Patents by Inventor Tetsuya Tatsumi

Tetsuya Tatsumi 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).

  • Publication number: 20070298615
    Abstract: A pattern forming method is provided. The pattern forming method includes a first step of forming a resist pattern including a lactone group-containing skeleton above an etched layer provided on a substrate; a second step of performing plasma processing using a hydrogen-containing gas to lower a glass transition temperature or a softening point of the resist pattern; and a third step of transferring the resist pattern after the plasma processing to the etched layer by etching, and forming the pattern of the etched layer.
    Type: Application
    Filed: January 30, 2007
    Publication date: December 27, 2007
    Inventors: Nobuyuki Matsuzawa, Atsuhiro Ando, Eriko Matsui, Yuko Yamaguchi, Katsuhisa Kugimiya, Tetsuya Tatsumi, Salam Kazi, Takeshi Iwai, Makiko Irie
  • Publication number: 20070026681
    Abstract: Provision of a process capable of preferably etching particularly PtMn used for a pin layer of an MRAM is an object: a dry etching method for performing dry etching on a layer including platinum and/or manganese by using pulse plasma and a production method of an MRAM, wherein the dry etching method is applied to processing of the pin layer. The MRAM is configured to have a memory portion comprising a magnetic memory element composed of tunnel magnetoresistive effect element formed by stacking a magnetic fixed layer having a fixed magnetization direction, a tunnel barrier layer and a magnetic layer capable of changing the magnetization direction.
    Type: Application
    Filed: August 26, 2004
    Publication date: February 1, 2007
    Applicant: SONY CORPORATION
    Inventors: Toshiaki Shiraiwa, Tetsuya Tatsumi, Seiji Samukawa
  • Publication number: 20050247672
    Abstract: A method for plasma etching an insulating layer by using a fluorocarbon etching gas, the method including controlling the sheath potential Vs (or ion accelerating voltage) that appears on the outermost surface of the plasma surrounding parts of the plasma etching equipment in response to the value (Fc) of F0/C0, where C0 and F0 each denote the total amount of carbon atoms and fluorine atoms constituting the fluorocarbon etching gas, so as to avoid deposition of residues on the plasma surrounding parts. This method permits stable plasma etching.
    Type: Application
    Filed: April 20, 2005
    Publication date: November 10, 2005
    Inventor: Tetsuya Tatsumi
  • Publication number: 20050019962
    Abstract: Disclosed is a plasma monitoring method for detecting the amount of atomic radicals generated by dissociation of a molecular raw material gas during a plasma processing conducted by introducing the molecular raw material gas and a rare gas into a process atmosphere, wherein the amount of the atomic radicals is predicted from the dissociation degree of the molecular raw material gas determined from the partial pressure of the molecular raw material gas in the process atmosphere, the luminous intensity of the rare gas, and the partial pressure of the rare gas in the process atmosphere, whereby the amount of the specific atomic radicals can be monitored easily and accurately.
    Type: Application
    Filed: June 25, 2004
    Publication date: January 27, 2005
    Inventor: Tetsuya Tatsumi
  • Patent number: 5660681
    Abstract: A method for processing a layer of a silicon-based material on a wafer by which a sidewall protective film may be removed sufficiently and efficiently. An etching gas capable of yielding chlorine- or bromine-based chemical species and oxygen-based chemical species is used for dry etching a polycide film formed on a gate insulating film, plasma processing with an oxygen-based gas is then carried out for ashing the resist mask and removing carbonaceous components in the sidewall protective film. In addition, the sidewall protective film is oxidized so that the composition to that of stoichiometrically stable SiO.sub.2 is approached. Subsequently, the modified sidewall protective film is removed by processing with a dilute hydrofluoric acid solution. Since this sufficiently removes the sidewall protective film, it becomes possible to reduce the amount of dust and to improve coverage of a film to be formed by the next step.
    Type: Grant
    Filed: August 19, 1996
    Date of Patent: August 26, 1997
    Assignee: Sony Corporation
    Inventors: Seiichi Fukuda, Tetsuya Tatsumi
  • Patent number: 5378311
    Abstract: A method in which in case different kinds of processing are consecutively conducted in a single chamber of a plasma device, a residual portion of a processing gas used in one process is prevented from affecting a next process, is disclosed. A chemical species resulting from the processing gas in one process is prevented from being generated in forming a plasma in the next processing, by introducing an inactive gas after the processing gas used in one processing is exhausted once, or by introducing the inactive gas while exhausting the processing gas, or by cyclically repeating exhaust of the processing gas and introduction of the inactive gas, prior to the next process. The degree of exhaust may be monitored on the basis of an emission spectrum of the plasma.
    Type: Grant
    Filed: November 24, 1993
    Date of Patent: January 3, 1995
    Assignee: Sony Corporation
    Inventors: Tetsuji Nagayama, Tetsuya Tatsumi
  • Patent number: 5368686
    Abstract: A dry etching method for anisotropically etching a polycide film without using chlorofluorocarbon (CFC). For instance, in a W polycide gate electrode forming process, a W polycide film is etched by using sulfur fluorides, like S.sub.2 F.sub.2, with a high S/F ratio (i.e. the ratio of the number of sulfur atoms to that of fluorine atoms). In a first step, at least the upper WSi.sub.x layer of the W polycide film is etched with the wafer kept at temperatures between -20.degree. C. and room temperature or with non-depositional fluorine based compounds like SF.sub.6 added to etching gas, thus decreasing the S/F ratio of the etching system. This first step promotes elimination of WF.sub.x and reduces the quantity of free sulfur. Therefore, WF.sub.x is inhibited from reacting with sulfur to form WS.sub.x for deposition in excessive quantities on the sidewalls of the WSi.sub.x pattern, thus preventing occurrence of critical dimension losses between the resist mask and the W polycide gate electrode.
    Type: Grant
    Filed: June 16, 1992
    Date of Patent: November 29, 1994
    Assignee: Sony Corporation
    Inventors: Tetsuya Tatsumi, Tetsuji Nagayama
  • Patent number: 5362361
    Abstract: A dry etching method for anisotropic etching of target material layers at low temperature without using CFC-based gases whereby excessive sidewall protection effects are inhibited and etching reproducibility is improved. In dry etching using S.sub.2 F.sub.2, sidewalls are protected by depositing sulfur (S) dissociated in plasma on the sidewalls. However, the sulfur thus formed will also deposit on the inside wall of an etching chamber, increasing with time the S/F ratio of an etching reaction system. To prevent this, a first heater is used to heat the lower inside wall of a bell jar of an magnetically-enhanced microwave plasma etching apparatus during etching. Then, a second heater and a third heater are used to heat the outer periphery of a wafer supporting electrode and the exposed portion of a cooling pipe, respectively, so that the atmosphere in the bell jar is kept clean with an appropriate S/F ratio.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: November 8, 1994
    Assignee: Sony Corporation
    Inventor: Tetsuya Tatsumi
  • Patent number: 5354421
    Abstract: A dry etching method for performing anisotropic etching of a layer of a silicon based material without using a chlorofluorocarbon gas, is proposed. Sulfur halides yielding free sulfur (S) into a plasma under conditions of dissociation by electrical discharge, such as S.sub.2 F.sub.2 or S.sub.2 Cl.sub.2, are used as main components of the etching gas. This S is used for sidewall protection and for improving selectivity during etching, and is removed by sublimation by heating the wafer after etching. Although etching may be achieved by S.sub.2 F.sub.2 alone, suitable measures may preferably be used to increase the S/X ratio of an etching reaction system, which is a ratio of the number of atoms of S to that of X or a halogen, because the layer of the silicon based material is highly susceptible to halogen radicals. Specifically, optimum results may be obtained by (a) adding H.sub.2, H.sub.2 S or SiH.sub.
    Type: Grant
    Filed: January 22, 1992
    Date of Patent: October 11, 1994
    Assignee: Sony Corporation
    Inventors: Tetsuya Tatsumi, Shingo Kadomura, Tetsuji Nagayama
  • Patent number: 5266154
    Abstract: A dry etching method whereby underlying layer selectivity and anisotropy may be prevented from deteriorating due to excessive radicals in an over-etching process. In the etching chamber of an ordinary magnetically-enhanced microwave plasma etching apparatus, the so-called ECR position at which the ECR condition is established is a very small region, where ionization current has the highest density and the most uniform direction in ECR plasma. On the downstream side of the ECR position is the after-glow region of ECR plasma with a low plasma density. According to the present invention, the etching chamber is provided on part of the inner sidewall thereof with an Si-based material layer capable of consuming halogen radicals while a lifting and lowering means is provided for varying the distance between a target wafer and the ECR position.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: November 30, 1993
    Assignee: Sony Corporation
    Inventor: Tetsuya Tatsumi
  • Patent number: 5227341
    Abstract: An improved method of manufacturing a semiconductor device includes forming an insulating layer on a substrate, depositing a metal film layer on the insulating layer and depositing a photoresist layer on the metal film layer. The photoresist layer is formed with openings through which a predetermined surface of the metal film layer is exposed. The predetermined surface of the metal film layer is subjected to dry etching so that an underlying portion of the insulating layer is exposed. The remaining portion of the photoresist layer is then subjected to ashing by using an isopropyl alcohol-containing gas to expose the surface of said metal film layer.
    Type: Grant
    Filed: February 6, 1992
    Date of Patent: July 13, 1993
    Assignee: Sony Corporation
    Inventors: Yukihiro Kamide, Shingo Kadomura, Tetsuya Tatsumi
  • Patent number: 5211790
    Abstract: A method for anisotropic etching of a layer of a silicon-based material, using an SF.sub.6 gas, a versatile etching gas, is proposed. Sulfur (S) is used as a sidewall protection substance. This sulfur is not supplied into an etching reaction system on discharge dissociation of the etching gas, but is supplied by being sublimed off on heating from the inner wall surface of the etching chamber on which it is previously grown from a gaseous phase. Specifically, the S.sub.2 F.sub.2 gas is introduced while a predetermined region of the inner wall surface of the etching chamber is cooled, and preliminary discharge is carried out to deposit sulfur on the region. A SF.sub.6 containing etching gas is introduced into the chamber and the above mentioned region is heated for subliming S and simultaneously etching the layer of the silicon-based material. With this method, there is no necessity of using a specific etching gas capable of yielding free S in the plasma under discharge dissociating conditions.
    Type: Grant
    Filed: February 26, 1992
    Date of Patent: May 18, 1993
    Assignee: Sony Corporation
    Inventor: Tetsuya Tatsumi
  • Patent number: 5200028
    Abstract: A process is disclosed for etching a silicon-based structure comprised of a silicon layer and a high-melting silicide layer. Good shaping results from etching of the two layers with use of two gaseous mixtures having their respective different ratios of a hydrogen bromide gas and a fluorine radical-donating gas. Separate etching is possible of the silicon layer with a hydrogen bromide gas and of the silicide layer with a gaseous mixture of the above type. A silicon-containing layer is also etched with a hydrogen gas alone with the end point of etching being precisely detected.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: April 6, 1993
    Assignee: Sony Corporation
    Inventor: Tetsuya Tatsumi
  • Patent number: 5180464
    Abstract: Disclosed is a dry etching method by which a polycide film consisting of a refractory metal silicide layer and a polysilicon layer are stacked one upon the other may be etched with high anisotropy, low pollution, high selectivity and high speed without using flon gases.According to the method of the present invention, an etching gas containing a fluorine base gas mixed at least with HBr is used for etching the polycide film for realizing anisotropic processing under sidewall protection by a reaction product of mainly the resist material and Br.Overetching for uniform processing in the wafer plane is performed with the use approximately solely of the fluorine base gas or HBr for realizing a high speed and improving substrate selectivity.The overetching step is preceded by oxygen plasma treatment for oxidizing the reaction product and intensifying side wall protective effects while improving anisotropy.
    Type: Grant
    Filed: January 22, 1991
    Date of Patent: January 19, 1993
    Assignee: Sony Corporation
    Inventors: Tetsuya Tatsumi, Shingo Kadomura