ABSTRACT
Ohmic metal self-aligned gate (OMEGA) process has been developed in order to achieve a low knee voltage in GaAs MISFETs. The gate metal is self-aligned to the drain and source ohmic metal which is made of WSi and is formed on a thick n+-GaAs/n+-InGaAs cap layer. The distance between the gate metal and the drain/source metal is minimized by using this process, and consequently the parasitic resistances from drain to source can be drastically reduced. The OMEGA FET shows a low knee voltage of 0.8 V with a high breakdown voltage of 12 V. These features indicate that the new FET is highly suitable for power applications under low supply voltage and consequently contributes to minimize the battery cell and the size of microwave mobile communication systems.
