Patents by Inventor Richard Keosian

Richard Keosian 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).

  • Patent number: 6060212
    Abstract: A polymer that when used with a suitable photoacid generator (PAG) forms a positive working photoresist. The polymer comprises of a tartaric polyanhydride backbone, an acetal protected 1,2 diol group; and a fused ring acetal group pendant to the backbone. The acetal protected .alpha.-hydroxy anhydride backbone structure, undergoes an efficient photoacid catalyzed cleavage, which gives rise to small molecular weight fragments which are readily dissolved in an aqueous base developer. This high contrast in solubility allows high resolution images to be produced. The fused rings offer etch resistance and can be comprised of either an adamantone or norcamphor ring structure. With the addition of a commercially available photo acid generator, the polymer formulation forms a positive working photoresist that offers high contrast and resolution.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: May 9, 2000
    Assignee: Clariant Finance (BVI) Limited
    Inventors: Iain McCulloch, Anthony J. East, Ming Kang, Richard Keosian, Hyun-Nam Yoon
  • Patent number: 5998092
    Abstract: A water soluble polymer that when used with a suitable photoacid generator (PAG) forms a negative working water soluble photoresist. The polymer comprises of a backbone, such as polyvinyl ether, coupled by a linkage group to an acetal protected .beta.-keto acid group. With the addition of a number of commercially available photo acid generators, the polymer formulation forms a negative working photoresist that is water soluble. Exposure to radiation will cause a photoacid catalyzed deprotection of the acetal group, yielding a .beta.-keto acid which, upon heating, will undergo decarboxylation, which results in a water insoluble photoproduct and evolution of CO.sub.2 as a byproduct. This photochemically induced reaction results in a significant change in the polymer solubility parameter, and the product is no longer soluble in water.
    Type: Grant
    Filed: May 27, 1998
    Date of Patent: December 7, 1999
    Assignee: Clariant International, Ltd.
    Inventors: Iain McCulloch, Anthony J. East, Ming Kang, Richard Keosian, Hyun-Nam Yoon