US 7,352,434 B2
Lithographic apparatus and device manufacturing method
Bob Streefkerk, Tilburg (Netherlands); Levinus Pieter Bakker, Helmond (Netherlands); Johannes Jacobus Matheus Baselmans, Oirschot (Netherlands); Henrikus Herman Marie Cox, Eindhoven (Netherlands); Antonius Theodorus Anna Maria Derksen, Eindhoven (Netherlands); Sjoerd Nicolaas Lambertus Donders, 's-Hertogenbosch (Netherlands); Christiaan Alexander Hoogendam, Veldhoven (Netherlands); Joeri Lof, Eindhoven (Netherlands); Erik Roelof Loopstra, Heeze (Netherlands); Jeroen Johannes Sophia Maria Mertens, Duizel (Netherlands); Frits Van Der Meulen, Breda (Netherlands); Johannes Catharinus Hubertus Mulkens, Waalre (Netherlands); Gerardus Petrus Matthijs Van Nunen, Berghem (Netherlands); Klaus Simon, Eindhoven (Netherlands); Bernardus Antonius Slaghekke, Veldhoven (Netherlands); Alexander Straaijer, Eindhoven (Netherlands); Jan-Gerard Cornelis Van Der Toorn, Eindhoven (Netherlands); and Martijn Houkes, Sittard (Netherlands)
Assigned to ASML Netherlands B.V., Veldhoven (Netherlands)
Filed on May 13, 2004, as Appl. No. 10/844,575.
Claims priority of application No. 03252955 (EP), filed on May 13, 2003; and application No. 03256643 (EP), filed on Oct. 22, 2003.
Prior Publication US 2005/0007569 A1, Jan. 13, 2005
Int. Cl. G03B 27/42 (2006.01); G03B 27/52 (2006.01)
U.S. Cl. 355—53  [355/30] 43 Claims
OG exemplary drawing
 
1. A lithographic projection apparatus, comprising:
a substrate table configured to hold a substrate;
a projection system configured to project a patterned beam of radiation onto a target portion of the substrate and having an optical axis;
a liquid supply system configured to provide an immersion liquid on less than an entire surface of the substrate in a space between the projection system and the substrate, wherein at least part of the liquid supply system is free to move in the direction of the optical axis and/or rotate about at least one axis perpendicular to the optical axis;
a measurement system configured to determine a height of at least part of the liquid supply system above the surface of the substrate or configured to determine a surface height of the substrate; and
a control system configured to control the height of at least part of the liquid supply system above the surface of the substrate using the determined height.