High-transconductance InAs/AlSb heterojunction field-effect transistors with delta -doped AlSb upper barriers

The authors report the fabrication and temperature-dependent characterization of InAs/AlSb quantum-well heterojunction field-effect transistors (HFETs). Devices with electron sheet concentrations of 3.8*10/sup 12/ cm/sup -2/ and low-field electron mobilities of 21000 cm/sup 2//V-s have been realized through the use of Te delta -doping sheets in the upper AlSb barrier. One device with a 2.0- mu m gate length showed a peak extrinsic transconductance of 473 mS/mm at room temperature. Gate leakage current, operating current density, and extrinsic transconductance were found to decrease with decreasing temperature.<
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