Rough silicon surfaces studied by optical methods

Abstract

In this paper a detailed analysis of influence of random surface roughness on values of ellipsometric parameters and reflectance of a simple rough boundary of silicon and of a system silicon substrate-nonabsorbing thin film with rough boundaries is presented. The analysis is carried out mainly from the practical viewpoint, i.e. the changes in ellipsometric parameters and reflectance which are obtained in consequence of the influence of surface roughness are discussed. Here also attention has especially been paid to the complications in interpretation of ellipsometric parameters arising due to the above mentioned changes. It is shown that using both the dependence of ellipsometric parameters on the angle of incidence and the spectral dependence of the relative reflectance at normal incidence the fundamental parameters characterizing the randomly rough surface may be determined.