JP2017150937A - Substrate inspection device and sluice valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate inspection device and a sluice valve detection with which it is possible to accurately detect a crack or a chip having occurred in an edge portion of a substrate to be inspected, without being affected by the surface condition of the substrate to be inspected.SOLUTION: This substrate inspection device IV, provided with conveyance means for conveying a substrate W to be inspected that is held by a robot hand 13 in one direction and detection means 25 for capturing the image of a substrate to be inspected and detecting a crack or a chip having occurred in an edge portion, further includes a light source 24 for irradiating one face of the substrate to be inspected with a linear light spreading across the substrate to be inspected in the radial direction, one that passes through the robot hand and is cut off by the substrate to be inspected being selected as an irradiation light from the light source, with an imaging unit 25a of the detection means arranged on the other face side of the substrate to be inspected.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a substrate inspection device and a gate valve device that detect cracks and chips generated at an edge portion of a substrate to be inspected.

  Conventionally, a transfer robot having a robot hand as a carrier for holding a substrate is disposed as a vacuum processing apparatus that performs a plurality of processes such as heat treatment, film formation process and etching process on a substrate to be processed in a vacuum atmosphere. There is known a so-called cluster tool comprising a transfer chamber and a plurality of processing chambers arranged so as to surround the transfer chamber. Usually, the transfer chamber and each processing chamber are connected via a gate valve device that can selectively isolate both chambers.

  By the way, the substrate as a processing object has been increased in size and thickness, and accordingly, the edge portion of the substrate may be cracked or chipped due to distortion or stress caused by the predetermined processing. If such a crack or chipping occurs, for example, the substrate is likely to be damaged at the time of transfer, and if the substrate is damaged in the transfer chamber or the processing chamber, the substrate needs to be removed, resulting in a decrease in productivity. . For this reason, it is desired to be able to detect as much as possible a crack or chip in the edge portion that leads to breakage of the substrate.

  A detection apparatus for detecting a crack in a substrate is known from Patent Document 1, for example. In this apparatus, a conveyance belt is used as a conveyance means, the substrate is held on the conveyance belt and conveyed in one direction, and the substrate to be inspected is imaged by the imaging unit disposed on the upper surface side of the substrate. Cracks and chips generated in are detected. However, the substrate as the substrate to be inspected may be exposed to a film having a high reflectance such as a metal film by performing a predetermined process. For this reason, even if it is going to image a to-be-inspected board | substrate with an imaging part like the said prior art example, there exists a problem that a crack and a chip | tip cannot be detected accurately because the said imaging part is reflected.

JP 2008-102062 A

  In view of the above, the present invention provides a substrate inspection apparatus and a gate valve that can accurately detect cracks and chips generated in an edge portion of a substrate to be inspected without being affected by the surface state of the substrate to be inspected. It is an object of the present invention to provide an apparatus.

  In order to solve the above-mentioned problems, a book comprising transport means for transporting a substrate to be inspected held by a carrier in one direction, and detection means for detecting a crack or a chip generated at an edge portion by imaging the substrate to be inspected. The substrate inspection apparatus according to the present invention further includes a light source that irradiates a line-shaped light straddling the inspection substrate in a radial direction toward one surface of the inspection substrate, and transmits the carrier as irradiation light from the light source. And the image pickup unit of the detecting means is arranged on the other surface side of the substrate to be inspected.

  According to the present invention, the irradiation light from the light source passes through the carrier but does not pass through the substrate to be inspected, so that the contrast between the substrate to be inspected and the carrier increases in the image obtained by the imaging unit. It seems that the edge part of the substrate to be inspected, which is the boundary part between the carrier and the carrier, is lifted. For this reason, the crack and the chip | tip which arose in the said edge part can be detected accurately. Moreover, since an image is not acquired from the reflected light on the surface of the substrate to be inspected, the surface state of the substrate to be inspected is not affected.

  In the present invention, when the substrate to be inspected is a silicon wafer and the carrier is a robot hand of a transfer robot disposed in a vacuum chamber, the robot hand is made of aluminum oxide having a plate thickness of 0.5 mm to 5.0 mm. It is preferable that the light source is made of a material that emits irradiation light having a central wavelength in the range of 380 to 750 nm. According to this, it was confirmed by an experiment described later that the robot hand can emit light.

  Further, the gate valve device of the present invention, which is interposed between the first vacuum chamber and the second vacuum chamber which are continuously provided in one direction and selectively isolates the first vacuum chamber and the second vacuum chamber, A valve body and a valve body provided in the valve box so as to be able to reciprocate, and is held by a carrier in a connecting direction of the first vacuum chamber and the second vacuum chamber perpendicular to the reciprocating direction of the valve body. A line that is provided on the wall surface of the valve box that is transported and located on one side of the reciprocating direction, and that straddles the substrate to be inspected in the radial direction toward one surface of the substrate to be inspected that is held and transported by the carrier A light source that irradiates a shaped light and an imaging unit that is provided on the wall surface of the valve box that is located on the other side of the reciprocating direction, and that captures cracks and chips generated at the edge of the substrate to be inspected. And detecting means for detecting.

  According to this, it is possible to detect cracks and chips generated at the edge portion of the substrate from the image of the substrate to be inspected while the substrate to be inspected passes through the valve box of the gate valve device. If detected, the substrate can be prevented from being damaged by immediately prohibiting the conveyance of the substrate to be inspected.

The figure explaining the cluster tool to which the gate valve apparatus of embodiment of this invention is applied. The figure which shows the state which the board | substrate W passes the gate valve apparatus IV interposed between the 1st vacuum chamber T shown in FIG. 1, and the 2nd vacuum chamber C1. The figure explaining area | region Ra where irradiation light is interrupted | blocked by the board | substrate W, and area | region Rb which permeate | transmits the robot hand 13. FIG. The schematic diagram which shows the image of the whole board | substrate W obtained from the image imaged by the imaging part. The figure which shows the modification of a gate valve apparatus. (A) And (b) is the photograph which shows the experimental result of this invention.

  Hereinafter, a substrate inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings, taking as an example a gate valve apparatus IV assembled to a vacuum processing apparatus constituted by a cluster tool. As shown in FIG. 1, a sputtering apparatus M as a vacuum processing apparatus includes a central transfer chamber T in which a transfer robot R that holds a substrate W is disposed, and processing chambers C1 and C1 that are disposed so as to surround the transfer chamber T. C2 and load lock chambers L1 and L2. The transfer chamber T, the load lock chambers L1 and L2, and the processing chambers C1 and C2 can be evacuated by a vacuum pump (not shown). The transport robot R has two motors (not shown), and the robot arms 12 are connected to the rotation shafts 11a and 11b of the motors arranged concentrically via a link mechanism (not shown). A robot hand 13 that holds the substrate W is attached to the tip. By appropriately controlling the rotation angles of the rotation shafts 11a and 11b, the robot arm 12 can be expanded and contracted and swiveled, and the substrate W held by the robot hand 13 can be transported to a predetermined position in each chamber. .

  The transfer chamber T, the load lock chambers L1 and L2, and the processing chambers C1 and C2 are connected to each other via the gate valve device IV of the present embodiment so that the chambers can be isolated from each other. Referring also to FIG. 2, the gate valve device IV is provided so as to freely reciprocate between a valve box 21 and a valve opening position indicated by a solid line and a valve closing position indicated by a virtual line in the valve box 21. The valve body 22 is provided. In the following, the reciprocating direction of the valve body 22 is the Z-axis direction, and the connecting direction of the transfer chamber (first vacuum chamber) T and the processing chamber (second vacuum chamber) C1 orthogonal to the Z-axis direction is the X-axis. This will be described as a direction.

  Through holes 21a and 21a are formed in the wall surface portion of the valve box 21 in the X-axis direction so as to face each other. In a state where the valve element 22 is moved to the valve opening position, the transfer chamber T and the processing chamber C1 communicate with each other through the through holes 21a and 21a, and the substrate W held by the robot hand 13 between the chambers T and C1. Can be transported.

  An exhaust port 30 is provided in the bottom wall of the vacuum chamber 1 that defines the processing chamber C1, and an exhaust pipe connected to a vacuum pump (not shown) is connected to the exhaust port 30 so that the processing chamber C1 can be evacuated. It has become. Although not shown, a gas pipe leading to a gas source is connected to the side wall of the vacuum chamber 1, and a rare gas such as Ar (or a mixed gas of rare gas and oxygen gas) is connected by a mass flow controller interposed in the gas pipe. Can be introduced into the processing chamber C1 at a predetermined flow rate. A target 32 that is appropriately selected according to the composition of the thin film to be deposited is disposed on the ceiling of the vacuum chamber 1. ) And the target 32 is cooled during film formation. An output from a sputtering power source E having a known structure is connected to the target 32, and DC power is input to the target 32 during sputtering. Above the backing plate 33, a magnet unit 34 having a known structure for generating a magnetic field in a space below the lower surface (sputtering surface) of the target 32 is arranged, and the sputtered particles from the target 32 are efficiently ionized. A stage 35 is disposed at the bottom of the vacuum chamber 1 so as to face the target 32 so that the substrate W is positioned and held with its film formation surface facing upward. In addition, upper and lower deposition prevention plates 36u and 36d are disposed in the processing chamber C1, so that sputter particles do not adhere to the inner wall surface of the vacuum chamber 1. The deposition preventing plate 36d can be moved up and down by an elevating means 37 between a lowered position at the time of transporting the substrate W and an elevated position at the time of film formation.

  By the way, the edge portion of the substrate W may be cracked or chipped. If such a crack or chipped portion is generated, for example, the substrate W is easily damaged at the time of transport. When it breaks, it becomes necessary to remove the substrate W, and productivity is lowered.

  Therefore, in the present embodiment, a glass window 23a is provided on the wall surface located on the lower side in the Z-axis direction of the valve box 21, and the substrate is directed toward the lower surface of the substrate W held and transported by the robot hand 13 in the glass window 23a. A light source 24 for irradiating linear light straddling W in the radial direction (Y-axis direction) was provided. Further, a glass window 23b is provided on the wall surface located on the upper side in the Z-axis direction of the valve box 21, and the glass window 23b has an image pickup unit 25a for picking up an image of the substrate W. The detection means 25 which detects this is provided. As the light source 24, at least one laser projector can be used. As the irradiation light from the laser projector, one that passes through the robot hand 13 and is shielded by the substrate W can be selected. In order for the linear light to straddle the substrate W in the Y-axis direction, it is preferable to use a plurality of laser projectors 24. Further, a line camera can be used as the imaging unit 25a. As these laser projector 24 and line camera 25a, since a well-known thing can be used, detailed description is abbreviate | omitted here.

  The sputtering apparatus M has a known control means (not shown) having a microcomputer, a sequencer, and the like. By this control means, in addition to the operation of the transfer robot R, the operation of the power supply E, the mass flow controller It is designed to oversee operation and operation of vacuum pumps. Further, the control means obtains a control signal related to the operation of the transfer robot R, obtains a passing time for the substrate W to pass through the valve box 21 based on the control signal, and irradiates light from the light source 24 from this passing time. Is controlled so that the transfer robot R can be stopped based on the detection result of the detection means 25. Hereinafter, the substrate transfer method of the present embodiment will be described by taking as an example the case where the substrate W is transferred from the transfer chamber T provided continuously via the gate valve device IV to the processing chamber C1.

  First, the substrate W is put into the load lock chamber L1 in the atmosphere, and after the load lock chamber L1 is evacuated, the substrate W is transferred from the load lock chamber L1 to the transfer chamber T by the transfer robot R.

  Next, a control signal related to the operation of the transfer robot R that transfers the substrate W in the transfer chamber T to the processing chamber C1 is acquired (acquisition step), and the substrate W passes through the valve box 21 based on the acquired control signal. Find time (passing timing). Then, when the substrate W passes through the valve box 21, light irradiation from the light source 24 is turned on. Thereby, light is irradiated from the Z-axis direction to the lower surface of the substrate W passing through the valve box 21.

  Here, the irradiation light from the light source 24 is selected so as to pass through the robot hand 13 while being shielded by the substrate W, so that the irradiation light from the light source 24 passes through the robot hand 13 but passes through the substrate W. do not do. Accordingly, as shown in FIG. 3, when the substrate W is viewed from the imaging unit 24a, the region Ra where the irradiation light is blocked by the substrate W becomes relatively dark, and the region Rb through which the irradiation light from the robot hand 13 passes is compared. Become brighter. As a result, the contrast between the substrate W and the robot hand 13 increases in the image captured by the imaging unit 24a. Then, as shown in FIG. 4, when the robot hand 13 is moved continuously from the transfer chamber T toward the processing chamber C1, and continuously captured by the imaging unit 24a, a plurality of images I1, I2,. n-1), In are obtained, and an image Iw of the substrate W is obtained by connecting the plurality of images I1, I2,..., I (n-1), In. In this image Iw, the contrast between the substrate W and the robot hand 13 increases, and the edge portion of the substrate W that is the boundary portion between the substrate W and the robot hand 13 appears to float. Therefore, based on this image Iw, the detection means 25 can accurately detect cracks and chips generated at the edge portion of the substrate W. When the detection means 25 detects a crack or a chip, the transfer by the transfer robot R is prohibited, and the transfer robot R is returned to the transfer chamber T. Thereby, damage to the substrate W can be prevented as quickly as possible. In addition, according to the present embodiment, since an image is not acquired from the reflected light on the surface of the substrate W, the surface state of the substrate W is not affected.

  When the substrate W is a silicon wafer, the robot hand 13 is made of porous ceramics made of aluminum oxide having a thickness of 0.5 mm to 5.0 mm, and the light source 24 has a central wavelength in the range of 380 to 750 nm. It is preferable to use an irradiation light. According to this, since the robot hand 13 can emit light like a backlight and the contrast between the silicon wafer W and the robot hand 13 can be further increased, chipping and cracking can be detected with higher accuracy. can do.

  As mentioned above, although embodiment of this invention was described, this invention is not limited above. In the above embodiment, the case where irradiation light is irradiated from the light source 24 disposed below the substrate W to the lower surface of the substrate W has been described as an example. The upper surface may be irradiated with irradiation light, and an image may be captured by an imaging unit disposed on the lower side of the substrate W. Further, an auxiliary light source may be disposed outside the light source 24 in the Y direction, and light from the auxiliary light source may be incident on the imaging unit 25a.

  In the above embodiment, the case where the irradiation light from the laser projector as the light source 24 is applied to the substrate W has been described as an example, but as shown in FIG. 5, the light from the laser projector 24 is applied to the diffusion lens 26, You may comprise so that the light diffused in the line form by the diffuser lens 26 may be irradiated to the lower surface of the board | substrate W. FIG.

  In the above-described embodiment, the line-shaped light straddling the substrate W in the Y-axis direction is irradiated. However, the line-shaped light may be irradiated so as to straddle not only the substrate W but also the robot hand 13 in the Y-axis direction. .

  In the above-described embodiment, the case where chipping or cracking is detected when transferring from the transfer chamber T to the processing chamber C1 has been described as an example, but detection may be performed when transferring from the load lock chamber L1 to the transfer chamber T. In the above embodiment, the cluster tool has been described as an example. However, the present invention can be applied to an inline apparatus.

  Next, experiments conducted by the present inventors will be described. In this experiment, as shown in FIG. 6A, a laser beam having a center wavelength of 650 nm is irradiated from a laser projector 24 onto a diffusion lens (resin transparent round bar) 26 to diffuse, and the diffused line-shaped light is 2 mm. The light was projected onto the upper surface of a robot hand 13 made of thick aluminum oxide. At this time, as shown in FIG. 6B, on the lower surface side of the robot hand 13, the line-shaped light is transmitted through the robot hand 13, and at this time, it is confirmed that the robot hand 13 emits light like a backlight. It was done.

  C1 ... processing chamber (second vacuum chamber), IV ... gate valve device, T ... transfer chamber (first vacuum chamber), R ... transfer robot (transfer means), W ... substrate (substrate to be inspected), 13 ... robot hand (Carrier), 21 ... Valve box, 22 ... Valve body, 24 ... Light source, 25 ... Detection means, 25a ... Imaging unit.

Claims (3)

In a substrate inspection apparatus comprising a transport unit that holds a substrate to be inspected by a carrier and transports the substrate in one direction, and a detection unit that captures an image of the substrate to be inspected and detects a crack or a chip generated in an edge portion.
It further includes a light source that irradiates a line-shaped light straddling the inspected substrate in the radial direction toward one surface of the inspected substrate, and the irradiation light from the light source is blocked by the inspected substrate while passing through the carrier. A substrate inspection apparatus, characterized in that the imaging unit of the detection means is selected on the other surface side of the substrate to be inspected. The substrate inspection apparatus according to claim 1, wherein the substrate to be inspected is a silicon wafer, and the carrier is a robot hand of a transfer robot in which the carrier is disposed in a vacuum chamber.
The robot hand is composed of translucent ceramics made of aluminum oxide having a plate thickness of 0.5 mm to 5.0 mm, and the light source irradiates irradiation light having a center wavelength in the range of 380 to 750 nm. The substrate inspection apparatus according to claim 1, wherein: A gate valve device that is interposed between a first vacuum chamber and a second vacuum chamber that are connected in one direction and selectively isolates the first vacuum chamber and the second vacuum chamber, A valve body provided in the valve box so as to freely reciprocate, and a substrate to be inspected held by a carrier in a connecting direction of the first vacuum chamber and the second vacuum chamber perpendicular to the reciprocating direction of the valve body. In what is transported,
A line-shaped light that is provided on the wall surface of the valve box located on one side of the reciprocating direction and that straddles the substrate to be inspected in the radial direction is irradiated toward one surface of the substrate to be inspected that is held and transported by the carrier. A light source, and a detection unit that is provided on a wall surface of a valve box located on the other side of the reciprocating direction and has an imaging unit that images a substrate to be inspected, and that detects a crack or a chip generated at an edge portion of the substrate to be inspected. A gate valve device further comprising: