Modification of metal Schottky contacts on silicon by ion implantation

The effect of Ar + and Si + ion irradiation on the Schottky diode characteristics of Al, Ni and Au contacts on (100) n-Si single crystals was studied by I− V measurements. These characteristics were quantified in terms of the ideality factor, the Schottky barrier height, the saturation current and the series resistance. The doses used were all in the range of 1 × 10 15 −1 × 10 16 cm −2. These rather high doses caused most of the Schottky parameters to converge to saturation values after implantation. From α-particle channeling it was ascertained that the implantation caused severe damage in the silicon substrate. This damage was attributed to be the main cause for the measured increase in the series resistance. Auger depth profiling and Rutherford backscattering showed significant mixing in the Ni/Si and Au/Si systems, while only very little mixing was observed in the Al/Si system.