Method and apparatus for producing ultra-high purity water

• US 20070084793A1
• Filed: 10/18/2005
• Published: 04/19/2007
• Est. Priority Date: 10/18/2005
• Status: Abandoned Application

• Current Assignee: Air Liquide Electronics US LP (Air Liquide SA)
• Original Assignee: Air Liquide Electronics US LP (Air Liquide SA)
• Inventors: Wenden, Nigel
• Application Number:
  US11/252,635
• Publication Number:
  US 20070084793A1
• Time in Patent Office: Days
• US Class Current: 210/641
• CPC Class Codes: B01D 19/0031 by filtration
• CPC Class Codes: B01D 2317/08 Use of membrane modules of different kinds
• CPC Class Codes: C02F 1/001 Processes for the treatment of water whereby the filtration technique is of importance C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00
• CPC Class Codes: C02F 1/20 by degassing, i.e. liberation of dissolved gases degasification of liquids in general B01D19/00; arrangement of degassing apparatus in boiler feed supply F22D
• CPC Class Codes: C02F 1/32 with ultraviolet light
• CPC Class Codes: C02F 1/42 by ion-exchange ion-exchange in general B01J
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration
• CPC Class Codes: C02F 2103/04 for obtaining ultra-pure water
• CPC Class Codes: C02F 9/20 Portable or detachable small-scale multistage treatment devices, e.g. point of use or laboratory water purification systems

Abstract

The present invention relates to a system and method for producing ultrapure water, particular for use in immersion lithography processes. In one embodiment of the present invention, a self contained point-of-use cabinet that can consistently provide ultrapure water for use in immersion lithography equipment is provided. The present invention also relates to a system and method for providing a material having a predetermined specific refractive index to an immersion lithography device.

Claims

1. A system for providing ultrapure water to a immersion lithography device, the system comprising:

a prefilter in fluid communication with a water supply;

a reverse osmosis unit in fluid communication with the prefilter;

a deionization unit in fluid communication with the reverse osmosis unit;

an ultraviolet light unit in fluid communication with the deionization unit;

a filter in fluid communication with the ultraviolet light unit;

a degasser in fluid communication with the filter; and

an ultrafilter in fluid communication with the degasser;

wherein ultrapure water exits the system from the ultrafilter and may be used by the immersion lithography device.

2. A system according to claim 1, wherein the system is housed in a single cabinet.

3. A system according to claim 2, wherein the cabinet is a point-of-use cabinet.

4. A system according to claim 1, further comprising:

a storage vessel in fluid communication with the reverse osmosis unit; and

a pump in fluid communication with the storage vessel and the deionization unit.

5. A system according to claim 4, wherein the system is housed in a single cabinet.

6. A system according to claim 5, wherein the cabinet is a point-of-use cabinet.

7. A system according to claim 1, wherein the deionization unit, the ultraviolet light unit, the filter, the degasser, and the ultrafilter are housed in a single cabinet.

8. A system according to claim 7, wherein the cabinet is a point-of-use cabinet.

9. A system according to claim 1, wherein the reverse osmosis unit and the ultrafilter are in fluid communication with a system drain.

10. A system according to claim 4, wherein the storage vessel is in fluid communication with a system drain.

11. A system according to claim 1, further comprising means to add dopants to the ultrapure water.

12. A system according to claim 11, wherein said means includes flow controllers.

13. A system according to claim 12, wherein said means further includes mixing means.

14. A method of producing ultrapure water for an immersion lithography process, the method comprising:

treating a water supply by prefiltration to obtain prefiltered water;

treating the prefiltered water by reverse osmosis to remove ions and large molecules;

treating the water from the reverse osmosis process using ultraviolet light to remove impurities and suspend solids;

treating the water from the ultraviolet light process by filtration to obtain filtered water;

treating the filtered water by degassification to

treating the water from the degassification process to ultrafiltration to obtain ultrapure water.

15. A method according to claim 14, further comprising:

storing the water from the reverse osmosis process until requested for use by the immersion lithography process.

16. A method according to claim 14, further comprising:

adding a dopant to the ultrapure water.

17. A system for providing a medium having a specific predetermined refractive index to an immersion lithography device, the system comprising:

a source of ultrapure water;

a source of at least one dopant material; and

means for combining the ultrapure water and the at least one dopant material to obtain the medium.

18. A system according to claim 17, wherein said means for combining includes a separate flow controller for the ultrapure water and for each of the at least one dopant material.

19. A system according to claim 18, wherein said means further includes mixing means.

20. A method for providing a medium having a specific predetermined refractive index to an immersion lithography device, the method comprising:

providing a precise quantity of ultrapure water; and

adding a precise quantity of at least one dopant material to the ultrapure water to obtain the medium.

21. A method according to claim 20, wherein said adding is carried out using a separate flow controller for the ultrapure water and for each of the at least one dopant material.

22. A system according to claim 20, further comprising:

mixing the ultrapure water and the at least one dopant material.