A comparison of low-frequency noise characteristics and noise sources in NPN and PNP InP-based heterojunction bipolar transistors
Article
Hsu, SSH, Pavlidis, D. (2003). A comparison of low-frequency noise characteristics and noise sources in NPN and PNP InP-based heterojunction bipolar transistors
. IEEE TRANSACTIONS ON ELECTRON DEVICES, 50(9), 1974-1982. 10.1109/TED.2003.815367
Hsu, SSH, Pavlidis, D. (2003). A comparison of low-frequency noise characteristics and noise sources in NPN and PNP InP-based heterojunction bipolar transistors
. IEEE TRANSACTIONS ON ELECTRON DEVICES, 50(9), 1974-1982. 10.1109/TED.2003.815367
Low-frequency noise characteristics of NPN and PNP InP-based heterojunction bipolar transistors (HBTs) were investigated. NPN HBTs showed a lower base noise current level (3.85 × 10-17 A2/Hz) than PNP HBTs (3.10 × 10-16 A2/Hz), but higher collector noise current level (7.16 × 10-16 A2/Hz) than PNP HBTs (1.48 × 10-16 A2/Hz) at 10 Hz under IC = 1 mA, VC = 1 V. The NPN devices showed a weak dependence IC0.77 of the collector noise current, and a dependence IB1.18 of the base noise current, while the PNP devices showed dependences IC1.92 and IB1.54, respectively. The dominant noise sources and relative intrinsic noise strength were found in both NPN and PNP InP-based HBTs by comparing the noise spectral density with and without the emitter feedback resistor. Equivalent circuit models were employed and intrinsic noise sources were extracted. The high base noise current of PNP HBTs could be attributed to the exposed emitter periphery and higher electron surface recombination velocity in P-type InP materials, while the relatively high collector noise current of NPN HBTs may be due to the noise source originating from generation-recombination process in the bulk material between the emitter and the collector.
