Abstract: A low energy (10 to 300 eV), mass-selected ion beam is used to deposit thin films on atomically clean substrate surfaces. For example, a C.sup.+ ion beam may be used to deposit a chemically bonded diamond or diamondlike film on a substrate at room temperature. For thin carbon films, the initial monolayer of the deposited film is in the form of a carbide layer which is chemically bonded to the substrate atoms. The film evolves gradually over the next several layers deposited, through intermediate structures, into a diamond structure. The optimum C.sup.+ energy range for formation of the diamond structure is about 30 to 175 eV. Below 10 eV the final diamond structure has not been attained and above 180 eV there is a sharp increase in the dose required to attain this final structure. Multiple ion beams may be used to deposit multicomponent films including films doped with very low concentrations of foreign atoms. The diamond films produced by this process are found to be free of impurities, inert to O.sub.

Abstract: This invention comprises a method by which a carbon based film is deposited by ion beam deposition upon and chemically bonded to a substrate article. The carbon based film deposited by the method of this invention comprises an atomic initial layer, adjacent to and chemically bonded by carbide bonding to the substrate surface, which is overgrown by a carbon layer that assumes the true diamond microstructure or, alternatively, a carbon structure which more closely approximates the microstructure and physical, chemical and electrical properties of true diamond than has heretofore been attained by prior diamond-like films.The method by which the chemically bonded diamond or diamond-like film is deposited upon a substrate comprises: positioning an electrically grounded substrate having an atomically clean surface within a deposition chamber maintained at a pressure of 1.times.10.sup.-9 torr or less and impinging upon the atomically clean substrate surface a .sup.12 C.sup.