Crossing Point Current of Electron and Proton Irradiated Power P-i-N Diodes

The crossing point current of forward I-V curves (IXing) at 25 and 125 C was measured and simulated for 4.5kV/320A silicon power P-i-N diode irradiated by electron, proton and combined electron-proton irradiation. The proton and electron irradiation are shown eto decrease the magnitude of IXing which is beneficial for paralleling of diodes under surge conditions. With increasing irradiation dose this effect saturates. High doses of combined electron-proton treatment can even lead to an increased magnitude of IXing above that of the unirradiated device. To achieve agreement of electro-thermal simulation with experiment, temperature dependence of the capture cross sections σn and σp of the deep level dominant in condition of heavy injection had to be taken into account. With the aid of simulation, the dependencies IXing vs. dose are explained.