International Business Machines Corporation

Hsing Hsiung Chen

Krishna Gandhi Sachdev

Charles Hampton Perry

Lawrence D David

Donald Rene Wall

Umar M Ahmad

Peter H Berasi

A method is provided for etching and removing extraneous molybdenum or debris on ceramic substrates such as semiconductor devices and also for molybdenum etching in the fabrication of molybdenum photomasks. The method employs a multi-step process using an acidic aqueous solution of a ferric salt to remove (etch) the molybdenum debris followed by contacting the treated substrate with an organic quaternary ammonium hydroxide to remove any molybdenum black oxides which may have formed on the exposed surface of treated molybdenum features in ceramic substrates. The method is environmentally safe and the waste solutions may be easily waste treated for example by precipitating the ferric salts as ferric hydroxide and removing anions such as sulfate by precipitation with lime. The method replaces the currently used method of employing ferricyanide salts which create serious hazardous waste disposal and environmental problems.

Method of etching molybdenum metal from substrates

A molybdenum mask for use in the sputter deposition of electrically conductive materials on preselected areas of a substrate is coated with a transition metal carbide. The carbide protects the metal images defined on the mask from degradation during mask cleaning and related processes, thereby dramatically extending the usable service life of the mask. The present invention overcomes the problem of reduced usable life of a molybdenum mask used in sputter coating and similar evaporative deposition processing.

Corrosion resistant molybdenum mask

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Poughkeepsie, NY, United States of America

Hsing Hsiung Chen