Study of a high-barrier-gate pseudomorphic transistor with a step-compositioned channel and bottomside delta-doped sheet structure

A newly designed high-barrier-gate Ga0.51In0.49P/InxGa1-xAs/GaAs pseudomorphic transistor with a step-compositioned channel (SC2) and bottomside delta-doped sheet ((BDS)-S-2) structure has been fabricated successfully and studied. For a 1 x 100 mu m(2) studied device, a high gate-to-drain breakdown voltage over 30 V is found. In addition, an available output current density up to 826 mA mm(-1) at a high gate voltage of 2.5 V, a maximum transconductance of 201 mS mm(-1) with a very broad transconductance operation regime of 3 V of gate bias (565 mA mm(-1) of drain current density) and a high de gain ratio of 575 are obtained, simultaneously. Meanwhile, the maximum values of the unity current-gain cut-off frequency f(T) and oscillation frequency f(max) are 16 and 34 GHz, respectively.