Effect of Preparation-Induced Surface Morphology on the Stability of H-Terminated Si(111) and Si(100) Surfaces

摘要

The non-destructive and surface-sensitive method surface photovoltage (SPV) technique as well as ultraviolet-visible (UV-VIS) and Fourier-transform infrared (FTIR) spectroscopic ellipsometry (SE) were employed to investigate the influence of the preparation-induced surface morphology of wet-chemically treated silicon wafers on the stability of the surface passivation against native oxidation in clean room air. It was shown that the progression of the initial oxidation phase on wet-chemically prepared H-terminated surfaces strongly depends on the remaining surface microroughness and interface state density. Best results were obtained on atomically flat NH_4F-treated Si(111) surfaces prepared in N_2 atmosphere without rinsing, characterised by a very low initial interface state density D_(it,min) < 2 * 10~(10) cm~(-2)eV~(-1) and very long initial phases of oxidation up to 48 h.