Polishing method and polishing apparatus
A polishing method and a polishing apparatus which can increase a polishing rate and can control a polishing profile of a substrate being polished by adjusting a surface temperature of a polishing pad are disclosed. The polishing method for polishing a substrate by pressing the substrate against a polishing pad on a polishing table includes a pad temperature adjustment step of adjusting a surface temperature of the polishing pad, and a polishing step of polishing the substrate by pressing the substrate against the polishing pad having the adjusted surface temperature. In the pad temperature adjustment step, the surface temperature of a part of an area of the polishing pad, the area being to be brought in contact with the substrate, is adjusted during the polishing step so that the rate of temperature change of a temperature profile in a radial direction of the surface of the polishing pad becomes constant in the radial direction of the polishing pad.
1. A polishing method for polishing a substrate by pressing the substrate against a polishing pad on a polishing table, comprising:
preparing a pad contact member configured to contact a surface of the polishing pad for adjusting a surface temperature of the polishing pad;
determining a temperature distribution in a radial direction of the surface of the polishing pad when the substrate is polished under such polishing conditions as to achieve a target polishing profile in a state where the surface temperature of the polishing pad is not adjusted, the determined temperature distribution being set as a reference temperature distribution:
adjusting the surface temperature of the polishing pad by using the pad contact member configured to contact the surface of the polishing pad; and
polishing the substrate by pressing the substrate against the polishing pad while the surface temperature of the polishing pad is adjusted;
wherein the surface temperature of a part of the polishing pad is adjusted by the pad contact member during polishing of the substrate so that the rate of temperature increase of respective points in the temperature distribution in the radial direction of the surface of the polishing pad becomes constant in the radial direction of the polishing pad with respect to the reference temperature distribution.
2. The polishing method according to claim 1 , wherein the rate of temperature increase is calculated for each of temperature measurement points on the polishing pad.
3. The polishing method according to claim 1 , wherein the temperature distribution is prepared by defining a plurality of areas in the radial direction of the polishing pad, providing at least one temperature measurement point in each of the plurality of areas, and using measured values measured at the temperature measurement points.
4. The polishing method according to claim 1 , wherein the temperature distribution is prepared by defining a plurality of areas in the radial direction of the polishing pad, providing a plurality of temperature measurement points in each of the plurality of areas, the measured values measured at the plural temperature measurement points are used individually or an average value of the measured values is used.
5. The polishing method according to claim 1 , wherein the part of the polishing pad whose surface temperature is adjusted is variable during polishing of the substrate depending on the rate of temperature increase.
6. The polishing method according to claim 1 , wherein the temperature measurement of the polishing pad is performed by a thermograph or a radiation thermometer.
7. The polishing method according to claim 1 , wherein the part of the polishing pad whose surface temperature is adjusted is at least one of a plurality of concentric annular areas defined in the radial direction of the polishing pad which is rotated.
8. The polishing method according to claim 1 , wherein the pad contact member is moved in the radial direction of the polishing pad to change the area of the polishing pad whose surface temperature is adjusted during polishing of the substrate so that the rate of temperature increase becomes constant in the radial direction of the polishing pad.