Hemlock Semiconductor Corporation

Dow Corning Corporation

Hemlock Semiconductor Operations LLC

Chris Tim Schmidt

Arvid Neil Arvidson

Terence Lee Horstman

Michael John Molnar

Roger Dale Spencer, Jr

Kathryn Elizabeth Messner

Todd Stanley Graham

A method for recharging a crucible with polycrystalline silicon comprises adding flowable chips to a crucible used in a Czochralski-type process. Flowable chips are polycrystalline silicon particles made from polycrystalline silicon prepared by a chemical vapor deposition process, and flowable chips have a controlled particle size distribution, generally nonspherical morphology, low levels of bulk impurities, and low levels of surface impurities. Flowable chips can be added to the crucible using conventional feeder equipment, such as vibration feeder systems and canister feeder systems.

Flowable chips and methods for the preparation and use of same, and apparatus for use in the methods

A method for processing polycrystalline silicon workpieces to form size distributions of polycrystalline silicon pieces suitable for use in a Czochralski-type process includes: (1) preparing a polycrystalline silicon workpiece by a chemical vapor deposition process; (2) fracturing the polycrystalline silicon workpiece into a mixture of polycrystalline silicon pieces, where the polycrystalline silicon pieces have varying sizes; and (3) sorting the mixture of polycrystalline silicon pieces into at least two size distributions. Step (2) may be carried out by a thermal shock process. Step (3) may be carried out using a rotary indent classifier. A rotary indent classifier for performing the method includes: (i) a rotating cylinder having a circumferential edge with indents arrayed in increasing size from a first end of the cylinder to a second end of the cylinder, and (ii) a conveyor running longitudinally adjacent the cylinder, for conveying silicon pieces from the first end of the cylinder to the second end of the cylinder.

Method and apparatus for improving silicon processing efficiency

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Auburn, MI, United States of America

Chris Tim Schmidt