Ultra Clean Holdings helps chip makers handle gases under ultraclean conditions. The company, which does business as Ultra Clean Technology (UCT), designs, engineers, manufactures, and tests customized gas, liquid, and catalytic steam generation delivery systems used in the production of semiconductors. It developed a catalytic steam generator designed for use in several chip production steps that call for high-purity steam. UCT, which was founded as a subsidiary of Mitsubishi Corporation in 1991, draws almost 90% of its sales from Applied Materials, Intuitive Surgical, Lam Research, and Novellus Systems. The company gets nearly all of its sales in the US.