Patents by Inventor Masafumi Kubota

Masafumi Kubota 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: 20030057451
    Abstract: On a silicon substrate is formed a silicon dioxide film and then hemispherical grains made of silicon, each having an extremely small diameter, are deposited thereon by LPCVD. After annealing the hemispherical grains, the silicon dioxide film is etched using the hemispherical grains as a first dotted mask, thereby forming a second dotted mask composed of the silicon dioxide film. The resulting second dotted mask is used to etch the silicon substrate to a specified depth from the surface thereof, thereby forming an aggregate of semiconductor micro-needles. Since the diameter of each of the semiconductor micro-needles is sufficiently small to cause the quantum size effects as well as has only small size variations, remarkable quantum size effects can be obtained. Therefore, it becomes possible to constitute a semiconductor apparatus with a high information-processing function by using the aggregate of semiconductor micro-needles (quantized region).
    Type: Application
    Filed: October 22, 2002
    Publication date: March 27, 2003
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Koji Eriguchi, Masafumi Kubota, Masaaki Niwa, Noboru Nomura
  • Patent number: 6489629
    Abstract: On a silicon substrate is formed a silicon dioxide film and then hemispherical grains made of silicon, each having an extremely small diameter, are deposited thereon by LPCVD. After annealing the hemispherical grains, the silicon dioxide film is etched using the hemispherical grains as a first dotted mask, thereby forming a second dotted mask composed of the silicon dioxide film. The resulting second dotted mask is used to etch the silicon substrate to a specified depth from the surface thereof, thereby forming an aggregate of semiconductor micro-needles. Since the diameter of each of the semiconductor micro-needles is sufficiently small to cause the quantum size effects as well as has only small size variations, remarkable quantum size effects can be obtained. Therefore, it becomes possible to constitute a semiconductor apparatus with a high information-processing function by using the aggregate of semiconductor micro-needles (quantized region).
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: December 3, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Koji Eriguchi, Masafumi Kubota, Masaaki Niwa, Noboru Nomura
  • Publication number: 20020050651
    Abstract: A semiconductor device includes metal interconnects made from a multi-layer film composed of a first metal film formed on a semiconductor substrate with an insulating film sandwiched therebetween and a second metal film deposited on the first metal film. An interlayer insulating film having a via hole is formed on the metal interconnects. A third metal film is selectively grown on the second metal film within the via hole, so that a plug can be formed from the third metal film.
    Type: Application
    Filed: October 19, 2001
    Publication date: May 2, 2002
    Inventors: Hideo Nakagawa, Eiji Tamaoka, Masafumi Kubota, Tetsuya Ueda
  • Patent number: 6210593
    Abstract: In etching a target film to be etched antecedently, an etching rate is measured at each of the peripheral and central portions of the target film. If the etching rate is higher at the peripheral portion of the target film to be etched antecedently than at the central portion thereof, a focus ring positioned around a wafer is moved upward in etching a target film to be etched subsequently, so that the quantity of radicals arriving at the peripheral portion of the target film to be etched subsequently is decreased. If the etching rate is lower at the peripheral portion of the target film to be etched antecedently than at the central portion thereof, the focus ring is moved downward in etching the target film to be etched subsequently, so that the quantity of radicals arriving at the peripheral portion of the target film to be etched subsequently is increased.
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: April 3, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsuhiro Ohkuni, Masafumi Kubota
  • Patent number: 6177291
    Abstract: On a silicon substrate is formed a silicon dioxide film and then hemispherical grains made of silicon. each having an extremely small diameter, are deposited thereon by LPCVD. After annealing the hemispherical grains, the silicon dioxide film is etched using the hemispherical grains as a first dotted mask, thereby forming a second dotted mask composed of the silicon dioxide film. The resulting second dotted mask is used to etch the silicon substrate to a specified depth from the surface thereof, thereby forming an aggregate of semiconductor micro-needles. Since the diameter of each of the semiconductor micro-needles is sufficiently small to cause the quantum size effects as well as has only small size variations, remarkable quantum size effects can be obtained. Therefore, it becomes possible to constitute a semiconductor apparatus with a high information-processing function by using the aggregate of semiconductor micro-needles (quantized region).
    Type: Grant
    Filed: February 8, 2000
    Date of Patent: January 23, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Koji Eriguchi, Masafumi Kubota, Masaaki Niwa, Noboru Nomura
  • Patent number: 6087197
    Abstract: On a silicon substrate is formed a silicon dioxide film and then hemispherical grains made of silicon, each having an extremely small diameter, are deposited thereon by LPCVD. After annealing the hemispherical grains, the silicon dioxide film is etched using the hemispherical grains as a first dotted mask, thereby forming a second dotted mask composed of the silicon dioxide film. The resulting second dotted mask is used to etch the silicon substrate to a specified depth from the surface thereof, thereby forming an aggregate of semiconductor micro-needles. Since the diameter of each of the semiconductor micro-needles is sufficiently small to cause the quantum size effects as well as has only small size variations, remarkable quantum size effects can be obtained. Therefore, it becomes possible to constitute a semiconductor apparatus with a high information-processing function by using the aggregate of semiconductor micro-needles (quantized region).
    Type: Grant
    Filed: January 8, 1999
    Date of Patent: July 11, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Koji Eriguchi, Masafumi Kubota, Masaaki Niwa, Noboru Nomura
  • Patent number: 6033928
    Abstract: On a silicon substrate is formed a silicon dioxide film and then hemispherical grains made of silicon, each having an extremely small diameter, are deposited thereon by LPCVD. After annealing the hemispherical grains, the silicon dioxide film is etched using the hemispherical grains as a first dotted mask, thereby forming a second dotted mask composed of the silicon dioxide film. The resulting second dotted mask is used to etch the silicon substrate to a specified depth from the surface thereof, thereby forming an aggregate of semiconductor micro-needles. Since the diameter of each of the semiconductor micro-needles is sufficiently small to cause the quantum size effects as well as has only small size variations, remarkable quantum size effects can be obtained. Therefore, it becomes possible to constitute a semiconductor apparatus with a high information-processing function by using the aggregate of semiconductor micro-needles (quantized region).
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: March 7, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Koji Eriguchi, Masafumi Kubota, Masaaki Niwa, Noboru Nomura
  • Patent number: 5928528
    Abstract: A reactive gas supplied to a chamber 1 is put into plasma by supplying radio frequency power to the chamber 1 intermittently or while repeating high and low levels alternately and a specimen A in the chamber 1 is treated by the plasma. A positive pulse-like bias voltage synchronized with a period in which the radio frequency power is not supplied or a period in which low-level power is supplied is applied to the specimen A for preventing charging.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: July 27, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masafumi Kubota, Shigenori Hayashi, Michinari Yamanaka, Kenji Harafuji
  • Patent number: 5869402
    Abstract: A reactive gas is introduced into a vacuum chamber by a gas controller so that a plasma is generated in a plasma generation region. Subsequently, high-frequency power from a high-frequency power source is applied to a sample stage in the vacuum chamber so that ions in the plasma are made incident upon the sample stage, thereby performing dry etching with respect to a sample on the sample stage. In main etching, a value of (pressure of reactive gas)/(frequency of high-frequency power) is reduced so as to reduce a scattering probability, which is the probability of ions being scattered in collision with neutral particles in a sheath region, thereby increasing the energy of ion fluxes and making the incidence directions of the ion fluxes perpendicular to a surface of the sample stage.
    Type: Grant
    Filed: May 10, 1995
    Date of Patent: February 9, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kenji Harafuji, Masafumi Kubota
  • Patent number: 5753066
    Abstract: An apparatus for generating plasma is disclosed. The apparatus comprises: a plasma chamber; pairs of parallel plate electrodes; and a power supply for applying high-frequency powers on the pairs of electrodes. The frequencies of the high-frequency powers and the phase difference between the high-frequency powers are adjusted so as to cause each of electrons in the plasma to move in a circular path. A dense and highly uniform plasma is generated at a low pressure level, by utilizing the phenomenon of the oscillation, revolution or cycloidal motion of electrons in a high-frequency electric field formed between the parallel plate electrodes. This plasma is suitable for etching in the LSI fabrication process.
    Type: Grant
    Filed: September 12, 1996
    Date of Patent: May 19, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masafumi Kubota, Noboru Nomura, Tokuhiko Tamaki
  • Patent number: 5593539
    Abstract: An apparatus for generating plasma is disclosed. The apparatus comprises: a plasma chamber; pairs of parallel plate electrodes; and a power supply for applying high-frequency powers on the pairs of electrodes. The frequencies of the high-frequency powers and the phase difference between the high-frequency powers are adjusted so as to cause each of electrons in the plasma to move in a circular path. A dense and highly uniform plasma is generated at a low pressure level, by utilizing the phenomenon of the oscillation, revolution or cycloidal motion of electrons in a high-frequency electric field formed between the parallel plate electrodes. This plasma is suitable for etching in the LSI fabrication process.
    Type: Grant
    Filed: April 8, 1994
    Date of Patent: January 14, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masafumi Kubota, Noboru Nomura, Tokuhiko Tamaki
  • Patent number: 5436424
    Abstract: A plasma generating apparatus includes a vacuum chamber having an insulated inner surface, more than two electrodes arranged on the insulated inner surface of the vacuum chamber, a high frequency applying device for applying high frequencies having different phases in order of positions of the electrodes, and a holder on which an object to be processed is placed. In the apparatus, a magnetic field is produced under plural alternating electric fields, so that electrons in a plasma generating portion are rotated to generate high density plasma under a high vacuum when the high frequencies are applied to the electrodes to generate the plasma and a specified process such as etching, CVD, or doping is carried on the object by reaction products generated at the portion.
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: July 25, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ichiro Nakayama, Noboru Nomura, Tokuhiko Tamaki, Mitsuhiro Okuni, Masafumi Kubota
  • Patent number: 5424905
    Abstract: Three electrodes are disposed at lateral sides of a plasma generating chamber of an etching apparatus serving as a plasma generating apparatus. A sample stage is disposed at a lower part of the plasma generating chamber, and an opposite electrode is disposed at an upper part thereof. High frequency electric power having a first frequency is supplied to the sample stage and the opposite electrode. Respectively supplied to the three electrodes 4, 5, 6 are high frequency electric powers which are oscillated by a three-phase magnetron, which have a second frequency different from the first frequency and of which respective phases are successively different by about 120.degree. from one another, thus forming a rotational electric field in the plasma generating chamber.
    Type: Grant
    Filed: March 30, 1993
    Date of Patent: June 13, 1995
    Assignee: Matsushita Electric Company, Ltd.
    Inventors: Noboru Nomura, Kenji Harafuji, Masafumi Kubota, Tokuhiko Tamaki, Mitsuhiro Ohkuni, Ichiro Nakayama
  • Patent number: 5404079
    Abstract: On the inner surface of a chamber are circumferentially disposed three lateral electrodes at regular intervals. To the lateral electrodes are applied three high-frequency electric powers of 50 MHz, each differing in phase by approximately 120.degree.. On the bottom of the chamber is placed a sample stage serving as a second electrode, around which is provided a ring-shaped earth electrode. To the sample stage is applied high-frequency electric power of 13.56 MHz. The distance between each of the three lateral electrodes and the earth electrode is longer than the distance between the sample stage and the earth electrode.
    Type: Grant
    Filed: July 27, 1993
    Date of Patent: April 4, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsuhiro Ohkuni, Masafumi Kubota, Noboru Nomura, Ichiro Nakayama, Tokuhiko Tamaki
  • Patent number: 5345145
    Abstract: A plasma generating method comprises: a first step of disposing a plurality of lateral electrodes at lateral sides of a plasma generating part in a vacuum chamber; a second step of respectively applying, to the lateral electrodes, high frequency electric powers of which frequencies are the same as one another and of which phases are different from one another, thereby to excite, in the plasma generating part, a high frequency rotating electric field to cause electrons under translational motions in the plasma generating part to present oscillating or rotating motions; and a third step of applying, to the plasma generating part, a magnetic field substantially at a right angle to the working plane of the high frequency rotating electric field, thereby to convert the translational movement of the electrons in the plasma generating part into revolving motions under oscillating or rotating motions by which the electrons revolve in the plasma generating part.
    Type: Grant
    Filed: March 30, 1993
    Date of Patent: September 6, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kenji Harafuji, Mitsuhiro Ohkuni, Tokuhiko Tamaki, Masafumi Kubota, Noboru Nomura
  • Patent number: 5332880
    Abstract: At lateral sides of a plasma generating part under a vacuum, first to fourth lateral electrodes are so disposed as to surround the plasma generating part. High frequency electric power is supplied to the first lateral electrode from a first high frequency power supply, high frequency electric power is supplied to the second lateral electrode from the first high frequency power supply through a first delay circuit, high frequency electric power is supplied to the third lateral electrode from the first high frequency power supply through the first delay circuit and through a second delay circuit, and high frequency electric power is supplied to the fourth lateral electrode from the first high frequency power supply through the first and second delay circuits and through a third delay circuit.
    Type: Grant
    Filed: March 30, 1993
    Date of Patent: July 26, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masafumi Kubota, Kenji Harafuji, Tokuhiko Tamaki, Mitsuhiro Ohkuni, Noboru Nomura, Ichiro Nakayama
  • Patent number: 5330606
    Abstract: An apparatus for generating plasma is disclosed. The apparatus comprises: a plasma chamber; pairs of parallel plate electrodes; and a power supply for applying high-frequency powers on the pairs of electrodes. The frequencies of the high-frequency powers and the phase difference between the high-frequency powers are adjusted so as to cause each of electrons in the plasma to move in a circular path. A dense and highly uniform plasma is generated at a low pressure level, by utilizing the phenomenon of the oscillation, revolution or cycloidal motion of electrons in a high-frequency electric field formed between the parallel plate electrodes. This plasma is suitable for etching in the LSI fabrication process.
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: July 19, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masafumi Kubota, Noboru Nomura, Tokuhiko Tamaki
  • Patent number: 5324388
    Abstract: Magnetic coils are provided around a plasma generation chamber. To the plasma generation chamber is supplied a microwave which is generated by a microwave generator. Electron cyclotron resonance is caused by the interaction between a magnetic field produced by the magnetic coils and the microwave generated by the microwave generator, so as to accelerate electrons in the plasma generation chamber. The electrons thus accelerated generates a plasma. A reaction chamber is provided underneath the plasma generation chamber. The plasma generated in the plasma generation chamber is introduced to the reaction chamber to be used for etching a material on a sample stage. A reflex klystron is used as the microwave generator. By changing the cavity length of the reflex klystron, the resonance frequency of the cavity resonator is varied, thus modulating the frequency of the microwave supplied to the plasma generation chamber by the microwave generator.
    Type: Grant
    Filed: June 11, 1993
    Date of Patent: June 28, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Atsuhiro Yamano, Masafumi Kubota, Kenji Harafuji
  • Patent number: 5312776
    Abstract: According to the method of preventing the corrosion of metallic wirings of the present invention, aluminium alloy wirings are formed on the surface of a substrate with the use of photoresists, and the photoresists are then removed. Thereafter, HMDS (hexamethyl disilazine) serving as a surface-active agent or its derivative is supplied to the aluminium alloy wirings to form hydrophobic molecular layers on the lateral walls of the aluminium alloy wirings.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: May 17, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tomoyasu Murakami, Michinari Yamanaka, Kousaku Yano, Masayuki Endo, Noboru Nomura, Staoshi Ueda, Naoto Matsuo, Hiroshi Imai, Masafumi Kubota
  • Patent number: 5259922
    Abstract: A dry etching method of a substrate or layer of a semiconductor or other material which includes the steps of providing a metallic chamber having an anode and a cathode which are spaced from each other and mounting the substrate or layer to be etched on the cathode, and applying a potential from a RF power supply to the cathode so that a plasma is generated between the anode and the cathode to produce a bulk region and sheath regions between the cathode and the anode. The frequency of the RF power supply is set at a level higher than 13.56 MHz under which the substrate or layer is subjected to etching with the ions. A polysilicon, SiN or Al alloy layer can be efficiently etched with a Cl-based etching gas.
    Type: Grant
    Filed: August 14, 1991
    Date of Patent: November 9, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Atsuhiro Yamano, Tokuhiko Tamaki, Masafumi Kubota, Kenji Harafuji, Noboru Nomura