Both non-polar (10-10) (m-plane) and polar (0001) (c-plane) zinc oxide (ZnO) have a good lattice match with lithium aluminum (LiAlO2, LAO) (200) substrate, so it is difficult to control the epitaxial orientation. Therefore, this research is to explore how the growth parameters influence on the crystal orientation of ZnO film grown by plasma assisted molecular beam epitaxy.
The experimental results show that m-plane ZnO can be grown with low zinc flux and low oxygen pressure. Increasing zinc flux and oxygen pressure will lead to increase in growth rate, and consequently, c-plane ZnO will nucleate on the substrate besides m-plane zinc oxide. The substrate temperature is one of the main factors that influence the choice of zinc oxide epitaxial orientation. High temperature will promote the m-plane zinc oxide nucleation, while low temperature will conduct to the c-plane zinc oxide nucleation. Under low zinc flux and low oxygen pressure, epitaxy of ZnO with different crystalline orientations can be achieved through changing the substrate temperature.
The surface morphology and roughness of the substrate will affect the particle size and surface morphology of ZnO epilayers. When the substrate is smooth, the crystal size of the epitaxial film is large and the surface is flat with many rectangular stripes, taking on the platform-like morphology. If the substrate is rough with many scratches, the particle size becomes small and the surface is granular-like and rather rough. Furthermore, when the substrate is rough, it is difficult to control the different orientations of ZnO epitaxial films through changing the substrate temperature.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0820112-204958 |
| Date | 20 August 2012 |
| Creators | Chen, Yen-ming |
| Contributors | Der-shin Gan, Liuwen Chang, Jih-Jen Wu, Ming-Chi Chou |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0820112-204958 |
| Rights | user_define, Copyright information available at source archive |
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