×

Method for controlling growth of a silicon crystal

  • US 5,653,799 A
  • Filed: 06/02/1995
  • Issued: 08/05/1997
  • Est. Priority Date: 06/02/1995
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for use in combination with an apparatus for growing a silicon crystal from a silicon melt, said method for determining a diameter of the silicon crystal being pulled from the silicon melt, said silicon melt having a surface with a meniscus which is visible as a bright area adjacent the silicon crystal, said method comprising the steps of:

  • generating an image pattern of a portion of the bright area adjacent the silicon crystal with a camera;

    detecting an optical characteristic of the image pattern;

    defining edges in the image pattern as a function of the detected optical characteristic, said defined edges corresponding to an edge of the bright area;

    defining a curve corresponding to the shape of the meniscus, said defined curve representing a circle that fits the defined edges in the image pattern corresponding to the edge of the bright area;

    determining a dimension of the defined curve; and

    determining the diameter of the silicon crystal as a function of the determined dimension of the defined curve.

View all claims
  • 17 Assignments
Timeline View
Assignment View
    ×
    ×