Ultrasonic-assisted anodic oxidation of 4H-SiC (0001) surface

Abstract

An ultrasonic-assisted electrochemical mechanical polishing (UAECMP) technique that combines ultrasonic vibration and electrochemical mechanical polishing (ECMP) is proposed. The effect of ultrasonic vibration on the anodic oxidation rate of a 4H-SiC (0001) surface was studied, and it was confirmed that ultrasonic vibration significantly enhanced the anodic oxidation of SiC. Compared with conventional anodic oxidation, the oxidation rate increased by about 34% with ultrasonic assistance (UA) in the initial oxidation stage, and by about 11% during subsequent anodic oxidation. In addition, the oxidation can be promoted continuously with increasing oxidation time owing to the porous structure of the oxide layer. UAECMP is very promising as an efficient finishing technique for SiC surfaces. Keywords: Silicon carbide, Ultrasonic-assisted electrochemical mechanical polishing, Ultrasonic-assisted anodic oxidation, Ultrasonic vibration