Au/TiN/WSi-gate self-aligned GaAs MESFETs using rapid thermal annealing method

Au/TiN/WSi-gate self-aligned GaAs MESFETs were fabricated using the rapid thermal annealing method to reduce the gate resistance of the FETs. The gate resistance Rg was 4.2 Ω (Lg=1.5 μm, Wg=400 μm), just 1/20 of that of the WSi-gate FET. The maximum frequency of oscillation fmax of the Au/TiN/WSi-gate FETs was improved to be about twice that of WSi-gate FETs.