Hemlock Semiconductor Corporation is the largest producer of polysilicon in the United States. It is a subsidiary of Dow Corning founded in 1961, and named after Hemlock, Michigan, the location of its factory. Its current facilities produce some 36,000 tons of polysilicon, ranking it among the top five producers worldwide. 
The company expanded with the Japanese joint venture partners Shin-Etsu Chemical and Mitsubishi Materials, for a new $1.2 billion plant opening near Clarksville, Tennessee. Though it officially opened in 2012, chemicals were never inventoried and no product was made. The plant was under negotiations in 2011 for a further $3 billion expansion, to keep pace with manufacturing competition from China. 
In December 2014, Hemlock Semiconductor Corporation announced the permanent closure of the $1.2 billion Tennessee plant, due to adverse conditions from industry oversupply and ongoing challenges from global trade disputes. Many of the approximately fifty employees in Tennessee were offered employment positions in Michigan at the Hemlock Semiconductor or Dow Corning facilities, and the rest received severance packages. 
Dow Corning announced that June 1, 2016 would be "day one" such that  Dow Chemical Company will assume 100% ownership of the Dow Corning Corporation, concluding the 73-year joint venture between Dow Chemical and Corning Inc.. At this time Hemlock Semiconductor will continue as an independently run entity with three minority shareholders: Dow Chemical will own 40.25%, Corning Inc will own 40.25%, and Shin-Etsu Chemical will own 19.5%.
- PV-tech.org: Hemlock Semiconductor Corporation
- Knoxnews.com: Hemlock Semiconductor Corp. plans expansion; May 2011.
- Hscpoly.com: Hemlock Semiconductor Corp. manufacturing-facility-closure
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