The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jul. 24, 2001

Filed:

Jun. 01, 2000
Applicant:
Inventors:

Hiroshi Tomita, Yokohama, JP;

Tsuneo Ishii, Yamagata-ken, JP;

Chie Hongo, Yokohama, JP;

Assignee:

Other;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03C 1/900 ; C03C 2/300 ; C03C 2/100 ;
U.S. Cl.
CPC ...
C03C 1/900 ; C03C 2/300 ; C03C 2/100 ;
Abstract

A quartz glass which would not become a source for the contamination even if it contains metallic impurities. This quartz glass includes a region where a concentration of E′ center as measured by means of an electron spin resonance analysis is 3×10,cm,or more. This quartz glass can be manufactured by a method including the steps of forming an initial quartz glass by melting and quenching a raw material for quartz glass, and implanting therein an ion, which is capable of entering into an SiO,network of the initial quartz glass and substantially incapable of externally diffusing, to increase a concentration of E′ center in at least part of the initial quartz glass. This quartz glass can be manufactured by a method making use of a quartz glass raw material containing 0.01 to 0.1% by weight of silicon, by a method of irradiating ultraviolet ray to the initial quartz glass, or by a method of giving an abrasion damage to the surface of the initial quartz glass by means of sand blast.


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