Erik R Loopstra, Gerrit M Bonnema, Harmen K Van Der Schoot, Gerjan P Veldhuis, Yim Bun P Kwan: Positioning device having two object holders. ASM Lithography, Pillsbury Winthrop, July 17, 2001: US06262796 (335 worldwide citation)

A positioning device has first and second object holders that are guided over a guiding surface extending parallel to an X-direction and parallel to a Y-direction perpendicular to the X-direction and which are displaceable over the guiding surface from a first position into a second position by mean ...

Erik R Loopstra, Alexander Straaijer: Interferometer system and lithograph apparatus including an interferometer system. ASM Lithography, IP Group of Pillsbury Madison & Sutro, February 1, 2000: US06020964 (144 worldwide citation)

A composite interferometer system has a plurality of X and/or Y measuring axes which co-operate with an X and/or Y measuring mirror arranged on an object. The interferometer system also has at least one Z measuring axis, which extends partly in an XY plane and co-operates with Z measuring mirrors ar ...

Johannes C M Jasper, Erik R Loopstra, Theodorus M Modderman, Gerrit J Nijmeijer, Nicolaas A A J van Asten, Frederik T E Heuts, Jacobus Gemen, Richard J H Du Croo de Jongh, Marcus E J Boonman, Jacob F F Klinkhamer, Thomas J M Castenmiller: Off-axis levelling in lithographic projection apparatus. ASML Netherlands, Pillsbury Winthrop, January 6, 2004: US06674510 (94 worldwide citation)

In an off-axis levelling procedure a height map of the substrate is generated at a measurement station. The height map is referenced to a physical reference surface of the substrate table. The physical reference surface may be a surface in which is inset a transmission image sensor. At the exposure ...

Santiago del Puerto, Erik R Loopstra, Andrew Massar, Duane P Kish, Abdullah Alikhan, Woodrow J Olson, Jonathan H Feroce: System for using a two part cover for protecting a reticle. ASML Holding, Sterne Kessler Goldstein & Fox P L L C, June 14, 2005: US06906783 (37 worldwide citation)

A system and method are used to protect a mask from being contaminated by airborne particles. They include providing a reticle secured in a two-part cover. The two part cover includes a removable protection device used to protect the reticle from contaminants. The cover can be held inside a pod or b ...

Raymond L J Schrijver, Tjarko A R van Empel, Marcel K M Baggen, Bernardus A J Luttikhuis, Yim Bun P Kwan, Erik R Loopstra: Purge gas systems for use in lithographic projection apparatus. ASML Netherlands, Pillsbury Winthrop, April 1, 2003: US06542220 (33 worldwide citation)

A lithographic apparatus has at least one compartment closely surrounding at least one of the mask and substrate holders but not either of the illumination or projection systems so as to reduce the volume that must be purged with gas transparent to the projection radiation. In a scanner, the compart ...

Frank B Sperling, Erik R Loopstra, Antonius T A Peijnenburg: Positioning device having three coil systems mutually enclosing angles of 120.degree. and lithographic device comprising such a positioning device. ASM Lithography, Pillsbury Madison & Sutro, April 25, 2000: US06054784 (20 worldwide citation)

A positioning device is disclosed. The positioning device has a first part and a second part, the second part further has an object table. The second part may be displaced relative to the first part parallel to the XY-plane and may be rotated about the Z-axis by means of three motors. The motors are ...

Erik R Loopstra, Frank B Sperling, Hendricus J M Meijer, Jan Van Eijk: Lithographic device with a three-dimensionally positionable mask holder. U S Philips Corporation, June 16, 1998: US05767948 (20 worldwide citation)

A lithographic device includes a machine frame which supports a substrate holder, a focusing system and a mask holder in a vertical direction. The substrate holder is displaceable parallel to a horizontal X-direction and a horizontal Y-direction perpendicular to the X-direction by a first positionin ...

Erik R Loopstra: Gas flushing system for use in lithographic apparatus. ASML Netherlands, Pillsbury Winthrop, April 29, 2003: US06555834 (20 worldwide citation)

In a lithographic apparatus using exposure radiation of a relatively short wavelength, e.g. 157 or 126 nm, a laminar flow of N