摘要 |
A valve is closed while a cleaning liquid is fed into a tubular body of a cleaning nozzle, and a piezoelectric element applies vibrations to the cleaning liquid. This causes droplets of the cleaning liquid to be produced and discharged from a plurality of discharge holes. The droplet diameter of the discharged droplets is in the range from 15 to 200μm, and the distribution of the droplet diameter is such that the value of where a value of 3σdoes not exceed 10% of the average droplet diameter. The droplet speed is in the range from 20 to 100 meters per second, and the distribution of the droplet speed is such that the value of where a value of 3σdoes not exceed 10% of the average droplet speed. The droplet flow rate is not less than 10 milliliters per minute. Discharging the droplets of the cleaning liquid from the cleaning nozzle toward a substrate while satisfying these discharge conditions improves cleaning efficiency without damages to the substrate. |