Patents by Inventor Geoffrey R. Woolhouse

Geoffrey R. Woolhouse 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: 4237601
    Abstract: Thick double heterostructure (Al,Ga)As wafers comprising layers of gallium arsenide and gallium aluminum arsenide on a metallized n-GaAs substrate are separated into individual devices for use as diode lasers. In contrast to prior art techniques employed with thinner wafers of mechanically cleaving the wafer in mutually orthogonal directions, the wafer is first separated into bars of diodes by a process which comprises (a) forming channels of substantially parallel sidewalls about 1 to 4 mils deep into the surface of the n-GaAs substrate (b) etching into the n-GaAs substrate with an anisotropic etchant to a depth sufficient to form V-grooves in the bottom of the channels and (c) mechanically cleaving into bars of diodes. The cleaving may be done by prior art techniques using a knife, razor blade or tweezer edge or by attaching the side of the wafer opposite to the V-grooves to a flexible adhesive tape and rolling the assembly in a manner such as over a tool of small radius.
    Type: Grant
    Filed: October 13, 1978
    Date of Patent: December 9, 1980
    Assignee: Exxon Research & Engineering Co.
    Inventors: Geoffrey R. Woolhouse, Harold A. Huggins, David W. Collins
  • Patent number: 4236296
    Abstract: Double heterostructure (Al,Ga)As wafer comprising layers of gallium arsenide and aluminum gallium arsenide on a metallized n-GaAs substrate are separated into individual devices for use as diode lasers. In contrast to prior art techniques of mechanically cleaving the wafer in mutually orthogonal directions, the wafer is first separated into bars of diodes by a process which comprises (a) forming an array of exposed lines on the n-side by photolithography to define the lasing ends of the diodes, (b) etching through the exposed metallized portion to expose portions of the underlying n-GaAs, (c) etching into the n-GaAs substrate with a V-groove etchant to a distance of about 1 to 2 mils less than the total thickness of the wafer and (d) mechanically cleaving into bars of diodes.
    Type: Grant
    Filed: October 13, 1978
    Date of Patent: December 2, 1980
    Assignee: Exxon Research & Engineering Co.
    Inventors: Geoffrey R. Woolhouse, Harold A. Huggins, Stephen I. Anderson, Frederick R. Scholl