JP2007324169A - Carrying arm, substrate carrier, and substrate inspection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrier arm which can carry even a warped substrate while supporting surely. <P>SOLUTION: The carrier arm 10 includes an evacuation path 12 in the arm body 11 along the axial direction, and includes a sucking portion 14 as a support having a suction hole 13 communicating with the evacuation path 12 on the upper surface of the arm body 11 on the free end side. On the upper surface of the arm body 11 close to the proximal portion thereof and opposing the circumferential edge of a wafer 20 supported by the sucking portion 14, a concave 15 is provided as the recess of the circumferential edge of the wafer 20 warped to the arm body 11 side (recessed not to touch the circumferential edge). The concave 15 extends to penetrate the arm body 11 in the direction intersecting the axial direction perpendicularly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transfer arm that can reliably support and transfer even a substrate such as a warped wafer, a substrate transfer apparatus including the transfer arm, and a substrate inspection apparatus.

  In the manufacturing process of a substrate such as a semiconductor wafer or a glass substrate for a display, a plurality of thin films can be sequentially stacked on the substrate surface by repeating thin film formation, photosensitive agent coating, exposure, etching, inspection, and other steps. Has been done. In each of these processes, every time the processes such as the thin film forming process, the photosensitive agent coating process, the exposure process, and the etching process are completed, the substrate is accommodated in the cassette and transported to the next process, and the substrate is taken out from the cassette again. A substrate transfer device equipped with a transfer arm is used to take out (load) a substrate from the cassette and return (unload) the substrate into the cassette.

  The transfer arm has, for example, an arm main body that supports and transfers a substrate by vacuum suction. On the upper surface of the free end side of the arm body, a substantially cylindrical adsorbing portion that is slightly raised as compared with other portions is formed, and the back surface of the substrate is adsorbed and supported on the adsorbing portion. Accordingly, the substrate is supported in a state of being slightly lifted on the upper surface of the arm body except for the central portion of the back surface that is adsorbed by the adsorbing portion, and the substrate is warped to the arm body side due to the influence received during the above-described process. Even so, it was rare to contact the upper surface of the arm body.

  In recent years, it has been required to stack a large number of thin films on the surface of the substrate by increasing the density of the wiring formed on the surface of the substrate, and as a result, the number of repetitions of the above-described processes has increased, resulting in the amount of warping of the substrate. Tend to increase. In addition, an increase in the size of the substrate, for example, a 12 inch (300 mm) wafer is used, and the amount of warpage may increase due to the weight of the substrate. When the amount of warpage of the substrate increases in this way, the peripheral portion of the substrate comes into contact with the upper surface of the arm body, while a gap is generated between the central portion of the back surface of the substrate and the suction portion, and a suction error that cannot suck the substrate occurs. Sometimes.

  As a means for eliminating such an adsorption error, for example, it is conceivable to provide two or more adsorption units on the arm body, and adsorb and support the substrate by any of the adsorption units. The contact with the substrate increases the risk of particles adhering to the substrate.

  For example, a flat sheet having a through-hole communicating with the vacuum suction hole on the vacuum suction hole formed on the arm is used as a means to reliably suck and support a warped substrate without increasing the number of suction parts. A substrate transport arm has been proposed in which only the vicinity of the center of the planar sheet is joined to the arm so that the outer periphery of the planar sheet can be deformed to the substrate side (see Patent Document 1).

JP 2000-133694 A

  However, in order to load and unload the substrate, it is necessary to move the arm main body into the gap between the substrates accommodated in the cassette, and the thickness of the arm main body at the portion where the suction part is formed This is limited by the gap between the substrates. That is, it is necessary to prevent the lower surface of the arm body from rubbing against other adjacent substrates during loading and unloading, and the height of the suction portion is limited. Considering that an evacuation passage communicating with the suction part must be formed inside the arm body, the height of the suction part can be taken only a little, and the above-mentioned proposal for increasing the suction part is not a good idea anyway. .

  The present invention has been made in view of the above circumstances, and provides a transport arm that can reliably support and transport even a warped substrate, and a substrate transport apparatus and a substrate inspection apparatus provided with the transport arm. With the goal.

  The transport arm according to claim 1 of the present invention that achieves the above object comprises an arm body that supports and transports a substrate, and a recess provided on a side of the arm body on which the substrate is supported. It is characterized by.

  Examples of the substrate include a glass substrate for a liquid crystal display and a plasma display in addition to a semiconductor wafer.

  According to a second aspect of the present invention, the transfer arm is provided with a support portion at a position of the arm main body capable of supporting the central portion of the substrate, and at a portion facing the peripheral portion of the substrate supported by the support portion. The concave portion is provided.

  The support part includes, for example, a suction part that vacuum-sucks the substrate, but is not limited thereto. The one that simply supports the substrate so as not to slide down is also included.

  The transfer arm according to a third aspect of the present invention is characterized in that the support portion supports the substrate by vacuum suction.

  In the transfer arm according to a fourth aspect of the present invention, the recess is set to a depth at which the peripheral edge of the substrate does not contact.

  According to a fifth aspect of the present invention, when the center of the support portion and the center of the substrate are aligned between the peripheral edge portion of the substrate and the one end edge of the concave portion near the peripheral edge portion. A gap of 3% to 10% of the diameter of the substrate or the length of the long side or the length of the short side of the substrate is provided.

  A substrate transfer apparatus according to a sixth aspect of the present invention includes the transfer arm according to any one of the first to fifth aspects, and a drive unit that drives the transfer arm.

  A substrate inspection apparatus according to a seventh aspect of the present invention includes the transfer arm according to any one of the first to fifth aspects, and an inspection unit that inspects a wafer transferred by the transfer arm. Features.

  According to the transfer arm of the first aspect of the present invention, since the recess is provided on the side of the arm body on which the substrate is supported, the recess acts to avoid contact between the arm body and the substrate, Even a warped substrate can be reliably supported and transported by the arm body. Therefore, it is not necessary to raise a part of the arm body so as to lift and support the substrate on the arm body except for a part thereof.

  According to the substrate transfer apparatus according to claim 6 of the present invention, since the transfer arm according to any one of claims 1 to 5 is provided, it is desired to reliably support even a warped substrate. Therefore, it is possible to increase the conveyance efficiency by increasing the conveyance speed.

  According to the substrate inspection apparatus according to claim 7 of the present invention, since the transport arm according to any one of claims 1 to 5 is provided, the substrate in which warpage has occurred is reliably supported and inspected. Therefore, it is possible to transfer to the inspection section and from the inspection section, and to improve the inspection efficiency by increasing the efficiency of the substrate transfer.

  Hereinafter, an embodiment of a transfer arm, a substrate transfer apparatus equipped with the transfer arm, and a substrate inspection apparatus according to the present invention will be described with reference to FIGS.

  FIG. 1 is a plan view showing an embodiment of the transfer arm of the present invention, and FIG. 2 is an enlarged vertical sectional view of the transfer arm of FIG.

  The transfer arm 10 is provided with a vacuum exhaust path 12 along the axial direction inside the arm main body 11, and supports an upper surface (a wafer 20 as a substrate) on the free end side (downward in FIG. 1) of the arm main body 11. A suction portion 14 as a support portion having a suction hole 13 communicating with the vacuum exhaust path 12 is provided on the side).

  The vacuum exhaust path 12 opens on the back surface (lower surface) of the base side (upper side in FIG. 1) of the arm body 11 and is connected to a vacuum pump (not shown).

  The suction portion 14 is slightly raised on the upper surface of the arm body 11 and formed in a ring shape. Therefore, the wafer 20 placed on the suction unit 14 is supported in a state of being lifted on the upper surface of the arm main body 11 except for the central portion of the back surface that is sucked by the suction unit 14. The contact between the arm body 11 and the wafer 20 is limited to the necessary minimum portion by limiting the contact between the suction portion 14 and the central portion of the back surface of the wafer 20. In other words, the contact area of the wafer 20 with the arm body 11 is suppressed as much as possible to reduce the adhesion of particles to the wafer 20. In the present embodiment, two suction portions 14 are provided, which are supported in a stable state so that the suction portion 14 vacuum-sucks the back surface of the central portion of the wafer 20 and does not slide off from the arm body 11. It is to do. When the outer diameter of the wafer 20 to be supported is small, only one suction portion 14 is required. The central portion of the wafer 20 supported by the suction unit 14 is not only the center point of the back surface of the wafer 20 but also the central portion of the back surface of the wafer 20 including the back surface portion corresponding to the center of gravity of the wafer 20.

  A recess 15 is provided on the upper surface near the base of the arm body 11, which faces the peripheral edge of the wafer 20 supported by the suction unit 14, so as to penetrate in a direction orthogonal to the axial direction of the arm body 11. The recess 15 serves as a relief of the peripheral edge of the wafer 20 warped toward the arm body 11 (depresses so that the peripheral edge does not contact).

  The depth of the recess 15 is set to be larger than the value obtained by subtracting the height of the suction portion 14 from the amount of warpage of the wafer 20. For example, when the wafer 20 is 12 inches (300 mm), the amount of warpage is said to be about 1 mm. Therefore, when the height of the suction portion 14 is set to 0.2 mm to 0.5 mm, for example, the depth of the recess 15 is increased. The thickness is set to 0.5 mm to 0.8 mm or more. Setting the depth of the recess 15 to be larger than necessary reduces the mechanical strength of the arm body 11, so that the depth of the recess 15 can be kept to the minimum necessary to avoid contact with the wafer 20. Further, a margin is provided between the peripheral edge of the wafer 20 and the one end edge 15a of the recess 15 located near the peripheral edge. That is, a gap is provided between the peripheral edge of the wafer 20 and the one end edge 15 a of the recess 15. This is because when the wafer 20 is supported by the suction portion 14 with the center portion of the wafer 20 and the center of the suction portion 14 being out of alignment (eccentric) and being supported by the suction portion 14, the peripheral edge portion of the wafer 20 is one end edge 15 a of the recess 15. This is so as not to touch the surface. For example, the gap is set to be about 3% to 10% of the diameter of the wafer 20 when the center of the wafer 20 and the center of the suction portion 14 are aligned. In the case of a rectangular glass substrate instead of the wafer 20, the center of the glass substrate and the center of the suction portion are arranged between the edge of the long side or the short side of the glass substrate and the one end edge 15 a of the recess 15. Are combined to give a gap of about 3% to 10% of the dimension of the long side or short side of the glass substrate. Further, the position of the other end edge 15 b of the recess 15 away from the peripheral edge of the wafer 20 is set so as not to contact the back surface of the wafer 20. The position of the other end edge 15b of the recess 15 differs somewhat depending on the warp curve of the wafer 20, but the position of the other end edge 15b determines the width of the recess 15 in the axial direction of the arm body 11 together with the position of the one end edge 15a. It will be. As described above, the width of the recess 15 is also a factor for reducing the mechanical strength of the arm body 11, and can be suppressed to the minimum necessary to avoid contact with the wafer 20.

  According to the transfer arm 10 of the present embodiment, when a vacuum pump (not shown) is driven, the vacuum suction force acts on the center portion of the back surface of the wafer 20 on the suction portion 14 from the suction hole 13 via the vacuum exhaust path 12. . At this time, if the wafer 20 is warped, and the warpage is such that the peripheral portion is below the center portion of the wafer 20, the peripheral portion of the wafer 20 will come into contact with the portion of the arm body 11 facing the peripheral portion. However, since the concave portion 15 is provided at this portion, the peripheral portion of the wafer 20 enters the concave portion 15 to avoid contact with the arm body 11, and the central portion of the wafer 20 is lifted from the suction portion 14 due to warpage. There is nothing.

  Therefore, the suction part 14 can be reliably supported on the suction part 14 by the vacuum suction force acting from the suction hole 13 even if the suction part 14 is raised slightly without raising it. Further, since it is not necessary to increase the thickness of the arm body 11 at the portion of the suction portion 14, for example, when the wafer 20 is taken out from a cassette containing the wafer 20, the arm body 11 enters the gap between the wafers 20. Even if it makes it, it does not have a possibility of contacting the wafer 20 other than the take-out object, for example, another wafer 20 located below the wafer 20 to be taken out.

  FIG. 3 shows an embodiment of the substrate transfer device 30 and the substrate inspection device 40 of the present invention having the transfer arm 10 described above.

  The substrate transfer apparatus 30 includes a transfer arm 10, motors 31, 32, and 33 as drive units that drive the transfer arm 10, guide rails 34 that guide the transfer arm 10, and the like, and a base 41 of the substrate inspection apparatus 40. It is arranged behind the upper end (upper left in FIG. 3). The motor 31 moves the transfer arm 10 in the arrow X direction shown in FIG. 3, the motor 32 moves the transfer arm 10 in the arrow Y direction shown in FIG. 3, and the motor 33 moves the transfer arm 10 in the arrow Z direction shown in FIG. Move in the vertical direction with respect to the page. The transfer arm 10 is driven by the motors 31, 32, 33, and is guided by the guide rail 34 to move in the directions of arrows X, Y, and Z in FIG. 3, and forward of one end on the base 41 (lower left in FIG. 3). The wafer 20 is taken out from the cassette 50 installed in the machine. The wafer 20 taken out on the transfer arm 10 is transferred to a rotary arm 60 comprising three semi-arc-shaped arms 61 at intervals of 120 °.

  The substrate inspection apparatus 40 includes a microscope observation unit as an inspection unit disposed on the other end side (right side in FIG. 3) on the pedestal 41 in addition to the substrate transfer apparatus 30 and the rotation arm 60 provided with the transfer arm 10. 42 is provided. The microscope observation unit 42 is for observing the wafer 20 transferred from the cassette 50 by the transfer arm 10 and the rotary arm 60 under a microscope, and includes an objective lens having various magnifications so as to be exchangeable.

  According to the substrate transfer apparatus 30 of the present embodiment, since the transfer arm 10 is provided, the warped wafer 20 can be reliably supported and transferred to the rotary arm 60 without slipping down. It is possible to increase the speed and increase the conveyance efficiency.

  Further, according to the substrate inspection apparatus 40 of the present embodiment, since the substrate transfer apparatus 30 including the transfer arm 10 is mounted, the wafer 20 that is warped is reliably supported and transferred to the microscope observation unit 42. In addition, transfer from the microscope observation unit 42 to the cassette 50 can be performed, and the inspection efficiency can be improved by increasing the efficiency of substrate transfer.

  The transfer arm of the present invention is not limited to that shown in the above-described embodiment. The recess 15 may be formed on the side (for example, the upper surface or the surface) of the arm body 11 on which the substrate (the wafer 20 or the display glass substrate) is supported. If the recess 15 is formed, even if the substrate is warped, contact between the substrate and the arm main body can be avoided except for a portion where the substrate is supported (for example, a portion that contacts the suction portion 14). . In the present embodiment, the cross-sectional shape of the recess 15 in the arm longitudinal direction is rectangular. However, a part of the cross-sectional shape may be an arc, a smooth curve, or a polygon.

  The transfer arm of the present invention is not limited to the substrate inspection apparatus 40 described above, and can be applied to, for example, an exposure apparatus (stepper) that transfers a mask pattern to a photosensitive agent applied on a substrate.

It is a top view which shows one Embodiment of the conveyance arm of this invention. FIG. 2 is an enlarged longitudinal sectional view of a transfer arm in FIG. 1. It is a schematic plan view of the board | substrate inspection apparatus which has arrange | positioned the board | substrate conveyance apparatus which has the conveyance arm of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transfer arm 11 Arm main body 14 Adsorption part 15 Recess 20 Wafer (substrate)
30 Substrate transport device 31, 32, 33 Motor (drive unit)
40 Substrate inspection device 42 Microscope observation part (inspection part)

Claims (7)

An arm body for supporting and transporting the substrate;
And a recess provided on a side of the arm body on which the substrate is supported. The transfer arm according to claim 1,
A conveyance part, wherein a support part is provided at a position of the arm main body capable of supporting a central part of the substrate, and the concave part is provided at a part facing the peripheral part of the substrate supported by the support part. arm. The transfer arm according to claim 2,
The transfer arm, wherein the support portion supports the substrate by vacuum suction. In the transfer arm according to claim 2 or 3,
The transport arm according to claim 1, wherein the recess is set to a depth at which the peripheral edge of the substrate does not contact. The transfer arm according to any one of claims 2 to 4,
When the center of the support portion and the center of the substrate are aligned between the peripheral edge and one end edge of the recess near the peripheral edge, the diameter of the substrate or the length of the long side of the substrate is short or short. A transfer arm having a gap of 3% to 10% of a side length. A transfer arm according to any one of claims 1 to 5,
And a drive unit for driving the transfer arm. A transfer arm according to any one of claims 1 to 5,
An inspection unit for inspecting the wafer transported by the transport arm.

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