Process and apparatus for the semicontinuous production of silicon moldings

US4175610A · kind A · utility

Assignee

• Wacker-Chemitronic Gesellschaft fur Elektronik Grundstoffe mbH · DE

Inventors

• Helmut Zauhar
• Bernhard Authier · Burghausen, DE
• Roland Luptovits · Emmerting, DE
• Leonhard Schmidhammer · Tittmoning, DE

Key dates

• Filing date: Jul 17, 1978
• Grant date: Nov 27, 1979
• Expiry date: Jul 17, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B11/00
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The invention relates to a process and apparatus for manufacturing silicon astings or moldings, having a columnar structure of single-crystal regions of crystal with a preferential crystallographic orientation, and which can be manufactured cheaply and in large numbers in a semi-continuous mode of production. Liquid silicon is cast in a casting station, under an inert gas and preferably under reduced pressure, preferably in graphite molds which are exposed to a temperature gradient of 200.degree. to 1,000.degree. C. After cooling, the silicon is withdrawn automatically via a transport chamber connected to the casting station into special cooling stations, while the casting station is reloaded with an empty mold for repeating the process. The silicon blocks which have preferably been produced by this procedure are use as basic material for inexpensive solar cells having efficiencies of more than 10%, after they have been sawn into individual small wafers and have been doped and lead-bonded.