A semiconductor device includes a plurality of nano sheet stacks disposed above a substrate. Each nanosheet stack has a first nanosheet and a first sacrificial layer, the first nanosheet and the first sacrificial layer each include a first end and a second end. The first end and the second end of the first sacrificial layer are recessed from the first and second ends of the first nanosheet. Each nanosheet stack has a bottom sacrificial layer formed on top of the substrate. The bottom sacrificial layer has a first end and a second end, which are recessed from the first and second ends of the first nanosheet. The semiconductor also has a source or drain (S/D) structures formed in contact with the first end and the second end of the first nanosheet. The S/D structures are isolated from the substrate by the bottom sacrificial layer.