Patents by Inventor Lawrence K. C. Lam

Lawrence K. C. Lam 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: 5436496
    Abstract: A vertical fuse structure including a lightly-doped shallow emitter 30 provides improved fusing characteristics. The structure includes a buried collector 14, an overlying base 30, and an emitter 44 above the base 30. In one preferred embodiment, the emitter 44 extends about 0.2 microns from the upper surface and has a dopant concentration of about 8.times.1019 atoms of arsenic per cubic centimeter at the surface. A lightly doped base region 30 extends for about 0.46 microns below the emitter 44 to the collector 14. The upper surface of emitter 44 includes a metal contact 60. Heating the metal 60/emitter 44 interface to its eutectic melting point using a current or voltage pulse causes the aluminum to short through the emitter 44 to the base 30. Shorting the emitter programs the fuse. A second preferred embodiment uses polysilicon as an interconnecting medium.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: July 25, 1995
    Assignee: National Semiconductor Corporation
    Inventors: Rick C. Jerome, Ronald P. Kovacs, George E. Ganschow, Lawrence K. C. Lam, James L. Bouknight, Frank Marazita, Brian McFarlane, Ali Iranmanesh
  • Patent number: 5059555
    Abstract: An improved method for fabricating polysilicon Schottky clamped transistors and vertical fuse devices in the same semiconductor structure is disclosed. The resulting structure yields an improved Schottky clamped transistor and vertical fuse device. The improved Schottky transistor has a silicide rectifying contact between the base and collector of the transistor, the vertical fuse is provided with a direct contact between an aluminum contact metal and a polysilicon emitter contact.
    Type: Grant
    Filed: August 20, 1990
    Date of Patent: October 22, 1991
    Assignee: National Semiconductor Corporation
    Inventors: Ali A. Iranmanesh, Lawrence K. C. Lam