Temperature control in chemical mechanical polish

1. A method comprising:

polishing a wafer on a polishing pad;

performing conditioning on the polishing pad using a disk of a pad conditioner;

detecting a first temperature of the polishing pad; and

in response to the first temperature, selecting a heat-exchange media from a coolant and a heating media, and conducting the heat-exchange media into the disk, wherein the heat-exchange media conducted into the disk has a second temperature different from the first temperature of the polishing pad.

2. The method of claim 1 , wherein the conducting the heat-exchange media comprises conducting a coolant, with the second temperature being lower than the first temperature.

3. The method of claim 1 , wherein the conducting the heat-exchange media comprises conducting a heating media, with the second temperature being higher than the first temperature.

4. The method of claim 1 further comprising:

performing an additional detection to detect a third temperature of the polishing pad, and in response to the third temperature, keeping the disk of the pad conditioner in contact with the polishing pad.

5. The method of claim 1 , wherein the heat-exchange media is conducted into a channel in the disk, and a portion of the channel in the disk has a top-view shape selected from a spiral shape and a zigzag shape.

6. The method of claim 1 , wherein the heat-exchange media comprises a coolant, and the method further comprises:

stopping conducting the coolant; and

conducting a heating media into the pad conditioner.

7. The method of claim 1 further comprising conducting a heat-exchange media into a wafer holder that holds the wafer onto the polishing pad.

8. A method comprising:

polishing a wafer on a polishing pad;

performing conditioning on the polishing pad using a disk of a pad conditioner;

conducting a coolant into and out of the disk, wherein the coolant is configured to lower a top surface temperature of the polishing pad; and

conducting a heating media into and out of the disk, wherein the heating media is configured to raise the top surface temperature of the polishing pad.

9. The method of claim 8 , wherein the coolant is conducted into and out of a first channel of the disk, and the heating media is conducted into and out of a second channel of the disk, and the first channel and the second channel are separate channels.

10. The method of claim 8 , wherein the coolant and the heating media are conducted into and out of a same channel of the disk, and are conducted at different time.

11. The method of claim 8 , wherein the heating media is conducted when no wafer is being polished on the polishing pad, and the coolant is conducted after the wafer starts to be polished.

12. The method of claim 8 , wherein the performing the conditioning on the polishing pad comprises abrading the polishing pad using the pad conditioner to increase a roughness of the polishing pad.

13. The method of claim 8 further comprising:

detecting the top surface temperature of the polishing pad; and

in response to the detected top surface temperature, moving a disk of the polishing pad in contact with the polishing pad away from the polishing pad.

14. The method of claim 8 further comprising conducting an additional coolant into a wafer holder placed on the polishing pad.

15. The method of claim 8 further comprising conducting an additional heating media into a wafer holder placed on the polishing pad.

16. A method comprising:

polishing a wafer on a polishing pad;

performing a first detection to detect a temperature of the polishing pad;

in response to the detected temperature to be higher than a first pre-determined temperature, conducting a coolant into and out of a disk of a pad conditioner, wherein the disk performs conditioning on the polishing pad when the coolant is conducted; and

in response to the detected temperature to be lower than a second pre-determined temperature, conducting a heating media into and out of the disk, wherein the disk performs conditioning on the polishing pad when the heating media is conducted.

17. The method of claim 16 further comprising, in response to the detected temperature to be lower than the first pre-determined temperature and higher than the second pre-determined temperature, moving a disk of the pad conditioner away from the polishing pad.

18. The method of claim 16 , wherein when the coolant or the heating media is conducted, the wafer is being polished.

19. The method of claim 16 , further comprising conducting an additional coolant into a wafer holder placed on the polishing pad.

20. The method of claim 1 , wherein the heat-exchange media comprises a liquid.