HIGH TRANSCONDUCTANCE GaAs MESFET WITH REDUCED SHORT CHANNEL EFFECT CHARACTERISTICS.

A high g//m , 375 mS/mm (V//t //h equals -0. 09 V), has been achieved from a 0. 3- mu m long gate GaAs MESFET with a very small short channel effect by using an MBE grown channel layer. The maximum K-value obtained was 410 mS/Vmm, which is the highest ever reported for GaAs MESFETs. A technology combining sidewall-assisted self-alignment technology (SWAT) and refractory metal gate n** plus selective ion implantation was successfully applied to the fabrication of a GaAs MESFET with MBE grown channel layer, resulting in a very low source series resistance of 0. 3 OMEGA mm. FET characteristic dependences on gate length were also compared for FETs with different doping concentrations. The highly doped channel turned out to be effective in reducing the short-channel effects and improving the FET load drivability.