Parameter Sensitivities for Hardness Assurance: Displacement Effects in Bipolar Transistors

A model of the dependence of displacement damage in bipolar transistors on material parameters can be used to predict worst-case displacement damage constants for transistors. Many real-device complexities, such as parasitic capacitances, some emitter-crowding effects, unknown base grading, can be eliminated by a worst-case approach. The resulting worst-case damage constant for a 2N914 transistor is near the value extrapolated from statistical test data.