Fabrication of integrated devices using nitrogen implantation

Abstract

A process is provided for forming an isolating nitride film to isolate gate polysilicon of a gate structure. Specifically, the process comprises providing a channel region defined by a source and drain region of a semiconductor substrate having a gate structure comprising an isolating oxide layer positioned on the channel region and the polysilicon layer positioned on the oxide layer. More specifically, the process comprises the steps of forming the nitrogen implanted regions over the semiconductor substrate by implanting nitrogen atoms into those regions and growing spacers from exposed portions of the polysilicon layer. During the spacer growth, the spacer grows vertically as well as laterally extending under the polysilicon edges. Diffusion of nitrogen atoms to the substrate surface forms silicon nitride under the gate edges, which minimizes current leakages into gate polysilicon.