Low Frequency Noise of InP/InGaAs Heterojunction Bipolar Transistors

Abstract

In this paper, we have studied the 1/f low frequency noise of self-aligned and non self-aligned InP/InGaAs heterojunction bipolar transistors (HBTs). The total noise of transistor is modeled by two current noise sources. The evolution with geometry, technological process and bias, of the current spectral densities referred to the input and output of the devices, permit us to locate the noise sources. Noise is mainly generated in the intrinsic transistor, and an extra noise perimetric source has been identified for the self-aligned transistors at the emitter periphery.

A comparison of low-frequency noise characteristics and noise sources in NPN and PNP InP-based heterojunction bipolar transistors

“…6 shows the low-frequency noise of the NPN and PNP InP-based HBTs in this work, and also compares several results found in literature [8], [23], [24]. The results shown were obtained from a 5-m diameter InP/InGaAs NPN HBT [8], a 21 m emitter InAlAs/InGaAs HBT [23], and a 22 m emitter self-aligned InP/InGaAs HBT [24]. As can be seen, the base noise levels of InP/InGaAs NPN HBTs in this study are comparable to [24] and slightly lower than [23] under similar base current levels.…”

“…The results shown were obtained from a 5-m diameter InP/InGaAs NPN HBT [8], a 21 m emitter InAlAs/InGaAs HBT [23], and a 22 m emitter self-aligned InP/InGaAs HBT [24]. As can be seen, the base noise levels of InP/InGaAs NPN HBTs in this study are comparable to [24] and slightly lower than [23] under similar base current levels. Compared to the results in [8], the noise levels reported here seem to be high under low base current levels, however, if one extrapolates the curve plotted from [8] up to above 200 A, similar noise levels can be obtained.…”