Due to the high electron mobility compared with Si, III-V compound semiconductors (GaAs) has been applied widely for high-speed devices. The titanium oxide (TiO2) has not only has high dielectric constant but has well lattice match with GaAs substrate. Therefore, the high-k material TiO2 was chosen to be the gate oxide in this study.
The major problem of III-V compound semiconductors is known to have poor native oxide on it and leading to the Fermi level pinning at the interface between oxide and semiconductor. The C-V stretch-out phenomenon can be observed and the leakage current is high. The surface passivation of GaAs with (NH4)2Sx treatment (S-GaAs) can prevent it from oxidizing after cleaning and improve the interface properties.
In order to passivate the grain boundary of polycrystalline ALD-TiO2 film and the interface state, the fluorine from liquid-phase- deposited SiO2 solution can achieve the goal effectively.
In addition, the post-metallization annealing (PMA) is another efficiency way to improve the ALD-TiO2 film quality. The mechanism of PMA process is the reaction between the aluminum contact and hydroxyl groups existed on TiO2 film surface. Then the active hydrogen is produced to diffuse through the oxide and passivate the oxide traps.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0804109-122205 |
| Date | 04 August 2009 |
| Creators | Chen, Da-Ching |
| Contributors | none, none, none, Ming-Kwei Lee, none, none, none, none |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0804109-122205 |
| Rights | withheld, Copyright information available at source archive |
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