The Effects of H2 and HF Treatments on SiC Surfaces.

Abstract

The effects of H2-and HF-on SiC{0001} surfaces interms of morphology and adsorbates have been investigated. High temperature annealing in a H2 ambient produces a flat surface without macro-step bunching for on-axis 6H-SiC (0001) and 8 off 4H-SiC(0001). Fourier-transformed infrared attenuated total reflection (FTIR-ATR) spectra show that surface Si-H bonds are formed on 6H-SiC(0001) and surface C-H bonds are formed on SiC(0001) by H2 treatments. The sequence of thermal oxidation and HF etching also produces on-axis 6H-SiC(0001) with a stepped morphology; however, the density of surface Si-H bonds on the SiC(0001) surface after this treatment is lower than our detection limit. The chemical characteristics of surface Si-H bonds on SiC(0001) formed by H2 treatment has also been discussed.