Multiple-thickness gate oxide formed by oxygen implantation

Abstract

A semiconductor device including a gate oxide of multiple thicknesses for multiple transistors where the gate oxide thicknesses are altered through the growth process of implanted oxygen ions into selected regions of a substrate. The implanted oxygen ions accelerate the growth of the oxide which also allow superior quality and reliability of the oxide layer, where the quality is especially important, compared to inter-metal dielectric layers. A technique has been used to vary the thickness of an oxide layer grown on a silicon wafer during oxidation growth process by implanting nitrogen into selected regions of the substrate, which the nitrogen ions retard the growth of the silicon oxide resulting in a diminished oxide quality. Therefore it is desirable to fabricate a semiconductor device with multiple thicknesses of gate oxide by the implanted oxygen ion technique.

Dependencies are inferred from the claim text.