Study of SiC Trench Etching Characteristics for Different Crystal Planes

We have successfully demonstrated comprehensive trench etching of 4H-SiC across various crystal orientations. The results show that both the trench profile and etching depth are unaffected by changes in crystal plane orientation. We achieved our target trench etching depth of 1.9 µm, with vertical sidewall profile angles ranging from 87º to 90º for different crystal planes. Additionally, we performed a qualitative analysis of sidewall roughness for various crystal planes using a 3DAFM scan. It was observed that crystal angles from-60º to-90º exhibited lower surface roughness. We have also explained the mechanisms associated with these surface roughness characteristics.