Measuring the surface properties of polishing pads using ultrasonic reflectance
AssigneePsiloQuest, Inc.
InventorYaw S. Obeng
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Abstract
The present invention provides a system and method for measuring the surface properties of polishing pads using non-contact ultrasonic reflectance. An ultrasonic probe is located over the polishing surface and configured to both transmit an ultrasonic signal to the polishing surface 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 pad from the modified signal.
Claims21
A system for measuring surface properties of a polishing pad comprising:
- a polishing pad having a polishing surface associated therewith;
- an ultrasonic probe located over said polishing surface and configured to both transmit an ultrasonic signal to said polishing surface and receive a modified ultrasonic signal from said polishing surface without contacting said polishing surface;
- and
- a subsystem coupled to said ultrasonic probe and configured to determine a surface property of said polishing pad from said reflection.
A method for measuring the surface properties of a polishing pad, comprising:
- situating an ultrasonic probe above a polishing surface of a polishing pad, without contacting said polishing surface;
- transmitting an ultrasonic signal from said probe to said polishing surface, said ultrasonic signal being modified by said polishing surface;
- and
- receiving said modified signal by said ultrasonic probe.
Dependencies are inferred from the claim text.