Low undercut n-p work function metal patterning in nanosheet replacement metal gate process

Abstract

A method of forming a semiconductor structure includes forming first and second stacked nanosheet channel structures on a semiconductor substrate, with each nanosheet channel structure including a plurality of stacked channel regions interspersed with sacrificial regions. In a resulting semiconductor structure, an N-type stacked nanosheet channel structure is formed on the semiconductor substrate, and a P-type stacked nanosheet channel structure is formed adjacent to the N-type stacked nanosheet channel structure on the semiconductor substrate. Each of the adjacent N-type and P-type stacked nanosheet channel structures includes a plurality of stacked channel regions with each such channel region being substantially surrounded by a gate dielectric layer and a gate work function metal layer. The gate dielectric and gate work function metal layers of the adjacent N-type and P-type stacked nanosheet channel structures are substantially eliminated from a shared gate region between the adjacent N-type and P-type stacked nanosheet channel structures.