Patents by Inventor Walter R. M. Stepko

Walter R. M. Stepko 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 annealing a sublimation grown crystal
    Patent number: 7767022
    Abstract: A crystal is sublimation grown in a crucible by way of a temperature gradient in the presence of between 1 and 200 Torr of inert gas. The pressure of the inert gas is then increased to between 300 and 600 Torr, while the temperature gradient is maintained substantially constant. The temperature gradient is then reduced and the temperature in the crucible is increased sufficiently to anneal the crystal. Following cooling and removal from the crucible, the crystal is heated in the presence of oxygen in an enclosure to a temperature sufficient to remove unwanted material from the crystal. Following cooling and removal from the enclosure, the crystal surrounded by another instance of the source material is heated in a crucible in the presence 200 and 600 Torr of inert gas to a temperature sufficient to anneal the crystal.
    Type: Grant
    Filed: April 19, 2007
    Date of Patent: August 3, 2010
    Assignee: II-VI Incorporated
    Inventors: Avinash K. Gupta, Ilya Zwieback, Jihong Chen, Marcus Getkin, Walter R. M. Stepko, Edward Semenas