Experimental Investigation on the Leakage Reverse Current Component Flowing at the Semiconductor PN Junction Periphery

Due to high level of the leakage reverse current, commercial power silicon diodes available at this time have no specification in the data sheets for operation above 200 degC junction temperature. An experimental method is presented to extract information about the uniformity of the reverse current flow over the silicon die area. The power diode with copper attached heat sink is placed in a hot chamber where the temperature is set, so that the level of reverse current to be enough for heat generation. For the same applied power dissipation at reverse and forward bias, the additional junction temperature increase is monitored by the level of reverse current or by the level of the forward current at constant voltage. Experiments have been performed on commercial silicon diode samples in metallic package. It has been found that the additional junction temperature increase is significantly different, when the same power dissipation is applied at reverse bias and then at forward bias voltage, with the device placed in hot chamber at 200degC or 250 degC, depending on the current level