High-current lattice-strained In0.59Ga0.41As/In0.52Al0.48As modulation-doped field-effect transistors grown by molecular beam epitaxy

High-current driving capability is realized in submicron-gate lattice-strained In0.59Ga0.41As/In0.52Al0.48As (Δa/a=4×10−3) modulation-doped field-effect transistors. Full-channel drain current in excess of 1.10 and 1.90 A/mm are obtained at 80 K for the singly doped and doubly doped structure, respectively. By using the double modulation technique and a buried p-buffer layer, excellent high-frequency performance and flat transconductance characteristics were realized over a very broad range of gate and drain bias voltages. These devices are very suitable for large-signal or power device operations. The high quality In0.52Al0.48As buffer layer eliminates the hysteresis and current instability (or the kink effect) in submicron-gate devices at both 300 and 80 K.