Effect of high density H2 plasmas on InGaP/GaAs and AlGaAs/GaAs HEMTs

InGaP/GaAs and AlGaAs/GaAs high electron mobility transistors have been exposed to inductively coupled plasma or electron cyclotron resonance H-2 plasmas as a function of pressure; source power and rf chuck power. The transconductance, gate ideality factor and saturated drain-source current are all degraded by the plasma treatment. Two mechanisms are identified: passivation of Si dopants in the InGaP or AlGaAs donor layers by H-o and lattice disorder created by H+ and H-2(+) ion bombardment. HEMTs are found to be more susceptible to plasma-induced degradation than heterojunction bipolar transistors. Published by Elsevier Science Ltd. All rights reserved.