Controlling shape of a reticle with low friction film coating at backside

• US 20080204694A1
• Filed: 02/28/2007
• Published: 08/28/2008
• Est. Priority Date: 02/28/2007
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Chen, George, Shu, Emily Y.
• Granted Patent: US 7,759,024 B2
• Time in Patent Office: Days
• US Class Current: 355/75
• CPC Class Codes: G03B 27/62 Holders for the original G03B27/53 takes precedence ; for electrophotographic copiers G03G15/60

Abstract

In an embodiment of the invention, an apparatus includes a reticle having a frontside including a pattern to be imaged onto a semiconductor wafer, a thin film located over a backside of the reticle to form a global convex shape and to reduce friction when sliding on a chuck, and the chuck having a topside to which the backside of the reticle conforms.

Claims

1. An apparatus comprising:

a reticle, said reticle having a frontside and a backside, said frontside including a pattern;

said backside having a thin film, said thin film being adherent to said backside, said thin film applying stress to said reticle to form a global convex shape, said thin film having low friction when sliding.

2. The apparatus of claim 1, further comprising an electrostatic chuck having a topside disposed in proximity to said backside of said reticle, said electrostatic chuck being stiffer than said reticle.

3. The apparatus of claim 2, wherein said backside of said reticle conforms in shape to said topside of said electrostatic chuck from an inner region of the reticle to an outer region of the reticle.

4. The apparatus of claim 3, further comprising a lubricating fluid disposed over said topside of said electrostatic chuck, said lubricating fluid having a thickness that varies by position over said electrostatic chuck, force of contact, duration of contact, and temperature.

5. The apparatus of claim 4 wherein said lubricating fluid has non-Newtonian rheological properties.

6. The apparatus of claim 4, wherein said thin film adherent to said backside of said reticle is electrically conductive.

7. The apparatus of claim 4, wherein said thin film adherent to said backside of said reticle is electrically insulating.

8. The apparatus of claim 4, wherein said thin film adherent to said backside of said reticle comprises non-crystalline carbon.

9. The apparatus of claim 4, wherein said lubricating fluid is disposed between said topside of said electrostatic chuck and said thin film overlying said backside of said reticle.

10. A method comprising:

forming a thin film over a backside of a reticle;

deforming said reticle into a global convex shape;

coupling voltage across said thin film; and

reducing friction of said backside of said reticle when sliding.

11. The method of claim 10, further comprising forming a lubricating fluid over a topside of an electrostatic chuck.

12. The method of claim 10, further comprising:

positioning said backside of said reticle over said topside of said electrostatic chuck;

contacting high points of said backside of said reticle to said topside of said electrostatic chuck;

coupling a voltage across said electrostatic chuck and said reticle; and

reducing a gap between said backside of said reticle and said topside of said electrostatic chuck.

13. The method of claim 12, further comprising:

conforming said backside of said reticle to said topside of said electrostatic chuck.

14. The method of claim 12 further comprising performing an extreme ultraviolet lithography process to transfer a pattern from said frontside of said reticle to a semiconductor wafer.

15. The method of claim 12 further comprising decoupling said voltage across said thin film.

16. The method of claim 12, further comprising forming said thin film with a plurality of layers including a base layer and an overlying layer, wherein said base layer comprises a high adhesion material and said overlying layer comprises a low sliding friction material.

17. The method of claim 12, further comprising performing a rework operation on said thin film.