Dopant-Segregated Schottky Source/Drain FinFET With a NiSi FUSI Gate and Reduced Leakage Current

Enhanced Dopant-segregated Schottky-barrier (DSSB) FinFETs combined with a fully silicided (FUSI) gate were fabricated via single-step Ni-silicidation. Both workfunction control of the gate and a lowered effective SB-height in the source/drain junctions are simultaneously achieved by the dopant-segregated silicidation process. Moreover, the leakage current was significantly reduced with the aid of deep source/drain implantation. Therefore, it can be expected that a DSSB device with a FUSI gate have several advantages as both a logic and nonvolatile memory device. First, for a logic device, it can provide low parasitic resistance and a tunable threshold voltage. Second, for a nonvolatile memory device, the increased workfunction due to the FUSI gate can enhance the erasing characteristics by suppressing the back tunneling of electrons from the gate side as well as the programming characteristics.