The effect of OMCVD (Organometallic Chemical Vapor Deposition) reactor renovations on GaAs epilayer growth

A major redesign and rebuilding of The Aerospace Corporation's Organometallic Chemical Vapor Deposition (OMCVD) reactor has been carried out. The entire gas-handling system was redesigned and replaced in order to reduce gas contamination, and new high-precision mass flow controllers and temperature baths were installed. Carrier gas flow through the organometallic bubblers was modified for improved safety and reliability, and gas lines that allow for the utilization of several different organometallic gallium and arsenic sources were also installed. Gallium arsenide (GaAs) epilayers grown using trimethylgallium (Me3Ga) and arsine (AsH3) in this reactor system following its renovation have consistently exhibited purity levels that are significantly higher than those of epilayers previously grown at The Aerospace Corporation. Epitaxial GaAs films (-4 microm thick) with excellent surface morphologies have been obtained which exhibit carrier concentrations of 3 x 10 14/cm to the 3rd power and 77 K mobilities of approximately 68,000 sq. cm/V-s. These physical and electrical characteristics are representative of state-of-the-art unintentionally doped GaAs.