United States Patent 4,200,668
April 29, 1980

Method of Repairing a Defective Photomask
Paul D. Segal
Ching-Ping Wong

Filed September 5, 1978
Image of US PATENT 4,200,668

Abstract of the Disclosure

A method of repairing pin holes in a defective photomask such as one comprising a patterned chromium film on a glass substrate comprises depositing an adhesion promoting film such as siloxane on the surface of the photomask, then depositing a solvent soluble layer such as a photoresist layer over the adhesion promoting layer, a window is then formed through the layers and underlying photomask in the area of the pin hole by burning through these layers by means of a laser. The exposed areas of the window are etched and a metallic film is deposited over the exposed surfaces. Finally, the photomask is treated with solvent for removing the solvent soluble photoresist which also causes the metal film deposited thereon to be removed in all areas except the area of the window.
Figure descriptions: cover graphic

  • side cross-sectional elevations of a photomask showing the defect repair process steps.

 Citations [54]:
2,447,836 08/1948 Beeber et al. 3,650,796 03/1972 Jackson et al. 3,748,975 07/1973 Tarabocchia 4,107,351 08/1978 James et al.
National Museum of American History
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