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

△ [6p-A201-6] Relationship between Current Density and Stacking Fault Expansion Origin in Forward Degradation of 4H-SiC PiN Diode (II)

〇SHOHEI HAYASHI^1,2, TAMOTSU YAMASHITA^1,3, JUNJI SENZAKI¹, MASAKI MIYAZATO^1,4, MINA RYO^1,4, MASAAKI MIYAJIMA^1,4, TOMOHISA KATO¹, YOSHIYUKI YONEZAWA¹, KAZUTOSHI KOJIMA¹, HAJIME OKUMURA¹ (1.AIST, 2.Toray Research Center, 3.SHOWA DENKO, 4.Fuji Electric)

Keywords:silicon carbide, forward current degradation, basal plane dislocation

In 4H-SiC bipolar devices, forward current degradation is crucial issue. Single Shockley-type stacking fault (SF) constituting a basal plane dislocation (BPD) expands along the basal-plane due to the electron-hole recombination. The SF expansion causes the forward-current degradation of bipolar devices. In our previous works, a relationship between current density and stacking fault expansion origin in forward degradation of 4H-SiC PiN diodes was investigated. BPDs in epitaxial layer formed SFs in the condition of lower current density. In contrast, SFs were formed from BPDs in substrate converted into threading edge dislocations (TED) at the interface between epitaxial layer and substrate in the condition of higher current density. These results indicate that the position with basal-plane dislocation strongly affects the threshold current of the stacking fault expansion. Also, the SF expansion originating from BPD converted into TED widely distributed from 350 to 600 Acm^-2. In this study, we investigated the BPD-TED conversion point in detail for clarifying the current density variation of SF expansion originated from BPD converted into TED.