DC and RF characteristics of 0.25 µm non-recessedgate GaAs P-HEMTfabricated by self-aligned gate process

Abstract

A 0.25 µm non-recessed gate GaAs P-HEMT has been fabricated by using a self-aligned gate process and Pd/Ni/Ge ohmic contact. Despite the non-recessed gate structure, the device showed excellent DC and RF characteristics (average gm,max = 395 mS/mm, fT = 75 GHz and fmax = 190 GHz) with a considerable improvement in device yield and uniformity. The RF performances of the fabricated device are comparable or even superior to those of previously reported quarter-micrometre recessed gate GaAs P-HEMTs.