Nature of band bending at semiconductor surfaces by contactless electroreflectance

The nature of the band bending at semiconductor surfaces (and related carrier type) is an important materials parameter. We demonstrate that an electroreflectance mode which employs a capacitorlike configuration can conveniently be used for this evaluation in a contactless manner. Results will be presented on n- and p-type bulk GaAs, semi-insulating GaAs, nominally undoped In0.15Ga0.85As and n- and p-type GaAs and InP structures with large, almost uniform electric fields.