JPH0781926A - Silicon dioxide coating film producing device - Google Patents

Abstract

PURPOSE:To reduce the dust adhering to a substrate and to easily obtain a high quality silicon dioxide coating film by providing a means for ercovering a processing soln. contg. silicon dioxide, etc., in a processing soln. regulating tank, a means for cleaning a treating tank, etc., on a specified device. CONSTITUTION:A substrate 3 to be treated is set in a treating tank 1, and the tank is filled with a processing soln. 2 including a hydrosilicofluoric acid soln. supersaturated with silicon dioxide. An activator 7 for maintaining the supersaturation of the soln. 2 is arranged in a processing soln. regulating tank 4. Further, a means for recovering the soln. 2 in the tank 1 by allowing the soln. to overflow and circulating the soln. through a pump 5 and a line 12, A means for circulating the soln. between a cleaning soln. storage tank 15 and the tank 1 through a cleaning soln. feed line 14 or for injecting the cleaning soln. into the tank 1 to clean it, a means for circulating the processing soln. recovered in the tank 4 through a circulating line 11 and a means for recovering the cleaning soln. to be circulated to the tank 1 in the tank 15 through a recovery line 13 or for discharging the soln. without recovering it are provided to constitute the silicon dioxide coating film producing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon dioxide coating manufacturing apparatus, and more particularly, to a silicon wafer on a substrate to be processed such as a semiconductor wafer or a glass substrate in a semiconductor manufacturing process or a manufacturing process of electronic parts such as a liquid crystal display device. The present invention relates to an apparatus for producing a silicon dioxide film that produces a film from a liquid phase.

[0002]

2. Description of the Related Art A liquid phase film forming method (LP
Since the method D) can form a film at a temperature near room temperature and has a good followability even on a submicron level surface irregularity, a film with a uniform thickness and few defects can be obtained. There is. The liquid phase film forming method of this silicon dioxide film is
For example, JP-A-60-33233 and JP-A-62-2
It is proposed by Japanese Patent Publication No. 0876.

FIG. 8 is an explanatory diagram showing a device configuration of a device for producing a silicon dioxide film by a liquid phase film forming method. The processing tank 1 is loaded with a semiconductor substrate or a glass substrate which is the substrate 3 to be processed, and is immersed in a processing liquid 2 containing a hydrosilicofluoric acid solution in a supersaturated state of silicon dioxide. , A silicon dioxide film is deposited. In the treatment liquid adjusting tank 4, in order to maintain the supersaturated state of the silicon dioxide of the treatment liquid 2, the active material 7 such as aluminum or boric acid is dissolved.

When a substrate to be processed, for example, a semiconductor wafer is immersed in a processing solution containing silicon dioxide in a supersaturated state and a silicon dioxide film is formed on the surface thereof, particles of silicon dioxide or the like that precipitate in the processing solution grow. Coarsely coarsens and floats as so-called dust in the treatment liquid. Further, particles such as silicon dioxide are deposited in the treatment liquid during film formation and adhere to the inner wall of the treatment tank, the inner wall of the pipe passage, the inner wall of the treatment liquid adjusting tank, and the like. As the film formation progresses, particles are further deposited on the particles attached to the wall surface, and the film of the particle layer attached to the wall surface gradually becomes thicker. When the particle layer adhering to the inner wall of the tank or the inner wall of the pipe is peeled off, it also becomes dust floating in the processing liquid. This dust often adheres to the surface of the wafer and reduces the yield of semiconductor devices.

Therefore, in order to remove dust such as silicon dioxide particles in the treatment liquid 2, a circulation means 5 and a filtration means 6 are provided to circulate and filter the treatment liquid. As a circulation means, a pump is used which has no pulsation, does not adversely affect filtration, and has a relatively large circulation flow rate. A filter having a pore size of about 0.05 to 1 μm is used as the filtering means. In addition, a filter is built in a cleaning device and automatically cleaned when the filter becomes clogged.

[0006]

However, in the apparatus configuration of the apparatus for producing a silicon dioxide film as shown in FIG.
The film forming rate is slow, for example, 10 to 20 angstrom /
It takes a very long time to form a film at a film forming rate of min. When the film forming speed is low as described above, the inner wall of the tank or the inner wall of the conduit is considerably contaminated by the adhered particle layer of silicon dioxide and the like when the film forming process is performed once. When the second and third film formations are performed in such a state, the amount of so-called dust in the processing liquid increases, which causes defects in the silicon dioxide film formed on the substrate to be processed. Become.

Conventionally, the film forming process is continued a certain number of times, and after a certain amount of a particle layer of silicon dioxide or the like on the wall surface of the process tank adheres (contaminates), the whole processing solution is discharged and the processing tank is discharged. The processing solution adjusting tank and the circulation pipes were washed.
Therefore, as the number of times of film formation increases, the amount of dust in the processing liquid due to the separation of the silicon dioxide particle layer from the inner wall of the processing tank increases, and the adhesion of dust to the substrate to be processed becomes a problem.
In order to avoid this problem, if the processing tank is cleaned after each film formation, the expensive processing liquid must be completely discharged and discarded after each cleaning, and for the next film formation, In order to reach the required degree of supersaturation of the processing liquid, there arises a problem that it takes time to dissolve the active material. Further, if only the treatment liquid is extracted and stored in another tank or the like, the supersaturation degree of the treatment liquid is lowered, the film forming speed is lowered, and the treatment liquid cannot be reused immediately. In addition, a space for another tank is newly required inside the device, and the device becomes large.

The present invention has been made in view of the problems of the prior art, and it is possible to clean the processing tank after each film formation, and a processing solution necessary for film formation during cleaning of the processing tank. It is an object of the present invention to provide a silicon dioxide film manufacturing apparatus capable of restarting the film forming process immediately after the completion of cleaning without deteriorating the state of supersaturation and the like.

[0009]

SUMMARY OF THE INVENTION An apparatus for producing a silicon dioxide film according to the present invention comprises a treatment liquid containing a hydrosilicofluoric acid solution in which silicon dioxide is supersaturated, and the treatment liquid being brought into contact with a substrate to be treated. Processing tank for depositing a silicon dioxide film on the surface of the substrate, a processing solution adjusting tank for dissolving an active material to maintain a supersaturated state of the silicon dioxide of the processing solution, the processing solution, and the processing tank In a device for producing a silicon dioxide film, which comprises a circulation means for circulating the solution in the solution adjusting tank and a filtering means arranged in a circulation path for the solution, the processing solution in the processing tank is recovered in the processing solution adjusting tank. Means, means for circulating the cleaning liquid between the cleaning liquid storage tank and the processing tank or for injecting the cleaning liquid into the processing tank to clean the processing tank, and circulating the processing liquid recovered in the processing liquid adjusting tank for supersaturation, etc. Hand to maintain the state of When, characterized in that a means for discharging the washing liquid circulating in the treatment tank without recovery after the recovery is or washing the cleaning liquid reservoir.

[0010]

[Operation] The processing liquid in the processing tank is collected in the processing liquid adjusting tank,
The cleaning liquid stored in the cleaning liquid storage tank can be circulated, held, or passed through the empty processing tank to clean the processing tank. Since the processing liquid collected in the processing liquid adjusting tank during the cleaning of the processing tank is provided in the processing liquid adjusting tank, a supersaturated state of the processing liquid can be maintained as it is. Further, since a means for collecting or retaining the cleaning liquid circulating in the processing tank in the cleaning liquid storage tank and discharging the passed cleaning liquid is provided, the cleaning liquid is collected after the completion of cleaning, washed with water, and then the processing liquid is again prepared in the processing liquid adjusting tank. It is possible to circulate the product from the above into the processing tank and shift to the next film formation.

In this way, the processing bath is cleaned every time a film is formed, and during the cleaning, the processing liquid is stored while maintaining a supersaturated state. Therefore, the next film formation can be performed immediately after cleaning the processing tank without discarding the expensive processing liquid.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described with reference to FIGS.
Will be described with reference to.

In the present embodiment, in addition to the main circulation path 8 for film formation, the treatment liquid circulation line 11 and the treatment liquid recovery line 1
2, a cleaning liquid recovery line 13, a cleaning liquid supply line 14, and the like, and various processing liquids and cleaning liquid circulation connection paths.

FIG. 1 shows the flow of the treatment liquid in the main circulation casing 8 by white arrows. In the main circulation box 8 for forming a film, the treatment liquid is increased in supersaturation by dissolving the active material 7 in the treatment liquid adjusting tank 4, and the treatment liquid is circulated by the pump P ₁ and the two filters F ₁ , F ₂ through one of the _two , and enters into the processing tank 1 to deposit a silicon dioxide film on the substrate 3 to be processed. The processing liquid pumped by the pump P ₁ overflows the processing tank 1 and flows into the processing liquid adjusting tank 4. The processing liquid adjusting tank 4 of this embodiment has a capacity Q larger than that of the conventional processing liquid adjusting tank 4 so that the processing liquid in the processing tank can be collected.

FIG. 2 shows the flow of the processing liquid in the processing liquid recovery line 12 by white arrows. After completion of one film forming process, the substrate 3 to be processed is pulled out from the processing bath 1 and the processing bath 1 is washed. Prior to cleaning the treatment tank 1, the treatment liquid in the treatment tank 1 is collected in the treatment liquid adjusting tank 4. The recovery of the processing liquid is circulated along the processing liquid recovery line 12 by the pump P _{3 as} shown by the white arrow, the valve V ₂ is opened, and the processing liquid in the processing tank 1 is sent to the processing liquid adjusting tank 4. After the film forming process, the pump P ₁ that circulates the processing liquid in the processing liquid adjusting tank 4 is stopped, and the entire amount of the processing liquid in the processing tank 1 is collected in the processing liquid adjusting tank 4.

FIG. 3 shows the flow of the processing liquid in the processing liquid adjusting tank circulation line 11 with white arrows. Treatment liquid is treatment liquid adjustment tank 4
After being collected, the processing liquid of the processing liquid adjusting tank 4 by the pump P ₁ is passed through the filter F ₁ from the valve V _5, it is returned from the valve V ₆ to the processing liquid adjusting tank 4. By this treatment liquid circulation line 11, the active material 7 is dissolved in the treatment liquid adjusting tank 4, and the supersaturation degree of the treatment liquid is maintained. Also, the temperature controller 9
As a result, the liquid temperature of the processing liquid is maintained at about 20 to 50 ° C. which is a suitable temperature for film formation. Further, the treatment liquid is filtered by the filter F ₁ in the same manner as in the case of normal film formation, particles of silicon dioxide and dust in the treatment liquid are removed, and the treatment liquid is in a state ready for film formation similar to that during film formation. Maintained at.

FIG. 4 shows the cleaning liquid circulation line 14.
The black arrow in the figure indicates the flow of the cleaning solution. Hydrofluoric acid (HF) is used as the cleaning liquid, and the hydrofluoric acid dissolves silicon dioxide particles and removes a particle layer (dirt) adhering to the inner wall of the processing tank, the inner wall of the pipeline, and the like. The cleaning liquid is stored in the storage tank 15, and the cleaning of the processing tank 1 after the processing liquid in the processing tank 1 is collected in the processing liquid adjusting tank 4 and emptied is performed by circulating, holding, or passing the cleaning liquid. As indicated by the black arrow in the figure, the cleaning liquid is circulated from the storage tank 15 by the pump P ₂ , passes through the valve V ₇ , the filter F ₂ , and the valve V _8, and then passes through the processing tank 1.
to go into. The cleaning liquid dissolves the particles of silicon dioxide on the inner wall of the processing tank and the inner wall of the pipe, removes the dirt on the particle layer, and the valve V
_It is returned to the cleaning liquid storage tank 15 through _one valve V ₉ .

FIG. 5 shows the flow of the cleaning liquid in the cleaning liquid recovery line 13 by a black arrow. When the cleaning of the processing tank 1 is completed,
The pump P ₂ is stopped and the circulation of the cleaning liquid is stopped. Then, the valves V ₃ and V ₉ are opened, and the cleaning liquid in the processing tank 1 spontaneously drops and is collected in the cleaning liquid storage tank 15.

FIG. 6 shows by arrows the flow of washing with pure water after the washing of the treatment tank with the washing liquid is completed. The pure water flows through the valve 10 from the pure water supply port 18, passes through the valve V ₇ , the filter F ₂ , and the valve V ₈ , and the processing tank 1
Flows in. Then, the valve V ₁ is opened and the valve V _{1
Since 3} , V ₉ are closed, the pure water used to wash the processing tank 1 overflows and drains from the valve V ₁ to the drain 17. By washing with pure water, the hydrofluoric acid (HF) remaining in the processing tank 1 and the pipeline is dissolved in water and removed.

FIG. 7 shows with arrows the flow of draining pure water from the treatment tank after the washing with water. The valves V ₁ and V ₃ are opened,
The pure water in the processing tank 1 will fall to the drain 17 by spontaneous fall. All the cleaning steps are completed by cleaning with pure water, the valves V ₁ and V ₃ are closed, the direction of the three-way valve V ₆ is converted from the processing liquid adjusting tank circulation line 11, and returned to the main circulation casing 8. The processing liquid circulating in the processing liquid adjusting tank 4 is
It is sent to the processing tank 1 and circulates in the main circulation path 8. By loading the substrate 3 to be processed in the processing tank 1, the next film can be formed in the processing tank 1 cleaned by cleaning.

[0021]

As described above, according to the apparatus for producing a silicon dioxide film of the present invention, cleaning can be performed every time the film formation is completed, and dust adhered to the substrate to be processed in the processing tank can be removed. The amount can be reduced and a high-quality silicon dioxide film can be formed. Further, since the processing liquid can be immediately maintained in a state capable of forming a film during the cleaning of the processing tank, it is possible to continuously perform the film forming process without wasting time until the next film formation. . In addition, since it is possible to maintain the supersaturation degree during storage of the treatment liquid, maintain the temperature, or maintain the amount of dust generated in the treatment liquid by using the existing treatment liquid adjusting tank, circulation means, and filtration means, comparison The present invention can be implemented only by adding a simple circulation path.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a device configuration of a silicon dioxide film manufacturing apparatus according to an embodiment of the present invention, in which a white arrow indicates a main circulation path for forming a film on a substrate to be processed.

FIG. 2 is an explanatory diagram showing a device configuration of a silicon dioxide film manufacturing apparatus according to an embodiment of the present invention, in which a white arrow indicates a recovery line of a processing liquid to a processing liquid adjusting tank.

FIG. 3 is an explanatory diagram showing a device configuration of a silicon dioxide film manufacturing apparatus according to an embodiment of the present invention, in which a white arrow indicates a processing solution adjusting tank circulation line of a processing solution.

FIG. 4 is an explanatory diagram showing a device configuration of a device for manufacturing a silicon dioxide film according to an embodiment of the present invention, in which a black arrow indicates a circulation line of a cleaning liquid.

FIG. 5 is an explanatory diagram showing a device configuration of a device for manufacturing a silicon dioxide film according to an embodiment of the present invention, in which a black arrow indicates a cleaning liquid recovery line.

FIG. 6 is an explanatory diagram showing a device configuration of a silicon dioxide film manufacturing apparatus of an embodiment of the present invention, in which an arrow indicates a pure water washing line.

FIG. 7 is an explanatory diagram showing a device configuration of a silicon dioxide coating manufacturing device according to an embodiment of the present invention, and an arrow in the drawing indicates drainage of pure water.

FIG. 8 is an explanatory view showing a device configuration of a conventional device for manufacturing a silicon dioxide film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 treatment tank 2 treatment liquid 3 substrate to be treated 4 treatment liquid adjusting tank 8 main circulation path 11 treatment liquid circulation line 12 treatment liquid recovery line 13 cleaning liquid recovery line 14 cleaning liquid supply line

Claims (1)

[Claims] 1. A treatment liquid containing a hydrosilicofluoric acid solution in which silicon dioxide is supersaturated, and a treatment tank for bringing the treatment liquid into contact with a substrate to be treated to deposit a silicon dioxide film on the surface of the substrate. A treatment liquid adjusting tank for dissolving an active material in order to maintain a supersaturated state of silicon dioxide in the treatment liquid, a circulation means for circulating the treatment liquid between the treatment tank and the treatment liquid adjusting tank, and circulation of the treatment liquid A device for producing a silicon dioxide film, comprising: a filtering means arranged in a path; a means for collecting the treatment liquid in the treatment tank into the treatment liquid adjusting tank; and a cleaning liquid circulating between the washing liquid storage tank and the treatment tank. Or a means for injecting a cleaning liquid into the processing tank to clean the processing tank, a means for circulating the processing liquid recovered in the processing liquid adjusting tank to maintain a state, and a cleaning liquid circulating in the processing tank for storing the cleaning liquid. Collect in the tank There is apparatus for manufacturing a silicon dioxide coating, characterized in that a means for discharging without recovery after washing.