JPH08303676A - Harm removing treatment piping - Google Patents

Abstract

PURPOSE: To effectively discharge gas used in the manufacturing process of a semiconductor to a harm removing treatment device by interposing a pressure control valve and an orifice in series in a pipe line in a harm removing treatment piping in which gas is allowed to flow to the harm removing treatment device side by an approximately constant flow rate. CONSTITUTION: In a harm removing treatment piping for supplying toxic, explosive and danger reactive gas A to a semiconductor manufacturing device of a reactor, a regulator valve RV1 for decreasing the secondary side pressure according to the fluctuation of primary side pressure and maintaining it to the specified pressure and an orifice O1 are pipingly connected in series downstream from a valve V3 when gas A remaining in a pipe line (h) in changing of a cylinder is removed and discharged, and a harm removing treatment device E is directly connected downstream from it. The orifice O1 is so provided as to allow gas whose pressure is decreased after passing the regulator valve RV1 the flow to the harm removing treatment device E by the constant flow rate. Therefore, the fluctuation of the flow rate can be reliably restrained, and the treatment efficiency can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abatement treatment pipe for discharging a gas used in a semiconductor manufacturing process to an abatement treatment apparatus.

[0002]

2. Description of the Related Art In the manufacturing process of semiconductors, various kinds of toxic and explosive dangerous reaction gases are used. After use, these gases are sent to a detoxification treatment device to be detoxified and then discharged to the outside.

For example, there is an abatement treatment pipe shown in FIG.
Here, the gas A is normally supplied to the semiconductor manufacturing apparatus F side such as a reaction furnace with the valve V ₁ opened and the valve V ₂ closed. However, when the gas A disappears after that and the cylinder needs to be replaced, or when it is necessary to replace it with another gas, the gas A remaining in the conduit h (between the main valve of the tank and the valve V ₂ ) Need to be removed and discharged. At this time, the valve V ₁ is closed and the valves V ₂ and V ₃ are opened.
Since the residual pressure is as high as about 150 kgf / cm ² which is the same as the internal pressure of the cylinder, the pressure is temporarily reduced by the buffer tank B. Further, the gas A is introduced into the abatement processing device E by the vacuum suction device D.

However, since the detoxification processing device E has a processing capacity per hour, even if a large amount of gas is sent at one time, the capacity will be exceeded and the processing cannot be completed, and if it is continued to be sent, the efficiency may decrease. However, the valve V ₃
On the contrary, if a small amount of gas is sent by squeezing the gas, it takes too much processing time, resulting in poor efficiency. Therefore, it is preferable that the flow rate corresponding to the maximum processing capacity of the abatement processing apparatus E is simply kept constant. Therefore, conventionally, the mass flow controller C
Was used to control the gas A to an optimum flow rate and then sent to the harm removal treatment apparatus E.

[0005]

The mass flow controller C is roughly divided into three elements, which are a thermal mass flow meter, a flow rate control valve and a control circuit section. The thermal mass flow meter uses a sensor pipe having an extremely small diameter, and the opening / closing amount of the valve body and the valve seat of the flow control valve is minute (micron order). Both of them are important components for controlling the flow rate. On the other hand, since the gas A is mainly a highly reactive gas, reaction products are likely to be generated, and in particular, the gas A is generated in the sensor pipe and the on-off valve portion described above. And may get stuck. In particular, even if the sensor pipe is narrowed by a few microns, it directly affects the flow rate control, so the flow rate of the mass flow controller C changes and the flow rate sent to the abatement processing device E fluctuates (often becomes an excessive flow rate). .

In addition, since mass flow controllers are generally expensive, they are not preferable for constructing a low cost piping system.

The present invention is intended to solve the above problems, and an object thereof is to provide an extremely efficient and inexpensive detoxification treatment pipe without causing fluctuations in flow rate due to reaction products. And

[0008]

According to the present invention, in a detoxification treatment pipe in which gas is allowed to flow into a detoxification treatment device side at a substantially constant flow rate, a pressure regulating valve (regulator valve) and an orifice are provided in a pipe line. It is a detoxification treatment pipe that is connected in series and sent to the abatement treatment device.

Decompression relief means for temporarily decompressing the high pressure gas on the gas cylinder side may be provided on the primary side of the pressure control valve, and vacuum suction means may be provided on the secondary side of the orifice. Further, it is desirable to combine the pressure regulating valve and the orifice in one valve body.

[0010]

The pressure adjusting valve (the same applies to the regulator valve below) functions to keep the secondary pressure, that is, the inlet pressure of the orifice, at a low pressure in response to fluctuations in the primary pressure of the high pressure. The outlet side of the orifice is connected to a detoxification treatment device, a vacuum pump, or the like, and the pressure is almost constant. Therefore, there is a substantially constant differential pressure before and after the orifice, and a substantially constant gas flow rate can be sent to the abatement treatment device side.

The pressure on the primary side of the pressure regulating valve gradually drops, but since this regulating valve is a so-called self-powered type, once the secondary side pressure is set, control on the way is not required and the primary side and the secondary side are not required. It functions so that the set pressure can be obtained until there is no pressure difference, so it is easy to handle. There are many types and specifications of this pressure control valve, and an orifice is easily available. Therefore, if the set pressure of these pressure control valves and the orifice diameter are appropriately selected, an efficient flow rate is selected according to the processing capacity and situation of each abatement processing device, and the abatement processing is performed within a shorter time. I can finish.

Although it is unavoidable that reaction products are also generated in the pressure regulating valve and the orifice, it does not become a functional problem when they are produced in the order of microns. Since the piping system is simple and the prices of the components themselves are low, the cost of the abatement treatment piping is low.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a piping diagram showing an example of detoxification treatment piping, FIG.
FIG. 8 is a piping diagram showing another embodiment of the present invention. The same components as those in the piping example shown in FIG. 4 are designated by the same reference numerals.
First, from FIG. 1, the outline of the abatement treatment pipe is the same as the conventional one, but a regulator valve RV ₁ and an orifice O ₁ are connected in series on the downstream side of the valve V ₃ , and the abatement treatment device E is provided on the downstream side. Is a direct connection. The regulator valve RV is a self-powered pressure regulating valve, and here, a pressure reducing valve (1
A secondary pressure of 250 kgf / cm ² and a secondary pressure of −76 cmHg to 3 kgf / cm ² ) are used.

The pressure adjusting valve can be set to reduce the secondary pressure in response to fluctuations in the primary pressure of the high pressure so that the pressure becomes constant. Orifice O ₁
Also, a commercially available product can be used, and the gas lowered to a constant pressure through the regulator valve is made to flow to the abatement processing device E at a constant flow rate. Therefore, the gas A remaining in conduit h is reduced to the set pressure through the valves V _1, through the orifice O ₁ is sent to a detoxification treatment apparatus E at a constant flow rate.

Next, FIG. 2 shows another embodiment, but the outline of the detoxification treatment pipe is the same as above. However, in the above example, depending on the opening degree and flow rate of the orifice, the pressure on the secondary side of the regulator valve may be a very low value.Therefore, the regulator valve alone should be used to stably control the pressure on the secondary side. Can be difficult. In order to prevent this, in FIG. 2, a means for temporarily reducing the pressure of the high pressure gas on the gas cylinder side, for example, a buffer tank B, is provided between the primary side of the regulator valve, specifically between the valves V ₂ and V ₃ .
It is possible to stabilize the secondary pressure by lowering the pressure.

The orifice O ₂ is no functions similarly to the above example, a vacuum generator D as a vacuum suction means on the secondary side of the orifice O ₂ provided, the differential pressure across the orifice O ₂ becomes more constant Therefore, a constant flow rate of gas is sent to the abatement processing apparatus E. P ₁ and P ₂ may be provided with pressure gauges for the pressures on the primary side and the secondary side of the regulator valve RV ₂ so that they can be taken out.

With respect to the gas A remaining in the conduit h as described above, when the valve V ₁ is closed and the valves V ₂ and V ₃ are opened, the high pressure gas is decompressed in the buffer tank B and introduced into the regulator valve RV ₂ . It is reduced to the set pressure by this,
After passing through the orifice O ₂ , it is sent to the abatement treatment device E at a constant flow rate through the vacuum generator D.

A regulator valve RV ₃ shown in FIG. 3 has an orifice O ₃ inside a joint G, and the joint G is screwed and welded into a connection port of the valve. This is an example in which an orifice is integrally combined with the valve body. This is convenient because the piping system can be more simply and compactly assembled.

Next, an experiment was conducted on this detoxification treatment pipe. The results are shown in FIGS. 4 (a) and 4 (b). [Experimental Example 1] Regarding the abatement treatment pipe shown in FIG. 2 (however, the gas tank A, the valve V ₁ and the abatement treatment device E are excluded), N ₂ is used to put PB = 10 kgf / c in the buffer tank B.
A secondary flow rate Q of the orifice O ₂ was measured with a mass flow meter by enclosing m ² and 500 cc. Flow rate Q and time T at this time
Also, the characteristics of the primary pressure P _{1 of the} regulator valve RV ₂ and the time T were measured. The secondary set pressure P ₂ of the regulator valve RV ₂ was 74 Torr, and the orifice diameter of the orifice O ₂ was φ0.5 mm. The result at this time is shown in FIG. In this way, the secondary side flow rate Q = 2.3 l / min was made to flow constantly for about 130 seconds, and N ₂ in the buffer tank could be made to flow off at a substantially constant flow rate.

[Experimental Example 2] Next, the same experimental data as the above was taken by changing the orifice O ₂ . However, the secondary set pressure P ₂ of the regulator valve RV ₂ was 710 Torr, and the orifice diameter of the orifice O ₂ was φ0.32 mm. The result at this time is shown in FIG. In this case, the secondary side flow rate Q is approximately 500
It could be kept constant at cc / min, and it could be flowed for about 550 seconds to drain almost all the amount. In both of the above examples, the obtained flow rate characteristics are almost the same as the characteristics when the conventional mass flow controller is used.

[0021]

According to the present invention, it is possible to provide an efficient and inexpensive detoxification treatment pipe with a simple component structure.

[Brief description of drawings]

FIG. 1 is a piping diagram showing an embodiment of the abatement treatment piping of the present invention.

FIG. 2 is a piping diagram showing another embodiment of the abatement treatment piping of the present invention.

FIG. 3 is a partial cross-sectional view showing an example in which a regulator valve and an orifice are combined.

FIG. 4 is a characteristic diagram of performance test data of a detoxification treatment pipe according to the present invention, showing a primary pressure and time and a secondary flow rate and time.

FIG. 5 is a piping diagram showing an example of a conventional abatement treatment piping.

[Explanation of symbols]

A ... Gas B ... Buffer tank C ... Mass flow controller D ... Vacuum generator E ... Detoxification treatment device F ... Semiconductor manufacturing device O ... Orifice V ... Open / close valve RV ... Regulator valve G ... Joint

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Kawashima 2 Daifuku, Hitachi Metals Co., Ltd. Kuwana City, Mie Prefecture Hitachi Metals Co., Ltd. Kuwana Plant (72) Inventor Toru Matsuoka 2 Daifuku, Kuwana City, Mie Prefecture Hitachi Metals Co., Ltd. Kuwana Plant ( 72) Inventor Makoto Ishikawa 2 Daifuku, Kuwana City, Mie Hitachi Metals Co., Ltd. Kuwana Factory

Claims (3)

[Claims] 1. A detoxification treatment pipe in which a gas is caused to flow to a detoxification treatment device side at a substantially constant flow rate, in which a pressure regulating valve and an orifice are piped in series in a pipe line and sent to the detoxification treatment device. The detoxification treatment pipe characterized in that 2. A pressure reducing valve for temporarily reducing the high pressure gas on the gas cylinder side is provided on the primary side of the pressure control valve, and a vacuum suction means is provided on the secondary side of the orifice. Item 1. The harm removal treatment pipe according to item 1. 3. The harm removal treatment pipe according to claim 1, wherein the pressure regulating valve and the orifice are combined in one valve body.