JP5316180B2 - Pre-aligner device, transport device including the same, and semiconductor manufacturing device - Google Patents

Description

  The present invention relates to a pre-aligner apparatus that adjusts the position of a semiconductor wafer, and more particularly to a mechanism that prevents gas in the atmosphere outside the apparatus from entering the apparatus.

  The pre-aligner device is mainly used in combination with a wafer handling robot in a semiconductor manufacturing apparatus or the like, and is preliminarily provided on the outer periphery of the wafer by gripping (grip) the wafer transferred from the robot and rotating the wafer. This is a device for detecting notches such as notches and orientation flats and aligning them in a predetermined angular direction based on the notches and determining the center position of the wafer itself (centering). The pre-aligner device is a box with a downflow airflow that has passed through a filter in a semiconductor manufacturing process that does not like dust (particles) in recent semiconductor manufacturing devices, that is, a locally cleaned housing (front-end device, etc.) ) Together with the wafer handling robot and installed as a wafer transfer system. A cassette opener (POD opener or FOUP opener) that opens and closes a cassette (FOUP, etc.) containing wafers is provided on the side of the housing, and this opener allows a clean atmosphere outside the housing to enter the housing. The cassettes are opened and closed without any change. Then, the wafer handling robot places the wafer in the cassette on the pre-aligner, and transports the aligned wafer to a processing apparatus installed adjacent to the casing. In the processing apparatus, predetermined processing such as CVD, etching, exposure, and the like is performed. Then, the wafer that has been processed by the processing apparatus is again stored in the cassette by the wafer handling robot.

  Thus, since the pre-aligner carries the wafer into and out of the processing apparatus together with the robot and moves the wafer, frequent operations occur. If the operation occurs, particles are generated from the drive mechanism, and if the particles are placed on the wafer, the semiconductor manufacturing is adversely affected. In order to prevent this, the filter is provided in the housing as described above, and the pre-aligner and robot are present under the clean air flow that has passed through the filter. The particles that have flown are caused to flow to the lower part of the casing, so that the particles do not rest on the wafer. Also, the pre-aligner itself is vacuumed against the external atmosphere by sucking the inside of the machine frame with vacuum exhaust or a fan, etc., so that particles generated by the drive mechanism inside the machine frame of the pre-aligner are It does not scatter to the outside atmosphere and adhere to the wafer.

The configuration of the pre-aligner described above will be described with reference to FIGS. 4, 5, and 6. 4, 5, and 6 are side cross-sectional views showing a conventional pre-aligner driving mechanism.
In FIG. 4, 1 is a pre-aligner device, 2 is a mounting base to which the pre-aligner device is attached, and 3 is an external atmosphere around the pre-aligner device 1. 21 is a machine frame of the pre-aligner, 22 is a motor fixed to the machine frame 21, and 23 is a drive pulley fixed to the rotating shaft of the motor 22. Reference numeral 24 denotes a shaft penetrating into the machine frame 21. The shaft 24 is rotatably supported by a bearing 25 provided on the upper plate of the machine frame 21, and is driven at the lower end by rotating the rotational force of the drive pulley 23 via a timing belt 26. A pulley 27 is provided, and a wafer stage 28 for mounting a wafer 29 is provided on the upper end. The wafer stage 28 is provided with a wafer suction device 30 for vacuum-sucking the wafer 29, and the wafer 29 is configured to rotate simultaneously when the shaft 24 rotates. Reference numeral 31 denotes a sensor unit for detecting the outer periphery of the wafer 29. Reference numeral 32 denotes an exhaust joint for generating a negative pressure inside the machine casing 21 against the external atmosphere 3.

Next, the operation of the conventional pre-aligner driving mechanism will be described.
The wafer 29 requiring alignment is mounted on the wafer stage 28 by a wafer transfer device (wafer handling robot) (not shown). The mounted wafer 29 is sucked onto the wafer stage 28 by the wafer suction device 30 and fixed so that the mounting position does not shift. Next, when an operation command is given to the motor 22 from a pre-aligner control device (not shown), the motor 22 rotates, and the rotational force of the motor 22 is transmitted through the drive pulley 23, the timing belt 26, and the driven pulley 27 to the shaft 24. Is transmitted to. When the shaft 24 rotates, the wafer stage 28 rotates, and the wafer 29 mounted on the wafer stage 28 rotates. The sensor unit 31 detects the position of the outer peripheral portion of the wafer 29 when the wafer 29 rotates by a predetermined amount, the amount of deviation of the center position of the wafer 29 from the reference axis, and a notch or orientation flat provided on the outer peripheral portion of the wafer. Detect the position of the notch. Information on the detected center position shift amount and notch position of the wafer 29 is transmitted to a pre-aligner control device (not shown). The pre-aligner control device processes the above information and notifies the control device of the wafer transfer device (not shown) of the deviation amount. Further, the pre-aligner control device rotates the motor 22 and rotates the notch position of the wafer 29 to a predetermined position. A control device of the wafer transfer device (not shown) instructs the wafer transfer device to operate the drive mechanism of the wafer transfer device, and the wafer transfer device is operated so that the center position of the wafer 29 matches the reference axis of the wafer transfer device hand. The wafer 29 is operated to be received from the wafer stage 28. At this time, before the wafer transfer device (not shown) receives the wafer 29 from the wafer stage 28, the wafer suction device 30 that has sucked the wafer 29 so as not to deviate from the mounting position on the wafer stage 28 is unlocked (non-sucked). State). The wafer alignment operation is performed by the above means.

During these operations, exhaust from an exhaust device such as a vacuum pump (not shown) connected to the exhaust joint 32 causes the inside of the machine casing 21 to be negatively pressured against the external atmosphere 3, and Particles generated by the drive mechanism are prevented from being scattered into the external atmosphere 3 through a gap 35 between the machine casing 21 and the shaft 24.
Further, instead of exhausting from an exhaust device such as a vacuum pump (not shown) connected to the exhaust joint 32, an exhaust fan 33 is provided in the machine frame 21 as shown in FIG. By discharging, the inside of the machine casing 21 is negatively pressured with respect to the external atmosphere 3, and the particles generated by the drive mechanism inside the machine casing 21 may be prevented from scattering into the external atmosphere 3.
Further, as shown in FIG. 6, by providing a magnetic fluid seal 34 concentrically with a gap 35 between the machine frame 21 and the shaft 24, particles generated by a drive mechanism inside the machine frame 21 are caused to occur. In some cases, scattering from the gap 35 is prevented.
In this way, in the conventional pre-aligner device, in order to prevent particles from scattering into the external atmosphere, the inside of the machine frame is negatively pressurized with respect to the external atmosphere by suctioning with a vacuum exhaust or a fan. Or the gap of the shaft rotating part is closed by a magnetic fluid seal (for example, Patent Document 1).
In some cases, the control device of the pre-aligner device and the control device of the wafer transfer device are integrally configured.

JP 2006-245079 A

However, in the conventional pre-aligner apparatus as shown in FIGS. 4, 5, and 6, there is a downflow in the EFEM and the inside of the machine frame 21 of the pre-aligner is in order to suppress particles as described above. Since negative pressure is applied to the external atmosphere 3, the gas in the external atmosphere 3 enters the inside of the machine frame 21 from the gap 35 between the machine frame 21 and the shaft 24, the gap between the members constituting the machine frame 21, and the like. It was inflowing.
However, when the pre-aligner apparatus is used in a process apparatus such as CVD or PVD, the wafer processing gas used in the process is transported to the pre-aligner apparatus with a small amount of wafer transported by the wafer transport. It also remains on the periphery of the wafer 29. During the wafer placement or alignment operation on the pre-aligner, as described above, the residual gas around the wafer 29 enters the inside of the machine frame 21 of the pre-aligner. The residual gas in the periphery of the wafer 29 that penetrates into the machine frame 21 is a wafer processing gas used in the process and is a corrosive gas. Therefore, the wafer is placed on the pre-aligner and aligned once. Even if the amount of penetration into the inside of the pre-aligner is small, if it is continuously operated in the production line, the inside of the pre-aligner will be exposed to corrosive gas over a long period of time. In particular, the timing belt 26, the bearing 25, the electronic components of the sensor unit 31 and the like are deteriorated due to corrosion, and this deterioration causes a failure of the pre-aligner device, and maintenance such as production stoppage or frequent replacement of components is performed. There was a problem of being forced to work. In addition, it is not easy to dispose of the replacement parts inside the pre-aligner apparatus exposed to the corrosive gas, and the disposal cost is high. Also, in the conventional pre-aligner apparatus as shown in FIG. 6, there is a problem with the corrosion resistance of a general magnetic fluid seal, so the pre-aligner apparatus is used in a process apparatus that uses corrosive gas. The magnetic fluid seal 34 is deteriorated by being exposed to the corrosive gas remaining in the periphery of the wafer 29, and the seal effect cannot be obtained when used for a long time in the production line. there were.
Therefore, the present invention has been made in view of such problems, and prevents the particles from scattering from the inside of the pre-aligner apparatus, and also in the environment where a corrosive gas such as CVD or PVD is used. It is an object of the present invention to provide a pre-aligner device that does not allow corrosive gas to enter inside and can obtain stable corrosion resistance performance for an extremely long period of time.

In order to solve the above problem, the present invention is configured as follows.
The present invention includes a wafer stage on which a semiconductor wafer is mounted, a drive unit that rotates the wafer stage, a sensor unit that detects an outer peripheral portion of the semiconductor wafer that is rotated by the drive unit, the drive unit, and the sensor unit. A pre-aligner device that rotates the semiconductor wafer to a desired position in accordance with information on the outer peripheral portion detected by the sensor unit. by well as negative pressurization to the outside atmosphere, the jacket container provided outside of the machine frame, positive pressure and to pulp rear the space between the jacket container and the machine frame relative to the outside atmosphere A liner device was obtained.
In the present invention, a gas introduction joint is provided in the jacket container, and clean air is applied from the gas introduction joint to fill the space between the machine frame and the jacket container. in, and a positive pressure and to pulp rear liner device to the external atmosphere space between the machine frame and the cover fabric container.
In the present invention, a gas introduction fan is provided in the jacket container, and air is supplied to the space between the machine frame and the jacket container by the gas introduction fan, and the machine frame and the jacket container are provided. by filling the space between the, and the positive pressure and to pulp rear liner device to the external atmosphere space between the machine frame and the cover fabric container.
Further, according to the present invention, in the jacket container, a portion where the sensor portion covers a detection shaft portion for detecting the shape of the outer peripheral portion of the semiconductor wafer is made of glass or plastic having transparency and corrosion resistance. has been a Help rear liner apparatus.
Further, according to the present invention, the jacket container is formed so that a bottom portion is opened, and a gas introduction fan is provided on a side surface on the opposite side of the wafer stage across the sensor unit and the driving unit. It was flop rear liner apparatus provided with an exhaust fan at the bottom of the frame.
Further, the present invention has been said pre-aligner apparatus, and a wafer transfer device for placing the semiconductor wafer on the wafer stage, and c Fine conveying system comprising a.
Further, the present invention has a semi-conductor manufacturing apparatus provided with the wafer transfer system.

  According to the present invention, an air flow is formed from the pre-aligner apparatus main body to the wafer side by making the space between the machine frame and the outer casing container more positive than the external atmosphere with clean air. Residual gas in the periphery does not enter the pre-aligner device. Further, since the inside of the machine frame is negatively charged, particles from the internal drive unit do not flow out of the pre-aligner device, and the wafer is not contaminated. In addition, since the corrosive residual gas around the wafer does not enter the pre-aligner, the pre-aligner device can obtain stable corrosion resistance performance over an extremely long period of time, and frequent maintenance work. Is no longer necessary. Moreover, since no corrosive product can be produced, the disposal cost can be reduced.

1 is a side sectional view of a pre-aligner apparatus showing a first embodiment of the present invention. Side sectional view of a pre-aligner apparatus showing a second embodiment of the present invention. Side sectional view of a pre-aligner apparatus showing a third embodiment of the present invention. Side sectional view of a conventional pre-aligner device Side sectional view of another conventional pre-aligner device Side sectional view of another conventional pre-aligner device

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side sectional view of the pre-aligner device of the present invention. The same mechanism as the conventional one is given the same number as FIG. In FIG. 1, 1 is a pre-aligner device, 2 is a mounting base to which the pre-aligner device is attached, and 3 is an external atmosphere around the pre-aligner device 1. 21 is a machine frame of the pre-aligner, 22 is a motor fixed to the machine frame 21, and 23 is a drive pulley fixed to the rotating shaft of the motor 22. Reference numeral 24 denotes a shaft penetrating into the machine frame 21. The shaft 24 is rotatably supported by a bearing 25 provided on the upper plate of the machine frame 21, and is driven at the lower end by rotating the rotational force of the drive pulley 23 via a timing belt 26. A pulley 27 is provided, and a wafer stage 28 for mounting a wafer 29 is provided on the upper end. The wafer stage 28 is provided with a wafer suction device 30 for vacuum-sucking the wafer 29, and is configured such that when the shaft 24 rotates, the wafer 29 rotates simultaneously. Reference numeral 31 denotes a sensor unit that detects the shape of the outer peripheral portion of the rotating wafer 29. Reference numeral 32 denotes an exhaust joint provided in the machine casing 21, which is connected to an exhaust device such as a vacuum pump (not shown) and exhausts the interior of the machine casing 21 to create a negative pressure against the external atmosphere.

Furthermore, in the present invention, the outer casing 11 is provided outside the machine casing 21, and the gas introducing joint 12 is further provided in the outer casing 11. A space 14 is secured by providing a plurality of support columns 13 between the machine casing 21 and the outer casing 11, and the space 14 between the casing and the outer casing is a substantially closed space. However, since the wafer stage 28 passes through the outer casing 11 and is positioned outside the outer casing 11, a gap 15 is formed between the shaft 24 below the wafer stage 28 and the outer casing 11. Further, in the outer casing 11, a portion exposed to the outer surface is made of a material having excellent corrosion resistance. In particular, the detection shaft portion 11 </ b> A for the sensor portion 31 to detect the shape of the outer peripheral portion of the wafer 29 is transparent and corrosion-resistant. It is made of a material such as glass or plastic having a property, so that the external atmosphere 31 does not enter the sensor unit 31.
The machine casing 21 includes the motor 22, the driving pulley 23, the timing belt 26, the driven pulley 27, the wafer suction device 30, the bearing 25, the lower portion of the shaft 24, and the sensor unit 31, and is exhausted as described above. The interior of the machine casing 21 is exhausted to a pressure P3 lower than the pressure P1 of the external atmosphere 3 through the joint 32. The outer casing 11 is formed so as to cover the entire machine casing 21, but only the upper part of the shaft 24 and the wafer stage 28 are exposed to the external atmosphere 3. Then, a gas that does not affect the machine casing 21 and each part included therein is introduced toward the space 14 via the gas introduction joint 12 so that the pressure P2 of the space 14 satisfies P3 <P1 <P2. Maintained.

  Next, the operation of the pre-aligner driving mechanism of the present invention will be described. The operation is basically the same as that of the conventional pre-aligner driving mechanism. The wafer 29 requiring alignment is mounted on the wafer stage 28 by a wafer transfer device (wafer handling robot) (not shown). The mounted wafer 29 is sucked onto the wafer stage 28 by the wafer suction device 30 and fixed so that the mounting position does not shift. Next, when an operation command is given to the motor 22 from a pre-aligner control device (not shown), the motor 22 rotates, and the rotational force of the motor 22 is transmitted through the drive pulley 23, the timing belt 26, and the driven pulley 27 to the shaft 24. Is transmitted to. When the shaft 24 rotates, the wafer stage 28 rotates, and the wafer 29 mounted on the wafer stage 28 rotates. The sensor unit 31 detects the position of the outer peripheral portion of the wafer 29 when the wafer 29 rotates by a predetermined amount, the amount of deviation of the center position of the wafer 29 from the reference axis, and a notch or orientation flat provided on the outer peripheral portion of the wafer. Detect the position of the notch. Information on the detected center position shift amount and notch position of the wafer 29 is transmitted to a pre-aligner control device (not shown). The pre-aligner control device processes the above information and notifies the control device of the wafer transfer device (not shown) of the deviation amount. Further, the pre-aligner control device rotates the motor 22 and rotates the notch position of the wafer 29 to a predetermined position. A control device of the wafer transfer device (not shown) instructs the wafer transfer device to operate the drive mechanism of the wafer transfer device, and the wafer transfer device is operated so that the center position of the wafer 29 coincides with the reference axis of the hand of the wafer transfer device. The wafer 29 is operated to be received from the wafer stage 28. At this time, before the wafer transfer device (not shown) receives the wafer 29 from the wafer stage 28, the wafer suction device 30 that has sucked the wafer 29 so as not to deviate from the mounting position on the wafer stage 28 is unlocked (non-sucked). State). The wafer alignment operation is performed by the above means. In some cases, the control device of the pre-aligner device and the control device of the wafer transfer device are configured integrally.

  In the present invention, during these operations, the inside of the machine casing 21 is made negative pressure by exhausting from an exhaust device such as a vacuum pump (not shown) connected to the exhaust joint 32 and provided in the outer casing 11. Clean air is constantly fed from the gas introduction joint 12 thus filled to fill the space 14 between the machine casing 21 and the outer casing 11, and the space 14 between the casing 21 and the outer casing 11 is continuously filled. Keep positive pressure against the external atmosphere 3. By doing so, an airflow flowing from the pre-aligner main body to the wafer 29 side is formed in the gap 15 between the shaft 24 and the outer casing 11, and the outer casing 11 is formed in the gap between each member constituting the outer casing 11. Since an air flow flowing from the inside to the external atmosphere 3 is formed, the residual gas around the wafer does not enter the pre-aligner. In addition, since the inside of the machine frame 21 of the pre-aligner is negatively applied to the outside thereof, particles from the drive unit inside the pre-aligner do not flow out to the outside atmosphere, and the wafer 29 is contaminated. Absent.

  By adopting such a configuration, the corrosive residual gas around the periphery of the wafer does not enter the pre-aligner, so that the pre-aligner device can obtain stable anti-corrosion performance for a very long time. And no frequent maintenance work is required. In addition, since a corrosive product cannot be produced, the disposal cost of each part can be reduced.

  FIG. 2 is a diagram showing the configuration of the second embodiment. The second embodiment is different from the first embodiment in that clean air is supplied from the gas introduction joint 12 provided in the outer casing 11 as a means for making the inner side of the outer casing 11 positive with respect to the external atmosphere 3. Instead of filling the space 14 between the machine casing 21 and the casing container 11 with a gas introducing fan 16 provided in the casing container 11, and the machine casing 21 and the casing container are provided by the gas introducing fan 16. The space 14 between the machine casing 21 and the outer casing 11 is filled by supplying air to the space 14 between the outer casing 11 and the outer casing 11. Here, the intake port of the gas introduction fan 16 is provided at a location that is clean due to the downflow in the EFEM and does not include the surrounding gas around the wafer. That is, in this embodiment, the gas introduction fan 16 is installed on the side surface of the outer casing 11 on the opposite side of the wafer 29 with the sensor unit 31 and the motor 22 interposed therebetween. With such a configuration, in the first embodiment, an air supply source for supplying air to the gas introduction joint 12 is necessary. However, it is only necessary to supply power to the fan. With such a system configuration, the corrosive residual gas around the wafer does not enter the pre-aligner, and the pre-aligner apparatus can obtain stable corrosion resistance performance for a very long time.

  FIG. 3 is a diagram showing the configuration of the third embodiment. The third embodiment is different from the first and second embodiments in that the space 14 between the machine casing 21 and the outer casing 11 is not a substantially closed space, and the bottom portion of the pre-aligner device 1 is open. This configuration is employed when there is no wraparound of residual gas at the periphery of the wafer on the bottom surface of the pre-aligner apparatus 1. With such a configuration, the configuration of the outer casing 11 can be simplified. In addition, the bottom surface of the pre-aligner device 1 in the space 14 between the machine casing 21 and the outer casing 11 is an opening, and an exhaust fan 33 for negative pressure inside the machine casing 21 is provided in the machine casing 21. Is provided with a gas introduction fan 16 for making the inside of the outer casing 11 positive with respect to the external atmosphere 3 in the outer casing 11, and the inlet of the gas introduction fan 16 is down in the EFEM. By providing it at a location that is clean by the flow, does not wrap around the residual gas around the wafer, and does not take in the exhaust from the exhaust fan 33, in the first and second embodiments, An evacuation device such as a vacuum pump for evacuating from the joint 32 is necessary. However, since it is only necessary to supply power to the fan, the corrosive residue on the periphery of the wafer can be obtained with a simpler system configuration. Prevents the gas from entering into the inside pre-aligner, the pre-aligner apparatus can obtain an extremely long stable corrosion resistance.

DESCRIPTION OF SYMBOLS 1 Pre-aligner apparatus 2 Mounting base 3 External atmosphere 11 Cover container 11A Sensor detection shaft part 12 of a cover container 12 Gas introduction joint 13 Support | pillar 14 Space 15 between a machine frame and a cover container 16 Space | gap 16 between a shaft and a cover container Gas introduction fan 21 Machine frame 22 Motor 23 Drive pulley 24 Shaft 25 Bearing 26 Timing belt 27 Driven pulley 28 Wafer stage 29 Wafer 30 Wafer adsorption device 31 Sensor part 32 Exhaust joint 33 Exhaust fan 34 Magnetic fluid seal 35 Machine frame and Gap arrow with shaft Direction of airflow

Claims (7)

A wafer stage on which a semiconductor wafer is mounted, a motor, a mechanism for transmitting the rotational force of the motor to the wafer stage to rotate the wafer stage, and an outer peripheral portion of the semiconductor wafer rotating with the wafer stage are detected. comprising a sensor unit, and the pre-aligner device for rotating the semiconductor wafer to a desired position in accordance with the outer peripheral portion of the information detected by the sensor unit,
A machine frame that exposes the wafer stage to an external atmosphere and houses the motor, the mechanism, and the sensor unit;
An outer container formed to cover the machine frame along an outer surface of the machine frame;
With
Characterized in that the positive pressure space to the outside atmosphere between as well as negative pressurization to the external atmosphere by sucking the inside of the machine casing, and the casing container before and Symbol machine frame Pre-aligner device. The outer casing container is provided with a gas introduction joint, and clean air is applied from the gas introduction joint to fill the space between the machine casing and the outer casing container, The pre-aligner device according to claim 1, wherein a space between the outer casing and the outer container is set to a positive pressure.
  A gas introduction fan is provided in the jacket container, and air is supplied to the space between the machine casing and the casing container by the gas introduction fan to fill the space between the machine casing and the casing container. The pre-aligner apparatus according to claim 1, wherein a space between the machine casing and the outer casing is set to a positive pressure with respect to the external atmosphere.   In the outer container, a portion of the sensor portion that covers a portion of the detection shaft for detecting the shape of the outer peripheral portion of the semiconductor wafer is made of glass or plastic having transparency and corrosion resistance. The pre-aligner device according to claim 1. The jacket container is formed so that a bottom portion is opened, and a gas introduction fan is provided on the opposite side surface of the wafer stage across the sensor unit and the motor ,
2. The pre-aligner apparatus according to claim 1, wherein an exhaust fan is provided at a bottom portion of the machine casing.   A wafer transfer system comprising: the pre-aligner device according to claim 1; and a wafer transfer device for placing the semiconductor wafer on the wafer stage.   A semiconductor manufacturing apparatus comprising the wafer transfer system according to claim 6.

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