Comparison of gold, platinum, and electron irradiation for controlling lifetime in power rectifiers

Recombination statistics based upon a single dominant level have been used to predict the relative characteristics of gold-diffused, platinum-diffused, and electron-irradiated silicon power rectifiers and thyristors. These calculations indicate that gold-diffused devices will have the best trade-off curve between forward voltage drop and reverse recovery time, while exhibiting the highest leakage currents. Electron-irradiated devices are predicted to have the worst trade-off curve among the three cases and twice the leakage current of platinum-diffused devices. The leakage current of platinum-diffused devices is shown to be an order of magnitude lower than gold-diffused devices. The measured characteristics of gold-diffused, platinum-diffused, and electron-irradiated power rectifiers are shown to be in good agreement with these calculations. The results are also shown to be applicable to power thyristors.