JPH1163361A - Exhaust piping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent heat transmission to a sensor so as to carry out accurate measurement by arranging the sensor in an exhaust pipe via a branch pipe, a gate valve in the midway of the branch pipe, and a heater in the upstream beyond the gate valve in the branch pipe. SOLUTION: In a main exhaust pipe 7, the first branch pipe 12 and the second branch pipe 13 are connected to the upstream of a connection part between an auxiliary exhaust pipe 10 and the main exhaust pipe 7. The first branch pipe 12, in which the first gate valve 14 is arranged, is provided with a Baratron 15. The second branch pipe 13, in which the second gate valve 21 is arranged, is provided with a Pirani gauge 16. On the outer circumferences of the first branch pipe 12 and the first gate valve 14, the first branch pipe heater 19 is wound until it reaches the Baratron 15, while on the outer circumference of the second branch pipe 13 to the second gate valve 12, the second branch pipe heater 20 is wound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust piping device, and more particularly to an exhaust piping device in a case where solidified components are contained in exhaust gas.

[0002]

2. Description of the Related Art Exhaust gas exhausted from various types of processing equipment may contain solidified components that solidify in the exhaust gas. It is necessary to prevent solidification.

[0003] As a processing apparatus containing a solidified component in exhaust gas, there is a semiconductor manufacturing apparatus. In a semiconductor manufacturing apparatus for producing a Si ₃ N ₄ film, N ₂ is contained in exhaust gas as a reaction by-product.
H ₄ Cl is contained, and the NH ₄ Cl has a high solidification temperature and becomes solid at room temperature. When NH ₄ Cl flows back into the reaction chamber, the NH ₄ Cl adheres to the wafer as particles and reduces the processing quality, reliability, and yield of the wafer.

Therefore, conventionally, the exhaust pipe is heated so that the reaction by-product does not adhere to the pipe and solidify.

Referring to FIG. 2, a description will be given of a conventional exhaust piping device of a semiconductor manufacturing apparatus.

A cylindrical external reaction tube 1 having an upper end closed and an open lower end is provided inside a heater (not shown). Inside the outer reaction tube 1, an internal reaction tube 2 having an open upper end is provided. Are disposed concentrically with the external reaction tube 1, and the lower ends of the outer reaction tube 1 and the inner reaction tube 2 are supported by a furnace port flange 3. An O-ring is provided between the outer reaction tube 1 and the furnace port flange 3. 5 and a reaction chamber 4 is defined by the internal reaction tube 2. The lower end opening of the furnace port flange 3 is hermetically closed by a seal cap 6, and the seal cap 6 is moved up and down by a boat elevator (not shown) to open and close the lower end opening of the furnace port flange 3. A boat (not shown) is erected on the seal cap 6, and wafers are loaded in multiple stages in a horizontal posture. A reaction gas introduction pipe (not shown) is connected to a lower portion of the furnace port flange 3 so as to communicate with the inside of the internal reaction pipe 2.

The main exhaust pipe 7 is connected to the furnace port flange 3 so as to communicate with a lower end of a cylindrical space 8 formed between the external reaction pipe 1 and the internal reaction pipe 2. The main exhaust pipe 7 is provided with a main exhaust valve 9, and a sub exhaust pipe 10 is communicated with the upstream side of the main exhaust pipe 7 and the downstream side of the main exhaust valve 9. The exhaust pipe 10 has a sub exhaust valve 1
1 is provided.

[0008] A first branch pipe 12 and a second branch pipe 13 are connected to the main exhaust pipe 7 upstream of a connection between the sub exhaust pipe 10 and the main exhaust pipe 7. The first branch pipe 12 is provided with a first gate valve 14, and the first branch pipe 12 is provided with a baratron 15. The second branch pipe 13 is provided with a Pirani gauge 16.

A main exhaust pipe heater 17 is wound around an outer periphery of the main exhaust pipe 7 from a connection portion of the main exhaust pipe 7 to the furnace port flange 3 to the main exhaust valve 9, and the sub exhaust is provided. A sub-exhaust pipe heater 18 is wound around the outer circumference of the sub-exhaust pipe 10 up to the valve 11, and a first branch pipe heater 19 is provided on the outer circumference of the first branch pipe 12 and the first gate valve 14. A second branch pipe heater 20 is wound around the outer circumference of the second branch pipe 13 until it reaches the Pirani gauge 16.

[0010] The boat (not shown) is moved by the boat elevator (not shown) through the seal cap 6.
And the boat is loaded with wafers. After loading, the boat is loaded into the internal reaction tube 2 by the boat elevator. After the lower end of the furnace port flange 3 is completely sealed by the seal cap 6, the auxiliary exhaust valve 11 is opened with the exhaust valve 9 closed, and the reaction is gently performed through the auxiliary exhaust pipe 10. The inside of the chamber 4 is evacuated.
When the pressure inside the reaction chamber 4 drops to a required pressure, the sub exhaust valve 11 is closed, and the main exhaust valve 9 and the first gate valve 1 are closed.
4 is opened, the inside of the reaction chamber 4 is exhausted through the main exhaust pipe 7, and the heater (not shown) is always energized to heat the inside of the reaction chamber 4. The inside of the reaction chamber 4 is evacuated while measuring the pressure in the reaction chamber 4 by the Pirani gauge 16.

When the vacuum is evacuated to a predetermined pressure, a predetermined process such as introducing a reaction gas to form a film on the wafer surface is performed.
The exhaust gas containing the reaction by-product after the reaction is passed through the main exhaust pipe heater 17, the sub exhaust pipe heater 18, the first branch pipe heater 19, and the second branch pipe heater 20, and The main exhaust pipe 7, the sub-exhaust pipe 10, the first branch pipe 12, and the second branch pipe 13 are exhausted through the main exhaust pipe 7 in a state where the main exhaust pipe 7, the second branch pipe 13, and the second branch pipe 13 are heated to a reaction by-product solidification temperature or higher.

When the treatment is completed, the introduction of the reaction gas is stopped, an inert gas such as nitrogen gas is introduced into the reaction chamber 4, the gas is purged, and the pressure in the reaction chamber 4 is measured by the baratron 15. Meanwhile, the inside of the reaction chamber 4 is returned to normal pressure. Thereafter, the seal cap 6 is opened, and the boat (not shown) is pulled out by the boat elevator (not shown).

[0013]

SUMMARY OF THE INVENTION In the above prior art,
The second branch pipe 1 is heated by the second branch pipe heater 20.
3 is heated up to just before the Pirani gauge 16,
Heat is also transmitted to the Pirani gauge 16, and the Pirani gauge 16 is heated. The Pirani gauge 16 has a characteristic that when heat is transmitted from a gas other than the gas whose pressure is to be measured, the measured value is not accurate. Therefore, when the reaction chamber 4 is evacuated, the Pirani gauge 16 is heated. Then
There is a problem that the pressure control of the reaction chamber 4 cannot be performed with high accuracy.

In view of such circumstances, the present invention is intended to prevent heat from being transmitted from a gas other than the gas to be measured to a sensor in an exhaust piping device, and to perform accurate measurement.

[0015]

SUMMARY OF THE INVENTION The present invention relates to an exhaust pipe system for heating an exhaust pipe, wherein a sensor is provided on the exhaust pipe via a branch pipe, a gate valve is provided in the middle of the branch pipe, and the branch pipe is provided. The present invention relates to an exhaust piping device provided with a heater upstream of the gate valve to prevent heat from being transmitted from the heater to the sensor.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, components having the same functions as those shown in FIG. 2 are denoted by the same reference numerals.

Inside the heater (not shown), there is provided a tubular external reaction tube 1 having an upper end closed and an open lower end. Inside the outer reaction tube 1, an internal reaction tube 2 having an open upper end is provided. Are disposed concentrically with the external reaction tube 1, and the lower ends of the outer reaction tube 1 and the inner reaction tube 2 are supported by a furnace port flange 3. An O-ring is provided between the outer reaction tube 1 and the furnace port flange 3. 5 and a reaction chamber 4 is defined by the internal reaction tube 2. The lower end opening of the furnace port flange 3 is hermetically closed by a seal cap 6, and the seal cap 6 is moved up and down by a boat elevator (not shown) to open and close the lower end opening of the furnace port flange 3. A boat (not shown) is erected on the seal cap 6, and wafers are loaded in multiple stages in a horizontal posture. A reaction gas inlet pipe (not shown) is provided below the furnace port flange 3.
Are connected so as to communicate with the inside of the internal reaction tube 2.

The main exhaust pipe 7 is connected to the furnace port flange 3 so as to communicate with a lower end of a cylindrical space 8 formed between the external reaction pipe 1 and the internal reaction pipe 2. The main exhaust pipe 7 is provided with a main exhaust valve 9, and a sub exhaust pipe 10 is communicated with the upstream side of the main exhaust pipe 7 and the downstream side of the main exhaust valve 9. The exhaust pipe 10 has a sub exhaust valve 1
1 is provided.

A first branch pipe 12 and a second branch pipe 13 are connected to the main exhaust pipe 7 upstream of a connection between the sub exhaust pipe 10 and the main exhaust pipe 7. The first branch pipe 12 is provided with a first gate valve 14, and the first branch pipe 12 is provided with a baratron 15. Further, the second branch pipe 13 is provided with a second gate valve 21 and the second branch pipe 1
3 is provided with a Pirani gauge 16.

A main exhaust pipe heater 17 is wound around the outer periphery of the main exhaust pipe 7 from the connection portion of the main exhaust pipe 7 to the furnace port flange 3 to the main exhaust valve 9, and the sub exhaust is provided. A sub-exhaust pipe heater 18 is wound around the outer circumference of the sub-exhaust pipe 10 up to the valve 11, and a first branch is formed on the outer circumference of the first branch pipe 12 and the first gate valve 14 until the baltron 15 is reached. A tube heater 19 is wound, and a second branch tube heater 20 is wound around the outer circumference of the second branch tube 13 up to the second gate valve 21.

The boat (not shown) is moved by the boat elevator (not shown) through the seal cap 6.
And the boat is loaded with wafers. After loading, the boat is loaded into the internal reaction tube 2 by the boat elevator. After the lower end of the furnace port flange 3 is completely sealed by the seal cap 6, the auxiliary exhaust valve 11 is opened with the exhaust valve 9 closed, and the reaction is gently performed through the auxiliary exhaust pipe 10. The inside of the chamber 4 is evacuated.
When the pressure inside the reaction chamber 4 drops to a required pressure, the sub exhaust valve 11 is closed, and the main exhaust valve 9 and the first gate valve 1 are closed.
4 is opened, the inside of the reaction chamber 4 is exhausted through the main exhaust pipe 7, and the heater (not shown) is always energized to heat the inside of the reaction chamber 4. Open the second gate valve 21,
The inside of the reaction chamber 4 is evacuated while measuring the pressure in the reaction chamber 4 by the Pirani gauge 16.

The use of the Pirani gauge 16 depends on the reaction chamber 4
Since the inside is evacuated only, the second gate valve 21 is closed before evacuation or after evacuation to a predetermined pressure. The processing of the wafer is performed in a state where the second gate valve 21 is closed, and a predetermined processing such as introducing a reaction gas through the reaction gas introduction pipe (not shown) to form a film on the wafer surface is performed. During the introduction of the reaction gas, the main exhaust pipe heater 1
7, sub exhaust pipe heater 18, first branch pipe heater 1
9 and the second branch pipe heater 20, the main exhaust pipe 7, the sub exhaust pipe 10, the first branch pipe 12, and the second branch pipe 13 are heated to a temperature equal to or higher than the reaction by-product solidification temperature. In this state, the exhaust gas is exhausted through the main exhaust pipe 7 without the reaction by-products in the exhaust gas solidifying. The transfer of heat from the second branch pipe heater 20 to the Pirani gauge 16 is blocked by the second gate valve 21.

When the process is completed, the introduction of the reaction gas is stopped, an inert gas such as a nitrogen gas is introduced into the reaction chamber 4, the gas is purged, and the pressure in the reaction chamber 4 is measured by the Baratron 15. While evacuation in the furnace and introduction of nitrogen gas in the furnace are repeated several times, nitrogen gas is introduced into the furnace until the inside of the furnace finally reaches atmospheric pressure. The closing of the first gate valve 14 is performed in an event before the event of introducing nitrogen gas into the furnace until the inside of the furnace reaches atmospheric pressure. After the inside of the reaction chamber 4 is returned to normal pressure, the seal cap 6 is opened, and the boat (not shown) is drawn out by the boat elevator (not shown).

In the above-described embodiment, the case where the present invention is applied to a semiconductor manufacturing apparatus has been described. However, it is needless to say that the present invention can be applied to various apparatuses in which components that easily liquefy and solidify at high temperatures are contained in exhaust gas. Nor. The target sensor is not limited to the Pirani gauge, but may be another sensor having no heat resistance, such as an atmospheric pressure sensor.

[0026]

As described above, according to the present invention, when the heater is energized, a gate valve upstream of the sensor, which does not have heat resistance, is provided in the exhaust piping device, so that heat is supplied from the heater to the sensor. Can be prevented from being transmitted,
Accurate measurement can be performed, the length of the unheated portion of the pipe leading to the sensor can be reduced, and the exhaust gas is cooled during the introduction of the reaction gas, and the reaction by-products in the exhaust gas are reduced. Various excellent effects are exhibited, for example, solidification of the substance and prevention of reaction by-products adhering to the sensor.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 External reaction tube 2 Internal reaction tube 7 Main exhaust pipe 13 Second branch pipe 16 Pirani gauge 20 Second branch pipe heater 21 Second gate valve

Claims (1)

[Claims] In an exhaust pipe apparatus for heating an exhaust pipe, a sensor is provided in the exhaust pipe via a branch pipe, a gate valve is provided in the middle of the branch pipe, and a heater is provided upstream of the gate valve of the branch pipe. An exhaust piping device comprising: