| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a phosphoric acid regeneration method in which a phosphoric acid solution can be regenerated reliably by a simple apparatus configuration, and to provide a phosphoric acid regeneration apparatus, and a substrate processing system using the phosphoric acid regeneration apparatus. <P>SOLUTION: A heated phosphoric acid solution is stored in an immersion processing bath 20 of an immersion processing apparatus 2, and a substrate W on which a silicon nitride film is formed is immersed therein thus performing the etching. The phosphoric acid solution used for etching repeatedly and having an increased silicon concentration is transported from the immersion processing apparatus 2 to a storage tank 50 of a phosphoric acid regeneration apparatus 5 and stored therein. The phosphoric acid solution after use in the storage tank 50 is cooled slowly, and impurities containing a silicon oxide are precipitated and grow into particles of comparatively large size. When the phosphoric acid solution in which the impurities are precipitated passes through a filter 51, the impurities adhere to the filter 51 and are removed thus regenerating the phosphoric acid solution. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
