Influence of growth temperature on dielectric strength of Al2O3 thin films prepared via atomic layer deposition at low temperature

• Published in: Scientific reports Vol. 12; no. 1; p. 5124
• Main Authors: Kim, Suyeon, Lee, Seung-Hun, Jo, In Ho, Seo, Jongsu, Yoo, Yeong-Eun, Kim, Jeong Hwan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24-03-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301; 639/925; Aluminum oxide; Electronic equipment; Growth rate; Humanities and Social Sciences; Impurities; Low temperature; multidisciplinary; Oxidation; Photoelectron spectroscopy; Science; Science (multidisciplinary); Temperature; Thin films
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-09054-7

Thin films grown via atomic layer deposition (ALD) suffer from insufficient growth rate and unreliability for temperature-sensitive electronic substrates. This study aimed to examine the growth characteristics and dielectric strength of ALD Al
2
O
3
films grown at low temperatures (≤ 150 °C) for potential application in flexible electronic devices. The growth rate of the Al
2
O
3
films increased from 0.9 to 1.1 Å/cycle with increasing temperature and saturated at growth temperatures ≥ 150 °C, which is the critical temperature at which a complete oxidation reaction occurred. The dielectric strength was also improved with increasing growth temperature, and the films grown at 150 °C showed a high breakdown field strength (~ 8.3 MV/cm), attributable to the decrease in the carbon impurities and oxygen defects, as confirmed by X-ray photoelectron spectroscopy. Even at low growth temperatures (≤ 150 °C), ALD Al
2
O
3
films showed an overall amorphous structure and extremely smooth surfaces regardless of the growth temperature.