Deposition mask cleaning apparatus and deposition mask cleaning method

A deposition mask cleaning apparatus comprising:

• a treated water bath containing treated water in which a deposition mask is immersed, the treated water bath comprising a treatment bath containing the treated water, an outer bath disposed above a bottom of the treatment bath, and a cover covering an upper part of the outer bath;
• a treated water generation device fluidly connected to the treated water bath to provide treated water, the treated water contacting the deposition mask comprising at least one of ozone water, hydrogen water, ammonia hydrogen water, and carbonated water;
• a treated water supply pipe connecting the treatment bath and the treated water generation device,
• an outer bath outlet pipe connected to the outer bath and configured to discharge the treated water from the outer bath;
• a treatment gas outlet pipe connected to the outer bath and configured to discharge a gas discharged from the treatment bath to a space defined by the outer bath and the cover;
• a level sensor disposed in the treated water bath and configured to measure the level of the treated water based on a sensed level of the treated water in the treated water bath;
• a bubble generation device disposed in the treated water supply pipe to provide bubbles in the treated water;
• and
• a controller that regulates the level of the treated water in the treated water bath via the level sensor and a control valve, the controller further regulating the size and quantity of bubbles formed via the bubble generation device such that bubbles that contact the deposition mask and clean a portion of foreign matter from the deposition mask comprise both microbubbles having a bubble diameter of about 50 μm to 1 μm and nanobubbles having a bubble diameter of less than 1 μm, wherein
• the bubble generation device comprises a bubble size varying device connected to the controller, and
• the treated water bath includes a spray part that faces the deposition mask and is configured to spray treated water onto the deposition mask while the deposition mask is within the treatment bath but not immersed in liquid.