Patent ID: 6814838
Filing Date: 2004-11-09
Classification: H01J

Abstract:
A vacuum treatment chamber for workpieces comprising a treatment space in which the workpieces are treated, at least one induction coil encircling said treatment space and having a coil axis at least for contributing to generation of a plasma within said treatment space for excitation of a plasma thereat, a self-contained hollow screen body having an inner surface and an outer surface configured as a substantially thin-walled cylindrical member so as to be replaceable as a unit, said hollow screen body being arranged substantially coaxially to said coil axis within said treatment space, the inner surface of said hollow screen body being freely exposed to said treatment space, said hollow screen body having a pattern of through-slots extending substantially in a direction of said coil axis and being distributed around said coil axis to allow for direct line-of-sight paths along the through-slots from the outer surface to the inner surface of said hollow screen body, with a density S of said slots of said pattern per cm taken in a circumferential direction of said screen body being at least 0.5.