Memc Electronic Materials, Inc.

Hiroyo Haga

Mohsen Banan

Takaaki Aoshima

Makoto Kojima

Shigemi Saga

The present invention relates to a process for forming single crystal silicon ingots or wafers that contain an axially symmetric region in which vacancies are the predominant intrinsic point defect, that are substantially free of oxidation induced stacking faults, and are nitrogen doped to stabilize oxygen precipitation nuclei therein.

Nitrogen-doped silicon substantially free of oxidation induced stacking faults

A single crystal silicon, ingot or wafer form, which contains an axially symmetric region in which vacancies are the predominant intrinsic point defect, is substantially free of oxidation induced stacking faults and is nitrogen doped to stabilize oxygen precipitation nuclei therein, and a process for the preparation thereof.

A process for preparing a single crystal silicon in accordance with the Czochralski method, is provided. More specifically, by quickly reducing the pull rate at least once during the growth of the neck portion of the single crystal ingot, in order to change the melt/solid interface shape from a concave to a convex shape, the present process enables zero dislocation growth to be achieved in a large diameter neck within a comparably short neck length, such that large diameter ingots of substantial weight can be produced safely and at a high throughput.

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Utsunomiya, Japan

Hiroyo Haga