Sub-0.1-eV Effective Schottky-Barrier Height for NiSi on n-Type Si (100) Using Antimony Segregation

We report a new method of forming nickel silicide (NiSi) on n-Si with low contact resistance, which achieves a Schottky barrier height of as low as 0.074 eV. Antimony (Sb) and nickel were introduced simultaneously and annealed to form NiSi on n-Si (100). Sb dopant atoms were found to segregate at the NiSi/Si interface. The devices with Sb segregation show complete nickel monosilicide formation on n-Si (100) and a close-to-unity rectification ratio. The rectification ratio R_c is defined to be the ratio of the forward current to the reverse current, where the forward and reverse currents are measured using forward and reverse bias voltages, respectively, having the same magnitude of 0.5 V. This process is also compatible and easily integrated in a CMOS fabrication process flow.