Electrostatic chuck with external flow adjustments for improved temperature distribution

Patent metadata

Field	Value
Publication number	US-10121688-B2
Application number	US-201715481183-A
Country	US
Kind code	B2
Filing date	Apr 6, 2017
Priority date	Dec 31, 2013
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

An electrostatic chuck is described with external flow adjustments for improved temperature distribution. In one example, a method for adjusting coolant flow in an electrostatic chuck includes heating a dielectric puck, the dielectric puck being for electrostatically gripping a silicon wafer. Heat is detected at a plurality of locations on a top surface of the dielectric puck, the locations each being thermally coupled to at least one of a plurality of coolant chambers of the electrostatic chuck. A plurality of valves are adjusted to control coolant flow into the coolant chambers based on the detected heat.

First claim

What is claimed is:

1. A method for adjusting coolant flow in an electrostatic chuck, the method comprising:
heating a dielectric puck, the dielectric puck being for electrostatically gripping a silicon wafer;
detecting heat at a plurality of locations on a top surf ace of the dielectric puck, the locations each being thermally coupled to at least one of a plurality of coolant chambers of the electrostatic chuck; and
adjusting a plurality of valves to control coolant flow into the coolant chambers based on the detected heat, wherein the plurality of valves is embedded within the electrostatic chuck.

2. The method of claim 1 , wherein detecting heat comprises imaging the dielectric puck during flowing coolant into the coolant chambers through the valves and during applying heat to the dielectric puck.

3. The method of claim 2 , wherein applying heat comprises activating heaters within the electrostatic chuck.

4. The method of claim 1 wherein adjusting a plurality of valves comprises independently rotating valve bodies of each of the plurality of valves to move the valve bodies with respect to a valve seat to control the flow of coolant from a supply plenum to a respective coolant chamber.

5. The method of claim 1 , wherein detecting heat comprises determining a temperature level at different areas of the dielectric puck, the different areas corresponding to different coolant chambers.

6. The method of claim 5 , wherein adjusting the plurality of valves comprises increasing coolant flow to coolant chambers corresponding to hotter areas and decreasing coolant flow to coolant chambers corresponding to cooler areas.

7. The method of claim 1 , wherein adjusting valves comprises driving gear motors of a valve controller, the gear motors each being coupled to a respective one of the valves to individually control coolant flow into each respective coolant chamber.

8. The method of claim 1 , wherein adjusting a plurality of valves comprises adjusting valves between a common supply plenum that receives coolant from an external source and each of the plurality of coolant chambers to control the flow rate of coolant from the supply plenum to the respective cooling zone.

9. The method of claim 1 , wherein the coolant chambers are within a cooling plate fastened to and thermally coupled to the dielectric puck.

10. The method of claim 1 , wherein adjusting a plurality of valves comprises activating a valve controller to engage and independently control each valve to adjust the flow of coolant through each valve by driving a gear motor to adjust the position of a valve body of each respective valve.

11. The method of claim 9 , wherein controlling flow into the coolant chambers comprises controlling flow through a respective plurality of orifices each defined in a middle plate of the cooling plate into respective coolant chambers of the middle plate.

12. The method of claim 11 , wherein the middle plate has hexagonal areas to define the coolant chambers.

13. The method of claim 12 , wherein each hexagonal area is supplied by a different one of the plurality of valves.

14. An apparatus for adjusting coolant flow in an electrostatic chuck, the apparatus comprising:
means for heating a dielectric puck, the dielectric puck being for electrostatically gripping a silicon wafer;
means for detecting heat at a plurality of locations on a top surf ace of the dielectric puck, the locations each being thermally coupled to at least one of a plurality of coolant chambers of the electrostatic chuck; and
means for adjusting a plurality of valves to control coolant flow into the coolant chambers based on the detected heat, wherein the plurality of valves is embedded within the electrostatic chuck.

15. The apparatus of claim 14 , wherein the means for detecting heat comprises an imager to image the dielectric puck during flowing coolant into the coolant chambers through the valves and during applying heat to the dielectric puck.

16. The apparatus of claim 15 , wherein the means for heating comprises resistance heaters activated within the electrostatic chuck.

17. The apparatus of claim 14 wherein the means for adjusting a plurality of valves comprises independently rotatable valve bodies of each of the plurality of valves to move the valve bodies with respect to a valve seat to control the flow of coolant from a supply plenum to a respective coolant chamber.

18. The apparatus of claim 14 , wherein the means for adjusting comprises a processor coupled to the means for detecting heat and to a valve controller to operate a motor of the valve controller to adjust coolant flow based on the detected heat.

19. The method of claim 14 , wherein the means for detecting heat determines a temperature level at different areas of the dielectric puck, the different areas corresponding to different coolant chambers.

20. The method of claim 19 , wherein the means for adjusting the plurality of valves operates by increasing coolant flow to coolant chambers corresponding to hotter areas and decreasing coolant flow to coolant chambers corresponding to cooler areas.

Assignees

• Applied Materials Inc

Inventors

• Busche Matthew J
• Parkhe Vijay D
• Boyd Jr Wendell
• Thach Senh
• Makhratchev Konstantin
• Ono Masanori

Classifications

• H10P72/0434

  mainly by convection · CPC title

• H10P72/0432

  mainly by conduction · CPC title

• H10P72/72

  using electrostatic chucks · CPC title

• H10P72/722 Primary

  Details of electrostatic chucks · CPC title

• H05K7/20218 Primary

  using a liquid coolant without phase change in electronic enclosures (in cabinets of standardized dimensions H05K7/20536; in server cabinets H05K7/20709; in vehicle electronic casings H05K7/20845; in power control electronics H05K7/2089; in displays H05K7/20954) · CPC title