Epitaxial lift-off GaAs HEMT's

An extensive study of epitaxial lift-off (ELO) Al/sub 0.3/Ga/sub 0.7/As/GaAs modulation doped heterostructure high electron mobility field-effect transistors (HEMT's) is presented. Effects of ELO on electron transport properties of two-dimensional electron gas at AlGaAs/GaAs interface are investigated. An ELO HEMT with 1.5 /spl mu/m gate length had a maximum extrinsic transconductance g/sub m-max/=125 mS/mm, a unity current gain cut-off frequency f/sub t/=10.5 GHz, and a maximum frequency of oscillation f/sub max/=12 GHz. Statistical distributions of maximum intrinsic transconductance of ELO HEMT's are presented and compared with their on-wafer counterparts. Stability of the ELO HEMT's has also been evaluated by continuous operation at room temperature under dc bias.<
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