Wacker-chemitronic Gesellschaft Fur Elektronik-grundstoffe Mbh

Wacker-chemie Gmbh

Winfried Lang

Rudolf Griesshammer

Franz Koppl

Heinz-Jorg Rath

Erhard Sirtl

Bernhard Authier

Michael Schwab

Herbert Straussberger

Rudolf Riedle

Willi Streckel

Dietrich Schmidt

Anton More

Werner Zulehner

Johann Hofer

Thorgard Zainer

Ernst Muhlhofer

Johann Braunsperger

Rudolf Pachnek

A method is described according to which articles of quartz glass, particrly quartz crucibles for use in crucible pulling according to Czochralski of high-purity synthetic quartz glass can be produced. High-purity silicon tetrachloride is hydrolized with water. The hydrolysis product is separated, dried, shaped, sintered and superficially fused.

Method for producing articles of high-purity synthetic quartz glass

The invention relates to a process for treating elemental silicon and ferrosilicon with slag having the following analytical composition:

Process for treating silicon and ferrosilicon with slag

Waste gases resulting from the production of silicon in connection with the ormation or decomposition of chlorosilanes, which gases always contain hydrogen chloride, can be worked up without removal of the hydrogen chloride. For this purpose, the waste gases which, after separation from the chlorosilanes, only contain hydrogen and hydrogen chloride, are subjected to combustion with addition of air and, after addition of silicon tetrachloride, the result being highly dispersed SiO.sub.2. The hydrogen chloride then remaining in the gaseous phase is returned to the process stream for production of trichlorosilane.

Process for processing waste gases resulting during the production of

Process for producing large-size, self-supporting plates of silicon deposd from the gaseous phase on a substrate body, which comprises heating a graphite substrate to deposition temperature of silicon, which is deposited on the substrate from a gaseous compound to which a dopant has been added until a layer of about 200 to 650 .mu.m has formed, subsequently melting 40-100% of this layer from the free surface downward, resolidifying the molten silicon by adjustment of a temperature gradient from the substrate body upward, and finally separating the silicon therefrom. The plates so formed are used primarily for making solar cells.

Process for producing large-size, self-supporting plates of silicon

Trichlorosilane or silicon tetrachloride is prepared by reacting metallic uminum-containing silicon in a reaction zone with hydrogen chloride or chlorine at a temperature between about 260.degree. and about 1200.degree. C, the reaction gas is then cooled to 40.degree. to 130.degree. in a cooling zone through which the velocity of flow is maintained at between 3 and 30 meters per second, and finally filtered.

Process for the manufacture of trichlorosilane and silicon tetrachloride

A process for producing large-size, substrate-based semiconductor material of silicon deposited on a substrate body from the gaseous phase, which comprises the steps of heating a substrate body by direct current passage to deposition temperature, contacting said body with a gaseous silicon-containing mixture to which a dopant has been added, until a deposit having a thickness from about 10 to 200 .mu.m has been formed, subsequently melting 80 to 100% of the deposited silicon layer from the free surface downward, and resolidifying the molten silicon by adjustment of a temperature gradient from the substrate body upward. Large-sized plates obtained by cutting up the semiconductor material are used as solar cells.

Process for producing large-size substrate-based semiconductor material

Halogenosilanes and halogenogermanes which are contaminated by a boron-coining impurity are purified by treatment with an effective amount of a hydrated metal oxide or a hydrated silicate containing from about 3 to about 8% by weight of water, and then distilling the treated halogenosilane or halogenogermane at a temperature about 3.degree. to about 15.degree. C above its boiling temperature, and at atmosphere pressure.

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Burghausen, Germany

Winfried Lang