Non-volatile memory having individually optimized silicide contacts and process therefor

Abstract

In an integrated-circuit memory, performance is increased by reducing an electrical contact resistance between a metal layer and an upper poly layer (a control gate poly). The electrical contact resistance is reduced by increasing the thickness of a silicide layer between the metal layer and the upper poly layer. The memory has a memory cell region and a non-memory cell region. The thickness of the silicide layer is typically restricted by consideration of integrated-circuit fabrication geometry for each memory cell not to exceed a predetermined aspect ratio. The present implementation allows independent optimization of the thickness of silicide layer in the memory cells region and the non-memory cell region. In particular, in the non-memory cell region, a thicker silicide layer significantly improves the contact resistance of a slit contact for components having the upper poly layer in contact with a lower poly layer (a floating gate poly).