AVALANCHE INJECTION IN HIGH-VOLTAGE SI PIN DIODES

An experimental technique using optical excitation by a YAG laser puls e for studying avalanche injection in power devices is demonstrated Th is technique enables the creation of high uniform excess carrier conce ntrations in an optically defined device volume, involving very little heating. A method for determining the onset of avalanche multiplicati on, by studying the time integral of the reverse recovery current, is proposed. A PiN diode is observed to turn off from avalanching at a di ssipated power density of more than 200 kW/cm(2).