Methods of forming replacement gate structures with a recessed channel

摘要

Disclosed herein are various methods of forming replacement gate structures with a recessed channel region. In one example, the method includes forming a sacrificial gate structure above a semiconducting substrate, removing the sacrificial gate structure to thereby define an initial gate opening having sidewalls and to expose a surface of the substrate and performing an etching process on the exposed surface of the substrate to define a recessed channel in the substrate. The method includes the additional steps of forming a sidewall spacer within the initial gate opening on the sidewalls of the initial gate opening to thereby define a final gate opening and forming a replacement gate structure in the final gate opening.

主权项

1. A method of forming a transistor, comprising:
forming a sacrificial gate structure above a layer of silicon; forming a first sidewall spacer adjacent said sacrificial gate structure; removing said sacrificial gate structure to thereby define an initial gate opening having sidewalls defined by said first sidewall spacer and to expose a surface of said layer of silicon; performing an etching process on said exposed surface of said layer of silicon to define a recessed channel in said layer of silicon, wherein said etching process undercuts a region beneath said first sidewall spacer; after performing said etching process, forming a second sidewall spacer within said region beneath said first sidewall spacer and within said initial gate opening on said sidewalls of said initial gate opening to thereby define a final gate opening narrower than said initial gate opening and expose said layer of silicon; and forming a replacement gate structure in said final gate opening.