Patents Examined by Pelisa Hiteshew
  • Patent number: 6117234
    Abstract: The object of the present invention is to provide an apparatus and a method for preventing dropping of a single crystal having large diameter and heavy weight in a chamber with reduced pressure and for pulling it in reliable and safe manner. After a seed crystal 24a is immersed in Si melt in a quartz crucible 14, the seed crystal is pulled up, and a neck portion 1a with small diameter is formed under the seed crystal 24a, and a spherical constricted portion 1b is formed under the neck portion 1a, whereby a tip 23a of a single crystal support 23 is opened so that it does not come into contact with the constricted portion 1b under pulling operation.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: September 12, 2000
    Assignee: Super Silicon Crystal Research Institute Corp.
    Inventor: Hirotoshi Yamagishi
  • Patent number: 6022411
    Abstract: The object of the present invention is to prevent the single crystal during pulling operation from turning to polycrystal when the single crystal under pulling operation is gripped by a gripper and to achieve the gripping automatically. When a wire 1 is moved down to immerse a seed crystal 3 into surface of a Si melt 11 in a quartz crucible 10, arms 12 and 13 wait at such positions that tips do not come into contact with the Si melt 11, and tips of the gripping arm 12 are opened so that the tips are not brought into contact with a portion with larger diameter 5 during pulling operation. By pulling up the wire 1, a neck portion 4, a portion with larger diameter 5, a constricted portion 6, and a crystal main portion 7 are formed under the seed crystal 3. When a sensor 14 detects that upper surface of the portion with larger diameter 5 has come into contact with the tips of the contact/detecting arm 13 during pulling operation, tips of the gripping arm 12 are closed and grip the constricted portion 6.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: February 8, 2000
    Assignee: Super Silicon Crystal Research Institute Corp.
    Inventor: Makoto Kuramoto