GaAs power m.e.s.f.e.t.s. with a graded recess structure

A new recess structure device was developed to improve the field distrubution and therfore the performance of GaAs power m.e.s.f.e.t.s. The linear gain and the output power were improved by 1?2 dB for this structure. The highest output powers obtained are 15 W with 4 dB associated gain at 6 GHz, and 4.3 W with 3 dB associated gain at 11 GHz.     

High speed normally-off GaAs MESFET integrated circuit

Normally-off GaAs MESFET integrated circuits with a maximum toggle frequency of 2.4 GHz were fabricated by conventional photolithography. The unfavourable effect of the surface depletion layer due to the large state density at the GaAs surface has been reduced by adopting the recessed gate FET structure.     

Ion-implanted E/D-type GaAs IC technology

An enhancement/depletion-type GaAs MESFET IC technology has been developed using selective ion implantation into SI GaAs. By reducing the source-gate and the drain-gate spacings down to about 0.4 ?m, the unfavourable effect of the surface state1 was effectively lowered, while guaranteeing sufficient breakdown voltages. The minimum propagation delay of 66 ps was achieved in a 15-stage ring oscillator with 1.2 ?m-long gate FETs.