Quantitative investigation of hydrogen bonds on Si(100) surfaces prepared by vapor phase epitaxy

Abstract

The authors investigated Si(100) surfaces prepared by vapor phase epitaxy (VPE) using Fourier transform infrared spectroscopy (FTIR) in an attenuated total reflection configuration and low energy electron diffraction (LEED). They detected the symmetric and antisymmetric stretch modes of the H–Si–Si–H monohydrides using FTIR in agreement with the associated (2×1)/(1×2) LEED patterns. Polarized FTIR measurements verified the surface character of the observed hydrogen bonds. Exchanging the process gas in our VPE reactor to argon at an intermediate temperature of around 700 °C showed the impact of the hydrogen ambient during the cooling phase at the end of the process. The authors were able to obtain a strong preference of one of the two possible surface domains by variation of the cooling procedure and quantified the domain ratio by comparison of the absorption due to the antisymmetric modes in polarized spectra parallel and perpendicular to the plane of incidence.