Patent attributes
A method for controlling damages in cleaning a semiconductor wafer comprising features of patterned structures, the method comprising: delivering a cleaning liquid over a surface of a semiconductor wafer during a cleaning process; and imparting sonic energy to the cleaning liquid from a sonic transducer during the cleaning process, wherein power is alternately supplied to the sonic transducer at a first frequency and a first power level for a first predetermined period of time and at a second frequency and a second power level for a second predetermined period of time, the first predetermined period of time and the second predetermined period of time consecutively following one another, wherein at least one of the cleaning parameters is determined such that a percentage of damaged features as a result of the imparting sonic energy is lower than a predetermined threshold.