In this thesis, we grew undoped GaN and Si-doped GaN films on sapphire by metal organic chemical vapor deposition (MOCVD) system. For the purpose to investigate the influences of undoped GaN films, we modulated H2 gas flow rate and nitridation time in the undoped GaN growth conditions. The ramping rate, Si2H6 flow rate and undoped GaN film thickness were varied to study the influences on Si-doped GaN films. When H2 gas flow rate was increased, it led to carbon pollution reduced and improved films quality. Too long or too short nitridation time would change film qulity seriously. In the Si-doped GaN films growth, the films quality become worse when the ramping rate was too quick or too slow. The relationship between the carrier concentration of Si-doped GaN films and Si2H6 flow rate was linear. The electron mobility of Si-doped films will not increase apparently until Si2H6 flow rate up to 7.19nmol/min . Undoped GaN film which was pregrown before Si-doped GaN could improve the crystal quality of Si-doped GaN films, and it will influence the optical properties of Si-doped GaN film, such as PL spectra.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0626101-181134 |
| Date | 26 June 2001 |
| Creators | Liu, Kuo-Chung |
| Contributors | Yeong-Her Wang, Uerng-Yih Ueng, Yan-Kuin Su, Mau-Phon Houng |
| 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-0626101-181134 |
| Rights | not_available, Copyright information available at source archive |
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