Abstract: A silicon wafer after being cleaned by using a cleaning liquid is rinsed by using carbonic water. According to such a silicon wafer cleaning method, generation of static due to a rinsing treatment is not caused, so that an electrostatic breakdown is not caused, adhesion of dirt to a cleaned silicon wafer surface due to the static is not caused, adhesion of metal impurities can be prevented in the rinsing treatment of the silicon wafer and, while giving consideration to the cost, furthermore, a rinsing treatment using a clean rinsing liquid free from causing any residue can be performed.

Abstract: A silicon wafer after being cleaned by using a cleaning liquid is rinsed by using carbonic water. According to such a silicon wafer cleaning method, generation of static due to a rinsing treatment is not caused, so that an electrostatic breakdown is not caused, adhesion of dirt to a cleaned silicon wafer surface due to the static is not caused, adhesion of metal impurities can be prevented in the rinsing treatment of the silicon wafer and, while giving consideration to the cost, furthermore, a rinsing treatment using a clean rinsing liquid free from causing any residue can be performed.

Abstract: An ultrapure water production plant that can produce ultrapure water with an extremely low rate of impurity concentration such as dissolved oxygen concentration, etc., is provided. A primary pure water is introduced and a catalyst mixed tower 4, wherein catalyst supports strong base anion exchange resins are mixed and filled, is located in the downstream of the ultraviolet oxidation equipment of the ultrapure water production plant 1 producing ultrapure water. Further in the latter part of the catalyst mixed tower 4, membrane degasser 5 and demineralization equipment 6 are located. Hydrogen peroxide generated in the ultraviolet oxidation equipment 3 etc., is decomposed by contacting the catalyst supports filled in the catalyst mixed tower 4 and thus decomposition of the strong base anion exchange resins is inhibited.