JPH11111705A - Semiconductor manufacturing equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] By forcibly liquefying exhaust gas at a specific portion of an exhaust pipe, it is possible to specify a liquefied portion, facilitate liquefaction removal during maintenance, and reduce equipment downtime. . SOLUTION: An exhaust pipe 10 connected to a reaction chamber 1 is
From the upstream side to the downstream side, the heated exhaust pipe section 50, the cooling trap section 51, the non-heated exhaust pipe section 52, the pump 3,
It is composed of an atmospheric pressure exhaust pipe section 4. In the heating exhaust pipe section 50, the exhaust gas is heated so as not to be liquefied. In the cooling trap unit 51, the gas is heated so as to be liquefied, and liquefaction occurs only in the cooling trap unit 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to an exhaust gas for effectively removing a raw material liquefied in an exhaust pipe when a raw material which becomes liquid at normal temperature and normal pressure is used as a process gas. The present invention relates to an apparatus having a system.

[0002]

2. Description of the Related Art As shown in FIG. 5, for example, a conventional semiconductor manufacturing apparatus includes a reaction chamber 1 for reacting a process gas to form a film on a wafer, and a liquid material for supplying the process gas to the reaction chamber 1. 6, a supply pipe 5 connecting the vaporizer 6 and the reaction chamber 1 and supplying a process gas to the reaction chamber 1, a pump 3 for depressurizing the reaction chamber 1 and creating a flow of the process gas, An exhaust pipe section 2 connecting the reaction chamber 1 and the pump 3, an atmospheric pressure exhaust pipe section 4 after the pump 3, and a wafer transfer section 7 for transferring a wafer into the reaction chamber 1.

[0003] In the reaction chamber 1 of this semiconductor manufacturing apparatus, a film is formed on a wafer. At the same time, a film adheres to the inside of the reaction chamber 1 and the film accumulates as the number of film formation processes increases. If the film thickness exceeds a certain amount, particles are generated. Therefore, a cleaning ClF ₃ gas is flown to etch the accumulated film adhered in the reaction chamber.

[0004]

However, the above-described conventional semiconductor manufacturing apparatus has the following problems.

(1) When a raw material which is liquefied at normal temperature and normal pressure is used as a process gas, the gas is liquefied in one of the exhaust systems after the pump 3 which becomes normal pressure. When liquefied, depending on the liquefied raw material, for example, Ta (OC ₂ H ₅ )
An exothermic reaction may occur with ClF ₃ for cleaning. When an exothermic reaction occurs, damage occurs in some places that generate heat. For example, the O-ring sealing the seam of the pipe may be damaged, or the pump may be damaged. Therefore, when cleaning the accumulated film on the inner wall of the reaction chamber 1 with ClF ₃ , it is necessary to remove the liquefied gas in advance, but liquefaction may occur in the exhaust pipe 2 upstream of the pump 3. Yes, it is not possible to identify the liquefied part of the exhaust pipe.Therefore, it is necessary to disassemble all the pipes and maintain the pipes individually, which makes maintenance work difficult. Occurs.

(2) Usually, when performing maintenance of piping,
Since the exhaust pipe is disassembled to open the exhaust pipe to the atmosphere, it is inevitable that moisture in the atmosphere adheres to the inner wall of the pipe. When a pipe is assembled with moisture adhered to the inner wall of the pipe and a ClF ₃ gas for cleaning is supplied, the ClF ₃ gas reacts with the moisture, and the reaction causes pipe corrosion.

(3) In order to prevent the reaction with atmospheric moisture described in (2) above, purging with a non-reactive gas or an inert gas may be performed for several hours after the piping is assembled.
Then, the downtime of the entire apparatus becomes longer.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art by forcibly liquefying exhaust gas at a specific portion of an exhaust pipe. It is an object of the present invention to provide a semiconductor manufacturing apparatus capable of preventing pipe corrosion due to a reaction between atmospheric moisture and ClF ₃ and reducing downtime of the apparatus.

[0009]

According to the first aspect of the present invention, a raw material that becomes a liquid at normal temperature and normal pressure is gasified, a film is formed in a reaction chamber, and the processed gas is exhausted from an exhaust pipe. In the semiconductor device, from the upstream side to the downstream side of the exhaust pipe, a gasification region for applying a temperature or pressure at which the gas does not become a liquid and a liquefaction region for applying a temperature or pressure at which the gas becomes a liquid are formed, Liquefaction occurs intensively in the liquefaction area. Since the exhaust pipe is divided into a gasification area for maintaining a gas state and a liquefaction area for liquefying gas, it is possible to specify a liquefied portion in the exhaust pipe.

According to a second aspect of the present invention, there is provided a supply pipe for supplying a gas generated by vaporizing a raw material which becomes liquid at normal temperature and normal pressure to a reaction chamber, and reacting the supplied gas to form a film. A reaction chamber to be performed, an exhaust driving source for depressurizing the reaction chamber to create a flow of the gas, and an exhaust driving source that is provided between the reaction chamber and the exhaust driving source to exhaust the gas exhausted from the reaction chamber. A heating / exhaust pipe section for heating to a temperature that does not become a liquid; and a cooling trap section for cooling a heating gas from the heating / exhaust pipe section to a temperature at which the liquid becomes a liquid and capturing the raw material that has become a liquid. It is.

A raw material which becomes liquid at normal temperature and normal pressure is vaporized to be a gas, and is supplied to a reaction chamber via a supply pipe to contribute to film formation. The remaining gas that has not contributed to the film formation is exhausted from the reaction chamber via the heating exhaust pipe. Since the gas is heated in the heated exhaust pipe section, the gas state is maintained. The gas flows from the heating exhaust pipe section to the cooling trap section, where it is cooled and becomes a liquid and is captured. The gas that did not become liquid is sucked up by the exhaust driving source.

As described above, when the gas is cooled to a liquid temperature in the cooling trap portion and the raw material in the liquid state is captured, the gas in the exhaust piping including the heating / exhaust piping portion, the cooling trap portion, the exhaust driving source, etc. Since the liquefied portion is specified by the cooling trap portion, the liquid material can be easily removed only by maintaining the cooling trap portion. Therefore, when cleaning the accumulated film adhered to the reaction chamber using the ClF ₃ gas, only the maintenance of only the cooling trap portion of the exhaust pipe is performed in advance to avoid the reaction of the liquid raw material with the ClF ₃ gas. Thus, it is possible to effectively prevent the exhaust pipe and the exhaust drive source from being damaged by the exothermic reaction.

Further, since only the cooling trap portion of the exhaust pipe needs to be maintained, as in the case where the entire exhaust pipe is maintained, the atmospheric moisture and ClF ₃ gas adhering to the exhaust pipe during maintenance are required. This eliminates the risk of corrosion of the exhaust pipe due to the reaction, and eliminates the need to purge the exhaust pipe with an inert gas for a long time to avoid the corrosion.

According to a third aspect of the present invention, in the second aspect of the present invention, the cooling trap portion includes a drain pipe provided on a surface for capturing a liquid and an on-off valve provided in the middle of the drain pipe. It is provided. ClF _{3 for} exhaust pipe
When the gas does not flow, the liquid trapped in the cooling trap is discharged from the cooling trap by opening an on-off valve provided in the drain pipe. When flowing ClF ₃ gas through the exhaust pipe,
Close the on-off valve to prevent the ClF ₃ gas from coming into contact with the liquid. Since the liquid is discharged from the drain pipe to the outside of the cooling trap section, there is no need to maintain the cooling trap section, so that downtime of the apparatus is eliminated.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the surface of the cooling trap portion for capturing the liquid is inclined so that the liquid flows into the drain pipe. Since the surface of the cooling trap section for capturing the liquid is inclined, the liquid captured on the surface flows into the drain pipe from the surface. Therefore, the recovery of the liquid is ensured, and the contact with the gas can be further avoided.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the raw material which becomes a liquid at normal temperature and normal pressure contains Ta.
(OC ₂ H ₅ ) ₅ is used. Raw material is Ta
When (OC ₂ H ₅ ) ₅ is liquefied, ClF
_This is particularly useful because an exothermic reaction is more likely to occur with ₃ .

[0017]

Embodiments of the present invention will be described below.

The semiconductor manufacturing apparatus of the embodiment shown in FIG.
A reaction chamber 1 for reacting a process gas to form a film on a wafer, a vaporizer 6 for vaporizing a liquid raw material for supplying a process gas to the reaction chamber 1, and a reaction between the vaporizer 6 and the reaction chamber 1. A supply pipe for supplying a process gas to the chamber; A wafer is transferred from the wafer transfer unit 7 into the reaction chamber 1.

A pump 3 as an exhaust driving source for depressurizing the reaction chamber 1 to generate a flow of process gas and the reaction chamber 1
A heated exhaust pipe section 50 as a vaporizing region for heating exhaust gas exhausted from the reaction chamber 1 from the upstream side to the downstream side to a temperature at which the exhaust gas is not liquefied;
The apparatus includes a cooling trap section 51 connected to the heated exhaust pipe section 50 as a liquefaction region for cooling the gas to a liquid temperature and capturing the liquid, and a non-heated exhaust pipe section 52 which does not necessarily need to be heated.

The pump 3 and the subsequent parts are provided with an atmospheric pressure exhaust pipe 4 whose pressure becomes atmospheric pressure.

As a method for heating the heating / exhaust pipe section 50, any of a resistance heating method, a high-frequency induction heating method, an infrared intensive heating method and the like may be adopted. When Ta (OC ₂ H ₅ ) ₅ is used as a process gas,
For example, it is heated to 150 ° C. At this temperature, Ta (OC ₂
H _{5) 5} gas does not liquefy.

As shown in FIG. 2, for example, the cooling trap section 51 includes a trap exhaust pipe section 61, a refrigerant jacket 63 provided therearound, a refrigerant supply pipe 60 for flowing refrigerant into the refrigerant jacket 63, and a jacket 63. And a refrigerant discharge pipe 62 that allows the refrigerant to flow out of the trap exhaust pipe section 61. By flowing the refrigerant around the trap exhaust pipe section 61, the gas flowing through the trap exhaust pipe section 61 is cooled to a temperature at which it is constantly liquefied. The liquefied raw material adheres or accumulates on 61 and is captured. Ta (OC ₂ H ₅ ) ₅ as process gas
When Ta is used, for example, at this temperature of cooling to 25 ° C. using cooling water, the Ta (OC ₂ H ₅ ) ₅ gas always liquefies.

More specifically, it is preferable that the cooling trap section 51 is configured as follows. The surface of the trap exhaust pipe portion 61 where liquid material is expected to adhere or accumulate, for example, the bottom surface 71 is inclined with respect to the horizontal plane so that the center of the bottom surface is lowest, and is formed in a mortar shape. Are all gathered in the center of the bottom. A drain pipe 72 for discharging the liquid flowing along the inclined surface 71 from the trap exhaust pipe section 61 to the outside is connected to the bottom center. A drain box 74 for collecting the discharged liquid is connected to the drain pipe 72. An on-off valve 73 is provided in the middle of the drain pipe 72 so that the trap exhaust pipe section 61 and the drain box 74 can be shut off. With this configuration, the liquid can be reliably recovered, and the contact between the cleaning gas and the recovered liquid can be reliably cut off.

FIG. 3 shows a case where one drain box 74 is provided in the trap exhaust pipe section 61, and FIG.
As shown in FIG.
4 may be provided to polymerize the cooling trap section. That is, the straight trap exhaust pipe portion 61 is bent only at several places (two places in the illustrated example) upward to meander, and the meandering start part 61a, the folded part 61b which is the lowest in the meandering part, and the inclination of the meandering end part 61c. A drain pipe 72 is connected to each of the three places where the surface 70 ends so that the liquid can be recovered in a stepwise manner. Since the liquid is recovered in a stepwise manner as described above, there is no leakage in the recovery, and the liquid recovery is further ensured.

The polymerization of the cooling trap is not limited to the above. The cooling trap section having the structure shown in FIG. 3 may be connected in multiple stages, or the trap exhaust pipe section may be bent vertically in FIG. 4 to meander.

In the exhaust system as described above, during the film formation, the heating / exhaust piping section 50 is heated to a temperature at which the gas does not liquefy, and the cooling trap section 51 is cooled to a temperature at which the gas liquefies. As the film formation on the wafer is repeated in the reaction chamber 1 in this manner, the film adheres also in the reaction chamber 1 and the film accumulates as the number of film formation processes increases. . Therefore, a cleaning gas is flowed into the reaction chamber 1 to etch away the accumulated film adhered in the reaction chamber 1. In advance, the exhaust pipe 10 is maintained in order to remove the liquid accumulated in the exhaust pipe 10.
At this time, as shown in FIG. 2, the cooling trap unit 51 is cooled and liquefaction is caused intensively in the cooling trap unit 51. Maintenance is easier than in the case of maintenance.

In particular, when a raw material which is liable to generate an exothermic reaction with the cleaning ClF ₃ gas, for example, Ta (OC ₂ H ₅ ) is used as a process gas at the time of film formation, the exhaust piping 10
3 or FIG. 4 may be used as the cooling trap part 51 constituting a part of the above. When the ClF ₃ gas is not allowed to flow through the exhaust pipe 10, the on-off valve 73 provided on the drain pipe 72 is opened, and the raw material liquefied and captured by the cooling trap unit 51 is guided to the drain pipe 72 along the inclined bottom surface, and the drain box is drained. Collect in 74. When the ClF ₃ gas flows into the exhaust pipe 10 for cleaning, the on-off valve 73 is closed so that the ClF ₃ gas does not contact the liquid collected in the drain box 74 through the drain pipe 72.

As described above, in the embodiment, since the heating / exhaust pipe section 50 is heated to a temperature at which it does not liquefy, the heating / exhaust pipe section 50 does not liquefy. In addition, the cooling trap 51
Cools the trap exhaust pipe section 61 to the temperature at which it liquefies, so that liquefaction occurs intensively here, and the subsequent unheated exhaust pipe section 52, pump 3, and atmospheric pressure exhaust pipe section 4
Does not cause liquefaction. Therefore, in order to remove the liquid in the exhaust pipe 10, the cooling trap 51
Only the maintenance needs to be performed intensively.

During film formation, the on-off valve 73 is opened to collect the liquid in the drain box 74.
Closing the on-off valve 73 before flowing the 1F ₃ gas can prevent ClF ₃ from flowing into the drain box 74. Further, since all the liquid is collected in the drain box 74, no liquid remains in the trap exhaust pipe section 61, so that there is no need to perform maintenance of the trap exhaust pipe section 61, and downtime of the apparatus is eliminated. Also, the removal of the liquid from the drain box 74
It is not always necessary to perform the cleaning before the cleaning, but can be performed at any time, and may be performed during the cleaning.

The present invention can be applied to all semiconductor manufacturing apparatuses irrespective of a vertical furnace or a single-wafer furnace. Further, in the embodiment, the phase change of the film forming raw material is realized by using the temperature as a parameter, but may be realized by the pressure. The target substrate on which the film is formed is not limited to a wafer, but may be a glass substrate for a liquid crystal display.

[0031]

According to the present invention, since the exhaust pipe is divided into a gasification area and a liquefaction area so that the liquefied portion can be specified, maintenance of the exhaust pipe for removing the liquid becomes easy.

Further, since the cooling trap section is cooled and liquefaction occurs intensively in the cooling trap section, the maintenance of the cooling trap section can be performed intensively, which is compared with the case where all the exhaust pipes are maintained. Maintenance becomes easy.

When all the exhaust pipes are maintained, moisture in the atmosphere tends to adhere to the exhaust pipes, but the reaction between the moisture and ClF ₃ does not corrode the exhaust pipes.

Further, since the liquid is trapped in the cooling trap section, maintenance of the exhaust pipe is facilitated, downtime of the apparatus can be reduced, and the production of semiconductors can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an entire semiconductor manufacturing apparatus according to an embodiment.

FIG. 2 is a principle diagram of a cooling trap unit according to the embodiment.

FIG. 3 is a basic configuration diagram of a cooling trap unit corresponding to a liquefied gas that causes an exothermic reaction with ClF ₃ according to the embodiment.

FIG. 4 is a configuration diagram showing another embodiment in which the cooling trap portion is polymerized.

FIG. 5 is a schematic configuration diagram of a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction chamber 3 Pump (exhaust drive source) 10 Exhaust pipe 50 Heated exhaust pipe part (vaporization area) 51 Cooling trap part (liquefaction area) 52 Non-heated exhaust pipe part

Claims (5)

[Claims] 1. A semiconductor device for gasifying a raw material which becomes a liquid at normal temperature and normal pressure, performing a film forming process in a reaction chamber, and exhausting the processed gas from an exhaust pipe, wherein the exhaust pipe has an upstream side to a downstream side. Applying a temperature or pressure at which said gas does not become liquid; and
A semiconductor manufacturing apparatus in which a liquefaction region for applying a temperature or pressure at which gas becomes a liquid is formed, and liquefaction occurs intensively in the liquefaction region. 2. A supply pipe for supplying a gas generated by evaporating a raw material which becomes a liquid at normal temperature and normal pressure to a reaction chamber; a reaction chamber for reacting the supplied gas to form a film; An exhaust drive source for reducing the pressure of the chamber to create a flow of the gas, and being provided between the reaction chamber and the exhaust drive source, heating the gas exhausted from the reaction chamber to a temperature at which the gas does not become liquid. A semiconductor manufacturing apparatus, comprising: a heating / exhaust pipe section to be heated; and a cooling trap section that cools a heating gas from the heating / exhaust pipe section to a liquid temperature and captures the liquid material. 3. The semiconductor manufacturing apparatus according to claim 2, wherein the cooling trap section includes a drain pipe provided on a surface for capturing a liquid, and an on-off valve provided in the middle of the drain pipe. 4. The semiconductor manufacturing apparatus according to claim 3, wherein a surface of the cooling trap section for capturing the liquid is inclined so that the liquid flows into the drain pipe. 5. The raw material which becomes liquid at normal temperature and normal pressure is Ta.
_5. The semiconductor manufacturing apparatus according to claim 1, wherein (OC ₂ H ₅ ) ₅ .