[21a-M206-1~13] 13.7 Compound and power devices, process technology and characterization

△ [21a-M206-6] Evaluation of threshold voltage shift in SiC MOSFETs by AC gate stress

〇(M1)Yuya Enjoji¹, Noriyuki Iwamuro¹, Hiroshi Yano¹ (1.Univ. of Tsukuba)

Keywords:SiC, threshold voltage shift, AC stress

SiC-MOSFETs have problems of threshold voltage shift (ΔV_th) caused by carrier trapping at a large amount of interface states and oxide traps located at the SiO₂/SiC interface. However, the detailed mechanism of the permanent shift driven by AC gate stress have not been revealed yet. AC stress tests were conducted under various conditions to reveal the mechanism of ΔV_th. It was shown that a large positive ΔV_th by bipolar AC stress which repeat inversion and accumulation, and that the amount of recombination and the number of recombination had a great impact on ΔV_th.