Method and apparatus for forming film by ion beam

Abstract

An ion beam apparatus which comprises an enclosure defining a chamber of high vacuum. A crucible for producing vapor of a material, ionizing means, ion accelerating means, and a substrate to be deposited with the vaporized material to thereby form a film thereon are disposed within the chamber. An accelerating voltage is applied across the crucible and the accelerating means such that the crucible is of positive polarity while the accelerating means is of negative polarity. The material contained in the crucible is vaporized by heating. A pressure difference is maintained between the vapor pressure within the crucible and the vacuum chamber. The crucible is provided with a small hole for ejecting the vapor of the material into the vacuum chamber to thereby form atom clouds referred to as clusters under adiabatic expansion and supercooling, a part of the clusters being ionized through irradiation of electrons by the ionizing means and accelerated by the accelerating means so that the ionized and accelerated clusters deposit on the substrate to form a thin film thereon. The apparatus further comprises electrostatic optical system interposed between the cluster ionizing region and the substrate to be deposited with the ionized clusters, wherein the electrostatic optical system serves to focus the ionized clusters onto the element to form the thin film thereon through deposition of the ionized clusters.