摘要 |
In order to remove a deposit adhered to the backside of the peripheral portion of a wafer, a cleaning gas containing carbon dioxide gas is set to a pressure that is slightly lower than the pressure corresponding to a vapor pressure line of carbon dioxide at a temperature in the nozzle, and a gas cluster of carbon dioxide is generated. A gas cluster of carbon dioxide generated under such a condition is in a state immediately prior to undergoing a phase change to a liquid and therefore is a gas cluster having a large cluster diameter and having molecules that are firmly solidified. |