Effect of annealing on interface state density of Ni-silicided/Si1−xGex Schottky diode

Nickel-silicided/Si1−xGex Schottky junctions are fabricated by annealing the deposited nickel (Ni) film on relaxed Si0.75Ge0.25 layer at a temperature range of 300-900 °C for 60 s. Energy dispersive spectroscopy (EDS) was used to quantify the Ge composition in silicide/germanosilicide grains, formed during annealing. Schottky barrier height (ΦB) of the silicided diodes was extracted from forward current-voltage (I-V) and capacitance-voltage (C-V) characteristics. The forward I-V characteristics were also simulated for understanding the influence of interfacial layer present at the silicide and Si0.75Ge0.25 interface. The capacitance-voltage method was used to determine the energy distribution of the interface state density (Dit) and was found to decrease with increasing energy from the valence band edge.