What is "sumco"

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%.

SUMCO is listed on the first section of the Tokyo Stock Exchange and is a constituent of the Nikkei 225 stock index.