A statistical tool for probing the coupling between noisy traps in semiconductor devices, with application to 1/f noise in SiGe HBTs

We have analyzed random telegraph signal noise in the base current of a silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) from a commercial SiGe HBT technology. We use higher order statistics to test for non-linear coupling between frequency components in the noise signal. We have decomposed the time series into a multilevel random telegraph signal (RTS) and the remaining noise. The random telegraph signal is found to contribute with Lorentzian 1/f/sup 2/-shaped spectra. We show that the non-linear coupling found is directly connected to the random telegraph signal part of the noise.