Browse Prior Art Database

Multi-Cable Lift Mechanism For Crystal Pulling Apparatus

IP.com Disclosure Number: IPCOM000048769D
Original Publication Date: 1982-Mar-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Kim, KM: AUTHOR [+3]

Abstract

The described apparatus employs a three-cable lift mechanism to pull and rotate crystals in a Czochralski crystal puller.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 84% of the total text.

Page 1 of 2

Multi-Cable Lift Mechanism For Crystal Pulling Apparatus

The described apparatus employs a three-cable lift mechanism to pull and rotate crystals in a Czochralski crystal puller.

Crystal pullers having a solid shaft to raise and rotate the crystal are about
8.5 meters high for large diameter crystals (10 cm or larger) having a length of 100 cm (or longer). If a cable lift is substituted for the solid shaft, machine height can be reduced to about 3.5 to 4.0 meters. However, when only a single cable is used, the rotation of the crystal tends to produce an orbital rotation of the crystal, resulting in a non-circular cross-section of the crystal, and non-uniform rotation. The situation is further aggravated by higher crystal rotation rates.

With a three-cable sling the height reduction advantage of a cable puller can be realized without the disadvantage of inducing orbital motion and non-uniform rotation. Such an apparatus is shown schematically in Fig. 1A, wherein the crucible support, heater, chamber and other lower puller structures are state of the art. The seed holder 10 is supported by a spherical swivel 11 capable of transmitting torque in the manner of a universal joint. This swivel is in turn supported by a weight 12 to which the three cables 13A, 13B and 13C are attached at equiangular positions. These cables pass upwardly through the draw chamber 14 to the cable winding (lift) and rotation mechanism 15, each respective motion of which is provided with a va...