Patents by Inventor Ahmad D. Katnani

Ahmad D. Katnani 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: 6140015
    Abstract: Acid-catalyzed positive photoresist compositions having generally improved performance (especially photoresist compositions having improved contrast (solubility differential), shrinkage and processing kinetics on radiation exposure) are obtained by use of polymers containing pendant polar-functionalized aromatic groups and acid-labile light crosslinking. The photoresist compositions also may contain a photosensitive acid-generating component as well as a solvent and possibly other auxiliary components. The polymers may contain other functional groups or components designed to impart alkaline-solubility, to provide alkaline-solubility protection in the absence of generated acid, etc.The photoresist compositions can be used to create patterned photoresist structures and further to make conductive, semiconductive or insulative structures by photolithography.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: October 31, 2000
    Assignee: International Business Machines Corporation
    Inventors: Pushkara R. Varanasi, Ahmad D. Katnani, Mahmoud M. Khojasteh, Ranee W. Kwong
  • Patent number: 6114082
    Abstract: A photoresist composition is disclosed having both negative tone and positive tone responses, giving rise to spaces being formed in the areas of diffraction which are exposed to intermediate amounts of radiation energy. This resist material may be used to print doughnut shapes or may be subjected to a second masking step, to print lines. Additionally, larger and smaller features may be obtained using a gray-scale filter in the reticle, to create larger areas of intermediate exposure areas.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: September 5, 2000
    Assignee: International Business Machines Corporation
    Inventors: Mark C. Hakey, Steven J. Holmes, David V. Horak, Ahmad D. Katnani, Niranjan M. Patel, Paul A. Rabidoux
  • Patent number: 6103447
    Abstract: The present invention is directed to a high-performance irradiation sensitive positive-tone resist and to a method of formulating the same. In one aspect, the polymer resin composition of the present invention comprises a blend of at least two miscible aqueous base soluble polymer resins, wherein one of said aqueous base soluble polymer resins of said blend is partially protected with a high activation energy protecting group and the other aqueous base soluble polymer resin of said blend is partially protected with a low activation energy protecting group. A chemically amplified resist system comprising said polymer resin composition; at least one acid generator; and a solvent is also provided herein.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: August 15, 2000
    Assignee: International Business Machines Corp.
    Inventors: Kuang-Jung Chen, Ronald A. DellaGuardia, Wu-Song Huang, Ahmad D. Katnani, Mahmoud M. Khojasteh, Qinghuang Lin
  • Patent number: 6087064
    Abstract: Novel silsesquioxane polymers are formed by methods which avoid the use of BBr.sub.3. The novel silsesquioxane polymers are especially useful in negative photoresist compositions and photolithographic processes. Alternatively, improved silsesquioxane polymer-containing negative photoresist compositions are obtained by using a polymer component containing a blend of silsesquioxane polymer and non-silsesquioxane polymer. The photoresist compositions provide improved dissolution characteristics enabling the use of 0.26 N TMAH developer. The photoresist compositions also provide improved thermal characteristics enabling use of higher processing temperatures. The photoresist compositions are especially useful in a multilayer photolithographic processes and are capable of producing high resolution.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: July 11, 2000
    Assignee: International Business Machines Corporation
    Inventors: Qinghuang Lin, Marie Angelopoulos, Ahmad D. Katnani, Ratnam Sooriyakumaran
  • Patent number: 6043003
    Abstract: The present invention relates to chemically amplified resists and resist systems wherein some of the polar functional groups of the aqueous base soluble polymer or copolymers are protected with a cyclic aliphatic ketal protecting group such as methoxycyclohexanyl. The resists and the resist systems of the present invention containing the new protecting group have improved shelf-life and vacuum stability as compared to the prior art resists. Thus, the resists of the present invention are highly useful in e-beam lithographic applications.
    Type: Grant
    Filed: July 16, 1999
    Date of Patent: March 28, 2000
    Assignee: International Business Machines Corporation
    Inventors: James J. Bucchignano, Wu-Song Huang, Ahmad D. Katnani, Kim Y. Lee, Wayne M. Moreau, Karen E. Petrillo
  • Patent number: 6037097
    Abstract: The present invention relates to chemically amplified resists and resist systems wherein some of the polar functional groups of the aqueous base soluble polymer or copolymers are protected with a cyclic aliphatic ketal protecting group such as methoxycyclohexanyl. The resists and the resist systems of the present invention containing the new protecting group have improved shelf-life and vacuum stability as compared to the prior art resists. Thus, the resists of the present invention are highly useful in e-beam lithographic applications.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: March 14, 2000
    Assignee: International Business Machines Corporation
    Inventors: James J. Bucchignano, Wu-Song Huang, Ahmad D. Katnani, Kim Y. Lee, Wayne M. Moreau, Karen E. Petrillo
  • Patent number: 5955222
    Abstract: A method of making a rim-type phase shift mask comprising the steps of: providing a substrate having opposing first and second surfaces, the first surface being at least partially covered with a first layer of material that substantially blocks the transmission therethrough of electromagnetic radiation of the predetermined range of wavelengths; forming a plurality of openings extending through the first layer so as to expose underlying portions of the first surface of the substrate; depositing a layer of hybrid photoresist on the first layer; exposing the second surface of the substrate to electromagnetic radiation to activate the desired portions of the hybrid photoresist; developing the photoresist, thereby exposing portions underlying the resist; and etching the exposed portions of the substrate is disclosed.
    Type: Grant
    Filed: December 3, 1996
    Date of Patent: September 21, 1999
    Assignee: International Business Machines Corporation
    Inventors: Michael Straight Hibbs, Steven John Holmes, Ahmad D. Katnani, Wayne Martin Moreau, Niranjan Mohanlal Patel
  • Patent number: 5919597
    Abstract: Methods are provided to prepare photoresists without isolation of various components, i.e. in a "one-pot" procedure. Preferred one-pot preparation methods of the invention include preparing a photoresist resin binder in a selected photoresist solvent and, without isolation of the resin binder from the solvent, adding a photoactive component and any other desired photoresist materials to the resin binder in solution to thereby provide a liquid photoresist composition in the solvent in which the resin binder was prepared. The invention also provides novel methods for synthesizing resist resin binders, particularly phenolic polymers that contain phenolic OH groups covalently bonded to another moiety such as acid labile groups or inert blocking groups.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: July 6, 1999
    Assignees: IBM Corporation of Armonk, Shipley Company, L.L.C. of Marlborough
    Inventors: Roger F. Sinta, Uday Kumar, George W. Orsula, James I. T. Fahey, William R. Brunsvold, Wu-Song Huang, Ahmad D. Katnani, Ronald W. Nunes, Mahmoud M. Khojasteh
  • 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
  • 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
  • Patent number: 5609989
    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: June 6, 1995
    Date of Patent: March 11, 1997
    Assignee: International Business Machines, Corporation
    Inventors: Nageshwer R. Bantu, William R. Brunsvold, George J. Hefferon, Wu-Song Huang, Ahmad D. Katnani, Mahmoud M. Khojasteh, Ratnam Sooriyakumaran, Dominic C. Yang
  • Patent number: 5296332
    Abstract: High sensitivity, high contrast, heat-stable resist compositions for use in deep UV, i-line e-beam and x-ray lithography. These compositions comprise a film-forming polymer having aromatic rings activated for electrophilic substitution, an acid catalyzable crosslinking agent which forms a hydroxy-stabilized carbonium ion, and a photoacid generator. The compositions are aqueous base developable.
    Type: Grant
    Filed: November 22, 1991
    Date of Patent: March 22, 1994
    Assignee: International Business Machines Corporation
    Inventors: Harbans S. Sachdev, Willard E. Conley, Premlatha Jagannathan, Ahmad D. Katnani, Ranee W. Kwong, Leo L. Linehan, Steve S. Muira, Randolph J. Smith