The blocking leakage current of packaged silicon devices after their storage at 250 °C ambient temperature

Samples of commercial packaged silicon devices (diodes, thyristors, power MOSFETs) have been stored at 250degC ambient temperature for durations of 4 up to 100 hours. Comparisons of electrical characteristics measured before and after storage at this temperature revealed significant change in the level of the blocking leakage current for PN junctions with organic material passivation. The measured electrical characteristics with significant increase or decrease in the leakage current level provide useful information for the leakage current flow at the junction periphery. Linearity on a portion of electrical characteristic with deviation from this at higher applied voltage is revealed for dominant leakage current at the junction edge. Inorganic dielectric passivated junctions with stable leakage current after storage at high temperature have a current level comparable with the increased current after storage from similar junctions passivated with silicone rubber (organic material). Because of significant leakage current at the junction edge, stable electric characteristics during and after storage at high temperature can become unstable when bias voltage is applied. Reliable operation of silicon devices above the known limit of 150-200degC is possible by further reduction of the leakage current flow through the silicon-passivating dielectric interface existing at the PN junction periphery.