本論文探討輻射對於4H碳化矽金氧半場效電晶體的影響，主要討論的機制為伽瑪射線產生的總游離劑量和高能質子射束產生的單次事件效應，總游離劑量分為兩部分，第一部分為市售1.2kV級金氧半場效電晶體封裝元件受到不同方向照射的影響，元件受到55kGy的伽瑪射線水平方向照射，其閾值電壓降低較垂直方向照射顯著，閾值電壓降低使得在VD為10V、VG為20V時，ID-VD電流分別增加了38.05%以及35.19%，第二部份針對3.3kV級金氧半場效電晶體不同通道長度、接面場效電晶體寬度、JTE摻雜劑量與反向摻雜接面終端延伸結構的元件結構變化，分析元件在多次累積輻射劑量的失效機制，照射劑量達到400kGy時，鈍化層的累積正電荷使崩潰電壓降低少於390V，此外，矽材料的IGBT元件在伽馬射線累積10kGy照射劑量後元件失效。在單次事件效應的實驗中，採用市售650V 接面位障蕭基二極體，施加逆偏壓500V以高能質子射束進行照射，並討論照射前後接面位障蕭基二極體的電性及材料變化。

This thesis discusses the radiation effects on 4H-SiC devices. The main mechanisms are total ionizing dose (TID) effect and single event effect (SEE). Total ionizing dose (TID) effect is divided into two parts. The first part is about 1.2kV commercial 4H-SiC power MOSFETs irradiated by gamma ray in different directions. The threshold voltage (Vth) shifts negatively in all cases and devices irradiated in the horizontal direction shifts more than those irradiated in the vertical direction. Measurement of ID-VD shows an increase in the drain current by 38.05% in the horizontal direction and 35.19% in the vertical direction at VD=10V, VG=20V after 55kGy gamma radiation dose. The second part is for 3.3kV 4H-SiC power MOSFETs with different channel length, JFET width, dose of JTE and CD-JTE. The failure mechanism of 4H-SiC MOSFETs is examined after different accumulated gamma radiation dose. When the gamma radiation dose reaches 400kGy, the breakdown voltages of the 4H-SiC MOSFETs are decreased due to the positive charge accumulated in passivation layer, but only by less than 390V. In contrast, Si IGBTs irradiated in parallel failed at a gamma radiation dose of 10kGy. In the experiment of Single Event Effect, the 650V commercial 4H-SiC Junction Barrier Schottky diodes (JBS) are applied with a 500V reverse bias during the high energy proton irradiation. The electrical characteristic and material properties of JBS is examined after irradiation.

參考文獻
[1] T. Kimoto and J. A. Cooper, “Fundamentals of Silicon Carbide Technology: Growth, Characterization, Devices, and Applications,” John Wiley & Sons Singapore Pte. Ltd. 2014.

[2] B. J. Baliga, “Silicon Carbide Power Devices,” World Scientific Publishing Co. Pte. Ltd. 2005.

[3] J. A. Cooper, M. R. Melloch, R. Singh, A. Agarwal and J. W. Palmour, “Status and prospects for SiC power MOSFETs,” IEEE Transactions on Electron Devices, vol. 49, no. 4, pp. 658–664, 2002.

[4] A. A. Lebedev , V. V. Kozlovski, N. B. Strokan, D. V. Davydov, A. M. Ivanov, A. M. Strel'chuk and R. Yakimova, “Radiation hardness of the Silicon Carbide,” Materials Science Forum, vol. 433, pp. 957-960, 2003.

[5] J. Lefevre, J. M. Costantini, S. Esnouf and G. Petite, “Silicon threshold displacement energy determined by photoluminescence in electron-irradiated cubic silicon carbide,” Journal of Applied Physics, vol. 105, 023520, 2009.

[6] D. Braunig, D. Fritsch, B. Lehmann and A.L. Barry, “Radiation-induced displacement damage in silicon carbide blue light-emitting diodes,” IEEE Transactions on Nuclear Science, vol.39, pp. 428-430, 1922.

[7] C. F. Huang, H. C. Hsu, K. W. Chu, L. H. Lee, M. J. Tsai, K. Y. Lee and F. Zhao, “Counter-Doped JTE, an Edge Termination for HV SiC Devices With Increased Tolerance to the Surface Charge,” IEEE Transaction on Electron Devices, vol. 62, no. 2, 2015.

[8] B. G. Streetman, S. K. Banerjee, “Soild State Electronic Devices, seventh edition,” Pearson, 2015.

[9] W. J. Broad, “Nuclear Pulse (I): Awakening to the Chaos Factor,” Science, vol. 212, pp. 1009-1012, 1981.

[10] W. J. Broad, “Nuclear Pulse (II): Ensuring Delivery of the Doomsday Signal,” Science, vol. 212, pp. 1116-1120, 1981.

[11] W. J. Broad, “Nuclear Pulse (III): Playing a Wild Card,” Science, vol. 212, pp. 1248-1251, 1981.

[12] G. B. Roper and R. Lowis, “Development of a Radiation Hard N-Channel Power MOSFET,” IEEE Transactions on Nuclear Science, Vol. NS-30, No. 6, 1983.

[13] P. J. McWhorter and P. S. Winokur, “Simple technique for separating the effects of interface traps and trapped-oxide charge in metal-oxide-semiconductor transistors,” Applied Physics Letters, vol.48, pp. 133, 1986.

[14] D. M. Fleetwood, S. S. Tsao, and P. S. Winokur, “Total-Dose Hardness Assurance Issue for SOI MOSFETS,” IEEE Transactions on Nuclear Science, vol. 35, no. 6, 1988.

[15] T. Sakai and T. Yachi, “Effects of Gamma-Ray Irradiation on Thin-Gate-Oxide VDMOSFET Characteristics,” IEEE Transcation on Electron Devices, vol. 38, no. 6, 1991.

[16] M. Yoshikawa, H. Itoh, and Y. Morita, “Effects of gamma-ray irradiation on cubic silicon carbide metal-oxide-semiconductor structure,” Journal of Applied Physics, vol. 70, pp. 1309, 1991.

[17] A. Akturk, J. M. McGarrity, S. Potbhare and N. Goldsman, “Radiation Effects in Commercial 1200 V 24 A Silicon Carbide Power MOSFETs,” IEEE Transaction on Nuclear Science, vol. 59, no. 6, 2012.

[18] T. Matsuda, T. Yokoseki, S. Mitomo, K. Murata, T. Makino, H. Abe, A. Takeyama, S.Onoda, Y. Tanaka, M. Kandori, T. Yoshie, Y. Hijikata and T. Ohshima, “Change in Characteristics of SiC MOSFETs by Gamma-ray Irradiation at High Temperature,” Materials Science Forum, vol.858, pp. 860-863, 2016.

[19] A. Takeyama1, T. Matsuda, T. Yokoseki, S. Mitomo, K. Murata, T. Makino1, S. Onoda1, S. Okubo, Y. Tanaka, M. Kandori, T. Yoshie, Y. Hijikata and T. Ohshima1, “Improvement of radiation response of SiC MOSFETs under high temperature and humidity conditions,” Japanese Journal of Applied Physics, vol. 55, 104101, 2016.

[20] A. E. Waskiewicz, J. W. Groninger, V. H. Strahan and D. M. Long, “Burnout of Power MOS Transistors with Heavy Ions of Californium-252,” IEEE Transactions on Nuclear Science, vol. NS-33, no. 6, 1986.

[21] S. Liu, M. Boden, D. A. Girdhar and J. L. Titus, “Single-Event Burnout and Avalanche Characteristics of Power DMOSFETs,” IEEE Transactions on Nuclear Science, vol. 53, no. 6, 2006.

[22] G. Busatto, V. D. Luca, F. Iannuzzo, A. Sanseverino, and F. Velardi, “Single-Event Effects in Power MOSFETs During Heavy Ion Irradiations Performed After Gamma-Ray Degradation,” IEEE Transaction on Nuclear Science, vol. 60, no. 5, 2013.

[23] H. Asai, I. Nashiyama, K. Sugimoto, K. Shiba, Y. Sakaide, Y. Ishimaru, Y. Okazaki, K. Noguchi, and T. Morimura, “Tolerance Against Terrestrial Neutron-Induced Single-Event Burnout in SiC MOSFETs,” IEEE Transaction on Nuclear Science, vol. 61, no. 6, 2014.

[24] A. Akturk, R. Wilkins, J. McGarrity and B. Gersey, “Single Event Effects in Si and SiC Power MOSFETs Due to Terrestrial Neutrons,” IEEE Transaction on Nuclear Science, vol. 64, no. 1, 2017.

[25] A. F. Witulski, D. R. Ball, K. F. Galloway, A. Javanainen, J. M. Lauenstein, A. L. Sternberg and R. D. Schrimpf, “Single-Event Burnout Mechanisms in SiC Power MOSFETs,” IEEE Transaction on Nuclear Science, vol. 65, no. 8, 2018.

[26] C. M. Dozier, D. B. Brown, J. L. Throckmorton and D. I. Ma, “Defect Production in SiO2 by X-Ray and Co-60 Radiations,” IEEE Transaction on Nuclear Science, vol. 32, issue 6, 1985.

[27] X. liu, Y. Lei, and Y. Cheng, “Total-Dose Radiation Response and Post-Irradiation Annealing Response of Hafnium Capacitors,” IEEE International Symposium on the Applications of Ferroelectrics, 2016.

[28] T. Funaki, T. Kimoto and T. Hikihara, “Evaluation of Capacitance-Voltage Characteristics for High Voltage SiC-JFET,” IEICE Electronics Express, vol. 4, no. 16, 2007.