engleski

GRAZING INCIDENCE SMALL ANGLE X-RAY SCATTERING INVESTIGATION OF TUNGSTEN-CARBON ALLOYS PRODUCED BY REACTIVE MAGNETRON SPUTTERING

Tungsten-carbon thin films were deposited onto monocrystalline silicon substrates by reactive sputtering in a two-source device. The magnetron discharges operated in argon + benzene gas mixture at 2 Pa total pressure. The film structure is strongly disordered, presumably due to the incorporation of the unbound carbon. The films deposited at room temperature and at low benzene concentration exhibit structure resembling a strongly disordered W2C or WC1-x carbides, while WC1-x microcrystalline structure with nanosized grains formed on substrates held at 400OC and with higher benzene concentration during deposition. The grazing incidence SAXS was applied to investigate the structure of the films. The GISAXS spectra from the samples with lower unbound carbon content (low benzene partial pressure and low substrate temperature) can be successfully interpreted according to distorted wave Born approximation (DWBA). In the case of higher carbon content, grains of amorphous WC are formed, while the carbon is probably concentrated in the grain boundaries region. This results in an additional particle like contribution to the scattering, revealing the sizes of the grains to be in the order of 7-16 nm.

grazing incidence; SAXS; magnetron sputtering

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