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 GaA s complementary ICs is proposed. The device is a doped-channel metal-i nsulator-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 meta lorganic molecular beam epitaxy (MOMBE) to reduce parasitic resistance . The 0.5 mu m 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 Omega mm is half of that for a device structure witho ut selectively grown contact layers. Moreover, performances of GaAs co mplementary ICs, using this p-channel HJFET and a previously reported 0.5 mu m n-channel HJFET, are estimated by SPICE. As a result, a propa gation delay of 120 ps and a power dissipation of 0.08 mu W MHz(-1) ga te(-1) at a 1.0 V supply voltage are predicted. (C) 1998 Published by Elsevier,Science Ltd, All rights reserved.