Damage Prevention on EUV Mask

• US 20170052443A1
• Filed: 08/21/2015
• Published: 02/23/2017
• Est. Priority Date: 08/21/2015
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Lin, Kuan-Wen, Lu, Chi-Lun, Shen, Ching-Wei, Wu, Shu-Hsien
• Granted Patent: US 9,740,094 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B08B 3/02 Cleaning by the force of jets or sprays
• CPC Class Codes: B08B 3/08 the liquid having chemical or dissolving effect substances used, see the relevant classes
• CPC Class Codes: B08B 3/10 with additional treatment of the liquid or of the object being cleaned, e.g. by heat, by electricity or by vibration
• CPC Class Codes: C11D 2111/20 Industrial or commercial equipment, e.g. reactors, tubes or engines
• CPC Class Codes: C11D 2111/22 Electronic devices, e.g. PCBs or semiconductors
• CPC Class Codes: C11D 3/3947 Liquid compositions
• CPC Class Codes: C11D 7/08 Acids
• CPC Class Codes: C11D 7/10 Salts
• CPC Class Codes: C11D 7/265 Carboxylic acids or salts thereof
• CPC Class Codes: C11D 7/34 containing sulfur
• CPC Class Codes: G03F 1/82 Auxiliary processes, e.g. cleaning or inspecting
• CPC Class Codes: G03F 7/2004 characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light

Abstract

A method of cleaning a photomask is disclosed. The method includes mixing a first chemical solution with a second chemical solution; and discharging the mixed chemical solution through an outlet of a nozzle to a surface of the photomask on which includes a ruthenium (Ru) layer, wherein the first chemical solution is configured to dislodge contaminant particles from the surface of the photomask and the second chemical solution is configured to provide an electron to the first chemical solution.

Claims

1. A method, comprising:

applying a first chemical solution and a second chemical solution to a photomask to remove contaminant particles from the photomask, wherein the photomask includes a ruthenium (Ru) layer and the second chemical solution prevents the first chemical solution from reacting with the Ru layer.

2. The method of claim 1, further comprising mixing the first chemical solution with the second chemical solution to form a mixed solution, and

wherein applying the first chemical solution and the second chemical solution to the photomask includes applying the mixed solution.

3. The method of claim 1, wherein the second chemical solution provides an electron to the first chemical solution to prevent the first chemical solution from reacting with the Ru layer.

4. The method of claim 1, further comprising applying a third chemical solution to the photomask to remove an organic compound from the photomask.

5. The method of claim 1, further comprising performing an extreme ultraviolet lithography process using the photomask.

6. The method of claim 1, wherein the first chemical solution includes at least one of:

water, carbonic acid, and hydrogen peroxide.

7. The method of claim 1, wherein the second chemical solution includes at least one of:

haloid, sulfite, sulfate, sodium borohydride, lithium borohydride, lithium aluminum hydride, and ascorbic acid.

8. The method of claim 1, wherein the applying the first chemical solution and the second chemical solution to the photomask is performed at a temperature ranging from room temperature to 50°

C.

9. A method of cleaning a photomask, comprising:

mixing a first chemical solution with a second chemical solution; and

discharging the mixed chemical solution through an outlet of a nozzle to a surface of the photomask on which includes a ruthenium (Ru) layer,

wherein the first chemical solution is configured to dislodge contaminant particles from the surface of the photomask and the second chemical solution is configured to provide an electron to the first chemical solution.

10. The method of claim 9, wherein the photomask is an extreme ultraviolet lithography (EUVL) mask.

11. The method of claim 9 further comprising prior to mixing the first chemical solution with the second chemical solution, supplying the first chemical solution and the second chemical solution respectively to a first inlet and a second inlet of the nozzle.

12. The method of claim 9, wherein the first chemical solution includes at least one of:

water, carbonic acid, and hydrogen peroxide.

13. The method of claim 9, wherein the second chemical solution includes at least one of:

haloid, sulfite, sulfate, sodium borohydride, lithium borohydride, lithium aluminum hydride, and ascorbic acid.

14. The method of claim 9 further comprising after discharging the mixed chemical solution through the nozzle to the surface of the photomask, exposing the surface of the photomask to a third chemical solution thereby removing an organic compound from the surface of the photomask.

15. The method of claim 14 further comprising after exposing the surface of the photomask to the third chemical solution, discharging the mixed chemical solution through the nozzle to the surface of the photomask.

16. The method of claim 9, wherein discharging the mixed chemical solution to the surface of the photomask is performed at a temperature ranging from room temperature to 50°

C.

17. A system for cleaning a photomask, comprising:

a first inlet that is configured to receive a first chemical solution;

a second inlet that is coupled to the first inlet and configured to receive a second chemical solution; and

an outlet that is coupled to the first and second inlets and configured to discharge a mixed chemical solution that includes the first and second chemical solutions to a surface of the photomask,

wherein the surface of the photomask includes a ruthenium (Ru) layer,

wherein the second chemical solution is configured to provide an electron to the first chemical solution thereby preventing an oxidized Ru layer being formed on the surface of the photomask.

18. The system of claim 17, wherein the photomask is an extreme ultraviolet lithography (EUVL) mask.

19. The system of claim 17, wherein the first chemical solution includes at least one of:

water, carbonic acid, and hydrogen peroxide.

20. The system of claim 17, wherein the second chemical solution includes at least one of:

haloid, sulfite, sulfate, sodium borohydride, lithium borohydride, lithium aluminum hydride, and ascorbic acid.