LITHOGRAPHIC APPARATUS AND DEVICE MANUFACTURING METHOD

• US 20100321652A1
• Filed: 08/31/2010
• Published: 12/23/2010
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Gohoel-Van Ansem, Wendy Fransisca Johanna, Streefkerk, Bob, Dierichs, Marcel Mathijs Theodore Marie
• Granted Patent: US 8,416,385 B2
• Time in Patent Office: Days
• US Class Current: 355/30
• CPC Class Codes: G03F 7/70341 Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply chemical composition of immersion liquids G03F7/2041
• CPC Class Codes: G03F 7/70866 of mask or workpiece
• CPC Class Codes: G03F 7/70958 Optical materials or coatings, e.g. with particular transmittance, reflectance or anti-reflection properties

Abstract

A lithographic apparatus and device manufacturing method is provided in which exposure is carried out by projecting through a liquid having a pH of less than 7, the liquid being in contact with a substrate to be exposed. The liquid advantageously comprises an anti-reflective topcoat.

Claims

1. An immersion lithographic system comprising:

an optical surface;

a wafer support for holding a workpiece; and

an immersion fluid with a pH less than 7, disposed between the optical surface and the wafer support, said immersion fluid contacting at least a portion of the optical surface.

2. The system of claim 1 wherein the immersion fluid comprises water.

3. The system of claim 2 wherein the pH of said immersion fluid is in the range of 2 to 7.

4. The system of claim 3 wherein the pH of said immersion fluid is in the range of 4 to 7.

5. The system of claim 4 wherein the pH of said immersion fluid is in the range of 5 to 7.

6. The system of claim 5 wherein the pH of said immersion fluid is in the range of 6 to 7.

7. The system of claim 1 further comprising a semiconductor structure on the wafer support structure, said semiconductor structure having a topmost photosensitive layer.

8. The system of claim 7 wherein the photosensitive layer comprises a chemically amplified photoresist.

9. The system of claim 7 wherein the immersion fluid is in contact with a portion of the photosensitive layer.

10. The system of claim 7 wherein the semiconductor structure is immersed in the immersion fluid.

11. The system of claim 7 wherein the wafer support is immersed in the immersion fluid.

12. An immersion lithographic system for projecting light having a wavelength of less than 197 nm, the system comprising:

an optical surface;

water with a pH less than 7, said water contacting at least a portion of the optical surface; and

a semiconductor structure having a topmost photoresist layer, a portion of said photoresist being in contact with the water.

13. The system of claim 12 wherein the pH of the water is in the range of 2 to 7.

14. The system of claim 13 wherein the pH of the water is in the range of 5 to 7.

15. The system of claim 14 wherein the pH of the water is in the range of 6 to 7.

16. The system of claim 12 further comprising a fluoride containing compound dissolved in the water.

17. The system of claim 12 wherein the photoresist layer comprises a chemically amplified photoresist.

18. The system of claim 12 wherein the semiconductor structure is immersed in the water.

19. The system of claim 12 further comprising a wafer support underlying the semiconductor structure.

20. The system of claim 19 wherein the wafer support is immersed in the water.

21-82. -82. (canceled)