We mainly studied the morphology of GaN structures which were grown by plasma-assisted molecular beam epitaxy. The only condition we changed is Ga/N Ratio. Based on observation of reflection high energy electron diffraction (RHEED) patterns, we found all samples belong to two-dimensional (2D) growth mode. Also, based on scanning electron microscope (SEM) analysis, we found when Ga/N Ratio is 0.13 and 0.18, the surface of sample will be smoothest. Furthermore, based on the roughness result derived from atomic force microscope (AFM), we got the same result.
Then we observed the surface of samples after etching, we found all samples belong to Ga-face. Also, we can detect the degree of the state of mismatch under X-ray diffraction analysis. We found when Ga/N Ratio is 0.13, we got the lowest screw dislocation density; and when Ga/N Ratio is 0.18, we got the lowest overall dislocation density. In conclusion, we are trying to find sample growing parameters which could generate both better morphology and better structure.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0726107-014858 |
| Date | 26 July 2007 |
| Creators | Chang, Yao-i |
| Contributors | Ikai Lo, Ming-Kwei Lee, Jih-Chen Chiang |
| 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-0726107-014858 |
| Rights | withheld, Copyright information available at source archive |
Page generated in 0.002 seconds