Low frequency 1/f noise and current gain degradation in BiCMOS n-p-n transistors

The authors report experimental results on the effect of forward current gain (h/sub fe/ degradation on the low-frequency 1/f noise characteristics of polysilicon emitter n-p-n transistors. A direct relationship between progressively increasing levels of h/sub fe/ degradation and changes in the 1/f noise spectra has been observed. Measurement of the base Gummel characteristic and base current dependence of the noise suggests that surface recombination resulting from hot carrier stress degrades h/sub fe/ and is the dominant 1/f noise source. >