Patents by Inventor K. Paul Muller

K. Paul Muller 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).

  • Formation of a bottle shaped trench
    Patent number: 5891807
    Abstract: A method for forming a bottle shaped trench 20 in a semiconductor substrate 10 includes reactive ion etching a trench having a tapered top portion 25 in the semiconductor device and continuing to reactive ion etch while increasing the temperature of the semiconductor device to impart a reentrant profile 22 to the trench.
    Type: Grant
    Filed: September 25, 1997
    Date of Patent: April 6, 1999
    Assignees: Siemens Aktiengesellschaft, International Business Machines Corporation
    Inventors: K. Paul Muller, Rajiv M. Ranade, Stefan Schmitz
  • Methods for roughening and volume expansion of trench sidewalls to form high capacitance trench cell for high density dram applications
    Patent number: 5877061
    Abstract: Trench cells with increased storage capacity are prepared with roughened sidewalls using a layer of grainy polysilicon or hemispherical grain polysilicon. The top collar region of the trench is protected with oxide while the lower portion of the trench coated with polysilicon or hemispherical grain polysilicon is etched isotropically. The trench structure created has roughened sidewalls for increased volume of storage.
    Type: Grant
    Filed: February 25, 1997
    Date of Patent: March 2, 1999
    Assignee: International Business Machines Corporation
    Inventors: Scott D. Halle, ChorngLii Hwang, K. Paul Muller