WAFER HOLDER AND SUCTION RELEASING METHOD OF WAFER

摘要

PURPOSE: To provide a holder for protecting a wafer from electrostatic breakage to be sucked and released. CONSTITUTION: The wafer holder 10 is provided with a wafer holding plate 18 forming a plurality of fluid circulation holes on an upper surface. The wafer holding plate 18 selectively communicates with a fluid discharge mechanism 28, a fluid supply mechanism 30 and a pure water supply unit 32 through changeover valves 24 and 26. The fluid supply mechanism 30 is provided with a mixing unit 36 producing carbon dioxide water and a regulator 38 for controlling pressure and a flow rate of the carbon dioxide water. When the first changeover valve 24 is operated, the regulator 38 supplies the carbon dioxide water to the fluid circulation hole 20. The wafer 12 floats more than the carbon dioxide water whose specific resistance is smaller than purity on the wafer holding plate 18. Thereby a minute element can be protected.