JP2001015468A - Processing method of substrate and chemical processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method of substrate and a chemical processing system in which production cost can be reduced by reusing chemical used for processing the substrate. SOLUTION: The chemical processing system processes a wafer 25 with chemical in a processing bath 10. The chemical processing system comprises the processing bath 10 for receiving pure water 13 in the upper phase and chemical 11 in the lower phase while separating from each other, an apparatus 17 for purifying the chemical and pure water used for processing the wafer 25 in the processing bath 10, and piping 18, 19 for returning the purified chemical and pure water back to the processing bath 10. According to the arrangement, chemical used for processing the substrate can be recycled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of processing a substrate to be processed and a chemical processing apparatus, and more particularly to a method of processing a substrate to be processed and a chemical processing apparatus which can reduce manufacturing costs.

[0002]

2. Description of the Related Art An example of a conventional method for treating a substrate (wafer) with a chemical solution will be described below.

An Al film is deposited on a wafer, and a resist film is provided on the Al film. Next, the Al film is etched on the wafer by etching the Al film using the resist film as a mask. Then, in order to prevent the side wall of the Al wiring from being etched in the lateral direction in a subsequent step, a polymer as a side wall protective film is formed on the side wall of the Al wiring.

[0004] Since this side wall protective film is finally unnecessary, it is removed using a chemical solution (for example, dichloromethane). FIG. 3 shows a chemical treatment apparatus used at this time. FIG. 3 is a configuration diagram schematically showing a conventional chemical treatment apparatus.

[0005] The chemical processing apparatus shown in FIG.
, Washing tank 113, rinsing tank 114, dryer 115
And This chemical liquid tank 111 contains dichloromethane. Pure water is filled in the washing tank 113, and the wafer as a substrate to be processed is washed with the pure water overflowing in the washing tank 113. Further, the chemical processing apparatus has an ultrasonic vibration device (not shown) for applying ultrasonic vibration to the chemical in the chemical tank 111.

Next, a method for processing a wafer with a chemical using the above-described chemical processing apparatus will be described.

First, the wafer is put into a chemical solution tank 111,
While applying ultrasonic vibration to the polymer on the wafer by the ultrasonic vibration device, the polymer is removed with dichloromethane. At this time, the reason why the ultrasonic vibration is applied is to enhance the effect of removing the polymer.

After that, the wafer is taken out of the chemical bath 111 and put in the washing bath 113. Then, pure water overflows in the washing tank 113 and water replacement is performed to remove chemical components on the wafer surface.

Next, the wafer is taken out of the washing tank 113 and put into the rinsing tank 114, and the wafer is rinsed in the rinsing tank 114. Thereafter, the wafer is taken out of the rinsing tank 114 and put into a dryer 115, and the
At 15 the wafer is dried.

[0010]

In the above-mentioned conventional method for processing a substrate to be processed, after a chemical solution treatment is performed, pure water overflows in a state where the wafer is placed in the washing tank 113, so that the chemical solution on the wafer surface is removed. A large amount of pure water was required to remove the components, thereby increasing the production cost.

Further, the used chemical solution in the chemical solution tank 111 is discarded after being neutralized, agglomerated and precipitated, and cannot be recycled. This is an obstacle to reducing the manufacturing cost.

Further, in the above-mentioned conventional chemical processing apparatus, since the chemical tank 111 and the washing tank 113 are separately provided, the number of processing tanks is increased, the apparatus is enlarged, and as a result, the manufacturing cost is increased. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of processing a substrate to be processed and a chemical liquid processing apparatus capable of reducing manufacturing costs by reducing the number of processing tanks. It is in. It is another object of the present invention to provide a method of processing a substrate to be processed and a chemical processing apparatus which can reduce the manufacturing cost by recycling the chemical after treating the substrate with the chemical.

[0014]

In order to solve the above-mentioned problems, a method for processing a substrate to be processed according to the present invention is directed to a chemical processing tank in which upper-phase pure water and lower-phase chemical are put in a state separated from each other. A method for treating a substrate to be treated with a chemical using a chemical liquid treatment tank, wherein the step of putting the substrate to be treated into a chemical solution in a lower phase in the chemical treatment tank comprises: And pulling up from the chemical solution into the pure water of the upper phase.

In the above method for treating a substrate to be processed, pure water and a chemical solution are put into a chemical solution treatment tank, and pure water is arranged above the liquid phase interface by utilizing the difference in specific gravity between the two, and is placed below the liquid phase interface. After the chemical solution is arranged in the phase and the substrate to be processed is put in the lower phase chemical solution in the processing tank, the substrate to be processed is pulled up from the lower phase chemical solution to the upper phase pure water in the chemical solution processing tank. Thus, foreign substances or by-products attached to the substrate to be processed are removed by utilizing the surface tension at the liquid phase interface. Therefore, the number of treatment tanks for the chemical solution can be reduced. As a result, the device can be made compact and the manufacturing cost can be reduced.

Further, the method for processing a substrate to be processed according to the present invention further includes a step of taking out the substrate to be processed outside the chemical solution processing tank after the step of lifting, and purifying a chemical and pure water thereafter. Is preferred. This makes it possible to recycle the chemical after the substrate to be processed is subjected to the chemical treatment, thereby reducing the manufacturing cost.

In the method for processing a substrate to be processed according to the present invention, when the chemical solution and pure water are purified, the mixed solution of the chemical solution and pure water is heated and boiled, and the boiling point of the chemical solution and pure water is increased. A method of separating and purifying both depending on the difference may be used.

The chemical processing apparatus according to the present invention is a chemical processing apparatus for processing a substrate to be processed with a chemical processing tank using a chemical processing tank, in which pure water is supplied to an upper phase and chemical liquid is supplied to a lower phase in a separated state. And a means for placing the substrate to be processed into the chemical processing tank.

Further, in the chemical processing apparatus according to the present invention, the means includes, after putting the substrate to be processed into the lower phase chemical in the chemical processing tank, removing the substrate from the lower phase chemical. It is preferable that the upper phase be moved so as to be pulled up into pure water.

The chemical processing apparatus according to the present invention is a chemical processing apparatus for performing chemical processing on a substrate to be processed using a chemical processing tank. The chemical processing apparatus is configured to separate pure water into an upper phase and a chemical liquid into a lower phase. A chemical processing tank, a purifier for purifying the chemical and pure water after the chemical processing of the substrate to be processed in the chemical processing tank, and the chemical and pure water purified by the purifier again into the chemical processing tank. And a return pipe.

In the above chemical processing apparatus, the substrate to be processed is subjected to chemical processing in the chemical processing tank, the chemical and pure water are purified by a purifier, and then the chemical and pure water are piped from the purifier to the chemical processing tank. You can put it back again. For this reason, the chemical solution can be reused. Therefore, manufacturing costs can be reduced.

Further, in the chemical treatment apparatus according to the present invention, the purifier heats and boiles the mixed solution of the chemical solution and the pure water after the chemical treatment, and combines the two with the difference between the boiling points of the chemical solution and the pure water. They may be separated and purified.

Further, in the chemical processing apparatus according to the present invention, a cooling device for cooling the chemical and the pure water is attached to the pipe, and the chemical and the pure water cooled by the cooling device are respectively provided. It is preferable that a filter for removing foreign substances contained therein is attached.

In the chemical processing apparatus according to the present invention, the chemical may include CHCl ₂ .

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a chemical processing apparatus according to an embodiment of the present invention. 2A to 2C are configuration diagrams for explaining a method of processing a substrate to be processed with a chemical using the chemical processing apparatus illustrated in FIG. 1.

As shown in FIG. 1, the chemical processing apparatus includes a processing tank 10 for performing chemical processing on a substrate to be processed such as a wafer, a purifier 17 for purifying the processed chemical, cooling devices 21 and 22, and It is composed of filters 23, 24 and the like.

The treatment tank 10 contains a chemical solution 11 such as CHCl ₂ (dichloromethane) and pure water 13. In the treatment tank 10, the chemical solution 11 and the pure water 13 are separated from each other. The chemical solution 11 is arranged below the liquid phase interface 12, and the pure water 13 is arranged above the liquid phase interface 12. Separation in this way consists of chemical solution 11 and pure water 13
This is because there is a difference in specific gravity.

The processing tank 10 and the purifier 17 are connected by a pipe 16. The pipe 16 is used to convert the chemical solution 11 and the pure water 13 after the wafer is subjected to the chemical processing in the processing tank 10 into the purifier 1.
It is for pouring into 7.

The purifier 17 is provided with a heater 15 as a heating means. The purifier 17 heats and boiles a mixture of the chemical solution 11 and pure water 13 to be purified by the heater 15, thereby separating and purifying the two using the difference in boiling points between the chemical solution 11 and pure water 13. is there.

The purifier 17 and the processing tank 10 are connected to pipes 18, 1
9 are connected. The pipe 18 is for returning the chemical solution 11 purified by the purifier 17 to the processing tank 10 again. The pipe 19 is for returning the purified water 13 purified by the purifier 17 to the processing tank 10 again.

In each of the pipes 18 and 19, cooling devices 21 and 22 are arranged, and
3, 24 are arranged. The cooling devices 21 and 22 cool the chemical solution and the pure water purified by the purifier 17, respectively. The filters 23 and 24 are provided with the cooling device 2
This removes foreign substances contained in the chemical solution and the pure water cooled by the cooling liquids 1 and 22, respectively.

Next, a method of processing a substrate to be processed will be described.

First, as shown in FIG.
A plurality of wafers 25 housed in a basket (not shown) are immersed in a lower phase chemical solution (dichloromethane) 11 using a driving means (not shown).

Next, after a lapse of a predetermined time, as shown in FIG. 2B, the immersed wafer 25 is gradually pulled up from the lower phase chemical solution 11 into the upper phase pure water 13. At this time, as the wafer 25 passes through the liquid phase interface 12, foreign substances and by-products (for example, polymer residues) attached to the surface of the wafer 25 due to surface tension at the liquid phase interface 12 are removed and collected.

Thereafter, as shown in FIG. 2C, when the whole wafer 25 is completely pulled up into the pure water 13 of the upper phase, foreign substances and by-products on the surface of the wafer 25 are removed.
Is almost completely removed from Then, the chemical liquid 11 attached to the surface of the wafer 25 in the pure water 13 is removed.

Next, the wafer 25 is taken out of the processing tank 10 by the driving means. By performing such a chemical treatment on the wafer 25 a plurality of times, many foreign substances and by-products are left in the chemical solution 11, and then the chemical solution 11 and the pure water 13 are purified through the pipe 16 shown in FIG. Vessel 1
7 is introduced.

Thereafter, in the purifier 17, the introduced chemical solution and pure water are heated and boiled by the heater 15, and the chemical solution and pure water are separated and purified by utilizing the difference in boiling point. Thereby, foreign substances, by-products, and the like in the chemical solution and pure water are removed.

Next, the purified chemical solution is returned to the processing tank 10 again through the pipe 18. At this time, the boiling chemical solution is cooled and liquefied by the cooling device 21, and thereafter, foreign substances and the like remaining in the chemical solution are removed by the filter 23. Further, the purified pure water is returned to the processing tank 10 again through the pipe 19. At this time, the boiling pure water is cooled and liquefied by the cooling device 22, and then the filter 24
As a result, foreign substances and the like remaining in the pure water are removed.

The chemical solution and pure water thus purified by the purifier 17 are returned to the treatment tank 10 for recycling.

According to the above embodiment, the pure water 13 and the chemical solution 11 are put into the treatment tank 10, and the pure water 13 is disposed above the liquid phase interface 12 by utilizing the difference in specific gravity between the two. Interface 12
After the chemical solution 11 is arranged in the lower phase and the wafer 25 is put in the lower chemical solution 11 in the processing tank 10, the wafer 25 is transferred from the lower chemical solution 11 into the upper phase pure water in the processing tank 10. Pull up. As a result, foreign substances and by-products (such as polymers) attached to the wafer 25 are removed using the surface tension of the liquid phase interface 12. Therefore, there is no need to separately provide a chemical solution tank and a washing tank as in the conventional chemical solution treatment apparatus, and it is possible to remove foreign substances and by-products and to perform washing with one treatment tank 10. The number can be reduced. As a result, the device can be made compact and the manufacturing cost can be reduced.

Further, as described above, foreign substances and by-products (polymers and the like) attached to the wafer 25 are removed by utilizing the surface tension of the liquid phase interface 12, so that a conventional chemical liquid processing apparatus is used. No ultrasonic vibration device is required. Therefore, also in this respect, the manufacturing cost can be reduced.

Further, in the present embodiment, since it is not necessary to overflow pure water as in the conventional chemical liquid treatment apparatus, the amount of pure water used can be reduced, thereby reducing the manufacturing cost.

Further, in the present embodiment, as described above, the treated chemical solution 11 and pure water 13 can be reused after being purified by the purifier 17. Therefore, the manufacturing cost can be significantly reduced as compared with the conventional method for processing a substrate to be processed.

The present invention is not limited to the above embodiment, but can be implemented with various modifications. For example,
In the above embodiment, the polymer adhering to the wafer 25 is removed by using dichloromethane as the chemical solution 11, but the present invention is not limited to this chemical solution, and the substrate to be processed is processed by using another chemical solution. Alternatively, it is also possible to carry out a washing treatment.

[0046]

As described above, according to the present invention, a substrate to be processed is subjected to chemical treatment using a chemical treatment tank in which pure water of the upper phase and chemical solution of the lower phase are separately stored. Therefore, it is an object of the present invention to provide a processing method of a substrate to be processed and a chemical processing apparatus which can reduce the manufacturing cost by reducing the number of processing tanks.

According to the present invention, after the substrate to be processed is subjected to the chemical treatment in the chemical treatment tank, the chemical and the pure water are purified by the purifier, and then the chemical and the pure water are transferred from the purifier to the chemical treatment tank. Return by pipe. Therefore, it is possible to provide a processing method for a substrate to be processed and a chemical processing apparatus which can reduce the manufacturing cost by recycling the chemical after the substrate is processed with the chemical.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a chemical solution processing apparatus according to an embodiment of the present invention.

FIGS. 2A to 2C are configuration diagrams for explaining a method of processing a substrate to be processed with a chemical using the chemical processing apparatus shown in FIG. 1;

FIG. 3 is a configuration diagram schematically showing a conventional chemical treatment apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Treatment tank 11 Chemical liquid 12 Liquid phase interface 13 Pure water 15 Heater 16 Pipe 17 Purifier 18, 19 Pipe 21, 22 Cooling device 23, 24 Filter 25 Wafer 111 Chemical tank 113 Rinse tank 114 Rinse tank 115 Dryer

Claims (9)

[Claims] 1. A processing method for processing a substrate to be processed using a chemical processing tank containing pure water of an upper phase and a chemical liquid of a lower phase separated from each other, wherein the lower phase in the chemical processing tank is provided. And a step of pulling up the substrate to be processed from the lower phase chemical solution into the upper phase pure water in the chemical solution treatment tank. Processing method of the substrate to be processed. 2. The substrate to be processed according to claim 1, further comprising a step of taking out the substrate to be processed outside the chemical processing tank after the step of pulling up, and thereafter purifying a chemical and pure water. Processing method. 3. When purifying the chemical and pure water, a mixture of the chemical and pure water is heated and boiled, and the two are separated and purified according to the difference in boiling point between the chemical and pure water. The method for processing a substrate to be processed according to claim 2. 4. A chemical processing apparatus for performing chemical processing on a substrate to be processed by using a chemical processing tank, wherein a chemical processing tank for introducing pure water into an upper phase and a chemical solution into a lower phase in a state separated from each other, Means for placing the substrate to be processed into a chemical processing tank. 5. The method according to claim 1, wherein after the substrate to be processed is put into the lower-phase chemical in the chemical processing tank, the substrate is pulled up from the lower-phase chemical into the upper-phase pure water. 5. The chemical processing apparatus according to claim 4, wherein the chemical liquid processing apparatus is moved in such a manner. 6. A chemical processing apparatus for performing chemical processing on a substrate to be processed using a chemical processing tank, wherein the chemical processing tank is configured to receive pure water in an upper phase and a chemical solution in a lower phase while being separated from each other. A purifier for purifying the chemical solution and pure water after the substrate to be processed is subjected to the chemical treatment in the chemical treatment tank; and a pipe for returning the chemical solution and the pure water purified by the purifier to the chemical treatment tank again. A chemical treatment apparatus characterized by the above-mentioned. 7. The purifier heats a mixed solution of the chemical solution and the pure water after the chemical treatment and brings the mixture to a boil, and separates and purifies the mixture according to a difference in boiling point between the chemical solution and the pure water. The chemical treatment device according to claim 6. 8. A filter for cooling a chemical solution and pure water, respectively, attached to the pipe, and a filter for removing foreign substances contained in each of the chemical solution and pure water cooled by the cooling device. The chemical liquid treatment apparatus according to claim 7, wherein a chemical liquid treatment device is attached. 9. The chemical processing apparatus according to claim 4, wherein the chemical contains CHCl ₂ .