JPH1054355A - Evacuation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent contaminant generated while regeneration of a cryopump is treated from invading into a vacuum chamber by arranging the cryopump on the upper part of a vacuum chamber through a gate valve, and arranging cover member for opening/closing a circulating passage formed between the gate valve and the cryopump in the circulating passage. SOLUTION: In the case where regeneration of a cryopump 3 is treated, a gate valve 2 is closed, and also the operation of the cryopump 3 is stopped after the cover member 4a of a cover opening/closing mechanism 4 is arranged on a closing position for covering the upper part of the gate valve 2. After it is left for about 30 minutes, current-carrying of a heater is started, purge gas is led from a purge gas leading-in line into the main body of the cryopump 3, and purge gas is discharged from a purge gas discharge line. During treating of regeneration, a material returned to an ordinary temperature in the cryopump 3 drops down into a vacuum chamber 1 as water drop and oil drop. Such all drop materials 12 are received on the upper surface of the cover member 4a, and thereby, it is possible to prevent the drop materials 12 from sticking on the valve element of the gate valve 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evacuation apparatus used for an apparatus such as a semiconductor manufacturing apparatus which needs to keep the inside clean, and more particularly to an evacuation apparatus using a cryopump.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus such as an ion implantation apparatus, it is necessary to maintain the inside of the apparatus in a clean and high vacuum state. Conventionally, a vacuum pumping apparatus using a cryopump has been frequently used as a high vacuum pump. ing. As one example, an end station of the ion implantation apparatus will be described below.

As shown in FIGS. 5 and 6, a cryopump 53 is provided via a gate valve 52 in a vacuum chamber 51 forming a wafer processing chamber. In the cylindrical vacuum chamber 51, a holding member 54 for holding a wafer 55 as an object to be processed is provided. The gate valve 52 is connected to the vacuum chamber 5 as shown in FIG.
A valve body 56 for opening and closing the flow passage between the cryopump 53 and the cryopump 53, a valve body driving unit 57 for driving the valve body 56 in the opening and closing direction, and a valve body 56 and a valve body driving unit 57 are swung. A link mechanism 58 operatively connected thereto and a power transmission mechanism 59 for transmitting the power of a power source (not shown) provided outside to the valve body driving unit 57 are provided.

The cryopump 53 has an adsorption surface (cold panel) cooled to an extremely low temperature, and condenses and adsorbs gas molecules flowing into the pump body on the adsorption surface, and exhausts the inside of the vacuum chamber 51. However, the amount of adsorption on the adsorption surface increases with the operation time of the cryopump 53, and the pump performance deteriorates when the cryopump 53 is operated for a long time. Therefore, the cryopump 53 needs regular regeneration.

[0005] The regeneration process of the cryopump 53 is performed with the gate valve 52 closed. In this regeneration process, the adsorption surface of the cryopump 53 is heated by a heater to return to room temperature, and a purge gas such as nitrogen gas is introduced into the cryopump 53, and the substance adsorbed on the adsorption surface is discharged to the outside together with the purge gas. This is the process of discharging.
When the regeneration process is completed, the cryopump 53 is started again, and the gate valve 52 is opened to evacuate the vacuum chamber 51.

[0006]

However, due to the layout problem for securing the installation space for the gate valve 52 and the cryopump 53, as shown in FIGS. Valve 5
In some cases, the cryopump 53 and the cryopump 53 must be installed in this order. In this case, the following inconvenience may occur with the above-described cryopump 53 regeneration processing.

That is, the gate valve 52 is closed during the regeneration process of the cryopump 53, but the substance adsorbed inside the cryopump 53 falls onto the gate valve 52 when the temperature is returned to normal temperature. Sometimes.
As a fallen object from the cryopump 53, an oily substance may be considered in addition to water droplets. This is because a substance such as a phthalate ester used as a plasticizer is released into a high vacuum from several cables provided in the vacuum chamber 51 and is adsorbed in the cryopump 53. This substance is dropped as oil droplets during the regeneration processing of the cryopump 53. Further, as a factor of the oil droplet, oil of a rotary pump for performing rough evacuation in the vacuum chamber 51 or the like can be considered.

When a fallen object (contaminant 60 in FIG. 7) from the cryopump 53 adheres to the gate valve 52, when the gate valve 52 is opened after the end of the regenerating process, the contaminant 60 is removed from the end face. And fall into the vacuum chamber 51. In the vacuum chamber 51, a holding member 54 for holding the wafer 55 is provided, and there is a problem that a substance dropped into the chamber contaminates the wafer 55 to cause a product defect, thereby lowering the yield. In particular, in recent years, miniaturization of devices has progressed, and reducing contaminants in the vacuum chamber 51 has become an important issue.

The present invention has been made in view of the above, and an object of the present invention is to provide a vacuum exhaust device capable of preventing contaminants generated during regeneration processing of a cryopump from entering a vacuum chamber. Is to do.

[0010]

According to a first aspect of the present invention, there is provided an evacuation apparatus, wherein a cryopump is provided above a vacuum chamber via a gate valve.
In order to solve the above-described problem, a movable member is provided to move between a closed position that enters the flow passage between the gate valve and the cryopump to cover an upper portion of the gate valve and an open position that is retracted from the flow passage. It is characterized by having a cover member provided.

According to the above configuration, the lid member that can be opened and closed is provided between the gate valve and the cryopump. The opening and closing drive of the lid member may be automatically performed using a drive source such as a motor, or an operation handle may be manually operated by an operator.

When the cryopump is regenerated, the lid member is closed (that is, the lid member is moved into the flow passage between the gate valve and the cryopump to move to the closed position covering the upper portion of the gate valve. By doing so, the contaminants falling from the cryopump during the regeneration process can be received by the upper surface of the lid member, and the contaminants can be reliably prevented from adhering to the gate valve. For this reason, even if the gate valve is opened after the end of the regeneration processing, no contaminants enter the vacuum chamber, and the inside of the vacuum chamber can be kept clean.

Further, during the evacuation operation of the cryopump, the above-mentioned lid member is opened (that is, the lid member is moved to the open position retracted from the flow passage between the gate valve and the cryopump). The conductance during evacuation is not deteriorated, and the evacuation capacity of the cryopump is hardly affected.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

In this embodiment, a case will be described in which the vacuum evacuation apparatus of the present invention is applied to a wafer processing chamber provided in an end station of an ion implantation apparatus.

As shown in FIGS. 1 and 3, in a cylindrical vacuum chamber 1 forming a wafer processing chamber, a holding member 14 for holding a wafer 13 to be processed is provided. Is provided with a cryopump 3 via a gate valve 2. A lid opening / closing mechanism 4 is provided between the gate valve 2 and the cryopump 3 to prevent a falling object from the cryopump 3 during the regeneration process from entering the vacuum chamber 1.

As shown in FIG. 1, the lid opening / closing mechanism 4 includes
A disk-shaped lid member 4a having a diameter slightly smaller than the diameter of the flow passage 5 between the gate valve 2 and the cryopump 3 is provided. The lid member 4 a is to enter the flow passage 5 between the gate valve 2 and the cryopump 3 during the regeneration of the cryopump 3 to cover the upper part of the gate valve 2. The lid member 4 a is retracted from the flow passage 5 and stands by in a lid chamber 6 provided in communication with the flow passage 5 during operation of the cryopump 3. .

The lid member 4a is driven by the lid drive mechanism 7 to move forward and backward. This lid drive mechanism 7 is shown in FIG.
As shown in FIG. 2, a rack 8 integrally attached to the lid member 4a, and a pinion 9 meshed with the rack 8
And so on. Note that a guide mechanism (not shown) for guiding the movement of the cover member 4a in the opening and closing direction is also provided in the cover chamber 6.

The rotation shaft 9a of the pinion 9 is drawn out of the lid chamber 6 (atmosphere side) through a vacuum feedthrough 11 including a bearing and an oil seal. At the end of the rotating shaft 9a pulled out, a manual handle 10 for an operator to manually open and close the lid member 4a is provided. Note that a gear may be provided at the end of the rotating shaft 9a instead of the manual handle 10, and the gear may be rotated forward or backward by a drive source such as a motor.

As the gate valve 2 located below the lid opening / closing mechanism 4, a commonly used gate valve can be used, and an example of the configuration is shown in FIG.
The gate valve 2 includes a valve element 21 for opening and closing the flow passage 5 between the vacuum chamber 1 and the cryopump 3, a valve element driving unit 22 for driving the valve element 21 in the opening and closing direction,
A link mechanism 23 that swingably connects the valve body 21 and the valve body drive unit 22 and a power transmission mechanism 24 that transmits the power of a power source (not shown) provided outside to the valve body drive unit 22 are provided. . As shown in the figure, the power transmission mechanism 24 horizontally rotates (swings) about a rotation shaft 25 introduced from the atmosphere side to the vacuum side via a vacuum feedthrough 27, and its rotation end. A long groove (a groove extending in a direction orthogonal to the opening / closing direction) formed in the valve body driving section 22
The swing arm 26 can be constituted by loosely fitting the swing arm 26a.

When the lid member 4a of the lid opening / closing mechanism 4 enters the flow passage 5 between the gate valve 2 and the cryopump 3, the entire upper surface of the valve body 21 of the gate valve 2 is
It is covered by a lid member 4a located above it.

In the above configuration, the regeneration process of the cryopump 3 will be described below.

In order to perform the regeneration process, the cryopump 3
Is provided with a heater for heating and vaporizing the condensed adsorbed material on the adsorbing surface. Further, the main body is provided with a purge gas introduction line for introducing a purge gas such as a nitrogen gas, a purge gas discharge line for discharging the purge gas, and the like. The heater is provided for the purpose of shortening the regeneration time of the cryopump 3, and it is of course possible to perform regeneration using a purge gas without using a heater.

At the start of the regeneration process, first, the gate valve 2 is closed, and the lid member 4a of the lid opening / closing mechanism 4 is driven in the closing direction as shown in FIG. The lid member 4a is arranged. Then, the operation of the cryopump 3 is stopped.

After that, the heater is left for about 30 minutes, and then the power supply to the heater is started. At the same time, the purge gas is introduced into the main body of the cryopump 3 from the purge gas introduction line, and the purge gas is discharged from the purge gas discharge line.
Then, it waits until the cryopump 3 returns to normal temperature.

During the regenerating process, the substance returned to the normal temperature in the cryopump 3 as described above may fall as water drops or oil drops. As shown in FIGS. Such falling objects (hereinafter referred to as contaminants) 12 are all covered members 4
It is received on the upper surface of a and does not adhere to the valve body 21 of the gate valve 2.

The upper surface of the lid member 4a is desirably processed in a saucer shape such that the center portion is lower than the peripheral end portion. Thus, it is possible to reliably prevent the substance attached to the lid member 4a from spilling from the peripheral end due to the vibration during the movement of the lid member 4a.

When the regeneration process is performed for a desired time and the regeneration of the cryopump 3 is completed, the introduction of the purge gas and the energization to the heater are stopped, and the regeneration process is terminated.

Thereafter, before the operation of the cryopump 3 is started, first, as shown in FIG.
Is driven in the opening direction, and is retracted to the open position inside the lid chamber 6 as shown by a virtual line in the figure. Thereafter, or substantially simultaneously with the opening operation of the lid member 4a, the gate valve 2 is opened. However, since the contaminant 12 is not attached to the gate valve 2, when the valve is opened, the contaminant 12 Will not fall into. Thereby, the inside of the vacuum chamber 1 can be kept clean.

Also, as described above, during operation of the cryopump 3, since the lid member 4 a is retracted to a position where the flow passage 5 between the gate valve 2 and the cryopump 3 is not blocked, exhaust is performed. The conductance at the time is not deteriorated, and the vacuum pumping capacity of the cryopump 3 is not affected at all.

Incidentally, in order to prevent the regeneration of the cryopump 3 in a state where the cover member 4a is not closed,
It is desirable to provide an interlock mechanism for inhibiting the regeneration process of the cryopump 3 when a sensor (not shown) for detecting the closed state of the lid member 4a does not detect the closed state.

In order to prevent the operation of the cryopump 3 when the cover member 4a is not open, a sensor (not shown) for detecting the open state of the cover member 4a.
It is desirable to provide an interlock mechanism for inhibiting the operation of the cryopump 3 when the open state is not detected.

In this embodiment, the lid member 4a is opened and closed by the lid driving mechanism 7 using the rack 8 and the pinion 9. However, the present invention is not limited to this. Mechanism, for example, the gate valve 2
A driving mechanism similar to the mechanism for moving the valve body driving unit 22 in the opening and closing direction can be used.

Further, in this embodiment, an example is shown in which the vacuum evacuation apparatus of the present invention is applied to a wafer processing chamber of an ion implantation apparatus. However, the present invention is not limited to this. The vacuum evacuation apparatus of the present invention can be suitably used particularly for a semiconductor manufacturing apparatus such as the above-described ion implantation apparatus, but can also be applied to other apparatuses which are adversely affected by intrusion of contaminants.

[0035]

According to the first aspect of the present invention, there is provided a vacuum evacuation apparatus.
As described above, the lid that is movable between the closed position that enters the flow passage between the gate valve and the cryopump and covers the upper part of the gate valve, and the open position that is retracted from the flow passage. This is a configuration including members.

Therefore, at the time of regeneration processing of the cryopump, by moving the lid member to the closed position, contaminants falling from the cryopump during the regeneration processing are received by the upper surface of the lid member, and the contaminants enter the vacuum chamber. Intrusion can be reliably prevented. Therefore, there is an effect that the inside of the vacuum chamber can be kept clean. In addition, during the evacuation operation of the cryopump, by moving the lid member to the open position, the conductance at the time of evacuation is not deteriorated, and the evacuation ability of the cryopump is hardly affected. Play together.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of the present invention, and is a schematic longitudinal sectional view showing a configuration of a lid opening / closing mechanism.

FIG. 2 is a schematic cross-sectional view showing a configuration of the lid opening / closing mechanism.

FIG. 3 is a schematic front view of a wafer processing chamber (vacuum exhaust device) provided with the lid opening / closing mechanism.

FIG. 4 is a schematic longitudinal sectional view showing a configuration of a gate valve in the wafer processing chamber.

FIG. 5 is a schematic diagram showing a configuration of a conventional wafer processing chamber.

FIG. 6 is a schematic front view of a conventional wafer processing chamber.

FIG. 7 is a schematic longitudinal sectional view showing a configuration of a conventional gate valve of a wafer processing chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Gate valve 3 Cryopump 4 Lid opening / closing mechanism 4a Lid member 5 Flow path between gate valve and cryopump 6 Lid chamber 7 Lid drive mechanism 8 Rack 9 Pinion 12 Contaminant

Claims (1)

[Claims] An evacuation apparatus in which a cryopump is provided above a vacuum chamber via a gate valve, wherein the evacuator enters a flow passage between the gate valve and the cryopump to cover the upper part of the gate valve. An evacuation apparatus comprising: a lid member movably provided between a closed position and an open position retracted from the flow passage.