Patent ID: 6739013
Filing Date: 2004-05-25
Classification: B08B,H01L

Abstract:
A wafer cleaning apparatus for cleaning a wafer having two surfaces, comprising:a wafer supporting device for supporting the wafer to be cleaned; sponges for cleaning the wafer, each of said sponges configured in contact with either one of the surfaces of the wafer, said sponges rotatably mounted with rotational axes that are parallel to the wafer; a sponge positioning device for pushing said sponges against the water; a wafer rotation drive adapted to rotate the wafer at a constant speed; a sponge rotation drive system adapted to rotate said sponges at a constant speed; and a closed loop controller receiving respective motor current signals from said wafer rotation drive and said sponge rotation drive system; said closed loop controller providing an adjustment signal to said sponge positioning device, maid adjustment signal for adjusting friction between said sponges and the wafer in response to the motor current signals.