Spatial distribution of trapped holes in SiO2

Abstract

Spatial distribution of trapped holes and the position of charge centroid in the insulating layer of a metal-oxide-semiconductor (MOS) structure are determined after substrate hot-hole injection experiments using MOS transistors with very thin oxides. Considerable hole trapping is observed even in samples with extremely thin (∼4.6 nm) oxide film. Most of the trapped holes exist between 2-6 nm from the Si/SiO2 interface. Trapped holes are found to be distributed in the form of an exponentially decaying function of distance from the same interface. Charge centroid is determined to be located at 3.2 nm from the Si/SiO2 interface for the oxide thickness range used in this study.