JP2009270825A - Sampling tube and sampling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sampling tube and a sampling method capable of sampling a liquid under no influence of bubbles in solution; and a cleaning device and a cleaning method using the sampling tube. <P>SOLUTION: The sampling tube is immersed in a liquid 2 to sample the liquid and has a complex tube configuration that an inside sampling inner tube 3 is surrounded by a sampling outer tube 10 having a closed bottom and provided with an inlet to flow in the liquid. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid sampling tube and a sampling method, and a cleaning apparatus and a cleaning method using the sampling tube, and in particular, a sampling tube and a sampling method for sampling a chemical solution that requires constant management of a chemical concentration, and the sampling thereof. The present invention relates to a cleaning apparatus and a cleaning method using a tube.

  One of the processes for manufacturing a semiconductor substrate (hereinafter referred to as “wafer”) is a process of cleaning the wafer with a mixed chemical solution whose concentration is controlled. The chemical solution used for cleaning is sampled from the processing tank, measured with an automatic concentration measuring device, and the measurement result is fed back to maintain the chemical concentration. This is because feedback supplementation of the cleaning reagent is required to maintain the chemical concentration.

  An example of an apparatus that performs cleaning while sampling the cleaning liquid and measuring the contents in the cleaning liquid is disclosed in Patent Document 1. Further, Patent Document 2 discloses an ultrasonic cleaning system that controls the oscillation output of ultrasonic waves by measuring the amount of bubbles in the cleaning liquid. Patent Document 3 discloses an apparatus for removing bubbles mixed in the pipe.

JP 2003-215002 A JP 2007-326088 A JP 2000-126507 A

  When sampling a chemical solution, bubbles are mixed in the solution, so if you measure the liquid directly with bubbles mixed in, for example, a concentration meter that measures the amount of light that has passed through the solution, the concentration of the chemical solution is accurate. May not be measured. Therefore, in a system that feeds back a reagent based on the measurement result, the concentration maintenance may become unstable, or even in an abnormal concentration range, it may be determined to be normal and cleaning may be insufficient.

  The apparatus or method described in Patent Document 1 or 2 does not disclose a method for preventing the analyzer from being affected by bubbles in the liquid. In the apparatus described in Patent Document 3, bubble separation by bubble buoyancy is disclosed, but microbubbles are trapped by a mesh, and such a mesh needs to be cleaned and replaced due to clogging or the like.

  In the first aspect, the sampling tube according to the present invention, which is immersed in a liquid and samples the liquid, is a sampling inner pipe for sucking the liquid, the bottom is closed, and the flow into which the liquid flows The composite pipe structure is characterized by being surrounded by a sampling outer pipe provided with an inlet.

  In a second aspect, the sampling method according to the present invention, in which the liquid is sampled by being immersed in the liquid, the inner pipe for sampling for sucking the liquid is closed and the flow into which the liquid flows A sampling tube surrounded by a sampling outer tube provided with an inlet and having a composite tube structure is used.

  In the third aspect, the cleaning apparatus according to the present invention for cleaning an article while constantly sampling and measuring the concentration of a substance in the cleaning liquid samples the cleaning liquid using the sampling tube according to any one of the above. It is characterized by.

  In a fourth aspect, the cleaning method according to the present invention for cleaning an article while constantly sampling and measuring the concentration of a substance in the cleaning liquid samples the cleaning liquid using the sampling method according to any one of the above. It is characterized by that.

  According to the present invention, bubbles can be prevented from being mixed when sampling a liquid, the influence of bubbles on concentration measurement can be ignored, and the concentration of the sampled chemical solution can be accurately measured. Therefore, it is possible to reduce cleaning failures due to abnormal chemical concentration, and to reduce cases where the concentration value is judged to be abnormal even though the concentration value is normal, thereby improving the equipment operating rate.

  The sampling outer tube of the sampling tube according to the present invention has a length that extends above the liquid level of the liquid, and is provided with a liquid inlet on the wall surface below the liquid level.

  In addition, the sampling outer tube of the sampling tube according to the present invention has a length that extends below the liquid level of the liquid, and the liquid inlet can be the upper end surface of the sampling outer tube.

  The inlet of the sampling outer tube is preferably arranged at least 50 mm above the liquid suction port of the sampling inner tube.

  Furthermore, the number of outer tubes for sampling can be at least two. By doing so, the influence of bubbles on the analysis can be further reduced.

  The outer tube for sampling of the sampling tube used in the sampling method according to the present invention has a length that extends above the liquid level of the liquid, and has a liquid inlet on the wall surface below the liquid level. Provide.

  Further, the sampling outer tube of the sampling tube used in the sampling method according to the present invention has a length that extends below the liquid level of the liquid, and the liquid inlet is the upper end surface of the sampling outer tube. be able to.

  In addition, the inlet of the sampling outer tube of the sampling tube used in the sampling method according to the present invention is preferably arranged at least 50 mm above the liquid suction port of the sampling inner tube.

  Moreover, the sampling outer tube of the sampling tube used in the sampling method according to the present invention can be at least two. By doing so, the influence of bubbles on the analysis can be further reduced.

Example 1
FIG. 1 shows an embodiment of the present invention for a cleaning apparatus that needs to sample and appropriately measure the chemical concentration in a chemical liquid (cleaning liquid) 2 in a chemical liquid tank (cleaning tank) 1 as in the case of immersion cleaning of a wafer. It is the schematic of the washing | cleaning apparatus 30 to which the sampling tube concerning this is applied (the wafer in a chemical | medical solution is not shown in figure). The liquid sampled by the sampling inner tube 3 and the sampling outer tube 10 is measured by the concentration measuring device 4, and when the chemical concentration drops below a predetermined value, the valve provided in the reagent pipe 5 is automatically opened and closed. Then, the reagent is supplied to the chemical tank 1 to keep the chemical concentration at a predetermined value. When the impurities in the chemical liquid 2 finally increase, the chemical liquid 2 is drained through the drain pipe 6.

  FIG. 2 is a cross-sectional schematic view of a conventional sampling tube installed in a chemical tank and a sampling tube according to the present invention. FIG. 2A is a cross-sectional view of a conventional sampling tube. FIG. 2 (b) shows a sampling tube according to the present invention, which has a double tube structure having a sampling inner tube 3 for sucking a liquid and a sampling outer tube 10 around the same as a conventional sampling tube. Yes.

  FIG. 3A is an enlarged view of a portion surrounded by a dotted line in FIG. The sampling outer tube 10 is closed at the bottom, and has a chemical solution inlet 11 for allowing the chemical solution to flow into the side wall thereof. The upper end of the sampling outer tube 10 is opened so that bubbles are released. Usually, it opens to the internal space of the chemical tank 1 (see FIG. 2B). The chemical solution in the chemical solution tank flows into the inside from the chemical solution intake port 11 and is sucked from the suction port 3a which is the outermost end portion of the sampling inner tube 3.

  In this way, the chemical solution containing bubbles flows into the inside from the chemical solution intake port 11 of the sampling outer tube 10 and passes through between the double tubes to reach the suction port 3a of the sampling inner tube 3 only. As a result of buoyancy, the bubbles are separated.

  The dimensions of the double tube structure need to be set so that bubbles that affect the concentration measuring device 4 are sufficiently separated while the chemical solution 2 basically passes between the double tubes. In other words, the interval between the double tubes is considered in consideration of the sampling flow rate so that the speed at which the drug solution 2 moves between the double tubes is slower than the speed at which bubbles of a size that affect the analysis rise. Area).

  For example, in the case of a sampling tube for analyzing the concentration of a chemical solution in a cleaning tank for cleaning a wafer, the sampling inner tube 3 has a diameter of about 6 to 12 mm and a wall thickness of about 1 mm, and the sampling outer tube 10 has a diameter. Is preferably about 12 to 19 mm and a thickness of about 1 mm. In the first embodiment, the inner pipe and the outer pipe are circular pipes, but they are not necessarily circular pipes for that purpose.

  FIG. 4 is a front view showing an example of the arrangement and shape of the chemical liquid inlet 11. The chemical solution inlet 11 may be disposed anywhere as long as it does not interfere with the wafer, but is preferably disposed at a position close to the inner wall side of the chemical solution tank 1. The height H of the sampling inner tube 3 from the suction port 3a is preferably about 50 mm or more in order to avoid sucking bubbles as much as possible (see FIG. 4).

  The size and shape of the chemical solution inlet 11 may be any shape as long as the chemical solution 2 can sufficiently flow in. For example, a hole having a diameter of about 2 mm (see FIG. 4A) or a long hole having a size of about 2 mm × 20 mm. (See FIG. 4B).

  The sampling outer tube 10 may be integrated with the sampling inner tube 3, or if the sampling inner tube 3 can be accurately positioned, the sampling outer tube 10 is previously placed on the inner wall of the chemical solution tank 1. And the sampling inner tube 3 may be inserted later.

  In the first embodiment, the sampling tube according to the present invention is used for the chemical management of the chemical tank in the immersion type cleaning apparatus, but this sampling is performed in the chemical adjustment tank for mixing and adjusting the chemical liquid to be supplied to the cleaning apparatus. It goes without saying that tubes can be applied.

(Example 2)
FIG. 3B is a schematic cross-sectional view showing a second embodiment of the sampling tube according to the present invention. In the second embodiment, a second sampling outer tube 20 is further provided outside the sampling outer tube 10, and two sampling outer tubes are combined. Similarly, the second sampling outer tube 20 is provided with a chemical solution inlet 21. By multiplexing the sampling outer tubes in this manner, it is possible to further reduce the mixing of bubbles into the concentration meter.

(Example 3)
In the first embodiment, the sampling outer tube 10 is made longer than the liquid level. This is to separate the rising bubble passage and the chemical solution inflow path as much as possible and to eliminate the effect of bubbles floating on the chemical liquid surface, but the influence of such a liquid surface can be ignored or a sufficiently long separation time. If it can be ensured, it is conceivable to arrange the entire sampling outer tube 10 below the liquid level.

  FIG. 5 is a schematic cross-sectional view of Example 3 in which the entire sampling outer tube 10 is disposed below the liquid level. In this case, since the chemical solution flows in from the upper end portion of the sampling outer tube 10, the chemical solution intake port becomes the upper end portion of the sampling outer tube 10.

  Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the configurations of the above-described embodiments, and various modifications that can be made by those skilled in the art within the scope of the present invention. Of course, including modifications.

It is the schematic of the washing | cleaning apparatus using the sampling tube which concerns on this invention. (A) It is a cross-sectional schematic diagram of the conventional sampling tube installed in the chemical | medical solution tank. (B) It is the cross-sectional schematic which shows the 1st Example of the sampling tube concerning this invention installed in the chemical | medical solution tank. (A) It is an enlarged view of the part A enclosed with the dotted line of FIG.2 (b). (B) It is a section schematic diagram showing the 2nd example of a sampling tube concerning the present invention. The example of arrangement | positioning and shape of the chemical | medical solution intake of the outer tube | pipe of the sampling tube which concerns on this invention is shown. FIG. 6 is a schematic cross-sectional view showing a third embodiment of the sampling tube according to the present invention.

Explanation of symbols

1 Chemical tank (cleaning tank)
2 Chemical liquid (cleaning liquid)
3 Sampling inner tube 3a Suction port 4 Concentration measuring device (also valve control device)
5 Reagent pipe 6 Drain pipe 10, 20 Sampling outer pipe 11, 21 Chemical solution inlet 30 Cleaning device

Claims (12)

A sampling tube that is immersed in a liquid to sample the liquid,
Sampling characterized in that a sampling inner pipe for sucking the liquid has a closed pipe and is surrounded by a sampling outer pipe provided with an inflow port through which the liquid flows to form a composite pipe structure tube.   The sampling outer tube has a length that extends above the liquid level of the liquid, and the liquid inlet is provided on a wall surface below the liquid level. The sampling tube according to claim 1.   The sampling outer tube has a length extending to a level below a liquid level of the liquid, and the inlet of the liquid is an upper end surface of the sampling outer tube. The sampling tube according to 1.   The sampling tube according to any one of claims 1 to 3, wherein the inlet of the sampling outer tube is disposed at least 50 mm above the liquid suction port of the sampling inner tube. .   The sampling tube according to claim 1, wherein the number of the outer sampling tubes is at least two. A sampling method for sampling the liquid by dipping in the liquid,
The sampling tube for sucking the liquid is characterized by using a sampling tube having a composite tube structure surrounded by a sampling outer tube having a bottom closed and an inflow port through which the liquid flows. Sampling method.   The sampling outer tube has a length that extends above the liquid level of the liquid, and the liquid inlet is provided on a wall surface below the liquid level. The sampling method according to claim 6.   The sampling outer tube has a length extending to a level below a liquid level of the liquid, and the inlet of the liquid is an upper end surface of the sampling outer tube. 7. The sampling method according to 6.   The sampling method according to any one of claims 6 to 8, wherein the inlet of the sampling outer tube is disposed at least 50 mm above the liquid suction port of the sampling inner tube. .   The sampling method according to claim 6, wherein there are at least two sampling outer tubes.   A cleaning apparatus for cleaning an article while constantly sampling and measuring a substance concentration in the cleaning liquid, wherein the cleaning liquid is sampled using the sampling tube according to any one of claims 1 to 5. A cleaning device.   A cleaning method for cleaning an article while constantly sampling and measuring a substance concentration in the cleaning liquid, wherein the cleaning liquid is sampled using the sampling method according to any one of claims 6 to 10. Cleaning method.

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