Epitaxial growth of AlxGa1−xAs by low-pressure MOCVD

Abstract

Epitaxial layers of AlxGa1−xAs grown from trimethylaluminum, trimethylgallium, and arsine in a low-pressure (10 Torr) MOCVD system were examined by Hall coefficient and photoluminescence measurements. The carrier concentration of undoped n-type AlxGa1−xAs increases as the V/III ratio and/or growth temperature increases. The carrier concentration of p-type epilayers decreases with increasing V/III ratio. The emission peak intensity from near-band transitions at room temperature increases with increasing growth temperature when epilayers are grown from the same source materials. It should be noticed that the peak intensity of AlxGa1−xAs layers grown from different arsine cylinders varied significantly. The origins will be discussed. Ten Torr low-pressure MOCVD can provide high-quality AlxGa1−xAs epilayers which are comparable to the best values reported for layers grown at atmospheric pressure.