Ellipsometric Examination of Growth and Dissolution Rates of Ta2 O 5 Films Formed by Metalorganic Chemical Vapor Deposition
Abstract
The formation process of Ta2O5 films in MOCVD using pentamethoxy tantalum (PMT) as a metal organic source and O2 as reactant gas has been analyzed by in situ ellipsometry at deposition temperatures of 473-773 K. According to the change in the growth rate of the films, the formation process can be divided into three stages, the initial, the transition, and the final stages. The growth rate and the optical constant of the films were found to depend on the deposition temperature and the deposition time. All the films obtained at temperatures of 473-773 K had amorphous structures. The corrosion resistance of the films against a buffered HF solution depended on the deposition temperature. By annealing at 923 K in the air for 3.6 ks, amorphous Ta2O5 films deposited at temperatures higher than 673 K were transformed into polycrystalline structures. Ta2O5 films crystallized by annealing showed extremely high corrosion resistances.
- Publication:
-
Journal of the Electrochemical Society
- Pub Date:
- July 1992
- DOI:
- 10.1149/1.2069529
- Bibcode:
- 1992JElS..139.1956A
- Keywords:
-
- Crystal Growth;
- Ellipsometry;
- Metalorganic Chemical Vapor Deposition;
- Oxide Films;
- Tantalum Oxides;
- Amorphous Materials;
- Corrosion Resistance;
- Refractory Materials;
- Solid-State Physics