X G, et al. Electron radiation effects on the 4H-SiC PiN diodes characteristics: an insight from point defects to electrical degradation[J]. IEEE Access, 2019, 7: 170385-170391.
[11] 李东洵. 4H-SiC功率VDMOSFET器件辐照效应及加固方法研究[D]. 西安: 西安电子科技大学, 2021.
LI D X. Investigation on irradiation effects and hardening methods of 4H-SiC VDMOSFETs[D].Xi'an: Xidian University, 2021 (in Chinese).
[12] TAKAKURA K, OHYAMA H, UEMURA K, et al. Effects of radiation-induced defects on device performance in electron-irradiated SiC-MESFETs[J]. Materials Science in Semiconductor Processing, 2006, 9(1/2/3): 327-330.
[13] CHBILI Z, MATSUDA A, CHBILI J, et al. Modeling early breakdown failures of gate oxide in SiC power MOSFETs[J]. IEEE Transactions on Electron Devices, 2016, 63(9): 3605-3613.
[14] NIGAM T, KERBER A, PEUMANS P. Accurate model for time-dependent dielectric breakdown of high-k metal gate stacks[C]//2009 IEEE International Reliability Physics Symposium. Montreal, QC, Canada. IEEE, 2009: 523-530.
[15] ZHU S N, LIU T S, WHITE M H, et al. Investigation of gate leakage current behavior for commercial 1.2 kV 4H-SiC power MOSFETs[C]//2021 IEEE International Reliability Physics Symposium (IRPS). Monterey, CA, USA. IEEE, 2021: 1-7.
[16] NISKANEN K, KETTUNEN H, LAHTI M, et al. Effect of 20 MeV electron radiation on long term reliability of SiC power MOSFETs[J]. IEEE Transactions on Nuclear Science, 2023, 70(4): 456-461.
[17] POPELKA S, HAZDRA P. Effect of electron irradiation on 1700 V 4H-SiC MOSFET characteristics[J]. Materials Science Forum, 2016, 858: 856-859.
[18] COOPER J A. Advances in SiC MOS technology[J]. Physica Status Solidi Applied Research, 1997, 162(1): 305-320.
[19] AFANAS'EV V V, STESMANS A, BASSLER M, et al. Shallow electron traps at the 4H-SiC/SiO₂ interface[J]. Applied Physics Letters, 2000, 76(3): 336-338.
[20] AFANAS'EV V V, CIOBANU F, PENSL G, et al. Contributions to the density of interface states in SiC MOS structures[M]//Silicon Carbide. Berlin, Heidelberg: Springer, 2004: 343-371.
[21] BASILE A F, ROZEN J, WILLIAMS J R, et al. Capacitance-voltage and deep-level-transient spectroscopy characterization of defects near SiO₂/SiC interfaces[J]. Journal of Applied Physics, 2011, 109(6): 064514.
[22] KIMOTO T, YOSHIOKA H, NAKAMURA T. Physics of SiC MOS interface and development of trench MOSFETs[C]//The 1 st IEEE Workshop on Wide Bandgap Power Devices and Applications. Columbus, OH, USA. IEEE, 2013: 135-138.
[23] DEVYNCK F, ALKAUSKAS A, BROQVIST P, et al. Charge transition levels of carbon-, oxygen-, and hydrogen-related defects at the SiC/SiO₂ interface through hybrid functionals[J]. Physical Review B, 2011, 84(23): 235320.
[24] DEVYNCK F, ALKAUSKAS A, BROQVIST P, et al. Defect levels of carbon-related defects at the SiC/SiO₂ interface from hybrid functionals[J]. Physical Review B, 2011, 83(19): 195319.
[25] KNAUP J M, DEÁK P, FRAUENHEIM T, et al. Defects in SiO₂ as the possible origin of near interface traps in the SiCSiO₂ system: a systematic theoretical study[J]. Physical Review B, 2005, 72(11): 115323.
[26] ROZEN J, DHAR S, PANTELIDES S T, et al. Suppression of interface state generation upon electron injection in nitrided oxides grown on 4H-SiC[J]. Applied Physics Letters, 2007, 91(15): 153503.
[27] HUANG L H, LIU Y, PENG X, et al. Static performance and threshold voltage stability improvement of Al₂O₃/LaAlO₃/SiO₂ gate-stack for SiC power MOSFETs[J]. IEEE Transactions on Electron Devices, 2022, 69(2): 690-695.