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US006906790B2
(12) United States Patent ao) Patent No.: us 6,906,790 B2
Kikuchi et al. (45) Date of Patent: Jun. 14,2005
(54) RETICLE MANIPULATORS AND RELATED METHODS FOR CONVEYING THIN, CIRCULAR RETICLES AS USED IN CHARGED-PARTICLE-BEAM MICROLITHOGRAPHY
(75) Inventors: Hidekazu Kikuchi, Miyagi Prefecture (JP); Akihiro Yamamoto, Sendai (JP)
(73) Assignee: Nikon Corporation, Tokyo (JP)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 10/635,661
(22) Filed: Aug. 5, 2003
(65) Prior Publication Data
US 2004/0027552 Al Feb. 12, 2004 (30) Foreign Application Priority Data
Aug. 5, 2002 (JP) 2002-226927
(51) Int. CI.7 G03B 27/42
(52) U.S. CI 355/75; 355/53; 355/72;
414/935; 414/936; 414/940; 414/941; 396/611
(58) Field of Search 355/53, 72, 77;
414/935-941; 396/611
(56) References Cited
U.S. PATENT DOCUMENTS
5,937,223 A * 8/1999 Akimoto et al 396/604
Robotic reticle manipulators are disclosed for use in holding and conveying, with good stability, thin, circular reticles as used in charged-particle-beam micro lithography. A manipulator embodiment includes at least one arm configured for executing movements in the X-, Y-, and Z-directions. Connected distally to the at least one arm is a U-shaped fork (as an exemplary reticle-support member) defining recessed surfaces and vacuum ports for holding the reticle at the reticle's narrow handling zone located along the periphery of the reticle. Each vacuum port includes an upwardly extending lip that defines, on its "upward"-facing surface, a respective reticle-contact surface. Three such vacuum ports are provided on the fork and are nearly equidistantly separated from one another. Thus, as the reticle is being held and conveyed by the manipulator, the reticle is securely held to prevent reticle damage.
38 Claims, 4 Drawing Sheets
