JPH06177054A - Method and device for replacing gas in main chamber in vertical semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To maintain a high atmosphere shielded state by delivering excess inert gas while continuously replenishing a small amount of inert gas by reducing the amount of supply of inert gas and then forcibly circulating the inert gas with operation of a blower after the remaining oxygen concentration reaches a specific value by supplying inert gas. CONSTITUTION:A nitrogen gas forced circulation path 7 is closed and at the same time a switching valve 12 of a first nitrogen gas delivery path 13 is closed. thus operating a blower 8 while supplying a large amount of pure nitrogen gas from a pure nitrogen gas supply path 11. Then, a large amount of pure nitrogen gas flows into a main chamber A via the forced circulation path 7. Then, it is diffused into internal air and is mixed with it and at the same time the mixed gas circulates the forced circulation path 7 and an excess mixed gas is delivered to the outside via a second nitrogen gas delivery path 14 on the way. When a large amount of pure nitrogen gas continues to be supplied from the pure nitrogen gas supply path 11 for a specific amount of time, the concentration of the nitrogen gas in the main chamber A increases rapidly, thus resulting in a state without any oxygen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical semiconductor manufacturing apparatus, in which an inert gas and air in a main chamber accommodating various devices for chemically processing a wafer are mutually replaced, and It relates to the device.

[0002]

2. Description of the Related Art In a vertical semiconductor manufacturing apparatus, a large number of wafers stored horizontally in a storage rack of a wafer carrier are transferred by a transfer robot to a wafer holder called a wafer boat in multiple stages. Then, it is a device for performing chemical treatment (chemical vapor deposition) in the heater (reaction vessel). In this semiconductor manufacturing apparatus, in order to prevent the oxidation of the wafer at a high temperature during the chemical treatment and the oxidation of the wafer at a normal temperature during the transfer and transfer of the wafer, the above-mentioned treatment in an atmosphere isolated from the atmosphere, and Some operations are performed. In the main chamber of this semiconductor manufacturing apparatus, an elevating device for loading and unloading the wafer boat into and from the heater on the ceiling, a carrier stage for storing a wafer carrier containing a large number of wafers, and each wafer in the wafer carrier. Various devices such as a transfer robot for transferring the wafers to the wafer boat are housed and arranged. Further, inside and outside tubes are arranged inside the heater, and a wafer boat on which a large number of wafers are placed enters into the inside tube to perform the chemical treatment of the wafers.

As a means for shutting off the main chamber from the atmosphere,
It is known to use an inert gas. In this main room, it is necessary for an operator to enter inside and perform periodic maintenance and inspection. For example, it is a case of removing the chemical product attached to the inner tube described above during the chemical treatment. The inert gas atmosphere itself that shuts off the main room is extremely dangerous for humans because oxygen hardly exists, so when performing maintenance inspection work, It is necessary to discharge all the inert gas.

[0004]

SUMMARY OF THE INVENTION The present invention makes it possible to easily replace the inert gas in the main chamber with the air when shutting off the atmosphere in the main chamber of the vertical semiconductor manufacturing apparatus by the inert gas, and thus the high atmospheric pressure can be achieved. An object of the invention is to make it possible to maintain the shutoff state, and at the same time, to discharge all of the inert gas inside during maintenance and inspection work in the main chamber.

[0005]

Means adopted by the present invention for solving this problem include various devices such as a wafer boat, a lifting device for the wafer boat, a wafer storage device, and a wafer transfer robot. When the inert gas and the air in the main chamber of the vertical semiconductor manufacturing apparatus are mutually replaced, the inside portion of one side plate of the main chamber is used as an inflow portion, and the inside portion of the other side plate opposite to the side plate is provided. As an outflow portion, an inert gas forced circulation path is formed between the inflow portion and the outflow portion, and when the inert gas is replaced, the inert gas is supplied and the residual oxygen concentration reaches a predetermined value. While reducing the supply amount of inert gas and continuously supplying a small amount of inert gas, the inert gas is forcibly circulated by the action of the blower and the excess inert gas is discharged to shut off the atmosphere in the main chamber. Maintain
At the time of air exchange, the supply of the inert gas is stopped, a large amount of air is caused to flow into the main chamber by the action of the blower, and the inert gas in the main chamber is discharged.

[0006]

EXAMPLES The present invention will be described in more detail below with reference to examples. FIG. 1 is a schematic side sectional view showing an arrangement of each chamber of a vertical semiconductor manufacturing apparatus, in which a load lock chamber B is provided between a main chamber A and the outside of the device, and the main chamber A and the load lock chamber B are provided. A device storage chamber C is provided above the. In the main chamber A, a wafer boat (not shown) accommodating wafers
An elevating device 2 for putting the heater in and out of the heater 1 on the ceiling,
A carrier stage for mounting a wafer carrier containing a large number of wafers, a transfer robot (not shown) for transferring each wafer in the wafer carrier to the wafer boat, and the like are arranged. There is. Main room A
The inside of the container is shielded from the atmosphere by the method of the present invention. The load lock chamber B is a chamber for loading and unloading a wafer carrier containing a large number of wafers between the main chamber A and the outside of the apparatus, and like the main chamber A, the atmosphere is shut off by nitrogen gas. There is. Doors 3a and 3b are provided between the load lock chamber B, the main chamber A, and the outside of the apparatus so as to be able to open and close, respectively.

The inside of the main chamber A is shut off from the atmosphere by nitrogen gas by the method of the present invention. FIG. 2 is a cross-sectional view taken along line XX of FIG. 1, and as is clear from this figure, the heater 1 and the lifting device 2 thereof are each provided with one side plate 4
It is provided close to a and has little space, but there is some space in the part close to the other side plate 4b. A door 3a is provided between the main chamber A and the load lock chamber B, and since the wafer carrier moves in and out, various devices cannot be installed in this portion.
Therefore, as shown in FIG. 2, by arranging the filter 5 inside the side plate 4b, which has some space,
This part is used as an inlet for nitrogen gas, and the side plate 4
A portion inside the side plate 4a facing b is used as an outflow portion of nitrogen gas, and the inflow portion and the outflow portion are connected by a duct 6 to form a nitrogen gas forced circulation path 7. A blower 8 is provided in the middle of the duct 6, and the blower 8 forcedly circulates the nitrogen gas filled in the main chamber A. Both the duct 6 and the blower 8 are installed in the equipment storage chamber C.

The blowing side of the blower 8 in the nitrogen gas forced circulation path 7 is provided with a pure nitrogen gas source (not shown) via an opening / closing valve 9.
To form a pure nitrogen gas supply path 11. Further, the suction side of the blower 8 in the forced circulation path 7 communicates with the atmosphere through the open / close valve 12, and the first nitrogen gas discharge path 1
A second nitrogen gas discharge passage 14 is provided on the suction side of the blower 8 in the forced circulation passage 7 for discharging nitrogen gas little by little when the air is shut off. The nitrogen gas discharge passage 14 is located on the atmosphere side with respect to the on-off valve 12, and the first nitrogen gas discharge passage 13 is provided.
It is connected to the. Further, between the blower 8 and the first nitrogen gas discharge passage 13 in the forced circulation passage 7, an air supply passage 15 for taking in external air into the main chamber A is connected via a three-way switching valve 16. There is.

Next, a method of shutting off the atmosphere in the main chamber A with nitrogen gas will be described. First, as shown in FIG. 2, the nitrogen gas forced circulation path 7 is closed, the on-off valve 12 of the first nitrogen gas discharge path 13 is closed, and a large amount of pure nitrogen gas is supplied from the pure nitrogen gas supply path 11. However, when the blower 8 is operated, a large amount of pure nitrogen gas flows into the main chamber A through the forced circulation path 7, diffuses into the internal air and is mixed, and at the same time, the mixed gas is forced into the forced circulation path. While cycling through 7,
In the middle of the process, the surplus mixed gas is discharged to the outside through the second nitrogen gas discharge passage 14. Pure nitrogen gas supply path 11
When a large amount of pure nitrogen gas is continuously supplied for a predetermined time, the nitrogen gas concentration in the main chamber A rapidly increases, and after a predetermined time elapses, the main chamber A is filled with nitrogen gas and becomes substantially oxygen-free. . And the oxygen concentration in the main chamber A is 10 ppm
If the amount of pure nitrogen gas is reduced to a certain level and the nitrogen gas in the main chamber A continues to be forcedly circulated through the forced circulation path 7, the pressure of the nitrogen gas in the main chamber A becomes higher than the atmospheric pressure. Since the amount of nitrogen gas is slightly higher, the amount of nitrogen gas corresponding to the supply amount of pure nitrogen gas is discharged from the second nitrogen gas discharge passage 14, and the nitrogen gas concentration in the main chamber A is maintained without decreasing. Then, the atmosphere in the main chamber A is shut off by the nitrogen gas. Here, various devices are arranged in the main chamber A as described above, and the nitrogen gas flowing into the main chamber A is in a state where it is difficult for the nitrogen gas to naturally diffuse. Forced circulation of the gas promotes its diffusion. Further, since the nitrogen gas is forcedly circulated, the dusts in the main chamber A and the duct 6 are also included in the nitrogen gas and circulate, but the dust is effective due to the filter 5 provided at the inflow portion. Will be removed. Main room A
An oxygen concentration meter is provided inside, and when the oxygen concentration in the main chamber A reaches a set value by this, the flow control valve provided in the pure nitrogen gas supply passage 11 is actuated to operate the pure nitrogen gas The supply amount is automatically reduced.

When performing maintenance and inspection work in the main chamber A, as shown in FIG. 3, first, the supply of pure nitrogen gas is stopped, and the air supply passage 15 is opened by operating the three-way switching valve 16. The nitrogen gas forced circulation path 7 is cut off and the opening / closing valve 12 of the first nitrogen gas discharge path 13 is opened. As a result, a large amount of air outside the apparatus flows into the main chamber A through the air supply passage 15 by the suction action of the blower 8, and the nitrogen gas in the main chamber A passes through the first nitrogen gas discharge passage 13. Are transported to a safe place outside the equipment and discharged. After a lapse of a predetermined time, all the nitrogen gas in the main chamber A is discharged to the outside of the apparatus, and the worker enters the main chamber A. When the blower 8 is rotated at a high speed to increase the air inflow rate per hour, the nitrogen gas in the main chamber A can be discharged in a short time.

In the above embodiment, the pure nitrogen gas supply path 11 is connected to the blower side of the blower 8, but this pure nitrogen gas supply path 11 is along the direction in which the nitrogen gas flows in the forced circulation path 7. It is also possible to connect to the suction side of the blower 8 in a range that is not upstream of the first nitrogen gas discharge passage 13. Further, in the above-described embodiment, the relatively inexpensive pure nitrogen gas is used as the inert gas, but the present invention is not limited to this, and argon or the like can be used.

[0012]

According to the present invention, the inside portion of one side plate of the main chamber serves as the inflow portion, and the inside portion of the other side plate facing the side plate serves as the outflow portion, and the space between the inflow portion and the outflow portion is set. When a forced circulation path of inert gas is formed in and the inert gas is replaced, after supplying the inert gas and the residual oxygen concentration reaches a predetermined value, the supply amount of the inert gas is reduced to reduce the amount of the inert gas. While continuously replenishing the air, the inactive gas is forcibly circulated by the action of the blower and excess surplus of the inert gas is discharged to maintain the air cutoff state in the main chamber. Then, since a large amount of air is caused to flow into the main chamber by the action of the blower and the inert gas in the main chamber is discharged, the diffusion of the inert gas in the main chamber in which various devices are arranged is prevented. Promoted and high air interception in all its parts State with the can maintain, can be discharged in a short time within the main chamber of the inert gas.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing an arrangement of chambers of a vertical semiconductor manufacturing apparatus.

2 is a sectional view taken along line XX of FIG. 1 in a state where nitrogen gas in the main chamber A is forcedly circulated.

3 is a cross-sectional view taken along line XX of FIG. 1 in a state where nitrogen gas in the main chamber A is being discharged.

[Explanation of symbols]

 A: Main chamber 4a, 4b: Side plate of vertical semiconductor manufacturing equipment 6: Duct 7: Nitrogen gas forced circulation path 8: Blower 11: Pure nitrogen gas supply path 13: First nitrogen gas discharge path 14: Second nitrogen gas discharge Line 15: Air supply line 16: 3-way switching valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Yamashita 150 Motoyashiki, Miyaya-cho, Toyohashi City, Aichi Shinko Electric Co., Ltd. Toyohashi Factory

Claims (2)

[Claims] 1. An inert gas and air in a main chamber of a vertical semiconductor manufacturing apparatus in which various devices such as a wafer boat, a lifting device for the wafer boat, a wafer storage device, and a wafer transfer robot are housed. In the method, the inner part of one side plate of the main chamber is used as an inflow part, and the inner part of the other side plate facing the side plate is used as an outflow part, and between the inflow part and the outflow part. When an inert gas forced circulation path is formed and the inert gas is replaced, after supplying the inert gas and the residual oxygen concentration reaches a predetermined value, the supply amount of the inert gas is reduced to remove a small amount of the inert gas. While continuously replenishing, the inert gas is forcibly circulated by the action of the blower to discharge the surplus inert gas to maintain the air shutoff state in the main chamber, and when the air is replaced, the replenishment of the inert gas is stopped. A large amount of air due to the action of the blower. A method for gas replacement in a main chamber of a vertical semiconductor manufacturing apparatus, characterized in that the inert gas in the main chamber is discharged by inflowing into the chamber. 2. An inert gas and air in a main chamber of a vertical semiconductor manufacturing apparatus in which various devices such as a wafer boat, a lifting device for the wafer boat, a wafer storage device, and a wafer transfer robot are housed. A device for replacing the inside of one side plate of the main chamber as an inflow part, and the inside part of the other side plate facing the side plate as an outflow part, and between the inflow part and the outflow part. An inert gas for supplying an inert gas into the main chamber at a proper place of the forced circulation path by forming a forced circulation path of the inert gas by connecting with a duct and a blower and providing a filter at the inflow part. By connecting the supply passage, the inert gas discharge passage for discharging the inert gas in the main chamber, and the air supply passage for taking in external air into the main chamber, the inert gas and the air in the main chamber Specially configured to switch the supply The gas replacement device in the main chamber of the vertical semiconductor manufacturing equipment.