Patents by Inventor Kousuke Doi

Kousuke Doi 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: 6300033
    Abstract: In a positive photoresist composition including (A) an alkali-soluble resin and (B) a photosensitizer, Ingredient (B) contains (B-1) a quinonediazide ester of, e.g., bis[2,5-dimethyl-3-(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane or 2,4-bis[4-hydroxy-3-(4-hydroxybenzyl)-5-methylbenzyl]-6-cyclohexylphenol, and (B-2) a quinonediazide ester of, e.g., methyl gallate or 2,2-bis(2,3,4-trihydroxyphenyl)propane. The composition exhibits high sensitivity and definition, and improved focal depth range properties and underexposure margin.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: October 9, 2001
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Takako Suzuki, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 6296992
    Abstract: A positive photoresist composition for forming a contact hole which comprises (A) an alkali-soluble resin; (B) a naphthoquinonediazide group-containing compound; and (C) a solvent, wherein the ingredient (B) comprises: at least one naphthoquinonediazidesulfonic ester of a polyphenol compound, where said polyphenol compound is composed of from 4 to 6 benzene rings each bonding via a methylene chain, each of the methylene chains is in a meta position to other methylene chains, and each of the benzene rings has a hydroxyl group is provided. According to tie present invention, a positive photoresist composition and a process for forming a contact hole can be provided each of which gives a contact hole pattern image in exact accordance with a mask pattern without dimple formation, in the contact hole forming technologies using the phaseshift method.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: October 2, 2001
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Masaki Kurihara, Satoshi Niikura, Miki Kobayashi, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama
  • Publication number: 20010024762
    Abstract: A phenol novolak resin has a peak intensity ratio of ortho-ortho bond (o-o)/ortho-para bond (o-p)/para-para bond (p-p) in a resin structure not substantially varying in each molecular weight fraction and has a weight average molecular weight (Mw) of 3000 to 20000 in terms of polystyrene, which peak intensity ratio is detected by 13C-NMR analysis. The phenol novolak resin can form both dense pattern and isolation pattern with good shapes in the formation of a fine resist pattern of not more than 0.35 &mgr;m and has satisfactory sensitivity, definition, and focal depth range properties, and has a resin composition being uniform in each molecular weight fraction. A process for producing the phenol novolak resin, and a positive photoresist composition using the resin are also provided.
    Type: Application
    Filed: February 28, 2001
    Publication date: September 27, 2001
    Inventors: Ken Miyagi, Yasuhide Ohuchi, Atsuko Hirata, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 6207340
    Abstract: A positive photoresist composition for forming a contact hole which comprises (A) an alkali-soluble resin; (B) a naphthoquinonediazide group-containing compound; and (C) a solvent, wherein the ingredient (B) comprises: at least one naphthoquinonediazidesulfonic ester of a polyphenol compound, where said polyphenol compound is composed of from 4 to 6 benzene rings each bonding via a methylene chain, each of the methylene chains is in a meta position to other methylene chains, and each of the benzene rings has a hydroxyl group is provided. According to the present invention, a positive photoresist composition and a process for forming a contact hole can be provided each of which gives a contact hole pattern image in exact accordance with a mask pattern without dimple formation, in the contact hole forming technologies using the phaseshift method.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: March 27, 2001
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Masaki Kurihara, Satoshi Niikura, Miki Kobayashi, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 6207788
    Abstract: A novolak resin precursor is composed of bonded phenolic moieties, one of the hydrogen atoms in the o- or p-positions relative to the hydroxy group of each phenolic moiety is substituted with an alkyl or alkenyl group having 1 to 3 carbon atoms, and the other two hydrogen atoms are bonded through methylene bonds. The content of ortho—ortho bonding is 30 to 70% relative to the number of total methylene bonds and the weight average molecular weight of the precursor is 300 to 10,000. A novolak resin is obtained from this precursor, and a positive photoresist composition comprises this novolak resin. The invention provides a positive photoresist composition that comprises less binuclear compounds, suppresses scum formation, is excellent in terms of definition and coating performance and provides a resist pattern having satisfactory heat resistance.
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: March 27, 2001
    Assignee: Tokyo Ohka Kogya Co., Ltd.
    Inventors: Ken Miyagi, Kousuke Doi, Ryuusaku Takahashi, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 6187500
    Abstract: In a positive photoresist composition including (A) an alkali-soluble novolak resin and (B) a naphthoquinonediazide ester, the alkali-soluble novolak resin is obtained synthetically by condensation of phenol compounds and an aldehyde or ketone, and the phenol compounds include, for example, 1% to 20% by mole of hydroquinone, 30% to 95% by mole of m-cresol and 2% to 50% by mole of 2,5-xylenol. Thus, a high-definition positive photoresist composition can be obtained, which inhibits the formation of scum, and is satisfactory in sensitivity, sectional shape, focal depth range and other properties even in a process for the formation of an ultrafine resist pattern of 0.30 &mgr;m or below by lithography using i-ray.
    Type: Grant
    Filed: November 2, 1999
    Date of Patent: February 13, 2001
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Ken Miyagi, Kousuke Doi, Atsuko Hirata, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 6177226
    Abstract: A positive photoresist composition for forming a contact hole which comprises (A) an alkali-soluble resin; (B) a naphthoquinonediazide group-containing compound; and (C) a solvent, wherein the ingredient (B) comprises: at least one naphthoquinonediazidesulfonic ester of a polyphenol compound, where said polyphenol compound is composed of from 4 to 6 benzene rings each bonding via a methylene chain, each of the methylene chains is in a meta position to other methylene chains, and each of the benzene rings has a hydroxyl group is provided. According to the present invention, a positive photoresist composition and a process for forming a contact hole can be provided each of which gives a contact hole pattern image in exact accordance with a mask pattern without dimple formation, in the contact hole forming technologies using the phaseshift method.
    Type: Grant
    Filed: April 29, 1998
    Date of Patent: January 23, 2001
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Masaki Kurihara, Satoshi Niikura, Miki Kobayashi, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 6127087
    Abstract: A positive photoresist composition comprises (A) an alkali-soluble resin, and (B) at least one quinonediazide group-containing compound in which part or all of the hydroxyl groups of a compound represented by the following formula (I) are esterified with a quinonediazidesulfonic acid: ##STR1## wherein each of R.sup.1 and R.sup.2 is an alkyl group having 1 to 5 carbon atoms, and "a" is 0 or 1. The present invention provides a positive photoresist composition which can form a resist pattern having high film residual rate, improved development contrast between exposed portions and unexposed portions, and satisfactory definition, exposure margin, focal depth range properties and sectional shape.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: October 3, 2000
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Miki Kobayashi, Kousuke Doi, Sachiko Tamura, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 6120969
    Abstract: Disclosed is, for example, bis(2,5-dimethyl-3-(2-hydroxy-5-ethylbenzyl)-4-hydroxyphenyl)methane and quinonediazide ester thereof. These are used for positive photoresist compositions. According to the invention, positive photoresist compositions having a high definition, a high sensitivity and a large exposure margin can be provided.
    Type: Grant
    Filed: April 2, 1999
    Date of Patent: September 19, 2000
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Mitsuo Hagihara, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama, Tetsuya Nakajima
  • Patent number: 6030741
    Abstract: The present invention provides a positive resist composition and method capable of achieving a resist pattern whose photosensitivity is less variable relative to its thickness, which exhibits small thickness reduction even when the pattern is fine, is capable of coping with irregularities in the exposure value since it has a wide focal-depth range, and exhibits reduced size-deviation from the mask size. The positive resist composition comprises (A) an alkali-soluble resin, (B) a quinonediazide-group-containing compound, and (C) an organic solvent, wherein the ingredient (C) is a mixture solvent containing (i) 2-heptanone, (ii) ethyl lactate, and (iii) a high-boiling organic solvent having a boiling point of 200 to 350.degree. C. The above-described resist pattern can be formed by using the positive resist composition.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: February 29, 2000
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kousuke Doi, Takako Suzuki, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5853948
    Abstract: A positive photoresist composition comprising (A) an alkali-soluble resin; (B) a quinonediazido group containing compound; and (C) at least one sulfonyl halide represented by the following general formula (I):R.sup.1 --SO.sub.2 --X (I)where R.sup.1 is an alkyl group, a substituted alkyl group, an alkenyl group, an aryl group or a substituted aryl group; X is a halogen atom, as well as a multilayer resist material using this composition. Very fine (<0.4 .mu.m) resist patterns can be formed that have high feature or edge integrity, that provide good contrast between exposed and unexposed areas after development and that assure a wider margin of exposure, better depth-of-focus characteristics and sharper cross-sectional profiles.
    Type: Grant
    Filed: October 29, 1997
    Date of Patent: December 29, 1998
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Atsushi Sawano, Junichi Mizuta, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5738968
    Abstract: The present invention provides a positive photoresist composition exhibiting superior sensitivity, definition and thermostability, and in addition, having excellent focal depth range properties. The positive photoresist composition comprises (A) an alkali-soluble resin; (B) a quinonediazide group-containing compound; and (C), for example, bis(4-hydroxy-2,3,5-trimethylphenyl)-2-hydroxyphenylmethane.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: April 14, 1998
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Hiroshi Hosoda, Taku Hirayama, Kousuke Doi, Satoshi Niikura, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5702861
    Abstract: A positive photoresist composition comprising: (A) an alkali-soluble resin; (B) a quinone diazide group-containing compound; and (C) at least one compound selected from the polyhydroxy compounds, such as 1,3-bis?2-(5-cyclohexyl-2-methyl-4-hydroxyphenyl)-2-propyl!benzene. The composition of the present invention exhibits excellent image contrast between exposed portions and unexposed portions, and actualizes formation of a resist pattern with excellent resolution, exposure range, and focal depth range.
    Type: Grant
    Filed: January 30, 1997
    Date of Patent: December 30, 1997
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Satoshi Niikura, Takako Suzuki, Kousuke Doi, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5601961
    Abstract: Disclosed is an improved positive-working photoresist composition comprising an alkali-soluble resin as a film-forming agent and a quinone diazide group-containing compound as a photosensitive agent. The most characteristic feature of the inventive composition consists in the unique formulation of the alkali-soluble resin which is a combination of two or three kinds of novolac resins selected from novolac resins (a), (b1) or (b2) and (c1) or (c2), each of which is characterized by the unique formulation of the phenolic compounds as a mixture to be subjected to a condensation reaction with an aldehyde compound to form the novolac resin.
    Type: Grant
    Filed: March 29, 1995
    Date of Patent: February 11, 1997
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kazuhiko Nakayama, Taku Nakao, Kousuke Doi, Nobuo Tokutake, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5501936
    Abstract: An improved positive-working photoresist composition useful in the fine patterning work of a resist layer is proposed which is capable of giving a patterned resist layer having excellent resolution, heat resistance and orthogonality of the cross sectional profile of a line pattern with a high sensitivity to actinic rays and a wide range of the focusing depth. The photoresist composition comprises, as a uniform mixture in the form of a solution, (a) an alkali-soluble novolac resin, (b) a naphthoquinone-1,2-diazido group-containing compound as a photosensitizing ingredient and (c) a specific phenolic triphenyl methane compound substituted by cyclohexyl groups on two of the phenyl groups, such as bis(3-cyclohexyl-4-hydroxy-6-methylphenyl)-3,4-dihydroxyphenyl methane or bis(3-cyclohexyl-6-hydroxy-4-methylphenyl)-3,4-dihydroxyphenyl methane, in a specified amount.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: March 26, 1996
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Hiroshi Hosoda, Remi Numata, Kousuke Doi, Nobuo Tokutake, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5478692
    Abstract: Proposed is a novel positive-working photoresist composition suitable for use in the fine patterning works in the manufacture of electronic devices and capable of exhibiting excellent performance with high resolution, high sensitivity, wide range of focusing depth, large exposure dose latitude and other characteristics. The photoresist composition is formulated, in addition to the basic ingredients of an alkali-soluble novolac resin as a film-forming agent and photosensitive ingredient such as an ester of naphthoquinone-1,2-diazide sulfonic acid and a polyhydroxy compound, with a limited amount of 4,4'-bis(dialkylamino) benzophenone, e.g., 4,4'-bis(diethylamino) benzophenone, preferably, in combination with a polyhydroxy compound such as 4,6-bis[1-methyl-1-(4-hydroxyphenyl)ethyl]-1,3-dihydroxy phenol.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: December 26, 1995
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kousuke Doi, Taku Nakao, Remi Numata, Nobuo Tokutake, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5434031
    Abstract: Disclosed is a positive-working photoresist composition suitable for use in the photolithographic fine patterning work in the manufacture of electronic devices such as VLSIs. The composition comprises, in addition to an alkali-soluble novolac resin as a film-forming ingredient and an esterification product of naphthoquinone-1,2-diazide sulfonic acid as a photosensitive ingredient, a unique additive compound which is an alkyl or aralkyl ester of 2-hydroxy benzoic acid, such as benzyl salicylate, or a phenol compound substituted at least one alkyl group such as 2-tert-butyl-4-methyl phenol. By virtue of the addition of this unique additive, the inventive photoresist composition exhibits an excellent performance of suppressing the standing wave effect in addition to the excellent photosensitivity, resolving power and depth of focusing in the patterning exposure to light as well as good heat resistance of the patterned resist layer.
    Type: Grant
    Filed: November 17, 1993
    Date of Patent: July 18, 1995
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Taku Nakao, Remi Numata, Kousuke Doi, Nobuo Tokutake, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5401605
    Abstract: Proposed is a positive-working photosensitive resin composition suitable as a photoresist in the photolithographic patterning work for the manufacture of, for example, semiconductor devices having excellent storage stability and capable of giving a patterned resist layer having excellent contrast of the images, orthogonality of the cross sectional profile of line patterns and heat resistance along with a satisfactorily high photosensitivity and large focusing latitude. The composition comprises, in admixture with an alkali-soluble novolac resin as a film-forming agent, a photosensitizing agent which is an esterification product of a specific tris(hydroxyphenyl) methane compound of which two of the hydroxyphenyl groups each have a cyclohexyl group bonded thereto at a specified position with at least one naphthoquinone-1,2-diazide sulfonyl group as the esterifying group.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: March 28, 1995
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kousuke Doi, Hiroshi Hosoda, Kouichi Takahashi, Nobuo Tokutake, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5384228
    Abstract: A novel alkali-developable photosensitive resin composition, which is suitable for use as a photoresist composition for fine patterning in the manufacture of various electronic devices, is proposed. The photosensitive resin composition comprises, as the essential ingredients, (a) an alkali-soluble novolac resin as the film-forming ingredient and (b) a very specific compound which is a 1,2-quinone diazide sulfonic acid ester of a condensation product having a weight-average molecular weight of 400 to 2000 obtained by the condensation reaction between phenol and a hydroxybenzaldehyde in the presence of an acidic catalyst as the photosensitizing agent. By virtue of the formulation with this specific photosensitizer, the resist layer formed from the inventive composition has a greatly increased focusing latitude in addition to the excellent sensitivity, resolution and heat resistance.
    Type: Grant
    Filed: October 8, 1993
    Date of Patent: January 24, 1995
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kousuke Doi, Satoshi Niikura, Nobuo Tokutake, Hidekatsu Kohara, Toshimasa Nakayama