Patent ID: 6406998
Filing Date: 2002-06-18
Classification: H01L

Abstract:
A method of forming an electrical contact on a silicon substrate the method comprising the steps of:providing a silicon substrate; forming a dual gate structure on the silicon substrate with an aperture in the dual gate structure; forming a layer of silicon nitride over the dual gate structure, the silicon nitride layer entering into the aperture and substantially insulating the dual gate structure from the aperture; forming an insulating layer over the silicon nitride layer and the aperture; planarizing the insulating layer; forming a contact opening through the insulating layer to the silicon substrate, the contact opening including at least a portion of the aperture, the contact opening having a bottom and an aspect ratio greater than about 4 to 1; implanting metal ions into the contact opening; and annealing the silicon substrate at a temperature and for a time sufficient to result in the formation of a metal silicide layer of substantially uniform thickness in the bottom of the contact opening, the metal silicide layer including the implanted metal ions wherein the step of forming the contact opening comprises patterning the insulating layer, the patterned insulating having a surface around the contact opening, and after the step of implanting metal ions, removing a surface layer of the patterned insulating layer where the metal ions are present to remove the metal ions that are implanted into the surface of the patterned insulating layer around the contact opening during the step of implanting metal ions into the contact opening.