| 摘要 |
PURPOSE:To protect a semiconductor wafer from breaking and contamination by a method wherein carbonic acid or ammonia water solution is added and the electricity specific resistance value of superpure water is specified. CONSTITUTION:Carbonic acid gas or ammonia gas is flowed in a vapor-liquid mixer 4 through a connecting pipe 3 and a branch pipe 9 from a bomb 1, and at the same time, superpure water for dissolution also is flowed on the vapor-liquid mixer 4 through a superpure water pipe 5, and the superpure water for dissolution and the carbonic gas or ammonia gas are contact-mixed in the vapor-liquid mixer 4. The mixed solution is flowed in a water solution storage tank 2 as carbonic acid or ammonia water solution and is stored therein. If it was confirmed by a liquid-level indicator 21 provided with the water solution storage tank 2 that the carbonic acid or ammonia water solution has risen up to an arbitrary water surface, valves 14, 12 and 13 are successively turned off, in case of carbonic acid gas, and after that, a valve 17 provided with an air venting pipe 8 is turned off, and at the same time, a valve 11 is turned on. At this time, the pressure of the carbonic acid gas is applied into the water solution storage tank 2 by the regulated pressure through a reducing valve 10, thereby enabling to lessen the control errors for the installation of an electricity specific resistance meter 19 provided with a superpure water pipe 18 for washing. |
