Patent ID: 7507296

Claim:
A method monitoring brush position comprising: providing a brush having a first end and a second end; storing first data indicative of a position of the first end of the brush when the brush is in contact with a wafer during a scrubbing operation; storing second data indicative of a position of the second end of the brush when the brush is in contact with the wafer during the scrubbing operation; adjusting a position of a first limit sensor associated with the first end of the brush to achieve a desired first brush end position; adjusting a position of a second limit sensor associated with the second end of the brush to achieve a desired second brush end position; applying a first pressure to the wafer with the first end of the brush based on the position of the first end of the brush; and applying a second pressure to the wafer with the second end of the brush based on the position of the second end of the brush.