Patents by Inventor Kohei Kawamura
Kohei Kawamura 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).
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Patent number: 6155200Abstract: In an ECR plasma generator, radio frequency ranging from 3 to 300 MHz is applied from a radio frequency power supply to an electrode which is provided in a chamber having an exhaust system and which serves as a shower head for gas introduction, and power is supplied to a coil provided at the outer periphery of the chamber, so as to form a magnetic field an integer number of times as large as a resonant magnetic field corresponding to the applied radio frequency, parallel with the direction of an electric field and to generate ECR plasma in an atmosphere of the supplied process gas.Type: GrantFiled: July 2, 1998Date of Patent: December 5, 2000Assignees: Tokyo Electron Limited, Yasuhiro HoriikeInventors: Yasuhiro Horiike, Kohei Kawamura
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Patent number: 5958258Abstract: A susceptor on which a wafer is placed, and an upper electrode are arranged in the processing chamber of an etching apparatus to oppose each other. An optical transmission window is disposed in the side wall of the processing chamber. The upper electrode and the susceptor are supplied with RF powers from a second RF power supply and a first RF power supply, respectively, to excite a plasma in the processing chamber. Emission of the plasma is detected by an optical detector through the optical transmission window, and data is sampled. In a CPU, the sampling data is subjected to fitting based on the Weibull distribution function, thus obtaining an approximate equation, and furthermore the differential equation of the approximate equation is obtained. The virtual end point of etching is expected from the approximate equation and differential equation.Type: GrantFiled: June 17, 1998Date of Patent: September 28, 1999Assignee: Tokyo Electron Yamanashi LimitedInventors: Hiroyuki Ishihara, Kohei Kawamura
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Patent number: 5531834Abstract: A plasma film forming apparatus comprises gas supply means for feeding a processing gas into a processing chamber, a first electrode opposed to an object of processing in the processing chamber, a second electrode in the form of a flat coil facing the first electrode across the object of processing, pressure regulating means for keeping the pressure in the processing chamber at 0.1 Torr or below, heating means for heating the object of processing to a predetermined temperature, and application means for applying radio-frequency power between the first and second electrodes, whereby the processing gas is converted into a plasma such that a film is formed on the surface of the object of processing through reaction of ions or active seeds in the plasma. When radio-frequency power is applied between the pair of electrodes, a radio-frequency electric field is formed. Since one of the electrodes is the flat coil, however, a magnetic field is formed.Type: GrantFiled: July 12, 1994Date of Patent: July 2, 1996Assignee: Tokyo Electron Kabushiki KaishaInventors: Shuichi Ishizuka, Kohei Kawamura, Jiro Hata, Akira Suzuki
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Patent number: 5522934Abstract: A plasma processing apparatus comprises a susceptor for supporting a target object to be processed having a target surface to be processed in a process vessel, a plurality of process gas supply nozzles for supplying a process gas for the target object into the process vessel, and an RF coil for generating an electromagnetic wave in the process vessel to generate a plasma of the process gas. The supplying nozzles have process gas injection holes formed at a plurality of levels in a direction substantially perpendicular to the target surface of the target object in the process vessel, and the gas injection holes located at an upper level are closer to a center of the target surface than gas injection holes located at a lower level.Type: GrantFiled: April 25, 1995Date of Patent: June 4, 1996Assignee: Tokyo Electron LimitedInventors: Akira Suzuki, Shuichi Ishizuka, Kohei Kawamura, Jiro Hata
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Patent number: 5476182Abstract: An etching apparatus for etching an insulating film of an object to be processed having the insulating film comprises a first chamber into which an inert gas is introduced, a plasma generating section for converting the inert gas to a plasma in the first chamber, a second chamber, which communicates with the first chamber, for receiving a reactive gas for etching the insulating film and generating radicals of the reactive gas therein, and a support electrode for supporting the object to be processed in the second chamber and attracting ions in the plasma of the inert gas to the object to be processed. The radicals is generated when the reactive gas introduced into the second chamber is excited by the plasma of the inert gas diffused from the first chamber to the second chamber. The insulating film and the radicals react with each other by the assist of the ions of the inert gas, thereby etching the insulating film.Type: GrantFiled: September 8, 1993Date of Patent: December 19, 1995Assignee: Tokyo Electron LimitedInventors: Shuichi Ishizuka, Kohei Kawamura, Jiro Hata
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Patent number: 5308791Abstract: An apparatus for processing the surface of an Si wafer includes a vacuum cleaning chamber in which said Si wafer is housed. He gas is supplied into the cleaning chamber and micro-wave and magnetic field are applied to the He gas to generate excited species which emit vacuum ultraviolet. The vacuum ultraviolet is radiated onto the wafer surface to enable its energy to cut bonds between Si atoms of said wafer and O atoms and forming a natural oxide film on the wafer surface. Ar gas is also supplied into the cleaning chamber to create ions of said Ar gas due to energy added from said excited species. Said ions are supplied onto the wafer surface to form floating potential above said wafer surface. Said ions collide against said wafer surface to eliminate O atoms from said wafer surface. A process chamber is connected to the cleaning chamber through a load lock chamber. Al film is formed on the wafer surface, from which the natural oxide film has been eliminated, in the process chamber.Type: GrantFiled: March 9, 1992Date of Patent: May 3, 1994Assignees: Tokyo Electron Limited, Yasuhiro HoriikeInventors: Yasuhiro Horiike, Kohei Kawamura
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Patent number: 5290609Abstract: A dielectric film of a capacitor is formed using the plasma CVD apparatus. A thin Ta layer is deposited on a semiconductor wafer by using Ta(N(CH.sub.3).sub.2).sub.5 gas and H.sub.2 radicals. The thin Ta layer is then oxidized by O.sub.2 radicals to form a thin Ta.sub.2 O.sub.5 layer. An Si.sub.3 N.sub.4 layer is then formed on the Ta.sub.2 O.sub.5 layer by using SiH.sub.4 and NH.sub.3 gases. The Ta.sub.2 O.sub.5 layer and the Si.sub.3 N.sub.4 layer are alternately laminated one upon the other several times to form a dielectric film of laminated structure. The dielectric film can thus have a composition close to the stoichiometric composition and it can be made high in dielectric constant and excellent in withstand voltage.Type: GrantFiled: March 9, 1992Date of Patent: March 1, 1994Assignees: Tokyo Electron Limited, Yasuhiro HoriikeInventors: Yasuhiro Horiike, Kohei Kawamura
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Patent number: 5252892Abstract: A plasma processing apparatus includes a filament mounted in an electron generation chamber for producing plasma of a discharge gas, thereby generating electrons. The electrons are supplied from the electron generation chamber into an ion generation chamber through electron passage hole between both chambers to produce plasma of a processing gas inside the ion generation chamber. The chambers are formed of conductive ceramics to constitute electrodes.Type: GrantFiled: October 31, 1991Date of Patent: October 12, 1993Assignee: Tokyo Electron LimitedInventors: Akira Koshiishi, Kohei Kawamura, Masahiko Matsudo, Naoki Takayama
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Patent number: 5101110Abstract: An ion generator comprises an electron-generating chamber and an ion-generating chamber. Ions are generated by introducing a raw material gas into the ion-generating chamber and irradiating the raw material gas with electrodes generated in the electron-generating chamber. The ions, thus generated, are drawn by ion-collecting electrodes and guided out of the ion-generating chamber through a slit formed in the ion output section of the ion-generating chamber. That corner of the ion-generating chamber which faces the ion-collecting electrodes is curved, and that outer wall of the ion-generating chamber which faces the ion-collecting electrodes is specular. With this structure, an undesirable spark discharge does not easily take place with reference to the ion-collecting electrodes, so that damage to the structural components of the ion generator is suppressed. Further, the ion output section is removable from the main body of the ion-generating chamber.Type: GrantFiled: November 9, 1990Date of Patent: March 31, 1992Assignee: Tokyo Electron LimitedInventors: Masahiko Matsudo, Akira Koshiishi, Naoki Takayama, Kohei Kawamura
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Patent number: 5089747Abstract: An electron beam excitation ion source includes a housing having an ion generation chamber therein, a port for supplying a discharge gas to the ion generation chamber, a porous electrode for supplying accelerated electrons to the ion generation chamber from an electron generation chamber, causing the accelerated electrons to collide against the discharge gas to generate a plasma containing ions in the ion generation chamber. The housing have an ion extraction slit port through which the ions are extracted from the ion generation chamber outside the housing. An electrode is formed around the ion extraction port, for causing a local discharge around the ion extraction port so as to guide the ions in the plasma to the ion extraction port.Type: GrantFiled: February 16, 1990Date of Patent: February 18, 1992Assignee: Tokyo Electron LimitedInventors: Akira Koshiishi, Kohei Kawamura, Naoki Takayama
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Patent number: 5083061Abstract: An ion source according to the present invention includes a first chamber, including a main chamber having an electron generating arrangement therein, and a sub-chamber communicating with the main chamber through a nozzle, for producing a first plasma by a discharge. A supply is also provided for supplying a first gas for a discharge into the main chamber, as well as an electron extracting arrangement for extracting electrons from the first plasma. Also included are a second chamber for producing a second plasma by discharge excitation of the extracted electrons and ionizing a second gas as a source gas, a further supply for supplying the second gas into the second chamber, and a magnetic field generator for generating a magnetic field for guiding the extracted electrons toward the second chamber. The electron extracting arrangement includes an electrode between the sub-chamber and the second chamber.Type: GrantFiled: November 15, 1990Date of Patent: January 21, 1992Assignee: Tokyo Electron LimitedInventors: Akira Koshiishi, Kohei Kawamura
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Patent number: 5028791Abstract: An electron beam excitation ion source comprises a housing having an ion generation chamber therein. A discharge gas and an accelerated electrons are introduced into the ion generation chamber, causing the accelerated electrons to collide against the discharge gas to generate a plasma containing ions in the ion generation chamber. The housing includes an ion extraction port through which the ions are extracted from the ion generation chamber outside the housing and an electron reflecting member exposed in the ion generation chamber to reflect the electrons.Type: GrantFiled: February 28, 1990Date of Patent: July 2, 1991Assignee: Tokyo Electron Ltd.Inventors: Akira Koshiishi, Kohei Kawamura, Masahiko Matsudo, Naoki Takayama
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Patent number: 4749912Abstract: An ion-producing apparatus comprises an electron-producing vessel having an electron-producing chamber, an ion-producing vessel having an ion-producing chamber communicating with the electron-producing chamber, a cathode provided at one end of the electron-producing vessel, an accelerating electrode provided within the ion-producing chamber, for allowing passage of electrons, an anode provided between the cathode and the accelerating electrode, and a power supply circuit for providing a potential difference between the cathode and the anode, thereby to produce electrons in the gap between the cathode and the anode. A vacuum pump is provided for evacuating gas from the ion-producing chamber. A partition is provided within the electron-producing vessel, between the cathode and the anode to divide the electron-producing vessel into a cathode-side chamber and an anode-side chamber, and hinders a gas flow from the cathode-side chamber to the anode-side chamber to apply a pressure difference between both chambers.Type: GrantFiled: May 27, 1987Date of Patent: June 7, 1988Assignees: Rikagaku Kenkyusho, Tokyo Electron LimitedInventors: Tamio Hara, Manabu Hamagaki, Yoshinobu Aoyagi, Susumu Namba, Nobuo Ishii, Naoki Takayama, Kohei Kawamura