Scanned light pulse technique for the investigation of insulator–semiconductor interfaces

Abstract

A new measurement method, scanned light pulse technique, for the investigation of the interface properties of metal–insulator–semiconductor (MIS) structures is introduced. The measured signal is the charge contents of current transients induced by light pulses applied to the investigated sample. This signal depends on surface potential, interface state density and voltage applied to the MIS structure. By analyzing the results of such measurements it is quantitatively demonstrated how insulator charge and interface state distribution influence the voltage dependence. By scanning a light spot across the surface of an MIS structure with transparent metal electrode it is further shown that pictures of the spatial variation of the surface potential and the interface state density can be obtained.