Plasma Chemical Synthesis of Amorphous Hydrocarbon Films Alloyed by Silicon, Oxygen and Nitrogen

The paper presents the synthesis of amorphous hydrocarbon (a-C:H) films alloyed by silicon, oxygen and nitrogen. The films obtained in polyphenyl methylsiloxane vapor and argon/nitrogen environment are deposited onto crystalline silicon surface using plasma chemical deposition. It is shown that the physical and mechanical properties of the films depend on the nitrogen concentration. The film composition is studied by Xray fluorescence spectrometry and Fourier-transform infrared spectroscopy. Raman spectroscopy is used to explore the film structure. A nanoindenter is used for testing the indentation hardness and other mechanical parameters of the films. It is shown that the chemical composition and properties of a-C:H:SiO_x:N film can be maintained by changing the partial nitrogen pressure during the film deposition. The increase in the nitrogen content in a-C:H:SiO_x:N film leads to the growth in the root mean square roughness and the contact angle. It also leads to the reduction in the carbon content and the film hardness caused by the lower content of sp³ carbon phase.