JP2013212920A - Conveying arm, conveying device, and conveying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveying arm, a conveying device, and a conveying method for conveying a substrate while controlling charging by metal contamination and static electricity.SOLUTION: A conveying arm 1 of a substrate 11 includes: a holding part 12, consisting of an insulator, that contacts with and holds the substrate 11; a metal part 13, consisting of a conductor, that is grounded; and a conductive coating 14, consisting of a conductor, that contacts with the substrate 11 and the metal part 13. Moreover, a conductive part 14 is located between the substrate 11 and the grounded part 13 and is fixed by the grounded part 13.

Description

  The present invention relates to a transport arm, a transport apparatus, and a transport method for transporting a substrate while removing the charge of the substrate due to static electricity generated by contact between the substrate and the transport arm.

  Conventionally, an aluminum alloy, ceramics, stainless steel, or the like is used for a transfer arm of a substrate such as a silicon wafer (see, for example, Patent Document 1).

  When the substrate to be transferred is a silicon wafer on which a semiconductor element is formed later, when a metal comes into contact with the substrate, the metal component moves to the substrate, and the characteristics of the semiconductor element may be deteriorated by the metal component. Such a phenomenon is called metal contamination.

  Here, in this specification, the transport arm includes a holding unit that contacts and holds the substrate and a support unit that supports the holding unit.

  Now, in order to reduce the above-mentioned metal contamination, it has been performed to coat the surface of the holding portion that contacts the substrate with chromium or the like. However, if the number of times of conveyance overlaps, the coating may be worn, and the effect of reducing metal contamination may deteriorate and become a problem. In addition, the coating is costly, and it is necessary to periodically repeat the coating in order to maintain the effect of reducing metal contamination by the coating, which may be a problem.

  Therefore, replacement of the holding portion in contact with the above-described substrate with a nonmetal such as a fluorine-based resin has been performed.

Japanese Patent Laid-Open No. 7-106400 (published on April 21, 1995)

  The transfer of the substrate by the transfer arm is performed by causing the holding portion to suck the substrate, moving the support portion to a desired position, and releasing the suction of the substrate.

  6A and 6B are cross-sectional views showing a conventional transfer arm, in which FIG. 6A is a top view thereof, and FIG. 6B is a cross-sectional view taken along line AA of FIG. FIG. 6 shows a situation where the transfer arm 3 is transferring the substrate 31.

  The substrate 31 is held by the holding unit 32. The holding part 32 is supported by the support part 35. The substrate 31 is sucked and held by the holding unit 32 by suction from an air suction hole provided inside the holding unit 32.

  Here, when the holding unit 32 is made of a non-metal, the substrate 31 may be charged with static electricity due to the contact between the holding unit 32 and the substrate 31 due to the adsorption and the peeling due to the desorption between them. In transporting the substrate 31 by the transport arm 3 in which the holding unit 32 is non-metallic, it becomes a problem to eliminate such charge.

  If both the holding portion 32 and the support portion 35 are metal, the static electricity of the holding portion 32 escapes to the ground through the support portion 35 that is normally grounded, so that the above-described charging does not occur.

  One method of performing the above-described static elimination is a method using an ionizer. However, because there is a need for an additional space for installing the ionizer, and it is necessary to consider the adverse effects of the air flow generated by the ionizer other than the charge removal, there are cases where the use of ionization with the ionizer is limited. .

  As another method of performing the above-described static elimination, there is a method of bringing a grounded metal part into contact with a charged substrate. However, from the viewpoint of preventing the above-described metal contamination, there are cases where the method in which a grounded metal or the like is brought into direct contact with the substrate can be used.

  In view of the above problems, an object of the present invention is to provide a transport arm, a transport apparatus, and a transport method that can neutralize the charge of a substrate while preventing the occurrence of metal contamination on the substrate.

  In order to achieve the above object, a transfer arm according to the present invention is a transfer arm for a substrate, which is in contact with the substrate and holds the substrate. And a conductive portion made of a conductor in contact with the substrate and the ground portion.

  Generally, a metal member is used as the grounding portion. Here, when the substrate to be transported is a silicon wafer on which a semiconductor element is formed later, when a metal comes into contact with the substrate, the metal component moves to the substrate, and the characteristics of the semiconductor element deteriorate due to the metal component. There is. Such a deterioration phenomenon is called a metal contamination phenomenon.

  According to the above configuration, by bringing the substrate held by the holding unit into contact with the conductive unit, the substrate and the grounded grounded unit are electrically connected via the conductive unit. It is grounded and the substrate is discharged. That is, it is possible to remove electricity while keeping the substrate and the grounding portion in non-contact and suppressing the occurrence of metal contamination.

  Therefore, while suppressing the occurrence of metal contamination, it is possible to prevent the substrate from sticking to the holding portion due to charging, and to reduce troubles during transportation.

  The conductive portion is preferably positioned between the substrate and the ground portion and fixed by the ground portion.

  According to the above configuration, since the conductive portion is fixed to the ground portion, the contact state between the substrate and the conductive portion can be stabilized, and the substrate can be stably discharged.

  The conductive part is preferably a coating made of a conductive material applied to a part of the grounding part.

  According to the said structure, an electroconductive part is realizable by the electroconductive coating given to a part of grounding part.

  Moreover, it is preferable that the conveyance arm which concerns on this invention is further provided with the support part which fixes the said holding | maintenance part, and the said earthing | grounding part is being fixed to the said support part.

  According to the above configuration, the holding portion is fixed by the support portion, and the relative position of the holding portion with respect to the support portion is stabilized. Further, the grounding part is fixed by the support part, and the relative position of the grounding part with respect to the support part is stabilized. Therefore, the relative positions of the holding part and the grounding part can be stabilized.

  Moreover, it is preferable that the said grounding part is a fixing member which fixes the said holding | maintenance part to the said support part.

  According to the said structure, since a grounding part is a fixing member, a holding | maintenance part can be fixed more firmly to a support part, and the relative position of the holding | maintenance part with respect to a support part can be stabilized more.

  Moreover, it is preferable that a part or all of the conductive part is provided inside the holding part.

  According to the said structure, the contact position of an electroconductive part and a holding | maintenance part is fixed. Therefore, it is not necessary to move the conductive portion so as to maintain the contact state with the substrate in accordance with the conveyance of the substrate held by the holding portion.

  Further, it is preferable that the conductive portion is in contact with the holding portion.

  According to the above configuration, the relative positional relationship between the conductive portion and the holding portion is fixed. Therefore, it is not necessary to move the conductive portion so as to maintain the contact state with the substrate in accordance with the conveyance of the substrate held by the holding portion.

  Moreover, it is preferable that there are a plurality of sets of the grounding portion and the conductive portion.

  According to the above configuration, since there are a plurality of sets of the grounding portion and the conductive portion, the number of paths through which charges are released from the substrate to the ground increases, and the static elimination performance can be improved.

  Moreover, the transfer apparatus according to the present invention is characterized by using the transfer arm.

  According to the above configuration, in the transfer process using the transfer device of the present invention, by using the transfer arm, it is possible to prevent the substrate from sticking to the holding portion due to charging while suppressing the occurrence of metal contamination. The failure rate can be reduced by reducing the trouble.

  In addition, the transport method according to the present invention is in contact with the substrate and holds the substrate, and is made of an insulator, and is grounded. The grounding portion is made of a conductor, and contacts the substrate and the ground portion. A transport method for transporting the substrate using a transport arm including a conductive portion made of a conductor, wherein the holding step of holding the substrate on the holding portion and the substrate and the conductive portion are brought into contact with each other to eliminate static electricity. And a charge eliminating step.

  According to the above configuration, in the transfer process using the transfer method of the present invention, the substrate is held on the holding unit in the holding step, and the substrate and the conductive unit are brought into contact with each other in the static elimination step to remove the charge, thereby the substrate and the grounding unit. Is kept in a non-contact state and the generation of metal contamination can be suppressed, and static electricity can be removed.

  Therefore, the defect rate can be reduced by suppressing the occurrence of metal contamination, preventing the substrate from sticking to the holding portion due to charging, and reducing troubles during transportation.

  As described above, the transfer arm according to the present invention is in contact with the substrate and holds the substrate, the holding unit made of an insulator, the grounded grounding unit made of a conductor, the substrate, and the ground And a conductive portion made of a conductive material in contact with the portion.

  Therefore, while suppressing the occurrence of metal contamination, it is possible to prevent the substrate from sticking to the holding portion due to charging and to reduce troubles during transportation.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiment of the conveyance arm which concerns on this invention is shown, (a) is the top view, (b) is sectional drawing of the AA cross section of (a). It is a conceptual diagram which shows embodiment of the conveying apparatus which concerns on this invention. FIG. 2 shows an embodiment in which the positions of the metal component and the conductive coating in FIG. 1 are changed, (a) is a top view thereof, and (b) is a cross-sectional view of the AA cross section of (a). FIG. 2 shows an embodiment in which the number of metal parts and conductive coatings in FIG. 1 are changed, (a) is a top view thereof, and (b) is a cross-sectional view taken along the line AA of (a). FIG. 2 shows an embodiment in which the areas of the metal part and the conductive coating in FIG. 1 are changed, in which (a) is a top view and (b) is a cross-sectional view of the AA cross section of (a). It is sectional drawing which shows the conveyance arm of a prior art.

[Embodiment 1]
An embodiment of the present invention will be described with reference to FIG.

<Basic configuration>
First, based on FIG. 1, the structure of the conveyance arm 1 which is one Embodiment of this invention is demonstrated.

  1A and 1B are diagrams illustrating a schematic configuration of a transfer arm 1 according to an embodiment of the present invention, in which FIG. 1A is a top view thereof and FIG. 1B is a cross-sectional view taken along a line AA in FIG.

  FIGS. 1A and 1B show a state in which the transfer arm 1 is transferring the substrate 11.

  The substrate 11 is held by the holding unit 12. The holding unit 12 is connected to the support unit 15 by four metal parts (grounding units) 13. The metal component 13 is provided with a conductive coating (conductive portion) 14. The conductive coating 14 is in contact with the substrate 11.

  In addition, as a material of the conductive coating 14, a conductive polymer, ITO (transparent conductive film, indium dope tin oxide), FTO (fluorine dope tin oxide) can be mentioned. By using the above-mentioned material as the material of the conductive coating 14, the metal component of the metal component 13 can be prevented from moving to the substrate 11 and metal contamination can be prevented. Further, by using the above-described materials as the material of the conductive coating 14, metal contamination does not occur due to the contact of the conductive coating 14 with the substrate 11.

  In FIG. 1, the holding unit 12 is connected to the support unit 15 by the metal part 13, but may be connected using an adhesive or the like, or may be integrated with the support unit 15. In this case, the holding part 12 and the support part 15 do not need to be connected by the metal part 13.

  In addition, the metal component 13 needs to be grounded in order to remove electricity from the substrate 11 described later. As for the grounding method, when the support portion 15 is made of a metal, it may be grounded through the support portion 15 or may be electrically connected to another grounded member or wiring (not shown). good.

  Here, the holding part 12 has a hole in the center. When the substrate 11 is held by the holding unit 12, the holding unit 12 is brought into contact with the substrate 11, and the above-described hole is set to a low pressure or a vacuum using a vacuum pump or the like, and the substrate 11 is adsorbed to the holding unit 12.

  In addition, in order to maintain a low pressure or a vacuum state, a member such as packing may be disposed as an additional member in the vicinity of the above-described hole. Further, in order to stably hold the substrate 11, a member such as a cushion may be disposed as an additional member on the suction surface of the holding unit 12 on which the substrate 11 is sucked.

  As described above, the transfer arm 1 is moved while the substrate 11 is sucked, the movement of the transfer arm 1 is stopped at a desired position, the above suction is released, and the substrate 11 is peeled off from the holding unit 12. Then, the substrate 11 is transported to a desired position.

  Since the substrate 11 is attracted to the holding unit 12, the holding direction of the substrate 11 may be any direction. In FIGS. 1A and 1B, the substrate 11 is held above the holding unit 12. For example, the support unit 15 is turned upside down to hold the substrate 11 below the holding unit 12. It may be.

  Here, if the adsorption and desorption of the substrate 11 are repeated, the substrate 11 may be charged with static electricity and the substrate 11 may not be separated from the holding unit 12. In such a case, it is necessary to neutralize the substrate 11. Usually, using an ionizer, ionized air having a charge opposite to the above charge is sent to the substrate 11 to remove the charge, or contact with another grounded member or wiring to charge the substrate 11 charged. Static electricity is removed by escaping to the ground. However, when an ionizer is used, there are problems unique to the ionizer described above.

  The size (here, the diameter of the facing surface facing the substrate 11) d of the conductive coating 14 is preferably larger in order to improve the charge removal performance of removing the substrate 11. That is, the area of the opposing surface of the conductive coating 14 is preferably larger in order to improve the charge removal performance.

  In FIG. 1, the metal part 13 and the support part 15 are separated from each other and a transfer arm configured to be screwed and fastened is shown. However, the metal part 13 and the support part 15 are substantially formed. Needless to say, even a single unit is included in the transfer arm of the present invention.

  For example, the metal part 13 is integrated on the support part 15 by welding to the support part 15 as a metal rod, and fixed by inserting the holding part 12 having a through-hole through which the metal part 13 can be inserted from above. Even a transfer arm having such a configuration is included in the scope of the present invention.

  The inventor has found that there is a case where the substrate 11 can be neutralized even by the transfer arm 1 having the configuration without the conductive coating 14. Specifically, in the configuration shown in FIG. 1, the conductive coating 14 is a space. That is, there is a gap between the substrate 11 and the metal part 13. In the gap, the distance between the substrate 11 and the metal component 13 may be 1 mm to 10 mm, that is, the substrate 11 may be neutralized by bringing the substrate 11 and the metal component 13 close to each other.

  In the above-described static elimination, when the potential is locally increased by charging the substrate 11, the potential difference between the substrate 11 and the metal component 13 increases, and a discharge phenomenon occurs in the gap, and the charge charged on the substrate 11. May have moved to the metal part 13.

  Further, when the metal component 13 has the conductive coating 14 on the surface facing the substrate 11 and is not in contact with the substrate 11, the generation of metal contamination on the substrate 11 is more effectively suppressed, and the neutralization of the substrate is performed. It also has the effect of being able to.

<About effect>
As described above, the transfer arm 1 can prevent the substrate 11 from sticking to the holding unit 12 due to charging while suppressing the occurrence of metal contamination. Therefore, there is an effect that troubles at the time of transporting the substrate 11 can be reduced.

[Embodiment 2]
An embodiment of the present invention will be described with reference to FIG.

<Transfer device using transfer arm>
FIG. 2 is a conceptual diagram showing a schematic configuration of the transport apparatus 2 according to the present invention.

  FIG. 2 shows a situation in which the substrate 11 is transferred from a predetermined position to another predetermined position using the transfer arm 1 described above as a part of the transfer device 2.

  The transport device 2 includes a transport arm 1, a drive unit 21, a vacuum pump 22, and a belt conveyor 23. The transfer arm 1 is connected to the drive unit 21, moves in the vertical direction, and can rotate around the axis of the drive unit 21.

  In this figure, the drive mode of the transport arm 1 by the drive unit 21 shows only translation in the vertical direction and rotation around the axis of the drive unit 21, but the drive unit 21 performs such translation and rotation. The transfer arm 1 may be driven in any direction as long as the configuration allows, without being limited thereto.

  First, it is assumed that the substrate 11 is stacked as shown in the lower left of FIG. The transport arm 1 is driven using the drive unit 21, and the suction surface of the transport arm 1 (the surface facing the direction in which the hole opened at the center of the transport arm 1) is brought into contact with the stacked body of the substrates 11. This suction surface is the suction surface of the holding part 12 of FIG.

  Next, the hole of the transfer arm 1 is set to a low pressure or a vacuum using the vacuum pump 22. While maintaining this low pressure or vacuum, the transport arm 1 is moved by the drive unit 21 to transport the substrate 11 onto the belt conveyor 23. Finally, the low pressure or vacuum is released at a predetermined speed, and the substrate 11 is lowered onto the belt conveyor 23 at the predetermined speed. Thereafter, the substrate 11 is transported by the belt conveyor 23 to a later process (not shown). Here, the above-mentioned “predetermined speed” refers to a speed at which a sufficient margin can be secured for performing suction, conveyance, and suction release without damaging the substrate 11 and removing electricity between the intervals. It is preferable that the speed is higher if it can be transported without damaging 11 and the charge can be removed sufficiently.

<About effect>
As described above, the transport device 2 using the transport arm 1 can prevent the occurrence of metal contamination, prevent the substrate 11 from sticking to the transport arm 1 due to charging, and reduce troubles during transport. .

[Modification 1]
Next, based on FIG. 3, a modified example of the first embodiment will be described.

  3A and 3B show an embodiment in which the positions of the metal component 13 and the conductive coating 14 in FIG. 1 are changed. FIG. 3A is a top view thereof, and FIG. 3B is a cross-sectional view taken along the line AA of FIG. It is.

  The description of the same configuration as that described above is omitted.

  In FIG. 3, the positions of the metal part 13 and the conductive coating 14 are different from those in FIG. As shown in FIG. 3, the conductive coating 14 may be in any position as long as it is in contact with the substrate 11.

  3, the metal part 13 and the conductive coating 14 are all provided outside the holding part 12, and the metal part 13 and the conductive coating 14 are all provided inside the holding part 12 in FIG. 1. If the conductive coating 14 is in contact, the metal part 13 and a part of the conductive coating 14 are provided inside the holding part 12, or the metal part 13 and the conductive coating 14 are provided in the holding part 12. It may be in the form of being in contact with.

  However, when the substrate 11 is attracted to the holding portion 12, the substrate 11 is inclined to some extent by the attracting force. In other words, the substrate 11 is warped. This is because there is tolerance of the shape of the holding portion 12 and deformation of the substrate 11 itself (at the time of suction, the suction surface of the holding portion 12 or the vicinity of the hole is curved to the holding portion 12 side as a vertex).

<About effect>
As described above, the positions of the metal component 13 and the conductive coating 14 are not particularly limited to the positions shown in FIGS. 3 and 1 as long as the substrate 11 and the conductive coating 14 are in contact with each other. Further, the substrate 11 and the conductive coating 14 may be provided by providing a part or all of the metal part 13 and the conductive coating 14 inside the holding unit 12 or bringing the metal part 13 and the conductive coating 14 into contact with the holding unit 12 by using a jig (not shown). The relative positional relationship between the substrate 11 and the conductive coating 14 can be maintained even when the transfer arm 1 is moved by the transfer of the substrate 11 and the like. Static elimination can be realized.

[Modification 2]
Next, another modification of the above-described first embodiment will be described with reference to FIG.

  FIG. 4 shows an embodiment in which the number of metal parts 13 and conductive coatings 14 in FIG. 1 is changed, (a) is a top view thereof, and (b) is a cross-sectional view of the AA cross section of (a). It is.

  A description of the same components as those described above is omitted.

  In FIG. 4, the number of metal parts 13 and conductive coatings 14 is different from that in FIG. As shown in FIG. 4, the number of the metal parts 13 and the conductive coating 14 may be any number as long as the necessary static elimination performance can be achieved without causing metal contamination. That is, as shown in FIG. 4, the number may be more than four, or may be four or less and one or more.

<About effect>
As described above, the number of metal parts 13 and conductive coatings 14 is not particularly limited to the number shown in FIGS. Therefore, the degree of freedom in manufacturing the transfer arm is increased, and it is possible to easily provide a transfer arm suitable for static elimination and transfer.

[Modification 3]
Next, another modification of the first embodiment will be described with reference to FIG.

  FIG. 5 shows an embodiment in which the area (diameter) of the metal part 13 and the conductive coating 14 in FIG. 1 is changed, (a) is a top view thereof, and (b) is an AA cross section of (a). FIG.

  A description of the same components as those described above is omitted.

  In FIG. 5, the areas of the metal part 13 and the conductive coating 14 are different from those in FIG. As shown in FIG. 5, the metal component 13 and the conductive coating 14 may have any area as long as the metal component 13 and the conductive coating 14 do not cause metal contamination and can achieve the necessary static elimination performance. That is, as shown in FIG. 5, the area may be larger or smaller than that in FIG.

<About effect>
As described above, the areas of the metal part 13 and the conductive coating 14 are not particularly limited to the areas shown in FIGS. Therefore, the degree of freedom in manufacturing the transfer arm is increased, and a transfer arm suitable for charge removal and transfer can be easily provided.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  A transfer arm, a transfer device including the transfer arm, and a transfer method using the transfer arm according to the present invention perform conductive charge on a grounded metal component and remove the charge by bringing the conductive coating into contact with a charged substrate. Therefore, the present invention can be used for various applications in which the substrate is transported while neutralizing electricity while suppressing metal contamination.

1 Transfer Arm 11 Substrate 12 Holding Unit 13 Metal Parts (Grounding Unit)
14 Conductive coating (conductive part)
15 Supporting part d Size 2 Conveying device 21 Driving part 22 Vacuum pump 23 Belt conveyor

Claims (10)

A substrate transfer arm,
A holding portion made of an insulator that holds the substrate in contact with the substrate;
A grounding portion made of a conductor,
A transfer arm comprising: a conductive portion made of a conductor in contact with the substrate and the grounding portion. The conductive part is located between the substrate and the ground part,
The transfer arm according to claim 1, wherein the transfer arm is fixed by the grounding portion.   The transport arm according to claim 1, wherein the conductive portion is a coating made of a conductive material applied to a part of the grounding portion. A support portion for fixing the holding portion;
The transfer arm according to claim 1, wherein the grounding portion is fixed to the support portion.   The transport arm according to claim 4, wherein the grounding portion is a fixing member that fixes the holding portion to the support portion.   The transfer arm according to any one of claims 1 to 5, wherein a part or all of the conductive portion is provided inside the holding portion.   The transport arm according to claim 1, wherein the conductive portion is in contact with the holding portion.   The transport arm according to claim 1, wherein there are a plurality of sets of the grounding part and the conductive part.   The conveyance apparatus using the conveyance arm of any one of Claims 1-8. A holding portion made of an insulator for holding the substrate in contact with the substrate;
A grounding portion made of a conductor,
A transport method for transporting the substrate using a transport arm comprising a conductive portion made of a conductor in contact with the substrate and the grounding portion,
Holding step for holding the substrate in the holding portion;
And a neutralizing step of neutralizing the substrate and the conductive portion by contacting with each other.

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