Process for forming a metal-silicide gate for dynamic random access memory

摘要

A process for forming a titanium disilicide conductive layer on the upper surface of a poly gate is implemented within a self-aligned contact process. In this process, the poly layer is first formed followed by sputtering thereon of a refractory metal layer such as titanium. This is then covered by a nitride or oxide capping layer (18). A gate electrode mesa is then formed which will then have a layer of oxide (26) deposited thereon by an LPCVD technique. The temperature of this oxide deposition is such that the refractory metal layer (16) will react with the underlying poly layer (14) to form a titanium disilicide layer (28). This requires the temperature to be in excess of 600 DEG C. for this step. Thereafter, the layer (26) will be utilized to form a sidewall spacer region.