JP2009112947A - Manufacturing apparatus and manufacturing method of processing liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing apparatus of processing liquid capable supplying processing liquid not containing bubbles larger than nano bubbles. <P>SOLUTION: The manufacturing apparatus of processing liquid for manufacturing the processing liquid containing only nano bubbles, is provided with a nano bubble generator 5 generating minute bubbles in the processing liquid, a storage tank 1 storing the processing liquid containing bubbles made minute by the nano bubble generator, and a separation cage 2 and a centrifuge 23 separating and removing bubbles larger than nano bubbles among minute bubbles contained in the processing liquid stored in the storage tank. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a processing liquid manufacturing apparatus and a manufacturing method for miniaturizing bubbles contained in a processing liquid for processing, for example, a semiconductor wafer or a glass substrate of a liquid crystal cell.

  When manufacturing a semiconductor device or a liquid crystal display device, there is a lithography process in which a circuit pattern is formed on a substrate such as a semiconductor wafer or a glass substrate. In this lithography process, as is well known, a resist is applied to the substrate, and light is irradiated through a mask having a circuit pattern formed on the resist.

  Next, the portion of the resist not irradiated with light or the portion irradiated with light is removed, and the portion of the substrate where the resist is removed is etched. A circuit pattern is formed on the substrate by repeating a series of steps of removing the resist after etching a plurality of times.

  In such a lithography process, it is necessary to process the substrate with a developer, an etching solution or a stripping solution that removes the resist after etching, a step of cleaning with a cleaning solution, and a step of drying the substrate after cleaning. Become.

  Recently, the processing liquid is not simply pressurized with a pressurized gas, but the processing efficiency of the processing liquid is improved by making the gas into fine bubbles and mixing them in the processing liquid. Patent Document 1 discloses a processing apparatus in which processing efficiency is improved by mixing microbubbles in a processing liquid.

The processing apparatus shown in Patent Document 1 has a gas-liquid mixing pump into which pure water and nitrogen gas are introduced. Pure water and nitrogen gas are mixed in a gas-liquid mixing pump and sent to a turning accelerator constituting a microbubble generator. The turning accelerator accelerates and turns pure water and nitrogen gas, forms a gas-liquid two-layer flow, and sends it to the disperser. The disperser hydrodynamically shears the fed gas-liquid two-layer flow to form nitrogen gas microbubbles. And the pure water containing a microbubble is sent to a processing tank, and a board | substrate is processed.
JP 2006-179765 A

  By the way, the microbubble mentioned above is 10-100 micrometers in diameter, and is sufficiently fine compared with the bubble contained in a process liquid in the normal state. However, for example, it is a very large bubble as compared with a nanobubble having a diameter of 1 μm or less. If microbubbles having a large diameter stay on the surface of the substrate, the processing of the substrate by the processing liquid may be hindered. For example, when the processing liquid is an etching liquid, a stripping liquid, or a cleaning liquid, processing unevenness may occur due to bubbles remaining on the surface of the substrate, which is not preferable.

  Therefore, it is considered that bubbles contained in the processing liquid are made into finer nanobubbles than microbubbles to prevent processing unevenness due to the processing liquid. When the bubbles contained in the processing liquid are changed to nanobubbles, the swirl speed of the gas-liquid two-layer flow sent from the swirl accelerator of the microbubble generator shown in Patent Document 1 to the disperser is appropriately set, for example, the swirl speed difference is increased. By doing so, it is possible to increase the shear force that hydrodynamically shears the gas-liquid two-layer flow, thereby enabling the generation of nanobubbles.

  However, even if nanobubbles are generated in this way, not all of the gas contained in the gas-liquid two-layer flow becomes nanobubbles. For this reason, the processing liquid contains not only nanobubbles but also microbubbles or bubbles having a diameter larger than that, and thus processing irregularities may occur due to the microbubbles when the substrate is processed.

  The present invention provides a processing liquid manufacturing apparatus and a manufacturing method capable of efficiently separating and removing bubbles having a diameter larger than that of nanobubbles when bubbles of various sizes are included in the processing liquid. There is.

The present invention is a processing liquid manufacturing apparatus for producing a processing liquid containing only nanobubbles,
Fine bubble generating means for generating fine bubbles in the treatment liquid;
A liquid storage tank for storing the processing liquid containing bubbles,
An apparatus for producing a treatment liquid, comprising: a bubble separation means for separating bubbles larger than nano bubbles among the bubbles contained in the treatment liquid stored in the liquid storage tank.

  It is preferable that the bubble separation means is a separation basket formed of a porous material provided in the liquid storage tank so as to be movable up and down and having a peripheral wall passing only the nanobubbles.

  The liquid storage tank is preferably provided with a heating means for heating the processing liquid stored in the liquid storage tank.

  The bubble separation means is preferably a centrifugal separator that applies a centrifugal force to the processing liquid stored in the liquid storage tank and separates bubbles larger than the nanobubbles contained in the processing liquid by the centrifugal force. .

This invention is a method for producing a treatment liquid for producing a treatment liquid containing only nanobubbles,
Generating fine bubbles in the treatment liquid;
A step of storing a treatment liquid containing finely-sized bubbles;
And a step of separating bubbles that are larger than nanobubbles among the micronized bubbles contained in the stored processing solution.

  According to the present invention, if the bubbles contained in the treatment liquid are refined, bubbles larger than the nano bubbles can be separated and removed from the bubbles contained in the treatment liquid. It becomes possible to supply.

  An embodiment of the present invention will be described below with reference to the drawings.

  The processing liquid manufacturing apparatus shown in FIG. 1 includes a liquid storage tank 1. In the liquid storage tank 1, a separation tank 2 constituting a first bubble separation means is provided. The separation rod 2 is formed in a box shape having an open upper surface, and can be driven in the vertical direction indicated by an arrow by vertical drive means 3 such as a linear motor or a cylinder.

  The separation tank 2 of the liquid storage tank 1 is supplied with a treatment liquid L in which bubbles are refined by a nanobubble generator 5 as a fine bubble generating means described later. The peripheral wall of the separation basket 2, in this embodiment, the bottom of the peripheral wall, allows passage of nanobubbles having a diameter of 1 μm or less among the bubbles contained in the treatment liquid L, and microbubbles having a diameter of 10 to 100 μm or more. For example, the porous member 2a is formed of a material such as ceramic and has a fine pore size that prevents passage of bubbles having a size of.

  As shown in FIG. 2, the nanobubble generator 5 has a hollow main body 7 in which a shear chamber 6 is formed. One end of the shear chamber 6 communicates with an injection port 8 formed on the front end surface of the main body 7 in the axial direction, and the other end communicates with a gas supply port 9 formed on the rear end surface of the main body 7.

  The shear chamber 6 includes a frustum-shaped rear space 6a whose diameter increases from the rear end communicating with the gas supply port 9 toward the middle of the rear end, and gradually from the rear space 6a toward the front. Is formed by a truncated cone-shaped front space portion 6b having a reduced diameter, and a boundary portion between the rear space portion 6a and the front space portion 6b of the shear chamber 6 is formed on the outer peripheral surface of the main body 7. An open liquid supply port 10 is formed.

  The gas supply port 9 is provided with a gas swivel base 11. The other end of the gas supply pipe 13 whose one end is connected to the gas supply pump 12 is connected to the gas turning base 11. A first on-off valve 14 is provided in the middle of the gas supply pipe 13. The suction side of the gas supply pump 12 is connected to a gas supply source such as a high-pressure cylinder (not shown). This gas supply source supplies, for example, oxygen as a gas.

  Although details of the gas swivel base 11 are not shown, the gas swivel base 11 has a spiral groove formed therein. Accordingly, when the first on-off valve 14 is opened, the oxygen supplied from the gas supply pump 12 through the gas supply pipe 13 is swirled to move from the rear space portion 6a to the front space portion 6b of the shear chamber 6. The oxygen gas cavity 15 is formed in the shear chamber 6 as shown by a chain line in FIG. In this embodiment, the spiral groove of the gas turning base 11 turns the gas in a counterclockwise direction when viewed from the rear end side of the main body 7. The swirling direction of the gas is indicated by an arrow a in FIG.

  In the liquid supply port 10, a liquid supply base 16 is inclined clockwise at an angle θ 1 as shown in FIG. 3 with respect to the circumferential direction of the main body 7, and as shown in FIG. Inclined at an angle of θ2 toward the side.

  The liquid supply base 16 is connected to the other end of a liquid supply pipe 18 having one end connected to a liquid supply pump 17. A second on-off valve 19 is provided in the middle of the liquid supply pipe 18. The suction side of the liquid supply pump 17 is connected to a supply source (not shown) of the liquid that is the processing liquid L, for example, pure water.

  Accordingly, when the second on-off valve 19 is opened, the processing liquid L is supplied to the nanobubble generator 5 by the liquid supply pump 17 through the liquid supply pipe 18. The treatment liquid L supplied to the nanobubble generator 5 is swung counterclockwise in the same manner as the oxygen by the inclination angle θ1 of the liquid supply base 16, and the front space is provided by the inclination angle θ2 of the liquid supply base 16. It flows in the direction of traveling toward the part 7b.

  The supply pressure of oxygen is set to P1 by the gas supply pump 12, and the supply pressure of the processing liquid L is set to P2 by the liquid supply pump 17. P1 <P2 is set. Thereby, the relationship between the swirl speed V1 of oxygen supplied to the shear chamber 6 of the main body 7 and the swirl speed V2 of the treatment liquid L is V1 <V2.

  In this embodiment, the oxygen supply pressure P1 and the process liquid L supply pressure P2 are set so that the oxygen swirl speed V1 is 400 revolutions per second and the process liquid L swirl speed V2 is 600 revolutions per second.

  Oxygen supplied from the axial rear end of the shear chamber 6 becomes a gas cavity 15 that swirls as shown by an arrow a and travels toward the injection port 8. The treatment liquid L supplied from the outer peripheral surface of the shear chamber 6 advances toward the injection port 8 while swirling the outer peripheral surface of the swirling oxygen gas cavity 15. The swirling direction of the processing liquid is indicated by an arrow b in FIG.

  The oxygen turning speed V1 is set to be slower than the turning speed V2 of the processing liquid L. For this reason, oxygen is hydrodynamically sheared by the treatment liquid L due to the difference in swirling speed between oxygen and the treatment liquid L, and oxygen nanobubbles are generated by the shearing action. The treatment liquid L containing oxygen nanobubbles is ejected from the ejection port 8 at the tip of the shear chamber 6.

  When nanobubbles are generated by the difference in swirling speed between oxygen and the treatment liquid L, the same shear force does not act hydrodynamically on all the gases forming the gas cavity 15, and therefore the injection port 8. The processing liquid L sprayed from the liquid and supplied to the liquid storage tank 1 includes not only nanobubbles but also microbubbles having a diameter larger than nanobubbles, or bubbles larger than that.

  The processing liquid L in which the gas is converted into nanobubbles by the nanobubble generator 5 is supplied from the injection port 8 to the inside of the separation tank 2 through the first processing liquid supply pipe 20. When the treatment liquid L is sufficiently accumulated in the liquid storage tank 1 through the separation tank 2, the separation tank 2 is driven in the upward direction by the vertical drive means 3.

  Nanobubbles contained in the treatment liquid L have a smaller buoyancy than microbubbles. As a result, the microbubbles float above the processing liquid L, but the nanobubbles do not float but stay in the processing liquid L. Moreover, the bottom wall of the separation rod 2 is formed by a porous member 2a having micropores that allow only nanobubbles to pass therethrough.

  Therefore, when the separation basket 2 is raised, the microbubbles in the separation basket 2 float up in the processing liquid L and are diffused to the atmosphere. However, since the microbubbles are fine, there is almost no buoyancy. Without floating inside, it passes through the micropores of the lower porous member 2a of the separation rod 2 and flows out to the outside.

  One end of a second processing liquid supply pipe 21 is connected to the bottom of the liquid storage tank 1. The other end of the second processing liquid supply pipe 21 is connected to the suction side of the processing liquid supply pump 22, and a centrifuge 23 as second bubble separation means is connected to the discharge side of the processing liquid supply pump 22. Are connected by one connecting pipe 24.

  The centrifuge 23 has a separator body 25 as shown in FIG. The separator body 25 is hollow and includes a conical portion 25a and a columnar portion 25b connected to the large diameter portion of the conical portion 25a. A supply port body 26 is provided on the peripheral wall on the small diameter portion side of the conical portion 25 a, and the first connection pipe 24 is connected to the supply port body 26.

  A first discharge port body 27 is connected to the peripheral wall of the cylindrical portion 25b, and a second discharge port body 28 is connected to the end surface. One end of a second connection pipe 29 is connected to the first discharge port body 27, and the other end of the second connection pipe 29 is used for processing a substrate (not shown) such as a semiconductor wafer or a glass substrate for liquid crystal display. Connected to the processing device 31. One end of a return pipe 32 is connected to the second connection pipe 29, and the other end of the return pipe 32 communicates with the liquid storage tank 1.

  The processing liquid L supplied from the processing liquid supply pump 22 to the supply port body 26 of the centrifuge 23 at a predetermined pressure swirls and flows through the conical part 25a and the cylindrical part 25b in the separator body 25. . When centrifugal force is generated by swirling the processing liquid L, nanobubbles having a high specific gravity among the nanobubbles and microbubbles contained in the processing liquid L are placed on the outer periphery of the swirling flow as indicated by a chain line arrow A in FIG. It moves and swirls along the inner peripheral surface of the separator body 25, and the microbubbles having a low specific gravity flow toward the second discharge port body 28 at the center of the swirling flow as indicated by an arrow B.

  Thereby, the processing liquid containing nanobubbles is discharged from the first discharge port body 27 and supplied to the processing apparatus 31 through the second connection pipe 29. The processing liquid L containing microbubbles is discharged from the second discharge port body 28 and returned to the liquid storage tank 1 through the return pipe 29.

  As a result, the processing liquid L discharged from the first discharge port body 27 of the centrifugal separator 23 performs an appropriate process on the substrate provided in the processing apparatus 31. The treatment liquid L returned to the liquid storage tank 1 by the return pipe 29 is preferably returned to the inside of the separation tank 2, but may be returned to the outside of the separation tank 2.

  That is, if a separation bubble 2 as a first bubble separation means is provided in the liquid storage tank 1 to capture microbubbles, and there are microbubbles that flow out to the outside without being captured by the separation tank 2, the microbubbles The bubbles were separated from the nanobubbles by the centrifuge 23 as the second bubble separation means, and the processing liquid L was supplied to the processing apparatus 31 so that only the nanobubbles were included. That is, the processing liquid L discharged from the centrifuge 23 and supplied to the processing apparatus 31 includes only nanobubbles and does not include microbubbles.

  A heater 34 as a heating means is provided on the outer bottom surface of the liquid storage tank 1. The heater 34 heats the processing liquid L stored in the liquid storage tank 1. When the treatment liquid L is heated, the buoyancy of microbubbles having a large diameter among the bubbles contained in the treatment liquid L increases. As a result, the microbubbles contained in the processing liquid L are likely to rise, so that the microbubbles are easily lost from the processing liquid L, and the processing liquid L supplied to the centrifuge 23 by the processing liquid supply pump 22 is also increased. The amount of microbubbles contained in can be reduced.

  That is, the heater 34 as a heating unit functions as a third bubble separation unit that removes microbubbles from the processing liquid L together with the separation basket 2 and the centrifugal separator 23. Accordingly, the heater 34 may be used in place of the separator 2 and the centrifugal separator 23 as the bubble separating means.

  If the processing liquid L produced by the manufacturing apparatus having such a configuration is supplied to the substrate processing apparatus 31 to process the substrate, the processing liquid L does not contain microbubbles but only nanobubbles having a fine diameter. Is included.

Since only the nanobubbles are contained in the processing liquid L, the surface tension of the processing liquid L is reduced and the surface active effect is improved. In addition, it is possible to prevent uneven cleaning as in the case of including microbubbles.
Even when the processing liquid L is an etching liquid or a developer, the processing effect can be improved and the occurrence of processing unevenness can be prevented as in the case of the cleaning liquid.

In the one embodiment, among the nanobubbles and microbubbles contained in the treatment liquid, as a bubble separation means for separating and removing microbubbles, a separation tank is provided in the storage tank, and a centrifuge is provided outside the storage tank, The microbubbles contained in the treatment liquid are separated and removed by both of them, but the microbubbles contained in the treatment liquid may be separated and removed only by either one of the separation tank and the centrifuge.
When only the centrifuge is used as the bubble separation means, the nanobubble generator may be provided inside the liquid storage tank.

  In addition, the porous member is provided only at the bottom of the peripheral wall of the separation rod, but at least one of the bottom and the side wall may be a porous member.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the manufacturing apparatus of the process liquid which shows one embodiment of this invention. Sectional drawing of a nano bubble generator. The side view which looked at the nano bubble generator from back. The perspective view of a centrifuge.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid storage tank, 2 ... Separation tank (1st bubble separation means), 2a ... Porous member, 5 ... Nano bubble generator (bubble refinement | miniaturization means), 23 ... Centrifugal separator (2nd bubble separation means) , 26 ... heater (heating means).

Claims (5)

A processing liquid production apparatus for producing a processing liquid containing only nanobubbles,
Fine bubble generating means for generating fine bubbles in the treatment liquid;
A liquid storage tank for storing the processing liquid containing bubbles,
An apparatus for producing a treatment liquid, comprising: bubble separation means for separating bubbles larger than nanobubbles among the bubbles contained in the treatment liquid stored in the liquid storage tank.   2. The treatment liquid according to claim 1, wherein the bubble separation means is a separation tank which is provided in the liquid storage tank so as to be movable up and down and whose peripheral wall is formed by a porous member that passes only the nanobubbles. Manufacturing equipment.   2. The processing liquid manufacturing apparatus according to claim 1, wherein the liquid storage tank is provided with heating means for heating the processing liquid stored in the liquid storage tank.   The bubble separation means is a centrifugal separator that applies a centrifugal force to the treatment liquid stored in the liquid storage tank, and separates bubbles larger than the nanobubbles contained in the treatment liquid by the centrifugal force. The apparatus for producing a treatment liquid according to claim 1. A process liquid manufacturing method for producing a process liquid containing only nanobubbles,
Generating fine bubbles in the treatment liquid;
A step of storing a treatment liquid containing finely-sized bubbles;
And a step of separating bubbles larger than the nanobubbles among the micronized bubbles contained in the stored processing solution.

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