Method of manufacturing a semiconductor device and a semiconductor device

Abstract

In a method of manufacturing a semiconductor device, a fin structure in which first semiconductor layers and second semiconductor layers are alternately stacked over a bottom fin structure protruding from a substrate, is formed. A sacrificial gate structure is formed over the fin structure. A source/drain region of the fin structure is etched, thereby forming a source/drain space. The first semiconductor layers are laterally etched through the source/drain space. An inner spacer is formed on an end of each of the etched first semiconductor layers. One or more epitaxial layers are formed in the source/drain space, and the sacrificial gate structure is replaced with a metal gate structure. A width of the source/drain space at a bottommost one of the first semiconductor layers is greater than a width of the source/drain space at one of the first semiconductor layers above the bottommost one of the first semiconductor layers.