(InP) HEMT Small-Signal Equivalent-Circuit Extraction as a Function of Temperature

HEMT small-signal equivalent-circuit (SSEC) extractions are of great utility in device characterization, as well as in the design of low-noise amplifiers. Despite the importance of low-noise HEMTs in cryogenic applications, the literature shows little or no work on the temperature dependence of SSEC extractions. This work addresses the question in detail. We recently reported a robust nondestructive accurate room-temperature extraction procedure that we presently apply to InP HEMTs between 5 and 350 K. The extracted SSEC reproduces measured S-parameters well as a function of temperature without the need for optimization. As well, extrinsic resistance and inductive element values exhibit physically correct temperature variations and thereby support the suitability of the present procedure down to cryogenic temperatures. Our work provides a detailed characterization of HEMT SSEC extractions over the broadest temperature range published to date.