A Dynamic Model of Gold/Platinum Doped Devices

Deep impurities like gold or platinum are extensively used in semiconductor technology to improve the switching characteristics of the devices by decreasing the carrier lifetimes. This, on the other hand, has the undesired effect of increasing the material resistivity. Here a complete model is presented, describing the effects of gold/platinum doping on both the steady-state and transient characteristics. While in steady-state the deep-impurity effects are accounted for by simply redefining the generation-recombination rate, in transient conditions two more continuity equations are necessary to account for the dynamic variation of the charge trapped by the deep levels. Such model is applied here to predict the switching of a platinum-doped diode and the increase in the bulk material resistivity, and shows good agreement with experimental results.