Patents by Inventor John E. Readdie

John E. Readdie 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: 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: 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: 5296406
    Abstract: A Schottky diode is presented which has reduced minority carrier injection and reduced diffusion of the metallization into the semiconductor. These improvements are obtained by interposing a layer comprising a mixture of silicon and chromium between the anode metallization layer and the semiconductor in a Schottky diode. The layer including chromium acts an effective barrier against the diffusion of the metallization layer into the semiconductor, and at the same time reduces the amount of minority carrier injection into the substrate. The layer including chromium requires no addition photolithograpic masks because it can be plasma etched using the metallization layer as a mask after that layer has been patterned.
    Type: Grant
    Filed: July 7, 1993
    Date of Patent: March 22, 1994
    Assignee: Linear Technology Corporation
    Inventors: John E. Readdie, Benjamin H. Kwan, Jeng Chang
  • Patent number: 5254869
    Abstract: A Schottky diode is presented which has reduced minority carrier injection and reduced diffusion of the metallization into the semiconductor. These improvements are obtained by interposing a layer comprising a mixture of silicon and chromium between the anode metallization layer and the semiconductor in a Schottky diode. The layer including chromium acts an effective barrier against the diffusion of the metallization layer into the semiconductor, and at the same time reduces the amount of minority carrier injection into the substrate. The layer including chromium requires no addition photolithograpic masks because it can be plasma etched using the metallization layer as a mask after that layer has been patterned.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: October 19, 1993
    Assignee: Linear Technology Corporation
    Inventors: John E. Readdie, Benjamin H. Kwan, Jeng Chang