AIRBRIDGED-GATE MESFETS FABRICATED BY ISOTROPIC REACTIVE ION ETCHING

We have designed, fabricated, and characterized 0.1 mum gate length ME SFET's in which isotropic BCl3 reactive ion etching is used to remove material under the gate feed to form an airbridge and isolate the acti ve area. This etching is more controllable than wet etch techniques no w used. For comparison, conventional mesa isolated MESFET's were fabri cated on the same wafer. By measuring the RF properties at several bia s points, fringing capacitances have been extracted. The parasitic cap acitances are smaller in the airbridged-gate configuration.