Waffle wafer chuck apparatus and method

• US 20040025322A1
• Filed: 08/06/2002
• Published: 02/12/2004
• Est. Priority Date: 08/06/2002
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Binnard, Michael
• Application Number:
  US10/212,886
• Publication Number:
  US 20040025322A1
• Time in Patent Office: Days
• US Class Current: 29/592.1
• CPC Class Codes: G03F 7/707 Chucks, e.g. chucking or un-chucking operations or structural details
• CPC Class Codes: G03F 7/70708 being electrostatic; Electrostatically deformable vacuum chucks
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

An apparatus for holding a substrate includes slots to increase accuracy required for precision manufacturing. The holding apparatus has a flat upper surface configured to attach to the substrate, a lower surface parallel to the upper surface of the holding apparatus having a number of slots extending lengthwise across the lower surface and depth wise towards the upper surface facilitating flexibility in the lower surface. In one implementation, a wafer chuck having slots in its lower surface and supported by a based flexes to accommodate imperfections in the surface of the base. Because of the slots, the lower surface of the wafer chuck flexes without flexing the upper surface of the wafer chuck and the wafer or other substrate mounted on the upper surface of the wafer chuck. This reduces distortion in the wafer during fabrication and facilitates the high degree of accuracy required for precision manufacturing.

Claims

1. An apparatus for supporting a substrate for processing during precision manufacturing, comprising:

a holding member having a flat upper surface configured to attach to the substrate; and

a lower surface parallel to the upper surface of the holding member having a number of slots extending lengthwise across the lower surface and depth wise towards the upper surface facilitating flexibility in the lower surface.

2. The apparatus in claim 1 further comprising an annular area parallel to the lower surface and covering a portion of the slots associated with the lower surface that facilitates using the holding member with precision manufacturing equipment.

3. The apparatus of claim 1 wherein the substrate is a semiconductor wafer.

4. The apparatus of claim 1 wherein the precision manufacturing includes microlithography.

5. The apparatus of claim 1 wherein the holding member is a wafer chuck.

6. The apparatus of claim 1 wherein the holding member uses electrostatic forces to secure the substrate to the upper surface of the holding member.

7. The apparatus of claim 1 wherein the holding member uses vacuum forces to secure the substrate to the upper surface of the holding member.

8. The apparatus of claim 1 wherein the holding member has a width (W) and the depth of the slots are approximately 10% and more than 10% to under 60% the width (W) of the holding member.

9. The apparatus of claim 1 wherein the holding member has a width (W) and the depth of the slots are approximately 60% and more than 60% to under 70% the width (W) of the holding member.

10. The apparatus of claim 1 wherein the holding member has a width (W) and the depth of the slots are approximately 70% and more than 70% to under 80% the width (W) of the holding member.

11. The apparatus of claim 1 wherein the holding member has a width (W) and the depth of the slots are approximately 80% and more than 80% to under 90% the width (W) of the holding member.

12. The apparatus of claim 1 wherein a portion of the slots covered by a surface parallel to the lower surface creates a bearing surface.

13. A precision manufacturing apparatus that supports a substrate during processing, comprising:

an energy emission system;

a holding member in line with the energy emission system having a flat upper surface configured to attach to the substrate and a lower surface parallel to the upper surface of the holding member having a number of slots extending lengthwise across the lower surface and depth wise towards the upper surface facilitating flexibility in the lower surface;

a substrate table that attaches to the lower surface of the holding member and configured to adjust the tilt of the holding member and facilitate focusing energy from the energy emission system; and

a stage coupled to the substrate table that facilitates movement of substrate table along one or more axes relative to the energy emission system.

14. The apparatus in claim 13 wherein the holding member further comprises an annular area parallel to the lower surface and covering a portion of the slots associated with the lower surface that facilitates using the holding member with precision manufacturing equipment.

15. The apparatus of claim 13 wherein the substrate is a semiconductor wafer.

16. The apparatus of claim 13 wherein the precision manufacturing includes microlithography.

17. The apparatus of claim 13 wherein the holding member is a wafer chuck.

18. The apparatus of claim 13 wherein the holding member uses electrostatic forces to secure the substrate to the upper surface of the holding member.

19. The apparatus of claim 13 wherein the holding member uses vacuum forces to secure the substrate to the upper surface of the holding member.

20. The apparatus of claim 13 wherein the holding member has a width (W) and the depth of the slots are approximately 10% and more than 10% to under 60% the width (W) of the holding member.

21. The apparatus of claim 13 wherein the holding member has a width (W) and the depth of the slots are approximately 60% and more than 60% to under 70% the width (W) of the holding member.

22. The apparatus of claim 13 wherein the holding member has a width (W) and the depth of the slots are approximately 70% and more than 70% to under 80% the width (W) of the holding member.

23. The apparatus of claim 13 wherein the holding member has a width (W) and the depth of the slots are approximately 80% and more than 80% to under 90% the width (W) of the holding member.

34. The method of claim 23 wherein the holding member has a width (W) and the depth of the slots are approximately 80% and more than 80% to under 90% the width (W) of the holding member.

49. The apparatus in claim 13 wherein the holding member further comprises a bearing surface covering a portion of the slots and parallel to the lower surface that facilitates using the holding member with precision manufacturing equipment.

24. A method of supporting a substrate during precision manufacturing, comprising:

providing a holding member having a flat upper surface configured to attach to the substrate and a lower surface parallel to the upper surface of the holding member having a number of slots extending lengthwise across the lower surface and depth wise towards the upper surface facilitating flexibility in the lower surface;

attaching the substrate to the upper surface of the holding member;

coupling the lower surface of the holding member the surface of a substrate table; and

allowing the slots associated with the lower surface of the holding member to expand and contract in response to variations in the surface of the substrate table thereby minimizing the amount of distortion associated with the substrate attached to the upper surface of the holding member.

25. The method of claim 24, further comprises creating an annular area parallel to the lower surface and covering a portion of the slots associated with the lower surface that facilitates using the holding member with precision manufacturing equipment.

26. The method of claim 24 wherein the substrate is a semiconductor wafer.

27. The method of claim 24 wherein the precision manufacturing includes microlithography processing.

28. The method of claim 24 wherein the holding member is a wafer chuck.

29. The method of claim 24 wherein the holding member utilizes electrostatic forces to secure the substrate to the upper surface of the holding member.

30. The method of claim 24 wherein the holding member uses vacuum forces to secure the substrate to the upper surface of the holding member.

31. The method of claim 24 wherein the holding member has a width (W) and the depth of the slots are approximately 10% and more than 10% to under 60% the width (W) of the holding member.

32. The method of claim 24 wherein the holding member has a width (W) and the depth of the slots are approximately 60% and more than 60% to under 70% the width (W) of the holding member.

33. The method of claim 24 wherein the holding member has a width (W) and the depth of the slots are approximately 70% and more than 70% to under 80% the width (W) of the holding member.

50. The method in claim 24 further comprising creating a bearing surface on the holding member covering a portion of the slots and parallel to the lower surface that facilitates using the holding member with precision manufacturing equipment.

35. A method operating a precision manufacturing apparatus that supports a substrate during processing, comprising:

providing a holding member having a flat upper surface configured to attach to the substrate and a lower surface parallel to the upper surface of the holding member having a number of slots extending lengthwise across the lower surface and depth wise towards the upper surface facilitating flexibility in the lower surface;

attaching the substrate to the upper surface of the holding member;

coupling the lower surface of the holding member to the surface of a substrate table;

allowing the slots associated with the lower surface of the holding member to expand and contract in response to variations in the surface of the substrate table thereby minimizing the amount of distortion associated with the substrate attached to the upper surface of the holding member;

exposing the substrate to energy from an energy emission system;

adjusting the tilt of the holding member while focusing energy from the energy emission system onto the substrate; and

moving the substrate along one or more axes relative to the energy emission system to expose different portions of the substrate to energy from the energy emission system.

36. A method of making an object that includes the method of operating a precision manufacturing apparatus in claim 35.

51. The method in claim 35 wherein the holding member further comprises a bearing surface covering a portion of the slots and parallel to the lower surface that facilitates using the holding member with precision manufacturing equipment.

37. A method of manufacturing a holding member used for supporting a substrate in precision manufacturing, comprising:

creating a holding member having an upper surface configured to attach to the substrate and a lower surface parallel to the upper surface of the holding member having a number of slots extending lengthwise across the lower surface and depth wise towards the upper surface facilitating flexibility in the lower surface;

filling the slots on the lower surface with a temporary filler material that strengthens the holding member;

precision machining the upper surface of the holding member to articulate with the substrate; and

removing the temporary material from each slot in the lower surface of the holding member once the precision machining of the upper surface is complete.

38. The method of claim 37 wherein the holding member is a wafer chuck used in microlithography.

39. The method of claim 37 wherein the filling of the slots enables the upper surface to withstand the forces associated with the precision machining.

40. The method of claim 37 wherein creating of the holding member further comprises casting the holding member using a die.

41. The method of claim 37 wherein lathes and precision machinery are used to create the holding member.

42. The method of claim 37 wherein the precision machining includes lapping the upper surface of the holding member.

43. The method of claim 37 further comprising,

placing an annular area parallel to the lower surface and covering a portion of the slots associated with the lower surface to facilitate using the holding member with precision manufacturing equipment.

44. The method of claim 37 wherein the substrate is a semiconductor wafer.

45. The method of claim 37 wherein the precision manufacturing includes microlithography.

46. The method of claim 37 wherein the holding member is a wafer chuck.

47. The method of claim 37 wherein the holding member uses electrostatic forces to secure the substrate to the upper surface of the holding member.

48. The method of claim 37 wherein the holding member uses vacuum forces to secure the substrate to the upper surface of the holding member.

52. The method in claim 37 further comprising creating a bearing surface on the holding member covering a portion of the slots and parallel to the lower surface that facilitates using the holding member with precision manufacturing equipment.