Metamorphic In0.3Ga0.7As/In0.29Al 0.71As layer on GaAs: A new structure for high performance high electron mobility transistor realization

Abstract

A new high electron mobility transistor (HEMT) using InAlAs/InGaAs grown on GaAs has been successfully realized. This structure, with an In content close to 30%, presents several advantages over conventional pseudomorphic HEMT on GaAs and lattice matched HEMT on InP. To accommodate the mismatch between the active layer and the GaAs substrate, a metamorphic buffer has been grown. High electron mobility with high two-dimensional electron gas density (20 700 cm 2/V s with 4×1012 cm-2) and high Schottky barrier quality (Vb=0.68 V with η=1.1) have been obtained. A 3 μm gate length device has shown intrinsic transconductance as high as 530 mS/mm.