Comments on ``Dependence of barrier height of metalhyphen;semiconductor contact (Ausngbnd;GaAs) on thickness of semiconductor surface layer''

摘要

Experimental results on the dependence of the Ausngbnd;GaAs barrier height on the thicknessdof the oxide film reported by Pruniaux and Adams indicate that PHgr;Bequals;PHgr;iplus;Ad. This communication shows that neglecting the effect of surface states in the Cowleyhyphen;Sze model predicts a linear decrease of barrier height with increasing oxide thickness. The observed increase of barrier height with increasing oxide thickness may be partly due to surface states at the oxidehyphen;semiconductor interface. A model that includes the effects of surface states and of screening on the metal side is proposed to explain the various values for PHgr;i.