JP2010056208A - Substrate cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate cleaning device capable of removing a metal contaminant and an organic contaminant accumulated in the device. <P>SOLUTION: The substrate cleaning device includes: a treatment chamber for cleaning a substrate by chemicals; a support tool for supporting the substrate in the treatment chamber; first piping for supplying the chemicals to the substrate in the treatment chamber; second piping for supplying a rinse liquid to the substrate in the treatment chamber; and a piping cleaning liquid supply system for supplying a piping cleaning liquid to at least one of the inside of the first piping and that of the second piping. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate cleaning apparatus for cleaning a substrate.

The film formation pattern conditions of a semiconductor substrate such as a silicon wafer are in the direction of miniaturization, and accordingly, various methods have been adopted for the cleaning technique to cope with the miniaturization.
However, it is a known fact that when cleaning a wafer, its surface is very active and it is very difficult to keep the cleaning surface for various reasons.
In addition, in a series of operations in which the wafer is cleaned with a cleaning solution such as an acid and dried through a rinsing process, it is necessary to deal with organic contamination in addition to metal contamination that has been regarded as a problem in the past. Organic substances brought together with the chemicals and pure water used in the system accumulate in the apparatus, and contamination is caused by this.

  When cleaning a semiconductor substrate in a substrate cleaning apparatus, mix one or more acids or alkalis (for example, hydrofluoric acid, hydrochloric acid, sulfuric acid, ammonia water, hydrogen peroxide water) and dilute with deionized water (DIW) (1) SC1 liquid: Ammonia water and hydrogen peroxide water mixed and diluted with DIW, SC2 liquid: hydrochloric acid and hydrogen peroxide water mixed and diluted with DIW, etc. and DIW called functional water with ozone gas and hydrogen What dissolved gas is used. Further, DIW, water in which carbon dioxide gas is dissolved, or the like is used as a rinsing liquid for replacing the chemical liquid. However, these raw materials are subject to organic contamination by piping materials from the supply tank to the point of use, and there is a problem that some of these materials are accumulated in the apparatus. In addition, the cleaning liquid, functional water, rinsing liquid, and the like for cleaning the semiconductor substrate are strictly controlled with respect to the amount of metal ions contained, but the management of organic substances is not so strict. Therefore, organic contamination due to redeposition of organic substances onto the semiconductor substrate becomes a problem in the entire cleaning process. Further, some chemical liquids / functional waters can remove these organic contaminations, but other chemical liquids / functional liquids cannot remove them, and organic substances accumulate inside the apparatus with use.

  An object of the present invention is to provide a substrate cleaning apparatus capable of removing metal contaminants and organic contaminants accumulated in the apparatus.

  According to one aspect of the present invention, a processing chamber that cleans a substrate with a chemical solution, a support that supports the substrate in the processing chamber, a first pipe that supplies the chemical solution to the substrate in the processing chamber, A second pipe for supplying a rinsing liquid to the substrate in the processing chamber; and a pipe cleaning liquid supply system for supplying a pipe cleaning liquid to at least one of the first pipe and the second pipe. A substrate cleaning apparatus is provided.

  According to the present invention, by creating a path for switching an oxidizing liquid such as hydrogen peroxide water or ozone water or an organic solvent such as IPA (isopropyl alcohol) in each pipe as necessary, Accumulated metal and organic contaminants can be removed.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a substrate cleaning apparatus according to an embodiment of the present invention.

  A DHF supply unit 14 for supplying DHF (dilute hydrofluoric acid), which is a chemical solution, into the substrate cleaning apparatus main body 12 is a pipe 14a, a first switching unit 15a, and a pipe that is a first pipe for supplying a chemical solution into the apparatus main body. It is connected to the apparatus main body 12 via 16a. The SC1 cleaning liquid supply unit 17 that supplies the SC1 liquid that is a chemical liquid is connected to the apparatus main body 12 via a pipe 17a, a second switching unit 15b, and a pipe 16b that is the first pipe. The SC2 cleaning liquid supply unit 18 that supplies the SC2 liquid that is a chemical solution is connected to the apparatus main body 12 via a pipe 18a, a third switching unit 15c, and a pipe 16c that is the first pipe.

  The DIW supply unit 20 that supplies DIW, which is a rinsing liquid, into the substrate cleaning apparatus main body 12 is provided via a pipe 20a, a fourth switching unit 15d, and a pipe 21, which is a second pipe that supplies the rinsing liquid into the apparatus main body. Connected to the apparatus body 12.

  An oxidizing cleaning liquid supply unit 22 that supplies an oxidizing cleaning liquid that is a pipe cleaning liquid into the substrate cleaning apparatus main body 12 includes a first switching unit 15a and a second switching unit via pipes 22a, 22b, 22c, and 22d. 15b, the third switching unit 15c, and the fourth switching unit 15d. Examples of the oxidizing cleaning liquid include an oxidizing liquid in which one or more of hydrogen peroxide water, ozone water, hypochlorous acid, nitric acid, chloramine, and dimethyl sulfoxide are mixed.

  An organic solvent cleaning liquid supply unit 24 that supplies an organic solvent cleaning liquid that is a pipe cleaning liquid into the substrate cleaning apparatus main body 12 includes a first switching unit 15a and a second switching unit via pipes 24a, 24b, 24c, and 24d. 15b, the third switching unit 15c, and the fourth switching unit 15d. Examples of the organic solvent cleaning liquid include organic solvents in which any one or more of methanol, ethanol, isopropyl alcohol, n-propyl alcohol, ethylene glycol, and 2-methyl-2-propanol are mixed.

  Therefore, the DHF supply unit 14 supplies DHF into the cleaning apparatus main body 12 via the pipe 14a, the first switching unit 15a, and the pipe 16a, and the first switching unit 15a is directed to the oxidizing cleaning liquid supply unit 22 side. By switching, the supply of DHF into the apparatus main body 12 is stopped, and the oxidizing cleaning liquid provided in the oxidizing cleaning liquid supply unit 22 passes through the pipe 22a, the first switching section 15a, and the pipe 16a. It is supplied into the main body 12. Further, the first switching unit 15a is switched to the organic solvent cleaning liquid supply unit 24 side, so that the organic solvent cleaning liquid provided in the organic solvent cleaning liquid supply unit 24 becomes the pipe 24a, the first switching unit 15a, and the pipe 16a. Is supplied to the inside of the apparatus main body 12.

  Further, the SC1 cleaning liquid supply unit 17 supplies the SC1 liquid into the cleaning apparatus main body 12 via the pipe 17a, the second switching unit 15b, and the pipe 16b, and the second switching unit 15b supplies the oxidizing cleaning liquid supply unit 22. The supply of the SC1 liquid into the apparatus main body 12 is stopped by switching to the side, and the oxidizing cleaning liquid provided in the oxidizing cleaning liquid supply section 22 passes through the pipe 22b, the second switching section 15b, and the pipe 16b. To be supplied into the apparatus main body 12. Further, the second switching unit 15b is switched to the organic solvent cleaning liquid supply unit 24 side, so that the organic solvent cleaning liquid provided in the organic solvent cleaning liquid supply unit 24 becomes the pipe 24b, the second switching unit 15b, and the pipe 16b. Is supplied to the inside of the apparatus main body 12.

  Further, the SC2 cleaning liquid supply unit 18 supplies the SC2 liquid into the cleaning apparatus main body 12 via the pipe 18a, the third switching unit 15c, and the pipe 16c, and the third switching unit 15c supplies the oxidizing cleaning liquid supply unit 22. The supply of the SC2 liquid into the apparatus main body 12 is stopped by switching to the side, and the oxidizing cleaning liquid provided in the oxidizing cleaning liquid supply section 22 passes through the pipe 22c, the third switching section 15c, and the pipe 16c. To be supplied into the apparatus main body 12. Further, the third switching unit 15c is switched to the organic solvent cleaning liquid supply unit 24 side, so that the organic solvent cleaning liquid provided in the organic solvent cleaning liquid supply unit 24 becomes the pipe 24c, the third switching unit 15c, and the pipe 16c. Is supplied to the inside of the apparatus main body 12.

  Further, the DIW supply unit 20 supplies DIW into the cleaning apparatus main body 12 through the pipe 20a, the fourth switching unit 15d, and the pipe 21, and the fourth switching unit 15d is connected to the oxidizing cleaning liquid supply unit 22 side. By switching, the supply of DIW into the apparatus main body 12 is stopped, and the oxidizing cleaning liquid provided in the oxidizing cleaning liquid supply unit 22 is supplied to the apparatus via the pipe 22d, the fourth switching unit 15d, and the pipe 21. It is supplied into the main body 12. In addition, the fourth switching unit 15d is switched to the organic solvent cleaning liquid supply unit 24 side, so that the organic solvent cleaning liquid provided in the organic solvent cleaning liquid supply unit 24 becomes the pipe 24d, the fourth switching unit 15d, and the pipe 21. Is supplied to the inside of the apparatus main body 12.

FIG. 2 shows the inside of the apparatus main body 12 of the substrate cleaning apparatus 10 according to the embodiment of the present invention.
A cleaning chamber 30 is configured by being surrounded by a substrate cleaning apparatus main body (cleaning container) 12. In this cleaning chamber 30, a support 34 for horizontally supporting a substrate 32 such as a semiconductor wafer is disposed. The support 34 is connected to a rotation mechanism 36 formed of a motor or the like via a rotation shaft 37, and the rotation mechanism 36 rotates the substrate 32 that is horizontally supported.

  The periphery of the support 34 is surrounded by a cover 38. As will be described later, the cover 38 receives a chemical solution that flies from the substrate 32 when the substrate 32 is rotated by the support 34.

  A substrate loading / unloading port 33 (see FIG. 1) is formed on the side surface of the apparatus body 12. The substrate loading / unloading port 33 is provided with a gate valve 35 (see FIG. 1). The gate loading / unloading port 33 opens and closes the substrate loading / unloading port 33. A substrate transfer machine 39 (see FIG. 1) for transferring the substrate 32 to the support 34 via the substrate carry-in / out port 33 is provided.

  A first nozzle 40 and a second nozzle 42 are inserted into the cleaning chamber 30 described above. The first nozzle 40 is connected to a first pipe (pipe 16a, 16b, 16c) that supplies chemical liquids such as DHF, SC1 liquid, and SC2 liquid, and the second nozzle 42 supplies rinsing liquid such as DIW. The first nozzle 40 and the second nozzle 42 are connected horizontally to the second pipe (pipe 21) so that their tips extend to near the center of the substrate 32 supported by the support 34. Has been placed. Therefore, the DHF, SC1 liquid, and SC2 liquid are supplied from the first nozzle 40 to the center of the substrate 32 through the first pipes 16a, 16b, and 16c. Further, DIW is supplied from the second nozzle 42 to the center of the substrate 32 through the pipe 21 that is the second pipe. Also, the first switching unit 15a, the second switching unit 15b, the third switching unit 15c, or the fourth switching unit 15d is switched to the oxidizing cleaning liquid supply unit side or the organic solvent cleaning liquid supply unit side. Then, an oxidizing cleaning liquid or an organic solvent cleaning liquid which is a pipe cleaning liquid is supplied into the pipes 16a, 16b, 16c or the pipe 21, and the substrate cleaning apparatus is supplied from both or at least one of the first nozzle 40 and the second nozzle 42. It is supplied into the main body 12.

  The water supply unit 50 is opened around the inner upper portion of the cover 38 described above, and can supply pure water (deionized water) to the inner surface of the cover 38.

  A drain pipe 54 for discharging pure water supplied to the cover 38 is connected to the lower surface of the cover 38, and the drain pipe 54 extends to the outside of the substrate cleaning apparatus body 12, and the drain pipe 54 is connected to the drain pipe 54. Then, the pure water in the cover 38 is discharged. Note that the chemical solution and the rinse solution supplied to the substrate 32 are also discharged through the drain pipe 54.

A drying gas supply pipe 56 is connected to the upper portion of the substrate cleaning apparatus main body 12. For example, nitrogen (N ₂ ) is used as the drying gas. Further, an exhaust pipe 60 for discharging the drying gas is connected to the lower part of the substrate cleaning apparatus main body 12.

The controller 62 is composed of a computer, and the rotation of the support 34 by the rotation mechanism 36, the opening and closing of the substrate loading / unloading port 33 by the gate valve 35, the loading and unloading of the substrate 32 by the substrate transfer machine 39, and the DHF by the first nozzle 40. , SC1 liquid, SC2 liquid supply, DIW supply by the second nozzle 42, supply of oxidizing cleaning liquid into the pipes 16a, 16b, 16c, 21 and organic solvent into the pipes 16a, 16b, 16c, 21 Supply of cleaning liquid, switching operation of first switching unit 15a, second switching unit 15b, third switching unit 15c and fourth switching unit 15d, supply of pure water from water supply unit 50, drying gas The supply of nitrogen (N ₂ ) from the supply pipe 56 is controlled.

  Next, a method for cleaning a substrate will be described as one step of a semiconductor device (device) manufacturing process using the substrate cleaning apparatus 10 having the above-described configuration.

FIG. 3 is a flowchart showing a control flow by the controller 62.
First, in step S <b> 10, the substrate loading / unloading port 33 is opened by the gate valve 35, and the substrate 32 on which the pattern is formed is loaded into the cleaning chamber 30 by the substrate transfer machine 39.

  In the next step S 12, the substrate transfer device 39 is further controlled to support (set) the substrate 32 on the support 34, and the substrate loading / unloading port 33 is closed by the gate valve 35.

  In the next step S <b> 14, the rotation of the substrate 32 is started by rotating the support 34 via the rotation shaft 37 by the rotation mechanism 36.

  In the next step S16, as shown in FIG. 4, the first switching unit 15a is switched to the DHF supply unit 14 side while maintaining the rotation of the substrate 32, and the first switching unit 15a is connected via the piping 16a which is the first piping. DHF is supplied from one nozzle 40 to clean the surface of the substrate 32. At this time, the second switching unit 15b may be switched to the SC1 cleaning liquid supply unit 17 side to supply the SC1 cleaning liquid from the first nozzle 40 via the pipe 16b, or the third switching unit 15c may be set to SC2. The SC2 cleaning liquid may be supplied from the first nozzle 40 via the pipe 16c by switching to the cleaning liquid supply unit 18 side.

  In the next step S18, as shown in FIG. 5, while the rotation of the substrate 32 is maintained, the supply of DHF from the first nozzle 40 is stopped, and the fourth switching unit 15d is moved to the DIW supply unit 20 side. The DIW as the rinsing liquid is supplied from the second nozzle 42 toward the center of the substrate 32 through the piping 21 that is the second piping, and the DHF remaining on the substrate surface is washed away to perform rinsing.

In the next step S20, as shown in FIG. 6, while the rotation of the substrate 32 is maintained, the supply of DIW from the second nozzle 42 is stopped, and the DIW or the like on the substrate is screened by the centrifugal force due to the rotation. . In this step S20, the cleaning chamber 30 is exhausted from the exhaust pipe 58 while supplying N ₂ as a drying gas via the drying gas supply pipe 56, and the cleaning chamber 30 is made an N ₂ atmosphere. _The substrate 32 is dried in _two atmospheres.
In addition, in order to improve safety, it is preferable to continuously supply water from the water supply unit 50 to the inner surface of the cover 38 from the cleaning process in step S16 or the rinsing process in step S18 to the drying process in step S20. That is, it is preferable to supply pure water to the inner surface of the cover 38 at least while DHF, DIW, etc. fly from the substrate 32 to the cover 38. In addition, it is preferable to supply pure water to the inner surface of the cover 38 also in a pipe cleaning process described later.

In the next step S <b> 22, the rotation of the substrate 32 is stopped by stopping the rotation of the support 34 by the rotation mechanism 36. Further, the supply of N ₂ into the cleaning chamber 30 is stopped.

  According to the next step S24, the substrate loading / unloading port 33 is opened by the gate valve 35, and the substrate 32 is unloaded from the cleaning chamber 30 by the substrate transfer device 39. Thereafter, the film is transferred to another apparatus, for example, an epitaxial growth apparatus, and processing such as film formation is performed.

  In the present invention, if necessary, for example, both the first switching unit 15a for supplying DHF and the fourth switching unit 15d for supplying DIW at times other than the series of substrate cleaning steps from Step S10 to Step S24 described above. Alternatively, at least one is switched to the oxidizing cleaning liquid supply unit 22 side. Then, an oxidizing liquid such as hydrogen peroxide water or ozone water is allowed to flow from the oxidizing cleaning liquid supply unit 22 so that the oxidizing liquid is piped as a first pipe through the first switching unit 15a. It can be made to flow into 16a and into piping 21 which is the 2nd piping via the 4th change part 15d. The oxidizing liquid that has flowed into the pipes 16 a and 21 is supplied into the cleaning apparatus main body 12 via the first nozzle 40 and the second nozzle 42, and is discharged from the drain pipe 54. Thereby, the organic matter accumulated in the first and second pipes, the first nozzle 40, the second nozzle 42, and the apparatus main body 12 can be oxidized and decomposed and discharged out of the system.

  Further, when the SC1 liquid or the SC2 liquid is used instead of DHF, the second switching unit 15b or the third switching unit 15c for supplying the SC1 liquid or the SC2 liquid is supplied with the oxidizing cleaning liquid as necessary. By switching to the unit 22 side and flowing an oxidizing liquid such as hydrogen peroxide water or ozone water from the oxidizing cleaning liquid supply unit 22, the oxidizing liquid is supplied to the second switching unit 15b or the third switching unit. It can flow through the pipe 16b or the pipe 16c which is the first pipe through the 15c. The oxidizing liquid that has flowed into the pipes 16 b and 16 c is supplied into the cleaning apparatus main body 12 through the first nozzle 40 and discharged from the drain pipe 54. Thereby, the organic matter accumulated in the first pipe, the first nozzle 40, and the apparatus main body 12 can be oxidized and decomposed and discharged out of the system.

When removing organic substances accumulated in the first and second pipes, the first nozzle 40, the second nozzle 42, and the cleaning apparatus main body 12, an organic solvent is used instead of the oxidizing cleaning liquid supply unit 22. A cleaning liquid supply unit 24 may be used.
By flowing the organic solvent through both or at least one of the first pipe and the second pipe, the first nozzle 40, the second nozzle 42, and the cleaning apparatus main body 12 are supplied. Organic matter accumulated inside can be directly dissolved and discharged out of the system.

  In addition, one or more of these two types of liquids (oxidizing liquid and organic solvent) are changed according to the respective pipes, or the contents and concentration are individually changed (for example, IPA and second pipes are used for the first pipe). Or methanol). However, when both an oxidizing liquid and an organic solvent are used in the pipe cleaning liquid supply system, it is necessary to replace the pipe with DIW during the cleaning process with each liquid, and it is also necessary to provide equipment for this purpose. .

  A small amount of phthalates and fluorine compounds added as plasticizers are eluted from pipes and valves that supply chemicals and DIW to the use point inside the equipment. In addition, organic compounds are eluted in a trace amount by piping and valves from the supply tank to the apparatus. These organic substances are accumulated in the tank wall and piping wall inside the apparatus, a slight dead space on the flow path, etc., re-eluted at another timing (effect of temperature, vibration, etc.) and adhere to the wafer being cleaned. The greatest feature of the present invention is that the organic matter accumulated in the apparatus can be discharged out of the system by self-cleaning the inside of the apparatus.

According to the present invention, by separately adding hydrogen peroxide water, ozone water, isopropyl alcohol, etc., which are different from the chemical solution originally used to the chemical solution or DIW piping, the organic pollutants accumulated in the apparatus are decomposed and dissolved. In addition, a cleaning process can be performed. In addition, this prevents organic contaminants from adhering to the wafer during wafer cleaning, keeps the wafer clean, and can be used for wafer cleaning prior to a film forming process sensitive to the degree of surface cleaning.
Hereinafter, preferred embodiments of the present invention will be additionally described.

  According to one aspect of the present invention, a processing chamber that cleans a substrate with a chemical solution, a support that supports the substrate in the processing chamber, a first pipe that supplies the chemical solution to the substrate in the processing chamber, A substrate having a second pipe for supplying a rinsing liquid to the substrate in the processing chamber, and a pipe cleaning liquid supply system for supplying a pipe cleaning liquid to at least one of the first pipe and the second pipe. A cleaning device is provided.

  Preferably, the chemical solution is a mixture of one or more acids or alkalis (for example, hydrogen fluoride, hydrochloric acid, sulfuric acid, ammonia water, hydrogen peroxide water) diluted with deionized water (DIW), or functional water. Ozone gas and hydrogen gas are dissolved in deionized water (DIW).

  Preferably, the chemical solution is dilute hydrofluoric acid (DHF), a mixture of ammonia water and hydrogen peroxide solution diluted with DIW (SC1), or a mixture of hydrochloric acid and hydrogen peroxide solution diluted with DIW (SC2). is there.

  Preferably, the rinse liquid is water in which carbon dioxide gas is dissolved.

  Preferably, the rinse liquid is deionized water (DIW).

  Preferably, the cleaning liquid is an oxidizing liquid in which one or more of hydrogen peroxide water, ozone water, hypochlorous acid, nitric acid, chloramine, and dimethyl sulfoxide are mixed.

  Preferably, the cleaning liquid is an organic solvent in which at least one of methanol, ethanol, isopropyl alcohol, n-propyl alcohol, ethylene glycol, and 2-methyl-2-propanol is mixed.

  Preferably, the concentration of the oxidizing liquid is 10% by weight or less.

  Preferably, the concentration of the oxidizing liquid is 1% by weight or less.

  Preferably, the concentration of the oxidizing liquid is 0.1% by weight or less.

  Preferably, the concentration of the oxidizing liquid is 0.01% by weight or less.

  Preferably, the concentration of the organic solvent is 10% by weight or less.

  Preferably, the concentration of the organic solvent is 1% by weight or less.

  Preferably, the concentration of the organic solvent is 0.1% by weight or less.

  Preferably, the concentration of the organic solvent is 0.01% by weight or less.

It is a lineblock diagram showing a substrate cleaning device concerning an embodiment of the present invention. It is sectional drawing which shows the inside of the apparatus main body of the board | substrate cleaning apparatus which concerns on embodiment of this invention. It is a flowchart which shows the control flow by the controller in embodiment of this invention. It is the top view and side view which show the state of the board | substrate washing | cleaning apparatus of the DHF washing | cleaning process in embodiment of this invention. It is the top view and side view which show the state of the board | substrate cleaning apparatus of the rinse process in embodiment of this invention. It is the top view and side view which show the state of the board | substrate cleaning apparatus of the drying process in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate cleaning apparatus 12 Substrate cleaning apparatus main body 14 DHF supply part 17 SC1 cleaning liquid supply part 18 SC2 cleaning liquid supply part 20 DIW supply part 22 Oxidative cleaning liquid supply part 24 Organic solvent cleaning liquid supply part 30 Cleaning chamber 32 Substrate 34 Support tool

Claims (1)

A processing chamber for cleaning the substrate with a chemical solution;
A support for supporting the substrate in the processing chamber;
A first pipe for supplying a chemical to the substrate in the processing chamber;
A second pipe for supplying a rinsing liquid to the substrate in the processing chamber;
A pipe cleaning liquid supply system for supplying pipe cleaning liquid to at least one of the first pipe and the second pipe;
A substrate cleaning apparatus comprising:

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