Granted Patent B2

US 7,329,308 · App. 10/888,573 · Granted Feb 12, 2008

Abstract

Claims (47)

1. A method for filtering a gas stream for a semiconductor processing tool, comprising the steps of:

providing an output gas stream from a semiconductor tool, the output gas stream having contaminants;

providing a flow of a scrubbing liquid onto an absorption structure through an inlet to an absorption section;

contacting the output gas stream with the scrubbing liquid on the absorption structure within the absorption section such that a concentration of one or more of the contaminants in the output gas stream is reduced by sorption in the scrubbing liquid to produce an outgoing gas stream;

removing droplets of scrubbing liquid from the outgoing gas stream to produce a return gas stream; and

providing the return gas stream to the semiconductor processing tool.

2. The method of claim 1 , wherein the semiconductor processing tool comprises a photolithography tool or photolithography tool cluster.

3. The method of claim 1 , wherein the scrubbing liquid comprises water.

4. The method of claim 1 , wherein the scrubbing liquid comprises de-ionized water having a resistivity in the range from about 100,000 Ω cm to about 18 MΩ cm.

5. The method of claim 1 , wherein the scrubbing liquid comprises one or more additives that facilitate reducing the concentration of one or more contaminants in the output gas stream.

6. The method of claim 1 , further comprising the steps of:

controlling the temperature of the return gas stream; and

controlling the relative humidity of the return gas stream.

7. The method of claim 1 , wherein:

the temperature of the return gas stream is controlled such that the variation in the temperature of the return gas stream is less than about 50 milliKelvin; and

the relative humidity of the return gas stream is controlled such that the variation in the relative humidity of the return gas stream is less than about 0.2 percent.

8. The method of claim 1 further comprising scrubbing with a liquid non-polar solvent.

9. The method of claim 1 further comprising atomizing the scrubbing liquid with a liquid atomizer.

10. The method of claim 1 further comprising providing an absorption structure including a loose packed-bed.

11. The method of claim 1 wherein step of providing the output gas stream comprises providing air.

12. The method of claim 1 further comprising providing an inlet for receiving the output gas stream of the first absorption section to provide a co-current filtering process.

13. The method of claim 1 further comprising providing an inlet for receiving the output gas stream of the first absorption section to provide a counter-current filtering process.

14. The method of claim 1 further comprising illuminating the output gas stream with light.

15. The method of claim 1 further comprising illuminating the output gas stream with ultraviolet light.

16. The method of claim 1 further comprising removing acid, base and refractory compound contaminants from the output gas stream.

17. The method of claim 1 further comprising removing organic compounds from the output gas stream.

18. The method of claim 1 further comprising:

providing an outlet in the first absorption section for providing an outgoing gas stream;

providing a first inlet in a second absorption section for receiving a scrubbing liquid;

providing an absorption structure positioned in the second absorption section such that scrubbing liquid wets a surface of the absorption structure and flows down the absorption structure;

providing a second inlet in the second absorption section for receiving the outgoing gas stream from the first absorption section, the outgoing gas stream having one or more contaminants; and

the second absorption section configured such that the outgoing gas stream contacts scrubbing liquid on the surface of the absorption structure in the second absorption section and the concentration of the one or more contaminants in the gas stream is reduced by sorption in the scrubbing liquid.

19. The method of claim 18 , wherein one of the first absorption section and second absorption section is configured to be operated as a counter-current system and the other of the first absorption section and second absorption section is configured to be operated as a co-current system.

20. The method of claim 1 , further comprising providing a temperature control unit positioned in the flow of the scrubbing liquid to provide a temperature controlled scrubbing liquid to the inlet in the absorption section.

21. The method of claim 1 , further comprising providing a heat exchanger positioned to exchange heat between the output gas stream and return gas stream.

22. The method of claim 1 , further comprising providing a gas temperature control unit positioned in the return gas stream, the gas temperature control unit controlling the temperature of the return gas stream.

23. The method of claim 20 or 22 , further comprising controlling the temperature and humidity of the return gas stream with the gas temperature control unit together with the temperature control unit.

24. A method for filtering and conditioning a gas stream for a semiconductor processing tool, comprising the steps of:

providing an output gas stream from a semiconductor tool, the output gas stream having contaminants;

providing a flow of a scrubbing liquid onto an absorption structure through an inlet to an absorption section;

contacting the output gas stream with the scrubbing liquid on the absorption structure within the absorption section such that a concentration of one or more of the contaminants in the output gas stream is reduced by sorption in the scrubbing liquid to produce an outgoing gas stream;

removing droplets of scrubbing liquid from the outgoing gas stream to produce a return gas stream;

controlling the temperature and humidity of the return gas stream; and

providing the controlled return gas stream to the semiconductor processing tool.

25. The method of claim 24 further comprising controlling:

the temperature of the return gas stream such that the variation in the temperature of the return gas stream is less than about 50 milliKelvin; and

the relative humidity of the return gas stream is controlled such that the variation in the relative humidity of the return gas stream is less than about 0.2 percent.

Assignments (12)