Inverted thin channel mosfet with self-aligned expanded source/drain

Abstract

After formation of a gate electrode, a source trench and a drain trench are formed down to an upper portion of a bottom semiconductor layer having a first semiconductor material of a semiconductor-on-insulator (SOI) substrate. The source trench and the drain trench are filled with at least a second semiconductor material that is different from the first semiconductor material to form source and drain regions. A planarized dielectric layer is formed and a handle substrate is attached over the source and drain regions. The bottom semiconductor layer is removed selective to the second semiconductor material, the buried insulator layer, and a shallow trench isolation structure. The removal of the bottom semiconductor layer exposes a horizontal surface of the buried insulator layer present between source and drain regions on which a conductive material layer is formed as a back gate electrode.