TITLE:
Densification of Thin Aluminum Oxide Films by Thermal Treatments
AUTHORS:
V. Cimalla, M. Baeumler, L. Kirste, M. Prescher, B. Christian, T. Passow, F. Benkhelifa, F. Bernhardt, G. Eichapfel, M. Himmerlich, S. Krischok, J. Pezoldt
KEYWORDS:
Atomic Layer Deposition, Crystallization, Thermal Treatment, Aluminum Oxide
JOURNAL NAME:
Materials Sciences and Applications,
Vol.5 No.8,
June
30,
2014
ABSTRACT:
Thin AlOx films were grown on 4H-SiC by plasma-assisted atomic
layer deposition (ALD) and plasma assisted electron-beam evaporation at 300°C. After
deposition, the films were annealed in nitrogen at temperatures between 500°C and
1050°C. The films were analyzed by X-ray reflectivity (XRR) and atomic force microscopy
(AFM) in order to determine film thickness, surface roughness and density of the
AlOx layer. No differences were found in the behavior of AlOx films upon annealing for the two different employed deposition techniques. Annealing
results in film densification, which is most prominent above the crystallization
temperature (800°C). In addition to the increasing density, a mass loss of ~5% was
determined and attributed to the presence of aluminum oxyhydroxide in as deposited
films. All changes in film properties after high temperature annealing appear to
be independent of the deposition technique.