Structural Characterization of GaN Grown By Electron Cyclotron Resonance-Metalorganic Molecular Beam Epitaxy (ECR-MOMBE)

ABSTRACTElectron cyclotron resonance-metalorganic molecular beam epitaxy (ECR-MOMBE) has been used to deposit cubic and hexagonal gallium nitride (GaN) on various substrates, namely GaAs, ZnO and Al2O3. This paper will report on the effect of the growth rate of the GaN layer on the surface morphology, as analyzed using scanning electron microscopy (SEM). Structural characterization of this material was conducted using cross-sectional transmission electron microscopy (XTEM) and x-ray diffraction. Conditions such as pre-deposition annealing, growth rate and growth temperature are critical in determining the phase and crystallinity of the deposited layers. These parameters were optimized to obtain the cubic GaN phase on GaAs substrates and single crystal wurtzitic GaN on ZnO and Al2O3 substrates.