Physical origins of burst noise in transistors

Burst noise in bipolar junction transistors has been attributed to leakage current through crystallographic defects located in proximity to the base-emitter junction. The current is modulated by the random occupancy of a single flaw located near the defects. The previous theoretical work has only described defects located in the emitter-base space-charge region away from the surface. This paper extends the noise model to include the regions close to the surface where the high incidence of defects makes burst noise sources more likely. Experimental data is presented on typical devices, some of which were gold doped. The proposed model is in agreement with all experimental measurements. The data, in conjunction with the noise model, is used to determine physical parameters such as capture cross sections and energy level of the flaw which correlate well with published values. The investigation suggests several techniques which are useful in reducing the incidence ot burst noise.