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/Al_yGa_1?yAs/In_xGa_1?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 In_0.1Ga_0.9As 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.