Experimental Drain I-V Characteristics of Power MOS Transistors and the Nature of Reverse Leakage Current of Oxide Passivated PN Junctions

Drain electrical characteristics for a 10 A and 400V MOS transistor have been measured and analyzed. At junction temperature as high as 200 degC and above this value, accentuated rise of the drain reverse (blocking) current takes place before the specified voltage of 400 V is reached, due to current leakage at the cells junction edge. Observed constant drain current, attributed to a primary diffusion current component is not undoubted evidence for the location of this current in the junction bulk. Similar behavior is observed when bias voltage below the threshold voltage is applied on the gate. Oxide-passivated junctions from bipolar devices may behave like those from MOSFETs at high temperature