Illumination device using a pulsed laser source a Schlieren optical system and a matrix addressable surface light modulator for producing images with undifracted light

US5486851A · kind A · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Andreas Gehner · Duisburg, DE
• Gunther Hess · Linz, AT
• Heinz Kück · Stuttgart, DE
• Holger Vogt · Mülheim, DE

Key dates

• Filing date: Jul 19, 1994
• Grant date: Jan 23, 1996
• Expiry date: Jul 19, 2014

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70358
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An illumination device for producing models used for manufacturing electronic elements, or for direct illumination of wafers or substrates during the photolithographic steps required for their production, or for direct illumination of structures including light-sensitive layers, comprises a pulsed laser light source and a pattern generator. The pattern generator includes an optical Schlieren system and an active, matrix-addressable surface light modulator. The Schlieren system comprises a Schlieren lens arranged on a side of the surface light modulator, a projection lens facing away from the surface light modulator, and a mirror device which is arranged between the lenses for directing light coming from the light source onto the reflective surface on the surface light modulator. The Schlieren lens is arranged from the surface light modulator at a short distance relative to the focal length of the lens. A filter device is arranged in the diffraction image plane of the virtual point light source between the Schlieren lens and the projection lens, the filter device having a structural design of such a nature that it will either filter out the diffracted light reflected by the addresse…