Process and equipment for treating a gas containing impurities in which the gas is submitted at atmospheric pressure to a radiofrequency inductive plasma discharge

摘要

Process and equipment for treating a gas containing impurities in which the gas is submitted at atmospheric pressure to a radiofrequency inductive plasma discharge. The discharge operates a double walled silica glass torch, with circulation of a cooling liquid between the two walls, a refractory material torch such as a ceramic or alumina torch, or a metal torch. The coupling to the discharge is an inductive transverse electric coupling (TE) called an "H", or a magnetic transverse coupling called an "E" or a mixture of "H" and "E". The discharge is produced at a frequency of between 50 kHz and 200MHz, in a tube with an internal diameter of between 5 or 10mm and 50 or 150mm. The discharge operates a silica glass torch, which is double walled with circulation of a cooling liquid between the two walls and has a power of between 1 and 1000kW. Alternatively, the discharge operates a refractory material torch such as a ceramic or alumina torch, or a metal torch. The gas treated is a rare gas containing a perfluorided (PFC) or hydrocarbonated or hydrofluorocarbonated (HFC) gas. The discharge has at least one zone with a temperature greater than 5000K. Oxygen and/or water is added. The flow of gas treated is between 0.2 and 25 m 3/h. The gas treated contains gaseous effluents from a production or growth or engraving or cleaning process or semi-conductor treatment or thin layer semiconductor or conductor or dielectric or substrate process. The gas treated contains gaseous effluents from a production or growth or engraving or cleaning or treatment process for thin layers of silicon, in particular production of screens. The system includes a reactive element to react with the components from the plasma treatment to destroy them. An independent claim is made for a reaction chamber producing a perfluorided or hydrofluorocarbonated gas with a treatment system as described above attached to it.