High performance HJFET MMIC with embedded gate technology for microwave and millimeter-wave IC's using EB lithography (EMMIE)

A high gain AlGaAs/InGaAs HJFET has been developed with Embedded gate techn ology for Microwave and Millimeter-wave IC's using EB lithography (EMMIE). EMMIE consists of a direct SiO2 opening by two-step dry-etching with a chem ically amplified resist mask. 0.14 mu m gate patterns delineated on 4-inch wafers exhibited a small deviation of 10 nm in L-g and a V-th standard devi ation of 55 mV. The optimum distance between the top of the gate and the re cess surface (h(g)) was determined using a two-dimensional device simulator in order to investigate the effect of fringing gate to drain capacitance o n the RF gain performance. The fabricated one-stage HJFET MMIC amplifier ex hibited extremely high gain performance of 12.4 dB at 76 GHz.