Patents by Inventor Takao Hiraguchi

Takao Hiraguchi 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: 5094963
    Abstract: The present invention relates to a semiconductor device e.g., a CMOS, comprising a denuded region and a bulk-defect region, as well as a process for producing, e.g., CMOS. In a conventional CMOS, the distance (dp) between the bulk-defect region and p.sup.+ -type source or drain region (dp) is greater than the distance (dn) between the bulk-defect region and the p well (dn). As a result, a leakage current can be generated in the PN junction. In order to eliminate the problems caused due to dp>dn, the present invention forms in a semiconductor substrate a bulk-defect region having a depth which is nonuniform in accordance with the nonuniform depth of the semiconductor elements.
    Type: Grant
    Filed: September 5, 1990
    Date of Patent: March 10, 1992
    Assignee: Fujitsu Limited
    Inventors: Takao Hiraguchi, Kazunori Imaoka
  • Patent number: 4970568
    Abstract: The present invention relates to semiconductor device, a e.g., a CMOS, comprising a denuded region and a bulk-defect region, as well as the process for producing, e.g., a CMOS. In a conventional CMOS, the distance (dp) between the bulk-defect region and P.sup.+ -type source of drain region--(dp)--is greater than the distance (dn) between the bulk--defect--region and the P well--(dn)--. As a result, a leakage current can be generated in the PN junction. In order to eliminate the problems caused due to dp>dn, the present invention forms in a--semiconductor-substrate a bulk-defect region having a depth which is nonuniform in accordance with the nonuniform depth of the semiconductor elements.
    Type: Grant
    Filed: June 30, 1989
    Date of Patent: November 13, 1990
    Assignee: Fujitsu Limited
    Inventors: Takao Hiraguchi, Kazunori Imaoka