Patent · US Expired

Crystal pulling method

US5882397A · kind A · utility

9Cited by
3References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 6, 1997
Grant dateMar 16, 1999
Priority date
Expiry dateOct 6, 2017

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T117/1072
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

In a crystal pulling method in which a growing single crystal is initially pulled by a seed chuck and subsequently pulled by lifting jig in the middle of the pulling operation, the speed Va of the seed chuck relative to the lifting jig is decreased, while the rising speed Vb of the lifting jig increases, from a first point where switching of the pulling mechanism from the seed chuck to the lifting jig is started. The total speed Vt=Vb+Va is constantly maintained at a desired pulling speed V up to a third point where the shifting of the load from the seed chuck to the lifting jig is started. Subsequently, the total speed Vt is made less than the desired pulling speed V from the third point where the shifting of the load from the seed shuck to the lifting jig is started. This enables accurate growth of a crystal.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.