| 摘要 |
PROBLEM TO BE SOLVED: To uniformly and stably clean a substrate, to save resources, and to reduce waste. SOLUTION: When the substrate is cleaned by using an ammonium fluoride aqueous solution or a mixed solution of an ammonium fluoride aqueous solution and hydrofluoric acid as a cleaning liquid, with the passage of time during the use of the cleaning liquid, the cleaning liquid is added with at least one selected from water, ammonia, ammonia water, and an ammonium fluoride aqueous solution. A necessary amount of the additives corresponding to the passage of time is calculated on the basis of measured data to control the cleaning liquid. Alternatively, the component concentrations during cleaning are calculated, and the additives can be supplied corresponding to the obtained results. |
