Method and apparatus for measuring the monocrystal diameter and the melt level during crucible drawing in the Czochralski process
US4832496A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 29, 1986 |
| Grant date | May 23, 1989 |
| Priority date | — |
| Expiry date | Oct 29, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/105
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for measuring the diameter of a monocrystal during crucible drawing determines the brightness profile at the melt/monocrystal change-over point. The spacial position of maxima in the brightness profile in relation to a reference point indicates the diameter. The brightness profile is obtained by optically scanning the melt/monocrystal change-over point with a mirror rotating about a horizontal axis, applying the optical beam reflected by the rotating mirror to a row of photosensitive elements in parallel with the axis, and analyzing the outputs corresponding to the brightness profile for determining the diameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.