This study relates generally to etching processes and in particular to method for controlling the profile of an opening etched in a SiC wafer. In the fabrication of high power device via hole is formed in an insulating layer prior to metallization to provide contacts to underlying regions. It is preferable that these openings have a low slope etch profile in order to minimize the possibility of defects in the overlying metal layer. One problem is a step-coverage defect, which sometimes occurs when a metal layer is formed over an opening having a steep profile and causes a discontinuity in the conductor formed by the metal layer. Such steep openings, that is, openings having nearly vertical sidewalls, typically occur when an SiC wafer is anisotropically etched, for example by a etch mask of high selectivity metal.

In this study, the SiC etching chatacteristics and the dry etch mechanism of SiC as function of etch mask material(metal masks) and etch mask edge shape were investigated. The etched step height was measured using step profilometer. And Scanning Electron Microscope (SEM) was used to measure the etch profile. Also, X-ray Photoelectron spectroscopy (XPS) was utilized to analyze the SiC etch mechanism.