Patents by Inventor Nageshwer Rao Bantu

Nageshwer Rao Bantu 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).

  • Preparation of partially cross-linked polymers and their use in pattern formation
    Patent number: 6262181
    Abstract: This invention relates to a process for generating a organically soluble partially cross-linked acid labile polymer according to the present invention comprises the steps of providing a polymer with one or more monomer units, wherein at least one of the monomer units contain one or more pendant COOH or hydroxyl groups; and reacting said polymer with a polyvinyl ether in the presence of a acid catalyst to form links between at least two polymer chains. The resulting polymer can be used as a component in a photoresist formulation.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: July 17, 2001
    Assignee: Arch Specialty Chemicals, Inc.
    Inventors: Nageshwer Rao Bantu, Donald Frank Perry, Jacqueline Marie Marshall, Timothy Michael Holt
  • Photoresist develop and strip solvent compositions and method for their use
    Patent number: 6127097
    Abstract: Simple, environmentally friendly developers and strippers are disclosed for free radical-initiated, addition polymerizable resists, cationically cured resists and solder masks and photoresists. Both the developers and the strippers include benzyl alcohol, optionally also including a minor amount of methanol, ethanol, isopropyl alcohol, propylene glycol monomethylacetate, ethylene glycol monomethyl ether, formamide, nitromethane, propylene oxide, or methyl ethyl ketone, acetone and water.
    Type: Grant
    Filed: March 18, 1997
    Date of Patent: October 3, 2000
    Assignee: International Business Machines Corporation
    Inventors: Nageshwer Rao Bantu, Anilkumar Chinuprasad Bhatt, Ashwinkumar Chinuprasad Bhatt, Joseph Alphonse Kotylo, Gerald Walter Jones, Robert John Owen, Kostas Papathomas, Anaya Kumar Vardya
  • Preparation of partially cross-linked polymers and their use in pattern formation
    Patent number: 6072006
    Abstract: This invention relates to a process for generating a organically soluble partially cross-linked acid labile polymer according to the present invention comprises the steps of providing a polymer with one or more monomer units, wherein at least one of the monomer units contain one or more pendant COOH or hydroxyl groups; and reacting said polymer with a polyvinyl ether in the presence of a acid catalyst to form links between at least two polymer chains. The resulting polymer can be used as a component in a photoresist formulation.
    Type: Grant
    Filed: November 6, 1998
    Date of Patent: June 6, 2000
    Assignee: Arch Specialty Chemicals, Inc.
    Inventors: Nageshwer Rao Bantu, Donald Frank Perry, Jacqueline Marie Marshall, Timothy Michael Holt
  • Acid Scavengers for use in chemically amplified photoresists
    Patent number: 5733705
    Abstract: Proton sponge, berberine, and cetyltrimethyl ammonium hydroxide base compounds are used as additives to chemically amplified photoresists based on modified polyhydroxystyrene (PHS). The base additives scavenge free acids from the photoresist in order to preserve the acid labile moieties on the modified PHS polymer. The base additives are well suited to industrial processing conditions, do not react with the photoacid compounds in the photoresist composition to form byproducts which would hinder photoresist performance, and extend the shelf-life of the photoresist composition. In addition, the proton sponge and berberine base additives have a different absorption spectra than the modified PHS polymer, therefore, the quantity of base additive within the photoresist can be easily assayed and controlled.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: March 31, 1998
    Assignee: International Business Machines Corporation
    Inventors: Nageshwer Rao Bantu, William Ross Brunsvold, George Joseph Hefferon, Wu-Song Huang, Ahmad D. Katnani, Mahmoud M. Khofasteh, Ratnam Sooriyakumaran, Dominic Changwon Yang
  • Acid scavengers for use in chemically amplified photoresists
    Patent number: 5667938
    Abstract: Proton sponge, berberine, and cetyltrimethyl ammonium hydroxide base compounds are used as additives to chemically amplified photoresists based on modified polyhydroxystyrene (PHS). The base additives scavenge free acids from the photoresist in order to preserve the acid labile moieties on the modified PHS polymer. The base additives are well suited to industrial processing conditions, do not react with the photoacid compounds in the photoresist composition to form byproducts which would hinder photoresist performance, and extend the shelf-life of the photoresist composition. In addition, the proton sponge and berberine base additives have a different absorption spectra than the modified PHS polymer, therefore, the quantity of base additive within the photoresist can be easily assayed and controlled.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: September 16, 1997
    Assignee: International Business Machines Corporation
    Inventors: Nageshwer Rao Bantu, William Ross Brunsvold, George Joseph Hefferon, Wu-Song Huang, Ahmad D. Katnani, Mahmoud M. Khojasteh, Ratnam Sooriyakumaran, Dominic Changwon Yang