GaAs/(In,Ga)As, p-channel, multiple strained quantum well field-effect transistors with high transconductance and high peak saturated drain current

Abstract

GaAs/In0.2 Ga0.8 As structures with two paralleled 10 nm quantum wells, modulation doped from the top, bottom, and middle with Be, have been fabricated into multiple strained quantum well field-effect transistors (MQWFET’s) with 1×150 μm2 Ti/Au gates and examined both illuminated and in the dark at 300 and 77 K. Measurements on van der Pauw structures fabricated simultaneously with the transistors showed hole mobilities and sheet carrier densities to be 200, 3100, and 8040 cm2/V s, and 5.7×1012, 1.8×1012, and 1.5×1012 cm−2 , at 300, 77, and 4 K, respectively. Shubnikov–de Haas measurements made below 4 K verified the existence of a double-channel two-dimensional hole gas with a strain-shifted light-hole ground state in the quantum wells with an effective hole mass of 0.15 me . A representative p-channel MQWFET showed well-saturated common-source output characteristics, both illuminated and unilluminated, at all measurement temperatures. Measured peak extrinsic transconductances and peak saturated drain currents for the unilluminated 1 μm device were 31 and 60 mS/mm and 27 and 67 mA/mm, at 300 and 77 K, respectively.

Characteristics of a δ -doped GaAs/InGaAs p-channel heterostructure field-effect transistor

“…Among the p-HFETs, GaAs/ InGaAs and AlGaAs/InGaAs strained quantum well structures reveal strain-induced light-hole conduction. 12,13 In this letter, to avoid the DX centers in higher composition AlGaAs epilayers and the lower doping efficiency of AlGaAs than GaAs, we demonstrate a ␦-doped GaAs/InGaAs p-HFET grown by low-pressure metalorganic chemical vapor deposition ͑LP-MOCVD͒. High two-dimensional hole gas ͑2DHG͒ concentrations are achieved by using the ␦-doping technique.…”

A new version of the method for analysing peak broadening caused by local tilt distribution in double-crystal X-ray diffraction measurements

“…The strained layer superlattice (SLS) structure has become indispensable in obtaining high-performance optoelectronic devices. The advantages of the SLS have been investigated and demonstrated by applying it to various optoelectronic devices (Osbourn, 1986;Zipperian et al, 1988;Kolbas et al, 1988;Monserrat & Tothill, 1989). For further improvement of device performance, highly strained SLS structures are required.…”

A new method for analysing peak broadening caused by compositional fluctuation in X-ray diffraction measurements

“…MQWs and SLSs have been widely used in laser diodes and optical modulators (Tsang, 1986;Temkin et al, 1985;Wakita et al, 1987;Osbourn, 1986;Sugiura et al, 1995). Strained structures have proven useful in controlling device characteristics (Osbourn, 1986;Zipperian et al, 1988;Kolbas et al, 1988;Monserrat & Tothill, 1989). The control of the polarization dependence in optical devices and the enhancement of carrier mobility in optoelectronic devices are well known examples.…”