本篇論文藉由模擬來研究4H-SiC雙載子元件的導電特性，主要集中在4H-SiC PiN二極體、4H-SiC npn電晶體和4H-SiC非對稱型GTO閘流體等元件的討論。為了分析材料參數對元件的影響，分別探討直流和開關切換特性。
首先討論的是4H-SiC PiN二極體的直流特性。操作在反向偏壓時，選定飄移區的材料參數，以達到耐壓目標6.5kV；操作在順向偏壓時，一旦在飄移區發生導通率調變，會降低導通電壓降，並記錄理想因子n值。
接著討論的是4H-SiC npn電晶體的直流特性。操作在順偏主動時，從模擬結果發現表面復合速度、載子的時間常數和元件溫度都會影響共射極電流增益和特定導通電阻，然而與Si npn電晶體相比，隨著元件溫度升高，4H-SiC npn電晶體的共射極電流增益反而增加，可能是因為基極摻雜離子化增加而增加電子被復合的數量；操作在崩潰時，成功模擬BVCBO大於BVCEO的結果。
最後討論由npn和pnp電晶體耦合而成的4H-SiC非對稱型GTO閘流體的直流和開關切換特性。操作在順向導通時，從模擬結果發現一旦發生導通率調變，導通電壓降隨之減少，此特性類似4H-SiC PiN二極體；操作在崩潰時，成功模擬BVF大於BVR的結果；操作在開關切換時，隨著元件溫度越高，載子時間常數越長，導致npn和pnp電晶體的共基極注入效應的增加，進一步縮短元件被導通所需的時間，而延長元件被截止所需的時間。

In this thesis, the electrical characteristics of 4H-SiC bipolar devices are studied by simulation, and the discussion mainly focuses on PiN diode, npn transistor and asymmetrical GTO Thyrsitor. To analyze the effect of material parameters on devices, dc and switching characteristics were discussed separately.
The first part is the dc characteristics of 4H-SiC PiN diodes. During the reverse bias operation, the material parameters of the drift region are selected to achieve a target blocking voltage of 6.5 kV. However, during the forward bias operation, once conductivity modulation occurs in the drift region, the on-voltage drop will be reduced.
The second part to discuss is the dc characteristics of the 4H-SiC npn transistors. During the forward bias operation, simulation results show that recombination velocity at the surface of the emitter and the base, carrier lifetime in the base, and device temperature have significant effects both on common emitter current gain and the specific on-state resistance. However, in contrast to Si npn transistors, the common emitter current gain of 4H-SiC npn transistor increases as the temperature increases due to the increase of ionization rate of the acceptor in the base. However, during the reverse bias operation, the simulation results of open-emitter breakdown voltage BVCBO greater than open-base breakdown voltage BVCEO was successfully verified.
The last part to discuss is the dc and switching characteristics of 4H-SiC asymmetrical GTO Thyristor, with parasitic npn and pnp transistors. During the forward bias operation, the simulation results show that the effect of conductivity modulation is to reduce the on-state voltage, which is similar to PiN diodes. However, during the reverse bias operation, forward blocking voltage BVF was verified to be much larger than reverse blocking voltage BVR, owing to the asymmetric blocking structure. During the switching operation, as the temperature becomes higher, the carrier lifetime becomes longer, resulting in the increase of injection efficiency of both parasitic npn and pnp transistors, then reducing the turn-on time and extending the turn-off time.

中文摘要 ----------------------------------------------------------I
Abstract----------------------------------------------------------II
致謝--------------------------------------------------------------III
目錄--------------------------------------------------------------IV
圖目錄-------------------------------------------------------------VI
表目錄-------------------------------------------------------------X
第一章 序論--------------------------------------------------------1
1.1 碳化矽(SiC)材料簡介--------------------------------------------1
1.2 4H-SiC非對稱型可關斷閘流體 (4H-SiC Asymmetrical GTO Thyristor)--3
1.3 文獻回顧-------------------------------------------------------6
1.4研究動機與論文大綱-----------------------------------------------8
第二章 4H-SiC材料參數模型-------------------------------------------10
2.1能隙(Bandgap)模型-----------------------------------------------10
2.2遷移率(Mobility)模型--------------------------------------------12
2.3不完全游離(Incomplete ionization)模型----------------------------14
2.4載子時間常數(Carrier lifetime)模型-------------------------------15
2.5 游離化碰撞(Impact ionization)模型-------------------------------15
第三章 PiN二極體----------------------------------------------------17
3.1 PiN二極體的直流操作原理------------------------------------------17
3.2 累增崩潰機制----------------------------------------------------21
3.3模擬結果與分析---------------------------------------------------22
3.3.1 4H-SiC PiN二極體的結構模擬------------------------------------22
3.3.2 反向崩潰特性--------------------------------------------------23
3.3.3 順向導通特性--------------------------------------------------25
3.3.3.1 載子時間常數------------------------------------------------26
3.3.3.2 元件溫度(Device Temperature)--------------------------------28
第四章 BJT電晶體----------------------------------------------------32
4.1 BJT電晶體的直流操作原理------------------------------------------32
4.2 電流增益--------------------------------------------------------35
4.3 累增崩潰機制----------------------------------------------------38
4.4 模擬結果與分析--------------------------------------------------40
4.4.1 4H-SiC npn電晶體的結構模擬------------------------------------40
4.4.2 順向導通特性--------------------------------------------------41
4.4.2.1表面復合速度(Surface recombination velocity)-----------------42
4.4.2.2載子時間常數-------------------------------------------------43
4.4.2.3元件溫度----------------------------------------------------44
4.4.3 反向崩潰特性--------------------------------------------------46
第五章 GTO閘流體----------------------------------------------------48
5.1 GTO閘流體的直流操作原理------------------------------------------48
5.2 累增崩潰機制----------------------------------------------------51
5.3 GTO閘流體的交流操作原理------------------------------------------53
5.3.1 Turn-on機制--------------------------------------------------53
5.3.2 Turn-off機制-------------------------------------------------55
5.4 模擬結果與分析--------------------------------------------------57
5.4.1 4H-SiC非對稱型GTO閘流體的結構模擬------------------------------57
5.4.2 順向導通特性--------------------------------------------------58
5.4.2.1 載子時間常數------------------------------------------------59
5.4.2.2 元件溫度---------------------------------------------------60
5.4.3 崩潰特性-----------------------------------------------------61
5.4.4 Turn-on特性--------------------------------------------------63
5.4.4.1 載子時間常數------------------------------------------------65
5.4.4.2 元件溫度----------------------------------------------------66
5.4.5 Turn-off特性--------------------------------------------------67
5.4.5.1 載子時間常數-------------------------------------------------68
5.4.5.2 元件溫度-----------------------------------------------------69
5.5 4H-SiC非對稱型GTO閘流體的光罩設計----------------------------------72
第六章 結論與未來展望-------------------------------------------------74
參考文獻-------------------------------------------------------------76

[1]T. Kimoto and J. A. Cooper, Fundamentals of Silicon Carbide Technology: Growth, Characterization, Devices and Applications. Piscataway, NJ, USA: Wiley, 2014.
[2]Kwasnicki, P, “Evaluation of Doping in 4H-SiC by optical spectroscopies,” Ph.D. Thesis, Université Montpellier II-Sciences et Techniques du Languedoc, Montpellier, France, 2014
[3]A. R. Powell and L. B. Rowland, “SiC Materials-Process, Status, and Potential Roadblock,” Proceeding of the IEEE, vol. 90, no. 6, June 2002, pp.942-955.
[4]SCR(silicon controlled rectifier) -Construction and Working| Power Electronics | Electrical engineering. From https://favreadblogs.blogspot.com/2016/02/scrsilicon-controlled-rectifier.html#
[5]T. Chou, “High voltage SiC power devices,” High-Temperature Electronics in Europe, International Technology Research Institute, pp. 99-152, 2000.
[6]J. B. Casady et al., “4-H SiC power devices for use in power electronic motor control,” Solid-State Electron., vol. 42, p. 2165, 1998.
[7]A. K. Agarwal, J. B. Casady, L. B. Rowland, S. Seshadri, R. R. Siergiej, W. F. Valek, and C. D. Brandt, “700-V asymmetrical 4H-SiC gate turn-off thyristors (GTOs),” IEEE Electron Device Lett., vol. 18, p. 518, Nov. 1997.
[8]S. H. Ryu, A. K. Agarwal, R. Singh, and J. W. Palmour, “3100V asymmetrical, gate turn-off thyristors in 4H–SiC,” IEEE Electron Device Lett., vol. 22, pp. 127–129, Mar. 2001.
[9]J. W. Palmour, “SiC power devices for smart grid systems,” in Proc. IEEE Power Electron. Conf., Sapporo, Japan, Jun. 2010, pp. 1006–1013.
[10]L. Cheng et al., “Advanced silicon carbide gate turn-off thyristor for energyconversion and power grid applications,” in Proc. IEEE ECCE, 2012, pp. 2249–2252.
[11]L. Cheng, A. K. Agarwal, C. Capell, M. O'Loughlin, K. Lam, J. Richmond, Edward Van Brunt, A. Burk, J. W. Palmour, H. O'Brien, A. Ogunniyi, and C. Scozzie, “20 kV, 2 cm2, 4H-SiC gate turn-off thyristors for advanced pulsed power applications,” in 2013 19th IEEE Pulsed Power Conf. (PPC), San Francisco, CA.
[12]X. Song, A. Q. Huang, M. Lee, C. Peng, L. Cheng, H. O’Brien, A. Ogunniyi, C. Scozzie, and J. Palmour, “22 kV SiC Emitter turn-off (ETO) thyristor and its dynamic performance including SOA,” in 2015 IEEE 27th Int. Symp. Power Semiconductor Devices & IC’s (ISPSD), Hong Kong, China, pp. 277–280.
[13]X. Xu et al., "High-Voltage 4H-SiC GTO Thyristor with Multiple Floating Zone Junction Termination Extension," 2018 1st Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia), Xi'an, China, 2018, pp. 149-152.
[14]Stefanakis Dionysios. “Development of silicon carbide (SiC) micro vertical transverse field effect transistors,” Doctor Thesis, Aristotle University of Thessaloniki, 2018.
[15]Y. P. Varshni, “Temperature dependence of the energy gap in semiconductors,” Physics, vol. 34, pp. 149–154, 1967.
[16]N. Lophitis, A. Arvanitopoulos and S. Perkins, M. Antoniou, “TCAD device modelling and simulation of wide bandgap power semiconductors”, InTech – Open Access Publisher, pp. 17-44, Feb. 2018.
[17]M. Lades, “Modeling and Simulation of Wide Bandgap Semiconductor Devices: 4H/6H-SiC,” in Selected Topics of Electronics and Micromechatronics. Aachen: Shaker Verlag, 2002, vol. 3.
[18]J. S. Slotboom and H. C. de Graaf, “Measurement of bandgap and R. Rosenberg, Eds. New York: Academic, to be published. narrowing in Si bipolar transistors,” Solid-State Electron., vol. 19, no. 10, pp. 857-862, Oct. 1976.
[19]M. Nawaz, “On the assessment of few design proposals for 4H-SiC BJTs,” Microelectron. J., vol. 41, no. 12, pp. 801–808, Dec. 2010.
[20]Roschke M, Schwierz F. Electron mobility models for 4H, 6H, and 3C SiC. IEEE Transactions on Electron Devices. 2001;48(7):1442-1447.
[21]Ayalew, Tesfaye, et al. "Accurate Modeling of Lattice Site-Dependent Ionization Level of Impurities in α-SiC Devices." Simulation of Semiconductor Processes and Devices 2004. Springer, Vienna, 2004. 295-298.
[22]S. Selberherr, Analysis and simulation of Semiconductor Devices. Vienna, Austria: Springer-Verlag, 1984 and references therein.
[23]G. Donnarumma, V. Palankovski,S. Selberherr, ''Influence of Bandgap Narrowing and Carrier Lifetimes on the Forward Current-Voltage Characteristics of a 4H-SiCp-i-n Diode'', SISPA 2012, September 5-7, 2012, Denver, CO, USA.
[24]J.-Y. Jiang, H.-C. Hsu, K.-W. Chu, C.-F. Huang, and F. Zhao, “Experimental study of counter-doped junction termination extension for 4H–SiC power devices,” IEEE Electron Device Lett., vol. 36, no. 7, pp. 699–701, Jul. 2015.
[25]B. Baliga, “Fundamentals of Power Semiconductor Devices,” New York: Springer Verlag, 2008.
[26]A. Neamen, Semiconductor Physics and Devices, 3rd ed. New York: McGraw-Hill, 2003, p. 486.
[27]A. O. Konstantinov, Q. Wahab, N. Nordell, and U. Lindefelt, “Ionization rates and critical fields in 4H silicon carbide,” Appl. Phys. Lett., vol. 71, pp. 90–92, July 1997.
[28]A. Salemi, H. Elahipanah, B. Buono, A. Hallén, J. U. Hassan, P. Bergman, G. Malm, C.-M. Zetterling, and M. Östling, “Conductivity modulated on-axis 4H-SiC 10+ kV PiN diodes,” in Proc. Int. Symp. Power Semiconductor Devices IC’s, May 2015, pp. 269–272.
[29]H.-S. Lee, “Fabrication and Characterization of Silicon Carbide Power Bipolar Junction Transistors,” PhD dissertation, KTH, Stockholm, 2008.
[30]R. Sei-Hyung, A. K. Agarwal, J. W. Palmour, and M. E. Levinshtein, “1.8 kV, 3.8 A bipolar junction transistors in 4H–SiC,” in Proc. 13th Int. Symp. Power Semiconductor Devices and ICs, 2001, pp. 37–40.
[31]J. Wang and B.W. Williams, “The 4H-SiC npn power bipolar junction transistor,” Semicond. Sci. Technol., Vol. 14, pp.1088-1097, 1999.
[32]J. B. Fedison, High voltage silicon carbide junction rectifiers and GTO thyristors, Ph.D. Thesis, Rensselaer Polytechnic Institute, New York, May 2001.
[33]F. M. Bin Abdul Rahman. “6 Pulse GTO Thyristor Converter Simulation” Universiti Malaysia Pahang, May 2009.
[34]L. Lin and J. H. Zhao, "Fabrication and Characterization of 4H-SiC 6kV Gate Turn-Off Thyristor," Mater. Sci. Forum, vol. 717-720, pp. 1163-1166, 2012.
[35]J. B. Fedison, T. P. Chow, A. K. Agarwal, S. H. Ryu, R. Singh, O. Kordina, and J. W. Palmour, “Switching characteristics of 3 kV 4H–SiC GTO Thyristors,” in Proc. 58th Annu. Device Research Conf., 2000, pp. 135–136.34.