Patents by Inventor Yoshika Sakai

Yoshika Sakai 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: 6159652
    Abstract: Disclosed is an improved, chemically-amplifying positive resist composition for radiations, especially UV rays, deep-UV rays, excimer laser beams, X-rays, electron beams. The composition comprises (A) a resin component whose solubility in an alkaline aqueous solution is increased by the action of acids, (B) a compound which generates an acid when exposed to radiations, and (A) a resin component, (B) an acid-generating agent and (C) an organic carboxylic acid compound, in which said resin component (A) is a mixture comprising (a) a polyhydroxystyrene where from 10 to 60 mol % of the hydroxyl groups have been substituted by residues of a general formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group, R.sup.2 represents a methyl group or an ethyl group, and R.sup.3 represents a lower alkyl group having 1 to 4 carbon atoms;and (b) a polyhydroxystyrene where from 10 to 60 mol % of the hydroxyl groups have been substituted by tert-butoxy-carbonyloxy groups.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: December 12, 2000
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Mitsuru Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Etsuko Iguchi, Yoshika Sakai, Kazufumi Sato, Toshimasa Nakayama
  • Patent number: 5955240
    Abstract: Disclosed is an improved, chemically-amplifying positive resist composition for radiations, especially UV rays, deep-UV rays, excimer laser beams, X-rays, electron beams. The composition comprises (A) a resin component whose solubility in an alkaline aqueous solution is increased by the action of acids, (B) a chemical compound which generates an acid when exposed to radiations, and (C) an organic carboxylic acid compound and (D) an amine, in which said resin component (A) is a mixture comprising (a) a polyhydroxystyrene having a weight-average molecular weight of from 8,000 to 25,000 and a molecular weight distribution (Mw/Mn) of 1.5 or less where from 10 to 60 mol % of the hydroxyl groups have been substituted by residues of a general formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group, R.sup.2 represents a methyl group or an ethyl group, and R.sup.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: September 21, 1999
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazufumi Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5948589
    Abstract: Proposed is an improved chemical sensitization-type positive-working photoresist composition of high sensitivity and high pattern resolution for the photolithographic patterning works in the manufacture of semiconductor devices, which exhibits excellent post-exposure stability of the latent image formed by the pattern-wise exposure of the resist layer to actinic rays not to be affected relative to the fidelity of pattern reproduction and sensitivity even by standing for a length of time after the exposure to actinic rays before the subsequent processing treatment. The composition is characterized by the formulation of, in addition to an acid generating compound to release an acid by the irradiation with actinic rays and a resinous ingredient capable of being imparted with increased solubility in an aqueous alkaline developer solution by the presence of an acid, an amine compound such as triethylamine and a carboxylic acid such as salicylic acid in combination.
    Type: Grant
    Filed: June 4, 1996
    Date of Patent: September 7, 1999
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazufumi Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5945248
    Abstract: Proposed is a positive-working chemical-sensitization photoresist composition having advantages in respect of high resolution of patterning, high photosensitivity and orthogonal cross sectional profile of the patterned resist layer as well as in respect of little dependency of the performance on the nature of the substrate surface. The composition comprises:(A) 100 parts by weight of a film-forming hydroxyl-containing resin of a specified narrow molecular weight distribution substituted by acid-dissociable groups for a part of the hydroxyl groups which causes an increase of solubility in an aqueous alkaline solution by the interaction with an acid; and(B) from 0.5 to 20 parts by weight of a radiation-sensitive acid-generating agent which is a disulfone compound represented by the general formulaR.sup.1 --SO.sub.2 --(C.dbd.N.sub.2 ).sub.n --SO.sub.2 --R.sup.2,in which the subscript n is 0 or 1 and R.sup.1 and R.sup.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: August 31, 1999
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazuyuki Nitta, Kazufumi Sato, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5908730
    Abstract: Proposed is a positive- or negative-working chemical-sensitization photoresist composition having advantages in respect of the contrast and resolution of patterning, photosensitivity and cross sectional profile of the patterned resist layer as well as in respect of stability of the latent image formed by pattern-wise exposure to light before post-exposure baking treatment. The composition comprises: (A) 100 parts by weight of a film-forming resinous ingredient which causes a change, i.e. increase or decrease, of solubility in an aqueous alkaline solution by the interaction with an acid; and (B) from 0.5 to 20 parts by weight of a radiation-sensitive acid-generating agent which is a diazomethane compound represented by the general formulaR.sup.1 --SO.sub.2 --C(.dbd.N.sub.2)--SO.sub.2 --R.sup.2,in which R.sup.1 and R.sup.2 are each, independently from the other, a monovalent cyclic group substituted on the cyclic nucleus by an acid-dissociable group such as a tert-butoxycarbonyl and acetal groups.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: June 1, 1999
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazuyuki Nitta, Kazufumi Sato, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5874195
    Abstract: Proposed is a novel positive-working photoresist composition of the chemical sensitization type capable of giving a finely patterned resist layer having an excellent cross sectional profile even for a discretely isolated pattern with high sensitivity and high resolution. The composition comprises, besides (a) a compound generating an acid by the irradiation with actinic rays, (b) a resinous ingredient capable of being imparted with increased solubility in an alkaline developer solution in the presence of an acid and (c) an organic solvent which is a ketone, ether or ester as the basic ingredients of the chemical sensitization type photoresist compositions, (d) an N,N-dialkyl carboxylic acid amide such as N,N-dimethyl formamide and N,N-dimethyl acetamide in a specified proportion relative to the component (b).
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: February 23, 1999
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazufumi Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5856058
    Abstract: Proposed is a novel chemical sensitization-type positive-working photoresist composition used for the photolithographic patterning works in the manufacture of semiconductor devices exhibiting an excellent halation-preventing effect in the patternwise exposure to light. The composition comprises, in addition to conventional ingredients including an acid-generating agent capable of releasing an acid by the irradiation with actinic rays and a resinous ingredient capable of being imparted with increased solubility in an aqueous alkaline developer solution in the presence of an acid, a unique halation inhibitor which is an esterification product between a specified phenolic compound and a naphthoquinone-1,2-diazide sulfonic acid.
    Type: Grant
    Filed: June 7, 1996
    Date of Patent: January 5, 1999
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazufumi Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5854357
    Abstract: A polyhydroxystyrene where from 10 to 60 mol % of the hydroxyl groups have been substituted by tert-butoxycarbonyloxy groups.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: December 29, 1998
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Mitsuru Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Etsuko Iguchi, Yoshika Sakai, Kazufumi Sato, Toshimasa Nakayama
  • Patent number: 5817444
    Abstract: Proposed is a novel chemical-sensitization positive-working photoresist composition suitable for fine patterning of a resist layer in the manufacture of electronic devices. The composition is advantageous in various properties of photoresist composition without little dependency on the nature of the substrate surface, on which the photoresist layer is formed, with or without an antireflection undercoating layer. The most characteristic ingredient in the inventive composition is the film-forming resinous ingredient which is a combination of a first polyhydroxystyrene resin substituted by tetrahydropyranyl groups for the hydroxyl groups and a second hydroxystyrene resin substituted by alkoxyalkyl groups for the hydroxyl groups in a specified weight proportion of the first and second resins.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: October 6, 1998
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazufumi Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5770343
    Abstract: Proposed is a novel positive-working photoresist composition of the chemical sensitization type capable of giving a finely patterned resist layer having an excellent cross sectional profile even for a discretely isolated pattern with high sensitivity and high resolution. The composition comprises, besides (a) a compound generating an acid by the irradiation with actinic rays, (b) a resinous ingredient capable of being imparted with increased solubility in an alkaline developer solution in the presence of an acid and (c) an organic solvent which is a ketone, ether or ester as the basic ingredients of the chemical sensitization type photoresist compositions, (d) an N,N-dialkyl carboxylic acid amide such as N,N-dimethyl formamide and N,N-dimethyl acetamide in a specified proportion relative to the component (b).
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: June 23, 1998
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazufumi Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Yoshika Sakai, Toshimasa Nakayama
  • Patent number: 5736296
    Abstract: Disclosed is an improved, chemically-amplifying positive resist composition for radiations, especially UV rays, deep-UV rays, excimer laser beams, X-rays, electron beams. The composition comprises (A) a resin component whose solubility in an alkaline aqueous solution is increased by the action of acids, (B) a compound which generates an acid when exposed to radiations, and (A) a resin component, (B) an acid-generating agent and (C) an organic carboxylic acid compound, in which said resin component (A) is a mixture comprising (a) a polyhydroxystyrene where from 10 to 60 mol % of the hydroxyl groups have been substituted by residues of a general formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group, R.sup.2 represents a methyl group or an ethyl group, and R.sup.3 represents a lower alkyl group having 1 to 4 carbon atoms;and (b) a polyhydroxystyrene where from 10 to 60 mol % of the hydroxyl groups have been substituted by tert-butoxycarbonyloxy groups.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: April 7, 1998
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Mitsuru Sato, Kazuyuki Nitta, Akiyoshi Yamazaki, Etsuko Iguchi, Yoshika Sakai, Kazufumi Sato, Toshimasa Nakayama