[6p-A201-1~20] 15.6 Group IV Compound Semiconductors (SiC)

[6p-A201-1] Control of minority carrier lifetime of n type 4H-SiC epitaxial layer by low V doping

〇Koichi Murata¹, Takeshi Tawara^2,3, Anli Yang¹, Tetsuya Miyazawa¹, Hidekazu Tsuchida¹ (1.CRIEPI, 2.AIST, 3.Fuji Electric Co., Ltd.)

Keywords:SiC, Epitaxial growth

Controlling minority carrier lifetimes in the drift layer is crucial for 4H-SiC IGBTs and PIN diodes. To optimize the device performance, the local carrier lifetime control technique can be used to improve the trade-off relation between on-state voltage drop and switching speed. Typically the minority carrier lifetime of low doped 4H-SiC epilayer is determined by the concentration of the Z_1/2 center (C vacancy) which acts as SRH recombination center. The carbon diffusion process can improve the minority carrier lifetime over 10 μs. On the other hand, it is expected that the minority carrier lifetime can be reduced by the formation of deep levels to enhance the SRH recombination. We have demonstrated the ability to reduce carrier lifetimes down to ~20 ns by V doping in the n⁺ epilayer. In this presentation, we report the applicability of V doping to control carrier lifetimes in the 0.1 - 10 μs range.