Title:
DEWAR FLASK, PHOTOLUMINESCENCE MEASUREMENT DEVICE, CONCENTRATION MEASUREMENT METHOD, AND SILICON MANUFACTURING METHOD
Document Type and Number:
WIPO Patent Application WO/2022/030093
Kind Code:
A1
Abstract:
The present invention achieves a large reduction in the burden on a vacuum operator and a large reduction in vacuum cost, when measuring the concentration of impurities included in silicon, said measurement being performed in liquid helium and according to a photoluminescence method. A glass that is a material forming an inner cylinder Dewar flask (2) has an SiO2 content of 65 wt% to 75 wt%, and has an average coefficient of thermal expansion of 25×10-7/°C to 55×10-7/°C when the temperature of the glass is 20°C to 300°C.
Inventors:
SAKAI JUNYA (JP)
YAMAMOTO TOMOHIRO (JP)
YAMAMOTO TOMOHIRO (JP)
Application Number:
PCT/JP2021/021135
Publication Date:
February 10, 2022
Filing Date:
June 03, 2021
Export Citation:
Assignee:
TOKUYAMA CORP (JP)
International Classes:
G01N21/64; C03C3/091; C03C3/108; G01N1/06
Foreign References:
| JP2013123704A | 2013-06-24 | |||
| JP2019120359A | 2019-07-22 |
Other References:
ANONYMOUS: "Stainless and glass cryostats", KAWAGUCHI LIQUEFACTION CHEMICAL - BLOG, JP, pages 1 - 3, XP009534889, Retrieved from the Internet [retrieved on 20210813]
"Electronics and Information Technology Industries Information Standard JEITA EM-3601A High Purity Polycrystalline Silicon Standard", September 2004, JAPAN ELECTRONICS AND INFORMATION TECHNOLOGY INDUSTRIES ASSOCIATION
F.J. NORTON: "Helium Diffusion Through Glass", JOURNAL OF THE AMERICAN CERAMIC SOCIETY, vol. 36, 1953, pages 90 - 96
See also references of EP 4194841A4
"Electronics and Information Technology Industries Information Standard JEITA EM-3601A High Purity Polycrystalline Silicon Standard", September 2004, JAPAN ELECTRONICS AND INFORMATION TECHNOLOGY INDUSTRIES ASSOCIATION
F.J. NORTON: "Helium Diffusion Through Glass", JOURNAL OF THE AMERICAN CERAMIC SOCIETY, vol. 36, 1953, pages 90 - 96
See also references of EP 4194841A4
Attorney, Agent or Firm:
HARAKENZO WORLD PATENT & TRADEMARK (JP)
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