Electrochemical etching modes of 4H-SiC in KOH solutions

Abstract

Electrochemical etching is a promising wet etching technology for preparing porous structures and the flat surface etching of 4H-SiC. In this study, the effects of current density and KOH concentration on the etching of 4H-SiC were investigated. We found that the respective mechanisms for preparing porous structures and flat surface etching differed. The porous and flat etching modes were proposed to clarify the mechanistic differences. In addition, we achieved an etch rate of 1 μm h−1 in flat etching mode, and the sample surface was improved for 4H-SiC applications in the field of optoelectronics and microelectronics through the thermal oxidation of SiC.