SiC Etch with Inductively Coupled Plasma for Power Device Applications

In the next-generation power device applications, SiC materials with high thermal stability and wide bandgap exhibit outstanding performance, leading to a growing market share. Inductively coupled plasma (ICP) etch is one of the key processes in SiC device fabrication, directly impacting the electrical performance and yield of power devices. In this study, the latest 8-inch ICP etching machine developed by AMEC was utilized on SiC etching, achieving high etch rate, high selectivity, and excellent profiles. By optimizing the ratios of SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf>, O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, and Ar gases, SiC etch rate exceeding 7500 Å/min were achieved, with a SiC/SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> selectivity approaching 6. Furthermore, it was observed that the top critical dimension (TCD) size is closely correlated with the chemical etching process. Using enthetic passivation gas such as SiF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> can effectively protect the sidewall from the chemical etching during SiC etch. During the pattern transfer etch process, vertical sidewall profiles and smooth bottom rounded corners were achieved by adjusting ICP parameters. These innovations provide important insights for further optimization of SiC etch processes and enhancement of power device performance.