CONTAMINATION BARRIER WITH EXPANDABLE LAMELLA FOR COATING DEBRIS FROM RADIATION SOURCE

摘要

PURPOSE: Provided is a contamination barrier containing expandable lamella to catch debris generated from radiation source and to minimize abnormal modification of the source by irradiation of radiant rays. CONSTITUTION: The contamination barrier comprises numbers of lamella radially extending from a main axial line each of which is set up on planar side including the main axial line; and inner and outer rings. Each of the lamella is located in at least one outer ends of one or more grooves among the inner and the outer rings possible in slidable manner. Such barrier is generally mounted in a wall between two vacuum chambers in radiation system of conventional lithographic projection apparatus. As one of the contamination barrier, a foil trap comprising thermal shield(41) and two cooling spokes(44,45) mechanically and thermally jointed to outer ring(35) to support the thermal shield(41) is provided. The thermal shield(41) is connected to a spindle(47) and prevents inner ring from being damaged by radiation or heat from the radiation source.