JP2866691B2 - Processing equipment and heat treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a processing apparatus and a heat treatment apparatus.

(Prior Art) Japanese Patent Application Laid-Open No. 62-63421 discloses a system in which a pressure and a flow velocity in an exhaust pipe are detected, and a flow control valve provided in the exhaust pipe is adjusted via a control device to uniformly exhaust the inside of the apparatus. , JP-A-63-2
38281 and JP-A-63-304620.

Further, Japanese Patent Application Laid-Open No. Sho 58-124226 discloses an apparatus for making the pressure of exhaust gas from the apparatus constant at the level of the liquid column.

(Problems to be Solved by the Invention) The technology of the former document has a complicated structure of the device, is expensive, and requires maintenance of the device frequently in a device in which products adhere to the exhaust system. It has improvements such as not to be.

The latter technique has an improvement in that the exhaust gas is not discharged through the liquid column provided in the exhaust system unless the pressure in the apparatus becomes positive pressure, and the gas flow in the apparatus is not uniform.

(Object of the Invention) The present invention has been made in view of the above points, and has an object to provide a processing apparatus and a heat treatment apparatus which are capable of uniform exhaustion with a simple structure and have no disturbance in gas flow in the apparatus. .

(Summary of the Invention) The present invention relates to a processing apparatus having a mechanism for exhausting gas through an exhaust pipe, wherein a tributary pipe is provided in the middle of the exhaust pipe, and the tributary pipe is opened and closed by a pressure difference from the atmosphere to open and close the exhaust pipe. It is characterized in that a movable valve for flowing the atmosphere is provided so as to maintain the pressure at a predetermined value.

In this case, the end of the tributary pipe is downwardly opened to the atmosphere, and the movable valve is provided in the enormous concave portion provided at the end so as to be closed by its own weight and to be opened by the pressure difference from the atmosphere. Preferably.

The present invention also provides a heat treatment apparatus having a mechanism for exhausting gas through an exhaust pipe, wherein a branch pipe is provided in the middle of the exhaust pipe, and the inside of the exhaust pipe is predetermined by opening and closing the branch pipe by a pressure difference from the atmosphere. It is characterized in that a movable valve for flowing the atmosphere is provided so as to maintain the pressure.

(Operation) According to the present invention, a branch pipe is provided in the middle of the exhaust pipe, and the branch pipe is opened and closed by a pressure difference from the atmosphere to allow the air to flow into the exhaust pipe so as to maintain the inside of the exhaust pipe at a predetermined pressure. Since the valve is provided, uniform exhaust can be performed with a simple configuration, and uniform processing can be performed.

(Example) Hereinafter, an example in which the present invention is applied to a vertical heat treatment apparatus will be specifically described with reference to the drawings.

The vertical process tube 10 is made of a heat-resistant material, for example, a quartz tube.

A cylindrical heater 16, for example, a resistance heating type heater is provided around the process tube 10.
Can be appropriately set at a predetermined heat treatment temperature, for example, in the range of 800 to 1200 ° C.

A large number of wafers 18 are loaded into the process tube 10 as objects to be processed, and these wafers are stored in a heat-resistant, for example, quartz wafer boat 17, and the boat 17 is placed on a mounting table 19, and the above-described process is performed. It is stored in a predetermined position in the tube 10.

The mounting table 19 is installed on the lid 14, and the lid 14 can be moved up and down by a lifting mechanism (not shown) so that the wafer 18 can be loaded and unloaded.

A processing gas is supplied to the introduction pipe 12 via a mass flow controller 30.

In this embodiment, the exhaust driving of the plurality of process tubes 10 is performed by a single exhaust fan 20 having a large exhaust capacity disposed in the common exhaust pipe 23. The exhaust fan 20 may be a vacuum pump.

A characteristic configuration of this embodiment is that a branch pipe 40 is disposed in the middle of each exhaust pipe 22 corresponding to the plurality of process tubes 10. The details of the branch pipe 40 will be described with reference to FIG.

That is, the tributary pipe 40 is composed of a pipe 48 that is bent downward, for example, from the middle of the exhaust pipe 22 and whose end is open to the atmosphere with the end directed downward.A huge concave portion 46 is provided in the end of the pipe 48. The movable valve 42 is provided in the concave portion 46 so as to be closed by its own weight and open with a pressure difference from the atmosphere.

An O-ring 44 is provided on the lower edge of the concave portion 46 to seal the space between the branch pipe and the atmosphere in an airtight manner by pressing the movable valve 42 by its own weight.

 Next, the operation of the above embodiment will be described.

When the processing gas flows through one of the process tubes 10 and the processing gas does not flow through the other process tubes 10 and the lid 14 is closed, the exhaust fan 20 exhausts air. Since the flow rate of the processing gas flowing with respect to the capacity is small, the pressure in the exhaust pipe 22 is largely negative.

As a result, the force of the differential pressure applied to the movable valve 42 becomes larger than the weight of the movable valve 42, the movable valve 42 rises greatly, the atmosphere flows into the exhaust pipe 22 through the concave portion 46, and the pressure in the exhaust pipe 22 is Always maintained at a defined pressure.

The desired pressure can be obtained by changing the weight per unit area of the movable valve 42. For example, if the pressure difference from the atmosphere is −10 mmH ₂ O, the desired pressure is 1 atmosphere = 10000 mmH ₂ O = 1 kg / cm ² . Depending on the relationship, the weight of the movable valve 42 may be set to 1 g / cm ² . Movable valve 42
The weight of the movable valve 42 may be adjusted by changing the material and thickness of the movable valve 42.
When the wafer is oxidized or diffused, the pressure difference between the wafer and the atmosphere in the exhaust pipe 22 is -1 to -20 mm.
H ₂ O range. Therefore, a desirable pressure in the exhaust pipe 22 for performing uniform exhaust is within the above pressure range.

Next, when the lid 14 is opened to carry the wafer into another process tube 10, a large amount of air flows from the process tube 10 into the exhaust pipe 22, and the pressure in the exhaust pipe 22 rises. At this time, the movable valve of the tributary pipe 40 that has been widely opened until now
The opening degree of the opening 42 becomes narrow, and it is stabilized in a state where a desired pressure is obtained. As described above, the opening degree of the movable valve 42 of the branch pipe 40 is
It changes according to the internal pressure and operates so that the desired pressure is always maintained. Even when the flow rate of the gas flowing through the process tube 10 is changed in order to change the process state, the movable valve 42 of the branch pipe 40 operates and the desired pressure is always maintained in the same manner as described above.

Therefore, the process gas flowing in the process tube 10 can be uniformly exhausted, so that the gas flow in the apparatus is not disturbed, and the uniformity between the in-plane and in-plane surfaces of the processed wafer can be satisfactorily processed.

Note that the present invention is not limited to the above embodiment,
Various modifications can be made within the scope of the present invention.

The present invention is not necessarily applied to the case where the exhaust driving source is commonly used for the plurality of process tubes 10, and even when the exhaust pipe 22 is provided exclusively for the single process tube 10, the process may be performed. In some cases, the flow rate of the processing gas is changed in order to change the state, or the performance of the exhaust fan 20 is changed due to fluctuations in the power supply voltage, and the like.

The automatic control exhaust device shown in the above-mentioned literature has an improvement point that it is generally difficult to adjust a wide pressure range, but a significant improvement can be made by using the present invention in combination. it can.

It is also useful in practicing the present invention that the weight of the movable valve 42 can be adjusted so that the movable valve 42 of the branch pipe 40 opens and closes at a desired pressure, or the movable valve 42 is pushed or pulled by a spring. It is.

When the present invention is used in an apparatus in which a corrosive gas such as HCl flows at a high temperature such as an oxidation furnace and a diffusion furnace, the exhaust pipe 22 and the branch pipe are used.
It is also useful in practicing the present invention that the portion that comes into contact with the 40 processing gases is made of a nonmetal such as fluororesin.

Also, a valve is connected to the branch pipe 40 to finely adjust the pressure to a desired value.
Exhaust pipe 22 between the process tube 10 and the tributary pipe
It is also useful to attach to the exhaust pipe 22 between 40 and the common exhaust pipe 23.

Further, the present invention is not limited to a heat treatment furnace such as an oxidation furnace or a diffusion furnace, but may be applied to a normal pressure CVD apparatus, a sprinkler apparatus, and other normal pressure processing apparatuses.

Naturally, the present invention can be applied not only to the vertical apparatus but also to a horizontal apparatus such as a horizontal heat treatment furnace.

〔The invention's effect〕

As described above, according to the present invention, a tributary pipe is provided in the middle of an exhaust pipe, and the tributary pipe is opened and closed by a pressure difference from the atmosphere to flow the atmosphere so as to maintain the inside of the exhaust pipe at a predetermined pressure. , A uniform exhaust can be achieved with a simple configuration, and uniform processing can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment in which the present invention is applied to a vertical heat treatment apparatus, and FIG. 2 is a schematic explanatory view showing, in an enlarged manner, a branch pipe provided in the exhaust pipe of FIG. 10 Process pipe 12 Gas introduction pipe 14 Lid 16 Heater 17 Boat 18 Wafer 19 Mounting table 20 Exhaust fan 22 Exhaust pipe 23 Common exhaust pipe 30 …… Mass flow controller 40 …… Branch pipe 42 …… Movable valve 44 …… O-ring 46 …… Recess 48 …… Piping

Claims (3)

(57) [Claims] In a processing apparatus having a mechanism for exhausting gas through an exhaust pipe, a tributary pipe is provided in the middle of the exhaust pipe, and the tributary pipe is opened and closed by a pressure difference with the atmosphere, and the inside of the exhaust pipe is predetermined. A processing apparatus, comprising a movable valve for allowing atmospheric air to flow so as to maintain the pressure. 2. An end of the tributary pipe is opened downward to the atmosphere, and the movable valve is closed by its own weight in a huge concave portion provided at the end, and is opened by a pressure difference from the atmosphere. The processing apparatus according to claim 1, wherein the processing apparatus is provided in a processing unit. 3. A heat treatment apparatus having a mechanism for exhausting gas through an exhaust pipe, wherein a tributary pipe is provided in the middle of the exhaust pipe, and the tributary pipe is opened and closed by a pressure difference from the atmosphere, and the inside of the exhaust pipe is predetermined. A heat treatment apparatus comprising a movable valve for allowing air to flow so as to maintain the pressure.