JPH07161643A - Vacuum treater - Google Patents

Abstract

PURPOSE:To reduce significantly the amount of infiltration of water vapor into an exhaust chamber at the time when a material to be treated is inserted in the exhaust chamber and to make it possible to shorten an exhaust time. CONSTITUTION:Dry air is introduced in an exhaust chamber 3 through a dry air introducing tube 13 before the opening of an entrance door 6 and this introduction is continued during the time ranging from the opening of the door 6 to the shutting of the door 6. When a pressure in the chamber 3 becomes equal to the atmosphere by this introduction of the dry air, the door 6 is opened, a material to be treated is inserted in the chamber 3. At this time, the dry air, which is exhausted from the chamber 3 to the outside, reduces the amount of infiltration of the atmosphere into the chamber 3. After the door 6 is shut, the introduction of the dry air into the chamber 3 is stopped and at the same time, the dry air is sprayed on vacuum sealing materials 8 via grooves 10 through a dry air tube 11. This spray is continued until the pressure in the chamber 3 is made lower than the atmosphere by evacuation using an exhaust valve 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum processing apparatus, and more particularly, to a vacuum processing apparatus in which an exhaust chamber and a vacuum processing chamber are adjacent to each other through an isolation valve, and an object to be processed is inserted from the exhaust chamber side into the vacuum processing chamber. Regarding

[0002]

2. Description of the Related Art Vacuum processing apparatuses are widely used in various fields including semiconductor manufacturing apparatuses such as dry etching apparatuses, sputtering apparatuses and CVD apparatuses. In such a vacuum processing apparatus, when the object to be processed is inserted into the vacuum processing chamber by opening the entrance door of the vacuum processing chamber, the atmosphere is mixed into the vacuum processing chamber.
Since nitrogen and oxygen in the atmosphere have a high vapor pressure, they do not significantly affect the exhaust of the vacuum processing chamber. However, the vapor pressure of water vapor in the atmosphere is as low as about 3000 Pa, and it is adsorbed inside the vacuum processing chamber and gradually released into the vacuum exhaust.
It takes a long time to remove it. In particular, it may take several hours to several tens of hours for evacuation because there are many electrodes for processing and organic substances having high hygroscopicity inside the vacuum processing chamber.

Therefore, as a vacuum processing apparatus for industrial production, which requires high production efficiency in order to reduce the exhaust time, a vacuum processing apparatus having a structure in which an exhaust chamber is connected to a vacuum processing chamber via an isolation valve is used. Commonly used. In this type of vacuum processing apparatus, first open the inlet door of the exhaust chamber, insert the object to be processed into it, exhaust the exhaust chamber to a specified pressure after closing the inlet door, and then open the isolation valve. Insert the object to be processed into the vacuum processing chamber. In this case, the atmosphere enters the exhaust chamber when the object to be treated is inserted.Therefore, in order to minimize the amount of atmospheric invasion into the exhaust chamber, nitrogen gas that does not contain water vapor, etc. should be opened before opening the inlet door. Is introduced into the exhaust chamber to pre-pressurize the exhaust chamber. By providing such an exhaust chamber, the exhaust time can be shortened from several minutes to several tens of minutes.

Recently, in order to improve the productivity of the vacuum processing apparatus, it is required to further reduce the exhaust time. For example, in a vacuum processing apparatus for sputtering film formation that mass-produces magneto-optical disks and the like, it is required to reduce the exhaust time to several seconds to several tens of seconds. Therefore, various means such as increasing the capacity of the exhaust pump, reducing the size of the exhaust chamber to reduce the adsorption surface area of water vapor, and heating the exhaust chamber to reduce the adsorption amount of water vapor have been taken. .

[0005]

However, since none of the conventional vacuum processing apparatuses prevent or reduce the invasion of water vapor in the atmosphere, the problem inherent to the adsorption of water vapor in the exhaust chamber is essential. Couldn't be solved.

Specifically, since the re-emission of the water vapor adsorbed on the surface of the exhaust chamber simply decreases depending on the exhaust time,
Even if the large-capacity exhaust pump described above is used, the amount of water vapor released from the surface of the exhaust chamber does not change, and therefore, there is a problem that this water vapor adversely affects the vacuum processing. For example, in the sputtering film forming method, there is a problem that the quality of the thin film deteriorates due to the interaction between the released water vapor and the deposited film.

Further, the size reduction and heating of the exhaust chamber do not reduce the invasion of water vapor itself when the object to be treated is inserted. Further, there is a problem that miniaturization of the exhaust chamber is limited by the size of the object to be processed, and heating is limited by the heat resistant temperature of the object.

Therefore, an object of the present invention is to provide a vacuum processing apparatus capable of significantly reducing the amount of water vapor entering the exhaust chamber when inserting the object to be processed into the exhaust chamber and shortening the exhaust time. Especially.

[0009]

To achieve this object, the present invention provides an exhaust chamber having an inlet door and a vacuum sealing material for sealing the inlet door, and an exhaust means for exhausting the exhaust chamber to vacuum. In a vacuum processing apparatus comprising a vacuum processing chamber that is connected to the exhaust chamber via an isolation valve and vacuum-processes an object to be processed inserted from the exhaust chamber, during opening to closing of the inlet door, A dry air introduction mechanism for introducing dry air into the exhaust chamber, and a dry air is blown around the vacuum seal material from the atmosphere side with the vacuum seal material sandwiched between the dry air introduction mechanism and the exhaust chamber. With a dry air blowing mechanism that continues until the pressure becomes lower than the atmospheric pressure.

In such a structure, the dry air introducing mechanism introduces the dry air into the exhaust chamber until the pressure in the exhaust chamber becomes substantially equal to the atmospheric pressure before opening the inlet door. However, it is desirable to stop the introduction of the dry air after closing the inlet door. Pressurization of the exhaust chamber using conventionally used nitrogen gas, etc., stops the supply of nitrogen gas together with the opening of the inlet door, and it is essentially impossible to prevent the mixing of outside air. Absent.

[0011]

The object to be processed is inserted into the exhaust chamber through the open entrance door. When this inlet door is closed, the exhaust chamber is sealed with a vacuum sealing material and exhaust is performed.

The dry air introducing mechanism introduces dry air into the exhaust chamber during the period from the opening of the inlet door to the closing thereof. This dry air flows out from the exhaust chamber to the outside when the inlet door is opened, and prevents or reduces water vapor in the atmosphere from entering the exhaust chamber.

The dry air blowing mechanism blows dry air around the vacuum seal material when the inlet door is closed, and continues blowing the dry air until the pressure in the exhaust chamber becomes lower than atmospheric pressure. . As a result, the gas sucked from the gap between the vacuum seal material and the door at the time of starting the exhaust of the exhaust chamber,
It becomes dry air that does not contain water vapor, and it is possible to prevent suction of water vapor accompanying the start of exhaust.

After the exhaust chamber is sufficiently exhausted, the isolation valve is opened, the object to be processed is inserted from the exhaust chamber into the vacuum processing chamber,
Receive vacuum treatment.

FIG. 2 is a graph showing the experimental results of measuring the ultimate pressure when the exhaust chamber inlet door was opened for a predetermined time and then exhausted for a certain period of time. The horizontal axis represents the inlet of the exhaust chamber. Door opening time, the vertical axis is the ultimate pressure.

In the figure, line a is the case where no special measures are taken during the opening of the entrance door, and line b is the case where nitrogen is introduced into the exhaust chamber and released outside through the entrance door during the opening of the entrance door. The line c is the case where the dry air is introduced into the exhaust chamber and is discharged to the outside through the inlet door while the inlet door is open. It can be seen from the line a that the ultimate pressure greatly depends on the opening time of the entrance door, and the ultimate pressure increases as the opening time of the entrance door increases. On the other hand, when nitrogen or dry air is released during the opening of the entrance door, the ultimate pressure becomes almost constant and does not depend on the opening time of the entrance door as shown by the lines b and c. This indicates that the release of nitrogen or dry air reduced the amount of atmospheric air entering the exhaust chamber and the amount of water vapor adsorbed.

The release of nitrogen during opening of the inlet door may cause choking of an operator who inserts the object to be processed into the exhaust chamber. Therefore, dry air is used in the present invention.

FIG. 3 is a graph showing an experimental result obtained by measuring the ultimate pressure when the inlet door is opened while releasing the dry air, and then the inlet door is closed and exhaust is performed for a predetermined time. . In this graph, the line a is the case where the exhaust is performed after the inlet door is simply closed, the line b is the case where the exhaust is performed after the inlet door is fixed by screwing, and the line c is the case where the inlet door is closed. After that, the dry air is blown from outside to blow around the rubber gasket of the entrance door.

In this figure, when the air is exhausted after the inlet door is simply closed, the air is sucked from the very small gap between the gasket and the inlet door by the exhaust, and the water vapor in the air is exhausted. Since it is adsorbed in the room, the ultimate pressure does not decrease, that is, the exhaust time becomes long. On the other hand, when the screws are used, atmospheric suction is eliminated, and the ultimate pressure can be lowered. Similarly, when dry air is blown around the gasket, the water vapor around the gasket is removed from the vicinity of the gasket by the dry air, so only the dry air is sucked by the exhaust action in the exhaust chamber. Since the suction of water vapor is eliminated, the ultimate pressure can be lowered.

The present invention is based on the knowledge of the above experimental results that when the entrance door is opened, it releases dry air to the outside to reduce the invasion of water vapor in the atmosphere and to dry the vacuum sealing material around the circumference. By spraying air, adsorption of water vapor around the vacuum seal material is reduced.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the vacuum processing apparatus according to the present invention will be described below with reference to FIG. In FIG. 1, a vacuum processing chamber 1
An exhaust chamber 3 is connected to the via an isolation valve 2. An exhaust pipe 5 is connected to the exhaust chamber 3 via an exhaust valve 4,
An exhaust pump (not shown) is connected to the exhaust pipe 5. Further, the exhaust chamber 3 facing the inlet door 6 of the exhaust chamber 3
A ring-shaped groove 9 for accommodating a rubber packing 8 for vacuum seal is engraved on the flange surface 7, and a ring-shaped dry air blowing groove 10 is engraved on the outer side of the ring-shaped groove 9. . A dry air pipe 11 communicates with the dry air blowing groove 10, and a cutoff valve 12 is installed in the dry air pipe 11.

A dry air introducing pipe 13 is installed on the side wall of the exhaust chamber 3, and a shutoff valve 14 is attached to the dry air introducing pipe 13. A pressure gauge 15 for measuring the pressure inside the exhaust chamber is attached to the exhaust chamber 3.

Next, the operation of this embodiment will be described. The shutoff valve 14 is opened, and dry air is introduced into the exhaust chamber 3 through the dry air introducing pipe 13. When the pressure gauge 15 detects that the pressure in the exhaust chamber 3 has become equal to the atmospheric pressure due to the introduction of the dry air, the inlet door 6 is opened in response to this detection, and the object transporting device not shown is shown. Thus, the object to be processed is inserted into the exhaust chamber 3. During this time, the shut-off valve 14 remains open, so that the dry air is fed to the dry air introduction pipe 1
3 is discharged into the exhaust chamber 3 and flows out to the outside when the entrance door 6 is opened.

Thus, when the inlet door 6 is opened, the dry air continues to flow out from the exhaust chamber 3 to prevent or reduce the invasion of the atmosphere into the exhaust chamber 3.

Immediately after the object to be processed is inserted, the inlet door 6 is closed, and after the inlet door 6 is closed, the shutoff valve 14 is closed to stop the introduction of dry air into the exhaust chamber 3. Simultaneously with or after this, the shutoff valve 12 is opened, whereby the dry air is ejected from the dry air blowing groove 10, and the dry air is blown around the rubber packing 8. Next, the exhaust valve 4 is opened, the exhaust chamber 3 is exhausted, and the dry air blown around the rubber packing 8 is also exhausted together with the water vapor around the rubber packing 8.

When the pressure in the exhaust chamber 3 becomes lower than the atmospheric pressure, the shut-off valve 12 is closed according to the detection output of the pressure gauge 15 which detects the pressure. Of the dry air is stopped.

After that, when the exhaust chamber 3 is sufficiently exhausted to a predetermined pressure, the exhaust valve 4 is closed, the isolation valve 2 is opened, and the object to be treated in the exhaust chamber 3 is isolated from the isolation valve 2. It is inserted into the vacuum processing chamber 1 via. After this, the isolation valve 2 is closed, and the object to be processed is vacuum-processed in the vacuum processing chamber 1. Then, the above operation is repeated.

As described above, during the opening of the inlet door 6, the invasion of the atmosphere into the exhaust chamber is reduced by releasing the dry air, and when the inlet door 6 is closed, the dry air is blown around the rubber packing 8. Since the water vapor in the vicinity of the rubber packing 8 is exhausted by the attachment, the adsorption of the water vapor in the exhaust chamber can be sufficiently reduced, and the exhaust time can be greatly shortened.

In the above embodiment, the dry air blowing groove 10 is formed on the flange surface 7 of the exhaust chamber 3 and the dry air pipe 11 is formed in the exhaust chamber 3. However, the dry air blowing groove 10 and the dry air pipe 11 may be provided on the inlet door 6 side.

[0030]

As is apparent from the above description, according to the present invention, the dry air introduction mechanism for introducing dry air into the exhaust chamber and the vacuum sealing material are sandwiched between the opening and closing of the inlet door. Equipped with a dry air blowing mechanism that blows dry air around the vacuum seal material from the atmosphere side and continues blowing this dry air until the pressure in the exhaust chamber becomes lower than atmospheric pressure, and opens the entrance door. Occasionally, dry air is released to the outside to reduce the intrusion of water vapor in the atmosphere, and by spraying dry air around the vacuum seal material, the adsorption of water vapor around the vacuum seal material is reduced. Adsorption of water vapor in the room can be sufficiently reduced, and exhaust time can be greatly shortened.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing an embodiment of a vacuum processing apparatus according to the present invention.

FIG. 2 is a graph showing the relationship between the opening time of the entrance door and the ultimate pressure.

FIG. 3 is a graph showing the relationship between exhaust time and ultimate pressure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum processing chamber 2 Isolation valve 3 Exhaust chamber 4 Exhaust valve 5 Exhaust pipe 4, 5 Exhaust means 6 Entrance door 8 Vacuum sealing material 10 Dry air blowing groove 11 Dry air pipe 12 Shutoff valve 10, 11, 12 Dry air blowing mechanism 13 dry air introduction pipe 14 shutoff valve 13, 14 dry air introduction mechanism

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyasu Onoda 6-25-22 Sagamigaoka, Zama city, Kanagawa Shibaura Plant Sagami Plant

Claims (2)

[Claims] 1. An exhaust chamber provided with an inlet door and a vacuum sealing material for sealing the inlet door, an exhaust means for vacuum exhausting the exhaust chamber, and an exhaust chamber connected to the exhaust chamber via an isolation valve. In a vacuum processing apparatus comprising a vacuum processing chamber for vacuum processing the object to be processed inserted from, during the opening to closing of the inlet door, a dry air introduction mechanism for introducing dry air into the exhaust chamber, A dry air blowing mechanism that blows dry air around the vacuum seal material from the atmosphere side across the vacuum seal material and continues blowing the dry air until the pressure in the exhaust chamber becomes lower than atmospheric pressure. A vacuum processing apparatus comprising: 2. The dry air introducing mechanism introduces the dry air into the exhaust chamber and closes the inlet door until the pressure in the exhaust chamber becomes substantially equal to the atmospheric pressure prior to opening the inlet door. The vacuum processing apparatus according to claim 1, wherein the introduction of the dry air is stopped later.