JP3078834B2 - Drive - Google Patents

Description

Description: Object of the Invention (Industrial Application Field) The present invention relates to a driving device, and particularly to a driving device suitable for a device that dislikes dust and needs to perform chemical treatment or the like. About.

(Prior Art) As a device that dislikes dust and needs to perform chemical treatment, for example, there is a cleaning device in a semiconductor wafer manufacturing device.

The cleaning device in this semiconductor wafer manufacturing apparatus performs the cleaning process in a dust-free clean atmosphere in consideration of the influence on the semiconductor wafer. In addition, the semiconductor wafer is treated with ammonia, water, hydrofluoric acid, etc. Cleaning process.

Therefore, the conventional cleaning apparatus is provided with a plurality of processing tanks such as an ammonia processing tank, a water washing processing tank, a hydrofluoric acid processing tank, and the like. It was intended to be transported and supplied.

(Problems to be Solved by the Invention) In the above-described cleaning apparatus in the conventional semiconductor wafer manufacturing apparatus, a driving device is used for a transfer device or a boat for transferring a semiconductor wafer to each processing tank. Is a source of dust that generates dust during operation, and the dust generated by this driving device contaminates the clean atmosphere. There is a problem that the product yield of the wafer may be reduced.

Further, the cleaning device uses ammonia for the cleaning process as described above, and there is a problem that if the ammonia enters the driving device, the driving device is corroded.

However, since the driving device is connected to the movable portion, it cannot be completely hermetically sealed.

Therefore, the present invention allows a mechanical gap between the inside and the outside of the driving device serving as a dust source, but does not allow dust to leak from the inside of the driving device to the outside, and furthermore, the atmosphere outside the driving device is reduced. An object of the present invention is to provide a drive device that does not enter the drive device and corrode the inside of the drive device.

[Structure of the Invention] (Means for Solving the Problems) The drive device according to the invention according to claim (1), includes an inner cover that defines a first space, and an open end, and covers the inner cover. A movable cover that defines a second space between the inner cover and a drive unit that is disposed at least partially in the first space and that moves the movable cover relative to the inner cover in the axial direction; An outer cover that covers the inner cover and the movable cover over a moving range of an open end of the movable cover, and defines a third space between the inner cover and the movable cover; And a discharge means for maintaining the third space in a negative pressure state.

According to a second aspect of the present invention, in the driving device according to the first aspect of the present invention, there is provided a sealing device for substantially isolating the second space and the third space; An air introduction hole that enables air to be introduced into the second space according to a change in volume of the second space caused by movement of the movable cover.

A driving device according to a third aspect of the present invention is the driving device according to the first or second aspect, further comprising a sensor that detects a chemical liquid atmosphere exhausted by the exhaust unit. The air supply unit and the exhaust unit are controlled according to a chemical solution atmosphere state detected by the sensor.

The driving device according to the invention according to claim (4), comprising: a driving unit; an inner cover that surrounds the periphery of the driving unit; and a movable cover that covers the outside of the inner cover. A drive unit; an air supply unit for maintaining the inside of the inner cover at a positive pressure; and an exhaust unit for maintaining a negative pressure between the inner cover and the movable cover.

(Operation) In the drive device according to the invention described in claim (1), the inside of the inner cover that covers the drive device, that is, the first space is pressurized by the air supply means to maintain a positive pressure state. The inside of the third space, which is the space between the outer cover and the outer cover and between the movable cover and the outer cover, is evacuated by the exhaust means and maintained in a negative pressure state. Due to the pressure difference inside, the atmosphere in the first space always tries to escape to the third space side. Therefore, dust and the like generated in the first space can be forcibly flowed into the third space and exhausted by the exhaust means, so that influence on the external atmosphere can be prevented.

Further, the external atmosphere that has entered the third space is also exhausted by the exhaust means, and the first space is maintained at a positive pressure atmosphere by the air supply means, thereby preventing the external atmosphere from entering the first space. Will be done. Therefore, even when the external atmosphere contains corrosive gas, etc.
The atmosphere does not flow into the first space and does not affect the drive unit disposed in the first space such as corrosion.

In the driving device according to the invention described in claim (2), the second space and the third space are separated by the sealing means, and the second space and the third space correspond to the volume change in the second space caused by the movement of the movable cover. An air introduction hole is provided to allow the introduction of air into the two spaces. Therefore, it is possible to prevent a situation in which the inside of the second space is in a sealed state and the movable cover is moved by the driving unit, thereby causing a pumping action and sucking gas or the like.

The drive device according to the invention described in claim (3) detects a chemical solution or the like contained as vapor in the atmosphere exhausted by the exhaust unit with a sensor, and controls the air supply unit and the exhaust unit based on the state. Therefore, by appropriately controlling the air supply means and the exhaust means in accordance with the state of the atmosphere in the outer peripheral cover, the vapor of the chemical solution contained in the external atmosphere affects the drive unit and the like in the inner cover, Conversely, it is possible to reliably prevent the atmosphere in the inner cover from affecting the outside.

According to a fourth aspect of the present invention, in the drive device, the inside of the inner cover surrounding the drive section is pressurized by the air supply means to maintain a positive pressure state, and the inner cover and the movable cover for covering the outside thereof. The space between them is exhausted by the exhaust means to maintain a negative pressure state. Therefore, due to the pressure inside the inner cover and the pressure difference in the space between the inner cover and the movable cover, the atmosphere inside the inner cover always tries to escape between the inner cover and the movable cover. Moreover, dust and the like generated in the driving unit and flowing between the inner cover and the movable cover are forcibly exhausted by the exhaust unit. Therefore, even if the external atmosphere may enter the inside of the movable cover, it is possible to prevent the external atmosphere from entering the inner cover, and to prevent the external atmosphere having corrosiveness or the like from adversely affecting the drive unit.
In addition, since dust and the like generated in the driving unit in the inner cover and flowing into the movable cover are forcibly exhausted by the exhaust means, such dust and the like may flow out to the external atmosphere and adversely affect the surroundings. Can also be prevented.

(Example) Hereinafter, an example in which the seal mechanism of the driving device of the present invention is applied to a cleaning device in a semiconductor wafer manufacturing apparatus will be described.
This will be described with reference to the drawings.

In FIG. 1, the semiconductor wafer cleaning apparatus of the present embodiment is configured by combining three cleaning processing units 10, 12, and 14. Further, a loader 16 for a wafer to be processed is connected to the processing unit 10 on the loading side, and an unloader 18 for the processed wafer is connected to the processing unit 14 on the unloading side. Processing unit 12,
Underwater loader 20 included in any of the three units between 14
Are arranged. The arrangement order may be changed. In this example, the setting is made in accordance with a predetermined cleaning processing program.

The carry-in side cleaning processing unit 10 has a rotary transfer arm 24 for transferring the semiconductor wafer 22 at the center position, and two cleaning processing tanks around the front of the loader 16 and the left side of the rotary transfer arm 24 around the arm. 26 and 28 are arranged. In this embodiment, the cleaning tank 26 is used as a chemical processing tank for performing ammonia treatment, and the cleaning tank 28 is used as a quick dump rinse (QDR) processing tank for performing water washing.

The central cleaning processing unit 12 has the underwater loaders 20 positioned on the left and right sides around the rotary transfer arm 24 disposed at the center position, and two cleaning processing tanks 30 and 32 at front and rear positions therebetween.
Is arranged. In this embodiment, the cleaning tank
Numeral 30 is used as a chemical treatment tank for performing hydrofluoric acid treatment, and cleaning treatment tank 32 is used as a water overflow treatment tank.

The cleaning processing unit 14 on the unloading side includes a cleaning processing tank 34 on the front side of the unloader 18 around the rotary transfer arm 24 disposed at the center position, and a drying processing tank 34 on the right side of the rotary transfer arm 24. 36 are arranged. In the present embodiment, the cleaning treatment tank 34 is used as a water-washing final rinse tank.

As shown in FIG. 4, each of the upper cleaning processing tanks 26, 28, 30, 32, 34, the underwater loader 20 and the drying processing tank 36 have a case 40 having an opening 38 for carrying in / out the semiconductor wafer 22.
It is in a state of being arranged inside. And the opening 38
In addition, a shutter 44 for opening and closing the opening 38 is provided, and an air outlet (not shown) is provided above the opening in the case 40, and the case 40 is provided with an air curtain blown from the shutter 44 and the air outlet. The atmosphere between the inside and outside is cut off. In this case, air is sucked from the lower part of the case 40, and the inside of the case 40 is set to a pressure slightly lower than the atmospheric pressure, so that the atmosphere in the case 40 is adjusted so as not to leak outside.

As shown in FIG. 2, the loader 16 aligned the orientation flat of the semiconductor wafers 22 by using a so-called orientation flat aligning mechanism 49 for each of the 25 semiconductor wafers 22 placed on two carriers 48. Later, two careers
The semiconductor wafer 22 on 48 is pushed upward by a push-up rod 51, and the push-up rods 51 are brought close to each other. In this state, only the 50 semiconductor wafers 22 are moved by the rotary transfer arm 24 on the loading side. I'm trying to scoop. The unloader 18 has a mechanism similar to that of the loader 16, and the processing is performed in the reverse order of the loader 16.

As shown in FIG. 3, the rotary transfer arm 24 has a wafer fork 52 for mounting the semiconductor wafer 22 at the tip of a multi-joint arm body 50 that is horizontally rotatable and expandable and contractible. , Only 50 semiconductor wafers 22 are placed without the carrier 48, and the loader 16 and the cleaning tanks 26, 28, 30, 3
2, 34, the semiconductor wafer 22 is transferred between the underwater loader 20, the drying tank 36, and the unloader 18.

Specifically, the wafer fork 52 has two parallel support rods 54 having a large number of support grooves for placing and positioning the semiconductor wafer 22 movably in a horizontal direction, and is provided between the loader 16 and the unloader 18. In this configuration, the semiconductor wafer 22 is received from the push-up rod 51 which moves up and down between the two support rods 54, or the semiconductor wafer 22 is delivered to the push-up rod 51. Vessels 26, 28, 3
0, 32, 34 and the drying processing tank 36, a wafer storage boat 56 provided for storing an object to be processed is moved up and down to move the semiconductor wafer 22 from the boat 56 dedicated to each tank. Or the semiconductor wafer 22 is transferred to the boat 56.

The boat 56 dedicated to each tank has three parallel support rods 58 having a large number of support grooves for mounting and positioning the semiconductor wafer 22, and is moved up and down by the arm 60 as described above as shown in FIG. Supported as possible. These three support rods 58
The rotary transfer arm 24 is provided at a position where it does not interfere with the two support rods 54 of the wafer fork 52 in the vertical direction, and is disposed along the outer shape of the semiconductor wafer 22. Also,
The boat 56 directly mounts and positions the semiconductor wafer 22, and does not use the carrier 48. Then, the semiconductor wafer 22 is placed on the wafer fork 52 of the rotary transfer arm 24, and with the wafer fork 52 inserted into each tank through the opening 38, the arm 60 is extended and the boat is extended.
Raise 56 and the semiconductor wafer on wafer fork 52
22 will be placed on the boat 56. Conversely, boat
With the semiconductor wafer 22 placed on the 56, the boat 56 is raised, and the wafer fork 52 of the rotary transfer arm 24 is moved below the boat 56.
When the boat 56 is lowered and the boat 56 is lowered, the semiconductor wafer 22 on the boat 56 is placed on the wafer fork 52 of the rotary transfer arm 24.

Further, the arm 60 supporting the boat 56 is a driving source that moves up and down, is a portion that causes dust, and is provided in a tank that handles chemicals. The seal mechanism seals to prevent dust from leaking to the outside, and also prevents the chemical atmosphere in the tank from entering the arm 60 and corroding.

Specifically, as shown in FIG. 5, the arm 60 includes a fixed side portion 62 and a movable side portion 64. By moving the movable side portion 64 up and down with respect to the fixed side portion 62, Movable side
An arm body 66 for supporting a boat 56 provided at the top of the boat 64 is moved up and down.

Next, details of the driving device will be described with reference to FIG.

The fixed side portion 62 seals the motor 72 in a housing 70 having a support base 68 on the upper surface, and a screw shaft 74 connected to the motor 72 stands on the support base 68. Around the screw shaft 74, three guide shafts 76 are arranged in parallel at equal intervals.
The other ends of the screw shaft 74 and the guide shaft 76 are supported by a fixed plate 78.

The movable side portion 64 includes a nut 80 screwed to the screw shaft 74, a first movable plate 82 integrated with the nut 80, and movably fitted to the screw shaft 74 and the guide shaft 76. , One end of which is attached to the first movable plate 82 and the other end of which is slidable through the fixed plate 78 at equal intervals.
The slide shaft 84 includes a second movable plate 86 that supports the other end of the slide shaft 84 that penetrates the fixed plate 78, and is vertically movable along the screw shaft 74 and the guide shaft 76. I have. Further, the arm body 66 is placed on the second movable plate 86.
Can be attached.

Then, on the support base 68 of the fixed side portion 62, a cylindrical inner cover 88 for covering the screw shaft 74, the guide shaft 76, the slide shaft 84, etc., which is a vertical drive portion, that is, a drive portion, is attached, and the movable side portion A cylindrical outer cover 90, that is, a movable cover that covers the outside of the inner cover 88 is attached to the second movable plate 86 side of the driven portion 64, ie, the second movable plate 86 side. Further, an outer cover 92 that further covers the outer periphery cover 90 is attached to the inner cover 88, and these inner cover 88 and outer cover 90 are attached.
The outer cover 92 and the outer cover 92 are each provided with a gap so as to form a triple cover. The upper end of the inner cover 88 is
It is sealed by a sealing plate 94 arranged on the fixed plate 78. Further, the space between the sealing plate 94 and the slide shaft 84 and the space between the sealing plate 94 and the outer peripheral cover 90 are sealed with a sealing material 96 as sealing means.

Further, a pressurizing device 98 as an air supply means for pressurizing the inside of the inner cover 88 and maintaining the inside of the inner cover as a first space in a positive pressure state is connected to the inner cover 88. The pressurizing device 98 is for preventing a gas such as ammonia from entering the inner cover 88 and corroding the internal mechanism. In this embodiment, an inert gas such as a nitrogen (N ₂ ) gas is used. From the supporting base 68 into the inner cover 88. Therefore, invasion of gas such as ammonia into the inner cover 88 is prevented by this positive pressure atmosphere.

Further, an exhaust device 100 as an exhaust means is connected to a lower side between the inner cover 88 and the outer cover 92, and the outer cover 9
The third space is evacuated between the inner cover 88 and the outer cover 90 and the outer cover 92. In this way, the exhaust is performed because the gas such as ammonia or dust entering from the upper end side of the outer cover 92 is covered by the outer cover.
In order to prevent the intrusion between the inner cover 88 and the outer cover 90, that is, the second space, even if the inner cover 90 and the outer cover 92 are intruded.
Even if it intrudes into the space 90, it is discharged by the exhaust device 100. The use of the exhaust device 100 can sufficiently cope with the above-described covers even if the covers have some gas permeability.

Thus, the inside of the inner cover 88 covering the drive unit is
Pressurize at 98 to maintain a positive pressure state, and exhaust the inside of the outer cover 90 that covers the outside of the inner cover 88 with the exhaust device 100 to maintain a negative pressure state, so that the pressure inside the inner cover 88 is maintained. ,
Due to the pressure difference in the outer cover 90, the atmosphere in the inner cover 88 always tries to escape to the inside of the outer cover 90. For example, the dust generated in the inner cover 88 is forced to flow into the outer peripheral cover 90 to discharge the dust. On the other hand, even if outside air enters the outer cover 90, the air is exhausted and the inner cover 88 cannot enter.

Even if the atmosphere in the inner cover 88 escapes to the outer cover 90 side, since the inside of the outer cover 90 is exhausted by the exhaust device 100, it does not leak to the outside of the outer cover 90, and dust and the like Never go outside. In this case, the outside air that has entered the outer peripheral cover 90 also
Since it is discharged by zero, intrusion into the inner cover 88 is further prevented.

Further, in the present embodiment, a sensor (not shown) for detecting the state of the chemical solution atmosphere at the time of exhaustion by the exhaust device 100
Is provided to detect the internal state, and in accordance with the state, the pressurizing device 98 and the exhaust device 100 are controlled to maintain the optimal state.

Note that, between the sealing plate 94 and the second movable plate 86, the inside is sealed to prevent a pumping action from occurring during operation of the arm 60 to suck ammonia gas or the like. , An air introduction hole 102 for allowing a small amount of air to be introduced, that is, a pressure adjusting means.

In the above embodiment, the case where 50 semiconductor wafers 22 placed on two carriers 48 are processed at one time has been described. However, the present invention is not limited to this example, and 25 semiconductor wafers 22 on one carrier 48 may be processed. 22 may be processed at once.

Although the three processing units 10, 12, and 14 are combined, the number of combinations can be arbitrarily changed.

Furthermore, in the above embodiment, the example in which the seal mechanism of the present invention is applied to the arm 60 that moves the boat of each processing tank up and down has been described. It is possible to apply a sealing mechanism.

[Effects of the Invention] As described above, the driving device according to the invention described in claim (1) has an inner cover that covers the driving device, that is, the first device.
The space is pressurized by an air supply means to maintain a positive pressure state, and a third space which is a space between the inner cover and the outer cover and between the movable cover and the outer peripheral cover is exhausted by the exhaust means. To maintain the pressure in the first space,
Due to the pressure difference in the third space, the atmosphere in the first space always tries to escape to the third space side. Therefore, dust and the like generated in the first space can be forcibly flowed into the third space and exhausted by the exhaust means, so that influence on the external atmosphere can be prevented.

Further, the external atmosphere that has entered the third space is also exhausted by the exhaust means, and the first space is maintained at a positive pressure atmosphere by the air supply means, thereby preventing the external atmosphere from entering the first space. Will be done. Therefore, even when the external atmosphere contains corrosive gas, etc.
The atmosphere does not flow into the first space and does not affect the drive unit disposed in the first space such as corrosion.

In the driving device according to the invention described in claim (2), the second space and the third space are separated by the sealing means, and the second space and the third space correspond to the volume change in the second space caused by the movement of the movable cover. An air introduction hole is provided to allow the introduction of air into the two spaces. Therefore, it is possible to prevent a situation in which the inside of the second space is in a sealed state and the movable cover is moved by the driving unit, thereby causing a pumping action and sucking gas or the like.

The drive device according to the invention described in claim (3) detects a chemical solution or the like contained as vapor in the atmosphere exhausted by the exhaust unit with a sensor, and controls the air supply unit and the exhaust unit based on the state. Therefore, by appropriately controlling the air supply means and the exhaust means in accordance with the state of the atmosphere in the outer peripheral cover, the vapor of the chemical solution contained in the external atmosphere affects the drive unit and the like in the inner cover, Conversely, it is possible to reliably prevent the atmosphere in the inner cover from affecting the outside.

According to a fourth aspect of the present invention, in the drive device, the inside of the inner cover surrounding the drive section is pressurized by the air supply means to maintain a positive pressure state, and the inner cover and the movable cover for covering the outside thereof. The space between them is exhausted by the exhaust means to maintain a negative pressure state. Therefore, due to the pressure inside the inner cover and the pressure difference in the space between the inner cover and the movable cover, the atmosphere inside the inner cover always tries to escape between the inner cover and the movable cover. Moreover, dust and the like generated in the driving unit and flowing between the inner cover and the movable cover are forcibly exhausted by the exhaust unit. Therefore, even if the external atmosphere may enter the inside of the movable cover, it is possible to prevent the external atmosphere from entering the inner cover, and to prevent the external atmosphere having corrosiveness or the like from adversely affecting the drive unit.
In addition, since dust and the like generated in the driving unit in the inner cover and flowing into the movable cover are forcibly exhausted by the exhaust means, such dust and the like may flow out to the external atmosphere and adversely affect the surroundings. Can also be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing the overall configuration of a cleaning apparatus according to one embodiment of the present invention, FIG. 2 is a plan view showing a loader portion in FIG. 1, and FIG. 3 is a process on the loading side in FIG. FIG. 4 is an enlarged view showing the unit, FIG. 4 is a perspective view showing the state of each washing tank, submerged loader and drying tank, FIG. 5 is a side view showing the state of the arm and boat, and FIG. FIG. 7 is a plan view showing the state of each shaft. 60 ... arm, 66 ... arm body, 74 ... screw shaft, 76 ... guide shaft, 88 ... inner cover, 90 ... outer cover, 92 ... outer cover, 98 ... pressurizing device, 100 ... ... Exhaust device.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/304 H01L 21/68

Claims (4)

(57) [Claims] 1. An inner cover defining a first space, a movable cover having an open end, covering the inner cover, and defining a second space between the inner cover and at least a part of the movable cover. A drive unit disposed in one space and configured to move the movable cover in the axial direction with respect to the inner cover; and a cover that covers the inner cover and the movable cover over a moving range of an open end of the movable cover. An outer cover that defines a third space between the cover and the movable cover; an air supply unit that maintains the first space in a positive pressure state; an exhaust unit that maintains the third space in a negative pressure state; A driving device comprising: 2. The driving device according to claim 1, wherein a sealing means for substantially isolating the second space and the third space, and the second cover caused by movement of the movable cover relative to the inner cover. A driving device, further comprising: an air introduction hole that enables air to be introduced into the second space according to a change in volume of the space. 3. The driving device according to claim 1, further comprising a sensor for detecting a chemical solution atmosphere state exhausted by the exhaust means, wherein the chemical solution atmosphere state detected by the sensor is provided. In response to,
A driving device for controlling the air supply means and the exhaust means. 4. A driving part, comprising: an inner cover surrounding the periphery of the driving part; a movable cover covering the outside of the inner cover; a driven part driven by the driving part; A driving device comprising: an air supply unit that maintains a pressure; and an exhaust unit that maintains a negative pressure between the inner cover and the movable cover.