Semiconductor device and manufacturing method thereof

Abstract

A semiconductor fabrication method includes: providing a separating wall and a plurality of liners including a first liner and a second liner between a first fin and a second fin having an epitaxial stack and a sacrificial gate stack over channel regions of the second fin; recessing a sacrificial epitaxial layer of the epitaxial stack to form a cavity; recessing the first line thereby expanding the cavity; recessing the second liner thereby expanding the cavity; forming inner spacer material in the first and second cavities; forming source/drain features; and replacing the sacrificial epitaxial layer and the sacrificial gate stack with a metal gate layer; wherein the metal gate layer has a first critical dimension (CD) measured between the inner spacer material, and wherein the first liner after recessing has a second CD measured between the inner spacer material that is approximately equal to the first CD.