| 摘要 |
PURPOSE:To control the temperature of a wafer constantly by forming a gas passage, providing a venturi by contracting part of the passage, and connecting it with a vacuum hole. CONSTITUTION:A gas passage 5 is feeding temperature control gas into a body 1 is formed adjacent to a wafer supporting surface 1a, part of the passage 5 is contracted to form a venturi 5a in the lower portion of the wafer supporting surface 1a, and the venturi 1a is connected with the vacuum hole 6 of the surface 1a. Since the passage area is contracted in the venturi 5a when the gas is fed to the passage 5, a pressure difference occurs before and after the throttle to generate negative pressure in the venturi 5a. Accordingly, the back surface of a semiconductor wafer 2 disposed on the surface 1a is attracted in vacuum by the negative pressure through the hole 6 to hold the wafer 2 on the surface 1a. Thus, the temperature control of the wafer can be accurately performed. |
