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.
Patent No.:
Date of Patent:
Jan. 25, 1983
Filed:
Jan. 16, 1981
Applicant:
Inventor:
Karl A Schulke, Neuberg, DE;
Assignee:
Heraeus Quarzschmelze GmbH, Hanau, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03B / ;
U.S. Cl.
CPC ...
65 32 ; 65110 ; 65111 ; 65117 ; 148175 ;
Abstract
An improved method for the heat treatment of quartz-glass tubes at temperatures above 1200.degree. C. is disclosed wherein a pressure is maintained within the glass tube which is 3 to 110 mm Hg higher than the pressure on the external surface of the quartz tube over the heated area of the tube for at least the length of time that a temperature of 1200.degree. C. is exceeded. The process is particularly useful for the treatment of quartz-glass tubes within which silicon wafers are disposed for the purpose of diffusing doping agent into silicon wafers or of depositing doped epitaxial layers on silicon wafers.