Mechanická napětí v DL uhlíkových vrstvách obsahujících Si a O studovaná optickými metodami

Mechanical stresses studied by optical methods in diamond-like carbon films containing Si and O

conference paper

en

The quantitative dependence of the mechanical stress inside diamond-like carbon films containing Si and O atoms on a flow rate ratio of methane and hexamethyldisiloxane in the deposition mixture is determined. The modified Stoneys formula is employed for this purpose. The important quantities taking place in this folmula, i.e. the radius of curvature of the spherical surface of a deformed silicon substrate and the film thickness, are determined using the combined optical method based on two-beam interferometry, variable angle spectroscopic ellipsometry and near-normal spectroscopic reflectometry. It is shown that the influence of the flow rate ratio on the values of the mechanical stresses taking place inside these films is negligible within the experimental accuracy achieved for determining these stresses if the total flow rate of gases used to be constant in the deposition mixture. The films studied were prepared using the plasma enhanced chemical vapor deposition.

Je určena kvantitativní závislost mechanického napětí v DL uhlíkových vrstvách obsahujících atomy Si a O na podílu metanu a hexametyldisiloxanu v deponované směsi. Pro tento účel byla použita modifikovaná Stoneyova formule. Významné veličiny vystupující v této formuli, tj. poloměr křivosti deformovaného křemíkového substrátu a tloušťka vrstvy, jsou určeny pomocí kombinované optické metody založené na využití dvoupaprskové interferometrie, spektrální elipsometrie s proměnným úhlem dopadu a spektroskopické reflektomerie při téměř kolmém dopadu. Je ukázáno, že vliv podílu plynných složek v deponované směsi je v rámci experimentální přesnosti dosažené při určování mechanického napětí zanedbatelný, pokud je udržován konstantní tok těchto plynů. Studované vrstvy byly připraveny metodou PECVD.

The quantitative dependence of the mechanical stress inside diamond-like carbon films containing Si and O atoms on a flow rate ratio of methane and hexamethyldisiloxane in the deposition mixture is determined. The modified Stoneys formula is employed for this purpose. The important quantities taking place in this folmula, i.e. the radius of curvature of the spherical surface of a deformed silicon substrate and the film thickness, are determined using the combined optical method based on two-beam interferometry, variable angle spectroscopic ellipsometry and near-normal spectroscopic reflectometry. It is shown that the influence of the flow rate ratio on the values of the mechanical stresses taking place inside these films is negligible within the experimental accuracy achieved for determining these stresses if the total flow rate of gases used to be constant in the deposition mixture. The films studied were prepared using the plasma enhanced chemical vapor deposition.

DLC vrstvy, mechanické napětí, dvoupaprsková interferometrie

DLC films, mechanical stress, two-beam interferometry

2004

01.08.2004

SPIE-The International Society for Optical Engineering

Bellingham, Washington, USA

0-8194-5465-6

Advances in Thin Film Coatings for Optical Applications

5527

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