Polycrystalline silicon rod, processing method for polycrystalline silicon rod, method for evaluating polycrystalline silicon rod, and method for producing FZ single crystal silicon
US11167994B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 2020 |
| Grant date | Nov 9, 2021 |
| Priority date | — |
| Expiry date | Sep 4, 2040 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B13/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.