Foreign matter removal device and foreign matter removal method

Abstract

[Problem] To prevent a reduction in the yield of semiconductor device inspection and improve the throughput of semiconductor device inspection. [Solution] This foreign matter removal device comprises a plurality of roller pairs sandwiching a substrate therebetween. The plurality of roller pairs are arranged in a direction parallel to the surface of the substrate. The substrate reciprocates between the respective roller pairs in a parallel direction. The plurality of roller pairs have: a plurality of first roller pairs that come into contact with the substrate and drive the substrate in a forward direction; and a plurality of second roller pairs that come into contact with the substrate and drive the substrate in a backward direction. An adhesive sheet is interposed between the first roller pair and the substrate and / or between the second roller pair and the substrate.

Description

Foreign matter removal device and foreign matter removal method

[0001] The present disclosure relates to a foreign matter removal device and a foreign matter removal method.

[0002] In the manufacturing process of semiconductor devices, if foreign matter adheres to a wafer, it can adversely affect the film formation and etching processes performed on the wafer. Therefore, various processes are performed on the wafer in an atmosphere with extremely high levels of cleanliness, and various measures are taken to prevent foreign matter from adhering to the wafer.

[0003] On the other hand, in the inspection process for semiconductor devices formed on wafers, the wafers are not processed, so the cleanliness of the atmosphere is inferior to that of the manufacturing process, and measures to prevent foreign matter from adhering to the wafers after the semiconductor device manufacturing process are not actively taken. Furthermore, in the semiconductor device inspection process, each probe (needle) of the probe card is brought into contact with the electrode pads of the semiconductor device. However, since the surface of the electrode pads is covered with an oxide film or the like, contact with the probe peels off the oxide film, generating foreign matter. Therefore, it can be said that foreign matter is more likely to adhere to the wafers in the semiconductor device inspection process than in the semiconductor device manufacturing process.

[0004] In the semiconductor device testing process, a wafer is first attached to a mounting table, and then the wafer, along with the mounting table, is brought close to a probe card, bringing each probe of the probe card into contact with the electrode pads of the semiconductor device. Then, a current or voltage is applied from the probes to check the electrical characteristics of the semiconductor device. If foreign matter adheres to the backside of the wafer, the wafer partially lifts off the mounting table, preventing accurate contact of some electrode pads with the probes. Furthermore, if foreign matter adheres to the backside of the wafer, the wafer will not be uniformly attached to the mounting table, making it difficult to accurately control the temperature of the wafer mounting table and reproducing the test conditions. Therefore, a method for removing foreign matter from the backside of a wafer using an adhesive sheet has been proposed (see, for example, Patent Document 1).

[0005] Specifically, in the method described in Patent Document 1, when a wafer is placed in a housing having an opening at the top so as to close the opening, an adhesive sheet is interposed between the housing and the wafer, and the pressure inside the housing is reduced to draw the wafer toward the housing, thereby bringing the wafer into close contact with the adhesive sheet and transferring particles on the backside of the wafer to the adhesive sheet.

[0006] Japanese Patent Application Laid-Open No. 2007-157902

[0007] The technology according to the present disclosure prevents a decrease in the yield of semiconductor device inspection and improves the throughput of semiconductor device inspection.

[0008] One aspect of the technology disclosed herein is a foreign matter removal device comprising a plurality of roller pairs that sandwich a substrate therebetween, the plurality of roller pairs being arranged in a direction parallel to the surface of the substrate, the substrate moving back and forth in the parallel direction between each of the roller pairs, the plurality of roller pairs including a plurality of first roller pairs that contact the substrate and drive the substrate in a forward direction, and a plurality of second roller pairs that contact the substrate and drive the substrate in a return direction, and an adhesive sheet is interposed between the first roller pair and the substrate and at least one of the second roller pair and the substrate.

[0009] According to the technology of the present disclosure, it is possible to prevent a decrease in the yield of semiconductor device inspection and to improve the throughput of semiconductor device inspection.

[0010] FIG. 2 is a schematic diagram of the internal structure of a foreign matter removal device according to an embodiment of the technology disclosed herein, viewed from the side. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 4 is a diagram for explaining the internal structure of a first upper unit and a second upper unit in FIG. 1. FIG. 5 is a diagram for explaining the internal structure of the first upper unit and the second upper unit in FIG. 1. FIG. 6 is a process diagram for explaining a foreign matter removal method performed by the foreign matter removal device of FIG. 1. FIG. 7 is a process diagram for explaining a foreign matter removal method performed by the foreign matter removal device of FIG. 1. FIG. 8 is a process diagram for explaining a foreign matter removal method performed by the foreign matter removal device of FIG. 1. FIG. 9 is a process diagram for explaining a foreign matter removal method performed by the foreign matter removal device of FIG. 1. FIG. 10 is a schematic diagram of the internal structure of a modified foreign matter removal device, viewed from the side.

[0011] Incidentally, foreign particles can adhere not only to the back surface of a wafer but also to the front surface of the wafer. When foreign particles adhere to the front surface of the wafer, they become trapped between the probe and the electrode pad, resulting in poor electrical continuity and unstable measurements. Furthermore, when foreign particles adhere between adjacent electrode pads, they can short-circuit the electrode pads, destroying the semiconductor device or causing unstable measurements. As a result, semiconductor device inspection cannot be continued, resulting in a decrease in inspection yield. Furthermore, when semiconductor device inspection cannot be continued in this way, semiconductor device inspection must be stopped to investigate the cause and then cleaning must be performed, resulting in a decrease in throughput.

[0012] In contrast, the technology disclosed herein involves placing rollers in contact with the back and front surfaces of a wafer, and rotating each roller to move the wafer back and forth in a direction parallel to the plane of the wafer, with an adhesive sheet interposed between the wafer and each roller.

[0013] An embodiment of the technology according to the present disclosure will be described below with reference to the drawings. Fig. 1 is a schematic diagram of the internal structure of a foreign matter removal device according to an embodiment of the technology according to the present disclosure, viewed from the side. Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, which corresponds to a plan view of approximately the lower half of the internal structure of the foreign matter removal device of Fig. 1, viewed from above.

[0014] 1 and 2 is an apparatus for removing foreign matter, such as particles, adhering to the front and back surfaces of a circular silicon wafer W (substrate) on which a plurality of testable semiconductor devices are formed, while the wafer W is being transported in a horizontal direction. This foreign matter removal apparatus 10 removes foreign matter adhering to the front and back surfaces of the wafer W before or during the semiconductor device inspection process.

[0015] The particle removal apparatus 10 includes a plurality of, for example, six, drive modules 11, 12 arranged in a direction parallel to and substantially horizontal to the surface of the wafer W (hereinafter referred to as the "transfer direction"). These drive modules 11, 12 reciprocate the wafer W in the transfer direction and are divided into a first drive module 11 that drives the wafer W in a forward direction and a second drive module 12 that drives the wafer W in a backward direction. In this embodiment, the particle removal apparatus 10 includes three first drive modules 11 and three second drive modules 12. In the particle removal apparatus 10, the first drive modules 11 and the second drive modules 12 are alternately arranged along the transfer direction. Note that the number of first drive modules 11 and the number of second drive modules 12 are not limited to three; the particle removal apparatus 10 may include at least two first drive modules 11 and at least two second drive modules 12.

[0016] The first drive module 11 has a first upper unit 13 arranged above a movement path (hereinafter referred to as the "transfer path") for the reciprocating wafer W, and a first lower unit 14 arranged below the transfer path. The first upper unit 13 has a first upper drive roller 15 arranged below it and in contact with the wafer W moving along the transfer path. The first lower unit 14 has a first lower drive roller 16 arranged above it and in contact with the wafer W moving along the transfer path. In the first drive module 11, the first upper unit 13 and the first lower unit 14 face each other across the transfer path, and the first upper drive roller 15 and the first lower drive roller 16 form a first roller pair that sandwiches the wafer W therebetween.

[0017] The second drive module 12 has a second upper unit 17 arranged above the transfer path and a second lower unit 18 arranged below the transfer path. The second upper unit 17 has second upper drive rollers 19 arranged below it and in contact with the wafer W moving along the transfer path. The second lower unit 18 has second lower drive rollers 20 arranged above it and in contact with the wafer W moving along the transfer path. In the second drive module 12, the second upper unit 17 and the second lower unit 18 face each other across the transfer path, and the second upper drive rollers 19 and the second lower drive rollers 20 form a second roller pair that sandwich the wafer W therebetween.

[0018] The first upper drive roller 15 and the first lower drive roller 16 are configured to be rotatable about a central axis that extends parallel to the surface of the wafer W and is perpendicular to the transport direction. When the first upper drive roller 15 and the first lower drive roller 16 contact the wafer W, the first upper drive roller 15 rotates counterclockwise in FIG. 1 , and the first lower drive roller 16 rotates clockwise in FIG. 1 . As a result, the first upper drive roller 15 and the first lower drive roller 16 drive the wafer W to the right in FIG. 1 (the forward direction). At this time, the wafer W moves between the first upper drive roller 15 and the first lower drive roller 16 in each first drive module 11.

[0019] The second upper drive roller 19 and the second lower drive roller 20 are also configured to be rotatable about a central axis that extends parallel to the surface of the wafer W and is perpendicular to the transport direction. When the second upper drive roller 19 and the second lower drive roller 20 contact the wafer W, the second upper drive roller 19 rotates clockwise in FIG. 1 , and the second lower drive roller 20 rotates counterclockwise in FIG. 1 . As a result, the second upper drive roller 19 and the second lower drive roller 20 drive the wafer W to the left in FIG. 1 (the return direction). At this time, the wafer W moves between the second upper drive roller 19 and the second lower drive roller 20 in each second drive module 12.

[0020] In the first drive module 11, the first upper unit 13 and the first lower unit 14 are configured to be movable up and down by actuators (not shown). The actuators adjust the contact forces between the first upper drive rollers 15 and the first lower drive rollers 16 and the wafer W by moving the first upper unit 13 and the first lower unit 14 up and down. Furthermore, in the second drive module 12, the second upper unit 17 and the second lower unit 18 are also configured to be movable up and down by actuators (not shown). The contact forces between the second upper drive rollers 19 and the second lower drive rollers 20 and the wafer W are also adjusted by the actuators.

[0021] When the first roller pair (first upper drive roller 15, first lower drive roller 16) of each first drive module 11 drives the wafer W in the forward direction, the second upper unit 17 moves upward and the second lower unit 18 moves downward. As a result, the second upper drive roller 19 and the second lower drive roller 20 are spaced apart from the transport path, preventing the first roller pair from interfering with the driving of the wafer W in the forward direction.

[0022] Furthermore, when the second roller pair (second upper drive roller 19, second lower drive roller 20) of each second drive module 12 drives the wafer W in the return direction, the first upper unit 13 moves upward and the first lower unit 14 moves downward. As a result, the first upper drive roller 15 and the first lower drive roller 16 are spaced apart from the transport path, preventing the second roller pair from interfering with the driving of the wafer W in the forward direction.

[0023] In the first upper unit 13, an adhesive sheet 21 is wound around the first upper drive roller 15, the adhesive sheet 21 is interposed between the first upper drive roller 15 and the wafer W, and the adhesive sheet 21 is pressed by the first upper drive roller 15 to come into contact with the wafer W. In the first lower unit 14, an adhesive sheet 22 is wound around the first lower drive roller 16, the adhesive sheet 22 is interposed between the first lower drive roller 16 and the wafer W, and the adhesive sheet 22 is pressed by the first lower drive roller 16 to come into contact with the wafer W.

[0024] In the second upper unit 17, an adhesive sheet 23 is wound around the second upper drive roller 19, and the adhesive sheet 23 is interposed between the second upper drive roller 19 and the wafer W, and the adhesive sheet 23 is pressed by the second upper drive roller 19 to come into contact with the wafer W. In the second lower unit 18, an adhesive sheet 24 is wound around the second lower drive roller 20, and the adhesive sheet 24 is interposed between the second lower drive roller 20 and the wafer W, and the adhesive sheet 24 is pressed by the second lower drive roller 20 to come into contact with the wafer W.

[0025] In addition to the first upper drive roller 15, the first upper unit 13 has a first upper feed roller 25 and a first upper take-up roller 26. The first upper feed roller 25 and the first upper take-up roller 26 are disposed above the first upper drive roller 15 such that their central axes are parallel to the central axis of the first upper drive roller 15 (see FIG. 3A). In addition, the adhesive sheet 21 is also wound around each of the first upper feed roller 25 and the first upper take-up roller 26.

[0026] In the first upper unit 13, the adhesive sheet 21 moves in the rotation direction of the first upper drive roller 15 due to the rotational drive of the first upper drive roller 15 (see the black arrow in FIG. 3A ). The first upper feed roller 25 is disposed upstream of the first upper drive roller 15 in the movement direction of the adhesive sheet 21, and the first upper take-up roller 26 is disposed downstream of the first upper drive roller 15 in the movement direction of the adhesive sheet 21. As the adhesive sheet 21 moves, the first upper feed roller 25 feeds the adhesive sheet 21 toward the first upper drive roller 15 (see the downward white arrow in FIG. 3A ). Furthermore, as the adhesive sheet 21 moves, the first upper take-up roller 26 takes up the adhesive sheet 21 fed from the first upper drive roller 15 (see the upward white arrow in FIG. 3A ).

[0027] That is, in the first upper unit 13, when the wafer W is driven in the forward direction by the rotation of the first upper drive roller 15, the adhesive sheet 21 in contact with the wafer W moves in the rotation direction of the first upper drive roller 15. As a result, the surface of the wafer W is essentially scanned by the adhesive sheet 21, and foreign matter adhering to the surface of the wafer W is transferred to and removed by the adhesive sheet 21. Furthermore, when the surface of the wafer W is scanned by the adhesive sheet 21, a portion of the adhesive sheet 21 that has once come into contact with the wafer W is prevented from contacting the wafer W again, so that foreign matter transferred to the adhesive sheet 21 can be prevented from being transferred again to the surface of the wafer W.

[0028] In addition to the first lower drive roller 16, the first lower unit 14 also has a first lower feed roller 27 and a first lower take-up roller 28. The first lower feed roller 27 and the first lower take-up roller 28 are disposed below the first lower drive roller 16 such that their central axes are parallel to the central axis of the first lower drive roller 16. In addition, the adhesive sheet 22 is also wound around each of the first lower feed roller 27 and the first lower take-up roller 28.

[0029] In the first lower unit 14, the adhesive sheet 22 moves in the rotation direction of the first lower drive roller 16 due to the rotational drive of the first lower drive roller 16. The first lower feed roller 27 is disposed upstream of the first lower drive roller 16 in the movement direction of the adhesive sheet 22, and the first lower winding roller 28 is disposed downstream of the first lower drive roller 16 in the movement direction of the adhesive sheet 22. As the adhesive sheet 22 moves, the first lower feed roller 27 feeds the adhesive sheet 22 toward the first lower drive roller 16, and the first lower winding roller 28 winds up the adhesive sheet 22 fed from the first lower drive roller 16.

[0030] That is, in the first lower unit 14, when the wafer W is driven in the forward direction by the rotation of the first lower drive roller 16, the adhesive sheet 22 in contact with the wafer W moves in the rotation direction of the first lower drive roller 16. As a result, the back surface of the wafer W is essentially scanned by the adhesive sheet 22, and foreign matter adhering to the back surface of the wafer W is transferred to and removed by the adhesive sheet 22. Furthermore, when the back surface of the wafer W is scanned by the adhesive sheet 22, a portion of the adhesive sheet 22 that has once come into contact with the wafer W is prevented from coming into contact with the wafer W again, so that foreign matter transferred to the adhesive sheet 22 can be prevented from being transferred again to the front surface of the wafer W.

[0031] In addition to the second upper drive roller 19, the second upper unit 17 also has a second upper feed roller 29 and a second upper take-up roller 30. The second upper feed roller 29 and the second upper take-up roller 30 are disposed above the second upper drive roller 19 such that their central axes are parallel to the central axis of the second upper drive roller 19 (see FIG. 3B ). In addition, the adhesive sheet 23 is also wound around each of the second upper feed roller 29 and the second upper take-up roller 30.

[0032] In the second upper unit 17, the adhesive sheet 23 moves in the rotation direction of the second upper drive roller 19 due to the rotational drive of the second upper drive roller 19 (see the black arrow in FIG. 3B ). The second upper feed roller 29 is disposed upstream of the second upper drive roller 19 in the movement direction of the adhesive sheet 23, and the second upper take-up roller 30 is disposed downstream of the second upper drive roller 19 in the movement direction of the adhesive sheet 23. As the adhesive sheet 23 moves, the second upper feed roller 29 feeds the adhesive sheet 23 toward the second upper drive roller 19 (see the downward white arrow in FIG. 3B ). Furthermore, as the adhesive sheet 23 moves, the second upper take-up roller 30 takes up the adhesive sheet 23 fed from the second upper drive roller 19 (see the upward white arrow in FIG. 3B ).

[0033] That is, in the second upper unit 17, when the wafer W is driven in the return direction by the rotation of the second upper drive roller 19, the adhesive sheet 23 in contact with the wafer W moves in the rotation direction of the second upper drive roller 19. As a result, the surface of the wafer W is essentially scanned by the adhesive sheet 23, and foreign matter adhering to the surface of the wafer W is transferred to and removed from the adhesive sheet 23. Furthermore, when the surface of the wafer W is scanned by the adhesive sheet 23, a portion of the adhesive sheet 23 that has once come into contact with the wafer W is prevented from coming into contact with the wafer W again, so that foreign matter transferred to the adhesive sheet 23 can be prevented from being transferred again to the surface of the wafer W.

[0034] The second lower unit 18 has, in addition to the second lower drive roller 20, a second lower feed roller 31 and a second lower take-up roller 32. The second lower feed roller 31 and the second lower take-up roller 32 are disposed below the second lower drive roller 20 such that their central axes are parallel to the central axis of the second lower drive roller 20. In addition, the adhesive sheet 24 is also wound around each of the second lower feed roller 31 and the second lower take-up roller 32.

[0035] In the second lower unit 18, the adhesive sheet 24 moves in the rotation direction of the second lower drive roller 20 due to the rotational drive of the second lower drive roller 20. The second lower feed roller 31 is disposed upstream of the second lower drive roller 20 in the movement direction of the adhesive sheet 24, and the second lower winding roller 32 is disposed downstream of the second lower drive roller 20 in the movement direction of the adhesive sheet 24. As the adhesive sheet 24 moves, the second lower feed roller 31 feeds the adhesive sheet 24 toward the second lower drive roller 20, and the second lower winding roller 32 winds up the adhesive sheet 24 fed from the second lower drive roller 20.

[0036] That is, in the second lower unit 18, when the wafer W is driven in the return direction by the rotation of the second lower drive roller 20, the adhesive sheet 24 in contact with the wafer W moves in the rotation direction of the second lower drive roller 20. As a result, the back surface of the wafer W is essentially scanned by the adhesive sheet 24, and foreign matter adhering to the back surface of the wafer W is transferred to and removed by the adhesive sheet 24. Furthermore, when the back surface of the wafer W is scanned by the adhesive sheet 24, a portion of the adhesive sheet 24 that has once come into contact with the wafer W is prevented from coming into contact with the wafer W again, so that foreign matter transferred to the adhesive sheet 24 can be prevented from being transferred again to the front surface of the wafer W.

[0037] Furthermore, each of the first upper units 13, each of the first lower units 14, each of the second upper units 17, and each of the second lower units 18 is configured to be individually replaceable. For example, the time to replace the first upper unit 13 is determined based on the amount of adhesive sheet 21 fed from the first upper feed roller 25 and the thickness of the adhesive sheet 21 taken up by the first upper take-up roller 26. Specifically, it is determined that the first upper unit 13 should be replaced when the amount of adhesive sheet 21 fed from the first upper feed roller 25 reaches the length of the adhesive sheet 21 originally wound around the first upper feed roller 25. Alternatively, it is determined that the first upper unit 13 should be replaced when the thickness of the adhesive sheet 21 taken up by the first upper take-up roller 26 reaches a thickness equivalent to the length of the adhesive sheet 21 originally wound around the first upper feed roller 25. The replacement times for the first lower unit 14, the second upper unit 17 and the second lower unit 18 are also determined based on the amount of adhesive sheets 22, 23 and 24 dispensed and the thickness of the wound adhesive sheets 22, 23 and 24.

[0038] In the foreign matter removal apparatus 10, as described above, when the wafer W moves back and forth along the transfer path, the front surface of the wafer W is scanned by the adhesive sheets 21 and 23, and the back surface of the wafer W is scanned by the adhesive sheets 22 and 24, thereby removing foreign matter. Therefore, the amount of movement of the wafer W in the transfer direction needs to be set so that no part of the front surface of the wafer W does not come into contact with the adhesive sheets 21 and 23. Furthermore, the amount of movement of the wafer W in the transfer direction needs to be set so that no part of the back surface of the wafer W does not come into contact with the adhesive sheets 22 and 24. In the foreign matter removal apparatus 10, the wafer W first moves in the forward direction and then moves in the backward direction. Therefore, in this embodiment, when the wafer W moves in the forward direction, the amount of movement of the wafer W is set so that the rear end of the wafer W in the forward direction reaches at least the first drive module 11, which is disposed furthest rearward in the forward direction. In FIG. 2, when the wafer W moves in the forward direction, the movement amount of the wafer W is set so that the left end of the wafer W comes into contact with the first lower drive roller 16 of the first drive module 11 arranged at the far left.

[0039] The foreign substance removal apparatus 10 also includes an outgoing path stopper 33 and a returning path stopper 34 disposed on the transfer path. The outgoing path stopper 33 is disposed further forward in the forward direction than the first drive module 11, which is disposed furthest forward in the forward direction on the transfer path. Referring to FIG. 2 , the outgoing path stopper 33 is disposed to the right of the first lower drive roller 16 of the rightmost first drive module 11. Furthermore, the returning path stopper 34 is disposed further forward in the return direction than the second drive module 12, which is disposed furthest forward in the return direction on the transfer path. Referring to FIG. 2 , the returning path stopper 34 is disposed to the right of the second lower drive roller 20 of the leftmost second drive module 12. This prevents the wafer W moving along the transfer path from jumping out and falling out of the foreign substance removal apparatus 10. However, in the foreign substance removal apparatus 10, the reciprocating movement of the wafer W is controlled by each of the first drive modules 11 and each of the second drive modules 12. This allows each first drive module 11 and each second drive module 12 to stop the wafer W at the limit movement position in the forward or backward direction. Therefore, the provision of the forward path stopper 33 and the backward path stopper 34 is not essential, and the forward path stopper 33 and the backward path stopper 34 may be omitted from the foreign matter removal apparatus 10.

[0040] In the following description of this embodiment, the first drive module 11 arranged at the rearmost position in the forward direction will be referred to as the "rearmost first drive module 11." Also, the second drive module 12 arranged at the frontmost position in the backward direction will be referred to as the "foremost second drive module 12."

[0041] Furthermore, in the foreign matter removal apparatus 10, the rearmost first drive module 11 and the frontmost second drive module 12 are disposed at a distance from each other in the transfer direction so as to form an entry space S between them, through which a pick 35 (part of the transfer mechanism) of the transfer arm can enter. In terms of Fig. 2, the frontmost second drive module 12 and the rearmost first drive module 11 are disposed at a distance L between them so that the distance L is greater than the width of the pick 35 of the transfer arm. Note that the distance L is set to be smaller than the diameter of the wafer W.

[0042] A green light 36 and a camera 37 are disposed above the transfer path in the entry space S, and an ionizer 38 (static eliminator) is also disposed therein. The green light 36, camera 37, and ionizer 38 are disposed so as to face the surface of the wafer W transferred into the entry space S by the transfer arm pick 35. The green light 36 irradiates the surface of the wafer W with green light to highlight the presence of minute foreign particles. The camera 37 photographs the surface of the wafer W illuminated with the green light. Therefore, the green light 36 and the camera 37 constitute an observation mechanism. The image captured by the camera 37 is transmitted to the control unit of the foreign particle removal apparatus 10 or an external control device, and it is determined based on the image whether or not foreign particles to be removed are present on the surface of the wafer W. The ionizer 38 also emits ions onto the surface of the wafer W to neutralize the surface of the wafer W and prevent foreign particles from re-adhering to the surface of the wafer W due to electrostatic force.

[0043] In addition, a green light 39 and a camera 40 are disposed below the transfer path in the entry space S, and an ionizer 41 is also disposed therein. The green light 39, the camera 40, and the ionizer 41 are disposed so as to face the back surface of the wafer W transferred into the entry space S by the transfer arm pick 35. The green light 39 irradiates the back surface of the wafer W with green light to highlight the presence of minute foreign matter. The camera 40 photographs the back surface of the wafer W irradiated with the green light. Therefore, the green light 39 and the camera 40 also constitute an observation mechanism. The image captured by the camera 40 is transmitted to the control unit of the foreign matter removal apparatus 10 or an external control device, and it is determined based on the image whether or not foreign matter to be removed is present on the back surface of the wafer W. The ionizer 41 also emits ions to the back surface of the wafer W to neutralize the back surface of the wafer W and prevent foreign matter from re-adhering to the back surface of the wafer W due to electrostatic force.

[0044] In the foreign matter removal apparatus 10, laser scanners may be provided instead of the green lights 36, 39 and the cameras 37, 40. In this case, the laser scanner scans the front and back surfaces of the wafer W, and the presence or absence of foreign matter to be removed is determined based on the scanning results. Furthermore, if foreign matter adhering to the front and back surfaces of the wafer W is always removed when the wafer W is carried into the foreign matter removal apparatus 10, the green lights 36, 39, the cameras 37, 40, and the ionizers 38, 41 do not need to be provided in the entry space S.

[0045] 4A to 4C and 5A to 5C are process diagrams illustrating the foreign matter removal method performed by the foreign matter removal device 10. 4A to 4C and 5A to 5C show the internal structure of the foreign matter removal device 10 as viewed from the side. Note that in 4A to 4C and 5A to 5C, the outgoing path stopper 33, the returning path stopper 34, the green lights 36 and 39, the cameras 37 and 40, and the ionizers 38 and 41 are not shown.

[0046] First, the pick 35 of the transfer arm supporting the wafer W enters the entry space S. At this time, the first upper units 13 and the second upper units 17 move upward to positions (non-contact positions) where they do not come into contact with the wafer W moving along the transfer path. Furthermore, the first lower units 14 and the second lower units 18 move downward to positions (non-contact positions) where they do not come into contact with the wafer W moving along the transfer path ( FIG. 4A ). This prevents the wafer W from interfering with the first upper unit 13, the first lower unit 14, the second upper unit 17, or the second lower unit 18 when the pick 35 enters the entry space S.

[0047] Next, the front and rear surfaces of the wafer W are photographed by the green lights 36, 39 and the cameras 37, 40, and it is determined whether or not there is any foreign matter to be removed on the front or rear surface of the wafer W. If there is no foreign matter to be removed on the front or rear surface of the wafer W, the foreign matter removal method described below is omitted, and the pick 35 of the transfer arm supporting the wafer W exits the entry space S as is.

[0048] On the other hand, if foreign matter to be removed is present on the front or back surface of the wafer W, the ionizers 38, 41 first neutralize the front or back surface of the wafer W. Then, each first upper unit 13 moves downward to a position where its first upper drive roller 15 contacts the wafer W moving along the transfer path. Furthermore, each first lower unit 14 moves upward to a position where its first lower drive roller 16 contacts the wafer W moving along the transfer path. At this time, the wafer W is clamped between the first upper unit 13 and the first lower unit 14 of the rearmost first drive module 11. Furthermore, the pick 35 of the transfer arm retracts from the entry space S ( FIG. 4B ).

[0049] Next, the first upper drive rollers 15 of each first upper unit 13 rotate, and the first lower drive rollers 16 of each first lower unit 14 rotate to drive the wafer W in the forward direction ( FIG. 4C ). At this time, the adhesive sheet 21 in each first upper unit 13 is pressed by the first upper drive rollers 15 and comes into contact with the wafer W, and the adhesive sheet 22 in each first lower unit 14 is pressed by the first lower drive rollers 16 and comes into contact with the wafer W. As a result, foreign matter adhering to the front surface of the wafer W is transferred to and removed from each adhesive sheet 21, and further, foreign matter adhering to the back surface of the wafer W is transferred to and removed from the adhesive sheet 22.

[0050] Thereafter, when the rear end of the wafer W in the forward direction comes into contact with the first upper drive rollers 15 or the first lower drive rollers 16 of the rearmost first drive module 11, the first upper drive rollers 15 and the first lower drive rollers 16 stop rotating, thereby stopping the movement of the wafer W in the forward direction.

[0051] Next, each first upper unit 13 moves upward to a position where it does not contact the wafer W moving along the transfer path. Furthermore, each second lower unit 18 moves upward to a position where its second lower drive rollers 20 contact the wafer W moving along the transfer path, and the wafer W is supported by each second lower drive roller 20. Thereafter, each first lower unit 14 moves downward to a position where it does not contact the wafer W moving along the transfer path, and each second upper unit 17 moves downward to a position where its second upper drive rollers 19 contact the wafer W moving along the transfer path. As a result, the wafer W is sandwiched between each second upper unit 17 and each second lower unit 18 ( FIG. 5A ). Alternatively, each second upper unit 17 may move downward before each first lower unit 14 moves downward.

[0052] Next, the second upper drive rollers 19 of each second upper unit 17 rotate, and the second lower drive rollers 20 of each second lower unit 18 rotate to drive the wafer W in the return direction ( FIG. 5B ). At this time, the adhesive sheet 23 in each second upper unit 17 is pressed by the second upper drive rollers 19 into contact with the wafer W, and the adhesive sheet 24 in each second lower unit 18 is pressed by the second lower drive rollers 20 into contact with the wafer W. As a result, foreign matter adhering to the front surface of the wafer W that was not completely removed by each adhesive sheet 21 is transferred to and removed by each adhesive sheet 23. Furthermore, foreign matter adhering to the back surface of the wafer W that was not completely removed by each adhesive sheet 22 is transferred to and removed by the adhesive sheet 24.

[0053] Thereafter, when the wafer W comes into contact with the second upper drive rollers 19 and the second lower drive rollers 20 of the second drive module 12 at the forefront and further moves a predetermined distance in the return direction, the second upper drive rollers 19 and the second lower drive rollers 20 stop rotating, thereby stopping the return movement of the wafer W.

[0054] Next, the front and rear surfaces of the wafer W are photographed by the green lights 36, 39 and the cameras 37, 40, and it is determined whether or not any foreign matter to be removed remains on the front and rear surfaces of the wafer W. If any foreign matter to be removed remains on the front and rear surfaces of the wafer W, the steps of Figures 4B to 5B are executed again, and the foreign matter remaining on the front and rear surfaces of the wafer W is removed by the adhesive sheets 21 to 24 when the wafer W is moved back and forth along the transfer path. The steps of Figures 4B to 5B are repeatedly executed until it is determined that no foreign matter to be removed remains on the front and rear surfaces of the wafer W.

[0055] On the other hand, if no foreign matter to be removed remains on the front or back surface of the wafer W, the picks 35 of the transfer arm enter the access space S and support the wafer W. Thereafter, each second upper unit 17 moves upward to a position where it does not come into contact with the wafer W supported by the picks 35. Also, each second lower unit 18 moves downward to a position where it does not come into contact with the wafer W supported by the picks 35 (FIG. 5C). As a result, the wafer W is supported only by the picks 35, and the transfer arm can remove the wafer W from the access space S.

[0056] According to the foreign matter removal apparatus 10, when the wafer W is moved back and forth along the transfer path, not only is the backside of the wafer W substantially scanned by the adhesive sheets 22 and 24, but the front side of the wafer W is also substantially scanned by the adhesive sheets 21 and 23. This removes foreign matter adhering not only to the backside of the wafer W but also to the front side of the wafer W, preventing foreign matter from becoming trapped between the probes of the probe card and the electrode pads of the semiconductor device and preventing foreign matter from adhering between adjacent electrode pads. This prevents poor electrical continuity to the electrode pads and short-circuiting between the electrode pads during the semiconductor device testing process, thereby avoiding damage to the semiconductor device and the interruption of the semiconductor device testing. As a result, a decrease in the yield of semiconductor device testing is prevented and the throughput of semiconductor device testing is improved.

[0057] Furthermore, in the foreign matter removal apparatus 10, foreign matter is removed by moving the wafer W back and forth along the transfer path, so the area over which the wafer W moves when removing foreign matter can be reduced. Furthermore, because the wafer W can be loaded and unloaded into and from the foreign matter removal apparatus 10 using the same entrance space S, there is no need to provide an unloading outlet for the wafer W separately from the loading inlet for the wafer W. As a result, the foreign matter removal apparatus 10 can be prevented from becoming large.

[0058] Furthermore, in the foreign matter removal apparatus 10, each of the first drive modules 11 and the second drive modules 12 transports the wafer W only in either the forward direction or the backward direction. This eliminates the need to provide a mechanism for transporting the wafer W in both the forward direction and the backward direction in the first drive module 11 and the second drive module 12, thereby simplifying the configuration of the first drive module 11 and the second drive module 12.

[0059] Furthermore, since the foreign matter removal device 10 does not require decompression as in the method described in Patent Document 1, the configuration of the foreign matter removal device 10 can be relatively simplified.

[0060] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist of the present disclosure.

[0061] For example, in the foreign matter removal apparatus 10, foreign matter adhering to the front and back surfaces of the wafer W is removed by the adhesive sheets 23, 24 when the wafer W moves not only in the forward direction but also in the return direction. However, the foreign matter removal apparatus may be configured to remove foreign matter adhering to the front and back surfaces of the wafer W only when the wafer W moves in the forward direction or only when the wafer W moves in the return direction. For example, a foreign matter removal apparatus 42 that removes foreign matter only when the wafer W moves in the forward direction has the same configuration as the foreign matter removal apparatus 10, but instead of the three second drive modules 12, it has three drive roller pairs 43 that drive the wafer W in the return direction ( FIG. 6 ). Each drive roller of the drive roller pair 43 is configured to be movable in the vertical direction and moves away from the transfer path when the wafer W moves in the forward direction. Furthermore, when the wafer W moves in the return direction, it moves to a position where it contacts the wafer W and drives the wafer W in the return direction.

[0062] The foreign matter removal apparatus 10 may be configured as an independent apparatus or as a part of another apparatus, for example, a prober, which is an inspection apparatus. Furthermore, the foreign matter removal apparatus 10 may be configured to remove foreign matter adhering not only to the wafer W but also to the front and back surfaces of other substrates, for example, glass substrates.

[0063] This application claims priority based on Japanese Patent Application No. 2024-107274, filed on July 3, 2024, the entire contents of which are incorporated herein by reference.

[0064] S: Entry space W: Wafer 10: Foreign matter removal device 11: First driving module 12: Second driving module 15: First upper driving roller 16: First lower driving roller 19: Second upper driving roller 20: Second lower driving roller 21, 22, 23, 24: Adhesive sheet 36, 39: Green light 37, 40: Camera 38, 41: Ionizer

Claims

1. A foreign matter removal device comprising a plurality of roller pairs that sandwich a substrate therebetween, the plurality of roller pairs being arranged in a direction parallel to the surface of the substrate, the substrate moving back and forth between each of the roller pairs in the parallel direction, the plurality of roller pairs having a plurality of first roller pairs that contact the substrate and drive the substrate in a forward direction, and a plurality of second roller pairs that contact the substrate and drive the substrate in a return direction, and an adhesive sheet being interposed between the first roller pair and the substrate, and at least one of the pairs of rollers and the second roller pair and the substrate.

2. The foreign matter removal device of claim 1, wherein when the first pair of rollers drives the substrate, the second pair of rollers moves away from the substrate, and when the second pair of rollers drives the substrate, the first pair of rollers moves away from the substrate.

3. The foreign matter removal device according to claim 1, wherein the first roller pair and the second roller pair are arranged alternately along the parallel direction.

4. The foreign matter removal device according to claim 1, wherein the adhesive sheet is interposed between the first roller pair and the substrate and between the second roller pair and the substrate.

5. A foreign matter removal device as described in claim 4, wherein when the adhesive sheet is wound around the first pair of rollers and the first pair of rollers comes into contact with the substrate, the adhesive sheet moves in the rotational direction of the first pair of rollers as the first pair of rollers is rotated, and when the adhesive sheet is wound around the second pair of rollers and the second pair of rollers comes into contact with the substrate, the adhesive sheet moves in the rotational direction of the second pair of rollers as the second pair of rollers is rotated.

6. A foreign matter removal device as described in claim 1, wherein one of the plurality of first roller pairs and a second roller pair adjacent to the first roller pair are arranged spaced apart from each other in the parallel direction so as to form an entry space between them through which a part of the substrate transport mechanism can enter.

7. The foreign matter removal device according to claim 6, further comprising an observation mechanism disposed in the entry space for observing at least one of the front and back surfaces of the substrate.

8. The foreign matter removal device according to claim 7, wherein the observation mechanism includes a green light and a camera.

9. The foreign matter removal device according to claim 6, further comprising a static eliminator disposed in the entrance space for eliminating static electricity from at least one of the front and back surfaces of the substrate.

10. The foreign matter removal apparatus according to claim 1, wherein a plurality of inspectable semiconductor devices are formed on the surface of said substrate.

11. The foreign matter removal device according to claim 10, wherein the substrate is a circular wafer made of silicon.

12. A method for removing foreign matter, comprising: sandwiching the substrate between a plurality of roller pairs arranged in a direction parallel to the surface of the substrate; and driving the substrate by the plurality of roller pairs to move the substrate back and forth in the parallel direction; wherein the plurality of roller pairs have a plurality of first roller pairs that contact the substrate and drive the substrate in a forward direction, and a plurality of second roller pairs that contact the substrate and drive the substrate in a return direction; and wherein an adhesive sheet is interposed between the first roller pair and the substrate, and at least one of the pairs of rollers and the second roller pair and the substrate.

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