Normally-off InGaAs junction field-effect transistor with InGaAs buffer layer

Abstract

InGaAs junction field-effect transistors (JFET's) with 1-µm gate length were successfully fabricated with an n+-InGaAs active layer (8 × 1016cm-3) and an undoped InGaAs buffer layer grown on semi-insulating InP:Fe substrate by liquid-phase epitaxy. The device showed good pinch-off behavior with a threshold voltage of 0.25 V, a low drain current of 1 µA at zero gate-source voltage, and a very high transconductance of 553 mS/mm at room temperature. This is one of the highest transconductance values ever reported for a 1-µm gate-length FET.