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

Synchrotron x-ray photoelectron spectroscopy study of hydrogen-terminated6H−SiC{0001}surfaces

“…Figure 1 displays spectra of the Si-H and the C-H stretch modes measured on 6H-SiC(0001) and 6H-SiC(0001 ), respectively. The C-H stretch mode on SiC(0001 ) is located at (2851.5 Ϯ0.2) cm Ϫ1 , in good agreement with Tsuchida et al [38][39][40][41] On SiC͑0001͒, two Si-H stretch modes are observed at (2128.0Ϯ0.6) cm Ϫ1 and (2133.5Ϯ0.6) cm Ϫ1 , respectively. The splitting of the Si-H stretch mode, which has also been reported by Tsuchida et al, [38][39][40][41] has been a subject of a detailed study 45 and was shown to be due to a small difference in the third-neighbor interactions of the Si-H dipole with the underlying lattice, which are different for Si-H units on cubic and hexagonally terminated terraces.…”

“…The wet-chemical procedure also fails for the (0001 ) surfaces for similar reasons. 32,37 The only method to yield SiC͕0001͖ surfaces saturated with a monolayer of hydrogen was first suggested by Tsuchida et al, [38][39][40][41] who have annealed their samples in an atmosphere of ultraclean hydrogen at temperatures of 1000°C and higher. This procedure is similar to the hydrogen etching which is widely used to reduce surface roughness and polishing damage of SiC substrate surfaces prior to homoepitaxial growth by chemical vapor deposition ͑CVD͒.…”

Structural and electronic properties of epitaxial graphene on SiC(0 0 0 1): a review of growth, characterization, transfer doping and hydrogen intercalation

“…This process was carried out in a quartz-glass reactor in an atmosphere of palladium-purified ultra-pure molecular hydrogen, similar to the technique used for hydrogen etching [43,44] and hydrogen passivation [45,46,47] of SiC surfaces.…”

Hydrogen terminated4H−SiC(11¯00)andSeyller1, Graupner2, Sieber3 et al. 2005Phys. Rev. B341110View full textAdd to dashboardCite

“…This method was first suggested by Tsuchida and co-workers. [33][34][35][36] We have adopted this method and have studied the chemical, structural and electronic properties of hydrogenated 6H-SiC͕0001͖ surfaces. [37][38][39][40][41][42][43][44][45] The surfaces prepared in this way are free of unwanted contaminants, unreconstructed, chemically inert, and-within certain limits-electronically passivated.…”