Apparatus and method for providing a confined liquid for immersion lithography

• US 7,367,345 B1
• Filed: 04/28/2004
• Issued: 05/06/2008
• Est. Priority Date: 09/30/2002
• Status: Expired due to Fees

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Korolik, Mikhail, de Larios, John M., Redeker, Fred C., Boyd, John, Ravkin, Michael, Hemker, David
• Primary Examiner(s): Perrin; Joseph L.
• Application Number:
  US10/834,548
• Time in Patent Office: 1,469 Days
• Field of Search: 134/95.1, 134/95.2, 134/99.1, 134/102.3, 134/113, 134/115.R, 134/122.P, 134/172, 134/902, 355/30
• US Class Current: 134/95.2
• 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: Y10S 134/902 Semiconductor wafer

Abstract

A method for processing a substrate is provided which includes generating a meniscus on the surface of the substrate and applying photolithography light through the meniscus to enable photolithography processing of a surface of the substrate.

Claims

1. An apparatus for processing a substrate, comprising:

a proximity head configured to generate a fluid meniscus to facilitate patterning of a photoresist on a substrate surface, the fluid meniscus being constantly replenished with fluid by addition of the fluid into the fluid meniscus and by removal of the fluid from the fluid meniscus by a vacuum, the proximity head having source inlets that introduce a surface tension reducing gas, the surface tension reducing gas being configured to reduce surface tension of the fluid meniscus relative to the substrate surface, and the proximity head further having a head surface that has flat surface regions, the head surface is defined with discrete holes to pass the fluid, the vacuum, and the surface tension reducing gas, the discrete holes reside at the head surface and extend through the flat surface regions of the head surface; and

a lithography lens structure at least partially defined within the proximity head, the lithography lens structure having a lithography lens configured to be in direct contact with the fluid meniscus during operation, the lithography lens structure configured to apply a patterned light from the lithography lens through the fluid meniscus to pattern the photoresist on the substrate surface.

2. An apparatus for processing a substrate as recited in claim 1, wherein the lithography lens structure is attached to a column system which includes a light source and a reticle for generating the patterned light.

3. An apparatus for processing a substrate as recited in claim 1, wherein the proximity head includes a plurality of conduits capable of defining the fluid meniscus.

4. An apparatus for processing a substrate as recited in claim 2, wherein the lithography lens is substantially surrounded by the plurality of conduits.

5. An apparatus for processing a substrate as recited in claim 1, wherein the fluid has a refractive index greater than 1.

6. An apparatus for processing a substrate as recited in claim 1, wherein the

patterned light has a first wavelength before entering the fluid meniscus, and the patterned light when transmitted through the fluid meniscus and applied to the photoresist has a effective wavelength shorter than the first wavelength.

7. An apparatus for processing a substrate as recited in claim 3, wherein the plurality of conduits includes at least one of a first inlet for applying the fluid to the photoresist, the source inlets for applying the surface tension reducing gas to the photoresist, and an outlet for removing the fluid and the surface tension reducing gas from the photoresist.

8. An apparatus for processing a substrate as recited in claim 7, wherein the surface tension reducing gas is a vapor gas that promotes a surface tension gradient at a border of the fluid meniscus.

9. An apparatus for processing a substrate as recited in claim 8, wherein the vapor gas is one of an alcohol vapor, a ketone vapor, and an ether vapor in an inert gas.

10. An apparatus for processing a substrate as recited in claim 8, wherein the vapor gas is IPA/N₂.

11. An apparatus for processing a substrate, comprising:

a proximity head capable of generating a fluid meniscus to process a photoresist on a substrate surface, the fluid meniscus being constantly replenished with fluid by addition of the fluid into the fluid meniscus and by removal of the fluid from the fluid meniscus by a vacuum, the proximity head having source inlets that introduce a surface tension reducing gas, the surface tension reducing gas being configured to reduce surface tension of the fluid meniscus relative to the substrate surface, and the proximity head further having a head surface that has flat surface regions, the head surface is defined with discrete holes to pass the fluid, the vacuum, and the surface tension reducing gas, the discrete holes reside at the head surface and extend through the flat surface regions of the head surface; and

a light generating source at least partially defined within the proximity head, the light generating source configured to be in direct contact with the fluid meniscus during operation, the light generating source capable of applying a patterned light into and through the fluid meniscus, the patterned light having a first wavelength before entrance into the fluid meniscus and an effective wavelength when applied to the photoresist through the fluid meniscus, the effective wavelength being shorter than the first wavelength.

12. An apparatus for processing a substrate as recited in claim 11, wherein the light generating source comprises a column system and a lithography lens structure, the column system including a light source and a reticle for generating the patterned light, lithography lens structure including a lens configured to be in direct contact with the fluid meniscus in operation and further configured to directly apply the patterned light to the fluid meniscus.

13. An apparatus for processing a substrate as recited in claim 12, wherein the lens is substantially surrounded by a plurality of conduits.

14. An apparatus for processing a substrate as recited in claim 11, wherein the proximity head includes a plurality of conduits capable of defining the fluid meniscus.

15. An apparatus for processing a substrate as recited in claim 14, wherein the plurality of conduits includes at least one of a first inlet for applying the fluid to the photoresist, the source inlets for applying the surface tension reducing gas to the photoresist, and an outlet for removing the fluid and the surface tension reducing gas from the photoresist.

16. An apparatus for processing a substrate as recited in claim 15, wherein the surface tension reducing gas is a vapor gas that promotes a surface tension gradient at a border of the fluid meniscus.

17. An apparatus for processing a substrate as recited in claim 16, wherein the vapor gas is one of an alcohol vapor, a ketone vapor, and an ether vapor in an inert gas.

18. An apparatus for processing a substrate as recited in claim 16, wherein the vapor gas is IPA/N₂.

19. An apparatus for processing a substrate as recited in claim 11, wherein the fluid meniscus is made up of a liquid with a refractive index greater than 1.

20. A photolithography apparatus, comprising:

a proximity head, the proximity head being capable of generating a meniscus on a surface of a substrate, the proximity head having source inlets that introduce a surface tension reducing gas, the surface tension reducing gas being configured to reduce surface tension of the fluid meniscus relative to a substrate surface and the proximity head further having a head surface that has flat surface regions, the head surface is defined with discrete holes to pass a fluid, a vacuum, and the surface tension reducing gas, and the discrete holes reside at the head surface and extend through the flat surface regions of the head surface; and

a light source for applying photolithography light from the proximity head and through the meniscus, the photolithography light being configured to contact the surface of the substrate to enable photolithography processing.

21. An apparatus for processing a substrate as recited in claim 20, wherein the proximity head includes a plurality of conduits capable of defining the meniscus.

22. An apparatus for processing a substrate as recited in claim 20, wherein the meniscus is made up of a liquid with a refractive index greater than 1.