Compositional Variation Related to the Growth Process in GaAlAs Epitaxial Layers

Abstract

Compositional profiles of epitaxial normalGaAlAs layers grown by liquid phase epitaxy using the supersaturation technique were investigated in relation to the growth conditions by laser Raman spectroscopy. In the diffusion limited process with a flat temperature profile during epitaxial growth cycle, a uniform layer of 1.26±0.017 μnormalm false(±1.3%false) with a small compositional variation of 0.457±0.007 false(±1.5%false) can be accomplished. On the other hand, remarkable compositional variations (> ± 10%) occur during an initial growth stage, which depends on the initial supersaturation. Compositional uniformity is improved to 0.152±0.007 false(±4.6%false) by decreasing initial supersaturation to 2.5°C.