JP2002353186A - Liquid chemical recycling system for sheet substrate- cleaning device and sheet substrate-cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid chemical recycling technique, capable of efficiently recycling a liquid chemical in relation with a cleaning process cycle in sheet wet cleaning. SOLUTION: A liquid chemical supply and recovery part 30 is provided with two storage tanks 35 and 36 storing the liquid chemical and a liquid chemical circulation part 37 circulating the liquid chemical of the storage tanks 35 and 36, through a density correction part 31 and performing purification. While the liquid chemical of one storage tank 35 or 36 is supplied to a cleaning chamber 3 and used and cleaning is executed, the liquid chemical of the other storage tank 36 or 35 is circulated in the liquid chemical circulation part 37, purified and density-corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical liquid recycling system for a single-wafer type substrate cleaning apparatus and a single-wafer type substrate cleaning apparatus, and more particularly, to wet cleaning of substrates such as semiconductor wafers one by one with a chemical liquid. The present invention relates to a chemical liquid recycling technique for collecting and reusing used chemical liquids in a single wafer type wet cleaning apparatus.

[0002]

2. Description of the Related Art Conventionally, as a method of wet cleaning a substrate such as a semiconductor wafer (hereinafter simply referred to as a wafer), a carrier is conventionally used for a wet bench type cleaning tank in which a plurality of cleaning tanks are continuously arranged. So-called batch type wet cleaning, in which a plurality of wafers stored in a cassette or a plurality of wafers are directly immersed by a transfer device without a carrier cassette and processed, was the mainstream, but semiconductor devices were also in the submicron era. With the recent miniaturization and high integration of such device structures, very high cleanliness is also required on the wafer surface.In recent years, as a wet cleaning technology that satisfies the demand for higher cleanliness, A so-called single wafer wet cleaning in which wafers are wet-cleaned one by one in a sealed cleaning housing without a cassette has been developed.

[0003] In this single wafer type wet cleaning, cleaning in a high cleanness atmosphere can be performed with high precision without reattachment of particles, etc. In addition, the apparatus configuration is simple and compact, and it is possible to produce many kinds of small quantities. Also has the advantage of being able to respond effectively.

[0004]

In the single-wafer wet cleaning, the surface of the wafer is cleaned with various chemicals in a predetermined order. In general, used chemical liquids are generally directly subjected to waste liquid treatment in order to prevent the occurrence of the cleaning and to perform high-precision cleaning.

On the other hand, recently, due to demands for resource saving and the like, as in the case of batch-type wet cleaning in which a large amount of chemical liquid is used in one cleaning step, used chemical liquid is collected as it is without waste liquid treatment. Various chemical liquid recycling technologies for purifying the chemical liquid, correcting the concentration, and then reusing the same have been proposed and developed. However, there is room for further improvement in any of the recycling techniques.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to efficiently reuse a chemical solution in a single wafer wet cleaning in relation to a cleaning process cycle. It is an object of the present invention to provide a chemical solution recycling technology that can realize the above.

[0007]

In order to achieve the above object, a chemical liquid recycling system according to the present invention collects used chemical liquid in a single-wafer substrate cleaning apparatus that performs wet cleaning of wafers one by one with a chemical liquid. A chemical solution recycling system for supplying and recovering a cleaning chemical solution to and from the cleaning chamber of the single-wafer cleaning apparatus, and a concentration correction unit for correcting the concentration of the chemical solution in the chemical solution supply / collection unit. The chemical solution supply and recovery unit includes a plurality of storage tanks for storing the chemical solution, and a chemical solution circulating unit for circulating the chemical solution in these storage tanks through the concentration correction unit and performing a cleaning process, The plurality of storage tanks can be selectively connected to the chemical circulation section.

In a preferred embodiment, while any one of the plurality of storage tanks is being supplied to the cleaning chamber and used, the other remaining storage tanks are circulated in the chemical circulation section. It is configured so as to be cleaned and density corrected.

When the chemical supply / recovery section includes two storage tanks having the same structure, the storage tank stores a chemical liquid larger than at least a chemical amount required for one cleaning process in the cleaning chamber. It is desirable to have a storage capacity that can be stored.

A single-wafer substrate cleaning apparatus according to the present invention is a single-wafer substrate cleaning apparatus for performing wet cleaning of wafers one by one in a sealed cleaning housing without using a cassette. A substrate rotating means for supporting and rotating one wafer in a horizontal state, a cleaning chamber for forming a cleaning processing space for a wafer rotatably supported by the substrate rotating means on an outer peripheral portion of the substrate rotating means; Chemical supply means for supplying a cleaning liquid to the front and back surfaces of the wafer rotatably supported by the means, the chemical supply means,
It is characterized by comprising the above-mentioned chemical liquid recycling system.

In a preferred embodiment, the cleaning chamber is vertically movable relative to the substrate rotating means, and the cleaning processing space is provided in an inner peripheral portion of the cleaning chamber. The annular cleaning tank to be formed is concentrically arranged so as to surround the wafer supported by the substrate rotating means, and is arranged in a plurality of stages in the up and down direction. One is
The cleaning chamber is configured to be moved to a position corresponding to the wafer supported by the substrate rotating means and positioned by the vertical movement of the cleaning chamber, and the chemical liquid supply means is connected to the annular cleaning tank, respectively. A plurality of the above-mentioned chemical liquid recycling systems.

In the single-wafer substrate cleaning of the present invention, a cleaning step is performed on the front and back surfaces of the wafer in a sealed cleaning housing with a chemical solution, and the used chemical solution to be recycled is sent to a chemical solution supply / recovery section. While being collected and cleaned, the density is corrected by the density correction unit and reused.

In this case, the chemical supply / recovery section includes a plurality of storage tanks for storing the chemicals, and a chemical circulating section for circulating the chemicals in the storage tanks through the concentration correction section and performing a cleaning process. The plurality of storage tanks can be selectively connected to the chemical liquid circulation unit.

Therefore, while the chemical in one of the storage tanks is supplied to and used in the cleaning chamber to execute the cleaning process, the chemical in the other storage tank is circulated in the chemical circulating section to clean the tank. In addition, the concentration can be corrected and the chemical solution can be efficiently reused without interrupting the cleaning process cycle.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show a single wafer type substrate cleaning apparatus provided with a chemical solution recycling system according to the present invention.

Specifically, the substrate cleaning apparatus is configured to perform wet cleaning of wafers W one by one in a hermetically sealable cleaning housing 1 without using a cassette, and to support and rotate one wafer W in a horizontal state. Substrate rotating device (substrate rotating means) 2, a cleaning chamber 3 capable of relative vertical movement, a chemical liquid supply device (chemical liquid supplying device) 4 for supplying a cleaning liquid, and an inert gas for preventing oxidation. An inert gas supply device (inert gas supply means) 5 and a control device 6 that controls these driving units in conjunction with each other are provided as main components. In addition, the chemical liquid supply device 4 is mainly configured with a chemical liquid recycling system RS, and enables the chemical liquid used in the substrate cleaning device to be reused.

The upper portion of the cleaning housing 1 is a sealable space for the cleaning process, and the lower portion is disposed in the upper space so as to be an installation portion for driving various devices. Although not specifically shown in the upper space of the cleaning housing 1,
An openable and closable substrate loading / unloading port is provided, and the substrate loading / unloading port has a structure in which airtightness and watertightness of this portion are secured when the substrate is loaded and closed.

The substrate rotating device 2 rotates a single wafer W horizontally while supporting the wafer W horizontally during spin cleaning and spin drying. A drive motor 12 that is mounted and supported and that rotates the rotating shaft 10 is provided.

The substrate support portion 11 and the rotating shaft 10 are rotatably arranged in a vertically upright state at the center of the cleaning housing 1 via a bearing support cylinder 13.
One is configured to support one wafer W in a horizontal state.

Specifically, the substrate support 11 is provided with the rotating shaft 1
A plurality of support arms 14, 14,... For mounting and supporting the peripheral portion of the wafer W are provided on a disk 11a fixed horizontally to zero.

These support arms 14, 14,... Are arranged radially in a horizontal state, and the front ends thereof are claw portions 14a for supporting the peripheral portion of the wafer W. The claw portions 14a, 14a of these support arms 14, 14,.
Are set to be at the same height as each other, thereby supporting the peripheral portion of the wafer W in a horizontal state.

Although not specifically shown, the support surface of the claw portion 14a has a cross-sectional shape corresponding to the contour shape of the peripheral portion of the wafer W. The portion is formed so as to abut and support the peripheral edge portion in a point contact state or a line contact state.

The rotating shaft 10 is rotatably supported in an upright manner via a bearing support cylinder 13 and has a lower end connected to a driving motor 12 so as to be able to drive the belt. , And the substrate supporting portion 11 is rotated at a predetermined number of rotations. The rotation speed of the rotating shaft 10 is set to, for example, a low speed of 40 to 50 rpm during the spin cleaning process, and about 3000 rpm during the spin drying.
m. is set to high speed.

The cleaning chamber 3 is a portion for cleaning the wafer W. The inner diameter of the cleaning chamber 3 is set in relation to the substrate supporting portion 11 of the substrate rotating device 2 as described later. Next, a cleaning processing space for the wafer W that is rotatably supported by the substrate rotation device 2 is formed.

Specifically, the cleaning chamber 3 has a plurality of annular processing tanks 15 arranged vertically in the inner peripheral portion thereof.
18 and a structure capable of moving up and down in the vertical direction with respect to the substrate rotating device 2.

In the illustrated embodiment, the annular processing tanks 15 to 18 are concentrically arranged so as to surround the wafer W supported by the substrate supporting portion 11 of the substrate rotating device 2 and are vertically arranged in four stages. They are arranged.

The inner peripheral edge of each of the annular processing tanks 15 to 18 is in non-contact with the outer peripheral edge of the substrate support portion 11 of the substrate rotating device 2, and an annular gap formed between both edges is formed.
The interval is set so as to be small enough to prevent leakage of the cleaning liquid or the like to the lower side.

The cleaning chamber 3 is supported vertically vertically by a lift guide (not shown) so as to be vertically movable, and moves up and down by a predetermined stroke with respect to the substrate support portion 11 of the substrate rotating device 2. A mechanism 20 is provided.

The elevating mechanism 20 includes a feed screw mechanism (not shown) for elevating and lowering the support frame 23 supporting the cleaning chamber 3, and a drive motor 22 for rotating the feed screw mechanism.

Then, in accordance with the cleaning process, the cleaning chamber 3 is driven by the drive motor 22 in conjunction with the operation of the substrate rotating device 2 to be described later via the feed screw mechanism.
Is lifted up and down by a predetermined stroke in the vertical direction, and any one of the annular processing tanks 15 to 18 in which the cleaning process is to be performed is mounted on the wafer W supported by the substrate supporting unit 11 of the substrate rotating device 2. , The position in the height direction is selectively positioned.

In the four annular processing tanks 15 to 18, the openings of the chemical solution recovery passages 15a to 18a openably open and close, respectively. These chemical liquid recovery paths 15a to 18a collect the cleaning liquid in the processing tanks 15 to 18, and are directly connected to the chemical liquid recycling system RS of the chemical liquid supply device 4 or a drain liquid path (not shown) via the chemical liquid recovery path 21. As will be described later, the opening is performed only when the cleaning process is performed, and is closed when the cleaning process is performed in another processing tank.

The chemical liquid supply device 4 supplies a cleaning liquid to the front and back surfaces of the wafer W which is rotatably supported by the substrate rotating device 2. The chemical liquid supply device 4 includes an upper jet nozzle 25 provided at an upper portion in the cleaning housing 1, A lower ejection nozzle portion 26 provided inside the rotating shaft 10 of the substrate rotating device 2, a disposable chemical solution supply system DS for supplying a disposable chemical solution to both the ejection nozzle portions 25, 26, and both ejection nozzle portions 25, 26 Recycling System RS that supplies recycled chemicals to Japan
And

The upper injection nozzle 25 is provided with the substrate rotating device 2.
The cleaning liquid is jetted and supplied from above to the surface of the wafer W supported by the substrate support portion 11, and is provided at the upper portion in the cleaning housing 1. The injection nozzle portion 25 is provided at the upper part in the cleaning housing 1 so as to be horizontally turnable in a downward state, and is drivingly connected to a swing drive motor (not shown).

Then, the spray nozzle portion 25 horizontally or horizontally rotates from the outer periphery to the center with respect to the surface of the wafer W which is rotatably supported by the substrate supporting portion 11 of the substrate rotating device 2 in a horizontal state. Then, after stopping, the cleaning liquid is injected and supplied.

In the illustrated embodiment, the upper spray nozzle section 25 is provided with a number of nozzle ports corresponding to the type of the cleaning liquid to be supplied, and specifically, three nozzle ports are provided ( Not shown). These nozzle ports are respectively connected to an APM liquid supply source (chemical liquid recycling system R) of the chemical liquid supply device 4 through a chemical liquid supply path 27 as shown in FIG.
S), the pure water supply source, the DHF liquid supply source (disposable chemical liquid supply system DS), and the inert expected supply device 5 respectively function as supply ports for the APM liquid, the pure water, and the DHF liquid.

The lower jet nozzle portion 26 is for jetting and supplying a cleaning liquid to the back surface of the wafer W from below, and is provided inside the rotating shaft 10 of the substrate rotating device 2. The lower injection nozzle portion 26 is provided with four nozzle ports, and these nozzle ports are connected through the chemical solution supply path 27,
Are connected to the chemical liquid recycling system RS, RS,... For the APM liquid, the pure water, the DHF liquid, and the inert gas supply device 5, and function as supply ports for the APM liquid, the pure water, the DHF liquid, and N ₂ . .

The chemical liquid recycling system RS has an injection nozzle.
Supply source for supplying cleaning chemicals to the control units 25 and 26
In the illustrated embodiment, the APM (NH_FourOH +
H_TwoO _Two+ H_TwoO) APM liquid for cleaning with liquid
A recycling system RS is provided.

Correspondingly, the processing tanks 15 to 18 in the cleaning chamber 3 are such that the lowermost processing tank 15 is used for the cleaning step using the APM liquid, and the upper processing tank 16 is used for the cleaning step using the DHF liquid. The upper processing tank 17 is for rinsing with pure water, and the uppermost processing tank 18 is for spin drying.

The basic structure of the chemical liquid recycling system RS is the same regardless of which chemical is used. For example, the basic structure of the APM liquid recycling system RS is shown in FIG.
As shown in FIG.

That is, the APM liquid recycling system R
S includes a chemical solution supply / recovery unit 30 that supplies and recovers a chemical solution (APM solution) to and from the cleaning chamber 3 of the single-wafer cleaning apparatus, and a concentration correction unit 31 that corrects the concentration of the chemical solution in the chemical solution supply / recovery unit 30. Provided as the main part.

The chemical supply / recovery section 30 includes a plurality of (two in the illustrated case) storage tanks 35 and 36 for storing the chemicals, and the chemicals in the storage tanks 35 and 36 are supplied to the concentration correction section 31.
And a chemical solution circulating unit 37 for circulating and cleaning the solution.

The two storage tanks 35 and 36 have the same structure, and the storage capacity of each of the storage tanks 35 and 36 is at least one cleaning processing step in the annular processing tanks 15 to 18 of the cleaning chamber 3. It is set so as to be larger than the required amount of the chemical.

The two storage tanks 35, 36 are connected to one of the nozzle openings of the upper and lower injection nozzles 25, 26 in the cleaning housing 1 (in this case, for the APM liquid cleaning step) by the chemical supply path 27. Of the storage tanks 35 and 36, and the chemicals in the storage tanks 35 and 36
The chemical pump 4 is provided by a supply pump 40 provided in
1 to the upper and lower injection nozzles 25 and 26. A line heater 42 is disposed in a covering shape over substantially the entire length of the chemical solution supply path 27, and is configured to heat and raise the temperature of the chemical solution passing through the chemical solution supply path 27 as necessary.

On the other hand, the two storage tanks 35 and 36 are connected to one of the annular processing tanks 15 to 18 (in this case, the lowermost processing tank 15 for the APM liquid cleaning step) by the chemical liquid recovery path 21. The used chemical liquid which is connected and is supplied to the front and back surfaces of the wafer W from the upper and lower injection nozzles 25 and 26 and collected in the annular processing tank 15 is supplied to the chemical liquid filter 43 of the chemical liquid recovery path 21. Via the storage tank 3
Collected at 5,36.

Switching valves 44 and 45, which are air valves, are disposed between the chemical liquid filter 42 and the storage tanks 35 and 36 in the chemical liquid collecting path 21, respectively. The opening is performed only when the cleaning processing is performed in the annular processing tank 15, and is closed when the cleaning processing is performed in the other processing tank, and one of the switching valves 44 or 45 is opened. When in operation, the other switching valve 45 or 44 is closed.

The chemical circulating section 37 is provided with the two storage tanks 3.
There is provided a chemical circulation path 50 that returns to the storage tanks 35 and 36 again from the storage tanks 5 and 36 via the concentration correction unit 31. This chemical liquid circulation path 50 is provided with switching valves 51a, 51b and 52a, which are composed of the storage tanks 35 and 36 and air valves, respectively.
The circulating system 50A and the circulating system 50B are selectively formed by switching control of these control valves.

That is, one set of switching valves 51a, 51
b is opened and the other set of switching valves 52a, 52
By closing b, a circulation system 50A is formed that returns from the storage tank 35 to the storage tank 35 again via the concentration correction unit 31. On the other hand, on the other hand, when the other set of switching valves 52a and 52b is opened and the one set of switching valves 51a and 51b is closed, the storage tank 36 is stored again via the density correction unit 31. Tank 36
A circulation system 50B that returns to is formed.

In the chemical circulation path 50, a circulation pump 55 for circulating the chemical, a chemical filter 57 for filtering impurity particles in the chemical, and a temperature controller 56 for adjusting the temperature of the chemical are arranged. . Each of these devices has a conventionally known general structure, and the chemical liquid filter 57 has the same structure as the chemical liquid filters 41 and 43 described above.

The concentration correcting section 31 is provided with a concentration sensor 60 for measuring the concentration of the chemical circulating in the circulation path 50 of the chemical circulating section 37.
A correction value calculating unit 61 for comparing the measured value of the density sensor 60 with a preset set value to calculate a correction value necessary for the density correction; and a circulation path according to the correction value of the correction value calculating unit 61. A correction chemical supply unit 62 for supplying a correction chemical to the 50 chemicals is provided.

The correction chemical supply section 62 is provided with ammonia (NH ₄ O) for correcting the concentration of the chemical (APM liquid in this case).
H), aqueous hydrogen peroxide (H ₂ O ₂ ) and pure water (DIW)
For each of the supply sources 65a to 65c,
To 66c, and correction amount control units 68a to 68c including switching valves 67a to 67c formed of air valves.

The chemical (A) flowing through the chemical circulation path 50
The concentration of the PM solution is measured by the concentration sensor 60 of the concentration correction unit 31, and the measured value is used as the correction value calculation unit 61.
Is compared with a set value set in advance by NH ₄ O
The correction amount of each of H, H ₂ O _{2 and} DIW is calculated, and according to the calculation result, the correction chemical liquid supply unit 62 (68
a to 68c) require the amount of each chemical solution from NH ₄ OH, H ₂ O ₂ or DIW supply sources 65a to 65c (correction amount).
Is supplied to the chemical liquid flowing through the chemical liquid circulation path 50 to correct the concentration.

More specifically, each of the correction amount control sections 68a-68
c, the switching valves 67a to 67c of the chemical liquids that need to be corrected
Is opened, and the chemical solution is supplied from the supply sources 65a to 65c to the circulation path 5.
0, and when the measured flow rates (supply amounts) of the integrated flow meters 66a to 66c reach the above-mentioned correction values, the switching valves 67a to 67c are closed. This correction operation is continued until the concentration (measured value) measured by the concentration sensor 60 reaches the concentration (set value) set in advance by the correction value calculation unit 61. As a result, the concentration of the chemical flowing through the chemical liquid circulation path 50 is increased. Is finally corrected to the set value.

In the APM liquid recycling system RS configured as described above, the switching valves 44, 45, and 5
By switching control of 1a, 51b and 52a, 52b,
While one of the two storage tanks 35, 36, for example, the chemical in the storage tank 35 is being supplied to the cleaning chamber 3, the chemical in the other storage tank 36 circulates through the vapor chemical circulation path 50. Then, the temperature is adjusted while the impurity particles in the chemical solution are filtered and cleaned, and the concentration is corrected by the concentration correction unit 31.

Although the disposable chemical liquid supply system DS is not specifically shown, in this embodiment, the pure water and the DHF liquid are used without being recycled.

The inert gas supply device 5 supplies an inert gas for preventing oxidation to the surface of the wafer W rotatably supported by the substrate rotating device 2. The inert gas supply device 5 is provided at the upper portion of the cleaning housing 1. An ejection section 70 is provided. In the illustrated embodiment, N ₂ gas (nitrogen) is used as the inert gas.

The gas ejection portion 70 is, specifically, a circular lid member that forms a closed space for drying around the surface of the wafer W that is rotatably supported by the substrate rotation device 2 in cooperation with the cleaning chamber 3. It is a form.

The outer diameter edge of the gas ejection portion 70 is designed to be closely engaged with the inner diameter edge of the cleaning chamber 3, that is, the outer diameter edge of the uppermost annular processing tank 18, whereby A required minimum hermetically sealed drying space is formed around the surface of the wafer W rotatably supported by the substrate rotating device 2.

The control device 6 controls each of the components of the above-described substrate cleaning apparatus in a mutually interlocking manner, and the control device 6 automatically executes a series of wet processing steps.

That is, in the substrate cleaning apparatus configured as described above, the wafer W supported by the substrate support 11 of the substrate rotating device 2 and the processing tank of the cleaning chamber 3 are moved up and down in the cleaning chamber 3. Positioning with any of 15 to 18 is selectively performed, and the wafer W supported by the substrate support unit 11 is horizontally rotated at a predetermined rotation speed by the substrate rotation device 2.

By selecting and setting the recipe for the cleaning step, i) APM + DHF + (O ₃ + DI
W) + DRY, ii) APM + DHF + DRY, iii) AP
M + DRY and iv) cleaning steps such as DHF + DRY can be selectively performed.

For example, the washing step (A) of the above ii)
In the case of (PM + DHF + DRY), the wafer W on the substrate supporting unit 11 is first positioned and arranged in the lowermost processing tank 15 by the vertical positioning of the cleaning chamber 3, and the APM liquid is supplied from the injection nozzle units 25 and 26. Along with
Spin cleaning is performed by low-speed rotation by the substrate rotating device 2.

Subsequently, the substrate is positioned and arranged in the second processing tank 17 from the top, and pure water is supplied from the injection nozzles 25 and 26, and rinsing is performed by the substrate rotating device 2 rotating at a low speed.

Further, the DHF solution is supplied from the injection nozzles 25 and 26 while being positioned and disposed in the third processing tank 16 from the top, and spin cleaning is performed by the substrate rotating device 2 rotating at a low speed.

The substrate is again positioned and disposed in the processing tank 17, and pure water is supplied from the injection nozzles 25 and 26, and rinsing is performed by low-speed rotation of the substrate rotating device 2.

Finally, spin drying is performed by high-speed rotation of the substrate rotating device 2 while the N ₂ gas is being injected from the injection nozzle portion 26 while being positioned and arranged in the uppermost processing tank 18.

In the single wafer type substrate cleaning apparatus according to the present invention, the cleaning process for the front and back surfaces of the wafer W is performed in the sealed cleaning housing 1 using the chemical solution. APM liquid in the embodiment) is a chemical liquid supply / recovery section 3 of the chemical liquid supply device 4.
0 and cleaned, and the density correction unit 31
Is used for density correction and reused.

In this case, the chemical supply / recovery section 30 cleans by circulating the two storage tanks 35 and 36 for storing the chemical and the chemicals in the storage tanks 35 and 36 via the concentration correcting section 31. And a chemical liquid circulation section 37 for processing,
The two storage tanks 35 and 36 can be selectively connected to the chemical solution circulating unit 37.

Accordingly, while the chemical solution in one storage tank 35 or 36 is supplied to and used in the cleaning chamber 3 to execute the cleaning process, the chemical solution in the other storage tank 36 or 35 is circulated in the chemical solution circulating unit 37. Then, the cleaning can be performed and the concentration can be corrected, and the chemical solution can be efficiently reused without interrupting the cleaning process cycle.

The above-described embodiment merely shows a preferred embodiment of the present invention, and the present invention is not limited to this, and various design changes can be made within the scope.

For example, in the illustrated embodiment, two storage tanks 35 and 36 can be selectively connected to the chemical solution circulating section 37, and any one of the two storage tanks 35 and 36 can be connected. While the chemical is supplied to the cleaning chamber 3, the chemical in the remaining storage tank 36 or 35 is circulated in the chemical circulating unit 37 to be cleaned and concentration corrected. However, the number of storage tanks is not limited to that shown in the figure, and may be appropriately increased according to the purpose.

In this case, while one of the chemicals in the plurality of storage tanks is being supplied to the cleaning chamber 3, the chemicals in the other storage tanks are circulated in the chemical circulating unit 37 to be cleaned. And the density is corrected.

The chemical used in this embodiment is as follows:
This is merely an example. For example, HPM (HCl + H ₂
O ₂ + H ₂ O) or SPM (H ₂ SO ₄ + H ₂ O ₂ + H ₂₎
Other cleaning liquids such as O) can be used depending on the purpose.

Further, the substrate cleaning apparatus according to the present embodiment can be used alone as well as a basic unit configuration of a substrate cleaning system provided with various devices such as a loading unit, an unloading unit, and a transfer robot. Use as an element is also possible.

[0075]

As described in detail above, according to the present invention,
A chemical solution supply / recovery unit for supplying / collecting a cleaning solution to / from the cleaning chamber of the single-wafer cleaning apparatus; and a concentration correction unit for correcting the concentration of the chemical solution in the solution supply / recovery unit. A plurality of storage tanks for storing a chemical solution, and a chemical solution circulating unit for circulating the chemical solution in these storage tanks through the concentration correction unit to perform a cleaning process, and the plurality of storage tanks are selected as the chemical solution circulating unit. In this case, it is possible to provide a chemical recycling technique that can realize efficient reuse of a chemical in relation to a cleaning process cycle in single wafer wet cleaning.

That is, in the single-wafer substrate cleaning of the present invention, a step of cleaning the front and back surfaces of the wafer with a chemical solution is performed in a closed cleaning housing.
The used chemical liquid to be recycled is collected by the chemical liquid supply / collection unit and cleaned, and the concentration is corrected by the concentration correction unit and reused.

In this case, the chemical supply / recovery section includes a plurality of storage tanks for storing the chemicals, and a chemical circulation section for circulating the chemicals in these storage tanks through the concentration correction section for cleaning. While the chemical solution in one of the storage tanks is supplied to the cleaning chamber and used to perform the cleaning process, the chemical solution in the other storage tanks is circulated in the chemical circulating unit to be cleaned. The concentration can be corrected at the same time, whereby the chemical solution can be efficiently reused without interrupting the cleaning process cycle.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing the internal configuration of a single wafer type substrate cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a chemical liquid recycling system of the single-wafer substrate cleaning apparatus.

[Explanation of symbols]

SR chemical liquid recycling system W wafer 1 cleaning housing 2 substrate rotating device (substrate rotating means) 3 cleaning chamber 4 chemical liquid supplying device (chemical liquid supplying device) 5 inert gas supplying device (inactive gas supplying device) 6 control unit 10 rotating shaft 11 Substrate support part 15-18 Annular processing tank 21 Chemical recovery path 25 Upper injection nozzle part 26 Lower injection nozzle part 27 Chemical liquid supply path 30 Chemical liquid supply and recovery part 31 Concentration correction part 35, 36 Storage tank 37 Chemical liquid circulation part 40 Supply pump 41, 43 Chemical liquid filter 44, 45 Switching valve 50 Chemical liquid circulation path 50A, 50B Circulating system 51a, 51b Switching valve 52a, 52b Switching valve 55 Circulating pump 56 Chemical liquid filter 57 Temperature controller 60 Concentration sensor 61 Correction value calculation unit 62 Correcting chemical liquid Supply unit 70 Gas ejection unit

Claims (9)

[Claims] 1. A chemical liquid recycling system for collecting and reusing a used chemical liquid in a single-wafer substrate cleaning apparatus for performing wet cleaning processing of substrates one by one with a chemical liquid, wherein the cleaning of the single-wafer cleaning apparatus is performed. A chemical solution supply / collection unit that supplies / collects a cleaning chemical solution to / from the chamber; and a concentration correction unit that corrects the concentration of the chemical solution in the chemical solution supply / collection unit. A storage tank, and a chemical circulating unit that circulates the chemicals in these storage tanks through the concentration correction unit to perform a cleaning process, wherein the plurality of storage tanks can be selectively connected to the chemical circulating unit. A chemical liquid recycling system for a single wafer type substrate cleaning apparatus. 2. While any of the chemicals in the plurality of storage tanks is being supplied to the cleaning chamber, the chemicals in the other remaining storage tanks are circulated in the chemical circulating unit,
2. The chemical liquid recycling system for a single-wafer substrate cleaning apparatus according to claim 1, wherein the chemical liquid is cleaned and the concentration is corrected. 3. The chemical supply / recovery section includes two storage tanks having the same structure, and the storage tank stores a chemical that is at least larger than a chemical required for one cleaning process in the cleaning chamber. 2. A storage capacity according to claim 1.
Or a chemical liquid recycling system for a single-wafer substrate cleaning apparatus according to item 2. 4. The chemical liquid circulating section of the chemical liquid supply / recovery section includes a chemical liquid circulating path that returns from the two storage tanks to the plurality of storage tanks again via the concentration correction section, and the chemical liquid circulating path includes: The two storage tanks can be selectively communicated with each other by a switching valve. By controlling the switching valve, the other one of the two storage tanks is supplied to the cleaning chamber while the other chemical is being used. The chemical liquid recycling system for a single-wafer substrate cleaning apparatus according to claim 3, wherein the chemical liquid in the storage tank is circulated through the chemical liquid circulation path. 5. A circulating pump for circulating a chemical, a chemical filter for filtering impurity particles in the chemical, and a temperature controller for adjusting the temperature of the chemical are arranged in the chemical circulating path of the chemical circulating section. The chemical liquid recycling system for a single wafer type substrate cleaning apparatus according to claim 4, characterized in that: 6. The concentration correction section, comprising: a concentration sensor for measuring the concentration of the chemical in the liquid circulation section; and a measurement value of the concentration sensor being compared with a preset set value to perform a correction required for the concentration correction. 2. The apparatus according to claim 1, further comprising: a correction value calculating unit that calculates a value; and a correction chemical supply and recovery unit that supplies a correction chemical to the chemical in the chemical circulation unit according to the correction value of the correction value calculation unit. 5. The chemical liquid recycling system for a single-wafer substrate cleaning apparatus according to any one of 5. 7. In a sealed cleaning housing,
What is claimed is: 1. A single-wafer substrate cleaning apparatus for performing wet cleaning of substrates one by one without using a cassette, wherein: a substrate rotating unit configured to support and rotate one substrate in a horizontal state in the cleaning housing; and an outer peripheral portion of the substrate rotating unit. A cleaning chamber that forms a space for cleaning processing of a substrate that is rotatably supported by the substrate rotating unit, and a chemical solution supply unit that supplies a cleaning liquid to the front and back surfaces of the substrate that is rotatably supported by the substrate rotating unit, A single-wafer-type substrate cleaning apparatus, wherein the chemical liquid supply unit includes the chemical liquid recycling system according to any one of claims 1 to 6. 8. The annular cleaning device, wherein the cleaning chamber is vertically movable relative to the substrate rotating means, and the cleaning processing space is formed in an inner peripheral portion of the cleaning chamber. The tanks are concentrically arranged so as to surround the substrate supported by the substrate rotating means, and are arranged in a plurality of stages in the vertical direction. Depending on a cleaning treatment step, one of these annular cleaning tanks is 8. The single wafer according to claim 7, wherein the cleaning chamber is configured to move to a position corresponding to a substrate supported by the substrate rotating means and to be positioned by a vertically moving operation of the cleaning chamber. Type substrate cleaning equipment. 9. The single wafer type substrate cleaning apparatus according to claim 8, wherein the chemical liquid supply means includes a plurality of the chemical liquid recycling systems connected to the annular cleaning tank.