NEW TECHNOLOGY FOR PACVD

Plasma-assisted chemical vapour deposition (PACVD) has many advantages for the deposition of thin films. The use of ions for the energetic b ombardment of the film during growth is an important technique for pro ducing dense-structures, This paper discusses recent progress in the u nderstanding of the effects of energetic bombardment on the stress lev els and structure of films produced by plasma deposition processes. Di agnostic equipment, such as the in situ ellipsometer, energy selecting mass spectrometer and residual gas analyser, enables the PACVD proces s to be closely monitored so that conditions at the growth surface can be accurately controlled. New plasma sources, such as the helicon pla sma source, give increased ion fluxes. The cathodic are source is also an intense Source or highly ionized plasma which can be used for PACV D. The deposition of rugate optical structures based on SiOxNy can be carried out using a PACVD;process in which the refractive index profil e is created by the computer central of gas flows. The helicon plasma source is useful for the deposition of SiO2 films and has been adapted for use in an ion plating process for the deposition of cubic phase B N. The deposition of amorphous hydrogenated carbon films by PACVD of a cetylene in a cathodic are has been shown to be possible and demonstra tes the effect of using a highly ionized plasma for PACVD.