Three are three main technologies to produce polysilicon. The 'modified Siemens process' is currently the dominant technology in China. Trichlorosilane (TCS) is produced using two readily available metallurgical-grade silicon (of 95-99% purity) and liquid chlorine. After being purified through distillation, the TCS is. The polysilicon industry has increasingly consolidated, with the top-five companies accounting for 73% of global production in 2020 compared to 60% in. In June 2021, US Customs and Border Protection issued a 'withhold release order' targeting a major supplier of metallurgical silicon. Polycrystalline silicon, or multicrystalline silicon, also called polysilicon, poly-Si, or mc-Si, is a high purity, form of, used as a raw material by the solar and. Polysilicon is produced from by a chemical purification process, called the. This process involves of volatil.