There has been much interest in developing scandium doped aluminum nitride (ScAlN) thin films for use in electronic devices, due to their excellent piezoMEMS response, large spontaneous polarization, and the capability for CMOS-compatible integration. As with the undoped AlN film, the formation of an oxide overlayer on the air-exposed ScAlN film can modulate its surface structure and the electrical properties. In this study, we investigate the effects of surface oxidation on a ScAlN film by characterizing the film microstructure and the elemental chemical states. We found that amorphous phase and small crystallites co-exist in the oxide overlayer, which is remarkably different from the columnar (0002) crystalline texture in the bulk ScAlN film. X-ray photoelectron spectroscopy core-level analyses confirm the formation of Al–O and Sc–O bonds. Moreover, the valence band maximum of the oxide overlayer shifts toward a higher binding energy, indicating a high energy barrier at the ScAlN/metal interface. Our results suggest that ScAlN surface oxidation is a chemical reaction-driven and self-limited process.
Skip Nav Destination
Article navigation
12 September 2022
Research Article|
September 15 2022
Oxide overlayer formation on sputtered ScAlN film exposed to air
Special Collection:
Piezoelectric Thin Films for MEMS
Minghua Li
;
Minghua Li
a)
(Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing)
Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR)
, Singapore 138046, Singapore
a)Author to whom correspondence should be addressed: li_minghua@ime.a-star.edu.sg
Search for other works by this author on:
Huamao Lin
;
Huamao Lin
(Conceptualization, Methodology, Resources, Writing – review & editing)
Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR)
, Singapore 138046, Singapore
Search for other works by this author on:
Kan Hu;
Kan Hu
(Data curation, Methodology, Writing – review & editing)
Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR)
, Singapore 138046, Singapore
Search for other works by this author on:
Yao Zhu
Yao Zhu
(Conceptualization, Funding acquisition, Resources, Supervision, Writing – review & editing)
Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR)
, Singapore 138046, Singapore
Search for other works by this author on:
a)Author to whom correspondence should be addressed: li_minghua@ime.a-star.edu.sg
Note: This paper is part of the APL Special Collection on Piezoelectric Thin Films for MEMS.
Appl. Phys. Lett. 121, 111602 (2022)
Article history
Received:
June 29 2022
Accepted:
August 26 2022
Citation
Minghua Li, Huamao Lin, Kan Hu, Yao Zhu; Oxide overlayer formation on sputtered ScAlN film exposed to air. Appl. Phys. Lett. 12 September 2022; 121 (11): 111602. https://doi.org/10.1063/5.0106717
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Sign in via your Institution
Sign in via your InstitutionPay-Per-View Access
$40.00