High breakdown voltage, sub-micron, strained InGaAlAs/GaAs FET's

Submicron gate GaAs FETs with a pseudomorphic surface layer of InGaAlAs used to increase breakdown voltage have been fabricated. A 0.2- mu m gate length device with f/sub max/ of 80 GHz had a saturation current of 360 mA/mm and a gate-to-drain breakdown of 11.5 V. The effect upon device performance of gate length, source-to-drain spacing and Al mole fraction was also investigated. The breakdown voltage showed only small changes with changes in gate length at submicron dimensions. The source-to-drain spacing changed not only the breakdown voltage but also appeared to change the mechanism that limits high-voltage performance.< >