Dust removing apparatus and dust removing method

摘要

A dust removing apparatus equipped with a back washing mechanism and a dust removing method for removing solid silica fine powder contained in a gas discharged from a semiconductor producing step of a single-wafer processing atmospheric pressure CVD apparatus without causing problems caused by the increase of a pressure loss and by a pressure fluctuation, wherein filter elements each having a ratio of a surface area of a primary side of a filter membrane to an apparent external surface area of the filter element of from 1 to 5 is used, gas jetting nozzle(s) for back washing is formed in the secondary side of the filter element, back washing is not carried out during filtration in the filter element and at or after changing the processing of a wafer in the CVD apparatus, back washing is carried out to blow down the silica fine powder accumulated on the primary side of the filter membrane.