Patent ID: 10644112

Abstract:
A subfin leakage problem with respect to the silicon-germanium (SiGe)/shallow trench isolation (STI) interface can be mitigated with a halo implant. A halo implant is used to form a highly resistive layer. For example, a silicon substrate layer 204 is coupled to a SiGe layer, which is coupled to a germanium (Ge) layer. A gate is disposed on the Ge layer. An implant is implanted in the Ge layer that causes the layer to become more resistive. However, an area does not receive the implant due to being protected (or covered) by the gate. The area remains less resistive than the remainder of the Ge layer. In some embodiments, the resistive area of a Ge layer can be etched and/or an undercuttage (etch undercut or EUC) can be performed to expose the unimplanted Ge area of the Ge layer.