CHARACTERIZING III-V HETEROEPITAXIAL STRUCTURES

A complementary characterization scheme for high-volume production of III-V heteroepitaxial structures is described, focusing on the cost-ef fectiveness and utility of the techniques. AlGaAs/InGaAs/GaAs heteroep itaxial layers grown by molecular beam epitaxy were studied by cross-s ectional transmission electron microscopy (TEM) and photoluminescence (PL) techniques. The presence of a range of layer thicknesses, fine pe riodic striation contrast due to Al composition variations, and layer contrasts in the lattice images observed by TEM in selected samples ar e discussed. The utility of room-temperature PL characterization for A lGaAs/InGaAs/GaAs heteroepitaxial layers is presented. Measures of lay er thicknesses and alloy content as well as overall psuedomorphic high -electron-mobility transistor quality and channel sheet charge are der ived from the PL signatures.