Fabrication of 0.15-mu m Gamma-shaped gate In0.52Al0.48As/In0.6Ga0.4As metamorphic HEMTs using DUV lithography and tilt dry-etching technique

Abstract

An In0.52Al0.48As/In0.6Ga0.4As metamorphic high-electron mobility transistor (MHEMT) with 0.15-mu m Gamma-shaped gate using deep ultraviolet lithography and tilt dry-etching technique is demonstrated. The developed submicrometer gate technology is simple and of low cost as compared to the conventional E-beam lithography or other hybrid techniques. The gate length is controllable by adjusting the tilt angle during the dry-et ching process. The fabricated 0.15-mu m In0.52Al0.48As/In0.6Ga0.4As MHEMT using this novel technique shows a saturated drain-source current of 680 mA/mm and a transconductance of 728 mS/mm. The f(T) and f(max) of the MHEMT are 130 and 180 GHz, respectively. The developed technique is a promising low-cost alternative to the conventional submicrometer E-beam gate technology used for the fabrication for GaAs MHEMTs and monolithic microwave integrated circuits.