06954256 is referenced by 183 patents and cites 45 patents.

In a lithographic projection apparatus, a space between an optical element is filled with a first fluid and a second fluid separated by a transparent plate. The first and second fluids have first and second indices of refraction, respectively, that are different from one another. The first fluid is provided between a substrate and the transparent plate and has an index of refraction similar to the index of refraction of the substrate. The second fluid is provided between the transparent plate and the optical element and has an index of refraction similar to the index of refraction of the optical element. The transparent plate has a third index of refraction between the first and second indices of refraction and may be equal to the first index of refraction or the second index of refraction. A device manufacturing method includes filling a space between the optical element and the substrate with at least two fluids having different indices of refraction.

Title
Gradient immersion lithography
Application Number
10/698012
Publication Number
6954256 (B2)
Application Date
October 31, 2003
Publication Date
October 11, 2005
Inventor
John Doering
Tempe
AZ, US
Donis Flagello
Scottsdale
AZ, US
Agent
Pillsbury Winthrop Shaw Pittman
Assignee
ASML Netherlands
NL
IPC
G03B 027/52
G03B 027/42
G03B 027/32
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