Patent ID: 6946036

Claim:
A method for removing particles on semiconductor wafers, wherein the semiconductor wafers are bare wafers or wafers having a silicon oxide film, comprising the steps of: forming an oxide film at least 2.5 Angstroms thick on a surface of a semiconductor wafer while performing a first cleaning process in which semiconductor wafers are cleaned for a prescribed time by immersing them in a first cleaning solution consisting of ultra-pure water containing a prescribed quantity of ozone in a first cleaning tank, wherein the prescribed time in the first cleaning process is in the range of 3 to 20 minutes; and performing a second cleaning process in which said semiconductor wafers are cleaned for a prescribed time by immersing them in a second cleaning solution consisting of ultra-pure water containing 0.3 ppm to 0.4 ppm of hydrogen in a second cleaning tank, wherein ultrasonic waves are supplied to said second cleaning solution in said second process.