Patent attributes
In preferred embodiments, the invention provides a gas filter for a reactive gas used in semiconductor processing tools and processes that are sensitive to molecular contamination. The reactive gas filter of the invention have improved pressure drop and can supply an output gas stream having concentrations of less than about 1 ppbv for both ammonia and sulfur dioxide for an input gas stream with ammonia and sulfur dioxide concentrations, respectively, of no greater than about 10 ppbv and 5 ppbv. In one aspect the invention provides a reactive gas filter with an improved pressure drop that can supply an output gas stream having concentrations of less than about 1 ppbv for both ammonia and sulfur dioxide for an input gas stream with ammonia and sulfur dioxide concentrations, respectively, of no greater than about 10 ppbv and 5 ppbv, using a filter media volume of no greater than about 0.5 liters.
