Method for polishing substrate

Abstract

In a method for polishing a substrate, a substrate placed on a polishing pad bonded onto a platen is polished while the temperature of a surface of the polishing pad is monitored. An index of the amount of the substrate polished is calculated based on the monitored temperature of the polishing pad surface. When the calculated index of the amount of the substrate polished is below a previously set value, the substrate is detected as an abnormally polished substrate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. §119 on Patent Application No. 2004-272852 filed in Japan on Sep. 21, 2004, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] (1) Field of the Invention [0003] The present invention relates to a substrate polishing method in which a substrate is polished while the temperature of a surface of a polishing pad is measured. [0004] (2) Description of Related Art [0005] In a known chemical mechanical polishing (CMP) technique in which a surface of a semiconductor wafer is polished, semiconductor wafers to be polished are subjected one after another to a polishing process and the polishing process is repeated at regular intervals. Even when trouble with equipment or variations of the time during which a semiconductor wafer is transferred make the interval between one polishing process and the next polishing process longer than usual, the next p...

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Benefits of technology

[0010] The present invention has been made to solve the aforementioned problems, and an object of the present invention is to allow reliable elimination of a substrate that has been insufficiently polished in a substrate polishing process.

[0013] According to the substrate polishing method of the first aspect, information concerning the amount of the substrate polished can be easily obtained. Since an abnormality in the amount of the substrate polished can therefore be detected immediately after the polishing of the substrate, this makes it possible to remove a substrate having such an abnormality that part of the substrate is unpolished from a fabrication process.

[0024] According to the method of the third aspect, the abnormally polished substrate can be easily detected. This can prevent, with reliability, a substrate having such an abnormality that part of the substrate is unpolished from being transferred to later process steps.

Problems solved by technology

The utilization of the point of change of the temperature of the polishing pad surface as an end point of polishing is effective at polishing a metal film to form a buried interconnect but impossible in a polishing process in which a single metal film is to be polished, such as a polishing process for an insulating film.

Meanwhile, when the time interval between one polishing process and the next polishing process becomes longer than usual due to troubles with equipment and the transfer of semiconductor wafers, the temperature of a surface of a polishing pad at the start of the next process becomes lower than usual.

Thus, when polishing is started under the condition that the temperature of the polishing pad surface is low, the polishing rate becomes low.

Therefore, even when polishing is carried out for a normally set time, such an abnormality that part of a substrate is unpolished occurs in a product to be processed.

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