Small signal modeling of HEMTs AlGaN/GaN/SiC for sensor and high-temperature applications

Abstract

Thermal and small-signal model parameters analysis have been carried out on 0.25 mm×(2×140μm) AlGaN/GaN HEMT grown on SiC substrate. Two different technologies are investigated in order to establish a detailed understanding of their capabilities in terms of frequency and passivation using on-wafer S-parameter measurement at the temperature 300K.The knowledge of the elements in the small-signal equivalent circuit of such devices is crucial for a reliable design analog circuit; this paper contains the results of the application an improved method for the extraction of intrinsic and extrinsic parameters of the small-signal model from S-parameter measurements on a silicon carbide substrate and the influence of passivation on these parameters. The result provides some valuable insights for future design optimizations of advanced GaN technology.