Patent ID: 8018572
Filing Date: 2011-09-13
Classification: G03F

Abstract:
1. A lithographic apparatus comprising: a radiation system configured to form a projection beam of radiation, comprising: (a) a radiation source that emits radiation; (b) a filter system for filtering debris particles out of the radiation emitted by the radiation source, the filter system including a plurality of foils for trapping the debris particles, at least one foil of the plurality of foils including a first part and a second part that have mutually different orientations and that are connected to each other along a substantially straight connection line, the first part substantially coinciding with a first virtual plane that extends through a predetermined position that substantially coincides with the radiation source, the second part substantially coinciding with a second virtual plane that extends through the predetermined position that substantially coincides with the radiation source, and the substantially straight connection line coinciding with a virtual straight line that also extends through the predetermined position; and (c) an illumination system configured to form the radiation emitted by the radiation source into a conditioned radiation beam; and a projection system configured to project the projection beam of radiation onto a substrate.