Patent ID: 6248219
Filing Date: 2001-06-19
Classification: C23C,H01J

Abstract:
A process for sputtering a surface of an object, comprising the steps of:(a) providing in a vacuum recipient a first and second conductive electrode with a first and a second electrode surface respectively;(b) selecting a gas pressure for working gas to be applied to said vacuum recipient;(c) confining a discharge space in said recipient defined by said first and second electrode surfaces, thereby preventing an RF discharge generated between said first and second electrode surfaces to spread outside the confined discharge space;(d) generating an RF plasma discharge in said discharge space with said working gas at a gas pressure selected during step (b) by applying an electric RF field between said first and second electrode surfaces, thereby generating in said space and adjacent said first electrode surface a first dark space region with a first drop of time-averaged electric potential and adjacent said second electrode surface a second dark space region with a second drop of time-averaged electric potential, said first and second drops of time-averaged electric potential falling towards said first and second electrode surfaces respectively;(e) selecting a ratio R.sub.A12 of areas of said first to second electrode surfaces to be 0.3.ltoreq.R.sub.A12 <1;(f) disposing said surface of said object in said second dark space region adjacent said second electrode surface, said second electrode surface being larger than said first electrode surface and said surface of said object facing said first dark space region thereby disposing said surface of said object at one of a floating electric potential and at an electric potential of said second electrode surface, so as to perform diode sputtering; and(g) applying a magnetic field within said discharge space to said first electrode to enable sputtering of said surface of said object adjacent said second and large electrode surface, a predominant part of lines of force of the magnetic field having being tunnel shaped on said first electrode surface and across said first dark space region.