JPH1096074A - Substrate treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage and emission of malodor from a vacuum preliminary chamber to the atmosphere at the time of opening a flap valve while suppressing the degradation in throughput to a lower level. SOLUTION: This substrate treating device has a flap valve driving device which opens and closes the flap valve 4 and automatically opens the flap valve 4 to an intermediate position between its close position and open position when the pressure at the time of venting of the vacuum preliminary chamber 2 attains nearly the atm. pressure, a discharge cover 92 which covers the circumference of the aperture of the flap valve 4 opened to the intermediate position and a discharge duct 94 which is connected to this discharge cover 92 and forcibly discharges the inside of the discharge cover 92.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus having a structure in which a substrate subjected to processes such as ion implantation, plasma etching, and plasma CVD in a processing chamber is taken out to the atmosphere through a vacuum auxiliary chamber. More specifically, the present invention relates to a means for suppressing an unpleasant odor generated from a substrate immediately after processing from leaking into the atmosphere from the pre-vacuum chamber when the flap valve is opened.

[0002]

2. Description of the Related Art FIG. 11 shows a plan view of a conventional example of this type of substrate processing apparatus.

This substrate processing apparatus is an example of an ion doping apparatus (non-mass separation type ion implantation apparatus), and includes a processing chamber 104 which is evacuated to a vacuum (for example, about 10 ^-5 to 10 ^-7 Torr). , And an ion source 108 attached thereto. Holder 1 in processing chamber 104
A substrate (for example, a substrate for a liquid crystal display or a semiconductor substrate) 20 is mounted on the substrate 06, and an ion beam 110 extracted from the ion source 108 is irradiated on the substrate 20 to apply, for example, phosphorus (P) or boron (B) to the substrate 20. It can be injected and processed.

A transfer chamber 112 is connected to the processing chamber 104 via a gate valve 120 in this example. In the transfer chamber 112, a transfer robot 114 having an arm 116 and transferring the substrate 20 placed thereon between the processing chamber 104 and two vacuum preparatory chambers 2 described later is provided. .

In this example, two vacuum preparatory chambers 2 are adjacent to the transfer chamber 112 via gate valves 122, respectively. Each of the vacuum preparatory chambers 2 is separated from the atmosphere by a flap valve 4. A flap valve refers to a valve that opens and closes by rotating about a rotation axis at one end of a valve body, such as a one-sided door. The vacuum preparatory chamber 2 is a chamber for taking the substrate 20 in and out of the processing chamber 104 and the transfer chamber 112 without opening the processing chamber 104 and the transfer chamber 112 to the atmosphere. I do.

In front of each flap valve 4, in this example:
Transfer robots 124 each having an arm 126 and carrying in and out the substrate 20 placed on the vacuum preliminary chamber 2 are provided.

Referring to FIG. 12, the pre-vacuum chamber 2 has an opening 3 for carrying out the substrate 20, and the flap valve 4 described above is provided in the opening. 5 is an O-ring for the vacuum seal. The flap valve 4 is rotated and opened and closed as shown by an arrow A by a flap valve driving device (not shown). Reference numeral 6 denotes the rotation axis.

The pre-vacuum chamber 2 is provided with the gate valve 122 described above.
To open the substrate 2 between the transfer chamber 112 and the processing chamber 104.
Before carrying 0, the air is evacuated to about 10 ⁻² to 10 ⁻³ Torr, for example, by an evacuation apparatus (not shown) through the exhaust valve 10. Before the flap valve 4 is opened and the substrate 20 is carried out to the atmosphere, a vent gas 13 is introduced through the vent valve 12 to return to the atmospheric pressure (that is, vented). Specifically, after closing the exhaust valve 10, the vent valve 12 is opened, and the vent gas 13 is introduced into the pre-vacuum chamber 2 to return to the atmospheric pressure. The vent gas 13 is, for example, a nitrogen gas, and its pressure is somewhat positive (for example, 0.5 k in gauge pressure).
g / cm ² ). Whether or not the pre-vacuum chamber 2 has reached the atmospheric pressure is detected by a pressure switch (not shown) connected to the pre-vacuum chamber 2, and after the detection, the flap valve 4 is opened.

A ceiling lid 8 is provided at the ceiling of the vacuum preparatory chamber 2. The ceiling lid 8 is elastically pressed against the vacuum preparatory chamber 2 by a pressure relief mechanism 24 having a spring 22. When the pressure in the vacuum preparatory chamber 2 exceeds a certain level, the ceiling lid 8 is lifted to reduce the pressure. It is a safety valve system that comes off. 9 is an O-ring for vacuum sealing. In this example, substrate support pins 18 are provided at the bottom of vacuum preparatory chamber 2.
And a substrate raising / lowering mechanism 16 for raising and lowering the loaded substrate 20 is provided.

An example of the overall operation of the substrate processing apparatus shown in FIG. 11 will be described.
The substrate 20 is transferred into the processing chamber 104 along a path indicated by arrows e to g in FIG. 11, and the substrate 20 is irradiated with an ion beam 110 to perform processing such as ion implantation. The substrate 20 after the ion implantation is carried out to the atmosphere along a route indicated by arrows h to j in FIG.

In the above example, two vacuum preparatory chambers 2 and two transfer robots 124 are provided in order to further increase the throughput. good. In some cases, the transfer chamber 112 is omitted, and the processing chamber 104 and the pre-vacuum chamber 2 are adjacent to each other via a gate valve.

[0012]

As described above, the substrate 20 immediately after the ion implantation of phosphorus, boron or the like emits an unpleasant odor.
It continues after being transported inside. And when this unpleasant odor opens the flap valve 4 and takes out the substrate 20 to the atmosphere,
There is a problem that the air leaks from the flap valve 4 into the atmosphere together with the vent gas 13 and reaches the worker's environment, giving the worker discomfort. In particular, in recent years, the substrate 20 tends to have a large area, and accordingly, the amount of off-flavors emitted therefrom also tends to increase.

Further, in the conventional apparatus, the pressure switch is used for detecting the atmospheric pressure in the pre-vacuum chamber 2 as described above.
Due to the error of the pressure switch, the pre-vacuum chamber 2 may be detected as the atmospheric pressure in a somewhat vacuum state, and even if the flap valve 4 is opened in this state, the force of the atmosphere pushing the flap valve 4 from outside ( In other words, the flap valve 4 does not open due to a large suction force of the flap valve 4 due to the vacuum, so that the flap valve 4 is normally opened after the vacuum preliminary chamber 2 is slightly pressurized with the vent gas 13. Therefore, at the moment when the flap valve 4 is opened, a large amount of the vent gas 13 containing an offensive odor is released into the atmosphere at a stretch, so that there is a problem that the offensive odor easily leaks into the atmosphere.

Further, in order to reduce the leakage of the unpleasant odor from the pre-vacuum chamber 2 to the atmosphere, a vent gas 13 is introduced to once vent the pre-vacuum chamber 2 to the atmospheric pressure. The so-called two-time venting method, in which the odor contained in the vent gas 13 is exhausted to a desired place by a vacuum exhaust device, and then the vacuum preparatory chamber 2 is vented again and the substrate 20 is taken out to the atmosphere, is also attempted. However, in that case, there is a problem that the throughput (processing capacity) is greatly reduced. In other words, the evacuation and venting of the pre-vacuum chamber 2 are the most time-consuming steps in the entire processing steps, and the processing is doubled, so that the throughput is greatly reduced.

It is to be noted that the off-flavor from the substrate 20 immediately after the above-described processing is more or less generated immediately after the substrate 20 is subjected to processing other than ion implantation, for example, plasma etching or plasma CVD.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a substrate processing apparatus capable of suppressing an unpleasant odor from leaking into the atmosphere from a pre-vacuum chamber when a flap valve is opened, while suppressing a decrease in throughput. And

[0017]

A substrate processing apparatus according to the present invention opens and closes the flap valve and, when the pressure at the time of venting the vacuum preparatory chamber becomes substantially atmospheric pressure, moves the flap valve to its closed position. And a flap valve driving device that automatically opens to an intermediate position between the flap valve and an exhaust cover that covers the opening of the flap valve that opens to the intermediate position. An exhaust duct for forcibly exhausting the inside is provided.

According to the above configuration, when the vacuum auxiliary chamber is almost at atmospheric pressure during venting of the vacuum auxiliary chamber, the flap valve is automatically opened to the intermediate position by the flap valve driving device. As a result, the pre-vacuum chamber is automatically opened to the atmosphere, so that the pre-vacuum chamber does not fall into a pressurized state due to the vent gas. Therefore, it is possible to prevent a large amount of vent gas mixed with an unpleasant odor from being blown out of the vacuum preliminary chamber at a stretch. In addition, the vent gas containing an unpleasant odor in the pre-vacuum chamber is prevented from leaking into the atmosphere by the exhaust cover covering the opening of the flap valve opened at the intermediate position, and is forced to the desired gas through the exhaust duct. Discharged to the place. As a result, when the flap valve is opened, an unpleasant odor can be suppressed from leaking out of the pre-vacuum chamber into the atmosphere.

In addition, the time for keeping the flap valve at the intermediate position is, for example, about several seconds, which is much shorter than the time required for performing the conventional two-time venting. Can be suppressed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a longitudinal sectional view showing an example of the vicinity of a pre-vacuum chamber of a substrate processing apparatus according to the present invention, and corresponds to an EE section in FIG. FIG. 2 is a diagram showing a main part of an example of a flap valve driving device constituting the present invention. FIG. 3 is an enlarged perspective view showing the periphery of the flap valve opened to the intermediate position in FIG. The configuration of the entire substrate processing apparatus
For example, since it is the same as that shown in FIG. 11, it will be referred to. The same or corresponding parts as those in the conventional example of FIGS. 11 and 12 are denoted by the same reference numerals, and differences from the conventional example will be mainly described below.

The substrate processing apparatus of this embodiment opens and closes the above-mentioned flap valve 4 and, when the pressure at the time of venting of the pre-vacuum chamber 2 becomes almost atmospheric pressure, moves the flap valve 4 to its closed position and to its open position. A flap valve driving device 25a which automatically opens to an intermediate position between the two positions, an exhaust cover 92 provided near the lower portion of the flap valve 4 and covering around an opening of the flap valve 4 opened to the intermediate position. An exhaust duct 94 connected to the exhaust cover 92 and forcibly exhausting the inside of the exhaust cover 92 is provided. Further, the gas inlet 11 for introducing the vent gas 13 is provided at substantially the same height as the substrate 20 on the substrate support pins 18 at the time of venting, and is provided at a position facing the flap valve 4 with the substrate 20 interposed therebetween. .

Referring mainly to FIG. 2, the flap valve driving device 25a includes a double-acting cylinder 26a for opening and closing the flap valve 4, and a piston 27 of the double-acting cylinder 26a.
And a cylinder control circuit 34a for controlling the double-acting cylinder 26a, which converts a reciprocating linear motion as shown by arrow B into a reciprocating rotational motion (opening and closing motion) as shown by arrow A of the flap valve 4. ing. Double acting cylinder 26a
Is a double rod type in this example, and the piston 27
Have rods 28 and 29 on both sides. The double-acting cylinder 26a is a pneumatic (air) cylinder, which is preferable because it can lightly move the piston 27 in a free state, but may be a hydraulic cylinder. In that case, the cylinder control circuit 34a or 34b described below may be of a hydraulic type.

The connecting mechanism 30 is of a rack and pinion type in this example, and is connected to the rod 28 of the double-acting cylinder 26a.
And a pinion 32 connected to the flap valve 4 via the rotary shaft 6 and meshing with the rack 31. However, this coupling mechanism 3
0 may be configured using a link mechanism.

The cylinder control circuit 34a includes a compressed air source 3
6 and a two-position switching valve 38 for switching and supplying compressed air therefrom to the ports a and b of the double-acting cylinder 26a.
And a two-position switching valve 40 connected between the two-position switching valve 38 and the port b of the double-acting cylinder 26a.
In this example, the two-position switching valve 38 is a four-port latch type (self-holding type) double solenoid valve, but may be a five-port type. In this example, the two-position switching valve 40 is a three-port latch type (self-holding type) double solenoid valve. The reason why the two two-position switching valves 38 and 40 are of the latch type is that the current position is maintained in the event of a power failure, and at that time the transfer robot 124 inserts the arm 126 into the vacuum auxiliary chamber 2 by any chance. However, this is to prevent the flap valve 4 from closing and the arm 126 being pinched by it.

When the two-position switching valve 38 is switched to the open side,
Compressed air is supplied to the port a behind the double-acting cylinder 26a, the piston 27 moves forward, and the flap valve 4 opens. In this state, for example, the transfer robot 124 on the atmospheric pressure side
Accordingly, the substrate 20 can be carried in and out of the vacuum preparatory chamber 2 through the opened flap valve 4. When the two-position switching valve 38 is switched to the closed or intermediate side and the two-position switching valve 40 is switched to the closed side, the double-acting cylinder 26a
Compressed air is supplied to the port b in front of the
Moves rearward, and the flap valve 4 is closed. When the two-position switching valve 38 is closed or switched to the intermediate side, and the two-position switching valve 40 is switched to the intermediate side, both ports a and b of the double-acting cylinder 26a are opened to the atmosphere, so that the piston 27 is in a free state. .

At the rear of the double-acting cylinder 26a, a force is constantly applied to the flap valve 4 in the opening direction, the piston 27 of the double-acting cylinder 26a is in a free state, and the pressure in the vacuum preliminary chamber 2 is substantially large. When the air pressure is reached, the flap valve 4
Flap valve 4 against the force sucked into vacuum pre-chamber 2
Is opened to an intermediate position between the closed position and the open position.

The valve opening mechanism 44a has a rod 47 and a spring (compression coil spring) 46, and the elastic force of the rod 47 and the rod 29 of the double-acting cylinder 26a
7 and the rod 28 are always pushed forward as shown by the arrow C, thereby constantly applying a force to the flap valve 4 in its opening direction. 48 is a stopper. The pushing force of the valve opening mechanism 44a can be adjusted by the spring constant and the amount of compression of the spring 46, and the pushing distance (that is, the opening degree of the intermediate position of the flap valve 4) can be adjusted by the position of the stopper 48. In this example, just before the vacuum preparatory chamber 2 is changed from vacuum to atmospheric pressure, the force for opening the flap valve 4 by the valve opening mechanism 44a overcomes the force for suctioning the flap valve 4 by the vacuum, and the flap valve 4 is moved to the intermediate position. Is set to open. Since there is a stopper 48,
The valve opening mechanism 44a does not open the flap valve 4 beyond the intermediate position. Further, the double-acting cylinder 26a can generate a force for closing the flap valve 4 against the pushing force of the valve opening mechanism 44a.

With the above configuration, in this embodiment, the flap valve 4 has an opening of 0 degree when closed, an opening of about 10 degrees at an intermediate position, and an opening when opened (fully opened). Drive so as to be about 90 degrees.

The conventional flap valve driving device merely drives the flap valve 4 to fully close and fully open. Instead of the double rod type double acting cylinder 26a, a single rod type double acting cylinder is used. Used. In addition, components corresponding to the two-position switching valve 40 and the valve opening mechanism 44a are not provided.

The control of the vent valve 12 and the cylinder control circuit 34a at the time of venting of the pre-vacuum chamber 2 is performed by a control circuit 64. That is, at the time of venting, the cylinder control circuit 3
4a, and more specifically, its two-position switching valve 38.
And 40 are switched to the intermediate side, and the double-acting cylinder 26a
After the piston 27 is in a free state, the vent valve 12 is opened to control the vent gas 13 to be introduced into the pre-vacuum chamber 2. Further, it is preferable that the control circuit 64 controls the vent gas 13 to be continuously introduced into the pre-vacuum chamber 2 even when the flap valve 4 is opened to the intermediate position at the time of venting, for the reason described later. Note that the control circuit 64 may be provided as a function in another control circuit, instead of being provided alone, and is usually used as such.

The exhaust cover 92 is mainly described with reference to FIG.
The space from the lower end of the flap valve 4 opened at the intermediate position and the vicinity of both left and right sides to the wall surface of the vacuum preparatory chamber 2 (more specifically, to the opening 3 thereof) is covered. The exhaust cover 92 has a box shape in which left and right side surfaces 92c are longer than the front surface 92a and the rear surface 92b.
The upper side faces the lower end of the flap valve 4 opened at the intermediate position with a small gap 98 therebetween, and the left and right side faces 92c face the side faces of the flap valve 4 with a small gap therebetween. The rear surface 92b is connected to the wall surface of the pre-vacuum chamber 2 without any gap (see FIG. 1). An exhaust duct 94 is connected to the bottom surface 92d. When the flap valve 4 is at the intermediate position, the gap 98 between the tip of the flap valve 4 and the upper side of the front surface 92a of the exhaust cover 92 is minimized.

In the embodiment shown in FIG. 1, an exhaust fan 96 is provided in the middle or at the end of the exhaust duct 94.
This will force exhaust. When there is a common exhaust duct such as in a factory, the exhaust duct 94 may be directly connected to the common exhaust duct without providing the exhaust fan 96. Further, an adsorbent chamber (deodorizing chamber) 95 may be provided in the middle of the exhaust duct 94, where the odor is removed by adsorption, and then exhausted to a desired place.

Further, in this embodiment, as shown in FIG.
A detector 52 is provided for detecting that the flap valve 4 has opened at least to the intermediate position. The detector 52 is of a photoelectric type in this example, and includes a light emitter 54 emitting light 56, a light receiver 58 receiving the light 56, and a rotating shaft 6 of the flap valve 4.
And a light-shielding plate 60 attached to the light-shielding plate 60. The light-shielding plate 60 is arranged so as to block the light 56 only when the flap valve 4 is in the closed position. When the flap valve 4 opens above the intermediate position, the light 56 enters the light receiver 58 without being blocked by the light shielding plate 60, so that it is possible to detect that the flap valve 4 has opened above the intermediate position.

The flap valve 4 can be used without using the light shielding plate 60.
Alternatively, the light 56 may be directly shielded. Further, instead of the photoelectric detector 52, another method, for example, a contact type,
A detector such as a proximity switch type may be used.

An example of the overall operation around the pre-vacuum chamber 2 will be described. First, when loading the substrate 20 into the vacuum preparatory chamber 2, the two-position switching valve 38 is switched to the open side. as a result,
The flap valve 4 is opened to the fully open position by the double-acting cylinder 26a.

Next, when evacuating the vacuum preparatory chamber 2, the two-position switching valve 38 is closed or switched to the intermediate side, and the two-position switching valve 40 is switched to the closed side. As a result, the double action cylinder 26a causes the flap valve 4 to open the valve opening mechanism 44.
It is closed to the closed position by overcoming the force of a. In this state, the exhaust valve 10 is opened to evacuate the pre-vacuum chamber 2. Thereafter, the gate valve 122 is opened to exchange the substrate 20 with the processing chamber 104 (see FIG. 11).

At the time of venting the vacuum preparatory chamber 2, first, the exhaust valve 10 is closed, and the two-position switching valve 38 is closed or switched to the intermediate side (this has already been switched in the previous operation). Further, the two-position switching valve 40 is switched to the intermediate side. Thereby, the piston 27 of the double-acting cylinder 26a is
Is in a free state, but since the vacuum preparatory chamber 2 is under vacuum, the flap valve 4 is sucked into the vacuum preparatory chamber 2 and does not open. Thereafter, the vent valve 12 is opened, and the vent gas 13 is introduced into the pre-vacuum chamber 2 to start venting.

Just before the venting advances and the pre-vacuum chamber 2 reaches the atmospheric pressure, the force for opening the flap valve 4 by the valve opening mechanism 44a overcomes the force for suctioning the flap valve 4 by the vacuum, and the flap valve 4 Automatically opens to position (ie, without depending on people or controls). As a result, the pre-vacuum chamber 2 is automatically opened to the atmosphere.
Accordingly, a trouble in which the vacuum preparatory chamber 2 is excessively pressurized can be reliably prevented.

The fact that the flap valve 4 has opened to the intermediate position means that
For example, it is detected by the detector 52. When the flap valve 4 opens to the intermediate position, the vacuum preparatory chamber 2 becomes atmospheric pressure,
Even if a pressure switch is not provided unlike the related art, the detector 52 can easily and reliably detect that the pre-vacuum chamber 2 has reached the atmospheric pressure. At this intermediate position, in response to a signal from the detector 52, the vent valve 12 may be closed to stop the vent gas 13, or the vent gas 13 may be kept flowing without doing so. After that, the two-position switching valve 38
May be switched to the open side to open the flap valve 4 fully.

This substrate processing apparatus is provided with the flap valve driving device 25a as described above. When the flap valve 4 is automatically opened to the intermediate position at the time of venting, the vacuum preliminary chamber 2 is automatically opened to the atmosphere. Vent gas 13
Thus, the vacuum preparatory chamber 2 does not fall into a pressurized state. Therefore, it is possible to prevent a large amount of vent gas 13 mixed with an odor from being blown out of the vacuum preparatory chamber 2 at a stretch.

Moreover, the vent gas 13 containing an unpleasant odor in the pre-vacuum chamber 2 flows around the opening of the flap valve 4 opened at the intermediate position (ie, the space between the flap valve 4 and the wall surface of the pre-vacuum chamber 2). The gas is prevented from leaking into the atmosphere by an exhaust cover 92 covering the cover, and is forcibly discharged to a desired place through an exhaust duct 94.

As a result, when the flap valve 4 is opened, the unpleasant odor accumulated in the pre-vacuum chamber 2 can be prevented from leaking from the pre-vacuum chamber 2 to the atmosphere. as a result,
It is possible to prevent the off-flavor from leaking into the environment of the worker.

The off-flavor generated from the substrate 20 immediately after the processing is as follows:
Since a relatively large amount of gas is generated in the process of returning the atmosphere to the atmospheric pressure, that is, in the process of venting the pre-vacuum chamber 2 to the atmospheric pressure, the flap valve 4 is opened to the intermediate position and introduced into the pre-vacuum chamber 2 at the time of venting. After exhausting all the vent gas 13,
The unpleasant odor generated from the substrate 20 is small.

Therefore, during the time when the flap valve 4 is kept at the intermediate position, the vent gas 13 accumulated in the pre-vacuum chamber 2 at the time of venting is discharged from the exhaust cover 92 and the exhaust duct 94.
It is sufficient to secure at least the time required for exhausting all of the gas through the, for example, about several seconds, at most 10 seconds or less, and the time that is increased when performing the conventional two vents (this is, for example, , It takes only a few minutes at least.)
Even if is once opened to the intermediate position, a decrease in throughput can be kept small.

It is preferable to keep introducing the vent gas 13 into the pre-vacuum chamber 2 even while the flap valve 4 is opened to the intermediate position. Since the vent gas 13 mixed with the off-flavor can be flushed toward the flap valve 4, the vent gas 13 mixed with the off-odor can be discharged in a shorter time. Moreover, in this case, if the gas inlet 11 is provided at a position facing the flap valve 4 with the substrate 20 interposed therebetween as described above, the vent gas 13 extends along the front and back surfaces of the substrate 20 as shown in FIG.
Can be blown evenly and evenly,
An unpleasant odor generated from the substrate 20 can be quickly removed and discharged to the exhaust cover 92. In addition, by blowing the surface of the substrate 20 with the vent gas 13, it is possible to prevent dust from adhering to the surface of the substrate 20.

FIG. 4 schematically shows the flow of the vent gas 13 and the like. As can be seen from this figure, the flap valve 4 opened to the intermediate position has a louver-like effect of bending the flow of the vent gas 13 downward to guide the vent gas 13 to the exhaust cover 92 below, and heads downward. Combined with the flow of the vent gas 13 and the action of forcibly exhausting the inside of the exhaust cover 92, the air 1 flows from the gap 98 between the flap valve 4 and the exhaust cover 92 and the wall surface of the vacuum preliminary chamber.
Since 00 is sucked into the exhaust cover 92, it is possible to further suppress the vent gas 13 containing an unusual odor from leaking out from the gap 98 or the like. When removing the substrate 20, the introduction of the vent gas 13 is stopped, and the flap valve 4 is fully opened as described above.

Note that the forced exhaust by the exhaust duct 94 is started at least immediately before the flap valve 4 is opened to the intermediate position, and is continued while the flap valve 4 is opened to the intermediate position. It is preferable to continue the operation while the flap valve 4 is open regardless of the intermediate position and the fully open position. Further, in the case where the evacuation and venting of the pre-vacuum chamber 2 are frequently repeated, the evacuation may always be performed, and the control is simplified.

Since the exhaust cover 92 does not cover around the opening of the flap valve 4 which is fully opened, but covers around the opening of the flap valve 4 at the intermediate position, the depth L and the height of the front surface 92a are set. H (see FIG. 3) can be reduced. Accordingly, it is possible to easily prevent the exhaust cover 92 from interfering with the arm 126 of the transfer robot 124 on the atmospheric pressure side while keeping the gap between the flap valve 4 and the exhaust cover 92 small. From this perspective,
It is preferable that the opening of the flap valve 4 at the intermediate position is not so large, for example, about 10 degrees as described above.

The flap valve driving device 2 as described above
According to 5a, at the time of venting, the flap valve 4 is automatically opened to the intermediate position, so that it is possible to reliably prevent the pre-vacuum chamber 2 from being pressurized, so that a safety valve is not required. Therefore, the ceiling lid 8 does not need to be a safety valve type as in the conventional example, and the fixing member 62 as in the example shown in FIG.
Therefore, it is possible to prevent a problem of vacuum leakage that is likely to occur when the safety valve system is used. Further, it is also possible to similarly prevent a trouble of vacuum leakage that is likely to occur when a normal safety valve used in a pneumatic circuit is used in the vacuum preparatory chamber 2 that is also evacuated.

When the ceiling lid 8 is of a fixed type, the periphery thereof can be fixed. Therefore, compared with the case of using a safety valve system as in the conventional example, the ceiling lid 8 is evacuated.
, The thickness of the ceiling lid 8 can be reduced, and the size and weight of the ceiling lid 8 can be reduced.

Instead of the valve opening mechanism 44a using the spring 46 as described above, for example, as shown in FIG.
The valve opening mechanism 44b using the weight 50 may be used, or both may be used in combination. The valve opening mechanism 44b in FIG. 6 always applies a force to the flap valve 4 in the opening direction by the weight 50, the piston 27 of the double-acting cylinder 26a is in a free state, and the pressure in the When the atmospheric pressure is reached, the flap valve 4 opens to an intermediate position against the force of the suction of the flap valve 4 toward the pre-vacuum chamber 2.
At the intermediate position, the rotational moment due to the weight of the flap valve 4 and the rotational moment in the opposite direction due to the weight 50 are balanced, and the flap valve 4 stops. This valve opening mechanism 44b is
Although it has an advantage that the structure is simple, from the viewpoint of preventing the flap valve 4 from swinging back and forth, the above-described valve opening mechanism 44a using the spring 46 is more effective. This is preferable. When the valve opening mechanism 44b is used, unlike the case of the valve opening mechanism 44a, it is not necessary to always push the piston 27 of the double-acting cylinder 26a forward. A single rod type double acting cylinder may be used.

In place of the cylinder control circuit 34a using the two two-position switching valves as described above, for example, FIG.
A cylinder control circuit 34b including a three-position switching valve 41 of an intermediate position exhaust type as shown in FIG. When the three-position switching valve 41 is switched to the open side, compressed air is supplied to the rear port a to open the flap valve 4, and when switched to the closed side, compressed air is supplied to the front port b and the flap valve 4 Is closed and the switch is made to the intermediate position, air is discharged from the double-acting cylinder 26a, and the piston 27 is in a free state. This cylinder control circuit 34b has the advantage that only one switching valve is required, but when a power failure occurs, the three-position switching valve 41 switches from the open position to the intermediate position, and the robot arm 126 is moved by the flap valve 4. Because there is a risk of pinching,
From this viewpoint, it can be said that the cylinder control circuit 34a shown in FIG. 2 is more secure and preferable.

In the above-described embodiment, the valve opening mechanism 44a or 44b opens the flap valve 4 not only to the flap valve 4 but also to the free state of the double-acting cylinder 26a in order to open the flap valve 4 to the intermediate position. This is a structure for moving a certain piston 27. Therefore, by the resistance of this piston 27,
There is room for improvement in that a large force is required for the valve opening mechanism 44a or 44b. Therefore, an embodiment in which this point is further improved will be described mainly with reference to FIGS. In the following embodiment, the detector 52 having the light shielding plate 60 attached to the rotary shaft 6 of the flap valve 4 and the control circuit 64 for vent control are provided similarly to the previous embodiment. Is the same as in the previous embodiment, and the description thereof will be omitted below. Further, FIG. 1 is referred to for the pre-vacuum chamber 2.

In this embodiment, the double-acting cylinder 2
6a, a three-position cylinder 70 for driving the flap valve 4 to a closed position, an open position and an intermediate position between them.
It has. More specifically, the three-position cylinder 70 is a double-acting two-stage cylinder having two pistons 71 and 72, and has four ports a to d, as shown in FIG. . 73 is an output rod. The three-position cylinder 70 is a pneumatic (air) cylinder in this example, but may be a hydraulic cylinder. In that case,
What is necessary is just to make the cylinder control circuit 34c mentioned later a hydraulic type.

The output rod 7 of the three-position cylinder 70
A frame 74 is attached to the distal end of 3. This frame 74 is a quadrangle in the illustrated example, but has other shapes,
For example, the shape may be circular or elliptical. The frame 74 is reciprocated linearly by the three-position cylinder 70 as shown by an arrow D in FIG.

The reciprocating linear motion of the frame 74 as indicated by the arrow D is converted by the link mechanism 76 into a reciprocating rotary motion (opening / closing motion) of the flap valve 4 as indicated by the arrow A described above. The link mechanism 76 includes an arm 78 connected to one end of the rotary shaft 6 of the flap valve 4, and an engagement portion provided at the tip thereof and located in the frame 74 and engaged with the frame 74. And a roller 80.

In this example, an arm 82 is connected to the other end of the rotary shaft 6 of the flap valve 4. The arm 82 is elastically pushed by the above-described valve opening mechanism 44 a having a spring, and the flap valve 4 is connected to the arm 82. The force is always applied in the opening direction. However, instead of the valve opening mechanism 44a, the above-described valve opening mechanism 44b having a weight may be used, or both may be used in combination.

The output rod 7 of the three-position cylinder 70
In this example, the frame 74 attached to the position 3 corresponds to the position corresponding to the closed position of the flap valve 4 (see FIG. 9A) and the position corresponding to the open position of the flap valve 4 by the cylinder control circuit 34c shown in FIG. (See FIG. 9C) and the position corresponding to the intermediate position of the flap valve 4 (see FIG. 9B).

The cylinder control circuit 34c includes a compressed air source 36 as described above, pressure reducing valves 84 and 86 for reducing the compressed air from the compressed air source 36 to two pressures P1 and P2 (where P1 <P2). Two-position switching valves 88 and 90 are respectively connected. 2-position switching valve 88
Is a four-port latch type (self-holding type) double solenoid valve in this example, and the two-position switching valve 90 is a three-port latching type (self-holding type) double solenoid valve in this example. The latch type is used for the same reason as in the case of the two-position switching valve 38 described above.

When the output rod 73 or the like is moved to the intermediate position, the pressure is applied to the port a while the port d of the three-position cylinder 70 is pressed. Then, since P1 <P2, the piston 71 is pushed by the piston 71, and the output rod 73 and the frame 74 move to the intermediate position (FIG. 9B).

When the output rod 73 or the like is moved to the open position, pressure is applied to the port c of the three-position cylinder 70 (at this time, whether or not the port a is pressed is optional, and the pressure may be maintained. ). Then, the piston 72 moves forward, and the output rod 73 and the frame 74 move to the open position (FIG. 9C).

When the output rod 73 or the like is moved to the closed position, pressurization to the port a of the three-position cylinder 70 is stopped, exhaust is performed, and pressure is applied to the port d. Then, the piston 72 moves backward, and the output rod 73 and the frame 74 are moved.
Moves to the closed position (FIG. 9A).

When the frame 74 moves to the closed position, as shown in FIG.
7, the roller 80 is pulled rearward by the front side of the frame 74, and the flap valve 4 is closed.

When the frame 74 moves to the intermediate position,
As shown in FIG. 10B, when the flap valve 4 is closed, the roller 80 (80a shown by a two-dot chain line in FIG.
4 can freely move within the frame 74 without being pushed. That is, the stroke of the output rod 73 to the intermediate position and the inner dimension of the frame 74 are determined in such a manner. Therefore, in this state, the flap valve 4 can move without receiving any resistance from the three-position cylinder 70. The control circuit 64 described above is in this state at the time of venting,
The vent valve 12 is opened, and the vent gas 13 is introduced into the pre-vacuum chamber 2. Then, when the venting advances and the vacuum preparatory chamber 2 becomes almost atmospheric pressure, more specifically, in this example, as described above, one step before the atmospheric pressure, the force for opening the flap valve 4 by the valve opening mechanism 44a. However, the flap valve 4 overcomes the force of suctioning the flap valve 4 toward the pre-vacuum chamber 2 by vacuum, and the flap valve 4 automatically opens to the intermediate position (FIG. 10B). At this time, the angle at which the flap valve 4 opens is determined by the
The angle can be limited to a certain angle depending on the angle up to the front side of No. 4. In this example, the angle is set to about 10 degrees as an example.

When the frame 74 moves to the open position, as shown in FIG.
7, the roller 80 is pushed forward by the rear side of the frame 74, and the flap valve 4 is fully opened.

As described above, in this embodiment, the flap valve 4
Is opened from the three-position cylinder 70 to open the intermediate position, and only the flap valve 4 is moved.
The force required for the valve opening mechanism 44a or 44b may be small, and the size thereof can be reduced. Further, the resistance of the piston of the cylinder may fluctuate. However, since the resistance is not affected at all, the condition for opening the flap valve 4 to the intermediate position can be accurately determined.

[0067]

Since the present invention is configured as described above, it has the following effects.

According to the first aspect of the present invention, since the above-described flap valve driving device is provided, the vacuum spare chamber is pressurized at the time of venting, and a large amount of vent gas mixed with an odor is discharged outside the vacuum spare chamber. It can be prevented from blowing out at once. Moreover, since the exhaust cover and the exhaust duct as described above are provided, vent gas containing an unpleasant odor coming out of the flap valve opened at the intermediate position is prevented from leaking into the atmosphere while being forced to the desired one. Can be discharged to a place. As a result, when the flap valve is opened, the unpleasant odor can be prevented from leaking out of the vacuum preparatory chamber into the atmosphere, and furthermore, the unpleasant odor can be prevented from reaching the environment of the worker. In addition, the time for keeping the flap valve at the intermediate position is, for example, about several seconds, which is much shorter than the time that would be required for conventional two-time venting. it can.

According to the second aspect of the present invention, the following additional effects can be obtained. That is, when the vacuum preliminary chamber becomes almost atmospheric pressure at the time of venting, the force by which the valve opening mechanism opens the flap valve exceeds the force with which the flap valve is sucked into the vacuum preliminary chamber, and the flap valve automatically opens to the intermediate position. As a result, the vacuum preparatory chamber is automatically opened to the atmosphere, so that a safety valve is not required, and pressurization of the vacuum preparatory chamber during venting can be reliably prevented. As a result, it is not necessary to use a safety valve as in the conventional example, or to use a safety valve system for the ceiling lid of the pre-vacuum chamber, so that it is possible to prevent a problem of vacuum leakage from the safety valve. In addition, since the ceiling lid can be fixed, the thickness of the ceiling lid can be reduced and the size and weight of the ceiling lid can be reduced.

According to the third aspect of the present invention, the following further effects can be obtained. That is, since the resistance of the piston of the cylinder is not affected when the flap valve is opened to the intermediate position, the force required for the valve opening mechanism can be reduced accordingly, and the size can be reduced. Further, since there is no influence of the resistance of the piston, the condition that the flap valve opens to the intermediate position can be accurately determined.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of the vicinity of a pre-vacuum chamber of a substrate processing apparatus according to the present invention, and corresponds to an EE section in FIG.

FIG. 2 is a diagram showing a main part of an example of a flap valve driving device constituting the present invention.

FIG. 3 is an enlarged perspective view showing a periphery of a flap valve opened to an intermediate position in FIG. 1;

FIG. 4 is a diagram schematically showing a flow of vent gas when a flap valve is at an intermediate position.

FIG. 5 is a diagram illustrating an example of a detector.

FIG. 6 is a view showing another example of the valve opening mechanism.

FIG. 7 is a diagram showing another example of the cylinder control circuit.

FIG. 8 is a perspective view showing a main part of another example of the flap valve driving device constituting the present invention.

FIG. 9 is a diagram illustrating an example of a cylinder control circuit included in the flap valve driving device illustrated in FIG. 8;

FIG. 10 is a view showing the movement of the frame of the flap valve driving device shown in FIG. 8;

FIG. 11 is a schematic plan view showing an example of a conventional substrate processing apparatus.

FIG. 12 is a vertical sectional view taken along line EE in FIG. 11;

[Explanation of symbols]

 2 Pre-vacuum chamber 4 Flap valve 11 Gas inlet 13 Vent gas 20 Substrate 25a, 25b Flap valve drive 92 Exhaust cover 94 Exhaust duct 104 Processing chamber

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/3065 H01L 21/302 B

Claims (3)

[Claims] 1. A processing chamber for processing a substrate using an ion beam or plasma, and a processing chamber provided between the processing chamber and the atmosphere. A vacuum spare chamber where venting is repeated, a flap valve separating the vacuum spare chamber from the atmosphere, and opening and closing the flap valve, and the pressure of the vacuum spare chamber at the time of venting becomes approximately atmospheric pressure. A flap valve driving device that automatically opens the flap valve to an intermediate position between the closed position and the open position when the flap valve is opened, an exhaust cover that covers around the opening of the flap valve that is opened to the intermediate position, An exhaust duct connected to the cover and forcibly exhausting the inside of the exhaust cover. 2. A double-acting cylinder for opening and closing the flap valve, a coupling mechanism for converting a reciprocating linear motion of the double-acting cylinder into an opening and closing motion of the flap valve, and A cylinder control circuit for controlling the piston of the cylinder to two positions corresponding to the closed position and the open position of the flap valve and a free state of the piston, and constantly applying force to the flap valve in the opening direction, When the piston of the double-acting cylinder is in a free state, and the pressure in the vacuum spare chamber is substantially equal to the atmospheric pressure, the flap valve moves its flap valve against the force attracted to the vacuum spare chamber side. A valve opening mechanism that opens to an intermediate position between the closed position and the open position, and controls the cylinder control circuit to free the piston of the double-acting cylinder when the vacuum preliminary chamber is vented. 2. The substrate processing apparatus according to claim 1, further comprising: a control circuit configured to control the introduction of the vent gas into the pre-vacuum chamber. 3. A three-position cylinder for driving the flap valve to a closed position, an open position and an intermediate position between the flap valve and a frame attached to an output rod of the three-position cylinder. A link mechanism that has an engaging portion that is located in the frame body and engages with the frame body, and that converts a reciprocating linear motion of the frame body into an opening and closing motion of the flap valve; A cylinder control circuit for controlling the output rod of the position type cylinder to three positions corresponding to the closed position, the open position and the intermediate position of the flap valve, and constantly applying force to the flap valve in the opening direction, When the output rod of the three-position type cylinder is at the intermediate position and the pressure in the vacuum pre-chamber becomes almost atmospheric pressure, the flap valve is opposed to the force sucked into the vacuum pre-chamber side. In A valve opening mechanism that opens to an intermediate position, and a vent gas is introduced into the vacuum preliminary chamber after the output rod of the three-position cylinder is controlled to an intermediate position by controlling the cylinder control circuit when the vacuum preliminary chamber is vented. The substrate processing apparatus according to claim 1, further comprising: a control circuit configured to perform control.