Wafer inspection apparatus and wafer transfer apparatus

Abstract

To provide a wafer transfer apparatus and a wafer inspection apparatus capable of detecting a defect of a wafer more accurately than before.SOLUTION: A wafer inspection apparatus 11 discharges air from a ventilation block 18 on which a wafer 10 is disposed toward a surface of the wafer 10 to make the wafer 10 float horizontally above the ventilation block 18. A transfer unit 14 uses a drive unit 30 to make contact units 25 to 28 move mutually with respect to the ventilation block 18 to move the wafer 10 in one direction and makes the wafer 10 pass through an inspection information acquisition unit 15 while keeping the wafer floating horizontally. Thereby, the wafer inspection apparatus 11 uses the inspection information acquisition unit 15 to acquire a light reception result as information for inspection of the wafer 10 when the wafer 10 passes through the inspection information acquisition unit 15 and uses a detection unit 16 to detect a defect of the wafer 10 on the basis of the light reception result.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wafer inspection device and a wafer transport device. [Background technology]

[0002] Conventionally, wafer defects include microcracks that occur during manufacturing or transportation, pinhole defects introduced during crystal growth, twin defects, slip defects introduced during wafer heat treatment, and scratches introduced during wafer transportation. These defects include defects that reach from the back surface of the wafer to the front surface (defects that penetrate to the front surface), defects that exist only on the front or back surface of the wafer (defects that do not penetrate to the front surface), and defects that exist inside the wafer and cannot be seen from the front or back surface of the wafer.

[0003] Known wafer inspection devices for inspecting defects present inside a wafer are those that irradiate the wafer's inspection surface with infrared rays or X-rays (hereinafter also referred to simply as irradiated light) perpendicularly, detect the intensity of the infrared rays or X-rays transmitted through the inspection surface, and detect defects present between the front and back surfaces of the wafer (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-26954 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned wafer inspection apparatus, because the center of the wafer is held horizontally during inspection, warping or bending of the wafer may occur on the outer periphery due to its own weight, and unintended warping or bending of the wafer may make it difficult for the irradiated light from the light source to be perpendicularly incident on the wafer's inspection surface. Thus, if the irradiated light is not perpendicularly incident on the wafer's inspection surface, it is difficult to accurately detect defects inside the wafer. Furthermore, even in wafer inspection apparatuses that photograph the wafer's surface with an imaging unit such as a camera to inspect the wafer for defects on the surface, if warping or bending occurs on the outer periphery of the wafer, it is difficult for the imaging unit to image the wafer's inspection surface, making it difficult to accurately detect defects outside the wafer.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a wafer inspection apparatus and a wafer transport apparatus that can detect wafer defects more accurately than conventional apparatuses. [Means for solving the problem]

[0007] A wafer inspection device according to the present invention is a wafer inspection device that inspects wafers for defects, and includes: a stage on which the wafer is placed on a ventilated block, and which levitates the wafer horizontally above the ventilated block by discharging air from the ventilated block toward the surface of the wafer; a transport unit that transports the wafer, levitated horizontally above the stage by air, in one direction relative to the stage; an inspection information acquisition unit that acquires inspection information of the wafer; and a detection unit that detects the presence or absence of defects in the wafer based on the inspection information of the wafer acquired by the inspection information acquisition unit. The transport unit includes an abutment unit that abuts against the outer edge of the wafer, which is levitated horizontally above the stage by air, and a drive unit that moves the abutment unit relative to the stage. The drive unit moves the abutment unit relative to the stage to move the wafer in one direction, and the wafer passes through the inspection information acquisition unit while remaining horizontally levitated, and the inspection information acquisition unit acquires the inspection information of the wafer as the wafer passes.

[0008] Furthermore, a wafer transport device according to the present invention is a wafer transport device that passes a wafer through an inspection information acquisition section that acquires inspection information obtained from the wafer in order to inspect the presence or absence of defects in the wafer based on the inspection information, and includes: a stage on which the wafer is placed on a ventilation block, and which horizontally levitates the wafer above the ventilation block by discharging air from the ventilation block toward the surface of the wafer; and a transport section that transports the wafer that has been horizontally levitated above the stage by air in one direction relative to the stage, and the transport section includes an abutment section that abuts against the outer edge of the wafer that has been horizontally levitated above the stage by air, and a drive section that moves the abutment section relative to the stage, and the drive section moves the abutment section relative to the stage to move the wafer in one direction, and the wafer passes through the inspection information acquisition section while remaining horizontally levitated. [Effects of the Invention]

[0009] According to the present invention, by floating the wafer horizontally using air, it is possible to suppress the occurrence of warping or bending of the wafer, thereby reducing the effect of warping or bending of the wafer when inspecting for defects, and therefore it is possible to detect wafer defects more accurately than before. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing the overall configuration of a wafer inspection device according to an embodiment of the present invention. [Figure 2] 2 is a schematic diagram showing a state in which a wafer is placed at an initial position in the wafer inspection apparatus shown in FIG. 1. FIG. [Figure 3] 2 is a schematic diagram showing a state when the wafer has moved to a return position in the wafer inspection apparatus shown in FIG. 1. FIG. [Figure 4] FIG. 2 is a perspective view showing the configuration of an examination information acquisition unit. [Figure 5] 10 is an explanatory diagram for explaining a position where a light receiving unit receives transmitted light that has passed through a wafer. FIG. [Figure 6] FIG. 1 is a schematic diagram showing a state (1) when a wafer is transported on a ventilation block. [Figure 7] FIG. 10 is a schematic diagram showing a state (2) when wafers are transported on the ventilation block. [Figure 8] FIG. 10 is an explanatory diagram for explaining twin defects that appear at predetermined positions relative to the notch. [Figure 9] FIG. 9 is an explanatory diagram for explaining twin defects that appear at positions different from those in FIG. 8. [Figure 10] FIG. 10 is an explanatory view for explaining a transfer unit of another embodiment that transfers wafers in one direction. [Figure 11] FIG. 10 is an explanatory view for explaining a transfer unit of another embodiment for transferring wafers in another direction. [Figure 12] FIG. 10 is an explanatory diagram showing an example in which the wafer passes through the inspection information acquisition section while only the contact portion on the upstream side in the moving direction is in contact, and the contact portion on the downstream side in the moving direction is in contact before the wafer stops at the initial position and the return position. DETAILED DESCRIPTION OF THE INVENTION

[0011] A wafer inspection apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In the following description, the same components are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0012] (1) Overview of wafer inspection equipment 1 shows the overall configuration of a wafer inspection apparatus 11. Here, the following description will take as an example an unpatterned wafer that has been enlarged in diameter and thinned to produce a large number of semiconductors as the wafer 10 to be inspected by the wafer inspection apparatus 11. In addition, in this embodiment, the following description will take as an example a wafer inspection apparatus 11 that detects defects that exist inside the wafer 10 and are not visible from the front and back surfaces of the wafer 10, such as twin defects. Note that, for convenience of explanation, the surface located above the wafer 10 will be referred to as the front surface, and the surface located below will be referred to as the back surface.

[0013] 1, the wafer inspection device 11 includes a stage 13, a transport unit 14, an inspection information acquisition unit 15, and a detection unit 16. In this embodiment, the configuration consisting of the stage 13 and the transport unit 14, excluding the inspection information acquisition unit 15 and the detection unit 16, is referred to as the wafer transport device.

[0014] The stage 13 includes a plurality of ventilation blocks 18, a base 19 on which the ventilation blocks 18 are mounted, an exhaust unit 33 that supplies air to the ventilation blocks 18 and exhausts the air from the ventilation blocks 18, and an intake unit 34 that draws air through the ventilation blocks 18. The stage 13 includes a plurality of ventilation blocks 18 regularly arranged on the base 19 and fixed to the base 19. The ventilation blocks 18 have the same configuration and are formed of a porous material, such as porous carbon, having a plurality of ventilation holes 32, allowing air to pass through. As shown in FIG. 1 , the ventilation block 18 according to this embodiment has a rectangular shape whose length in the X direction, which is the transport direction of the wafer 10 in the wafer inspection device 11, is longer than its length in the Y direction, which is the width direction of the wafer inspection device 11. The ventilation blocks 18 are arranged in a matrix in the X and Y directions at predetermined intervals. The Z direction shown in FIG. 1 is the height direction perpendicular to the X and Y directions.

[0015] In addition, the ventilation block 18 is connected to an exhaust unit 33 having an exhaust pump or a compressed gas cylinder, etc., and also to an intake unit 34 having a vacuum pump, etc. The ventilation block 18 is configured so that air can be exhausted to the outside from the transport surface 20, which is the upper surface on which the wafers 10 are placed, by supplying air from the exhaust unit 33. The ventilation block 18 is also configured so that air can be sucked from the outside through the transport surface 20 by sucking air from the intake unit 34. In this way, the ventilation block 18 exhausts air from the transport surface 20 toward the back surface of the wafer 10, and sucks in air between the transport surface 20 and the back surface of the wafer 10, thereby adjusting the pressure between the transport surface 20 and the back surface of the wafer 10 and horizontally levitating the wafer 10 above the transport surface 20.

[0016] In this case, the ventilation block 18 has a configuration in which a plurality of exhaust holes 35 that discharge air toward the back surface of the wafer 10 and a plurality of intake holes 37 that draw air between the back surface of the wafer 10 are formed as ventilation holes 32 on the transport surface 20, an exhaust section 33 is connected to each exhaust hole 35, and an intake section 34 is connected to each intake hole 37. The number of intake holes 37 is fewer than the number of exhaust holes 35, and they are provided at positions on the transport surface 20 that are different from the exhaust holes 35.

[0017] The exhaust holes 35 provided in the ventilation block 18 exhaust air from the transfer surface 20 to the backside of the wafer 10, thereby increasing the pressure between the wafer 10 and the transfer surface 20 and causing the wafer 10 to float above the transfer surface 20. On the other hand, the intake holes 37 suck air from the transfer surface 20, thereby reducing the pressure between the wafer 10 and the transfer surface 20 and generating negative pressure, which sucks the wafer 10 toward the transfer surface 20. As a result, the exhaust and intake of the exhaust holes 35 and the intake holes 37 are adjusted by the control of the exhaust unit 33 and the intake unit 34, and the wafer 10 continues to be stably and horizontally floated above the transfer surface 20.

[0018] The transport unit 14 is configured to transport the wafer 10, which has been horizontally levitated by the ventilation block 18, between an initial position 21 and a return position 22 while maintaining the horizontally levitated state (hereinafter also referred to as "horizontal transport"). In the wafer inspection device 11, the initial position 21 and the return position 22 are predetermined on the stage 13, and in the following description, the linear direction from the initial position 21 to the return position 22 will be referred to as one direction, and the linear direction from the return position 22 to the initial position 21, which is the opposite direction to the one direction, will be referred to as the other direction. In FIG. 1, the one direction and the other direction are directions along the X direction.

[0019] The transport unit 14 includes a pair of guide rails 24 provided on the stage 13, a transport frame 29 that is movable along the guide rails 24, a plurality of abutment portions 25, 26, 27, and 28 provided on the transport frame 29, and a drive unit 30 that moves the transport frame 29 along the guide rails 24. The pair of guide rails 24 extend parallel to each other in the X direction on both sides of an area on the stage 13 where the plurality of ventilation blocks 18 are arranged, and the transport frame 29 is configured to be slidably mounted thereon.

[0020] The transport frame 29 has a picture-frame-shaped frame 29b having a hollow ventilation opening 29a in its central region, and is formed so that the ventilation block 18 is exposed within the ventilation opening 29a. The frame 29b is formed to a size that allows the wafer 10 to be placed within the hollow region of the ventilation opening 29a, and the wafer 10 can be horizontally floated within the hollow region of the ventilation opening 29a by adjusting the air with the ventilation block 18.

[0021] In addition, the frame portion 29b is provided around the ventilation opening 29a with a plurality of contact portions 25 to 28 that can come into contact with the outer periphery of the wafer 10 that is horizontally floated above the ventilation block 18 by air. Further, a drive unit 30 is connected to the frame portion 29b according to this embodiment, and a drive force is applied from the drive unit 30. As a result, the frame portion 29b slides in the X direction along the guide rail 24 based on the drive force from the drive unit 30.

[0022] The contact portions 25-28 are composed of first contact portions 25, 26 that can contact one outer peripheral edge of the wafer 10, and second contact portions 27, 28 that are arranged opposite the first contact portions 25, 26 in the X direction across the wafer 10 and can contact the other outer peripheral edge of the wafer 10. Note that, here, when there is no particular need to distinguish between the first contact portions 25, 26 and the second contact portions 27, 28, they will be simply referred to as the contact portions 25-28. Furthermore, in this embodiment, the side on which the first contact portions 25, 26 are arranged will be referred to as the rear side of the wafer 10, and the side on which the second contact portions 27, 28 are arranged will be referred to as the front side of the wafer 10. In this example, of the outer peripheral edge of the wafer 10, the portion on the initial position 21 side of a diameter parallel to the Y direction passing through the center of the wafer 10 is one outer peripheral edge, and the portion on the return position 22 side is the other outer peripheral edge.

[0023] In this case, when air is exhausted and sucked by the ventilation block 18 so that the wafer 10 can float horizontally, and the wafer 10 is loaded onto the ventilation block 18 exposed within the ventilation opening 29a of the frame portion 29b at the initial position 21 by the supply / discharge unit 40 described later, the contact units 25-28 move upward from the backside of the wafer 10 or approach the outer periphery of the wafer 10 from the radial direction of the wafer 10, and move so as to abut against the outer periphery of the horizontally floating wafer 10. Furthermore, when the horizontally floating wafer 10 after inspection by the inspection information acquisition unit 15 described later is unloaded by the supply / discharge unit 40 at the initial position 21, the contact units 25-28 move downward from the backside of the wafer 10 or move away from the wafer 10 in the radial direction of the wafer 10, and are thus out of contact with the wafer 10 and move so as not to interfere with the unloading of the horizontally floating wafer 10.

[0024] Because the contact portions 25 to 28 are fixed to the transport frame 29, they move in the X direction together with the transport frame 29 as the transport frame 29 moves in the X direction along the guide rails 24. The contact portions 25 to 28 come into contact with the outer periphery of the wafer 10 floating horizontally above the ventilation block 18, and as the transport frame 29 moves in one direction, the contact portions 25 to 28 push the wafer 10 in one direction while keeping it floating horizontally, moving the wafer 10 from the initial position 21 to the return position 22. As a result, the wafer 10 passes through the inspection information acquisition unit 15 on the transport path between the initial position 21 and the return position 22.

[0025] Furthermore, after the transport frame 29 has moved the wafer 10 to the return position 22, it moves in the other direction while keeping the contact portions 25-28 in contact with the outer periphery of the horizontally levitated wafer 10. As a result, the contact portions 25-28 push the wafer 10 in the other direction while keeping it horizontally levitated, and move the wafer 10 from the return position 22 to the initial position 21. The initial position 21 is a position where the wafer 10 is loaded or unloaded. The return position 22 is a completion position where the wafer 10 has been moved in one direction and has passed through the inspection information acquisition unit 15.

[0026] The first contact portions 25, 26 according to this embodiment are arranged symmetrically about the central axis, with one direction (X direction passing through the center) passing through the center of the wafer 10 in a plan view as the central axis, so that when they contact one outer peripheral edge of the wafer 10 at the initial position 21 to move the wafer 10 in one direction, a uniform force is applied to one outer peripheral edge of the wafer 10. Similarly, the second contact portions 27, 28 are arranged symmetrically about the central axis, with the other direction (X direction passing through the center) passing through the center of the wafer 10 in a plan view as the central axis, so that when they contact the other outer peripheral edge of the wafer 10 at the return position 22 to move the wafer 10 in the other direction, a uniform force is applied to the other outer peripheral edge of the wafer 10. The number of contact portions 25-28 is not limited to four and may be five or more as long as they can press the wafer 10 with the same force.

[0027] FIG. 2 shows the initial position 21 of the wafer 10. In this embodiment, an inspection information acquisition unit 15 (described later) is installed between ventilation blocks (denoted by reference numerals 18a and 18b in FIG. 2) adjacent in the X direction, which are provided between the initial position 21 and the return position 22. In the following description, the ventilation blocks 18 adjacent in the X direction are denoted by reference numerals 18a and 18b when particularly distinguishing between them. As shown in FIG. 2, a supply / discharge position 39 is provided outside the stage 13. The supply / discharge position 39 is provided with a supply / discharge unit 40 for loading and unloading the wafer 10. The supply / discharge unit 40 loads the wafers 10 one by one from the supply / discharge position 39 to the initial position 21. The wafer 10 is set at the initial position 21 so that a notch 41 provided at a predetermined position on its outer periphery is positioned at a predetermined position.

[0028] After the wafer 10 has been moved from the initial position 21 to the return position 22 and the inspection has been completed, the wafer 10 is returned from the return position 22 to the initial position 21 again. When the supply / discharge unit 40 returns from the return position 22 to the initial position 21 again, the supply / discharge unit 40 unloads the wafer 10 from the initial position 21 after the inspection has been performed again. The loading and unloading direction of the supply / discharge unit 40 is, for example, the Y direction which is perpendicular to the one direction.

[0029] The contact portions 25 to 28 according to this embodiment are provided at their tips with holding portions 43, 44, 45, and 46, each having a U-shaped cross section and an open portion. In this embodiment, for example, each of the holding portions 43 to 46 is movable between a contact position where it contacts the outer periphery of the wafer 10 located at the initial position 21 and a retracted position where it moves away from the contact position radially outward from the outer periphery of the wafer 10.

[0030] When the wafer 10 is set in the initial position 21, the holders 43 to 46 move from the retracted positions to the contact positions. At the contact positions, the outer periphery of the wafer 10 slightly enters the openings of the holders 43 to 46, but the contact area with the outer periphery of the wafer 10 is minimized. When the transport frame 29 moves in one direction or the other, the holders 43 to 46 simply touch the outer periphery of the horizontally levitated wafer 10 and push it, thereby transporting the horizontally levitated wafer 10 while keeping it horizontally levitated. In this way, when transporting the wafer 10, it is sufficient that the holders 43 and 44 (first contact portions 25 and 26) or the holders 45 and 46 (second contact portions 27 and 28) on the upstream side pushing the wafer 10 in the transport direction (one direction or the other direction) contact the outer periphery of the wafer 10 and push it in the transport direction. Therefore, the holding portions 43 to 46 may be configured not only to fit the outer periphery of the wafer 10, but also to simply come into contact with the outer periphery of the wafer 10.

[0031] The base 19 is formed with four holes 48, each accommodating a rod-shaped arm (not shown) that can protrude from between the ventilation blocks 18 along the height direction Z. When the arm does not protrude from the hole 48, the tip of the arm is in a position (retracted position) lower than the transport surface 20 of the ventilation block 18, and when the arm protrudes from the hole 48, the tip is in a position (push-up position) higher than the transport surface 20, and the arm raises and lowers the wafer 10 at the initial position 21 as needed.

[0032] In this case, first, the wafer 10 is placed at the initial position 21 by the supply / discharge unit 40, and then the arm protrudes from the hole 48 through the ventilation block 18 to a position higher than the transfer surface 20, thereby raising the wafer 10. The arm then receives the wafer 10 from the supply / discharge unit 40. During this time, air is being exhausted and sucked into the ventilation block 18, applying pressure to the wafer 10 to lift it horizontally. After that, the supply / discharge unit 40 moves from the supply / discharge position 39, and the arm descends and retreats to the hole 48. The wafer 10 supported by the arm is then maintained at the initial position 21, horizontally levitated above the transfer surface 20 by air. Then, the holding portions 43-46 of the abutting portions 25-28 move to the contact positions and abut against the outer periphery of the wafer 10. Then, when the drive unit 30 moves the transport frame unit 29 from the initial position 21 to the return position 22, i.e., in one direction, the wafer 10 abutting against the abutment units 25 to 28 of the transport frame unit 29 also moves from the initial position 21 to the return position 22.

[0033] FIG. 3 shows the return position 22 of the wafer 10. The inspection information acquisition unit 15 is disposed between the initial position 21 and the return position 22 of the wafer 10. As a result, when the wafer 10 moves in one direction from the initial position 21 toward the return position 22, the wafer 10 passes through the opening 57 of the opening formation unit 15a of the inspection information acquisition unit 15. When the wafer 10 passes through the opening 57 of the opening formation unit 15a, the inspection information acquisition unit 15 irradiates the front surface of the wafer 10 with irradiation light extending linearly in the Y direction, receives the transmitted light that is transmitted from the back surface of the wafer 10, and outputs the obtained light reception result (light information) to the detection unit 16. As a result, the detection unit 16 inspects the wafer 10 for defects based on the light reception result received as inspection information. When inspecting for twin defects as defects, for example, the crossed Nicols method is used to detect a change in birefringence due to the photoelastic effect of twin defects from a change in the phase of the transmitted light.

[0034] Next, the configuration of the inspection information acquisition unit 15 will be described. As shown in Fig. 4, the inspection information acquisition unit 15 includes an opening formation unit 15a, a light source group 53, and a light receiving unit group 55. The opening formation unit 15a is formed in a frame shape and is fixed to a base 19. The opening formation unit 15a has an opening 57 formed therein through which the horizontally levitated wafer 10, which is moved in one direction and the other by the transport unit 14, and the transport frame 29, which moves in one direction and the other together with the wafer 10, can pass. In the opening formation unit 15a, the light source group 53 and the light receiving unit group 55 are arranged opposite each other in the Z direction with the opening 57 in between.

[0035] In this embodiment, a light source group 53 is installed above an opening 57 of the opening formation portion 15a, and a light receiving group 55 capable of receiving light emitted from the light source group 53 is installed below the opening 57. The light source group 53 is composed of multiple light sources 53a to 53k, and the light receiving group 55 is composed of the same number of light receiving units 55a to 55k as the light sources 53a to 53k. When the horizontally floating wafer 10 passes through the opening 57, the light source group 53 irradiates the surface of the wafer 10 with light from each of the light sources 53a to 53k. At this time, the wafer 10 is horizontally floated by air, and does not warp or bend, and is maintained approximately horizontal from the center to the outer periphery. Therefore, the light source group 53 can irradiate light in the direction of a surface normal perpendicular to the surface of the wafer 10 (height direction Z).

[0036] In the light-receiving unit group 55, the light-receiving units 55a to 55k receive transmitted light, which is irradiated light passing through the wafer 10 perpendicularly to the surface of the wafer 10, and output the light-receiving results obtained for each of the light-receiving units 55a to 55k to the detection unit 16. Fig. 5 shows the reading range of the light-receiving unit group 55, and the specific arrangement positions of the light sources 53a to 53k and the light-receiving units 55a to 55k will be described below using Fig. 5. Note that the light sources 53a to 53k and the light-receiving units 55a to 55k are arranged opposite each other in the Z direction, and therefore the following description will focus on the positions of the light-receiving units 55a to 55k.

[0037] 5, the light receiving units 55a to 55k are arranged to face the corresponding light sources 53a to 53k in the Z direction, respectively, and are arranged in a staggered pattern in two rows along the Y direction, which is perpendicular to the direction (X direction) in which the wafer 10 moves. Specifically, a first row of light receiving units 55a to 55e is arranged in a row along the Y direction at a predetermined interval, and a second row of light receiving units 55f to 55k is also arranged in a row along the Y direction at a predetermined interval, and the rows are shifted by a distance B in the X direction. In FIG. 5, the symbol A indicates the light receiving width of the transmitted light at the first row of light receiving units 55a to 55e, and the symbol C indicates the light receiving width of the transmitted light at the second row of light receiving units 55f to 55k.

[0038] The light receiving portions 55a-55e in the first row are arranged so as to fill in the unirradiated regions formed between the adjacent light receiving portions 55f-55k in the second row. The light receiving portion group 55 can receive transmitted light from the entire Y direction of the wafer 10 using the light receiving portions 55a-55e in the first row and the light receiving portions 55f-55k in the second row. In this way, as the wafer 10 passes through the opening 57, the light receiving portions 55a-55e continuously receive transmitted light that has passed through the wafer 10 from the outer circumferential edge on the front side to the outer circumferential edge on the rear side, thereby receiving transmitted light from the entire surface of the wafer 10.

[0039] 5, in this embodiment, the regions in the first row of light receiving units 55a to 55e that receive transmitted light and the regions in the second row of light receiving units 55f to 55k that receive transmitted light are arranged so that they do not overlap in the X direction and can receive transmitted light continuously in the Y direction, but the present invention is not limited to this, and for example, the regions in the first row of light receiving units 55a to 55e that receive transmitted light and the regions in the second row of light receiving units 55f to 55k that receive transmitted light may be arranged to overlap in the X direction. In this case, the detection unit 16 may delete data from either one of the regions where the regions in the first row of light receiving units 55a to 55e that receive transmitted light and the regions in the second row of light receiving units 55f to 55k that receive transmitted light overlap, thereby obtaining a light receiving result similar to that obtained when transmitted light is received continuously in the Y direction.

[0040] The detection unit 16 detects defects inside the wafer 10 based on the intensity of the transmitted light obtained from the light receiving units 55a to 55k. At this time, the detection unit 16 detects the presence or absence of defects in the wafer 10 based on the transmitted light that is transmitted perpendicularly to the surface of the wafer 10. Therefore, various defects such as twin defects inside the wafer 10 can be detected more accurately without being affected by warpage or bending that occurs in the wafer 10.

[0041] In this embodiment, inspection is performed on the wafer 10 that passes the inspection information acquisition unit 15 when the wafer 10 moves in one direction from the initial position 21 to the return position 22, and then inspection is also performed on the wafer 10 that passes the inspection information acquisition unit 15 when the wafer 10 moves in the other direction from the return position 22 back to the initial position 21. Note that the inspection information acquisition unit 15 may inspect the wafer 10 for defects only when the wafer 10 moves in one direction from the initial position 21 to the return position 22, or may inspect the wafer for defects only when the wafer 10 moves in the other direction from the return position 22 to the initial position 21.

[0042] Here, the inspection information acquisition unit 15 is disposed between the ventilation blocks 18a and 18b adjacent to each other in the X direction. Therefore, at the location where the inspection information acquisition unit 15 is installed, a space in which the light source group 53 and the light receiving unit group 55 can be disposed needs to be formed between the ventilation blocks 18a and 18b. Therefore, as shown in FIG. 6, the exhaust unit 33 and the intake unit 34 adjust the exhaust and intake of air so that the pressure is uniform even between the ventilation blocks 18a and 18b in the gap between the ventilation blocks 18a and 18b where the inspection information acquisition unit 15 (not shown in FIG. 6) is installed, so that the wafer 10 passes between the ventilation blocks 18a and 18b without being deformed by its own weight and while remaining horizontally levitated.

[0043] The amounts of air exhaust and intake from the ventilation blocks 18a, 18b are adjusted, or the positions, number, and sizes of the exhaust holes 35 and intake holes 37 are adjusted, so that the exhaust of air from the exhaust holes 35 applies positive pressure to the space between the wafer 10, and the intake of air from the intake holes 37 applies negative pressure to the space between the wafer 10. As a result, the wafer 10 maintains a uniformly horizontally levitated state without uneven load due to the fluid film formed on each transfer surface 20 of the ventilation blocks 18a, 18b and along the space above the ventilation blocks 18a, 18b by adjusting the positive and negative pressure.

[0044] The movement of the wafer 10 between the ventilation blocks 18a, 18b is made smooth by the effect of the preload applied by the negative pressure. In other words, without applying negative pressure, the outer edge of the wafer 10a may bend, as shown by the dotted line in Figure 6. Therefore, by drawing the wafer 10 toward the transfer surface 20 using air intake through the intake holes 37, the rigidity of the fluid film is increased, and bending of the wafer 10 that occurs when the wafer 10 moves between the ventilation blocks 18a, 18b can be suppressed.

[0045] 7, even when a wafer 10 that is thin and easily deformed by its own weight passes between widely spaced ventilation blocks 18a and 18b, the effect of the preload makes it possible to precisely maintain the planar state of the wafer 10 and horizontally levitate the wafer 10. By applying a negative preload, displacement or vibration in the Z direction (height direction) to the wafer 10 becomes less likely to occur, and for example, it is possible to prevent the wafer 10b from becoming wavy, as shown by the dotted line in FIG.

[0046] Next, a method for positioning the wafer 10 to facilitate detection of twin defects formed in the wafer 10 by the wafer inspection apparatus 11 will be described below. FIG. 8 shows an example of a wafer 10 in which twin defects 59 are likely to be formed at a position at a predetermined angle relative to the notch 41. In this wafer 10, twin defects 59 extending radially from the center O of the wafer 10 toward the outer periphery are formed around the outer periphery at a position at a predetermined angle relative to the notch 41. When inspecting the presence or absence of twin defects 59 on a wafer 10 in which the locations where twin defects 59 are likely to occur can be predicted using the notch 41 as a guide, using the wafer inspection apparatus 11 according to this embodiment, it is desirable to determine the positioning direction of the wafer 10 at the initial position 21 using the position of the notch 41 as a guide so that the twin defects 59 can be easily detected by the inspection information acquisition unit 15.

[0047] That is, in this example, it is desirable that wafer 10 be placed at initial position 21 of stage 13 so that reference line 60, which passes through the formation position of notch 41 of wafer 10 and center O, coincides with one direction (X direction) that is the movement direction of wafer 10. When wafer 10 is placed at initial position 21 in such a direction using the position of notch 41 as a guide, wafer 10, which has been horizontally levitated by holders 43 to 46, is pushed in one direction and passes through inspection information acquisition unit 15 without rotating.

[0048] In this case, the twin defect 59 is arranged so that, in a plan view, it extends in the Y direction perpendicular to one direction (X direction) that is the movement direction when the wafer 10 passes through the inspection information acquisition unit 15, and is positioned at an angle θ1 (for example, 45 degrees) with respect to an orthogonal line 61 that passes through the center O of the wafer 10. As a result, in the wafer inspection device 11, the twin defect 59 is at an angle close to the angle θ1 with respect to the irradiation line (Y direction) of the irradiation light irradiated by the inspection information acquisition unit 15, making it easier to detect the twin defect 59 from the light reception results.

[0049] 9 shows an example in which a twin defect 59 is formed at another position on the wafer 10. FIG. 9 shows an example of a wafer 10 in which a twin defect 59 extending from a predetermined position on the wafer 10 toward the outer periphery is likely to be formed around the outer periphery at a predetermined angle relative to the notch 41. A wafer 10 in which such a twin defect 59 is likely to be formed is arranged so that, in a plan view, the twin defect 59 extends in a Y direction perpendicular to one direction (X direction) in which the wafer 10 moves when passing through the inspection information acquisition unit 15, and is positioned at an angle of −θ1 (for example, −45 degrees) (the angle between the orthogonal line 61 and the extension direction of the twin defect 59) with respect to an orthogonal line 61 passing through the center O of the wafer 10. As a result, in the wafer inspection device 11, the twin defect 59 is at an angle close to the angle −θ1 with respect to the irradiation line (Y direction) of the irradiation light irradiated by the inspection information acquisition unit 15, making it easier to detect the twin defect 59 from the light reception results.

[0050] (2) Action and effect In the above configuration, the wafer inspection apparatus 11 levitates the wafer 10 horizontally above the ventilation block 18 by discharging air from the ventilation block 18 on which the wafer 10 is placed toward the surface of the wafer 10. The transport unit 14 then moves the wafer 10 in one direction by using the drive unit 30 to move the contact units 25 to 28 relative to the ventilation block 18, and passes the wafer 10 while still levitated horizontally through the inspection information acquisition unit 15. As a result, when the wafer 10 passes through the inspection information acquisition unit 15, the wafer inspection apparatus 11 can acquire a light reception result as inspection information for the wafer 10 using the inspection information acquisition unit 15, and the detection unit 16 can detect defects in the wafer 10 based on the light reception result.

[0051] In this way, in the wafer inspection device 11, the wafer 10 is horizontally levitated by air, thereby suppressing the occurrence of warping or bending of the wafer 10. Therefore, when inspecting the wafer 10 for defects, the influence of warping or bending of the wafer 10 is reduced, and defects in the wafer 10 can be detected more accurately than before.

[0052] Furthermore, the transport unit 14 abuts the first contact portions 25, 26 against one outer peripheral edge of the wafer 10 and moves the first contact portions 25, 26 relative to the stage 13 using the drive unit 30, thereby moving the wafer 10 in one direction while keeping it horizontally levitated, and causes the wafer 10 to pass through the inspection information acquisition unit 15 (first transport operation). Furthermore, after the wafer 10 has passed through the inspection information acquisition unit 15 by the first transport operation, the transport unit 14 abuts the second contact portions 27, 28 against the other outer peripheral edge of the wafer 10 and moves the second contact portions 27, 28 relative to the stage 13 using the drive unit 30, thereby moving the wafer 10 in the other direction opposite to the one direction while keeping it horizontally levitated, and causes the wafer 10 to pass through the inspection information acquisition unit 15 again (second transport operation). In this way, by performing the first transport operation and the second transport operation, the wafer inspection device 11 passes the wafer 10 through the inspection information acquisition unit 15 twice, and each time inspects the wafer 10 for defects, thereby enabling accurate detection of defects in the wafer 10.

[0053] Furthermore, in the wafer inspection apparatus 11, the wafer 10 can be simply passed between a plurality of light sources 53a to 53k and a plurality of light receiving units 55a to 55k arranged in a line along a direction perpendicular to one direction in which the wafer 10 moves, and the transmitted light that has passed through the wafer 10 can be received, and defects in the wafer 10 can be detected based on the obtained light receiving results. As a result, the wafer inspection apparatus 11 of this embodiment can improve throughput during defect inspection of the wafer 10 compared to, for example, a conventional wafer inspection apparatus in which a pair of light sources and a light receiving unit are moved in the radial direction relative to the rotating wafer and transmitted light that has passed through the wafer is received at this time to detect wafer defects.

[0054] (3) Other embodiments In the above-described embodiment, when the horizontally levitated wafer 10 is moved in one direction and the other direction, all four holders 43 to 46 are brought into contact with the outer periphery of the wafer 10, and the wafer 10 is moved by the four holders 43 to 46. However, the present invention is not limited to this. For example, as shown in Fig. 10, when the wafer 10 is moved in one direction, only the holders 43 and 44 located on the rear side of the wafer 10 may be brought into contact with the wafer 10, and the remaining holders 45 and 46 located on the front side of the wafer 10 may be kept out of contact with the wafer 10, so that the wafer 10 is pushed and moved in one direction by only the holders 43 and 44.

[0055] In this case, when the wafer 10 passes through the inspection information acquisition unit 15, the holding units 45, 46 are not in contact with the wafer 10, so the outer periphery of the wafer 10 can be exposed without being hidden by the holding units 45, 46. This allows the inspection information acquisition unit 15 to irradiate the irradiation light to areas of the wafer 10 that are not in contact with the holding units 45, 46, thereby reducing the number of areas that remain uninspected.

[0056] 11 , when moving the wafer 10 in the other direction, only the holders 45 and 46 located on the front side of the wafer 10 may be brought into contact with the wafer 10, while the remaining holders 43 and 44 located on the rear side of the wafer 10 are not brought into contact with the wafer 10, and the wafer 10 may be pushed and moved in the other direction by the holders 45 and 46 alone. As described above, this allows the inspection information acquisition unit 15 to irradiate the portions of the wafer 10 that are not in contact with the holders 43 and 44, thereby reducing the number of uninspected areas. In this way, by changing the holders 43 to 46 that come into contact with the wafer 10 depending on the direction of movement of the wafer 10, data on the entire surface of the wafer 10 can be acquired through two inspections, one when moving from the initial position 21 to the return position 22 and the other when moving from the return position 22 to the initial position 21.

[0057] Here, if the wafer 10 is sandwiched between the holders 43, 44 and the holders 45, 46 as described above, stress may be generated in the wafer 10 by the holders 43 to 46. When the wafer inspection device 11 detects crystal defects such as twin defects by measuring changes in birefringence of the wafer 10 due to the photoelastic effect, if the above-described stress is generated in the wafer 10, it may be difficult to detect the crystal defects in the stressed portion. However, in this embodiment, while the wafer 10 passes through the inspection information acquisition unit 15 (the irradiation line of the irradiation light), only the contact portion upstream of the wafer 10 in the transport direction (upstream of the movement direction) contacts the wafer 10, and the wafer 10 is pushed and moved by the contact portion. That is, when the wafer 10 is moved in one direction, only the holders 43, 44 of the first contact portion contact the wafer 10, and when the wafer 10 is moved in the other direction, only the holders 45, 46 of the second contact portion contact the wafer 10, and the wafer 10 is pushed and moved. This prevents stress from being generated in the wafer 10 due to the wafer 10 being sandwiched between the holders 43, 44 and the holders 45, 46. Therefore, when detecting twin defects in the wafer 10, the stress of the wafer 10 can be prevented from affecting the detection.

[0058] In this embodiment as well, it is not essential that the holding portions 43 to 46 penetrate the outer peripheral edge of the wafer 10, and as described above, the holding portions 43, 44 (first contact portions 25, 26) or the holding portions 45, 46 (second contact portions 27, 28) may simply come into contact with the outer peripheral edge of the wafer 10 and push it in the movement direction without penetrating the outer peripheral edge of the wafer 10. Furthermore, by reciprocating the wafer 10 between the initial position 21 and the return position 22, the entire surface of the wafer 10 can be inspected twice, and data for the entire surface of the wafer 10 can be obtained in each of the two inspections.

[0059] As described above, when the wafer 10 is moved by bringing only the contact portion on the upstream side in the transport direction into contact with the wafer 10 while the wafer 10 passes through the inspection information acquisition unit 15, when the movement is stopped, it is preferable to bring the contact portion on the downstream side in the transport direction (downstream in the movement direction) of the wafer 10 into contact with the wafer 10 before stopping the wafer 10.

[0060] 12 shows an example in which the contact portions downstream of the wafer 10 in the transport direction are brought into contact with the wafer 10 before the wafer 10 is stopped as described above. In this example, when the wafer 10 is loaded at the initial position 21, the holding portions 43-46 of the contact portions 25-28 move to the contact positions and come into contact with the outer periphery of the wafer 10 (step 1201). As the transport frame 29 moves in one direction, the wafer 10 starts to be transported from the initial position 21 toward the return position 22 while the holding portions 43-46 remain in contact with the wafer 10. That is, the wafer 10 is stopped at the initial position 21 with both the first contact portions 25, 26 and the second contact portions 27, 28 in contact with the wafer 10, and then starts to move from this stopped state, with both the first contact portions 25, 26 and the second contact portions 27, 28 still in contact with the wafer 10 at the start of the movement.

[0061] During the movement of the wafer 10, before the wafer 10 reaches the inspection information acquisition unit 15 (i.e., before the outer periphery on the front side of the wafer 10 reaches the irradiation line of the irradiation light), the holding units 45, 46 of the second abutment units 27, 28 downstream of the wafer 10 in the transport direction are set to the retracted position so as to be out of contact with the wafer 10 (step 1202). The timing for setting the holding units 45, 46 to the retracted position may be, for example, just before the outer periphery on the front side of the wafer 10 reaches the irradiation line, or just after the wafer 10 starts to move toward the return position, or may be an intermediate position therebetween.

[0062] As a result, the wafer 10 passes through the inspection information acquisition unit 15 (the irradiation line of the irradiation light) with the holding units 45, 46 in the retracted positions (steps 1203, 1204). That is, the wafer 10 passes through the inspection information acquisition unit 15 while being pressed by only the holding units 43, 44 of the first contact units 25, 26 located upstream in the transport direction.

[0063] After the wafer 10 passes the inspection information acquisition unit 15, before it reaches the return position 22 (i.e., before the one-way movement of the wafer 10 is stopped), the holding portions 45, 46 of the second contact portions 27, 28 are brought into contact with the wafer 10 at the contact positions (step 1205). Then, with both the holding portions 43, 44 of the first contact portions 25, 26 and the holding portions 45, 46 of the second contact portions 27, 28 in contact with the wafer 10, the wafer 10 is transported to the return position 22, at which point the transport is stopped.

[0064] When the wafer 10 is subsequently transported in the other direction (i.e., from the return position 22 toward the initial position), the movement of the wafer 10 begins with the holding portions 43-46 of the contact portions 25-28 in the contact position. During this movement in the other direction, before the wafer 10 reaches the inspection information acquisition unit 15, the holding portions 43-44 of the first contact portions 25-26 are moved to the retracted position and put into a non-contact (non-contact) state with respect to the wafer 10. As a result, the wafer 10 passes through the inspection information acquisition unit 15 with only the holding portions 45-46 of the second contact portions 27-28 in contact with the outer periphery thereof and being pushed by them. After the wafer 10 passes the inspection information acquisition unit 15, before it reaches the initial position 21 (i.e., before the wafer 10 stops moving in the other direction), the holding portions 43-44 of the first contact portions 25-26 are moved to the contact position and put into a contact (contact) state with respect to the wafer 10. Then, the wafer 10 is stopped at the initial position 21 with both the holding portions 43, 44 of the first contact portions 25, 26 and the holding portions 45, 46 of the second contact portions 27, 28 in contact with the wafer 10.

[0065] As described above, before stopping the movement of the wafer 10 at the return position 22 or the initial position 21, the first contact portions 25, 26 and the second contact portions 27, 28, which are arranged opposite each other via the wafer 10, are brought into contact with the wafer 10. This allows the contact portions 25 to 28 to come into contact with each other while the posture of the wafer 10 is stabilized, i.e., without the wafer 10 moving in the Y direction or rotating about an axis in the Z direction, and the movement of the wafer 10 is stopped in this state.

[0066] In this example, the return position 22 is set to a position where the wafer 10 reaches after passing the inspection information acquisition unit 15 when the wafer 10 is moved in one direction. Similarly, the initial position 21 is set to a position where the wafer 10 reaches after passing the inspection information acquisition unit 15 when the wafer 10 is moved in the other direction. In this example, the contact portions 25-28 are configured to simply contact the outer periphery of the wafer 10 without covering the front and back surfaces of the wafer 10. For example, the contact portions 25-28 have cylindrical holding portions 43-46 at their tips. These cylindrical holding portions 43-46 are each oriented such that their axial direction is in the thickness direction (Z direction) of the wafer 10, and their peripheral surfaces come into point contact with the outer periphery of the wafer 10.

[0067] Furthermore, in each of the above-described embodiments, a wafer inspection apparatus 11 for detecting defects on a wafer without a pattern (unpatterned wafer) 10 is described, but the present invention is not limited to this and may be applied to, for example, a wafer inspection apparatus for detecting defects on wafers at various stages, such as patterned wafers.

[0068] In the above-described embodiments, the wafer inspection apparatus 11 is described as inspecting the presence or absence of twin defects inside the wafer 10, but the present invention is not limited to this and may be applied to a wafer inspection apparatus that inspects the presence or absence of, for example, surface scratches and irregularity defects that are external defects of the wafer, crystal defects that exist only on the surface of the wafer, and defects that exist only inside the wafer and are not visible from the front or back surface of the wafer. In this case, the inspection information acquisition unit is changed depending on the type of defect to be inspected, and an inspection information acquisition unit that can acquire inspection information that can detect the presence or absence of the desired defect is used.

[0069] In addition, in each of the above-described embodiments, the case has been described in which the inspection information acquisition unit 15 that acquires the light reception results of transmitted light obtained by irradiating the wafer 10 with irradiation light is used as the inspection information acquisition unit that acquires wafer inspection information, but the present invention is not limited to this. As other inspection information acquisition units, for example, an inspection information acquisition unit that irradiates the wafer 10 with irradiation light and acquires the light reception results of reflected light reflected from the surface of the wafer, or an inspection information acquisition unit that captures an image of the surface of the wafer 10 with an imaging unit such as a camera and acquires the captured image as inspection information may be used.

[0070] In the above-described embodiment, the exhaust holes 35 and intake holes 37 in the ventilation block 18 may be formed by mechanical processing. If the wafer 10 can be horizontally levitated only by exhausting air from the ventilation block 18, a ventilation block formed with only the exhaust holes 35 may be used. [Explanation of symbols]

[0071] 10 wafers 11 Wafer inspection equipment 13 Stages 14 Conveying section 15. Test information acquisition unit 16 Detector 18 Ventilation Block 25~28 Contact part 53a~53k light source 55a~55k Photoreceptor

Claims

1. A wafer inspection device that inspects wafers for defects, a stage on which the wafer is placed on a ventilation block, and which levitates the wafer horizontally above the ventilation block by discharging air from the ventilation block toward a surface of the wafer; a transport unit that transports the wafer horizontally levitated above the stage by air in one direction relative to the stage; an inspection information acquisition unit that acquires inspection information for the wafer; a detection unit that detects defects on the wafer based on the inspection information of the wafer acquired by the inspection information acquisition unit; Equipped with The conveying unit is a contact portion that contacts the outer periphery of the wafer that is horizontally levitated above the stage by air; a drive unit that moves the contact portion relative to the stage; the drive unit moves the contact unit relative to the stage to move the wafer in one direction, and the wafer passes through the inspection information acquisition unit while being horizontally levitated; The examination information acquisition unit acquiring inspection information for the wafer when the wafer passes; Wafer inspection equipment.

2. The ventilation block is the air vent block is formed of a porous material and has an exhaust hole for discharging air toward the surface of the wafer and an intake hole for drawing air between the ventilation block and the surface of the wafer, and the pressure between the ventilation block and the surface of the wafer is adjusted by exhausting air from the exhaust hole and drawing air from the intake hole, thereby horizontally floating the wafer above the ventilation block; 2. The wafer inspection apparatus according to claim 1.

3. The examination information acquisition unit a plurality of light sources arranged along a direction perpendicular to one direction in which the wafer moves; a plurality of light receiving units arranged to face the light source along a direction perpendicular to the one direction in which the wafer moves; Equipped with The light receiving unit When the wafer passes between the light source and the light receiving unit, the light receiving unit receives transmitted light that has passed through the wafer as a result of irradiation light being irradiated onto the wafer from the light source, and outputs the obtained light receiving result to the detection unit as the inspection information.

2. The wafer inspection apparatus according to claim 1.

4. The stage includes: A plurality of the ventilation blocks are provided, The examination information acquisition unit an opening forming portion provided between adjacent ventilation blocks and having an opening through which the wafer moving in one direction can pass; The opening forming portion has The plurality of light sources and the plurality of light receiving units are arranged to face each other with the opening therebetween.

4. The wafer inspection apparatus according to claim 3.

5. The abutment portion is a plurality of first contact portions that contact one outer peripheral edge of the wafer; a plurality of second contact portions disposed opposite the plurality of first contact portions across the wafer and contacting the other outer peripheral edge of the wafer; Equipped with The conveying unit is a first conveying operation in which the plurality of first contact portions are brought into contact with one outer peripheral edge of the wafer and the driving unit moves the plurality of first contact portions relative to the stage, thereby moving the wafer in one direction while keeping it horizontally levitated, and causing the wafer to pass through the inspection information acquisition unit; a second transport operation in which, after the wafer has passed through the inspection information acquisition unit by the first transport operation, the plurality of second contact portions are brought into contact with the other outer peripheral edge of the wafer and the plurality of second contact portions are moved relative to the stage by the drive unit, thereby moving the wafer in another direction opposite to the one direction while keeping it horizontally levitated, and causing the wafer to pass through the inspection information acquisition unit again; The wafer inspection device of claim 1 , wherein the wafer inspection device performs the following steps:

6. In the first transport operation, the plurality of second contact portions are not in contact with the wafer at least while the wafer passes through the inspection information acquisition unit; In the second transport operation, the plurality of first contact portions are not in contact with the wafer at least while the wafer passes through the inspection information acquisition unit; 6. The wafer inspection apparatus according to claim 5.

7. In the first transport operation, the plurality of second contact portions are in contact with the wafer during a period from when the wafer passes through the inspection information acquisition unit until when the movement in one direction is stopped; In the second transport operation, the plurality of first contact portions are in contact with the wafer during a period from when the wafer passes through the inspection information acquisition unit until when the movement in the other direction is stopped; 7. The wafer inspection apparatus according to claim 6.

8. The abutment portion is a plurality of first contact portions that contact one outer peripheral edge of the wafer; a plurality of second contact portions disposed opposite the plurality of first contact portions across the wafer and contacting the other outer peripheral edge of the wafer; Equipped with The conveying unit is a conveying operation is performed in which the wafer is moved in one direction while being horizontally levitated by bringing the plurality of first contact portions into contact with one outer peripheral edge of the wafer and moving the plurality of first contact portions relative to the stage using the driving unit, and the wafer passes through the inspection information acquisition unit; when the movement of the wafer in the one direction by the transport operation is stopped, the plurality of second contact portions are in a state of contact with the wafer during a period from when the wafer passes through the inspection information acquisition unit until when the movement of the wafer in the one direction is stopped.

2. The wafer inspection apparatus according to claim 1.

9. a wafer conveyance device that passes a wafer through an inspection information acquiring unit that acquires inspection information in order to inspect the wafer for defects based on the inspection information obtained from the wafer, a stage on which the wafer is placed on a ventilation block, and which levitates the wafer horizontally above the ventilation block by discharging air from the ventilation block toward a surface of the wafer; a transport unit that transports the wafer horizontally levitated above the stage by air in one direction relative to the stage; Equipped with The conveying unit is a contact portion that contacts the outer periphery of the wafer that is horizontally levitated above the stage by air; a drive unit that moves the contact portion relative to the stage; the drive unit moves the contact unit relative to the stage to move the wafer in one direction, and the wafer passes through the inspection information acquisition unit while being horizontally levitated. Wafer transport device.

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