MEASURING THE SURFACE PROPERTIES OF POLISHING PADS USING ULTRASONIC REFLECTANCE

摘要

The present invention provides a system and method for measuring the surface properties of polishing pads using non-contact ultrasonic reflectance. An ultrasonic probe (15) is located over the polishing surface (120) and configured to both transmit an ultrasonic signal to the polishing surface (110) and receive a modified ultrasonic signal from the polishing surface without contacting the polishing surface. A subsystem coupled to the ultrasonic probe is configured to determine a surface property of the polishing (105) pad from the modified signal.