Modelling and characterization of the reverse recovery of a high-power GaAs Schottky diode

The reverse recovery characteristics of high-power GaAs Schottky rectifiers are reported at various temperatures; mixed device and circuit simulations were used to study the internal plasma dynamics during the reverse recovery process. In this approach, semiconductor transport and heat generation and diffusion equations were solved self-consistently using a two-dimensional (2-D) finite element grid structure under boundary conditions imposed by the measurement circuit. The simulation results are shown to be in good agreement with the measured data at temperatures in the range of 25°C to 125°C. These results are compared with the reverse recovery characteristics of a commercial silicon PIN power rectifier under identical conditions and it is shown that carrier depletion is the dominant mechanism causing the reverse recovery in a GaAs Schottky diode. The reverse recovery power loss is negligible in a GaAs Schottky rectifier and is shown to decrease as the case temperature is increased, contrary to the silicon PIN rectifier behaviour