Characteristics and comparison of In0.49Ga0.51P/InGaAs single and double delta-doped pseudomorphic

The InGaP/InGaAs single and double delta-doped pseudomorphic high electron mobility transistor (delta -PHEMT) grown by low-pressure metal organic chem ical vapor deposition have been fabricated and investigated. Based on the e mployment of the wide-gap InGaP Schottky layer and delta-doped carrier supp lier, the high breakdown voltages together with good device characteristics are obtained simultaneously. Furthermore, the newly designed V-shaped InGa As channel can enhance the earlier confinement effect and increase the prod uct of carrier concentration and mobility. Experimentally, for 1 x 100 mum( 2) devices. the gate-to-drain breakdown voltages larger than 40 (30) V, the transconductances of 90 (201) mS/mm, and the maximum current densities of 646 (846) mA/mm are achieved for the studied single and double delta -PHEMT , respectively. Meanwhile, the measured f(T) and f(max) are 12 (16) and 28. 4 (34) GHz, respectively. (C) 2001 Elsevier Science Ltd. All rights reserve d.