Measurement of '1/f' noise in narrow poly-silicon emitter bipolar transistor structures

We present here our initial findings on low frequency noise measurements for shallow emitter polysilicon contacted transistors. Structures from two particular GEC Plessey Semiconductors' technologies were selected for measurement, to assess the change in low frequency noise performance and modelling issues as bipolar technologies move to ever shallower emitter junctions and smaller emitter windows. We also demonstrate an alternative approach to the problem of identifying the intrinsic corner frequency. Details of our measurement technique are given along with the results of some simulations based on SPICE coefficients extracted from these measurements.