Polycrystalline silicon can be one of the purest elements in the world. After air and water, silicon is the most important non-carbon (inorganic) substance in the world. Silicon is most often companioned with oxygen to form sand -- silicon dioxide. When the oxygen is stripped from the silicon, crude polycrystalline silicon remains. Ultra pure poly is used in the semiconductor industry. To purify the crude poly, chemical plants that look like petrochemical oil refineries are required.
Major polysilicon manufacturers include:
- Hemlock Semiconductor
- Wacker Chemie
- Mitsubishi (Japan and America)
- As well as several small sites in China and CIS.
The first 7 companies cover over 75% of the worldwide production capacity of polysilicon.