Performance of Inverted Structure Modulation Doped Schottky Barrier Field Effect Transistors

Inverted structure (Al, Ga)As/GaAs modulation doped Schottky barrier FETs were fabricated. The structures from which the FETs were prepared were grown by molecular beam epitaxy. These FETs are easier to fabricate than normal MD FETs, because the rectifying metal contact is made to GaAs rather than to (Al, Ga)As. Having the GaAs on top of the (Al, Ga)As also makes these devices less susceptible to degradation. Although the device structure is not yet fully optimized, normalized transconductances of 70 mS/mm and excellent saturation characteristics have been obtained.