JPH0719552A - Clean chemical processing equipment - Google Patents

Abstract

(57) [Summary] [Purpose] Achieve the safety and hygiene of chemical vapor and mist and the cleanliness of the upper surface of the chemical treatment tank with minimal local exhaust. [Structure] Clean air supply means 1 for forming a clean air flow from an upper part of a clean chamber 10 toward an upper part of a chemical liquid processing tank 12.
1 and an exhaust means 14 for locally exhausting the air around the upper part of the chemical liquid processing tank 12 to the outside of the clean chamber 10, the outer peripheral wall of the overflow tank 13 being lower than the upper surface of the chemical liquid processing tank 12, and the overflow tank 13 The exhaust port 14 for local exhaust by the exhaust means 14 at a position higher than the level of the recovered chemical liquid of
It is characterized in that a is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clean chemical liquid processing apparatus for carrying out chemical liquid processing in the manufacturing process of thin film devices such as semiconductors, and more particularly to air blowing and exhaust to minimize the scattering of chemical liquid vapor and mist. The present invention relates to a clean chemical liquid processing apparatus that ensures the cleanliness of the upper part of the chemical liquid processing tank while performing the chemical liquid processing while preventing it by exhausting.

[0002]

2. Description of the Related Art Generally, in chemical treatment equipment, in order to prevent vapors and mists of harmful chemicals such as hydrogen fluoride and fuming nitric acid from splashing around and damaging workers, flammable chemicals such as acetone. A local exhaust system is installed in order to prevent the vapor of the steam from scattering and causing a fire.

FIG. 5 and FIG. 6 show a conventional chemical liquid processing device having such a basic structure.

In this device, a chemical treatment tank 51 is provided on the bottom of the clean chamber 50, and a local exhaust means 54 having an exhaust port 52 is provided on the upper part of the clean chamber 50.

As shown in FIG. 6, the chemical vapor 61 or mist is locally generated only on the upper surface of the chemical treatment tank 51. However, the exhaust operation of the local exhaust means 54 causes the external clean air in the clean chamber 50. An air flow 62 that is sucked and rises in the clean chamber 50 is formed, and the clean chamber 5 is carried away while carrying away steam and mist generated on the upper surface of the chemical liquid processing tank 51.
It is discharged from the upper part of 0 to the outside.

Therefore, it is possible to prevent the vapor and mist generated on the upper surface of the chemical treatment tank 51 from scattering around.

However, the clean air flow 62 forms a vortex flow 62a along the inner surface of the peripheral wall of the clean chamber 50, which falls on the bottom of the clean chamber 50 and accumulates dust 63.
May be partly wound up and scattered in the clean air flow 62 to reach the upper surface of the chemical treatment tank 51.

However, since no consideration has been given to the influence of the air flow around the chemical liquid processing tank 51, the cleanliness of the upper portion of the chemical liquid processing tank 51 is worse than the clean outside air introduced. In many cases, it adversely affects the processing of chemicals.

In addition, in this type of chemical liquid processing device, not only suction is performed around the location where the chemical liquid is present, but also the entire circumference is exhausted. For this reason, the amount of exhaust gas per unit time increases, which leads to an increase in the capacity of exhaust equipment, and when using a dangerous chemical liquid, the exhaust gas cannot be directly discharged to the atmosphere, so it is necessary to detoxify it. The large amount of exhaust increases the cost and imposes a heavy burden.

Japanese Unexamined Patent Publication (Kokai) No. 63-248449 discloses a chemical solution treating apparatus which solves this problem.

As shown in FIG. 7, a clean air supply device 65 including a filter and a fan is provided above the clean chamber 62 to form a clean air flow 67 toward the upper part of the chemical treatment tank 51. At the same time, a clean air flow is blown from one side of the clean chamber 51 by another clean air supply means 68 including a filter and a fan, and is exhausted from the other side, so that the position immediately above the upper surface of the chemical treatment tank 51 is achieved. An air curtain 71 is formed so as to traverse it.

In such a structure, the clean air 50 flowing downward and the air curtain 71 satisfy the cleanliness of the upper portion of the chemical treatment tank 51, and the air flow 67 blocks the air curtain 71 to clean the chamber 50. It is possible to prevent the air flow 67 from winding up the dust accumulated on the bottom of the clean chamber 50 and lowering the cleanliness of the upper part of the chemical liquid processing tank 51.

[0013]

By the way, in the case of an overflow type chemical liquid processing apparatus, it is advantageous to quickly remove dust that has entered the chemical liquid and dust generated during chemical liquid processing, and semiconductors and other devices. Indispensable for fine processing such as thin film device manufacturing.

However, even if this is applied to the conventional device shown in FIG. 7 as shown by the phantom line, the air flow of the air curtain 71 is changed between the chemical surface and the outer peripheral wall of the overflow tank 72 on the outer periphery. The turbulence as indicated by the arrow will occur, and this turbulence of the air flow does not generate dust itself, but when a vortex occurs in the air flow, dust entering from the outside stays there and part Since it may reach the upper surface of the processing tank 51, resulting in poor cleanliness, it is difficult to maintain high cleanliness only by securing the downflow of the clean airflow 67.

Therefore, the present invention has as an object to solve such a conventional problem and, in the case where an overflow tank is provided, achieves local exhaust sufficient for safety and hygiene with a minimum exhaust amount, and at the same time, the upper part of the chemical liquid. It is an object of the present invention to provide a clean chemical liquid processing device capable of ensuring downflow of the clean air flow and maintaining high cleanliness of the chemical liquid upper part.

[0016]

In order to achieve the above-mentioned object, the clean chemical liquid processing apparatus of the present invention has a chemical liquid treatment tank and an overflow for collecting the chemical liquid overflowing from the chemical liquid treatment tank in the clean chamber. With a tank,
A clean chemical liquid processing apparatus provided with a clean air supply means for forming a clean air flow from the upper part of the clean chamber toward the upper part of the chemical liquid processing tank, and an exhaust means for locally exhausting the air around the upper part of the chemical liquid processing tank to the outside of the clean room. In the above, in the outer peripheral wall of the overflow tank, an exhaust port for local exhaust by the exhaust means is provided at a position lower than the upper surface of the chemical liquid treatment tank and higher than the recovered chemical liquid surface of the overflow tank. is there.

In this case, it is preferable that the exhaust port is provided all around the outer peripheral wall of the overflow tank.

[0018]

In the above-described structure of the clean chemical liquid processing apparatus of the present invention, a downflow of clean air from the upper part of the clean chamber by the clean air supply means to the upper part of the chemical liquid processing tank is formed in the clean chamber, and at the same time, the exhaust gas is exhausted. The air inside the clean room is exhausted through the exhaust port on the outer peripheral wall of the overflow tank at a position lower than the upper surface of the chemical treatment tank and higher than the recovered chemical surface of the overflow tank without affecting the chemical solution or dust in the overflow tank. This local exhaust is performed so that the air in the clean chamber is drawn into the exhaust port from between the outer peripheral wall of the chemical treatment tank and the outer peripheral wall of the overflow tank, and the clean chamber is downflowed for this local exhaust. Does not disturb the downflow of the clean air that reaches the upper surface of the chemical solution treatment tank, and this downflowing clean air is above the chemical solution treatment tank. After gently reaching the whole area of the chemical solution treatment tank, it flows along the upper surface of the chemical solution treatment tank toward the outer periphery of the upper surface of the chemical solution treatment tank and securely removes locally generated vapor or mist of the chemical solution limited to the upper surface of the chemical solution treatment tank. While constantly updating the top surface with new clean air, the exhaust gas reaches the space between the outer peripheral wall of the chemical solution treatment tank and the outer peripheral wall of the overflow tank and is locally exhausted. It is possible to avoid scattering of mist or mist around, and to prevent dust from entering due to the turbulence of the clean air, and to prevent the dust that has entered from staying on the upper surface of the chemical liquid processing tank. The cleanliness can be kept high.

In this case, if the exhaust port is provided on the entire circumference of the outer peripheral wall of the overflow tank, the flow of clean air that flows down to the outer circumference along the upper surface of the chemical liquid processing tank due to the local exhaust is circumferential. Since it is uniformly performed in each upper portion, it is possible to maintain a high degree of cleanliness evenly over the entire upper surface of the chemical liquid processing tank, and to efficiently and reliably remove harmful vapor and mist with a smaller amount of exhaust gas.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A clean chemical liquid processing apparatus as a first embodiment to which the present invention is applied will be described below with reference to FIGS.

As shown in FIG. 1, the apparatus of the present embodiment is provided with a chemical treatment tank 12 located at the bottom of the clean chamber 10, an overflow tank 13 provided around the chemical treatment tank 12, and an upper portion of the clean chamber 10. A filter and a fan as the clean air supply means 11 are provided.

An exhaust duct as an exhaust means 14 for performing local exhaust is connected to the clean chamber 10 to exhaust local air around the upper surface of the chemical liquid processing tank 12 in the clean chamber 10. , Exhaust is the exhaust treatment device 16
It is designed to be released into the atmosphere after being detoxified.

Then, the chemical solution in the chemical solution processing tank 12 overflows into the surrounding overflow tank 13 and enters into the chemical solution, or dust generated in the chemical solution by the chemical solution treatment in the lift-off process or the like. Purify by always pouring out.

At this time, the above-mentioned dust is mixed in the chemical liquid overflowing into the overflow tank 13, but the dust is removed by the chemical liquid regeneration processing device 15 connected between the overflow tank 13 and the chemical liquid processing tank 12. It is adapted to be regenerated and fed into the chemical liquid treatment tank 12. This avoids wasteful consumption of the chemical solution.

Particularly in this embodiment, the overflow tank 13
An exhaust port 14a for local exhaust by the exhaust means 14 is provided at a position on the outer peripheral wall of the exhaust tank 14 which is lower than the upper surface of the chemical liquid processing tank 12 and higher than the recovered chemical liquid surface of the overflow tank 13.

The local exhaust by the exhaust means 14 will be described below with reference to FIG.

In the clean chamber 10, a downflow of clean air directed from the upper part of the clean chamber 10 by the clean air supply means 11 to the upper part of the chemical treatment tank 12 is formed in a laminar flow state as shown by an arrow 20. . In addition to this, the exhaust means 1
4 makes the air in the clean chamber 10 lower than the upper surface of the chemical solution processing tank 12 on the outer peripheral wall of the overflow tank 13,
Local discharge is performed without affecting the chemical liquid and dust in the overflow tank 13 through the exhaust port 14a located at a position higher than the recovered chemical liquid surface of the overflow tank 13.

This local exhaust is carried out so that the air in the clean chamber 10 is drawn into the exhaust port 14a as shown by the arrow 21 from between the outer peripheral wall of the chemical liquid processing tank 12 and the outer peripheral wall of the overflow tank 13. A laminar flow downflow is carried out in the clean chamber 10 for local exhaust so that the chemical treatment tank 12
Does not disturb the downflow of the clean air arriving at the upper surface of the.

Therefore, after the downflowing clean air quietly reaches the entire upper surface of the chemical treatment tank 12,
It flows along the upper surface of the chemical liquid processing tank 12 to the outer peripheral side of the upper surface of the chemical liquid processing tank 12, and reliably removes locally generated vapor or mist of the chemical liquid limited to the upper surface of the chemical liquid processing tank 12 and always cleans this upper surface with fresh clean air. While reaching the space between the outer peripheral wall of the chemical liquid processing tank 12 and the outer peripheral wall of the overflow tank 13 while being updated at, by being locally exhausted as indicated by an arrow 21,
It is possible to prevent harmful vapors of chemicals and mist from being scattered around by the minimum amount of exhaust by local exhaust, and dust may enter due to the turbulence of the clean air. Therefore, the cleanliness of the upper surface of the chemical liquid processing tank 12 can be kept high without being retained in the part.

A slight turbulence occurs in the air flow in the overflow tank 13 and the upper part of the exhaust duct of the exhaust means 14,
Even if dust enters this part, the chemical solution processing tank 1
It does not reach the upper surface of 2.

Although the dust generated in the overflow tank 13 may enter the overflowed chemical solution, the chemical solution that has entered the overflow tank 13 is dust-removed and regenerated by the chemical solution reprocessing device 15, and then the chemical solution processing tank. Since it is sent to 12, the dust is in the chemical treatment tank 12
It does not enter the inside and adhere to the work to be treated with the chemical solution, resulting in product defects.

Further, the harmful chemical vapor or mist formed on the surface of the chemical treatment tank 12 is the flow of clean air downflowing to the outer periphery along the surface of the chemical treatment tank 12 as shown by the arrow 20. Due to the continuous local exhaustion, the exhaust can be carried away smoothly without turbulence or retention, and can be surely exhausted without scattering to the surroundings. Since exhaust is detoxified by the exhaust treatment device 16, harmful chemical liquid The harmful effects of the steam and mist can be reliably avoided with a small amount of exhaust gas, and the exhaust means 14 and the exhaust treatment device 16 do not have a large capacity, so that the cost can be reduced.

The exhaust port 14a is the overflow tank 1.
When it is provided on the entire circumference of the outer peripheral wall of No. 3, the clean air that flows down in a laminar flow state as indicated by an arrow 20 causes a circular flow of the clean air to the outer circumference along the upper surface of the chemical liquid processing tank 12 by the local exhaust. Since it is evenly performed in each part on the circumference, it is possible to maintain a high degree of cleanliness throughout the upper surface of the chemical liquid processing tank 12 and to remove harmful vapor and mist efficiently and reliably with a smaller amount of exhaust gas. Further, it is possible to achieve further reduction in capacity and cost.

FIG. 3 shows a second embodiment of the present invention, in which the covering wall 17 covering from the air supply part of the clean air supply means 11 to near the upper end of the outer peripheral wall of the overflow tank 13 is made of curtain material or wall material. It is different from the first embodiment in that it is formed.

In this embodiment, the flow of the clean air supplied from the clean air supply means 11 downflows, reaches the upper surface of the chemical liquid processing tank 12, and then reaches the outer peripheral portion along the upper surface of the chemical liquid processing tank 12. To further securely remove the vapor and mist generated on the upper surface of the chemical liquid processing tank 12 as a more solid thing without increasing the flow velocity and pressure of the clean air, and to further prevent the scattering of the mist and mist around the chemical liquid processing tank 12. Therefore, the device does not have a particularly large capacity or a large size.

FIG. 4 shows a third embodiment of the present invention, in which the outer peripheral wall of the overflow tank 13 and the outer peripheral wall of the clean chamber 10 are integrated, and part of this also serves as the cover wall 17 of the second embodiment. I am doing it. This makes the device structure simple and compact.

[0037]

According to the clean chemical treatment apparatus of the present invention,
Local exhaust that does not affect the chemical liquid or dust in the overflow tank through the exhaust port on the outer wall of the overflow tank in the clean chamber, which is lower than the upper surface of the chemical liquid processing tank and higher than the collected chemical liquid surface of the overflow tank. , Without disturbing the downflow of the clean air that reaches the upper surface of the chemical solution treatment tank by downflowing inside the clean chamber, reliably removes locally generated chemical solution vapor and mist limited to the upper surface of the chemical solution treatment tank, and always maintains this upper surface. While updating with new clean air,
Prevents harmful vapors of chemicals and mist from splashing around with the minimum amount of exhaust from local exhaust, and dust enters due to turbulence of clean air, and the entered dusts are placed on the upper surface of the chemical treatment tank. It is possible to maintain the cleanliness of the upper surface of the chemical liquid processing tank 12 at a high level without accumulating it, and it is possible to achieve the chemical liquid processing with a small capacity and a small device in a harmless state with high accuracy.

In this case, the exhaust port is provided on the entire circumference of the outer peripheral wall of the overflow tank, so that the flow of the clean air downflowing to the outer circumference along the upper surface of the chemical liquid processing tank by the local exhaust is performed on each part on the circumference. In addition to maintaining evenly high cleanliness throughout the upper surface of the chemical treatment tank, it is possible to remove harmful vapor and mist efficiently and reliably with a smaller amount of exhaust gas. The property can be further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a clean chemical liquid processing apparatus as a first embodiment to which the present invention is applied.

FIG. 2 is a cross-sectional view showing the flow of supply air and exhaust air around the chemical liquid processing device of the device of FIG.

FIG. 3 is a sectional view showing a clean chemical liquid processing apparatus as a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a clean chemical liquid processing apparatus as a third embodiment of the present invention.

FIG. 5 is a sectional view showing a chemical liquid processing apparatus of a first conventional example.

FIG. 6 is a cross-sectional view showing the flows of supply air and exhaust air in the conventional example of FIG.

FIG. 7 is a sectional view showing a chemical liquid processing apparatus of a second conventional example.

[Explanation of symbols]

 10 Clean Chamber 11 Clean Air Supply Means 12 Chemical Treatment Tank 13 Overflow Tank 14 Exhaust Means 14a Exhaust Port

Claims (2)

[Claims] 1. A clean liquid chamber is provided with a chemical treatment tank and an overflow tank for collecting a chemical liquid overflowing from the chemical treatment tank, and a clean air flow is formed from an upper portion of the clean chamber toward an upper portion of the chemical liquid treatment tank. In a clean chemical liquid processing device equipped with a clean air supply means and an exhaust means for locally exhausting air around the upper part of the chemical liquid processing tank to the outside of the clean chamber, the outer peripheral wall of the overflow tank is lower than the upper surface of the chemical liquid processing tank, and A clean chemical liquid processing device characterized in that an exhaust port for local exhaust by an exhaust means is provided at a position higher than the level of the recovered chemical liquid in the overflow tank. 2. The clean chemical liquid processing apparatus according to claim 1, wherein the exhaust port is provided all around the outer peripheral wall of the overflow tank.