Published online by Cambridge University Press: 25 February 2011
Conventional chemical vapor deposition (CVD) has historically utilized high melting temperature substrates. Recently there has been an increased desire to coat temperaturesensitive materials such as aluminum, glass, steel, and even plastic. Thus “cold” CVDprocesses, most using plasma excitation, have been developed. In these processes gas molecules or atoms are excited by dc or ac glow discharge, thereby allowing the possibility of keeping substrates at room temperature.
This paper describes plasma CVD reactors using capacitive coupling of r.f. voltage to an asymmetrical arrangement of electrodes. Using organic or metal-organic process gases and mixtures of them with inorganic gases, deposition takes place on the reactor walls, the anode, and the cathode. In this paper the emphasis is on deposition on negatively selfbiased substrate holders. Physical and chemical properties of plasma-CVD grown layers depend on about six process parameters, the most important of which are cathode voltage, gas pressure, choice of gases, and mixing ratio of gases. Map-like representations show the dependence of coating properties on deposition parameters. Layer materials discussed include amorphous hydrogenated carbon (a-C:H). WCx, SiOx:H, SiCxOy:H. and SnOx:H.