Patents by Inventor Donald C. Mammato

Donald C. Mammato has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method of producing an image reversal negative photoresist having a photo-labile blocked imide
    Patent number: 5019488
    Abstract: A method for producing a negative image by coating a substrate with a photosensitive layer containing a blocked hydrophobic polymer capable of deblocking in the presence of an acid, and an oxime sulfonate ester or o-quinone-4-sulfonyl-containing diazide, then imagewise exposing, treating with a gaseous base, removing excess base, overall flood exposing, baking and developing with an aqueous alkaline solution.
    Type: Grant
    Filed: April 24, 1990
    Date of Patent: May 28, 1991
    Assignee: Hoechst Celanese Corporation
    Inventors: Donald C. Mammato, Sangya Jain, Dana Durham, Mark A. Spak, Douglas A. Usifer, Michael McFarland
  • Positive photoresist processing with mid U-V range exposure
    Patent number: 4596763
    Abstract: The invention provides a method for producing a positive working photoresist which comprises coating at least one novolak resin, and 1-naphthalenesulfonic acid, 3-diazo-3,4-dihydro-4-oxo-,4-benzoyl-1,2,3-benzenetriyl ester onto a substrate, exposing to a u.v. light source having a wavelength of less than 380 nanometers and developing with an aqueous alkaline solution.
    Type: Grant
    Filed: October 1, 1984
    Date of Patent: June 24, 1986
    Assignee: American Hoechst Corporation
    Inventors: John DiCarlo, Jonas St. Alban, Donald C. Mammato, Bruce M. Stevens
  • Light-sensitive trisester of O-quinone diazide containing composition for the preparation of a positive-acting photoresist
    Patent number: 4588670
    Abstract: A light sensitive composition for the preparation of a positive acting photoresist which is a mixture of an alkali soluble resin and a compound of the formula ##STR1## wherein X is a naphthoquinone-(1,2)-diazide-(2)-sulfonyl residue.
    Type: Grant
    Filed: February 28, 1985
    Date of Patent: May 13, 1986
    Assignee: American Hoechst Corporation
    Inventors: Michael Kelly, Donald C. Mammato, Dana Durham, Sangya Jain, Lawrence Crane