Method of depositing diamond-like carbon film onto a substrate having a low melting temperature

摘要

A diamond-like carbon film is deposited on an insulating substrate using a solid carbon source evaporated by an electron beam so as to maintain the substrate temperature below about 150 C. in a differentially evacuated chamber containing a selective etchant gas such as hydrogen. In orer to bombard the substrate with positively charged ions while preventing accumulation of a repulsive surface charge, a radio frequency (RF) electric field is applied to a rotating fixture holding the substrate. The differentially evacuated chamber maintains the atmospheric pressure around the solid carbon source at one end of the chamber at a sufficiently low pressure to prevent loss of electron beam energy and thereby enable vaporization of the carbon while maintaining the substrate at the other end of the chamber at a higher pressure which enables the RF electric field to excite an ion gas plasma around the substrate and thereby facilitate deposition of the diamond-like carbon film. In the preferred embodiment, the differentially evacuated chamber has a bypass manifold connected between the two ends of the chamber. A control system responding to pressure sensing apparatus inside the chamber governs the position of a butterfly valve in the bypass manifold to regulate the differential pressure in the chamber. In order to keep the substrate temperature below about 150, the rotating fixture holding the substrate is water-cooled.