Patents by Inventor Richard L. Wallace

Richard L. Wallace 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 and apparatus for doping semiconductors
    Patent number: 7001455
    Abstract: Semiconductor materials such as silicon particles are doped by mixing the semiconductor material with a solution having a dopan and a solvent. The solvent is removed from the wetted surface of the particles of the semiconductor material, thereby yielding particles that are substantially free from the solvent and are uniformly coated with the dopant.
    Type: Grant
    Filed: August 8, 2002
    Date of Patent: February 21, 2006
    Assignee: Evergreen Solar, Inc.
    Inventors: Mary C. Cretella, Richard L. Wallace, Jr.
  • Continuous melt replenishment for crystal growth
    Patent number: 6217649
    Abstract: The invention features a method of continuous crystalline growth. A granular source material is introduced into a hopper. A volume of the granular source material exiting the hopper is disposed on a translationally moving belt. The volume of the granular source material forms an angle of repose with the moving belt. The granular source material disposed on the moving belt is continuously fed into a crucible comprising a melt of the granular source material at a rate based on the angle of repose, the speed of the belt, and the size of the opening of the hopper. A crystalline ribbon is continuously grown by solidifying the melt.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: April 17, 2001
    Assignee: Evergreen Solar, Inc.
    Inventors: Richard L. Wallace, Jr., Emanuel M. Sachs, Jennifer Martz
  • Melt depth control for semiconductor materials grown from a melt
    Patent number: 6200383
    Abstract: The invention features a method of controlling the depth of a melt for or crystal growth. According to the method, an input signal is applied through a crucible and a material disposed within the crucible. An output signal generated in response to the input signal is measured. The output signal relates to the depth of the melt. An amount of the source material introduced into the melt is adjusted to maintain the depth of the melt at a substantially constant level using the output signal.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: March 13, 2001
    Assignee: Evergreen Solar, Inc.
    Inventors: Richard L. Wallace, Jr., Richard C. Krauchune
  • Continuous melt replenishment for crystal growth
    Patent number: 6090199
    Abstract: The invention features a method of continuous crystalline growth. A granular source material is introduced into a hopper. A volume of the granular source material exiting the hopper is disposed on a translationally moving belt. The volume of the granular source material forms an angle of repose with the moving belt. The granular source material disposed on the moving belt is continuously fed into a crucible comprising a melt of the granular source material at a rate based on the angle of repose, the speed of the belt, and the size of the opening of the hopper. A crystalline ribbon is continuously grown by solidifying the melt.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: July 18, 2000
    Assignee: Evergreen Solar, Inc.
    Inventors: Richard L. Wallace, Jr., Emanuel M. Sachs, Jennifer Martz