Influence of Ga/N ratio on morphology, Ga vacancies and electrical transport in (0001) GaN grown by plasma-assisted molecular beam epitaxy at high temperature
- Koblmüller, G.
- Reurings, Floris
- Tuomisto, Filip
- Speck, J.S.
DOIAbstract
The effect of Ga/N flux ratio on surface morphology, incorporation of point defects and electrical transport properties of GaN films grown by plasma-assisted molecular beam epitaxy in a recently developed high-temperature growth regime was investigated. The homoepitaxial (0001) GaN films grown at ∼780–790 °C showed smoothest morphologies near the cross-over between N-rich and Ga-rich growth (0.75<Ga/N<1.1) contrasting previous observations for low-temperature growth. The higher-quality growth near Ga/N∼1 resulted from lower thermal decomposition rates and was corroborated by slightly lower Ga vacancy concentrations [VGa], lower unintentional oxygen incorporation, and improved electron mobilities. The consistently low [VGa], i.e., ∼1016 cm−3...
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