This study presents the GaSb epitaxial grown by molecular beam epitaxy (MBE) on the semi-insulating GaAs substrate and n+-GaAs substrate. Investigations are made to the effect of Sb4/Ga beam equivalent pressure (BEP) ratios on the current-voltage characteristics of the p-n hetero-junction and the metal-GaSb semiconductor Schottky contact for various metals deposited on n-type GaSb layers. Several growth conditions were taken to improve the quality of GaSb epitaxial films. The structure of GaSb epitaxial layers are characterized by the X-ray diffraction, and the optimum growth conditions 500¢J of substrate temperature and the Sb4/Ga flux ratio about 2~3 have been obtained.
From the I-V curve of GaSb Schottky diodes, we know that the higher Sb4/Ga ratio will induce the lower breakdown voltage. Hence, the interface properties of hetero-junction between the GaSb/GaAs and metal/GaSb can be investigated by the current-voltage characteristics, in which the current leakages and the surface state density are strongly dependent on the ratio of Sb4/Ga BEP.
Based on the thermionic emission theory, the barrier height obtained was decrease with the Sb4/Ga ratio increases. After metal deposited on the GaSb epitaxial film to form the Schottky diode, the density of surface states can be calculated from the relationship of metal work-function and barrier height, which were obtained from the current-voltage characteristics of Schottky diode measurement, and then it also found that the density of surface states show decrease as the Sb4/Ga ratio increase.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0719106-210520 |
| Date | 19 July 2006 |
| Creators | Hung, Chih-Wen |
| Contributors | Wang-Chuang Kuo, Wei-Chou Hsu, Herng-Yih Ueng, Chih-Hsiung Liao |
| 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-0719106-210520 |
| Rights | not_available, Copyright information available at source archive |
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