High Schottky barrier height of Au contact on Si-nanowire arrays with sulfide treatment

We report on the formation of high-barrier Au contact to Si nanowires (SiNWs) with sulfide treatment. The discrepancy in Schottky barrier height (qφ_B) extracted from current-voltage (I-V) and capacitance-voltage (C-V) characteristics was studied. A high qφ_B of 1.03 eV is achieved between the 60 s-sulfide-treated SiNW surface and Au, which is confirmed by C-V measurements. For Au/SiNWs/n-type Si Schottky diodes, qφ_B determined from C-V measurements is higher than that determined from I-V measurements, owing to the image-force lowering and the larger ideality factor than 2. However, for Au/60 s-sulfide-treated SiNWs/n-type Si Schottky diodes, the lower qφ_B determined from I-V measurements than that determined from C-V measurements is attributed to a combined effect of the image-force lowering and the interfacial dipole. Note, a suitable sulfide treatment time is an important issue for producing high-quality Schottky diodes.