Michael P Keevan

US Patent:

20120177559, Jul 12, 2012

Filed:

Jan 7, 2011

Appl. No.:

12/986794

Inventors:

Laura Prine - Theodore AL, US
Richard M. Halstead - Spanish Fort AL, US
Michael W. Keevan - Theodore AL, US

Assignee:

Mitsubishi Materials Corporation - Tokyo
Mitsubishi Polycrystalline Silicon America Corporation (MIPSA) - Theodore AL

International Classification:

C01B 33/039
B01J 8/18

US Classification:

423349, 422139

Abstract:

The invention concerns an apparatus and a method for manufacturing polycrystalline silicon having a reduced amount of boron compounds. The invention provides an apparatus and a method which mix an unpurified trichlorosilane with purified hydrogen gas from an activated carbon tower. The mixture is sent to a distillation apparatus for purifying trichlorosilane.

US Patent:

20160152481, Jun 2, 2016

Filed:

Dec 1, 2014

Appl. No.:

14/556640

Inventors:

- Theodore AL, US
Michael W. Keevan - Theodore AL, US

International Classification:

C01B 33/039
B01J 8/24
C01B 33/021

Abstract:

The present invention relates to an apparatus and a method for producing polycrystalline silicon having a reduced amount of boron compound impurities. Especially, the boron compounds are removed from the process for producing polycrystalline silicon, while the trichlorosilane is purified by distillation. The invention feeds condensed liquid trichlorosilane into a primary distillation tower below the liquid level inside the primary distillation tower thereby scrubbing the boron impurities upon contact inside the primary distillation tower. There result is trichlorosilane leaving the primary distillation tower with total amount of boron at least 10 times less.