Decreased low frequency noise by hydrogen passivation of polysilicon emitter bipolar transistors

The effect of hydrogen passivation by forming gas annealing (FGA) on the bi polar junction transistor low frequency noise was investigated. The results demonstrated a reduced 1/f noise component by a factor of five after FGA, which resulted in a reduced corner frequency. An equivalent input noise spe ctral density (S-IB) dependence on base current (IB) of S-IB similar to I-B (2) and on emitter area (A(E)) of S-IB similar to A(E)(-1) was observed, bo th before and after FGA. The interpretations of the results were (a) the 1/ f noise was due to carrier number fluctuation, (b) the noise sources were h omogeneously distributed over the polysilicon/monosilicon emitter interfaci al oxide, and (c) the noise sources were passivated by hydrogen. (C) 2000 E lsevier Science Ltd. All rights reserved.