Patents by Inventor M. Dalil Rahman

M. Dalil Rahman 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).

  • Trace metal ion reduction by Ion Exchange Pack
    Patent number: 5955570
    Abstract: The present invention provides methods for solutions having a very low level of metal ions, utilizing a specially designed Ion Exchange Pack. A method is also provided for producing photoresist composition having a very low level of metal ions from novolak resins purified in a process using such an Ion Exchange Pack.
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: September 21, 1999
    Assignee: Clariant International Ltd.
    Inventors: M. Dalil Rahman, Carlo R. Spilletti, Michelle M. Cook
  • Fractionated novolak resin copolymer and photoresist composition therefrom
    Patent number: 5928836
    Abstract: The present invention provides a method for producing a film forming, fractionated novolak resin copolymer exhibiting fast photospeed and superior performance in a photoresist composition. A method is also provided for producing photoresist composition from such a fractionated novolak resin copolymer and for producing semiconductor devices using such a photoresist composition.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: July 27, 1999
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Stanley F. Wanat, Michelle M. Cook, Douglas S. McKenzie, Sunit S. Dixit
  • Fractionated novolak resin from cresol-formaldehyde reaction mixture and photoresist composition therefrom
    Patent number: 5910559
    Abstract: The present invention provides a method for producing a film forming, fractionated novolak resin having consistent molecular weight and superior performance in photoresist composition, by isolating such novolak resin fractions without high temperature distillation. A method is also provided for producing photoresist composition from such a fractionated novolak resin and for producing semiconductor devices using such a photoresist composition.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: June 8, 1999
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Ping-Hung Lu, Michelle Cook
  • Isolation of novolak resin without high temperature distillation and photoresist composition therefrom
    Patent number: 5863700
    Abstract: The present invention provides a method for producing a water insoluble, aqueous alkali soluble novolak resins having consistent molecular weight and superior performance in photoresist composition, by isolating such novolak resin without high temperature distillation. A method is also provided for producing photoresist composition from such a novolak resin and for producing semiconductor devices using such a photoresist composition.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: January 26, 1999
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Ping-Hung Lu
  • Image formation utilizing photosensitive compositions containing low metal content p-cresol oligomers
    Patent number: 5858627
    Abstract: Process for producing a photosensitizer comprising a diazo ester of a p-cresol oligomer where at least one of the hydroxy groups on the p-cresol ring has been esterified with diazo-sulfonyl chloride comprising from about 60 to 100 mole % 2,1,4 or 2,1,5-diazo sulfonyl chloride, or a mixture thereof; and a photoresist comprising an admixture of the photosensitizer, which is present in the photoresist composition in an amount sufficient to uniformly photosensitive the photoresist composition, a water insoluble, aqueous alkali soluble novolak resin, the novolak resin being present in the photoresist composition in an amount sufficient to form a substantially uniform photoresist composition, and a suitable solvent.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: January 12, 1999
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Dinesh N. Khanna, Daniel Aubin, Douglas McKenzie
  • Quinonediazide positive photoresist utilizing mixed solvent consisting essentially of 3-methyl-3-methoxy butanol and propylene glycol alkyl ether acetate
    Patent number: 5853947
    Abstract: A photosensitive positive working photosensitive composition suitable for use as a photoresist, which comprises an admixture of at least one water insoluble, aqueous alkali soluble, film forming novolak resin; at least one o-diazonaphthoquinone photosensitizer; and a photoresist solvent mixture comprising a propylene glycol alkyl ether acetate and 3-methyl-3-methoxy butanol and process for producing such a composition.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: December 29, 1998
    Assignee: Clariant Finance (BVI) Limited
    Inventors: Stanley F. Wanat, M. Dalil Rahman, Dinesh N. Khanna, Daniel P. Aubin, Sunit S. Dixit
  • Fractionated novolak resin and photoresist composition therefrom
    Patent number: 5853954
    Abstract: The present invention provides a method for producing a film forming, fractionated novolak resin having consistent molecular weight and superior performance in photoresist composition, by isolating such novolak resin fractions without high temperature distillation. A method is also provided for producing photoresist composition from such a fractionated novolak resin and for producing semiconductor devices using such a photoresist composition.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: December 29, 1998
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Ping-Hung Lu
  • Quinone diazide compositions containing low metals p-cresol oligomers and process of producing the composition
    Patent number: 5837417
    Abstract: Process for producing a photosensitizer comprising a diazo ester of a p-cresol oligomer where at least one of the hydroxy groups on the p-cresol ring has been esterified with diazo-sulfonyl chloride comprising from about 60 to 100 mole % 2,1,4 or 2,1,5-diazo sulfonyl chloride, or a mixture thereof; and a photoresist comprising an admixture of the photosensitizer, which is present in the photoresist composition in an amount sufficient to uniformly photosensitive the photoresist composition, a water insoluble, aqueous alkali soluble novolak resin, the novolak resin being present in the photoresist composition in an amount sufficient to form a substantially uniform photoresist composition, and a suitable solvent.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: November 17, 1998
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Dinesh N. Khanna, Daniel Aubin, Douglas McKenzie
  • Low metals perfluorooctanoic acid and top anti-reflective coatings for photoresists
    Patent number: 5830990
    Abstract: The present invention provides methods for producing top anti-reflective coating compositions having a very low level of metal ions, utilizing a specially washed and modified ion exchange resin. A method is also provided for producing semiconductor devices using such ion exchange treated top anti-reflective coating compositions.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: November 3, 1998
    Assignee: Clariant Finance (BVI) Limited
    Inventor: M. Dalil Rahman
  • Isolation of novolak resin by low temperature sub surface forced steam distillation
    Patent number: 5750632
    Abstract: A water insoluble, aqueous alkali soluble novolak resin, process for producing such a novolak resin, a photoresist containing such a novolak resin, and a method for producing a semiconductor device, wherein the resin is isolated by sub surface forced steam distillation.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: May 12, 1998
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Daniel Aubin
  • Process for producing surfactant having a low metal ion level and developer produced therefrom
    Patent number: 5750031
    Abstract: The present invention provides a process for producing a developer containing a surfactant which contains a very low level of metal ions.
    Type: Grant
    Filed: September 26, 1995
    Date of Patent: May 12, 1998
    Assignee: Clariant Finance (BVI) Limited
    Inventors: M. Dalil Rahman, Daniel P. Aubin
  • Fractionation of phenol formaldehyde condensate and photoresist compositions produced therefrom
    Patent number: 5739265
    Abstract: A process for producing a water insoluble, aqueous alkali soluble, film forming novolak resin having low metal ions, made by the fractionation of a phenol formaldehyde condensation product, a process for producing a resin a photoresist composition of superior quality containing such novolak resin, and a method for producing a semiconductor device using such photoresist composition.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: April 14, 1998
    Assignee: Clariant Finance (BVI) Ltd.
    Inventors: M. Dalil Rahman, Daniel P. Aubin, Dinesh N. Khanna, Sunit S. Dixit
  • Fractionation of phenol formaldehyde condensate and photoresist compositions produced therefrom
    Patent number: 5693749
    Abstract: A process for producing a water insoluble, aqueous alkali soluble, film forming novolak resin fraction having a low metal ion content, made by the fractionation of a phenol formaldehyde condensation product, a process for producing a photoresist compositions containing such a novolak resin, and a method for producing a semiconductor device using such a photoresist composition.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: December 2, 1997
    Assignee: Hoechst Celanese Corporation
    Inventors: M. Dalil Rahman, Daniel P. Aubin, Dinesh N. Khanna, Sunit S. Dixit
  • Method of using a Lewis base to control molecular weight of novolak resins
    Patent number: 5688893
    Abstract: The present invention provides methods for producing water insoluble, aqueous alkali soluble novolak resins having a precise and consistent molecular weight, by adjusting the concentration of Lewis base. A method is also provided for producing photoresist composition from such novolak resins and for producing semiconductor devices using such photoresist compositions.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: November 18, 1997
    Assignee: Hoechst Celanese Corporation
    Inventors: M. Dalil Rahman, Daniel P. Aubin, Dana L. Durham, Ralph R. Dammel
  • Metal ion reduction in novolak resin solution using an anion exchange resin
    Patent number: 5686561
    Abstract: The present invention provides methods for producing water insoluble, aqueous alkali soluble novolak resins having a very low level of metal ions, utilizing a specially treated anion exchange resin. A method is also provided for producing photoresist composition having a very low level of metal ions from such novolak resins and for producing semiconductor devices using such photoresist compositions.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: November 11, 1997
    Assignee: Hoechst Celanese Corporation
    Inventor: M. Dalil Rahman
  • Acidic ion exchange resin as a catalyst to synthesize a novolak resin and photoresist composition therefrom
    Patent number: 5665517
    Abstract: The present invention provides methods for producing water insoluble, aqueous alkali soluble novolak resins having consistent molecular weight and a very low level of metal ions, utilizing a solid acid condensation catalyst. A method is also provided for producing photoresist composition having a very low level of metal ions from such novolak resins and for producing semiconductor devices using such photoresist compositions.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: September 9, 1997
    Assignee: Hoechst Celanese Corporation
    Inventors: M. Dalil Rahman, Daniel P. Aubin, Elaine G. Kokinda, Dana L. Durham
  • Low metal ion containing 4,4'-[1-[4-[1-(4-Hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphe nol and photoresist compositions therefrom
    Patent number: 5656413
    Abstract: The present invention provides methods for producing TPPA having low level of metal ions, utilizing treated ion exchange resins. A method is also provided for producing photoresist composition having a very low level of metal ions from such TPPA for producing semiconductor devices using such photoresist compositions.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: August 12, 1997
    Assignee: Hoechst Celanese Corporation
    Inventors: M. Dalil Rahman, Daniel P. Aubin
  • Metal ion reduction in top anti-reflective coatings for photoresisis
    Patent number: 5624789
    Abstract: The present invention provides methods for producing top anti-reflective coating compositions having a very low level of metal ions, utilizing specially treated ion exchange resins. A method is also provided for producing semiconductor devices using such top anti-reflective coating compositions.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: April 29, 1997
    Assignee: Hoechst Celanese Corporation
    Inventors: M. Dalil Rahman, Dana L. Durham
  • Metal ion reduction in novolak resins solution in PGMEA by chelating ion exchange resin
    Patent number: 5614352
    Abstract: The present invention provides methods for producing water insoluble, aqueous alkali soluble novolak resins having a very low level of metal ions, utilizing treated chelated ion exchange resins to make the neutral ammonium salt or acid form. A method is also provided for producing photoresist composition having a very low level of metal ions from such novolak resins and for producing semiconductor devices using such photoresist compositions.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: March 25, 1997
    Assignee: Hoechst Celanese Corporation
    Inventor: M. Dalil Rahman
  • Using a Lewis base to control molecular weight of novolak resins
    Patent number: 5614349
    Abstract: The present invention provides methods for producing water insoluble, aqueous alkali soluble novolak resins having a precise and consistent molecular weight, by adjusting the concentration of Lewis base. A method is also provided for producing photoresist composition from such novolak resins and for producing semiconductor devices using such photoresist compositions.
    Type: Grant
    Filed: December 29, 1992
    Date of Patent: March 25, 1997
    Assignee: Hoechst Celanese Corporation
    Inventors: M. Dalil Rahman, Daniel P. Aubin, Dana L. Durham, Ralph R. Dammel