Memc Electronic Materials, Inc.

Robert M McCutchan

John D Holder

Robert D Shelley

Larry E Drafall

Richard L Hansen

Leon A Allen

A method of reinforcing a crucible for the containment of molten semiconductor material in a Czochralski process, and of inhibiting formation of dislocations within a single crystal grown by the process. The crucible includes a body of vitreous silica having a bottom wall and a sidewall formation extending up from the bottom wall and defining a cavity for holding the molten semiconductor material. The sidewall formation and bottom wall each have an inner and an outer surface. A first devitrification promoter is deposited on the inner surface of the sidewall formation at a temperature below about 600.degree. C. The deposit is such that, when the crucible is heated above 600.degree. C., a first layer of substantially devitrified silica forms on the inner surface which is capable of promoting substantially uniform dissolution of the inner surface and reducing the release of crystalline silica particulates into the molten semiconductor material as a crystal is pulled from the molten semiconductor material. A second devitrification promoter is deposited on the outer surface of the sidewall formation at a temperature below about 600.degree. C. The deposit is such that, when the crucible is heated above 600.degree. C., a second layer of substantially devitrified silica forms on the outer surface which is capable of reinforcing the vitreous silica body.

Methods for improving zero dislocation yield of single crystals

A crucible in which a semiconductor material is melted and held during a crystal growing process. The crucible includes a body of vitreous silica having a bottom wall and a sidewall formation extending up from the bottom wall and defining a cavity for holding the molten semiconductor material. The sidewall formation has an inner and an outer surface. A first devitrification promoter on the inner surface of the sidewall formation is distributed such that a first layer of substantially devitrified silica is formed on the inner surface of the crucible which is in contact with the molten semiconductor material when the semiconductor material is melted in the crucible during the crystal growing process. A second devitrification promoter on the outer surface of the sidewall formation is distributed such that a second layer of substantially devitrified silica is formed on the outer surface of the crucible when the semiconductor material is melted in the crucible during the crystal growing process. The first substantially devitrified silica layer is such that it promotes uniform dissolution of the inner surface and in so doing significantly reduces the release of crystalline silica particulates into the molten semiconductor material as a crystal is pulled from the molten semiconductor material. The second substantially devitrified silica layer is such that it reinforces the vitreous silica body.

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Lake St. Louis, MO, United States of America

Robert M McCutchan