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Illumination device

  • US 5,296,891 A
  • Filed: 10/29/1992
  • Issued: 03/22/1994
  • Est. Priority Date: 05/02/1990
  • Status: Expired due to Term
First Claim
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1. An illumination device for producing models used for manufacturing electronic elements, or for direct illumination of wafers or substrates during the photolithographic steeps required for their production, or for direct illumination of structures including light-sensitive layers, comprising:

  • a pulsed laser light source;

    a pattern generator;

    said pattern generator including an optical Schlieren system and an active, matrix-addressable surface light modulator;

    said surface light modulator including a reflective surface having addressed surface areas which diffract incident light and non-addressed surface areas which reflect incident light;

    said Schlieren system comprising a Schlieren lens arranged on a side of said surface light modulator, a projection lens facing away from said surface light modulator, and a mirror device arranged between said lenses for directing light coming from said light source onto said reflective surface on said surface light modulator;

    means for focussing the light coming from said light source onto said mirror device;

    wherein said Schlieren lens is arranged from said surface light modulator at a short distance relative to the focal length of said Schlieren lens;

    a filter device arranged between said Schlieren lens and said projection leans, said filter device having a structural design to filter out undiffracted light reflected by said non-addressed surface areas of said surface light modulator and to permit diffracted light reflected by said addressed surface areas to pass via said projection lens to the model, or to the electronic element, or to the structure;

    a displaceable positioning table for securing the model, or the electronic element, or the structure so that a sharp image of said addressed surface areas of said surface light modulator is formed on the model, or on the electronic element, or on the structure;

    said pulse laser light source having a pulse duration shorter than the minimum structural dimension of the model to be produced, or of the electronic element, or of the structure divided by the displacement rate of said positioning table; and

    during the displacement of the positioning table, the model, or the electronic element, or the structure is put together using a plurality of successive partial images by adequate addressing of said surface light modulator.

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