Increasing ZnO Growth Rate by Modifying Oxygen Plasma Conditions in Plasma-Assisted Molecular Beam Epitaxy
- 1 Department of Electrical Engineering, The City College of New York, New York, USA
- 2 Department of Electrical Engineering, The City College of New York, New York, USA
Abstract
The authors report that the growth rate of ZnO can be significantly increased by modifying the oxygen plasma conditions in plasma-assisted molecular beam epitaxy. Both the aperture diameter and the distance between the plasma source and the substrate affect the growth rate and the quality of the ZnO films. A short source to substrate distance is essential in achieving higher growth rate, which is explained by reduced chance of oxygen atom collisions to accommodate the short oxygen mean free path at high background pressure. At a shorter source to substrate distance, the growth rate is higher with a larger aperture diameter. The quality of the ZnO thin films grown under different conditions is assessed by x-ray diffraction and room-temperature photoluminescence measurements.
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