Electroreflectance spectra of thin silicon films

Electroreflectance spectra for thin silicon films have been investigated in the photon energy region 2.8–5.0 eV. The critical point energy E 1 ( E′' 0 ) and the broadening parameter Γ were determined for unexposed and ion-bombarded surfaces. Definite correlation between Γ -1 and the Hall mobility was found. It is concluded that the variations in E 1 ( E '0 ) for the films are caused by the emergence of density “tails” and the existence of inward mechanical microtensions.