Patents by Inventor Manfred Dahmen

Manfred Dahmen 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).

  • Method of manufacturing a power transistor
    Patent number: 3970487
    Abstract: A method for manufacturing a power transistor having a highly doped emitter zone and a narrow base zone with a flat doping profile.In a long-term diffusion step ensuring the flat doping profile, the base zone is diffused into a lowly doped substrate serving as a collector. In a subsequent etching process, the base zone is etched down to a shell-shaped remainder. A large area, highly doped emitter zone with a steep doping profile and thus a high emitter efficiency is introduced into this shell-shaped remainder in a short-term diffusion step.
    Type: Grant
    Filed: June 16, 1975
    Date of Patent: July 20, 1976
    Assignee: International Business Machines Corporation
    Inventors: Manfred Dahmen, Anneliese Ritzhaupt, Manfred Zurheide