Deposition of Amorphous Carbon Films by Laser Induced CVD

Abstract

ABSTRACTAmorphous carbon (a-C) films were prepared by photodissociation of C2H3Cl or CCl4 gas using a pulsed ArF excimer laser (193nm). An increase in the substrate teiperature decreased the deposition rate. For C2H3Cl4 the maximum deposition rate of 10Å/min was attained at a partial pressure of 0.1 Torr and room temperature. In contrast, for CCl4, the maximum deposition rate of 10Å/Min was obtained at a partial pressure of 3 Torr and room temperature. This difference may be attributed to the different absorption cross sections for the two gases. The structural and mechanical properties were leasured. An Auger analysis showed the chlorine content in the a-C film deposited at room temperature to be 1% for C2H3Cl and 8% for CCl4. The Mohs hardnesses of the a-C filis deposited at room teiperature were 7 and 2 for C2H3Cl and CCl4, respectively. It was concluded that both sp2 and sp3 bonds existed between neighboring C atoms at low temperatures, whereas SP2 bond was predominant at temperatures higher than 300°C.