JPH08318169A - Draft device - Google Patents

Abstract

PURPOSE: To provide a draft device by which a harmful gas is hardly retained in a treating chamber. CONSTITUTION: This draft device is set in a clean room and used to treat a semiconductor substrate, etc., with a liq. chemical in a treating chamber 1. Exhaust ports 4 and 5 for exhausting a harmful gas in the treating chamber 1 are provided to the chamber, and the exhaust ports 4 and 5 are covered with a straightening plate 10 having many through-holes 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a draft device used for chemical treatment such as etching of a semiconductor substrate.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor, there are steps of etching a semiconductor substrate and chemically cleaning it. However, since harmful chemicals such as acid chemicals and organic chemicals are used in these steps, A dedicated processing device called a draft device is used. For example, the actual exploitation 57-12363
The conventional drafting device shown in Japanese Patent Laid-Open No. 7-63 and Japanese Patent Laid-Open No. 63-248449 will be described with reference to FIGS.

Reference numeral 1 is a rectangular processing chamber, 2 is a door made of transparent resin or glass provided on the entire surface of the processing chamber 1, and 3 is a chemical liquid tank provided at the bottom of the processing chamber 1 for processing. Accordingly, an acid chemical solution or an organic chemical solution is supplied. Numerals 4 and 5 are exhaust ports formed in the upper and lower portions of the back surface 6 of the processing chamber 1, and numerals 7 and 8 are adjusting plates attached so as to cover a part of the exhaust ports 4 and 5, respectively. It is supported so that its position can be moved in the vertical direction, and by moving these adjusting plates 7 and 8 in the vertical direction, the exhaust port 4,
The exhaust volume is adjusted by changing the opening area of No. 5. Reference numeral 9 denotes an exhaust duct provided on the rear surface side of the processing chamber so as to communicate with the exhaust ports 4 and 5, which is connected to an exhaust fan (not shown) to remove harmful gas such as evaporated chemical liquid from the inside of the processing chamber 1. It is forcibly discharged to the outside through the exhaust ports 4 and 5.

In such a structure, while the semiconductor substrate is immersed in the chemical solution tank 3 and the chemical solution is being processed, the exhaust port 4, the harmful gas evaporated from the chemical solution tank 3 does not leak from the door 2, 5 and exhaust via the exhaust duct 9. Such a draft device constantly sucks the air in the processing chamber 1 through the exhaust ports 4 and 5 and replenishes the door 2 with the sucked air from the outside so that harmful gas does not leak from the door 2. The gap is provided as much as possible. Therefore, even when the apparatus is not used, the harmful gas evaporated from the chemical liquid tank 2 is discharged along with the flow of air.

[0005]

In the conventional example, the
There are two air vents 4, 5 on the back side of the processing chamber.
Since it is only the air flow from the direction of the door 2 to the exhaust ports 4, 5.
Is not smooth, and the exhaust flow is trapped in the upper corners of the processing chamber 1.
May stay. Thus, the exhaust flow due to toxic gas
When the stagnation occurs, open the door 2 and balance the pressure in the processing chamber 1.
When the gas collapsed, the toxic gas that had been
There is a danger of being leaked to. Especially, the draft device
It is installed in a circulating clean room.
For example, if HF (hydrofluoric acid) flows out, the circulation fill
Deteriorates the fiber of the tar and generates dust, resulting in low cleanliness
There is a problem ₂SO_Four(Sulfuric acid) flows out
And S (sulfur) as a component adheres to the silicon substrate
There is a problem that it acts as a donor.

The present invention relates to the improvement of a draft device and solves such a problem.

[0007]

According to a first aspect of the present invention, there is provided a draft device for treating a semiconductor substrate or the like with a chemical solution in a processing chamber, and an exhaust port for exhausting gas inside the processing chamber. And the exhaust port is covered with a straightening plate having a large number of through holes. Further, in the draft device according to the second aspect, the numerical aperture and the opening area of the through hole are different.

[0008]

In other words, the presence of the flow straightening plate allows the exhaust flow toward the exhaust port to smoothly flow, making it difficult for gas to stay in the processing chamber. Further, the gas flow can be made smoother by changing the numerical aperture and the opening area of the through holes.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The same components as those in the conventional example are designated by the same reference numerals, and the description thereof will be omitted. The present invention is different from the conventional example in that a rectifying plate is provided on the entire surfaces of the exhaust ports 4 and 5.

In FIGS. 1 and 2, reference numeral 10 is a straightening plate having an area substantially the same as the back surface 6 of the processing chamber 1, and through holes 11 ... With a diameter of about 10 mm are provided at intervals of 30 mm over the entire surface. 12 ... are spacers for providing a space 13 between the back surface 6 of the processing chamber 1 and the current plate 10, and the current plate 10 is provided with the back surface 6 of the processing chamber 1 via the spacers 12. Fixed to. This fixing method may be any method that can repeatedly attach and detach the flow straightening plate 10, such as screwing or fitting.

In such a structure, the harmful gas in the processing chamber 1 is sucked into the space 13 in every corner by the through holes 11 provided in the straightening plate 10 and reaches the exhaust ports 4 and 5, so that, for example, Therefore, no harmful gas is accumulated in the corner of the processing chamber 1. Since the rectifying plate 10 is removable, another rectifying plate having a different size and arrangement of the through holes 11 ... Can be prepared as a spare, and can be appropriately replaced according to the exhaust capacity and the chemical solution used. .

The sizes of the through holes 11 are not required to be uniform, and may be appropriately changed within one straightening plate 10 so that gas is unlikely to stay in the processing chamber 1. . For example, since the gas tends to stay in the corner portion of the processing chamber 1, the size of the outer through hole 11 may be made larger than that of the inner through hole as shown in FIG. The rectifying plate 10 as shown in FIG.
2 may be used instead of the straightening vane 10, or the straightening vanes of FIGS. 2 and 3 may be replaced as appropriate according to the exhaust capacity and the chemical liquid used.

Further, as shown in FIG. 4, even if the through holes 11 ... Are capped 14 ... The same effect can be obtained.

[0014]

In the draft device of the present invention, the presence of the flow straightening plate allows the exhaust flow toward the exhaust port to flow smoothly and makes it difficult for the gas to stay in the processing chamber. Can be prevented from leaking out, and indoor air such as a clean room where the device is installed can be kept clean.

In particular, in the draft device according to the second aspect, the number of openings and the opening area of the through holes are made different to make the gas flow smoother, so that the above effect is further promoted. You can

[Brief description of drawings]

FIG. 1 is a side sectional view showing an internal structure of a draft device according to an embodiment of the present invention.

FIG. 2 is a plan view of a current plate according to an embodiment of the present invention.

FIG. 3 is a plan view of a current plate according to another embodiment of the present invention.

FIG. 4 is a plan view of a current plate according to another embodiment of the present invention.

FIG. 5 is a perspective view showing the internal structure of a conventional draft device.

FIG. 6 is a front view of the rear surface of the processing chamber of the draft device in the conventional example.

FIG. 7 is a side sectional view showing the internal structure of a conventional draft device.

[Explanation of symbols]

 1 processing chamber 4, 5 exhaust port 10 straightening plate 11 through hole

Claims (2)

[Claims] 1. A method of processing a semiconductor substrate or the like using a chemical solution in a processing chamber, wherein the processing chamber is provided with an exhaust port for exhausting gas in the chamber, and the exhaust port is provided with a large number of through holes. A draft device, which is covered with a current plate. 2. The draft device according to claim 1, wherein the through holes have different numerical apertures and opening areas.