| 摘要 |
Provided is a method for cleaning a photomask-related substrate, the method in which, when a photomask-related substrate contaminated by a sulfate ion, the photomask-related substrate being selected from a substrate for a photomask, a photomask blank, a photomask, and a production intermediate thereof, is cleaned with pure water, a deaerating step of removing dissolved gas by deaeration is performed in advance on the pure water used for cleaning. Moreover, provided is a method for cleaning a substrate to be cleaned by supplying a cleaning fluid to a cleaning apparatus, the method in which, when the substrate to be cleaned is cleaned by filtering the cleaning fluid with a filter for removing foreign matter and supplying the filtered cleaning fluid to the cleaning apparatus through a supply pipe, at least, prior to a supply of the filtered cleaning fluid to the cleaning apparatus, the filtered cleaning fluid is discharged to the outside of a system through a discharge pipe, and then the filtered cleaning fluid is supplied to the cleaning apparatus through the supply pipe. As a result, provided is a cleaning method that can increase cleaning efficiency for a sulfate ion in a simple and easy way and can reduce the generation of minute foreign matter extremely when, in particular, a photomask-related substrate selected from a substrate for a photomask, a photomask blank, a photomask, and a production intermediate thereof is cleaned. |
