Patents by Inventor Takayuki Aoyama

Takayuki Aoyama 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: 10985021
    Abstract: A gallium nitride (GaN) substrate is injected with magnesium as a p-type dopant. The GaN substrate undergoes preheating through irradiation with light from halogen lamps in an atmosphere containing nitrogen and hydrogen, and further undergoes heating to a high temperature for a super-short time through irradiation with flashes of light from flash lamps. Heating the GaN substrate in the atmosphere containing nitrogen and hydrogen complements removed nitrogen, thus preventing nitrogen shortage. Such a heating process also enables heat treatment while supplying hydrogen to the GaN substrate. The heating process further enables crystal defects in the GaN substrate to be recovered. With these effects, the p-type dopant injected into the GaN substrate is activated with high efficiency.
    Type: Grant
    Filed: July 23, 2019
    Date of Patent: April 20, 2021
    Assignee: SCREEN HOLDINGS CO., LTD.
    Inventors: Hideaki Tanimura, Takahiro Yamada, Shinichi Kato, Takayuki Aoyama
  • Patent number: 10978319
    Abstract: Over a front surface of a silicon semiconductor wafer is deposited a high dielectric constant film with a silicon oxide film, serving as an interface layer, provided between the semiconductor wafer and the high dielectric constant film. After a chamber houses the semiconductor wafer, a chamber's pressure is reduced to be lower than atmospheric pressure. Subsequently, a gaseous mixture of ammonia and nitrogen gas is supplied into the chamber to return the pressure to ordinary pressure, and the front surface is irradiated with a flash light, thereby performing post deposition annealing (PDA) on the high dielectric constant film. Since the pressure is reduced once to be lower than atmospheric pressure and then returned to ordinary pressure, a chamber's oxygen concentration is lowered remarkably during the PDA. This restricts an increase in thickness of the silicon oxide film underlying the high dielectric constant film by oxygen taken in during the PDA.
    Type: Grant
    Filed: September 27, 2018
    Date of Patent: April 13, 2021
    Assignee: SCREEN Holdings Co., Ltd.
    Inventors: Takayuki Aoyama, Hikaru Kawarazaki, Masashi Furukawa, Shinichi Kato, Kazuhiko Fuse, Hideaki Tanimura
  • Patent number: 10886132
    Abstract: A semiconductor wafer serving as a treatment target has a stack structure in which a high-dielectric-constant gate insulating film is formed on a silicon base material with an interface layer film of silicon dioxide sandwiched therebetween, and a metal gate electrode containing fluorine is further formed thereon. A heat treatment apparatus radiates flash light from a flash lamp to the semiconductor wafer in an atmosphere containing hydrogen to carry out heating treatment for an extremely short period of time of 100 milliseconds or less. As a result, diffusion of nitrogen contained in the metal gate electrode is inhibited, at the same time, only the fluorine is diffused from the high-dielectric-constant gate insulating film to an interface between the interface layer film and the silicon base material to reduce an interface state, and reliability of the gate stack structure can be improved.
    Type: Grant
    Filed: July 1, 2019
    Date of Patent: January 5, 2021
    Assignee: SCREEN HOLDINGS CO., LTD.
    Inventor: Takayuki Aoyama
  • Patent number: 10790171
    Abstract: Over a front surface of a silicon semiconductor wafer is deposited a high dielectric constant film with a silicon oxide film, serving as an interface layer, provided between the semiconductor wafer and the high dielectric constant film. After a chamber houses the semiconductor wafer, a chamber's pressure is reduced to be lower than atmospheric pressure. Subsequently, a gaseous mixture of ammonia and nitrogen gas is supplied into the chamber to return the pressure to ordinary pressure, and the front surface is irradiated with a flash light, thereby performing post deposition annealing (PDA) on the high dielectric constant film. Since the pressure is reduced once to be lower than atmospheric pressure and then returned to ordinary pressure, a chamber's oxygen concentration is lowered remarkably during the PDA. This restricts an increase in thickness of the silicon oxide film underlying the high dielectric constant film by oxygen taken in during the PDA.
    Type: Grant
    Filed: June 25, 2019
    Date of Patent: September 29, 2020
    Assignee: SCREEN Holdings Co., Ltd.
    Inventors: Takayuki Aoyama, Hikaru Kawarazaki, Masashi Furukawa, Shinichi Kato, Kazuhiko Fuse, Hideaki Tanimura
  • Publication number: 20200266084
    Abstract: A semiconductor wafer transport mode of a heat treatment apparatus is switchable between two modes of a “high throughput mode” and a “low oxygen concentration mode” as appropriate. In the “low oxygen concentration mode”, a first cooling chamber is used only as a path for transferring the semiconductor wafer, and a second cooling chamber is used only as a dedicated cooling unit for cooling the semiconductor wafer subjected to flash heating. On the other hand, in the “high throughput mode”, both of the first cooling chamber and the second cooling chamber are used as paths for transferring the semiconductor wafer, and as the cooling units, too.
    Type: Application
    Filed: April 22, 2020
    Publication date: August 20, 2020
    Inventors: Takayuki AOYAMA, Shinichi IKEDA, Akitsugu UEDA
  • Publication number: 20200196389
    Abstract: A carrier containing a plurality of semiconductor wafers in a lot is transported into a heat treatment apparatus. Thereafter, a recipe specifying treatment procedures and treatment conditions is set for each of the semiconductor wafers. Next, a reflectance of each of the semiconductor wafers stored in the carrier is measured. Based on the set recipe and the measured reflectance of each semiconductor wafer, a predicted attainable temperature of each semiconductor wafer at the time of flash heating treatment is calculated, and the calculated predicted attainable temperature is displayed. This allows the setting of the treatment conditions with reference to the displayed predicted attainable temperature, to thereby easily achieve the setting of the heat treatment conditions.
    Type: Application
    Filed: December 2, 2019
    Publication date: June 18, 2020
    Inventors: Tomohiro UENO, Takayuki AOYAMA, Mao OMORI, Takahiro KITAZAWA, Katsuichi AKIYOSHI
  • Patent number: 10643850
    Abstract: A PSG film, which is a silicon dioxide thin film containing phosphorus as a dopant, is formed on the surface of a semiconductor wafer. The semiconductor wafer having the PSG film formed thereon is kept at a predetermined heating temperature by light radiation from halogen lamps in the atmosphere containing hydrogen for 1 second or longer, so that the dopant is diffused from the PSG film into the surface of the semiconductor wafer. In addition, the flashing light is radiated to the semiconductor wafer for the radiation time shorter than 1 second to heat the surface of the semiconductor wafer to the target temperature so as to activate the dopant. When the PSG film is heated in the atmosphere containing hydrogen, a diffusion coefficient of the dopant contained in the PSG film becomes high; therefore, the dopant can be efficiently diffused from the PSG film into the semiconductor wafer.
    Type: Grant
    Filed: November 16, 2017
    Date of Patent: May 5, 2020
    Assignee: SCREEN HOLDINGS CO., LTD.
    Inventors: Hideaki Tanimura, Takayuki Aoyama, Kazuhiko Fuse, Takahiro Yamada
  • Patent number: 10578192
    Abstract: A degree of freedom of a hypoid gear is improved. An instantaneous axis in a relative rotation of a gear axis and a pinion axis, a line of centers, an intersection between the instantaneous axis and the line of centers, and an inclination angle of the instantaneous axis with respect to the rotation axis of the gear are calculated based on a shaft angle, an offset, and a gear ratio of a hypoid gear. Based on these variables, base coordinate systems are determined, and the specifications are calculated using these coordinate systems. For the spiral angles, pitch cone angles, and reference circle radii of the gear and pinion, one of the values for the gear and the pinion is set and a design reference point is calculated. Based on the design reference point and a contact normal of the gear, specifications are calculated. The pitch cone angle of the gear or the pinion can be freely selected.
    Type: Grant
    Filed: May 15, 2018
    Date of Patent: March 3, 2020
    Assignees: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Takayuki Aoyama, Mizuho Inagaki, Kiyokazu Sunami, Sho Honda, Yoshikatsu Shibata, Hiromi Miyamura
  • Patent number: 10580667
    Abstract: A heat treatment apparatus is provided with two cool chambers, that is, a first cool chamber and a second cool chamber. A semiconductor wafer before treatment is alternately carried into the first cool chamber or the second cool chamber and then transported to a heat treatment part by a transport robot after a nitrogen purge is performed. The semiconductor wafer after being heat-treated in the heat treatment part is alternately transported to the first cool chamber or the second cool chamber to be cooled. A sufficient cooling time is secured for the independent semiconductor wafer, and a reduction in throughput as the whole heat treatment apparatus can be suppressed.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: March 3, 2020
    Assignee: SCREEN Holdings Co., Ltd.
    Inventors: Takayuki Aoyama, Yasuaki Kondo, Shinji Miyawaki, Shinichi Kato, Kazuhiko Fuse, Hideaki Tanimura, Akitsugu Ueda, Hikaru Kawarazaki, Masashi Furukawa
  • Publication number: 20200066532
    Abstract: A gallium nitride (GaN) substrate is injected with magnesium as a p-type dopant. The GaN substrate undergoes preheating through irradiation with light from halogen lamps in an atmosphere containing nitrogen and hydrogen, and further undergoes heating to a high temperature for a super-short time through irradiation with flashes of light from flash lamps. Heating the GaN substrate in the atmosphere containing nitrogen and hydrogen complements removed nitrogen, thus preventing nitrogen shortage. Such a heating process also enables heat treatment while supplying hydrogen to the GaN substrate. The heating process further enables crystal defects in the GaN substrate to be recovered. With these effects, the p-type dopant injected into the GaN substrate is activated with high efficiency.
    Type: Application
    Filed: July 23, 2019
    Publication date: February 27, 2020
    Inventors: Hideaki TANIMURA, Takahiro YAMADA, Shinichi KATO, Takayuki AOYAMA
  • Publication number: 20190371632
    Abstract: From a stage of preheating by a halogen lamp to irradiation with a flash by a flash lamp, a radiation thermometer is used for measuring the temperature of a back surface of a semiconductor wafer. A increased temperature ?T is determined by which the back surface of the semiconductor wafer is increased in temperature from the preheating temperature by irradiation with a flash. The specific heat of the semiconductor wafer has a known value. Further, the increased temperature ?T is proportionate to the magnitude of energy applied to a front surface of the semiconductor wafer by irradiation with a flash. Thus, a front surface attained temperature of the semiconductor wafer can be determined using the increased temperature ?T of the back surface of the semiconductor wafer during irradiation with a flash.
    Type: Application
    Filed: August 19, 2019
    Publication date: December 5, 2019
    Inventor: Takayuki AOYAMA
  • Publication number: 20190326121
    Abstract: A semiconductor wafer serving as a treatment target has a stack structure in which a high-dielectric-constant gate insulating film is formed on a silicon base material with an interface layer film of silicon dioxide sandwiched therebetween, and a metal gate electrode containing fluorine is further formed thereon. A heat treatment apparatus radiates flash light from a flash lamp to the semiconductor wafer in an atmosphere containing hydrogen to carry out heating treatment for an extremely short period of time of 100 milliseconds or less. As a result, diffusion of nitrogen contained in the metal gate electrode is inhibited, at the same time, only the fluorine is diffused from the high-dielectric-constant gate insulating film to an interface between the interface layer film and the silicon base material to reduce an interface state, and reliability of the gate stack structure can be improved.
    Type: Application
    Filed: July 1, 2019
    Publication date: October 24, 2019
    Inventor: Takayuki AOYAMA
  • Patent number: 10453715
    Abstract: From a stage of preheating by a halogen lamp to irradiation with a flash by a flash lamp, a radiation thermometer is used for measuring the temperature of a back surface of a semiconductor wafer. A increased temperature ?T is determined by which the back surface of the semiconductor wafer is increased in temperature from the preheating temperature by irradiation with a flash. The specific heat of the semiconductor wafer has a known value. Further, the increased temperature ?T is proportionate to the magnitude of energy applied to a front surface of the semiconductor wafer by irradiation with a flash. Thus, a front surface attained temperature of the semiconductor wafer can be determined using the increased temperature ?T of the back surface of the semiconductor wafer during irradiation with a flash.
    Type: Grant
    Filed: July 8, 2016
    Date of Patent: October 22, 2019
    Assignee: SCREEN Holdings Co., Ltd.
    Inventor: Takayuki Aoyama
  • Patent number: 10446397
    Abstract: When an insulated gate bipolar transistor is incorporated in a drive circuit of a flash lamp, so that a light emission pattern of the flash lamp is freely defined, a temperature change pattern of a surface of a semiconductor wafer that receives the emission of flash light can be adjusted. The length of diffusion of impurities can be controlled by rising a surface temperature of the semiconductor wafer from a preheating temperature to a diffusion temperature through emission of flash light and maintaining the surface temperature at the diffusion temperature for a time period not shorter than 1 millisecond and not longer than 10 milliseconds. Subsequently, the impurities can be activated by rising the surface temperature of the semiconductor wafer from the diffusion temperature to an activation temperature.
    Type: Grant
    Filed: October 19, 2016
    Date of Patent: October 15, 2019
    Assignee: SCREEN Holdings Co., Ltd.
    Inventors: Takayuki Aoyama, Hikaru Kawarazaki
  • Publication number: 20190311924
    Abstract: Over a front surface of a silicon semiconductor wafer is deposited a high dielectric constant film with a silicon oxide film, serving as an interface layer, provided between the semiconductor wafer and the high dielectric constant film. After a chamber houses the semiconductor wafer, a chamber's pressure is reduced to be lower than atmospheric pressure. Subsequently, a gaseous mixture of ammonia and nitrogen gas is supplied into the chamber to return the pressure to ordinary pressure, and the front surface is irradiated with a flash light, thereby performing post deposition annealing (PDA) on the high dielectric constant film. Since the pressure is reduced once to be lower than atmospheric pressure and then returned to ordinary pressure, a chamber's oxygen concentration is lowered remarkably during the PDA. This restricts an increase in thickness of the silicon oxide film underlying the high dielectric constant film by oxygen taken in during the PDA.
    Type: Application
    Filed: June 25, 2019
    Publication date: October 10, 2019
    Inventors: Takayuki AOYAMA, Hikaru KAWARAZAKI, Masashi FURUKAWA, Shinichi KATO, Kazuhiko FUSE, Hideaki TANIMURA
  • Patent number: 10424483
    Abstract: A metal film is deposited on a front surface of a semiconductor wafer of silicon. After the semiconductor wafer is received in a chamber, the pressure in the chamber is reduced to a pressure lower than atmospheric pressure. Thereafter, nitrogen gas is supplied into the chamber to return the pressure in the chamber to ordinary pressure, and the front surface of the semiconductor wafer is irradiated with a flash of light, so that a silicide that is a compound of the metal film and silicon is formed. The oxygen concentration in the chamber is significantly lowered during the formation of the silicide because the pressure in the chamber is reduced once to the pressure lower than atmospheric pressure and then returned to the ordinary pressure. This suppresses the increase in resistance of the silicide resulting from the entry of oxygen in the atmosphere in the chamber into defects near the interface between the metal film and a base material.
    Type: Grant
    Filed: December 3, 2018
    Date of Patent: September 24, 2019
    Assignee: SCREEN Holdings Co., Ltd.
    Inventors: Takayuki Aoyama, Hikaru Kawarazaki, Masashi Furukawa, Kazuhiko Fuse, Hideaki Tanimura, Shinichi Kato
  • Publication number: 20190267262
    Abstract: When pressure in a chamber is brought to atmospheric pressure and the chamber is filled with an inert gas atmosphere, the atmosphere in the chamber is sucked into an oxygen concentration analyzer through a sampling line such that oxygen concentration in the chamber is measured by the oxygen concentration analyzer. When the pressure in the chamber is reduced to less than atmospheric pressure, nitrogen gas is supplied to the oxygen concentration analyzer through an inert gas supply line simultaneously with suspending the measurement of oxygen concentration in the chamber. Even when the measurement of oxygen concentration in the chamber is suspended, reverse flow to the oxygen concentration analyzer from a gas exhaust pipe can be prevented, and the oxygen concentration analyzer can be prevented from being exposed to exhaust from the chamber. The configuration results in maintaining measurement accuracy of the oxygen concentration analyzer in a low oxygen concentration range.
    Type: Application
    Filed: January 24, 2019
    Publication date: August 29, 2019
    Inventors: Takayuki AOYAMA, Akitsugu UEDA, Mao OMORI, Kazunori AMAGO
  • Publication number: 20190164789
    Abstract: A semiconductor wafer to be treated is heated at a first preheating temperature ranging from 100 to 200° C. while a pressure in a chamber housing the semiconductor wafer is reduced to a pressure lower than an atmospheric pressure. After the semiconductor wafer is preheated to increase the temperature into a second preheating temperature ranging from 500 to 700° C. while the pressure in the chamber is restored to a pressure higher than the reduced pressure, a flash lamp emits a flashlight to a surface of the semiconductor wafer. Heating the semiconductor wafer at the first preheating temperature that is a relatively low temperature enables, for example, the moisture absorbed on the surface of the semiconductor wafer in trace amounts to be desorbed from the surface, and also enables the flash heating treatment to be performed with oxygen derived from such absorption removed as much as possible.
    Type: Application
    Filed: April 4, 2017
    Publication date: May 30, 2019
    Inventors: Takayuki AOYAMA, Shinichi KATO, Kazuhiko FUSE, Hikaru KAWARAZAKI, Masashi FURUKAWA, Hideaki TANIMURA, Akitsugu UEDA
  • Publication number: 20190109007
    Abstract: A metal film is deposited on a front surface of a semiconductor wafer of silicon. After the semiconductor wafer is received in a chamber, the pressure in the chamber is reduced to a pressure lower than atmospheric pressure. Thereafter, nitrogen gas is supplied into the chamber to return the pressure in the chamber to ordinary pressure, and the front surface of the semiconductor wafer is irradiated with a flash of light, so that a silicide that is a compound of the metal film and silicon is formed. The oxygen concentration in the chamber is significantly lowered during the formation of the silicide because the pressure in the chamber is reduced once to the pressure lower than atmospheric pressure and then returned to the ordinary pressure. This suppresses the increase in resistance of the silicide resulting from the entry of oxygen in the atmosphere in the chamber into defects near the interface between the metal film and a base material.
    Type: Application
    Filed: December 3, 2018
    Publication date: April 11, 2019
    Inventors: Takayuki AOYAMA, Hikaru KAWARAZAKI, Masashi FURUKAWA, Kazuhiko FUSE, Hideaki TANIMURA, Shinichi KATO
  • Publication number: 20190027385
    Abstract: Over a front surface of a silicon semiconductor wafer is deposited a high dielectric constant film with a silicon oxide film, serving as an interface layer, provided between the semiconductor wafer and the high dielectric constant film. After a chamber houses the semiconductor wafer, a chamber's pressure is reduced to be lower than atmospheric pressure. Subsequently, a gaseous mixture of ammonia and nitrogen gas is supplied into the chamber to return the pressure to ordinary pressure, and the front surface is irradiated with a flash light, thereby performing post deposition annealing (PDA) on the high dielectric constant film. Since the pressure is reduced once to be lower than atmospheric pressure and then returned to ordinary pressure, a chamber's oxygen concentration is lowered remarkably during the PDA. This restricts an increase in thickness of the silicon oxide film underlying the high dielectric constant film by oxygen taken in during the PDA.
    Type: Application
    Filed: September 27, 2018
    Publication date: January 24, 2019
    Inventors: Takayuki AOYAMA, Hikaru KAWARAZAKI, Masashi FURUKAWA, Shinichi KATO, Kazuhiko FUSE, Hideaki TANIMURA