Patent ID: 8557132
Filing Date: 2013-10-15
Classification: B08B,B24B,H01L

Abstract:
1. A method of cleaning a CMP pad, the method comprising: providing a CMP pad that has been used in a CMP process; (i) moving a cleaning pad relative the CMP pad so as to clean the CMP pad; (ii) providing a cleaning fluid to an interface between the cleaning pad and the CMP pad wherein the fluid is selected so as to facilitate cleaning of the CMP pad; (iii) evaluating, substantially parallel to the surface of the cleaning pad, an optical characteristic of the cleaning fluid in the interface during the relative motion of the cleaning pad and the CMP pad and during cleaning of the CMP pad after the cleaning fluid has been provided to the interface to determine a fluid characteristic value that is indicative of the condition of the CMP pad to thereby evaluate the cleanliness of pad, wherein evaluating the optical characteristic comprises projecting a beam of light from a side of the cleaning pad and through the cleaning fluid along the surface of the cleaning pad and detecting from a side of the cleaning pad the beam of light to directly measure a change in refraction of the beam of light due to a change in concentration of contaminants in the cleaning fluid; (iv) repeating (i), (ii), (iii) until the fluid characteristic value corresponds to at least one preselected endpoint values for the cleanliness of the pad to thereby obtain a desired level of cleanliness of the pad; and (v) halting the cleaning pad motion relative to the CMP pad when the at least one preselected endpoint value has been detected.