| 摘要 |
PURPOSE:To raise the efficiency of cleaning operation and to improve the quality of etching, by forming a gas outlet port for blowing out gas to remove substances captured by a trap body at a position near the bottom of the trap body, and thereby carrying out trap cleaning operation in an extremely effective manner. CONSTITUTION:Substances attached to a trap body 1 is separated by heating the bottom of the outer wall 14 of the trap body 1 by heated nitrogen gas blown out from a nitrogen gas outlet port 18 that is formed at a position near the bottom of the trap body 1. At the same time, the outer wall 14 near the bottom of the trap body 1 is also heated gradually, so that the substances attached to the trap body 1 drops, in the form of droplets, toward the bottom of the trap body 1 along the outer wall 14. Here, since the bottom of the trap body 1 is heated to about 100 deg.C, liquefied substances are vaporized immediately while leaving only dried solids. However, since heated nitrogen gas is blown out from the port 18 at the pressure of about 2-3kg/cm<2>, the dried solids are also removed from the outer wall 14 with ease. Thus, it is enabled to carry out trap cleaning operation effectively and to minimize degradation of rotary pump oil due to gases produced from adhesive substances sticked and accumulated at the bottom of the trap body 1. Resultantly, the quality of etching can be improved. |
