Hydrogen etching of 4H–SiC(0001) facet and step formation

Abstract

SiC has attracted much interest due to its vast applications in high power, high frequency and radiation-hardened electronics at high temperatures. Although the growth and processing technology for SiC wafers has matured, scratches created during surface preparation will unavoidably deteriorate both device performances and the quality of materials which are fabricated on it. Hydrogen etching has been proposed as an effective approach to obtain ideal SiC surfaces with large atomically flat steps. Here, we reported a systematical investigation on the effects of processing parameters to the hydrogen etching of 4H–SiC (0001). Accordingly, a new two-step etching method was developed with a specifically designed crucible to take advantage of the found correlation between those parameters and the terrace features. The method demonstrates high efficiency to realize atomically uniform SiC surface morphology with more than 70% coverage of the sample surface. It offers a possible route for large scale industrial SiC wafer planarization.