Patents by Inventor Takaoki Sasaki

Takaoki Sasaki 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: 9461138
    Abstract: A non-volatile semiconductor memory free from adverse effects due to process charge is provided. The non-volatile semiconductor memory includes: a silicon substrate; a first silicon oxide film; a second silicon oxide film; a first silicon nitride film; and a second silicon nitride film, wherein the first silicon oxide film is layered on the silicon substrate, the first silicon nitride film is layered on the first silicon oxide film, the second silicon oxide film is layered on the first silicon nitride film, and the second silicon nitride film is layered to have a first part that is in contact with the first silicon nitride film and a second part that is in contact with the silicon substrate.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: October 4, 2016
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Yohei Fukumoto, Takaoki Sasaki
  • Publication number: 20150008500
    Abstract: A non-volatile semiconductor memory free from adverse effects due to process charge is provided. The non-volatile semiconductor memory includes: a silicon substrate; a first silicon oxide film; a second silicon oxide film; a first silicon nitride film; and a second silicon nitride film, wherein the first silicon oxide film is layered on the silicon substrate, the first silicon nitride film is layered on the first silicon oxide film, the second silicon oxide film is layered on the first silicon nitride film, and the second silicon nitride film is layered to have a first part that is in contact with the first silicon nitride film and a second part that is in contact with the silicon substrate.
    Type: Application
    Filed: February 22, 2013
    Publication date: January 8, 2015
    Inventors: Yohei Fukumoto, Takaoki Sasaki
  • Patent number: 7855125
    Abstract: A method for manufacturing a semiconductor device includes: forming a groove in a semiconductor substrate and embedding an element isolation film made of a silicon oxide film in the groove; forming a silicon nitride film on the element isolation film; forming an oxidized silicon nitride film on the surface of the element isolation film through thermal treatment of the element isolation film and the silicon nitride film; and removing the silicon nitride film.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: December 21, 2010
    Assignee: Seiko Epson Corporation
    Inventor: Takaoki Sasaki
  • Patent number: 7541246
    Abstract: A gate insulating film and a gate electrode are formed on a silicon substrate. The gate insulating film contains at least hafnium, oxygen, fluorine, and nitrogen. The fluorine concentration is high in the vicinity of an interface with the silicon substrate and progressively decreases with decreasing distance from the gate electrode. The nitrogen concentration is high in the vicinity of an interface with the gate electrode and progressively decreases with decreasing distance from the silicon substrate. The fluorine concentration in the vicinity of the interface with the silicon substrate is preferably 1×1019 cm?3 or more. The nitrogen concentration in the vicinity of the interface with the gate electrode is preferably 1×1020 cm?3 or more.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: June 2, 2009
    Assignee: Fujitsu Limited
    Inventors: Yasuyuki Tamura, Takaoki Sasaki
  • Patent number: 7512801
    Abstract: The authentication system has a signing station and a certifying station. The signing station divides the data to be transmitted into a plurality of data, a hash unit creates a plurality of authenticators by applying a different one-way function to each of the data. In the certifying station, a separating unit divides the data into a plurality of data, a hash unit creates a plurality of authenticators by applying a different one-way function to each data, and a comparing unit compares the authenticators prepared anew with the authenticators separated from the received data and checks the authentication of the data from the comparison.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: March 31, 2009
    Assignee: Fujitsu Limited
    Inventors: Ryota Akiyama, Seigo Kotani, Takayuki Hasebe, Takaoki Sasaki
  • Patent number: 7487366
    Abstract: A data protection program is able to effectively restrict an unauthorized access to a resource to be protected even when the resource to be protected is in a state legitimately accessed by a user. The identification information about a program capable of accessing the resource to be protected is registered in an access permission management table. If an access request to access the resource to be protected is subsequently received, then identification information about a request source program which has outputted the access request is acquired. Then, it is determined whether access to the resource to be protected is permitted or not based on whether the identification information about the request source program has been registered in the access permission management table or not. If access to the resource to be protected is permitted, data in the resource to be protected is processed in response to the access request.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: February 3, 2009
    Assignee: Fujitsu Limited
    Inventors: Yuu Umebayashi, Etsu Den, Yusuke Yamanaka, Takaoki Sasaki
  • Publication number: 20080224234
    Abstract: A method for manufacturing a semiconductor device includes: forming a groove in a semiconductor substrate and embedding an element isolation film made of a silicon oxide film in the groove; forming a silicon nitride film on the element isolation film; forming an oxidized silicon nitride film on the surface of the element isolation film through thermal treatment of the element isolation film and the silicon nitride film; and removing the silicon nitride film.
    Type: Application
    Filed: February 27, 2008
    Publication date: September 18, 2008
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Takaoki SASAKI
  • Patent number: 7306985
    Abstract: A gate insulating film having an insulating film that contains at least nitrogen is formed on a substrate, and the gate insulating film is subjected to heat treatment for about 500 milliseconds or less using a flash lamp. Thereafter, a gate electrode is formed on the gate insulating film. Specifically, for example, a laminated film of SiO2 film and an SixN(1-x) film, a laminated film of an SiO2 film, HfSiO film, and an SixN(1-x) film, or the like, is formed in forming the gate insulating film.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: December 11, 2007
    Assignee: Seiko Epson Corporation
    Inventors: Takaoki Sasaki, Takeshi Hoshi
  • Publication number: 20070064946
    Abstract: A computer-readable recording medium recording a character code encryption program capable of encrypting character codes without changing the data length. When plaintext is input, a plaintext encoder converts character codes included in the plaintext to corresponding numerical values. Then, an encryptor successively acquires the numerical values of the individual character codes, obtained by the plaintext encoder, to encrypt the first numerical value into an encrypted value with an identical number of bits, by using an initial value set in a register, and then to encrypt the rest of the input numerical values by alternately repeating updating of the register value by using at least part of the encrypted value and encryption of the numerical value by using the updated register value. A character code generator converts the individual encrypted values obtained by the encryptor to corresponding character codes, thereby generating ciphertext.
    Type: Application
    Filed: December 1, 2005
    Publication date: March 22, 2007
    Applicant: FUJITSU BROAD SOLUTION & CONSULTING INC.
    Inventors: Shigeyuki Ohkubo, Ryota Akiyama, Toshihiro Suzuki, Yuji Miyamoto, Takaoki Sasaki
  • Publication number: 20060273412
    Abstract: A gate insulating film and a gate electrode are formed on a silicon substrate. The gate insulating film contains at least hafnium, oxygen, fluorine, and nitrogen. The fluorine concentration is high in the vicinity of an interface with the silicon substrate and progressively decreases with decreasing distance from the gate electrode. The nitrogen concentration is high in the vicinity of an interface with the gate electrode and progressively decreases with decreasing distance from the silicon substrate. The fluorine concentration in the vicinity of the interface with the silicon substrate is preferably 1×109 cm?3 or more. The nitrogen concentration in the vicinity of the interface with the gate electrode is preferably 1×1020 cm?3 or more.
    Type: Application
    Filed: August 11, 2006
    Publication date: December 7, 2006
    Applicant: FUJITSU LIMITED
    Inventors: Yasuyuki TAMURA, Takaoki SASAKI
  • Patent number: 7138692
    Abstract: A gate insulating film and a gate electrode are formed on a silicon substrate. The gate insulating film contains at least hafnium, oxygen, fluorine, and nitrogen. The fluorine concentration is high in the vicinity of an interface with the silicon substrate and progressively decreases with decreasing distance from the gate electrode. The nitrogen concentration is high in the vicinity of an interface with the gate electrode and progressively decreases with decreasing distance from the silicon substrate. The fluorine concentration in the vicinity of the interface with the silicon substrate is preferably 1×1019 cm?3 or more. The nitrogen concentration in the vicinity of the interface with the gate electrode is preferably 1×1020 cm?3 or more.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: November 21, 2006
    Assignee: Fujitsu Limited
    Inventors: Yasuyuki Tamura, Takaoki Sasaki
  • Publication number: 20060081939
    Abstract: A semiconductor device having a metal insulator semiconductor field effect transistor (MISFET) with increased electron mobility and enhanced hole mobility is disclosed. In this semiconductor device, a p-type well layer and an n-type well layer are formed in a surface portion of a silicon substrate. A nitrogen-nondoped n-channel interface layer and a nitrogen-free n-channel high dielectric constant gate insulation film plus an n-channel gate electrode are formed in an n-channel MISFET as partitioned by an element isolation region. And, n-type source/drain diffusion layers are provided. In a p-channel MISFET, a nitrogen-doped p-channel interface layer, a nitrogen-added p-channel high dielectric gate insulation film and a p-channel gate electrode are formed along with p-channel source/drain diffusion layers as provided therein. A method of fabricating this semiconductor device is also disclosed.
    Type: Application
    Filed: September 9, 2005
    Publication date: April 20, 2006
    Inventors: Yasushi Akasaka, Kazuhiro Miyagawa, Takaoki Sasaki
  • Patent number: 7013392
    Abstract: A file processing unit comprises a first signature information producing unit that produces first signature information in accordance with a predetermined rule utilizing the data of a file designated by a file close request issued in an application used in a computer system, and a signature information storage control unit that stores the first signature information, correlated with the file designated by the file close request, in a storage unit.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: March 14, 2006
    Assignee: Fujitsu Limited
    Inventors: Takaoki Sasaki, Takeshi Hatano, Ryota Akiyama, Seigo Kotani, Takayuki Hasebe
  • Patent number: 7010127
    Abstract: A cryptographic communication method is provided in which a cryptographic communication is performed by an easy operation even if both enciphered data and unenciphered data are mixed to be handled. In the transmission side, a communication key is used for enciphering data to be transmitted, and in the reception side the same communication key as in the transmission side is used for decoding received data. In the transmission side, an individual key that is different from the communication key is used for enciphering the data to be transmitted, the enciphered data are decoded by using the individual key first, and then the decoded data are enciphered by using the communication key so that the enciphered file can be transmitted.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: March 7, 2006
    Assignee: Fujitsu Limited
    Inventors: Seigo Kotani, Takaoki Sasaki, Yusuke Yamanaka, Takayuki Hasebe, Ryota Akiyama
  • Patent number: 7000114
    Abstract: In a signature creating apparatus, a clock generates a time stamp and in which time can be set only by a computer installed in a certificate authority center. Further, connecting sections connects an apparatus ID for specifying an apparatus and the time stamp and personal identification information for identifying an implementor to a plain-text so as to create data for the signature. A signature creating circuit encrypts the data for the signature using a signature creating key or the like and generates the signature. A connecting section connects the signature to the data for the signature and transmits the data as data after signature.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: February 14, 2006
    Assignee: Fujitsu Limited
    Inventors: Takayuki Hasebe, Seigo Kotani, Ryota Akiyama, Takaoki Sasaki
  • Publication number: 20050274948
    Abstract: A gate insulating film and a gate electrode are formed on a silicon substrate. The gate insulating film contains at least hafnium, oxygen, fluorine, and nitrogen. The fluorine concentration is high in the vicinity of an interface with the silicon substrate and progressively decreases with decreasing distance from the gate electrode. The nitrogen concentration is high in the vicinity of an interface with the gate electrode and progressively decreases with decreasing distance from the silicon substrate. The fluorine concentration in the vicinity of the interface with the silicon substrate is preferably 1×1019 cm?3 or more. The nitrogen concentration in the vicinity of the interface with the gate electrode is preferably 1×1020 cm?3 or more.
    Type: Application
    Filed: December 17, 2004
    Publication date: December 15, 2005
    Applicant: Semiconductor Leading Edge Technologies, Inc.
    Inventors: Yasuyuki Tamura, Takaoki Sasaki
  • Publication number: 20050216466
    Abstract: Based on user permission information read from a write-protected portable medium, it is determined whether an application is permitted to use a resource. If the application is permitted to use the resource, the write protection of the portable medium is released, usage log information is written into the medium.
    Type: Application
    Filed: July 21, 2004
    Publication date: September 29, 2005
    Applicant: Fujitsu Limited
    Inventors: Yuji Miyamoto, Yusuke Yamanaka, Yue Tian, Takaoki Sasaki, Mikito Hikita
  • Publication number: 20050086447
    Abstract: A program to block information leaks via access control with a simple process. When a user logs in, a security apparatus retrieves access right information for this user from an access right information file and creates a use restriction table for the user. The use restriction table indicates use restrictions on each resource. The apparatus watches and acquires an access request for a resource from an operating system before operating the resource. When acquiring an access request, the apparatus extracts use restriction information on the resource specified by the access request from the use restriction table and restricts the use of the resource according to the use restriction information.
    Type: Application
    Filed: March 5, 2004
    Publication date: April 21, 2005
    Applicant: Fujitsu Limited
    Inventors: Yuji Miyamoto, Yusuke Yamanaka, Yue Tian, Takaoki Sasaki
  • Publication number: 20050055313
    Abstract: One of a plurality of users purchases a PC card in which software is included from a distributor of communication software or a seller of PC cards. This purchaser informs a non-purchaser through a safe channel such as off-line of a key for encryption, a URL of the site from which to download the software and a retrieval induction code. The non-purchaser accesses the distributor of communication software, etc., via a network using the URL, key and retrieval induction code, downloads the software corresponding to the software that the purchaser owns, and executes cipher communications or a competition game with the purchaser. The distributor of software or the seller of PC cards pays the purchaser who satisfies certain conditions based upon the contents registered in the user management database.
    Type: Application
    Filed: March 7, 2001
    Publication date: March 10, 2005
    Inventors: Takaoki Sasaki, Ryota Akiyama, Ryohei Kanou
  • Publication number: 20050045967
    Abstract: A gate insulating film having an insulating film that contains at least nitrogen is formed on a substrate, and the gate insulating film is subjected to heat treatment for about 500 milliseconds or less using a flash lamp. Thereafter, a gate electrode is formed on the gate insulating film. Specifically, for example, a laminated film of SiO2 and SixN(1-x), a laminated film of SiO2, HfSiO, and SixN(1-x), or the like, is formed in forming the gate insulating film.
    Type: Application
    Filed: August 12, 2004
    Publication date: March 3, 2005
    Applicant: Semiconductor Leading Edge Technologies, Inc.
    Inventors: Takaoki Sasaki, Takeshi Hoshi