US Patent 10032867 Forming bottom isolation layer for nanosheet technology

A method of forming a semiconductor structure includes forming a multi-layer structure. The multi-layer structure has a substrate and two or more nanosheet layers formed above the substrate. The method also includes forming a bottom isolation layer between the substrate and the two or more nanosheet layers. The method further includes performing a fin reveal in the multi-layer structure after formation of the bottom isolation layer to form a fin. The two or more nanosheet layers provide a channel stack for a nanosheet field-effect transistor.