Trench Etch for SiC Power Devices

Nowadays, SiC MOSFET is widely believed to compete with Si-IGBT for its low energy loss during fast switching, in which a trench structure could play an important role to reduce the channel resistance. In this paper, we focus on ICP etch of SiC trench. Gas ratio, radio power and substrate temperature were found to have influence on SiC etch rate, selectivity to SiO2 mask and sidewall profile. Through delicate optimizing, top corner rounding and bottom corner rounding can be achieved in ICP process.