MEMC Electronic Materials, Inc. designs, manufactures, and sells silicon wafers for the semiconductor industry worldwide. Its products include prime polished wafers, such as OPTIA and annealed products; epitaxial wafers consisting of thin silicon layer grown on the polished surface of the wafer; and test/monitor wafers for testing semiconductor fabrication lines and processes. The company’s products are used in the manufacture of various semiconductor devices, including microprocessor, memory, logic, and power devices, as well as the starting material for solar cells. Its customers comprise semiconductor device manufacturers, including the memory, microprocessor, and applications specific integrated circuit manufacturers, foundries, and solar cell and module manufacturers. The company was founded in 1984 and is based in St. Peters, Missouri.