Effect of high temperature deposition on CoSi{sub 2} phase formation

Journal Article · Fri Jun 21 00:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4811352· OSTI ID:22163061

Comrie, C. M. ^[1]; Ahmed, H. ^[1]; Smeets, D.; Demeulemeester, J.; Vantomme, A. ^[2]; Turner, S.; Van Tendeloo, G. ^[3]; Detavernier, C. ^[4]

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1. Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa)
2. Instituut voor Kern- en Stralingsfysica, KU Leuven, B-3001 Leuven (Belgium)
3. EMAT, Universiteit Antwerpen, B-2020 Antwerpen (Belgium)
4. Vakgroep Vaste-Stofwetenschappen, Universiteit Gent, B-9000 Gent (Belgium)

This paper discusses the nucleation behaviour of the CoSi to CoSi{sub 2} transformation from cobalt silicide thin films grown by deposition at elevated substrate temperatures ranging from 375 Degree-Sign C to 600 Degree-Sign C. A combination of channelling, real-time Rutherford backscattering spectrometry, real-time x-ray diffraction, and transmission electron microscopy was used to investigate the effect of the deposition temperature on the subsequent formation temperature of CoSi{sub 2}, its growth behaviour, and the epitaxial quality of the CoSi{sub 2} thus formed. The temperature at which deposition took place was observed to exert a significant and systematic influence on both the formation temperature of CoSi{sub 2} and its growth mechanism. CoSi films grown at the lowest temperatures were found to increase the CoSi{sub 2} nucleation temperature above that of CoSi{sub 2} grown by conventional solid phase reaction, whereas the higher deposition temperatures reduced the nucleation temperature significantly. In addition, a systematic change in growth mechanism of the subsequent CoSi{sub 2} growth occurs as a function of deposition temperature. First, the CoSi{sub 2} growth rate from films grown at the lower reactive deposition temperatures is substantially lower than that grown at higher reactive deposition temperatures, even though the onset of growth occurs at a higher temperature, Second, for deposition temperatures below 450 Degree-Sign C, the growth appears columnar, indicating nucleation controlled growth. Elevated deposition temperatures, on the other hand, render the CoSi{sub 2} formation process layer-by-layer which indicates enhanced nucleation of the CoSi{sub 2} and diffusion controlled growth. Our results further indicate that this observed trend is most likely related to stress and changes in microstructure introduced during reactive deposition of the CoSi film. The deposition temperature therefore provides a handle to tune the CoSi{sub 2} growth mechanism.

• OSTI ID: 22163061
• Journal Information: Journal of Applied Physics, Vol. 113, Issue 23; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COBALT SILICIDES
CRYSTAL GROWTH
CRYSTAL STRUCTURE
DEPOSITION
DIFFUSION
EPITAXY
LAYERS
MICROSTRUCTURE
RUTHERFORD BACKSCATTERING SPECTROSCOPY
SOLIDS
SUBSTRATES
TEMPERATURE RANGE 0400-1000 K
THIN FILMS
TRANSFORMATIONS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION