| 摘要 |
PURPOSE:To obtain a structure that a low temperature range is produced in an atmosphere by forming at the peripheral edge of a mount in a vessel of hermetically sealing structure and covering the outer periphery of the vessel with a heat insulating material. CONSTITUTION:The peripheral edge of the surface of a wafer mount 1 is formed as a vessel 2 of hermetically sealing structure, the outer periphery is covered with a heat insulating material 3, a thermos 4 is mounted in the vessel 2, a metal strip 5 is connected with the lower part of the mount 1 to be suspended, and its end is inserted into the bottle 4. Liquefied gas is fed by an inlet tube 6 into the bottle 4 to cool the strip 5 with a cold material to transfer the heat of the mount 1. Thus, the cold material of the quantity of heat which cooled the mount 1 is evaporated to be filled in the vessel 2 of the hermetically sealing structure. Further, the evaporated gas is heated by an electric heater 9 on the way through a drain tube 7 to be injected in parallel with the whole surface of the mount 1. Thus, the surface of the mount 1 is separated from the atmosphere to prevent the water content in the atmosphere from being dew-condensed or iced. An electric heater 11 is secured to the rear side of the mount 1 to control the mount 1 to an arbitrary temperature.
|
