JP2000183024A - Substrate-processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing apparatus, wherein a process bath and piping of a single-vessel substrate processing device used in a cleaning process for a semiconductor and liquid-crystal substrate are cleaned sufficiently with less amount of pure water. SOLUTION: An overflow type process bath 1 comprising an inner bath 3, where a substrate 11 is submerged for processing of a substrate surface and an outer bath 2 for recovering a liquid overflowed from the inner bath 3, a processor liquid recovering pipe 13 for recovering a processor liquid into a recovery tank 12, where a processor liquid 20 is temporarily stored from the inner bath 3, a processor liquid supply pipe 21 which supplies the processor liquid 20 to the inner bath 3 from the recovery tank 12, a circulating piping 8 which sends the processor liquid 20 into the inner bath 3 from the outer vessel 2, and a drain piping 15 provided to each of the inner vessel 3 and outer vessel 2, are provided. Here, a pure water supply pipe 16 is connected, to each of the processor liquid supply pipe 21, processor liquid recovery pipe 13, circulating piping 8, and the drain piping 15 through valves 41-46.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a substrate processing apparatus. More specifically, the present invention relates to a substrate processing apparatus for cleaning a substrate such as a semiconductor wafer using a chemical solution.

[0002]

2. Description of the Related Art One of the indispensable processes for manufacturing semiconductors and liquid crystal substrates is a cleaning process. The cleaning step is performed for the purpose of removing minute dust (hereinafter, referred to as particles) on the substrate surface, peeling off the resist, and etching, and selecting and using a chemical solution corresponding to each.

FIG. 4 shows a flowchart of a cleaning step in a semiconductor device manufacturing process. As shown in the drawing, in the cleaning step, for example, when two types of chemicals used for the processing are used (A) and (B), the substrate is first treated with the chemical (A) (step S1), and then the substrate is washed with water. (Step S
2) Further, the substrate is treated with the chemical solution (B) (Step S)
3) The substrate is washed again with water (step S4). Then, final washing is performed (step S5), and drying is performed (step S6).

Conventionally, in such a washing process, a multi-tank type washing apparatus in which a plurality of chemical solution tanks and a washing tank suitable for each processing are prepared for each step, and the processing is sequentially performed in each tank. Was mainstream.

FIG. 5 is a schematic view of a conventional multi-tank type cleaning apparatus for performing the cleaning step shown in FIG. As shown in the figure, this multi-tank type cleaning apparatus includes a chemical (A) processing tank 81, a water cleaning tank 82, a chemical liquid (B) processing tank 83, and a water cleaning tank 84 for performing the processing of steps S1 to S6 in FIG. , A final washing tank 85 and a drying treatment tank 86, and these chemical tanks and washing tanks are arranged in order.
For example, 25 substrates to be processed are vertically accommodated in a carrier 71 as one lot, and a plurality of substrates 61 accommodated in the carrier 71 are immersed in respective tanks by a conveyance means such as a robot, and are sequentially processed. Is done. Such a multi-tank type cleaning apparatus is excellent in productivity because a plurality of substrates to be processed in the carrier 71 can be simultaneously processed in each of the tanks.

FIG. 6 is a detailed configuration diagram of the chemical (A) processing tank 81 or the chemical (B) processing tank 83 of the conventional multi-tank processing apparatus shown in FIG. Chemical processing tank 8 for processing substrates
1 (83) comprises an outer tank 52 and an inner tank 53. Substrate 61
In order to adjust the chemical solution 50 for processing, a plurality of chemical solutions are stored in the respective weighing tanks 54, the amounts thereof are adjusted by a liquid level meter 55, and supplied to the outer tank 52 via the chemical solution supply pipe 56. The concentration of the chemical is adjusted by pure water supplied from a pure water supply pipe 57. The chemical solution thus supplied is sent from the outer tank 52 to the inner tank 53 via the circulation pipe 58. The circulation pipe 58 is provided with a pump 59, whereby the chemical in the outer tank 52 passes through the filter 60 to remove impurities such as particles in the chemical and is sent to the inner tank 53.

If the substrate 61 to be processed is usually a semiconductor substrate of 8 inches or less, it is put into the inner tank 53 in a state of being accommodated in a carrier in units of about 25 or 50 as described above. . Chemical 50 in chemical treatment tank 81
Processes the substrate 61 while circulating and filtering. This chemical 50
The valve 63 is opened as necessary, and the inner tank 5 of the processing tank 81 is opened.
The exhaust gas is discharged through a drain pipe 62 provided in the fuel cell 3. The substrate 61 after the treatment with the chemical solution 50 is taken out of the chemical solution treatment tank 81 (83) by the robot as described above, and transported to another dedicated washing tank 82 (84) provided adjacently. The substrate is washed in a dedicated washing tank 82 (84). Therefore, the inner tank 53 of the chemical treatment tank 81 (83) is not provided with a pure water supply pipe for washing.

However, in the above-described conventional multi-tank type washing apparatus, since a plurality of tanks are arranged in a straight line, the equipment is very long and occupies a large area. In particular, the size of liquid crystal substrates has been increasing with the recent increase in size of display devices. There is no standard for liquid crystal substrate size like semiconductors, but currently 600mm × 720mm or 650mm
A × 830 mm substrate has been introduced into the manufacturing process, and it is expected that the size will increase in the future. Accordingly, the size of the substrate processing apparatus is accordingly increased, and more space is required. Furthermore, in the production of semiconductors and liquid crystals, very high air cleanliness is required during production.As the size of the equipment increases, the area of a clean room and the like for air purification also increases, resulting in additional costs. It takes. Therefore, it is required to reduce the number of processing tanks and downsize the apparatus.

FIG. 7 shows an apparatus configuration for miniaturizing such a substrate processing apparatus. (A) shows the same treatment tank 87 for the chemical (A) treatment (step S1) and water washing (step S2) shown in FIG.
Similarly, by performing the chemical (B) treatment (step S3) and the water washing (step S4) in the same processing tank 88, the number of processing tanks is reduced from six to four in FIG. It is trying to make it. (B) further reduces the size of the apparatus by performing the processing from the chemical solution (A) processing (step S1) to the chemical solution (B) processing water washing and final water washing (step S5) in one processing tank 91. (C) further downsizes the apparatus by performing the processing up to the final drying processing (step S6) in the single processing tank 93.

FIG. 8 is an explanatory view of an underwater replacement system for performing a chemical treatment and a water washing treatment in the same treatment tank in order to reduce the size of the apparatus. In this underwater replacement method, of the inner tank 53 and the outer tank 52 forming the processing tank 51, the inner tank 53
Then, the substrate 61 is treated with a chemical solution, and then pure water is supplied from the bottom portion of the inner bath from a pure water supply pipe 64 connected to the bottom of the inner bath 53, and the chemical solution overflows from the inner bath 53 and is gradually replaced with pure water. Then, finally, the substrate is washed by making all the pure water. The chemical liquid overflowing to the outer tank 52 is discharged from the drain pipe 62. By using such an underwater replacement method, the chemical solution treatment and the water washing treatment can be performed continuously in one treatment tank.

[0011]

However, in the conventional single-tank substrate processing apparatus using the underwater replacement method, the chemical solution and pure water are discarded for each processing, so that not only the running cost is increased but also the cost is increased. In addition, a large amount of water or a chemical solution such as neutralization is required for the treatment, and the burden on the environment is increased.

On the other hand, Japanese Patent Application Laid-Open No. 7-99177 discloses a single-tank substrate processing apparatus. The substrate immersion processing apparatus described in this publication is intended to reduce the running cost by suppressing the consumption of the processing liquid of the immersion processing apparatus while preventing the substrate processing apparatus for performing surface treatment of a semiconductor substrate or the like from becoming large. The drainage path derived from the overflow type substrate processing tank is branched, and one is connected to the drain via the drainage valve, and the other is connected to the processing liquid storage vessel via the processing liquid recovery valve as the processing liquid recovery path. I do. Then, for each of a plurality of types of surface treatments, the processing liquid overflowing from the substrate processing tank is collected in a storage container via a processing liquid recovery valve, and circulated again to the substrate processing tank for reuse.

However, in the substrate processing apparatus described in this publication, a pure water pipe is connected only to the supply side pipe of the processing liquid supply side piping system composed of a plurality of pipes and the recovery side or drainage side piping system. And perform a water washing process.
The pure water pipe is not connected to the drain system or the collection system. Therefore, during the water washing process, there is a possibility that the chemical solution remains in the drain side or the collection side piping, and especially when the chemical solution remains in the collection side piping system, it may mix with another chemical solution to be used next and cause a problem. is there.

Further, when the valves of the respective piping systems are closed and pure water is supplied from the pure water pipe to replace the chemicals in the processing tank, the piping between each valve and the processing tank is in a dead-end state and the replacement is performed. If it does not proceed, the washing process takes a long time. For this reason, the productivity decreases, the amount of expensive pure water used increases, and the cost increases.

The present invention has been made in consideration of the above-mentioned conventional technology, and can sufficiently clean a processing tank or a pipe of a single-tank substrate processing apparatus used in a cleaning process of a semiconductor or a liquid crystal substrate. It is an object of the present invention to provide a substrate processing apparatus which can be efficiently performed in a short time to reduce the amount of pure water used.

[0016]

In order to achieve the above object, according to the present invention, there is provided an overflow type comprising an inner tank for immersing a substrate to treat the surface of the substrate and an outer tank for collecting a liquid overflowing from the inner tank. A processing tank, a processing liquid recovery pipe for recovering the processing liquid from the inner tank to a recovery tank for temporarily storing the processing liquid, a processing liquid supply pipe for supplying the processing liquid from the recovery tank to the inner tank, In a substrate processing apparatus having a circulation pipe for sending a processing liquid from an outer tank to an inner tank, and a drain pipe provided in each of the inner tank and the outer tank, the processing liquid supply pipe, the processing liquid recovery pipe, the circulation pipe, and the drain Provided is a substrate processing apparatus, wherein a pure water supply pipe is connected to a pipe via a valve.

According to this configuration, since pure water is supplied to all the pipes connected to the substrate processing apparatus, the entire apparatus including all the pipes can be efficiently cleaned in a short time. In addition, the inside of the recovery tank can be washed, and there is no danger of mixing chemicals, and the amount of pure water used can be reduced.

In a preferred embodiment, the recovery tank is provided with a temperature adjusting unit.

According to this configuration, by adjusting the temperature of the chemical in the recovery tank, the temperature of the chemical in the tank can be kept equal to the processing temperature in the processing tank, and the substrate processing time can be reduced. it can.

In a preferred configuration example, there is provided a concentration adjusting means for measuring a chemical solution concentration or a mixing ratio in the processing tank, supplying a chemical solution based on the measurement result, and maintaining the processing solution concentration. .

According to this configuration, even if the concentration of the chemical solution changes due to mixing with the residual pure water for washing or other causes, the concentration can be appropriately measured and the chemical solution can be always kept at a constant concentration.
The reliability of substrate processing is improved.

In a preferred embodiment, the recovery tank has a pure water supply pipe and a drain pipe.

According to this configuration, since pure water can be directly supplied to the recovery tank for storing the chemical liquid and the cleaning liquid can be directly washed, the tank can be washed and replaced with the new liquid when replacing the old recovered chemical liquid with a new chemical liquid. Mixing with a liquid can be avoided, and highly reliable chemical liquid processing can be performed.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a substrate processing apparatus according to an embodiment of the present invention. A processing tank 1 for processing a substrate includes an outer tank 2 and an inner tank 3. The outer tank 2 is provided with a circulation pipe 8 that sends the chemical solution in the outer tank 2 to the inner tank 3. From the circulation pipe 8, an outer tank processing liquid recovery pipe 14 that sends the chemical in the outer tank 2 to a recovery tank 12 for temporarily storing the chemical via a valve 33 is provided in a branched manner. The inner tank 3 includes an inner tank processing liquid collection pipe 13 for sending the chemical solution in the inner tank 3 to the collection tank 12 via the valve 34, and a collection tank 12.
There is provided a processing liquid supply pipe 21 to which a chemical is supplied through a valve 35, a pump 18, a filter 19, and a valve 36. Further, a drain pipe 15 for discharging the processing liquid is provided in each of the outer tank 2, the inner tank 3, and the recovery tank 12.

The pure water pipe 16 is connected to the outer pipe connection side of the circulation pipe 8 via a valve 46. The circulation pipe 8 is provided with a valve 31, a pump 9 and a filter 10, and is connected to the bottom of the inner tank 3 via a valve 34.

The four pipes connected to the bottom of the inner tank 3 and the two pipes connected to the bottom of the outer tank 2 are all connected via valves 41 to 46 as shown in FIG. The water supply pipe 16 is connected. A drain pipe 15 is connected to the recovery tank 12 together with a pure water supply pipe 16.
Each drain pipe 1 of the inner tank 3, the outer tank 2, and the collection tank 12
5 are provided with valves 37, 38, and 39, respectively.

The flow of substrate processing by such a configuration is as follows.
Chemical liquid recovery, water washing with pure water supply, pure water discharge, and chemical liquid supply from a recovery tank are performed. In this case, the substrate may be moved after the completion of the water washing to prepare for the next substrate processing, or when another chemical processing is performed, a chemical supply pipe or another chemical processing pipe is used after pure water discharge as described later. The chemical is supplied from the recovery tank and the chemical processing is repeated. Hereinafter, an example of such a flow will be described in more detail.

In order to adjust the processing liquid (chemical liquid in this case) 20 for processing the substrate 11, a plurality of chemical liquids are stored in the respective weighing tanks 4, the amounts of which are adjusted by the liquid level gauge 5, and the chemical liquid supply pipes 6. Is supplied to the outer tank 2 via The concentration adjustment of the treatment liquid is performed by pure water supplied from a pure water supply pipe 7. The processing liquid supplied in this manner is sent from the outer tank 2 to the inner tank 3 via the circulation pipe 8. At this time, the valves 31 and 32 are opened, and the other valves are closed (see Table 1 described later).

A pump 9 is provided in the circulation pipe 8, and the chemical in the outer tank 2 is removed by the pump 9 to remove particles in the chemical through the filter 10 and sent to the inner tank 3. In this way, the processing liquid can be circulated. Further, the circulation pipe may be provided with a temperature control unit such as a damper or a heater for reducing pulsation in the pipe, if necessary.

After the substrate has been immersed for a predetermined period of time, the processing liquid is recovered in the recovery tank 12 for reuse. At this time, the valves 31, 32, 33, and 34 are opened, and the other valves are closed. The pump 9 is operated. Thereby, the processing liquid in the inner tank passes through the inner tank processing liquid recovery pipe 13 and the valve 34 and is stored in the recovery tank 12, and the processing liquid in the outer tank flows through the pump 9 to the outer tank processing liquid recovery pipe 14 and the valve 33. As a result, all the processing liquid is collected in the collection tank 12.

When the processing liquid recovery operation is completed, pure water is supplied into the processing tank to wash the inside of the apparatus. At this time, the valves 41, 42, 43, 44, 45, and 46 are opened to supply pure water to the treatment tank. Thereby, the inside of a processing tank and each piping are filled with pure water. During this cleaning process, the drainage is
8 is opened and discharged from a drain pipe 15 provided in the outer tank. Also, the pump 9 is stopped. As a result, the chemical solution left or entered in the pipe is discharged. By connecting the pure water supply pipe 16 to all the pipes connected to the processing tank 1 in this manner, the processing liquid in the pipe can be quickly cleaned, and the time for cleaning the pipe can be shortened. The amount is also reduced.

Further, at the time of washing with water, the valve 47 is opened, and pure water is spouted from the shower 17 onto the inner wall of the outer tub 2 to remove the processing liquid adhering to the inner wall. At this time, in order to avoid reattachment to the substrate 11 due to the rebound of the shower 17, the water level is higher than the upper end of the substrate in the inner tank 3. By performing the pure water supply and the shower for a certain period of time, the water washing of the substrate 11 and the processing tank 1 is completed. After completion, the substrate 11
Is transported to the next manufacturing step by a transport means (not shown). Thereafter, the valves 37 and 38 are opened to discharge all the pure water in the inner tank 3 and the outer tank 2 from the drain pipe 15.

When processing the same substrate once again with different chemicals, prepare a plurality of circulation pipes and a collection tank,
Processing can also be performed. In this case, the process is performed in such a manner that the processing liquid is sequentially flown from each recovery tank to the processing tank. In such a case, there is a concern that a product produced by mixing with the processing liquid used previously becomes particles, but in the processing apparatus of the present invention, the processing tank and the pipe are completely washed with water as described above,
No problem.

When all the pure water in the processing tank 1 has been discharged,
The pump 18 is operated by opening the valves 35 and 36. The chemical in the recovery tank 12 passes through the processing liquid supply pipe 21, and after the particles are removed by the filter 19, is reused in the processing tank 1. Therefore, the amount of the processing liquid used can be reduced.

The chemical in such a recovery tank is repeatedly reused and then appropriately replaced with a new liquid. In this case, the old liquid is discharged by opening the valve 39. This collection tank 1
2 is provided with a pure water supply pipe 16. After draining the old liquid, the valve 48 is opened to supply pure water, and the pure water is discharged and supplied again. This sequence is repeated several times. Thereby, the inside of the collection tank 12 can be washed. As a result, mixing of the new solution and the old solution can be avoided, and the new solution can be used with higher purity.

Table 1 shows a series of valve opening / closing operations and pump operations during the substrate processing described above. In Table 1, "-" means that the valve is closed and the pump is stopped.

[0037]

[Table 1]

FIG. 2 is a block diagram showing a substrate processing apparatus according to the present invention provided with a temperature adjusting unit. Temperature adjustment may be required depending on the processing liquid used for substrate processing.
At this time, a circulation pipe 22 for the recovery tank 12 is provided,
By operating the pump 23, the processing liquid passes through the filter 24, and the temperature is adjusted by a temperature adjustment unit 25 including a heater or an electronic cooling / heating unit on the circulation pipe. By performing the temperature adjustment in the collection tank 12 in this manner, the temperature of the chemical solution in the tank can be maintained at a temperature required for substrate processing, and the time until the next substrate processing is shortened.

When the old liquid and the new liquid in the recovery tank 12 are exchanged, the recovery tank 12 can be cleaned while stirring using the circulation pipe 22, so that the cleaning time is shortened. Other configurations such as piping and the operation and effect are the same as those in the example of FIG. 1 described above.

FIG. 3 is a block diagram of a substrate processing apparatus according to the present invention, provided with a density adjusting means. When the chemical solution to be reused is supplied to the processing tank 1, pure water adhering to the inner wall of the processing tank, pure water existing in the processing liquid supply pipe 21, valves 31, 32, 34, 37, 38 There is a possibility of mixing with pure water or the like existing between the processing tanks 1. There is no problem as long as the change in the mixing ratio of the processing solution due to the mixing with the pure water is negligibly small, but the concentration of the processing solution may significantly change.

In the present embodiment, in order to cope with this point, a concentration measuring device (or a mixing ratio measuring device) 26 is provided on the circulation pipe 8 so as to be diluted with pure water and a chemical solution that is insufficient or a chemical solution having a changed mixing ratio. Is appropriately weighed and supplied to the processing tank 1. In this case, it is also possible to perform feedback control such that a valve or the like of the chemical solution weighing system 100 is automatically adjusted according to a measured value such as a concentration. As a result, the processing solution can always be used under appropriate chemical solution concentration conditions, and the reliability of the processing is improved.

[0042]

As described above, according to the present invention, the space of a clean room or the like can be saved by reducing the size of the apparatus, and the chemical solution itself can be saved and the chemical solution for waste liquid treatment can be saved by reusing the chemical solution. In addition, since pure water supply pipes are connected to all of the pipes connected to the processing tank of the substrate processing apparatus, the cleaning efficiency is increased, the amount of pure water used is reduced,
Cost can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram including a temperature adjustment unit in the substrate processing apparatus according to the present invention.

FIG. 3 is a configuration diagram of a substrate processing apparatus according to the present invention including a density adjusting unit.

FIG. 4 is a flowchart of a cleaning step in a semiconductor device manufacturing process.

FIG. 5 is a schematic view of a conventional multi-tank cleaning apparatus.

FIG. 6 is a detailed configuration diagram of a chemical treatment tank of a conventional multi-tank treatment apparatus.

FIG. 7 is an apparatus configuration diagram for reducing the size of the substrate processing apparatus.

FIG. 8 is an explanatory diagram of an underwater replacement system.

[Explanation of symbols]

1: processing tank, 2: outer tank, 3: inner tank, 4: weighing tank,
5: Level gauge, 6: Chemical supply pipe, 7: Pure water supply pipe, 8 circulation pipe, 9: Pump, 10: Filter, 11: Substrate, 1
2 recovery tank, 13: inner tank processing liquid recovery pipe, 14: outer tank processing liquid recovery pipe, 15: drain pipe, 16: pure water supply pipe, 1
7: shower, 18: pump, 19: filter, 2
0: treatment liquid, 21: treatment liquid supply pipe, 22: circulation pipe, 2
3: pump, 24: filter, 25: temperature adjustment unit, 26: concentration meter, 100: chemical solution weighing system.

Claims (4)

[Claims] 1. An overflow type processing tank comprising an inner tank for immersing a substrate to treat the surface of the substrate, an outer tank for collecting a liquid overflowing from the inner tank, and a processing liquid temporarily stored in the inner tank. A treatment liquid collection pipe for collecting the treatment liquid in a collection tank for storing the treatment liquid, a treatment liquid supply pipe for supplying the treatment liquid from the collection tank to the inner tank, a circulation pipe for sending the treatment liquid from the outer tank to the inner tank, In a substrate processing apparatus having a drain pipe provided in each of an inner tank and an outer tank, a pure water supply pipe is connected to each of the processing liquid supply pipe, the processing liquid recovery pipe, the circulation pipe, and the drain pipe via a valve. A substrate processing apparatus characterized by the above-mentioned. 2. The substrate processing apparatus according to claim 1, wherein the collection tank includes a temperature adjustment unit. 3. The apparatus according to claim 1, further comprising a concentration adjusting means for measuring a concentration or a mixing ratio of the chemical in the processing tank, supplying a chemical based on the measurement result, and maintaining the concentration of the processing liquid. The substrate processing apparatus according to any one of the preceding claims. 4. The substrate processing apparatus according to claim 1, wherein the recovery tank has a pure water supply pipe and a drain pipe.