Method of polishing wafer and wafer polishing apparatus
AssigneeSumco Corporation
InventorTomonori Kawasaki
Life of this patent
Estimating the term…
Abstract
A practical method of polishing a wafer that can reduce wafer loss due to dummy polishing, and stabilize the LPD count in production wafers at a low level, is provided. In the method of polishing a wafer according to the present disclosure, a wafer 104 is brought into contact with a polishing cloth 112 provided on the surface of a polishing plate 110, and the wafer 104 and the polishing plate 110 are rotated, thereby performing several rounds of a polishing process on the surface of the wafer 104 using the same polishing cloth 112. At this time, the contact angle of the polishing cloth is measured, and based on the measured value thereof, the timing for a switchover from an initial polishing (or a dummy polishing) mode to a production polishing mode is determined.
Claims8
A method of polishing a wafer, the method comprising:
- polishing at least one initial wafer in an initial polishing mode to obtain at least one polished initial wafer that is not used as a product;
- measuring a contact angle of a drop of water supplied onto a polishing cloth after the polishing of the at least one initial wafer;
- determining, based on the measured contact angle, a timing for a switchover from the initial polishing mode to a production polishing mode;
- and
- polishing the at least one production wafer in the production polishing mode after the initial polishing mode to obtain at least one polished production wafer that is used as a product.
A wafer polishing apparatus comprising:
- a measuring device that measures a contact angle of a drop of water supplied onto a polishing cloth;
- and
- a controller that, based on a measured contact angle value obtained from the measuring device, determines a timing for a switchover from an initial polishing mode in which at least one initial wafer is polished to obtain at least one polished initial wafer that is not used as a product, to a production polishing mode in which at least one production wafer is polished to obtain at least one polished production wafer that is used as a product.
Dependencies are inferred from the claim text.