Patent ID: 7875864
Filing Date: 2011-01-25
Classification: G03F

Abstract:
1. An EUV lithography system, comprising: a reticle chamber configured to hold a reticle and to be evacuated to a vacuum level during use of the reticle; and an apparatus for reducing particulate contamination of a surface of the reticle as the reticle is being contained in the reticle chamber evacuated to the vacuum level the apparatus comprising (a) a reticle-shield member having a surface that is proximal to and substantially parallel to the surface of the reticle but separated a first distance from the reticle surface so as to define a first space between the surfaces, the shield member defining an opening configured to transmit a beam of EUV radiation to a selected region of the reticle surface for illuminating the region; (b) a gas nozzle manifold situated and configured to supply a gas into the first space such that a first portion of the supplied gas flows in the first space, the gas being at an appropriate temperature relative to the temperature of the reticle-shield member, the gas flow being at an appropriate pressure and flow rate, and the gas flow being substantially parallel to the reticle surface to produce a thermophoretic force in the first space sufficient for inhibiting particles in the gas from contacting the reticle surface, and a second portion of the supplied gas flows relative to the region and then away from the reticle through the opening; and (c) at least one electrophoresis electrode situated relative to the opening and the region, the electrode being configured to produce an electric field sufficient to attract charged particles, in the second portion of the supplied gas, away from the reticle surface in the region as the second portion flows through the opening.