ABSTRACT
A Y-shaped 0.14 μm gate AlGaAs/InGaAs HJFET has been developed using a direct SiO2 opening technology which consists of two step dry-etching with chemically amplified resist mask. A small deviation of 10 nm in Lg was obtained for 0.14 μm gate on 4-inch wafers and standard deviation of Vth achieved was 55 mV. The distance between the top of the gate and the recess surface (hg) was simulated using a two-dimensional device simulator in order to investigate the relation between hg and a fringing gate to drain capacitance. As the result, the fabricated HJFET showed extremely high gain performance of 13dB MSG at 60 GHz.
