Nanostructure field-effect transistor device and methods of forming

Abstract

A method of forming a nanostructure field-effect transistor (nano-FET) device includes: forming a fin structure that includes a fin and alternating layers of a first semiconductor material and a second semiconductor material overlying the fin; forming a dummy gate structure over the fin structure; forming source/drain regions over the fin structure on opposing sides of the dummy gate structure; removing the dummy gate structure to expose the first and second semiconductor materials under the dummy gate structure; selectively removing the exposed first semiconductor material, where after the selectively removing, the exposed second semiconductor material remains to form nanostructures, where different surfaces of the nanostructures have different atomic densities of the second semiconductor material; forming a gate dielectric layer around the nanostructures, thicknesses of the gate dielectric layer on the different surfaces of the nanostructures being formed substantially the same; and forming a gate electrode around the gate dielectric layer.