Infrared attenuated total reflection spectroscopy of 6H–SiC(0001) and (0001) surfaces

Abstract

Fourier-transformed infrared attenuated total reflection (FTIR–ATR) spectroscopy was used to study the adsorbates on 6H–SiC(0001) and (0001̄) surfaces after chemical treatments and after heat treatments in hydrogen. We obtained clear absorption bands attributable to hydrides and oxides on the SiC surfaces. The ATR spectroscopy revealed polarity dependencies of Si–H and C–H stretch modes between the 6H–SiC(0001) and (0001̄). The surface Si–H bonds on 6H–SiC(0001) formed by the heat treatment in hydrogen were found to have a quite long life time against air exposure, and the heat treatment in hydrogen also produced a flat (0001̄) surface with ordered surface C–H bonds. The oxidation characteristics of 6H–SiC(0001) and (0001̄) surfaces were also studied, and we discussed the roles of surface treatments using H2O2 solution and H2SO4 solution at elevated temperature.