Growth and Characterization of Epitaxial GaAs Deposited by Plasma-Enhanced Metal-Organic Chemical Vapor Deposition

Abstract

ABSTRACTEpitaxial GaAs films have been deposited using a Plasma-Enhanced Metal Organic Chemical Vapor Deposition (PE-MOCVD) technique. This technique uses an RF discharge to dissociate arsine and hydrogen upstream from the substrate. The plasma increases the partial pressure of arsenic above the substrate and improves the growth and quality of GaAs films grown at low teyperature and with low arsine flow rates. We have used photoluminescence, Hall measurements, dislocation etches, and transmission electron microscopy (TEM) to study the properties of films grown with and without plasma. enhancement under a variety of reactor conditions. Specular epitaxial layers of n-GaAs were grown with and without plastua at, very low pressures (2 – 3 Torr) on semiinsulating GaAs substrates. Layers grown both with and without the plasma showed good mobility and photoluminescence at deposition temperatures of 650°C. At lower deposition temperatures the films deposited with the plasma were better than those deposited without the plasma. A KOH-NaOH eutectic etch revealed a better structural quality in films deposited with plasma at low arsine partial pressure.