A semiconductor structure is provided that includes nanosheet containing devices having a bottom dielectric isolation structure and high quality source/drain (S/D) structures. In the present application, the bottom dielectric isolation structure is formed after the S/D structures to ensure high quality epitaxy for both long channel and short channel nanosheet containing devices. The bottom dielectric isolation structure of the present application has a first portion that is located beneath each nanosheet stack and a second portion that is located in a single diffusion break point trench.