Evaluation of effective electron velocity in AlGaN/GaNHEMTs

Abstract
The authors have fabricated a 1.3 µm-long gate AlGaN/GaN HEMT with fT of 14.1 GHz, corresponding to a high fT × gate-length product of 18.3 GHz·µm. By analysing the relationship between the delay time and the inverse of the drain current, the effective electron velocity in the channel was evaluated to be as high as 1.2 × 107 cm/s.