As one of the third generationsemiconductor materials

Si C has outstanding properties such as wide bandgap

high critical breakdown electric field

high electron drift velocity and high thermal conductivity

therefore it is currently attracted lots of attention and has been widely studied as a promising materials candidate for the application of power electric devices. Inductively coupled plasma（ ICP） equipment is adopted to etch 4 H-SiC for etching process research. This etching experiment uses Si O2 as the mask and SFx/O2 as the process gas

through a series of process parameters adjustment and corresponding etching results analysis

the effects of ICP source power

RF bias power

O2 flow and pressure on the Si C etching rate

etching selectivity ratio and profile are investigated and the optimized conditions are achieved. Finally high quality trench structure with round-shape trench bottom and vertical sidewall has been obtained after the post-process. The trench structure plays a key role in optimizing the performance of 4 H-SiC power UMOSFET.