Pseudomorphic In x Ga 1-x As/In y Al 1-y As high-electron mobility transistor structures grown by solid source molecular beam epitaxy

Abstract

ABSTRACTWe report on the optimization of InP-based InGaiAs/InA11As pseudomorphic high electron mobility transistor (PHEMT) structures to achieve the highest possible two-dimensional electron gas (2DEG) density and mobility. Using ouroptimized growth conditions, high 2DEG concentration and mobility products have been obtained. The single-side-dopedPHEMT structure with a s-doping concentration of 6 x 1012 cm2 gives a 2DEG sheet density of 3.93 x 1012 cm2 with amobility of 1 1 100 cm2/V.s. The double-side-doped PHEMT structure with a bottom 6-doping concentration of 1 x 1012 cm2and a top s-doping concentration of 5 x 1012 cm2 gives a 2DEG sheet density of4.57 x 1012 cm2 with a mobility of 10900cm2/V.s. The structural properties of the PHEMT structures are characterized by XRD measurements. Preliminary deviceresults are also reported.Keywords: InGaAs/InAlAs, HEMT, SSMBE, XRD, Hall. 1. INTRODUCTION InGa1As/InAl1As pseudomorphic high electron mobility transistors (PHEMT's) have demonstrated the highest cut-off