Patents by Inventor Frank Marazita

Frank Marazita 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: 5493149
    Abstract: A bipolar lateral device is disclosed having a high BV.sub.ceo. The device is formed according to a single polysilicon process. In one embodiment silicide is excluded from the surface of the N+ doped polysilicon protecting the N- base width region of the device and the resulting device has a BV.sub.ceo of 8 to 10 V. In another embodiment, the silicide is excluded from the surface of the polysilicon protecting the n-base width region and the polysilicon is maintained as intrinsic polysilicon. The resulting device has a BV.sub.ceo of about 20 V. The devices are useful as voltage clamping devices in programmable logic circuits which must withstand a collector to emitter reverse bias voltage that is sufficient to program either vertical fuse or lateral fuse devices.
    Type: Grant
    Filed: February 23, 1994
    Date of Patent: February 20, 1996
    Assignee: National Semiconductor Corporation
    Inventors: Rick C. Jerome, Brian McFarlane, Frank Marazita
  • 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: 5355015
    Abstract: A lateral pnp transistor for use in programmable logic arrays. The lateral pnp has a layer of oxide disposed between a polysilicon layer and the base along the base width. The oxide layer prevents diffusion of the N+ dopant contained in the polysilicon layer into the N- base region. The base region thus remains N- and the resulting transistor has improved breakdown voltage characteristics while retaining the speed advantages of polysilicon contact layers. The lateral pnp transistor is manufactured by a method which requires minimal deviation from other methods used to manufacture lateral pnp transistors.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: October 11, 1994
    Assignee: National Semiconductor Corporation
    Inventors: Brian McFarlane, Frank Marazita, John E. Readdie
  • Patent number: 5350942
    Abstract: Low resistance contacts for establishing an electrical pathway to an integrated surface substrate are provided. The pathway is formed by the connection of a p+ doped channel stop region with a p+ doped extrinsic layer. P+ doped polysilicon contacts are positioned on the substrate surface. In one embodiment, a metal silicide layer connects the polysilicon contacts and overlies the p+ doped extrinsic layer.
    Type: Grant
    Filed: August 9, 1993
    Date of Patent: September 27, 1994
    Assignee: National Semiconductor Corporation
    Inventors: Rick C. Jerome, Frank Marazita
  • Patent number: 5298440
    Abstract: A bipolar lateral device is disclosed having a high BV.sub.ceo. The device is formed according to a single polysilicon process. In one embodiment silicide is excluded from the surface of the N+ doped polysilicon protecting the N- base width region of the device and the resulting device has a BV.sub.ceo of 8 to 10 V. In another embodiment, the silicide is excluded from the surface of the polysilicon protecting the n-base width region and the polysilicon is maintained as intrinsic polysilicon. The resulting device has a BV.sub.ceo of about 20 V. The devices are useful as voltage clamping devices in programmable logic circuits which must withstand a collector to emitter reverse bias voltage that is sufficient to program either vertical fuse or lateral fuse devices.
    Type: Grant
    Filed: January 22, 1993
    Date of Patent: March 29, 1994
    Assignee: National Semiconductor Corporation
    Inventors: Rick C. Jerome, Brian McFarlane, Frank Marazita
  • Patent number: 5298437
    Abstract: A method for fabricating a diode, for example, for use in a Schottky clamped transistor, which as a process step disposes a layer of oxide between the substrate and the overlying layer of polysilicon which must ultimately be etched away. The oxide layer permits use of an end point dry etch process which in turn allows greater miniaturization of the circuit over wet etch processes. Use of the end point process made feasible by the oxide layer also prevents overetch of the silicon material. As a result, a more ideal metal silicide anode-to-substrate Schottky barrier is formed with corresponding improvements in the diode ideality factor. In addition the oxide layer eliminates Schottky mask alignment problems and further improves diode performance characteristics by elimination of parasitic diodes. The process can be implemented with minimal deviation from other core processes used to fabricate similar circuits.
    Type: Grant
    Filed: July 28, 1992
    Date of Patent: March 29, 1994
    Assignee: National Semiconductor Corporation
    Inventors: Brian McFarlane, Frank Marazita, John E. Readdie
  • Patent number: 5139966
    Abstract: Low resistance contacts for establishing an electrical pathway to an integrated surface substrate are provided. The pathway is formed by the connection of a p+ doped channel stop region with a p+ doped extrinsic layer. P+ doped polysilicon contacts are positioned on the substrate surface. In one embodiment, a metal silicide layer connects the polysilicon contacts and overlies the p+ doped extrinsic layer.
    Type: Grant
    Filed: April 2, 1990
    Date of Patent: August 18, 1992
    Assignee: National Semiconductor Corporation
    Inventors: Rick C. Jerome, Frank Marazita