ELECTROSTATIC CHUCK SYSTEM AND PROCESS FOR RADIALLY TUNING THE TEMPERATURE PROFILE ACROSS THE SURFACE OF A SUBSTRATE

• US 20100193501A1
• Filed: 01/29/2010
• Published: 08/05/2010
• Est. Priority Date: 02/04/2009
• Status: Active Grant

• Current Assignee: Mattson Technology, Inc. (Beijing Economic & Technology Development Area), BeiJing E-Town Semiconductor Technology Co., Ltd.
• Original Assignee: Mattson Technology, Inc. (Beijing Economic & Technology Development Area)
• Inventors: Devine, Daniel J., Zucker, Martin L., Lee, Young Jai
• Granted Patent: US 8,405,005 B2
• Time in Patent Office: Days
• US Class Current: 219/443.1
• CPC Class Codes: H01L 21/67248 Temperature monitoring
• CPC Class Codes: H01L 21/6831 using electrostatic chucks
• CPC Class Codes: H02N 1/08 with conductive charge carrier, i.e. capacitor machines

Abstract

An electrostatic chuck system for maintaining a desired temperature profile across the surface of the substrate is disclosed. The electrostatic chuck system includes a pedestal support defining a substantially uniform temperature profile across the surface of the pedestal support and an electrostatic chuck supported by the pedestal support. The electrostatic chuck has a clamping electrode and a plurality of independently controlled heating electrodes. The independently controlled heating electrodes include an inner heating electrode defining an inner heating zone and a peripheral heating electrode defining a peripheral heating zone separated by a gap distance. The temperature profile across the surface of the substrate can be tuned by varying thermal characteristics of the pedestal thermal zone, the inner heating zone, the peripheral heating zone, or by varying the size of the gap distance between the inner heating electrode and the peripheral heating electrode.

Claims

1. A system for adjusting a temperature profile across the surface of a substrate, comprising:

a pedestal support comprising a pedestal thermal control system adapted to provide a pedestal thermal zone, the pedestal thermal zone defining a substantially uniform temperature profile across the surface of the pedestal support, the pedestal thermal zone having thermal characteristics based on the output of the pedestal thermal control system;

an electrostatic chuck supported by the pedestal support, the electrostatic chuck comprising a clamping electrode and a plurality of heating electrodes, the heating electrodes comprising an inner heating electrode and a peripheral heating electrode separated by a gap distance, the inner heating electrode defining an inner heating zone having thermal characteristics based on the output of the inner heating electrode, the peripheral heating electrode defining a peripheral heating zone having thermal characteristics based on the output of the peripheral heating electrode; and

a control system adapted to adjust the temperature profile across the surface of the substrate by varying at least one of the output of the pedestal thermal control system, inner heating electrode, or peripheral heating electrode.

2. The system of claim 1, wherein the control system is adapted to adjust the temperature gradient between the inner heating zone and the peripheral heating zone by varying at least one of the output of the pedestal thermal control system, inner heating electrode, or peripheral heating electrode.

3. The system of claim 1, wherein the clamping electrode is a monopolar electrode.

4. The system of claim 1, wherein the clamping electrode is a bipolar electrode.

5. The system of claim 1, wherein the electrostatic chuck comprises aluminum oxide.

6. The system of claim 1, wherein the pedestal thermal control system comprises a fluid flow channel for circulating a thermal exchange fluid.

7. The system of claim 6, wherein the pedestal thermal control system comprises an inner fluid flow channel and a peripheral fluid flow channel, the inner fluid flow channel and peripheral fluid flow channel being controlled to provide a substantially uniform temperature profile across the surface of the pedestal support.

8. The system of claim 1, wherein the top surface of the electrostatic chuck comprises a raised peripheral seal ring and a plurality of mesas having a height approximately equal to the height of the raised peripheral seal ring.

9. The system of claim 1, wherein the electrostatic chuck comprises at least one additional heating electrode between the inner heating electrode and the peripheral heating electrode, the controller being adapted to adjust the size of the gap distance between the inner heating electrode and the peripheral heating electrode by energizing the at least one additional heating electrode.

10. The system of claim 9, wherein the controller is adapted to adjust the temperature gradient between the inner heating zone and the peripheral heating zone by varying the size of the gap distance between the inner heating electrode and the peripheral heating electrode.

11. The system of claim 1, wherein the gap distance has a size sufficient to create a temperature gradient between the peripheral heating zone and the inner heating zone, the temperature gradient having a value of at least approximately 6°

C./cm when the temperature of the peripheral heating zone is maintained approximately 28.5°

C. higher than the temperature of the inner heating zone.

12. A system for maintaining a temperature profile across the surface of a substrate during processing, the system comprising:

a pedestal defining a substantially uniform temperature profile across the surface of the pedestal;

an electrostatic chuck comprising a clamping electrode and a plurality of heating electrodes, the heating electrodes comprising an inner heating electrode defining an inner heating zone and a peripheral heating electrode defining a peripheral heating zone;

wherein the inner heating electrode and the peripheral heating electrode are separated by a gap distance having a size sufficient to create a temperature gradient between the peripheral heating zone and the inner heating zone, the temperature gradient being at least 6°

C./cm when the temperature of the peripheral heating zone is maintained approximately 28.5°

C. higher than the temperature of the inner heating zone.

13. The system of claim 12, wherein the gap distance has a size sufficient to cause the temperature gradient between the inner heating zone and peripheral heating zone to be at least approximately 8°

C./cm when the temperature of the peripheral heating zone is maintained approximately 28.5°

C. higher than the temperature of the inner heating zone.

14. The system of claim 12, wherein the size of the gap distance is from approximately 15 mm to approximately 35 mm.

15. The system of claim 12, wherein the size of the gap distance is approximately 20 mm.

16. A process for radially tuning the temperature profile across the surface of a substrate, the process comprising:

placing a substrate on an electrostatic chuck assembly comprising an electrostatic chuck supported by a pedestal, the electrostatic chuck comprising a clamping electrode and an inner heating electrode defining an inner heating zone and a peripheral heating electrode defining a peripheral heating zone, the inner heating electrode and the peripheral heating electrode being separated by a gap distance;

clamping the substrate on the electrostatic chuck assembly by energizing the clamping electrode;

adjusting the temperature gradient between the inner heating zone and the peripheral heating zone by adjusting the size of the gap distance between the inner heating electrode and the peripheral heating electrode.

17. The process of claim 16, wherein the size of the gap distance is adjusted by energizing an additional heating electrode located between the inner heating electrode and the peripheral heating electrode.

18. The process of claim 16, wherein the process further comprises adjusting the temperature gradient between the inner heating zone and the peripheral heating zone by varying the power supplied to the inner heating electrode or the peripheral heating electrode.

19. The process of claim 18, wherein the process further comprises circulating a heat transfer fluid through the pedestal.

20. The process of claim 19, wherein the process further comprises adjusting the temperature gradient between the inner heating zone and the peripheral heating zone by regulating the heat transfer fluid flowing through the pedestal.