Air manager apparatus and method for exhausted equipment and systems, and exhaust and airflow management in a semiconductor manufacturing facility

• US 6,280,507 B1
• Filed: 02/29/2000
• Issued: 08/28/2001
• Est. Priority Date: 02/29/2000
• Status: Expired due to Fees

• Current Assignee: Advanced Technology Materials, Inc. (Entegris Incorporated)
• Original Assignee: Advanced Technology Materials, Inc. (Entegris Incorporated)
• Inventors: Walker, Bruce
• Primary Examiner(s): Simmons, David A.
• Assistant Examiner(s): PHAM, MINH CHAU THI
• Application Number:
  US09/515,485
• Time in Patent Office: 546 Days
• Field of Search: 553/851, 553/852, 55D/IG.18, 55D/IG.29, 454/187, 454/188, 454/189, 454/190, 454/191, 454/192, 454/193, 438/905, 438/909
• US Class Current: 95/273
• CPC Class Codes: B01D 53/74 General processes for purification of waste gases; Apparatus or devices specially adapted therefor B01D53/92 takes precedence
• CPC Class Codes: F24F 2007/001 with exhausting air ducts
• CPC Class Codes: F24F 3/167 Clean rooms, i.e. enclosed spaces in which a uniform flow of filtered air is distributed air distribution by perforated walls F24F7/10
• CPC Class Codes: F24F 7/003 in combination with air cleaning
• CPC Class Codes: H01L 21/67017 Apparatus for fluid treatment H01L21/67126, H01L21/6715 take precedence
• CPC Class Codes: H01L 21/6715 Apparatus for applying a liquid, a resin, an ink or the like H01L21/67126 takes precedence
• CPC Class Codes: Y10S 55/18 Work bench
• CPC Class Codes: Y10S 55/29 Air curtains

Abstract

An air manager for the containment of hazardous fumes over a liquid chemical tank in exhausted equipment and systems in a clean room. A powered, filtered airflow source forces filtered air through a plenum coextensive with a transverse dimension of the chemical tank, in a sheet-like airflow stream over the liquid surface. The airflow is captured at the opposite side of the liquid chemical tank and directed to a powered exhaust. The air manager works cooperatively with the clean room laminar airflow, dramatically increasing the efficiency of the local exhaust. Critical Capture Velocity over the entire surface of the tank is maintained, assuring complete containment of chemical fumes. Optional airflow guides positioned along the sides of the chemical tank may be employed to confine the air stream to the area over the liquid surface.

Claims

1. An air manager and chemical tank assembly, comprising:

a filtered airflow source constructed and arranged to direct airflow in an airflow stream;

a liquid chemical tank arranged to contain a liquid producing deleterious fumes at said liquid'"'"'s surface, and an airflow exhaust having an inlet for receiving said airflow;

wherein the filtered airflow source and airflow exhaust are positioned in relation to one another so that airflow from the filtered airflow source is directed over the surface of the liquid and into the exhaust inlet, whereby substantially all deleterious fumes produced at the surface of the chemical are captured by and entrained in the airflow, and transported to the exhaust.

2. The air manager and chemical tank assembly of claim 1, wherein the filtered airflow source is positioned above and adjacent to one side of the liquid chemical tank and the inlet to the powered exhaust is positioned in proximity to an opposite side of the liquid chemical tank.

3. The air manager and chemical tank assembly of claim 1, wherein the filtered airflow source is positioned above and adjacent to opposing sides of the liquid chemical tank.

4. The air manager and chemical tank assembly of claim 1, wherein the airflow stream from the filtered airflow source is directed parallel to said liquid'"'"'s surface.

5. The air manager and chemical tank assembly of claim 1, wherein the filtered airflow source comprises at least one airflow purification medium, selected from the group consisting of particulate filter media and chemisorbent media.

6. The air manager and chemical tank assembly of claim 1, further comprising at least two airflow guides extending from the airflow source to the airflow exhaust inlet and positioned above an adjacent side of the liquid chemical container, whereby the airflow guides direct the filtered airflow to the area over the liquid chemical surface.

7. The air manager and chemical tank assembly of claim 1, wherein the liquid chemical tank is located beneath a deck in a semiconductor manufacturing clean room wet chemical processing station, wherein the airflow exhaust is located remotely from an upper edge of the liquid chemical tank opposite the filtered airflow source, and wherein the airflow exhaust inlet is defined by a space above the liquid chemical tank opposite the airflow source and below the deck, with an opening in the deck over the liquid chemical tank for ingress and egress of semiconductor manufacturing workpieces.

8. The air manager and chemical tank assembly of claim 7, further comprising a laminar downflow air source overlying the deck and chemical tank.

9. A wet station assembly of a semiconductor manufacturing facility, said wet station assembly comprising:

a deck having a liquid chemical tank positioned beneath the deck, with an opening in the deck over the liquid chemical tank for ingress and egress of semiconductor manufacturing workpieces;

a laminar downflow air source;

a below-deck exhaust for the wet station assembly; and

a below-deck airflow source positioned in relation to the exhaust to flow an airstream over a surface of liquid in the liquid chemical tank at a sufficient rate and in a sufficient volumetric flow to achieve Critical Capture Velocity (CCV) of vapor released from the liquid during operation of the wet station assembly.

10. The wet station assembly of claim 9, wherein the CCV is in the vicinity of 70 feet per minute.

11. The wet station assembly of claim 9, wherein the airflow source comprises an air plenum member, a purification medium in the air plenum member, and a motive air driver to induce flow of air through the plenum member for egress from the plenum member to flow across the liquid surface.

12. The wet station assembly of claim 11, wherein the airflow source comprises a chemisorbent medium for purification of influent air.

13. The wet station assembly of claim 9, further comprising airflow guide panels coupled with the plenum member and arranged to direct airflow therefrom across the liquid surface.

14. The wet station assembly of claim 9, further comprising a robotic wafer transport device arranged to introduce a semiconductor wafer into the liquid chemical tank for processing therein, and to remove the semiconductor wafer from the liquid chemical tank after processing therein.

15. A method of containing fumes emanating from a surface of a liquid in a liquid chemical tank, comprising:

providing a filtered airflow source and an airflow exhaust having an inlet constructed and arranged to receive said airflow;

positioning the filtered airflow source and the airflow exhaust inlet in relation to one another and to the tank, so that airflow from the filtered airflow source flows over the surface of the liquid in the liquid chemical tank to the airflow exhaust inlet; and

flowing an airflow from the filtered airflow source in a generally horizontal stream over the surface of the liquid chemical to the airflow exhaust inlet, whereby substantially all deleterious fumes emanating from the surface of the liquid are captured by and entrained in the airflow, and flow into the airflow exhaust.

16. The method of claim 15, further comprising confining the airflow to a region above the surface of the liquid by guide structures at sides of the tank.

17. A method of increasing the efficiency of the localized exhaust in exhausted equipment and systems within a semiconductor manufacturing clean room, comprising the steps of:

retrofitting the clean room to comprise an air manager and chemical tank assembly comprising;

a filtered airflow source that produces an airflow stream;

a liquid chemical tank, wherein a liquid contained within said liquid chemical tank produces fumes at said liquid'"'"'s surface, wherein said fumes are contained within said liquid chemical tank, and wherein said airflow stream is directed over said liquid'"'"'s surface to entrain said fumes; and

an airflow exhaust having an inlet for receiving said airflow stream with said entrained fumes, and wherein said airflow stream with said entrained fumes are transported to the exhaust.

18. A semiconductor fabrication facility clean room comprising:

a ceiling-to-floor laminar airflow system;

a set of exhaust equipment; and

at least one system comprising;

a liquid chemical tank for containing a liquid chemical composition producing fumes from a liquid surface thereof; and

an air manager assembly including a filtered airflow source and an airflow exhaust inlet arranged in facing relationship to one another at opposing sides of the liquid chemical tank above the liquid surface with the filtered airflow source and airflow exhaust inlet being constructed and arranged to maintain airflow across the surface of the liquid chemical from the filtered airflow source to the airflow exhaust inlet at an airflow velocity above the Critical Capture Velocity of chemical liquid fumes from the liquid chemical in said liquid chemical tank.

19. A method of operating a semiconductor fabrication facility clean room including a ceiling-to-floor laminar airflow system, and exhausted equipment and systems comprising a liquid chemical tank for containing a liquid chemical composition producing fumes from a liquid surface thereof, said method comprising the steps of:

providing a filtered airflow source and airflow exhaust inlet at opposite sides of the liquid chemical tank above the liquid surface; and

directing airflow across the liquid chemical surface from the filtered airflow source to the airflow exhaust inlet at an airflow velocity above the Critical Capture Velocity of chemical liquid fumes from the liquid chemical in said liquid chemical tank.

20. An air manager and chemical tank assembly, comprising:

a filtered airflow source that produces an airflow stream;

a liquid chemical tank, wherein a liquid contained within said liquid chemical tank produces fumes at said liquid'"'"'s surface, wherein said fumes are contained within said liquid chemical tank, and wherein said airflow stream is directed over said liquid'"'"'s surface to entrain said fumes; and

an airflow exhaust having an inlet for receiving said airflow stream with said entrained fumes, and wherein said airflow stream with said entrained fumes are transported to the exhaust.