A WSi/TiN/Au Gate Self-Aligned GaAs MESFET with Selectively Grown n⁺-Layer using MOCVD

A WSi/TiN/Au gate self-aligned GaAs MESFET was formed using MOCVD. The WSi/TiN/Au gate acts as a selective growth mask for the n + -layer. This new process is demonstrated to be effective for reducing the gate resistance and source resistance of FETs simultaneously. The gate resistance, R g , was 3.4 Ω ( L g =1.3 um, W g =30 um) and was reduced one tenth compared to that of the WSi gate. A high-speed MSI and high performance microwave device can be obtained by using the WSi/TiN/Au gate self-aligned GaAs MESFETs.