InP/InGaAs HBT's have demonstrated very good high-frequency/speed performance [1] and have received a great deal of study for optical front-ends and both analog as well as digital applications. The sensitivity of optical receivers, the noise content of amplifying modules and the noise of signal sources can be severely limited by low frequency noise including 1/f, and trap related noise. Minimization of such noise can only be accomplished by understanding the noise mechanisms present in the device. Numerous studies have been done on AlGaAs/GaAs HBT's [2], [3], however little work has been done on InGaAs/InP HBT's. This paper addresses the low frequency noise characteristics of InGaAs/InP HBT's. To this end, results of systematic frequency, bias, and geometry studies of the base and collector noise spectra are presented.
