Nanosheet transistor with asymmetric junction and robust structure stability

Abstract

A semiconductor structure includes a substrate; bottom dielectric isolation (BDI) on the substrate; a first source/drain region on the BDI; and a nanosheet stack on the BDI. The nanosheet stack includes gate stack layers; semiconductor nanosheets interleaved with the gate stack layers and contacting the first source/drain region; and first inner spacers adjacent to the first source/drain region and separating the first source/drain region from the gate stack layers. The structure also includes a second source/drain region contacting the semiconductor nanosheet and extending from the top of the nanosheet stack down through the BDI to the substrate. Accordingly, the nanosheet stack also includes second inner spacers in the nanosheet stack adjacent to the second source/drain region and separating the second source/drain region from the gate stack layers.