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Title:
HIGH-NA PROJECTION OBJECTIVE
Document Type and Number:
Japanese Patent JP2007298984
Kind Code:
A
Abstract:

To provide a catadioptric projection objective with potential for very high image-side NA.

A catadioptric projection objective for imaging a pattern provided in an object surface onto an image surface thereof has an object-side imaging subsystem for creating a final intermediate image closest to the image surface from radiation coming from the object surface and an image-side imaging subsystem for directly imaging the final intermediate image into the image surface. The image-side imaging subsystem includes a last optical element closest to the image surface and is designed for creating a convergent beam having an aperture sinα≥0.8 in the last optical element. The image-side imaging subsystem includes, in this order along a propagation direction of radiation: a primary negative lens group having overall negative refractive power; an intermediate positive lens group having overall positive refractive power; a secondary negative lens group having overall negative refractive power; and a final positive lens group having overall positive refractive power and including the last optical element, where the last optical element has a convex entry surface having a radius RLOEof curvature with RLOE/NA<40 mm.

COPYRIGHT: (C)2008,JPO&INPIT


Inventors:
DODOC AURELIAN
Application Number:
JP2007113140A
Publication Date:
November 15, 2007
Filing Date:
April 23, 2007
Export Citation:
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Assignee:
ZEISS CARL SMT AG
International Classes:
G02B17/08; G02B13/18; H01L21/027
Foreign References:
WO2005059617A22005-06-30
Attorney, Agent or Firm:
Toru Tanabe