DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click
HERE to register or log in.
Accession Number:
AD1099399
Title:
Impact of Growth Conditions on the Phase Selectivity and Epitaxial Quality of TiO2 Films Grown by the Plasma-Assisted Atomic Layer Deposition
Corporate Author:
NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States
Report Date:
2019-05-15
Abstract:
Plasma-enhanced atomic layer deposition PE-ALD is a promising method to grow conformal, epitaxial films at low temperatures 300 degrees C. In this study, PE-ALD was used to deposit high-quality, epitaxial anatase and rutile TiO2 thin films on sapphire substrates with various orientations c-, m-, and a-Al2O3. For all substrate orientations, the influence of ALD growth temperature and plasma gas chemistry on the film morphology, phase, and crystallinity was investigated. On c-Al2O3, using a mixed Ar-O-2 plasma, the phase selectivity between anatase and rutile TiO2 could be achieved by simply controlling the growth temperature from 150 to 350 degrees C. By using a pure O-2 plasma, single-phase rutile TiO2 was grown independent of temperature or substrate orientation. Additionally, using a pure O-2 plasma resulted in higher crystalline quality films as growth temperatures were reduced, resulting in single-phase crystalline films at 150 degrees C. Although high-quality rutile films were attained on c- and m-Al2O3, only low-quality crystalline rutile films were produced on a-Al2O3. These results demonstrate the benefits of a PE-ALD approach toward depositing epitaxial TiO2 under low-temperature conditions that is of high quality, phase and strain selective.
Descriptive Note:
Journal Article - Open Access
Supplementary Note:
Chemistry of Materials , 31, 11, 01 Jan 0001, 01 Jan 0001,
Pages:
0009
Distribution Statement:
Approved For Public Release;
File Size:
4.82MB
