Systems and methods for purifying solvents

Patent metadata

Field	Value
Publication number	US-10773210-B2
Application number	US-201916684769-A
Country	US
Kind code	B2
Filing date	Nov 15, 2019
Priority date	Nov 20, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

The present disclosure is directed to methods of purifying solvents. The purified solvents can be used for cleaning a semiconductor substrate in a multistep semiconductor manufacturing process.

First claim

What is claimed is:

1. A method of purifying an organic solvent, comprising:
passing an organic solvent through a first filter to a packaging station in a purification system to obtain a purified organic solvent, the first filter comprising a filter housing and at least one filtration medium within the filter housing, and the at least one filtration medium having an average pore size of at most about 5 nm;
wherein the purification system comprises the first filter, the packaging station, and a conduit in fluid communication with the first filter and the packaging station, and the inner surface of the conduit or the filter housing comprises a fluoropolymer.

2. The method of claim 1 , further comprising passing the organic solvent through a second filter in fluid communication with and between the first filter and packaging station, wherein the second filter comprises a filter housing and at least one filtration medium within the filter housing, and the at least one filtration medium in the second filter has an average pore size of at most about 5 nm.

3. The method of claim 2 , wherein the at least one filtration medium in the first or second filter comprises a polyamide, a polyolefin, a fluoropolymer, or a copolymer thereof.

4. The method of claim 2 , wherein the at least one filtration medium in the first or second filter comprises a nylon, a polyethylene, a polytetrafluoroethylene, or a copolymer thereof.

5. The method of claim 2 , wherein the at least one filtration medium in the first filter comprises a nylon.

6. The method of claim 2 , wherein the at least one filtration medium in the second filter comprises a polytetrafluoroethylene.

7. The method of claim 2 , wherein the inner surface of the filter housing of the second filter comprises a fluoropolymer.

8. The method of claim 7 , wherein the fluoropolymer in the inner surface of the first filter, the second filter, or the conduit comprises a polytetrafluoroethylene or a copolymer thereof.

9. The method of claim 2 , wherein the entire second filter is made of a fluoropolymer.

10. The method of claim 2 , wherein the first filter comprises 1 to 120 filtration media, and the second filter comprises 1 to 30 filtration media.

11. The method of claim 1 , wherein passing the organic solvent through the first filter to the packaging station is performed at a temperature of at most about 80° F., or wherein the method further comprises passing the organic solvent through a heat exchanger to maintain the temperature of the organic solvent at most about 80° F.

12. The method of claim 1 , further comprising passing the organic solvent through a third filter before passing the organic solvent through the first filter, wherein the third filter comprises at least one filtration medium that has an average pore size of at most about 200 nm.

13. The method of claim 12 , further comprising passing the organic solvent through a fourth filter after passing the organic solvent through the third filter but before passing the organic solvent through the first filter, wherein the fourth filter comprises at least one ion exchange filtration medium.

14. The method of claim 13 , further comprising passing the organic solvent through a fifth filter after passing the organic solvent through the fourth filter but before passing the organic solvent through the first filter, wherein the fifth filter comprises at least one filtration medium that has an average pore size of at most about 20 nm.

15. The method of claim 1 , further comprising circulating the organic solvent through a recirculation loop comprising the first filter at least two times before passing the organic solvent to the packaging station.

16. The method of claim 1 , wherein the organic solvent comprises cyclohexanone, ethyl lactate, n-butyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 4-methyl-2-pentanol, or propylene carbonate.

17. A method of purifying an organic solvent, comprising:
passing an organic solvent through first and second filters to obtain a purified organic solvent;
wherein the first filter comprises at least one filtration medium that has an average pore size of at most about 5 nm and comprises a polyamide, and the second filter comprises at least one filtration medium that has an average pore size of at most about 5 nm and comprises a fluoropolymer.

18. The method of claim 17 , wherein the polyamide comprises a nylon and the fluoropolymer comprises a polytetrafluoroethylene.

19. The method of claim 17 , wherein the entire second filter is made of the fluoropolymer.

20. The method of claim 17 , wherein the first filter comprises 1 to 120 filtration media and the at second filter comprises 1 to 30 second filtration media.

21. The method of claim 17 , wherein passing the organic solvent is performed at a temperature of at most about 80° F. or wherein the method further comprises passing the organic solvent through a heat exchanger to maintain the organic solvent to the temperature of at most about 80° F.

22. The method of claim 17 , wherein the first filter comprises a filter housing and at least one filtration medium within the filter housing, the second filter comprises a filter housing and at least one filtration medium within the filter housing, and the inner surface of the filter housing of the first or second filter comprises a fluoropolymer.

23. The method of claim 17 , wherein the first and second filters are in a purification system; the purification system further comprises a packaging station, and a conduit in fluid communication with the first filter, the second filter, and the packaging station; and the inner surface of the conduit comprises a fluoropolymer.

24. The method of claim 17 , further comprising passing the organic solvent through a third filter before passing the organic solvent through the first and second filters, wherein the third filter comprises at least one filtration medium that has an average pore size of at most about 200 nm.

25. The method of claim 24 , further comprising passing the organic solvent through a fourth filter after passing the organic solvent through the third filter but before passing the organic solvent through the first and second filters, wherein the fourth filter comprises at least one ion exchange filtration medium.

26. The method of claim 25 , further comprising passing the organic solvent through a fifth filter after passing the organic solvent through the fourth filter but before passing the organic solvent through the first and second filters, wherein the fifth filter comprises at least one filtration medium that has an average pore size of at most about 20 nm.

27. The method of claim 17 , further comprising circulating the organic solvent through a recirculation loop comprising the first and second filters at least two times before passing the organic solvent to a packaging station.

28. The method of claim 17 , wherein the organic solvent comprises cyclohexanone, ethyl lactate, n-butyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 4-methyl-2-pentanol, or propylene carbonate.

29. A system, comprising:
a first filter, wherein the first filter comprises a filter housing and at least one filtration medium within the filter housing, and the at least one filtration medium has an average pore size of at most about

Assignees

• Fujifilm Electronic Mat Usa Inc

Inventors

• Cole-Yocom Marcia
• Hinzie Bryan
• Helzer Jack
• Chen Yuan
• Ahmadiannamini Pejman

Classifications

• H10P72/0402

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title

• B01D15/361 Primary

  Ion-exchange · CPC title

• B01D2311/25

  Recirculation, recycling or bypass, e.g. recirculation of concentrate into the feed · CPC title

• B01D2325/30

  Chemical resistance · CPC title

• B01D2313/206

  characterised by the material · CPC title