Method of forming a low leakage dielectric layer providing an increased capacitive coupling

Abstract

A method of forming a dielectric layer that may be used as a dielectric separating a gate electrode from a channel region of a field effect transistor is provided which allows a high capacitive coupling while still maintaining a low leakage current level. This is achieved by introducing a dopant, for example nitrogen, that increases the resistance of the dielectric layer by means of low energy plasma irradiation, wherein an initial layer thickness is selected to substantially avoid penetration of the dopant into the underlying material. Subsequently, dielectric material is removed by an atomic layer etch to finally obtain the required design thickness.