Method and apparatus for compensating non-uniform wafer processing in plasma processing chamber

• US 6,188,564 B1
• Filed: 03/31/1999
• Issued: 02/13/2001
• Est. Priority Date: 03/31/1999
• Status: Expired due to Term

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Hao, Fangli J.
• Primary Examiner(s): SHERRY, MICHAEL JUDE
• Application Number:
  US09/282,644
• Time in Patent Office: 685 Days
• Field of Search: 361/230-234, 279/128
• US Class Current: 361/234
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

A method and apparatus for compensating non-uniform wafer processing in a plasma processing chamber. The plasma processing chamber has an electrostatic chuck for clamping a wafer. The electrostatic chuck has one or more layers. A first wafer is processed on an electrostatic chuck in a first plasma processing chamber by exposing the first wafer to a plasma. Then, non-uniformity characteristics of the processed first wafer are determined. Based on the non-uniformity characteristics, one or more layers of the electrostatic chuck are configured to substantially compensate for the non-uniformity characteristics. A second wafer is then processed on the configured electrostatic chuck to produce substantially uniform process results.

Claims

1. A method for compensating non-uniform wafer processing in a plasma processing chamber having an electrostatic chuck for clamping a wafer, said electrostatic chuck having a plurality of layers, the method comprising:

processing a first wafer on an electrostatic chuck in a first plasma processing chamber, said first wafer being exposed to a plasma in said first plasma processing chamber;

determining non-uniformity characteristics of said processed first wafer;

configuring one or more layers of said electrostatic chuck to substantially compensate for said non-uniformity characteristics on said first wafer; and

processing a second wafer on said configured electrostatic chuck.

2. The method as recited in claim 1, wherein said non-uniformity characteristics of said processed first wafer is determined by measuring said processed first wafer at a plurality of radial positions.

3. The method as recited in claim 2, wherein said non-uniformity characteristics is generated by obtaining a uniformity curve showing a relationship between said processed first wafer and said radial positions.

4. The method as recited in claim 1, wherein a specified layer among said one or more layers is partitioned into a plurality of electrically isolated portions.

5. The method as recited in claim 4, wherein said specified layer is arranged in a shape of varying thickness characterized by varying impedance, wherein said varying impedance is capable of producing varying DC bias on said wafers such that said non-uniformity characteristics are substantially compensated.

6. The method as recited in claim 4, wherein each of said partitioned portions are formed of different materials having different impedance characteristics capable of producing varying DC bias on said wafers such that said non-uniformity characteristics are substantially compensated.

7. The method as recited in claim 5, wherein said partitioned portions are formed of a same material.

8. The method as recited in claim 5, wherein said shape is a stair-step.

9. The method as recited in claim 5, wherein said shape is a curve.

10. The method as recited in claim 4, wherein said partitioned portions contain a plurality of materials, one material per partition.

11. The method as recited in claim 1, wherein said electrostatic chuck has a base layer, wherein said one or more layers are disposed on said base layer along the outer periphery of said base layer.

12. The method as recited in claim 11, wherein said one or more layers are disposed on said base layer to form a ring.

13. The method as recited in claim 1, wherein said configured electrostatic chuck is placed in a second processing chamber for processing said second wafer.

14. The method as recited in claim 4, wherein said plasma includes ions and wherein said operation of configuring one or more layers comprises:

selecting said specified layer of said electrostatic chuck;

determining impedance each of the partitioned portions of the selected layer for providing DC bias to said second wafer, said DC bias for attracting said ions in a substantially uniform manner to said first wafer; and

configuring said selected layer to attract ions of a second plasma in a substantially uniform manner to said second wafer.

15. The method as recited in claim 14, wherein said selected layer is configured in a shape to provide said impedance.

16. The method as recited in claim 4, wherein said electrostatic chuck includes an electrode layer, wherein said electrode layer is partitioned into said plurality of portions, wherein said electrostatic chuck further includes a plurality of impedance elements coupled to said partitioned portions so as to provide varying DC bias on said wafers such that said non-uniformity characteristics are substantially compensated.

17. The method as recited in claim 1, wherein said plasma processing chamber has an electrode disposed over said wafer, wherein said electrode includes a plurality of electrically partitioned portions that are configured to substantially configured to compensate for said non-uniformity characteristics on said first wafer.

18. The method as recited in claim 17, wherein said electrode is arranged in a shape that is adapted to compensate for said non-uniformity characteristics.

19. The method as recited in claim 17, wherein said electrode is arranged to have a plurality of materials that are adapted to compensate for said non-uniformity characteristics.

20. The method as recited in claim 17, wherein a plurality of impedance elements are coupled to said partitioned portions so as to provide varying DC bias on said wafers such that said non-uniformity characteristics are substantially compensated.

21. The method as recited in claim 1, wherein said one or layers include a dielectric layer.

22. The method as recited in claim 1, wherein said one or more layers include an electrode layer.

23. A method for compensating non-uniform plasma processing in a plasma processing chamber having an electrostatic chuck for clamping a wafer, said processing chamber having an electrode disposed over said wafer, the method comprising:

processing a first wafer on said electrostatic chuck in a first plasma processing chamber, said first wafer being exposed to a plasma between said electrostatic chuck and an electrode in said first plasma processing chamber;

determining non-uniformity characteristics of said processed first wafer;

configuring said electrode into a plurality of electrically partitioned portions to substantially compensate for said non-uniformity characteristics on said first wafer; and

processing a second wafer on said configured electrode.

24. The method as recited in claim 23, wherein said non-uniformity characteristics of said processed first wafer is determined by measuring said processed first wafer at a plurality of radial positions.

25. The method as recited in claim 24, wherein said non-uniformity characteristics are determined by generating a uniformity curve showing a relationship between said processed first wafer and said radial positions.

26. The method as recited in claim 23, wherein said electrode is arranged in a shape that is adapted to compensate for said non-uniformity characteristics.

27. The method as recited in claim 23, wherein said electrode arranged to have a plurality of materials that are adapted to compensate for said non-uniformity characteristics.

28. The method as recited in claim 23, wherein said electrode is arranged to have a plurality of materials and in a shape such that said non-uniformity characteristics are substantially compensated.

29. An electrostatic chuck for clamping a wafer during plasma processing in a plasma processing chamber, comprising:

a first layer having a varying first impedance adapted to produce a varying DC bias over said wafer such that ions in a plasma in said plasma processing chamber are attracted to said wafer in a substantially uniform manner over said wafer; and

an electrode disposed under said first layer for transmitting RF power to said plasma.

30. The electrostatic chuck as recited in claim 29, wherein said first layer is partitioned into a plurality of electrically isolated portions that are arranged in a shape adapted to provide said varying impedance.

31. The electrostatic chuck as recited in claim 30, wherein said partitioned portions are arranged to have a plurality of materials that are adapted to provide said varying impedance.

32. The electrostatic chuck as recited in claim 29, wherein said varying impedance is produced by configuring said first layer to have a plurality of materials and in a shape so as to attract said ions to said wafer in said uniform manner.

33. The electrostatic chuck as recited in claim 29, wherein said first layer is a dielectric layer.

34. The electrostatic chuck as recited in claim 29, wherein said electrostatic chuck includes one or more dielectric layers and wherein said first layer is an electrode layer.

35. The electrostatic chuck as recited in claim 29, wherein said first layer includes at least one dielectric layer and an electrode layer.

36. The electrostatic chuck as recited in claim 34, wherein said electrostatic chuck includes an electrode layer, wherein said electrode layer is partitioned into a plurality of portions, wherein a plurality of impedance elements is coupled to said partitioned portions so as to provide varying DC bias on said wafer such that said non-uniformity characteristics are substantially compensated.