Comprehensive Study of Impact Ionization Coefficients of 4H-SiC

作     者：T. Hatakeyama T. Watanabe K. Kojima N. Sano T. Shinohe K. Arai 

作者机构：Corporate Research & Development Center Toshiba Corporation 1 Komukai Toshiba-cho Saiwai-ku Kawasaki 212-8582 Japan National Institute of Advanced Industrial Science and Technology Power Electronics Research Center Tsukuba Center 2 1-1-1 Umezono Tsukuba Ibaraki 305-8568 Japan Institute of Applied Physics University of Tsukuba 1-1-1 Tennodai Tsukuba Ibaraki 305-8577 Japan 

出 版 物：《MRS Online Proceedings Library (OPL)》 

年 卷 期：2011年第815卷第1期

页      面：J9.3-J9.3页

摘      要：The electric field dependence and anisotropy of the impact ionization coefficients of 4H-SiC are investigated by means of the avalanche breakdown behavior of p+n diodes. The breakdown voltages as a function of doping density and the multiplication factors of a leakage current are obtained using p+n diode fabricated on (0001) and (1120) 4H-SiC epitaxial wafers. The obtained impact ionization coefficients show large anisotropy; the breakdown voltage of a p+n diode on (1120) wafer is 60% of that on (0001) wafer. We have shown that anisotropy of the impact ionization coefficients is attributable to the anisotropy of saturation velocity originated from the electronic structure of 4H-SiC.