Characteristics of all-OMCVD Grown GaAs MESFETS on Si Substrates

Abstract

ABSTRACTWe present DC characteristics of all-OMCVD grown GaAs MESFET structures on Si substrates with unintentionally doped GaAs or AlGaAs buffer layers. MESFETs fabricated in two and three inch GaAs on Si wafers pinch off well and exhibit reasonably high transconductances up to 110 mS/mm for 1 μm gate devices. The reverse Schottky breakdown voltage of the MESFET gate is as high as 15 V and the forward turn on voltage is ∼0.65 V. The ohmic isolation is comparable to the typical homoepitaxial layer with a leakage current of 100 nA at a 1 V bias. The low background doping levels of unintentionally doped GaAs buffer layers is the key factor for this successful MESFET operation.