Crucible of fused vitreous silica

US4019645A · kind A · utility

Assignee

• Heraeus-Schott Quarzschmelze GmbH

Inventors

• Karl Seiler
• Martin Selke
• Oswald Siegling
• Heinz Herzog · Karlstein, DE
• Horst Albrecht · Hanau, DE
• Heinrich Mohn · Hailer, DE

Key dates

• Filing date: Dec 3, 1973
• Grant date: Apr 26, 1977
• Expiry date: Dec 3, 1993

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T117/1032
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A crucible of pure transparent silica glass or pure translucent or opaque silica glass for the production of monocrystals used in making semiconductor elements which includes a hollow cylindrical part and a welded-on head. The head end of the hollow cylindrical part is formed from a tube with a head margin portion constricted towards the tube axis which is formed by shaping one end of the tube. A plate is welded into the aperture formed by the constricted head margin portion and has an area equal to at least one-tenth and at most four-fifths of the total head area made up by the head margin portion and the head.