Investigation of MBE grown GaAs/AlGaAs/InGaAs heterostructures

This paper reports on the influence of the In mole fraction variation (0.1≤x≤0.25) of MBE grown pseudomorphic GaAs/AlyGa1−yAs/InxGa1−xAs heterostructures on the material quality and the performance of the fabricated devices. For x=0.1–0.15, the carrier mobility in the samples was 4500 cm2 V−1 s (at 300 K) and 37 000 cm2V−1 s (at 77 K) and decreased significantly at low temperatures as x was increasing up to 0.25. Transistors with gate length of 0.8 m and In0.1Ga0.9As channels exhibited transconductances of 200–220 mSm mm−1 and output conductances of 0.15–0.20 mSm mm−1, while gate-source breakdown voltages were 27–28 V. Delay times of the designed and fabricated ICs frequency dividers by 2 were 130–140 ps.