Hemlock Semiconductor Corporation
Hemlock Semiconductor Corporation, based in Michigan, is the largest producer of polysilicon in the United States. It is a subsidiary of Dow Corning founded in 1961, and named after the town of Hemlock, Michigan.
Its current facilities produce some 36,000 tons of polysilicon, ranking it among the top 5 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. It opened in 2012. 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.
In December 2015, Google announced that they would be buying the facility, and investing more than $600 million to turn it into their 15th datacenter.