Application of reactive-ion-beam etching to recessed-gate GaAs metal–semiconductor field-effect transistors

Abstract

Dry-recess etching for GaAs metal–semiconductor field-effect transistors (MESFETs) is developed using reactive-ion-beam etching (RIBE) with the etching gas of BCl3. Barrier height and ideality factor of the diode on 200 V bias-voltage RIBE-etched surface are 0.8 and 1.2 V, respectively, after 400 °C annealing. The damage layer caused by RIBE is very thin and there is no evidence of any influence on field-effect transistor (FET) characteristics, using RIBE for recess etching. A 0.4-μm-gate length recessed-gate MESFET is successfully fabricated with transconductance of 140 mS/mm. Uniformities of the threshold voltage, saturation current, and transconductance are improved, compared to those for a wet-chemical recess-etched FET.