Relationship between changes in the ellipsometric parameters and the surface potential barrier of Si(III) single crystals with submonolayer coatings

Abstract

Successive removal of adsorbed gases and native oxide from surfaces of Si(III) single crystals was investigated in situ using the methods of ellipsometry and the retarding Anderson potential. It is found that changes in the ellipsometric parameters are directly proportional to changes in the height and transparency of the surface potential barrier of the single crystals studied. The observed characteristic features of the changes in the temperature dependences of the ellipsometric parameters and the retarding Anderson potential that occur with an increase in the degree of coating of single-crystal surfaces with a submonolayer adsorbate are attributed to changes in the potential barrier transparency and the work function. This approach does not require use of such parameters as thickness, refractive index, and absorption coefficient (which are used in ellipsometry) for description of submonolayer coatings.