DYNAMIC HIGH-CURRENT STRESSING DAMAGE AND POSTSTRESS RELAXATION IN P-N-P SILICON BIPOLAR JUNCTION TRANSISTORS

The degradation of p-n-p silicon BJTs under dynamic high-current stres s has been studied. The BJTs were biased in the forward active mode wi th collector open or shorted to the base, and in the inverse active mo de with emitter open or shorted to the base, the bias voltages were va ried. During stress, the phenomena of reduction and recovery in base c urrent have been found. When the BJT was biased in the inverse active mode, after the stress was terminated, the base current continued to i ncrease with measurement time. This post-stress degradation takes seve ral hours to reach a saturation value. Possible physical mechanisms ha ve been proposed to interpret the experimental findings in this work.