Patent ID: 7365351
Filing Date: 2008-04-29
Classification: B82Y,G03F,G21K,H05G

Abstract:
1. A system for protecting an EUV light source plasma production chamber optical element surface from debris generated by plasma formation, the system comprising: a shield comprising at least one hollow tube having a tube wall that surrounds a tube lumen, the tube being interposed between the plasma formation site and the optical element and oriented to prevent at least a portion of the debris directed toward the optical element surface from reaching the surface and allowing at least a portion of light generated at the plasma formation site to pass through the lumen and reach the optical element surface; and wherein the hollow tube has a first end and a second end, a lumen diameter, d; and defines a linear tube axis from the first end to the second end and wherein the tube is formed with a midsection between the first end and second end, the midsection being laterally offset from the tube axis by an offset distance, D, with D≧d.