关键词: RC-IGBT, 积累层沟道, 4H-SiC/Si/4H-SiC异质结集电区, 电压折回现象

Abstract: A kind of silicon carbide based enhanced-mode reverse-conducting insulated gate transistor integrated with accumulation layer channel and 4H-SiC/Si/4H-SiC heterojunction collector (HJC) is devised, which is abbreviated as HJC-RC-ACCUIGBT. The accumulation-layer channel rather than inversion-layer one is adopted to raise the channel mobility, while reduce the threshold voltage V_th, specific on-resistance R_on,sp, adverse effect from interfacial states within the gate-oxide/semiconductor-channel. A 4H-SiC/Si/4H-SiC HJC instead of n⁺ 4H-SiC homogeneous one is employed to block the outflow of electrons under low-voltage condition, while enhance the conductance modulation and decrease the forward voltage-drop V_on, and further eliminate the snapback phenomenon without weakening the other electrical performance. The structure, static and dynamic characteristics of the proposed IGBT are simulated and optimized by using the technology computer aided design‌ (TCAD) software. The results show that, compared to the counterpart with the inversion-layer channel, the V_th of the proposed IGBT is reduced by 15%, the saturation current density of the collector J_CE is increased by 32%, the influence from the interfacial states is considered. The Snapback phenomenon in this IGBT is eliminated, and the V_on and reverse conduction voltage-drop V_ron are respectively reduced by 72% and 12% comparing to the counterpart with the HJC. There exists no significant influence from the interface states within the HJC on electrical properties of the device. This paper provides a new solution for devising the high-performance RC-IGBTs.

Key words: RC-IGBT, accumulation layer channel, 4H-SiC/Si/4H-SiC heterojunction collector, snapback phenomenon