0.20 mu m pseudomorphic HEMT device fabricated by PSM and self-aligned head T-shaped gate techniques

Abstract

We propose a new optical lithographic technique to form 0.20 mu m length T-shaped gate for application to low noise high electron mobility transistor (HEMT). By using this technique, 0.20 mu m AlGaAs/InGaAs/GaAs pseudomorphic HEMT (PHEMT) was successfully fabricated. and the transconductance of 498 mS/mm and the cutoff frequency of 62.4 GHz were obtained, which are the best values ever reported for the HEMTs fabricated using optical lithography.