Memc Electronic Materials, Inc.

Larry E Drafall

John D Holder

Robert D Shelley

Richard L Hansen

Leon A Allen

Robert M McCutchan

Robert J Falster

Richard Joseph Phillips

Steven Lawrence Kimbel

Harold W Korb

Joseph C Holzer

Kyong-Min Kim

Sadasivam Chandrasekhar

Kirk D McCallum

A crystal puller for growing monocrystalline silicon ingots according to the Czochralski method includes a housing and a crucible in the housing for containing molten silicon. The crucible has a side wall having a transmittance of at least about 80% generally throughout a light wavelength range of about 500 to about 2500 nanometers. A pulling mechanism is included for pulling a growing ingot upward from the molten silicon. In operation, polycrystalline silicon is charged to the crucible and the crucible is heated to melt the polycrystalline silicon for forming a molten silicon melt in the crucible. A seed crystal is then brought into contact with the molten silicon in the crucible and a monocrystalline silicon ingot is pulled up from the molten silicon.

Crystal puller and method for growing monocrystalline silicon ingots

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.

Surface-treated crucibles for improved zero dislocation performance

A Czochralski method of producing a single crystal silicon ingot having a uniform thermal history from a silicon melt contained in a crucible coaxial with the ingot. In the process the pulling rate of the end-cone of the ingot is maintained at a relatively constant rate which is comparable to the pulling rate for the second half of the main body of the ingot. During the pulling of the end-cone of the crystal at a constant rate, the process may be further refined by, either independently or in combination, increasing the heat supplied to the melt, reducing the crystal rotation rate and/or reducing the crucible rotation rate. The second half of the main body of a single crystal silicon ingot grown in accordance with this process exhibits a relatively uniform axial concentration of flow pattern defects and amount of oxygen precipitated.

Process for controlling thermal history of Czochralski-grown silicon

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St. Charles, MO, United States of America

Larry E Drafall