In-situ real-time monitoring technique and apparatus for detection of thin films during chemical/mechanical polishing planarization
First Claim
1. A chemical mechanical polisher for planarizing a film on one side of a substrate having two sides, the polisher comprising:
- a rotatable platen configured to receive a polishing pad;
a light source;
a first optical fiber to transmit light from the light source and direct the light through the platen toward the substrate from the side of the substrate with the one film to illuminate at least one section on the film;
a second optical fiber to receive light reflected off the illuminated section of the film and direct the light through the platen;
a photodetector to receive the reflected light from the second optical fiber a computer system coupled to the photodetector and operable to monitor a dimensional change of the film based on the reflected light from the film on the substrate.
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Accused Products
Abstract
A technique and apparatus is disclosed for the optical monitoring and measurement of a thin film (or small region on a surface) undergoing thickness and other changes while it is rotating. An optical signal is routed from the monitored area through the axis of rotation and decoupled from the monitored rotating area. The signal can then be analyzed to determine an endpoint to the planarization process. The invention utilizes interferometric and spectrophotometric optical measurement techniques for the in situ, real-time endpoint control of chemical-mechanical polishing planarization in the fabrication of semiconductor or various optical devices. The apparatus utilizes a bifurcated fiber optic cable to monitor changes on the surface of the thin film.
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Citations
17 Claims
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1. A chemical mechanical polisher for planarizing a film on one side of a substrate having two sides, the polisher comprising:
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a rotatable platen configured to receive a polishing pad;
a light source;
a first optical fiber to transmit light from the light source and direct the light through the platen toward the substrate from the side of the substrate with the one film to illuminate at least one section on the film;
a second optical fiber to receive light reflected off the illuminated section of the film and direct the light through the platen;
a photodetector to receive the reflected light from the second optical fiber a computer system coupled to the photodetector and operable to monitor a dimensional change of the film based on the reflected light from the film on the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification