Correlation of electronic surface properties and surface structure on cleaved silicon surfaces

Abstract

The clean, cleaved Si (111) surface exhibits a 2×1 LEED structure which converts to the Si (111)-7 structure upon anneal at elevated temperatures. The conversion temperature was determined to be 370°C. Measurements taken at room temperature indicate that, after passing through a maximum, the surface conductivity decreases with increasing annealing temperature up to the conversion temperature. For higher annealing temperatures the surface conductivity increases again as the Si (111)-7 structure develops. The correlation of LEED pattern with the change of surface conductivity demonstrates that the surface states at the clean Si (111) surface are strongly dependent on surface atomic arrangement with respect to superstructure and domain boundaries.