NONSTATIONARY 1/F NOISE IN INP/INGAAS HETEROJUNCTION BIPOLAR-TRANSISTORS

1/f noise for most electronic systems is stationary in that repeated measurements of the noise power will give the same result within statistical uncertainty. In contrast, we have observed highly nonstationary 1/f noise in the output current of a series of InP based heterojunction bipolar transistors (HBTs). We have applied higher order statistics to the non-Gaussian fluctuations of these devices to probe the source of the intrinsic 1/f noise. We find signatures of superimposed Lorentzians making up an otherwise featureless 1/f noise spectrum consistent with generation-recombination-type noise in the base-emitter region of the device. The nonstationarity of these devices scales inversely with the device size as would be expected for an intrinsic mechanism. We suggest that these techniques may be utilized to a greater extent in the future as device sizes are reduced. © 1995 American Institute of Physics.