Method and apparatus for forming film by ion beam

Claim 1

An ion beam apparatus comprising an enclosure defining a chamber of high vacuum, said chamber accommodating therein a furnace for producing vapor of a material contained therein, ionizing means, ion accelerating means, and an element to be deposited with said vaporized material to thereby form a film thereon, wherein an accelerating voltage is supplied across said furnace and said accelerating means such that said furnace is of positive polarity while said accelerating means is of negative polarity, said material contained in said vapor generating furnace being vaporized under heating, a pressure difference being maintained between vapor pressure within said furnace and said vacuum chamber, said furnace being provided with an opening for ejecting the vapor of said material into said vacuum chamber to thereby form atom clouds referred to as clusters under adiabatic expansion and supercooling, a part of said clusters being ionized through irradiation of an electron beam by said ionizing means and accelerated by said accelerating means so that said ionized and accelerated clusters deposit on said element to form a thin film, an electrostatic optical system interposed between the cluster ionizing region and said element to be deposited with said ionized clusters, and means for preventing contamination of the thin film formed on said element including a partition plate disposed between said element to be deposited with the ionized clusters and at least a part of said electrostatic optical system, said partition plate having an opening formed therein, wherein said electrostatic optical system serves to change a path to be followed by said ionized clusters to focus said ionized clusters at said opening of said partition plate so as to only enable said focused ionized clusters to pass through said partition plate to form an uncontaminated thin film on said element through deposition of said ionized clusters, and vapor deposition enhancing/improving means being provided in association with a deposition chamber defined by said partition plate in which said element is disposed, said vapor deposition enhancing/improving means including evacuating means connected to said deposition chamber for producing a vacuum in said deposition chamber.