AlGaAs/GaAs JFETs by organometallic and molecular beam epitaxy

Normally-off and normally-on AlGaAs/GaAs heterojunction gate GaAs FETs (HJFETs) for high-speed logic applications have been fabricated with molecular beam epitaxy (MBE) and organometallic vapor phase epitaxy (OM-VPE). The best normally-off devices used MBE n-GaAs active layers and OM-VPE gate layers of p(+)-AlGaAs and p(+)-GaAs. Saturation currents followed a square law and current scaling constants were the highest on record for HJFETs, greater than 50 microamps/micron-V-squared.