Planarization of a polysilicon layer surface by chemical mechanical polish to improve lithography and silicide formation

摘要

A new device and technique to realize an improved integrated circuit device incorporates an improved polysilicon upper surface. This improvement is achieved by approximately planarizing an upper surface of the polysilicon layer. First, the polysilicon layer is preferably formed as a relatively thicker layer as compared to the layer thickness in a conventional device. Then a portion of the polysilicon layer is removed, preferably utilizing a chemical mechanical polish technique. Thus, this embodiment achieves a relatively planarized upper surface of the polysilicon layer. Then, for example, a conventional metal or silicide layer may be formed upon the relatively planarized polysilicon layer. This approximately planarized upper surface of the polysilicon layer allows for a silicide layer to be formed with a relative reduction in the amount and/or severity of the conventional word line voids and seams.