SUMCO Corporation (株式会社SUMCO, Kabushiki-gaisha Samuko, formerly Silicon United Manufacturing Corporation and Sumitomo Mitsubishi Silicon Corporation) is a Japanese semiconductor company, manufacturing silicon wafers for semiconductor manufacturers worldwide. The company was established in 1999 as a joint venture between Mitsubishi Materials Corporation and Sumitomo Metal Industries and as of 2013 is the second largest silicon wafer producer in the world, after Shin-Etsu Handotai, with a market share of 30%.