Performance of a p-channel heterojunction fet with P⁺ -GaAs selectively grown contact layers for GaAs complementary ICs

A new p-channel heterojunction field-effect transistor (HJFET) for GaAs complementary ICs is proposed. The device is a doped-channel metal-insulator-semiconductor (MIS) structure with an i-AlGaAs barrier layer of high Al mole fraction to suppress gate forward leakage. Its source-drain regions are formed by p⁺ -GaAs layers selectively grown by metalorganic molecular beam epitaxy (MOMBE) to reduce parasitic resistance. The 0.5 μm HJFET exhibits a maximum transconductance of 40 mS mm^-1, a gate leakage turn-on voltage of -1.2 V, a cut-off frequency of 6.8 GHz, and a maximum frequency of oscillation of 8.0 GHz. Its source resistance of 10 Ω mm is half of that for a device structure without selectively grown contact layers. Moreover, performances of GaAs complementary ICs, using this p-channel HJFET and a previously reported 0.5 μm n-channel HJFET, are estimated by SPICE. As a result, a propagation delay of 120 ps and a power dissipation of 0.08 μW MHz^-1 gate^-1 at a 1.0 V supply voltage are predicted.