Memc Electronic Materials, Inc.

Makoto Kojima

Hiroyo Haga

Shigemi Saga

Yasuhiro Ishii

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.

Controlled neck growth process for single crystal silicon

A Czochralski method of producing a single crystal silicon ingot having a uniform thermal history. In the process, the power supplied to the side heater is maintained substantially constant throughout the growth of the main body and end-cone of the ingot, while power supplied to a bottom heater is gradually increased during the growth of the second half of the main body and the end-cone. The present process enables an ingot to be obtained which yields wafers having fewer light point defects in excess of about 0.2 microns, while having improved gate oxide integrity.

Growing community of inventors

Utsunomiya, Japan

Makoto Kojima