TREATMENT OF EXHAUST GAS IN DRY ETCHING OF GALLIUM-ARSENIDE WAFER

摘要

PURPOSE:To reduce maintenance operation and to facilitate removal of harmful substance contained in exhaust gas by providing a mechanism for preventing deposition of chloride and fluoride of Ga and As to a vacuum pump and passing the exhaust of the vacuum pump through an adsorbent. CONSTITUTION:A casing 5a is provided to an oil-sealed rotary pump or a dry vacuum pump 5 of the exhaust system 6 of a dry etching chamber 1 and both a line 12 for introducing a purging gas and a discharge line 12a are connected and the pump 5 is held in the atmosphere of inert gas 11 and furthermore a heating mechanism is provided and thereby a mechanism 10 for preventing deposition of chloride and fluoride of Ga and As is constituted. An adsorption tower 9 packed with an adsorbent 8 such as activated carbon is provided to the outlet line 7 of the exhaust system 6 and harmful substance such as chloride and fluoride of Ga and As is adsorbed and removed.