Wafer peeling and cleaning apparatus

Abstract

To provide a wafer peeling and cleaning apparatus that can reduce a frequency of occurrence of defects such as chipping, enhance a processing capacity, or enhance a quality of a wafer which has been made into a sheet.SOLUTION: In a wafer peeling and cleaning apparatus that peels and makes wafers which have been cut out from an ingot and formed into a batch state, into a sheet one by one from a slice base, and cleans the peeled wafer one by one, the apparatus includes: a peeling unit including an arm which holds and peels the wafer from the slice base; and a load detection unit which detects a load of the arm. The load detection unit detects the load at least when the wafer is peeled off from the slice base.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a wafer peeling and cleaning apparatus, and more particularly to a wafer peeling and cleaning apparatus that peels wafers that have been simultaneously cut into a large number (plurality) of pieces by a wire saw and put into a batch state (bundled state) from a slice base to separate them into individual pieces and clean them. [Background technology]

[0002] When an ingot is cut with a wire saw, the wafers are cut out while still attached to the slice base. Therefore, the wafers are peeled off from the slice base and separated into individual wafers. A wafer peeling and cleaning device disclosed in Patent Document 1 is known as a device for performing this process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-120094 A Summary of the Invention [Problem to be solved by the invention]

[0004] The wafer peeling and cleaning apparatus described in Patent Document 1 had excellent performance and was original. However, the quality required for the single wafer and the processing capacity required for the apparatus are constantly increasing. In view of the current demands, the conventional wafer peeling and cleaning apparatus has room for improvement in terms of the frequency of defects such as chipping, processing capacity, and the quality of the single wafer.

[0005] The wafer peeling and cleaning apparatus disclosed in this specification can reduce the frequency of occurrence of defects such as chipping, improve processing capacity, or improve the quality of single-wafer wafers. [Means for solving the problem]

[0006] The first wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus that peels wafers cut from an ingot into a batch state one by one from a slice base to separate them into individual wafers and cleans the peeled wafers individually, and is equipped with a peeling unit including an arm that holds the wafer and peels it from the slice base, and a load detection unit that detects the load of the arm, and the load detection unit detects at least the load when the wafer is peeled from the slice base. Effect of the Invention

[0007] The wafer peeling and cleaning apparatus disclosed in this specification can reduce the frequency of occurrence of defects such as chipping, improve processing capacity, or improve the quality of single-wafer wafers. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an overall plan view of the wafer separating and cleaning apparatus. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a front view of the peeling device and the hot water tank. [Figure 4] FIG. [Diagram 5] FIG. 2 is an enlarged side view of a main part of the peeling unit. [Figure 6] FIG. 2 is an enlarged front view of a main part of the peeling unit. [Figure 7] FIG. [Figure 8] FIG. 11 is an explanatory diagram showing the action of air during peeling. [Figure 9] 1 is a schematic diagram of an image captured above a wafer W by a camera. [Figure 10] 11 is an explanatory diagram of the operation of the one-piece adjustment unit. FIG. [Figure 11] FIG. 4 is a plan view showing the shape of a nozzle hole. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The first wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus that peels wafers cut from an ingot into a batch state one by one from a slice base to separate them into individual wafers and cleans the peeled wafers individually, and is equipped with a peeling unit including an arm that holds the wafer and peels it from the slice base, and a load detection unit that detects the load of the arm, and the load detection unit detects at least the load when the wafer is peeled from the slice base.

[0010] The first wafer peeling and cleaning device includes a load detector for detecting the load of the arm and is configured to detect the load when the wafer is peeled off from the slice base, so that an abnormality during peeling can be accurately detected. Before the peeling, the wafer is preferably supported so as to be attached to the slice base and to stand on its own, and when the peeling operation starts, the wafer is preferably easily separated from the slice base by the stress from the arm. Such a preferable situation is realized by adjusting the adhesive force between the slice base and the wafer. In other words, if the adhesive force is not appropriately adjusted, specifically, if the adhesive force is weak, the wafer will float up from the slice base before the peeling operation, tilt, and change its posture from the intended state, and will be damaged during peeling. Conversely, if the adhesive force is strong, the wafer will not be easily peeled off, and the peeling operation will need to be repeated, or the wafer will be damaged during peeling.

[0011] The first wafer peeling and cleaning equipment can indirectly monitor this adhesive force by detecting the load on the arm during peeling. If the load is abnormal (too small or too large), it can be confirmed that the wafer may have defects such as scratches or chips. Because the first wafer peeling and cleaning equipment can detect the load on the arm during peeling, this data can be used to distinguish wafers that may have defects (that have inherent defects) and to use it as an index for the operation of the equipment. As a result, defects are less likely to occur, the quality of the single wafers is improved, and processing capacity is improved.

[0012] The second wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus which, in the first wafer peeling and cleaning apparatus, is provided with a single-piece adjustment unit including a slit whose width is adjusted to allow the wafers transferred by the peeling unit to pass through one by one after being peeled, and the load detection unit detects the load when the wafer peeled off from the slice base is transferred while held by the arm and passes through the slit.

[0013] The second wafer peeling and cleaning equipment is equipped with a single-piece pick-up adjustment unit, so it can more reliably pick up "one" wafer. Furthermore, the load detection unit detects the load when the wafer peeled from the slice base passes through the slit of the single-piece pick-up adjustment unit, so it can detect the possibility of defects at this stage.

[0014] When passing through the slit, if a load different from the normal load, for example a larger load, is detected, there is a high possibility that a defect has occurred. For example, when a peeled wafer is transported, the next wafer (second wafer) waiting to be peeled may come into contact with a part of the wafer, and the surfaces may adhere to each other via water or the like, and the second wafer may be pulled and transported together (linking). When linking occurs, a load larger than normal occurs when passing through the slit. In many cases, even if linking occurs, the wafer can pass through the slit, but the wafer (first wafer, second wafer) that caused linking often has some kind of defect (scratch, chip). The second wafer peeling and cleaning device can monitor the load when passing through the slit, and therefore can detect the possibility of the occurrence of defects that may occur when passing through the slit, including linking. As a result, defects are less likely to occur and the quality of the wafers that are separated into single wafers is improved.

[0015] The third wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus in which, in the second wafer peeling and cleaning apparatus, the peeling unit is configured to transport the wafer held by the arm at a predetermined speed, and the load detection unit determines whether the detected load is from the peeling or from passing through the slit, based on the current position of the wafer calculated based on the time from the start of the peeling by the peeling unit.

[0016] The third wafer peeling and cleaning equipment can distinguish whether the load detected over time by the load detection unit is from peeling or from passing through a slit. If the stress history of a single wafer from peeling to passing through a slit can be understood from the load information, and peeling and passing through a slit can be distinguished, the magnitude of the load becomes basic information for judging the possibility of defects occurring at each stage. This determination is made based on the current wafer position, which is calculated based on the time from the start of peeling. By keeping constant the time and number of oscillations during peeling, and the wafer movement speed, the current wafer position is determined based on the time from the start of peeling. By adding the initial wafer position, which is a fixed position, and the position of the slit plate, to this, each detected peak can be attributed to peeling or slit passage from the load value data of the force versus time.

[0017] The fourth wafer peeling and cleaning apparatus is a wafer peeling and cleaning apparatus which is a first to third wafer peeling and cleaning apparatus, and which includes a hot water tank configured to store hot water, immerse at least the slice base in the hot water, and adjust the adhesive strength of the adhesive bonding the wafer and the slice base, and a temperature control unit which adjusts the temperature of the hot water, and the temperature control unit adjusts the temperature of the hot water based on the magnitude of the load during peeling.

[0018] If the load during peeling is greater than the expected value, it is assumed that the adhesive force between the wafer and the slice base is too strong. If the adhesive force is too strong, the peeling operation may take a long time, the peeling operation may have to be repeated, or even peeling may not be completed and an operator may have to deal with the problem, resulting in a decrease in processing capacity. In this case, the temperature control unit adjusts the temperature of the hot water so as to reduce the adhesive force. Whether the temperature of the hot water is increased or decreased is determined according to the properties of the adhesive. For example, if the load is too large, the temperature of the hot water is increased to soften the adhesive further.

[0019] On the other hand, if the load during peeling is smaller than the expected value, it is assumed that the adhesive strength between the wafer and the slice base is too weak. If the adhesive strength is too weak, the first and / or second and subsequent wafers may not be able to maintain their position up until and / or during the peeling operation, which may cause problems with holding by the arm or cause the wafers to come into contact with each other, resulting in defects (scratches, chips). In this case, the temperature control unit adjusts the temperature of the hot water to increase the adhesive strength. As an example, the softening state of the adhesive is adjusted by not raising the temperature of the hot water too much.

[0020] As described above, the fourth wafer peeling and cleaning apparatus is configured to adjust the temperature of the hot water according to the load during peeling, thereby improving processing capacity and reducing the frequency of defects.

[0021] A fifth wafer peeling and cleaning apparatus disclosed in the present specification is a wafer peeling and cleaning apparatus which is a first to third wafer peeling and cleaning apparatus, further comprising a hot water tank configured to store hot water and immerse at least the slice base in the hot water so as to adjust the adhesive strength of the adhesive bonding the wafer and the slice base, and a temperature control unit configured to control the temperature of the hot water, wherein a judgment criterion for the magnitude of the load during the peeling is predefined in at least two or more stages, and depending on the stage to which the magnitude of the load belongs, the temperature control unit adjusts the temperature of the hot water, or the peeling operation is performed again, or the peeling operation is stopped and first alert information is generated.

[0022] In the fifth wafer peeling and cleaning apparatus, a plurality of stages of judgment criteria for the magnitude of the load during peeling are prepared, and the corresponding process is divided for each stage. An example of the judgment criteria prepared for a plurality of stages is a case where the judgment criteria includes a first threshold, a second threshold, and a third threshold. In a specific operation, the magnitude of the load is assigned to each stage of the following: less than the first threshold (normal: NM), more than the first threshold and less than the second threshold (abnormal: AOM1), more than the second threshold and less than the third threshold (abnormal: AOM2), and more than the third threshold (abnormal: AOM3), and the subsequent process is divided. Specifically, in the case of AOM1, the peeling operation is executed again, in the case of AOM2, the temperature of the hot water is adjusted, and in the case of AOM3, the peeling operation is stopped and first alert information is generated. As the first alert information, for example, a so-called "operator call" that notifies of a peeling failure is exemplified.

[0023] According to the fifth wafer peeling and cleaning apparatus, a preset appropriate process is performed according to the magnitude of the load during peeling, thereby improving the processing capacity and reducing the frequency of defects.

[0024] A sixth wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus which, in the second or third wafer peeling and cleaning apparatus, generates second alert information based on the magnitude of the load when passing through the slit.

[0025] As mentioned above, even if linking occurs, the wafer may still pass through the slit. However, that wafer, or the next wafer that was (supposed to be) waiting for the peeling operation, may have scratches, chips, etc. The second alert information records and / or notifies that there was an abnormal load when passing through the slit, and this allows the wafer with a possible defect to be identified.

[0026] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the wafer to be peeled off from the slice base may be referred to as the first, second, ..., nth, etc. The first wafer is not a term that refers to a specific wafer set in the equipment, but is a relative term that refers to the first wafer (to be) peeled off by the peeling unit among the set wafers. In other words, after the first wafer is peeled off from the slice base, the wafer that was the "second" immediately before becomes the new "first," and the subsequent wafers that are peeled off in sequence also move up to the second, third, ..., n-1th wafer, respectively. Finally, the last "first" wafer is peeled off, and the peeling operation series ends. In addition, in this specification, the term "surface of a wafer" refers to the substantially circular front surface (back surface) that is the main surface of a disk-shaped wafer, and the term "circumferential surface of a wafer" refers to the side surface of the wafer. In addition, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower limit and upper limit. The embodiment described below is an example of a concrete embodiment of the technical concept. The technical concept does not limit the material, shape, structure, arrangement, etc. of the components to the embodiment described below. The drawings are schematic.

[0027] Fig. 1 is an overall plan view of a wafer separating and cleaning apparatus 1 according to the present invention, and Fig. 2 is a plan view of a separating apparatus 114. The wafer peeling and cleaning apparatus 1 of this embodiment is configured with a rough cleaning unit 10, a wafer peeling and cleaning unit 100, a transport unit 310, a single wafer cleaning unit 350, a detection unit 400, and a recovery unit 500 as main components.

[0028] The rough cleaning section 10 shower-cleans the wafers W (wafers W bonded to slice bases S) that have been cut from an ingot using a wire saw and are in a batch state, to remove slurry that has adhered to the wafers during cutting. The rough cleaning section 10 is equipped with a rough cleaning device 12 that cleans the wafers W. In the rough cleaning device 12, the wafers W are immersed in a cleaning solution with the mounting plate M on the upper side and the slice grooves on the lower side, and are cleaned. When cleaning is performed, the wafers W are shaken up and down to create a water flow in the grooves. When cleaning is completed, the wafers W are removed from the rough cleaning section 10 and transported to the wafer separation section 100 by a lifter.

[0029] The wafer peeling unit 100 peels wafers W in a batch state one by one from the slice base S to produce single wafers. The wafer peeling unit 100 mainly comprises a hot water bath 112, a peeling device 114, and a delivery device 118. The delivery device 118 receives the wafer W peeled off from the slice base S by the peeling device 114, and delivers it to the shuttle conveyor 312 of the transport unit 310.

[0030] The transfer unit 310 receives the wafers W separated into individual wafers by the wafer separation unit 100, and transfers them to the individual wafer cleaning unit 350. The transfer from the transfer unit 310 to the individual wafer cleaning unit 350 is performed by a shuttle conveyor 312.

[0031] The single wafer cleaning section 350 cleans the single wafers W one by one. The single wafer cleaning section 350 is mainly composed of a brush cleaning section 352, a pre-rinse section 354, and a rinse section 356. The brush cleaning section 352 brush-cleans the wafers W conveyed thereto while spraying cleaning liquid on the rear and front surfaces thereof. After cleaning, compressed air is sprayed to drain the cleaning liquid so as not to carry it over to the next process. The wafers W that have been brush-cleaned are conveyed to the pre-rinse section 354.

[0032] The pre-rinse section 354 performs brush cleaning using a rotating brush while spraying pre-rinse liquid from a pre-rinse liquid nozzle onto the rear surface of the transported wafer W. After cleaning, compressed air is sprayed onto the wafer W to drain the liquid. The wafer W is then transported to the rinse section 356.

[0033] The rinsing unit 356 uses a rotating brush to perform brush cleaning while spraying rinsing liquid from a rinsing liquid nozzle onto the rear surface of the wafer W. After cleaning, the wafer W from which the liquid has been drained is transferred onto the round belt conveyor 411 of the detection unit 400 and conveyed to a predetermined receiving position of the detection unit 400.

[0034] The detection unit 400 detects each of the cleaned wafers W for cracks, chips, and the presence or absence of remaining adhesive, and measures the thickness of each of the wafers W. After the detection, the wafers W are delivered to the wafer transport robot 508 of the recovery unit 500.

[0035] The wafer transport robot 508 is an articulated robot, and a rotatable hand unit 520 is provided at the tip of the hand unit 520. The wafer W is transported while being suction-held by a suction pad 522 provided at the tip of the hand unit 520. The recovery unit 500 separates adhesive remaining wafers and defective wafers (cracked wafers, chipped wafers, wafers with defective thickness, or scraps). The recovery unit 500 is mainly composed of two wafer recovery units 502A and 502B that recover normal wafers, a defective wafer recovery unit 504 that recovers defective wafers, and an adhesive remaining wafer recovery unit 506 that recovers adhesive remaining wafers.

[0036] The wafer transport robot 508 receives the wafers W from the detector 400, and sorts and stores the wafers W into the cassettes of the wafer recovery units 502A, 502B, 504, and 506 based on the detection results.

[0037] Next, the details of the wafer separation unit 100 will be described. Fig. 2 is a plan view of the separation device 114, which is one of the main devices of the wafer separation unit 100. Fig. 3 is a front view of the separation device 114 and the hot water bath 112. Fig. 4 is a front view of the delivery device 118, which is one of the main devices of the wafer separation unit 100.

[0038] First, the configuration of the hot water tank 112 will be described (FIG. 3). The hot water tank 112 is formed in a rectangular box shape. Hot water 120 is stored inside the box. The wafer W to be peeled off from the slice base S is set in the hot water tank 112. In the hot water tank 112, the slice base S bonded to the wafer W is immersed in the hot water 120. At this time, most of the wafer W protrudes outward (protrudes upward) from the surface of the hot water 120. The hot water tank 112 is for adjusting the adhesive strength of the adhesive bonding the wafer W and the slice base S. Therefore, it is sufficient that at least the slice base S and the contact point between the slice base S and the wafer W are in the hot water 120. As will be described later, since the surface of the wafer W is supported by the arm 190 during the peeling operation, it is preferable that most of the wafer W protrudes outward from the surface of the hot water 120 and is outside the hot water 120.

[0039] Hot water or water is supplied to the hot water tank 112 from above, and a heater H for heating the hot water 120 is installed inside, and a water level sensor 121 for managing the water level of the hot water 120 is installed at the top. The heater H and the water level sensor 121 constitute a temperature control unit for adjusting the temperature of the hot water.

[0040] A pulse-type level sensor is preferable for the water level sensor 121. A pulse-type level sensor irradiates an ultrasonic pulse onto the upper surface of the hot water 120, which is the surface to be measured, and measures the time it takes for the pulse to be reflected and returned. The pulse-type level sensor can accurately detect the amount of hot water 120 that has decreased due to evaporation of the water in the hot water tank 112, etc. The control device can supply a predetermined amount of water each time the hot water 120 evaporates and the water level drops. When absorbing water, the temperature adjustment unit can energize the heater H to reduce the temperature change of the hot water 120. The hot water tank 112 may also be equipped with stirring blades (not shown). By circulating the hot water 120 with the stirring blades to create a flow, the occurrence of temperature unevenness can be further suppressed. Hot water or water is supplied to the hot water tank 112 from near the center vertically above the wafer W (from the opposite side of the slice base S with respect to the center of the wafer W) as indicated by an arrow K in FIG. 6 described later.

[0041] Next, the configuration of the peeling device 114 will be described (mainly Figs. 2 and 3). The peeling device 114 is a device that peels off the wafers W set in the hot water bath 112 one by one from the slice base S. As shown in Figs. 2 and 3, a pair of first guide rails 136, 136 are arranged in the vicinity of the right side of the hot water bath 112 along the longitudinal direction of the hot water bath 112. A first slide table 140 is slidably supported on the first guide rails 136, 136 via linear guides 138, 138.

[0042] A nut member 142 is fixed to the underside of the first slide table 140, and the nut member 142 is screwed onto a threaded rod 144 disposed between a pair of first guide rails 136, 136. Both ends of the threaded rod 144 are supported so as to be freely rotatable, and a first feed motor (not shown) installed at one end of the first guide rails 136, 136 is connected to one end of the threaded rod 144. The threaded rod 144 rotates when the first feed motor (not shown) is driven, and as a result, the first slide table 140 moves along the first guide rails 136, 136.

[0043] A peeling unit 150 for peeling the wafer W from the slice base S is provided on the first slide table 140. The peeling unit 150 includes an arm guide 152 and an arm 190 supported by the arm guide 152 so as to be vertically slidable. The arm 190 can be moved vertically at a predetermined speed by a servo motor (not shown). The tip of the arm 190 is connected to a pad support plate 198. A pair of first and second peeling suction pads 200, 201 are disposed on the pad support plate 198 with a predetermined gap between them. The first and second peeling suction pads 200, 201 vacuum-suck and hold the wafer W (suction-hold). Further, the pad support plate 198 is configured so as to be able to give swinging motion to the first and second peeling suction pads 200, 201 in the front-rear direction.

[0044] The procedure for peeling off the wafer W from the slice base S by the first and second peeling suction pads 200, 201 is as follows. First, the surface of the wafer W set in the hot water bath 112 is suction-held by the first and second suction pads 200, 201 for peeling. Next, the first and second suction pads 200, 201 for peeling are oscillated a predetermined number of times in the front-rear direction (the direction along the surface of the wafer W). Here, the adhesive bonding the wafer W to the slice base S is softened because it is immersed in the hot water 120. Therefore, the wafer W is peeled off from the slice base S by being oscillated multiple times.

[0045] The load applied to the arm 190 when peeling off the wafer W from the slice base S is detected by a load detection unit including a strain gauge 192 (see FIG. 3). In addition to or instead of the strain gauge 192, the load detection unit may detect the magnitude of the load from the load current of the servo motor that drives the arm 190.

[0046] When the wafer W is peeled off from the slice base S, the servo motor is driven, and the first and second peeling suction pads 200, 201 move upward at a predetermined speed while holding the peeled off wafer W. In other words, the wafer W is transported by the arm 190. When the first and second peeling suction pads 200, 201 are raised at a constant speed by the servo motor, the load (rising load) of the arm 190 during the transfer of the wafer W is detected by the load detection unit.

[0047] Next, the load during peeling detected by the load detection unit will be described. As described above, the load detection unit also detects the load during the transfer of the wafer W, but this will be described in detail later.

[0048] The magnitude of the load during peeling correlates with the adhesive strength between the wafer W and the slice base S. Before the peeling step, the wafer W is preferably supported to be attached to the slice base S so as to stand on its own, and once the peeling operation is started, the wafer W is preferably easily separated from the slice base S by the stress from the arm 190. Such a preferable state is realized by adjusting the adhesive force between the slice base S and the wafer W. In other words, if the adhesive force is not appropriately adjusted, specifically, if the adhesive force is weak, the wafer W may lift up or tilt from the slice base before the peeling operation, causing the attitude of the wafer W to change from the intended state and causing damage during peeling. Conversely, if the adhesive force is strong, peeling may not be easy, and the peeling operation may need to be repeated, or the wafer W may be damaged during peeling.

[0049] This adhesive force can be indirectly monitored by detecting the load of the arm 190 during peeling. If the magnitude of the load is abnormal (too small or too large), it suggests that the wafer W may have a defect such as a scratch or chip. Data on the load of the arm 190 during peeling can be used to distinguish wafers W that may have a defect (have an inherent defect) and can be used as an index for operating the equipment. As a result, defects are less likely to occur, the quality of the single wafer W is improved, and processing capacity is improved.

[0050] If the load during peeling is greater than the expected value, it is assumed that the adhesive force between the wafer W and the slice base S is too strong. If the adhesive force is too strong, the peeling operation may take a long time, the peeling operation may have to be repeated, or even peeling may not be completed and an operator may have to deal with the problem, resulting in a decrease in processing capacity. In this case, the temperature control unit may adjust the temperature of the hot water 120 so as to reduce the adhesive force. Whether to increase or decrease the temperature of the hot water 120 can be appropriately determined depending on the properties of the adhesive. For example, if the load is too large, the temperature of the hot water 120 may be increased by the heater H to further soften the adhesive.

[0051] On the other hand, if the load during peeling is smaller than the expected value, it is assumed that the adhesive strength between the wafer W and the slice base S is too weak. If the adhesive strength is too weak, the wafer W may not be able to maintain its position up until and / or during the peeling operation, resulting in defects (scratches and chips). In this case, the temperature control unit may adjust the temperature of the hot water so as to increase the adhesive strength. As an example, the softening state of the adhesive may be adjusted by not raising the temperature of the hot water too much (hot water or water with a lower temperature may be added).

[0052] Regarding the load during peeling, if the increasing load is equal to or exceeds a predetermined value and the adhesive force is detected as being too strong, the peeling operation may be stopped at that point without forcing the peeling, and the peeling operation may be restarted, an operator may be called, etc. This can protect the wafer W from significant damage.

[0053] Furthermore, a graded judgment criterion may be set in advance for the load during peeling, and the subsequent processing may be changed according to this. The judgment criterion may be one or more. For example, the magnitude of the load may be compared with the judgment criterion, and based on this, peeling may be performed again, the peeling operation may be stopped and alert information may be generated, or the temperature adjustment unit may be operated to adjust the temperature of the hot water 120.

[0054] It is preferable that the judgment criteria are determined in advance in a plurality of stages, and subsequent processing is associated with each stage. For example, the judgment criteria may include a first threshold, a second threshold, and a third threshold. As an example of operation, the magnitude of the load is assigned to each stage of the following stages: below the first threshold (normal: NM), above the first threshold and below the second threshold (abnormal: AOM1), above the second threshold and below the third threshold (abnormal: AOM2), and above the third threshold (abnormal: AOM3). If the load belongs to AOM1, the stripping operation is executed again; if the load belongs to AOM2, the temperature of the hot water 120 is adjusted; if the load belongs to AOM3, the stripping operation is stopped and first alert information is generated. The first alert information may include an operator call to inform of a stripping failure.

[0055] Returning to the description of the configuration of the peeling device 114, after the wafer W has been peeled off, the first and second peeling suction pads 200, 201 stop at a predetermined delivery position. The wafer W transferred to the delivery position is delivered to the delivery device 118 (FIG. 4), and then transferred to the shuttle conveyor 312 by the delivery device 118, and then transported to the next process by the shuttle conveyor 312. On the other hand, after the transfer of the wafer W, the first and second separation suction pads 200, 201 are driven by the servo motor to move downward and return to their original separation operation positions.

[0056] Next, the anti-fall plate 214 (mainly FIG. 2) will be described. The wafer W, which is sucked and held by the first and second peeling suction pads 200, 201, is subjected to a rocking motion and peeled off from the slice base S. However, depending on the adhesive force between the slice base S and the wafer W, the wafer W may peel off from the slice base S even before the rocking motion is applied.

[0057] If peeling occurs earlier than expected and the wafer W tilts or falls over, this may cause problems in suction holding by the first and second peeling suction pads 200, 201. The fall prevention plate 214 is disposed in front of the first wafer W (between the wafer W and the arm 190 in a plan view). The fall prevention plate 214 can prevent the wafer W from falling over. The fall prevention plate 214 is provided on the support plate 202, and can swing together with the first and second peeling suction pads 200, 201.

[0058] The first and second peeling suction pads 200, 201 move up and down through a passage 214a formed in the tilting stopper plate 214. A one-piece pick-up adjustment unit 216 (FIG. 2) is provided above the tilting stopper plate 214. The wafer W peeled off from the slice base S is further transported to a predetermined delivery position through a slit provided in the one-piece pick-up adjustment unit 216.

[0059] 10 is an explanatory diagram of the operation of the one-piece pickup adjustment section 216. The one-piece pickup adjustment section 216 includes a slit SLT whose width is adjusted so that the wafers transferred by the delamination unit 150 can pass through it one by one.

[0060] When the delaminated wafer is transferred by the arm 190, the next wafer (second wafer) waiting to be delaminated may come into contact with a part of the wafer, causing the surfaces to adhere to each other via the water, and the second wafer may be pulled and transferred together (linking). The single-piece pickup adjustment unit 216 blocks the lifting of the second and subsequent wafers W that are pulled and transferred by using the slit SLT. At this time, the second wafer hits the slit and falls, which can result in damage such as scratches on the surface, cracks or chips, chipping, microcracks, etc.

[0061] In the wafer peeling and cleaning apparatus of this embodiment, the occurrence of blocking by the single-piece pickup adjustment unit 216 can be monitored by the load of the arm 190 during the transfer of the wafer W. The following describes in detail how the load detection unit detects the load during the transfer of the wafer W.

[0062] First, the load detection unit detects the load when the wafer W, which is held by the arm 190 and transported, passes through the slit. If a load different from normal, for example a larger load, is detected when passing through the slit SLT, there is a high possibility that a defect has occurred in the wafer W or the "second" wafer W that is (supposed to be) peeled off next. When linking occurs, a larger load than usual is applied when passing through the slit SLT. In many cases, even if linking occurs, the wafer W can still pass through the slit SLT, and therefore it may be impossible to distinguish the wafer W from a wafer W for which peeling has been normally completed. However, as described above, there are many cases in which some kind of defect (scratches, chips) occurs in the wafer W before and after the occurrence of linking.

[0063] As already explained, the load detection unit also detects the load during peeling of the wafer W. The load data obtained by the load detection unit is typically time-vs-load data. From this data, the load during peeling and the load during passing through the slit SLT are extracted. In other words, if there is a peak or the like in the above data, this can be attributed to the load during peeling or the load during passing through the slit SLT.

[0064] As an example, the attribution of peaks, etc. is preferably performed in the following procedure. First, the lifting (transporting) speed of the wafer by arm 190 and the number of oscillations and time are configured to be constant. Then, by measuring the time from the signal to start the peeling operation, the current position of the wafer W can be grasped. Once the current position is grasped, since the initial position of the first wafer and the position of the single-piece pickup adjustment unit 216 are fixed, each detected peak, etc. can be attributed to that during peeling or that during passage through the slit SLT from the time-to-load data.

[0065] The load detection unit detects the load when the wafer is peeled and when it passes through the slit, and the history of stress applied to a single wafer from when it is peeled to when it passes through the slit can be indirectly determined from the load on arm 190, thereby obtaining basic information for detecting inherent defects and identifying the process in which a defect may have occurred.

[0066] The wafer separating and cleaning equipment may generate second alert information based on the magnitude of the load when passing through the slit SLT. The second alert information includes detection information of the linking state. As mentioned above, when linking occurs, the wafer W often passes through the slit. However, that wafer W, or the second (or subsequent) wafer W that was (supposed to be) waiting to be peeled, may have scratches, chips, etc. The second alert information records and / or notifies that there was an abnormal load when passing through the slit SLT. This makes it possible to identify the wafer W that may have a defect.

[0067] Furthermore, the second alert may include an "operator call" due to an abnormal load in addition to or instead of the detection information of the linking state. Furthermore, the transfer of the wafers W may be stopped based on the magnitude of the load. Furthermore, based on criteria divided into a plurality of preset stages, a process corresponding to each stage may be performed. For example, the generation of the second alert including the detection information of the linking state and the operator call may be selected and executed based on the magnitude of the load.

[0068] Here, the description of the peeling device 114 is temporarily completed, and next, the schematic configuration of the delivery device 118 that receives the wafer W from the peeling device 114 will be described with reference to Fig. 4. The delivery device 118 is a device that receives the wafer W, which has been peeled off from the slice base S by the first peeling suction pad 200 of the peeling device 114, from the first peeling suction pad 200, and delivers it to the shuttle conveyor 312. As shown in Fig. 4, the delivery device 118 is provided on the second slide table 240, and the second slide table 240 is slidably supported on the second guide rails 236, 236 via second linear guides 238, 238. The second slide table 240 is screwed into a second screw rod 244 disposed between the pair of second guide rails 236, 236. Both ends of the second screw rod 244 are supported so as to be freely rotatable, and one end of the second screw rod 244 is connected to a second feed motor (not shown) installed at one end of the second guide rails 236, 236. The second screw rod 244 moves along the second guide rails 236, 236 when the second feed motor (not shown) is driven.

[0069] A support column 274 is provided vertically on the second slide table 240. A support frame 276 is provided vertically on the top of this support column 274, and a rotary actuator 278 for turning is provided horizontally on the support frame 276. A drive gear 280 is engaged with the output shaft of the rotary actuator 278 for turning, and a driven gear 282 is engaged with the drive gear 280.

[0070] A support plate 296 is fixed to the tip of the rotating arm 294. A delivery suction pad 300 is provided on the support plate 296. The wafer W peeled off by the first and second peeling suction pads 200, 201 of the peeling device 114 is transported to a predetermined delivery position, and then delivered to the delivery suction pad 300.

[0071] The wafer W peeled off from the slice base S is lifted up while being held by suction on the first and second peeling suction pads 200, 201 and is transferred to a predetermined delivery position. The delivery suction pad 300 waits at the delivery position. The delivery position is coaxial with the axis of the delivery suction pad 300.

[0072] When the wafer W is transferred to the delivery position, the delivery suction pad 300 advances a predetermined distance toward the wafer W at the delivery position. As a result, the delivery suction pad 300 comes into close contact with the back surface of the wafer W. Next, the delivery suction pad 300 is driven, and the wafer W is suction-held by the delivery suction pad 300. A touch sensor (not shown) provided on the delivery suction pad 300 side detects that the wafer W has been suction-held by the delivery suction pad 300. Then, this detection signal causes the first peeling suction pad 200 to release its vacuum suction, that is, air is allowed to flow in. As a result, the wafer W is delivered from the first peeling suction pad 200 to the delivery suction pad 300.

[0073] The delivery suction pad 300, which has received the wafer W, retreats from the first separation suction pad 200. The first separation suction pad 200, which has received the wafer W, starts to descend and returns to its original peeling operation position. When the delivery suction pad 300 retreats, the pivot arm 294 pivots 180°. As a result, the wafer W is transferred to a position above the shuttle conveyor 312. After the direction-changing rotary actuator 292 is driven, the delivery suction pad 300 advances a predetermined amount toward the shuttle conveyor 312. As a result, the wafer W is placed on the shuttle conveyor 312. When the wafer W is placed on the shuttle conveyor 312, the drive of the delivery suction pad 300 is stopped. Then, the delivery suction pad 300 retreats from the shuttle conveyor 312.

[0074] After the wafer W has been delivered, the delivery suction pad 300 returns to the original delivery position by performing the above-mentioned reverse operation. Meanwhile, the shuttle conveyor 312 to which the wafer W has been delivered is driven by a driving means (not shown) to transport the delivered wafer W to the next process. The driving of the wafer peeling unit 100 is automatically controlled by a control device (not shown), and each component device operates based on a drive signal output from the control device.

[0075] Next, a detailed description will be given of a method for peeling the wafer W in the single-wafer peeling section 100. Before starting the operation, the first slide table 140 on which the peeling unit 150 is installed is located at a peeling operation start position of the first guide rail 136.

[0076] The wafers W multi-cut by the wire saw are set on the work holder 122 installed in the hot water bath 112. As a result, the slice bases S to which the wafers W are bonded are immersed in the hot water 120 stored in the hot water bath 112. The wafers W may be set manually by an operator or automatically by a manipulator or the like. When the second slide table 240 is positioned at the starting position for the transfer operation, the peeling operation of the wafer W is started.

[0077] Fig. 5 is an enlarged side view of the main part showing the details of the peeling unit. Fig. 6 is an enlarged front view of the main part of the peeling unit. The anti-fall plate 214 is composed of a laminated plate in which a resin pressing plate 214-1 and a stainless steel plate 214-2 are laminated in this order from the reference surface side, with the surface of the wafer W serving as the reference surface. The stainless steel plate 214-2 ensures the flatness of the pressing plate 214-1.

[0078] The first peeling suction pad 200 is disposed so that its center coincides with the center of the wafer W. The second peeling suction pad 201 is disposed below the first peeling suction pad 200. The first peeling suction pad 200 is a flat vacuum pad suitable for transporting a workpiece having a flat surface. The first peeling suction pad 200 has a stronger suction force than the second peeling suction pad 201. The second peeling suction pad 201 is a bellows-type vacuum suction pad that expands and contracts in the axial direction.

[0079] The first and second peeling suction pads 200, 201 suction-hold the wafer W as follows. First, the second peeling suction pad 201 comes into contact with the surface of the wafer W. The second peeling suction pad 201 (1) suctions the wafer W below its center, and (2) because it is a bellows-type vacuum suction pad, it pulls the base of the wafer W toward the anti-tilting plate 214, centered around the vicinity of the slice base S. This ensures that the peeling operation begins reliably and efficiently.

[0080] The wafer W is bonded to the slice base S with an adhesive, and after being placed on the upper side relative to the mounting plate M, is set in the workpiece holder 122 of the hot water bath 112. The adhesive bonding the wafer W to the slice base S is softened by being immersed in the hot water 120. The slice base S side is immersed in hot water 120 stored in the hot water tank 112, and the opposite end (most of the wafer W) is held so as to protrude above the water surface, to soften the adhesive. This allows the wafer W to be peeled off from the slice base S. The wafer W is not entirely immersed in the hot water 120, but is held so as to have most of it protruding outside the water surface.

[0081] The parallel wafers W are arranged approximately parallel to each other with their surfaces facing each other. If the wafers W tilt, water may get between the wafers W, causing them to stick to each other. In particular, the ends of the wafers W opposite to the end held by the slice base S are not supported by the slice base S and are in a free state, so that the wafers W are likely to come into contact with each other even if they are tilted even slightly, and water vapor (water) is likely to get in due to the effect of the hot water 120, making adsorption likely to occur.

[0082] If adjacent wafers W stick to each other, this will be an obstacle when peeling them one by one. For this reason, in the past, air was blown between the wafers W to separate the stuck wafers W and perform the peeling operation. In order to improve the processing capacity, air was also simultaneously supplied not only between the first and second wafers, but also between the second and subsequent wafers waiting for the peeling operation (the second and third wafers, the third and fourth wafers, etc.), and preparations for peeling were performed simultaneously. In the wafer peeling and cleaning apparatus of this embodiment, a pair of air nozzles 80, 81 are arranged near the slice base S as air supply units for blowing and supplying air as described above. These air supply units are sometimes called "air cutters."

[0083] The air nozzles 80, 81 are provided on both sides of the wafer W so as to face each other across the wafer W. That is, a pair of air nozzles 80, 81 are arranged facing each other in a direction substantially along the surface of the wafer W across the wafer W. The air nozzles 80, 81 are also installed so as to forcefully blow air from below to above the two sides of the wafer W. In other words, the direction of the air blowing is a direction along the surface of the wafer W extending from the slice base S, and is also a direction (from below to above) from the water surface toward the direction in which the wafer W protrudes. The direction (from below to above) from the water surface toward the direction in which the wafer W protrudes is, in other words, a direction from the slice base S side toward the wafer W side.

[0084] The surface of the wafer W is required to be smoother and larger in diameter, so that the wafers W are often in contact with each other, and when they are in contact, the adhesion force is often higher than in the past. In such an environment, simply blowing air into the gaps between the wafers may not be sufficient to separate the wafers W that are in contact or in close contact with each other.

[0085] Conventional air nozzles have nozzle holes of about φ1mm that blow air to one point. Therefore, if the position of the gap between the wafers shifts, the air is not blown to the intended position, which can lead to poor peeling performance. One of the factors that can cause the gap between the wafers to shift is the change in wafer position due to the adhesive softening.

[0086] In addition, when air is supplied not only between the first and second wafers, but also between the second and third wafers, the third and fourth wafers, and so on, adjacent wafers may also vibrate due to the air. This is especially likely to occur near the edge of the opposite side of the slice base. In this case, the second wafer may be pushed by the vibration of the third and subsequent wafers, and the first and second wafers may end up coming into contact with each other. This can result in a decrease in processing capacity.

[0087] In order to solve the above problems, the wafer peeling and cleaning apparatus of this embodiment has the following features regarding the air supply unit. First, the nozzle holes (air outlets) of the air nozzles 80, 81, which are the air supply parts, are slit-shaped (long hole-shaped), and the longitudinal direction of the holes is approximately parallel to the direction (T direction) in which the faces of the wafers W face. This makes it possible to blow air into the gaps between the wafers W even if the positions of the wafers W change slightly. In other words, robustness has been improved. Next, the nozzle holes are arranged in parallel in the circumferential direction of the wafer W (specifically, arranged above and below), and are arranged in two rows as shown by the arrows F1, F2, G1, and G2, respectively, and further, the length in the longitudinal direction and / or the length in the lateral direction of one of the nozzle holes arranged in the air nozzles 80 and 81 is shorter than the other. As a result, even if air is simultaneously blown between the second and subsequent wafers, the first wafer W and the second wafer W can be reliably separated. Therefore, the peeling operation of the first wafer can be reliably performed. Furthermore, since air can be simultaneously blown to the second and subsequent wafers W, the processing capacity (number of wafers) per hour is also improved.

[0088] Next, the shape of the nozzle holes provided in the air nozzles 80 and 81 will be described. Fig. 7 is a perspective view showing air nozzle 81. Fig. 11(a) is a plan view showing the shape of air nozzle 81. Nozzle holes 81-1 and 81-2 are arranged such that their longitudinal direction is along the direction of arrow T, which is the thickness direction of wafer W (a direction substantially parallel to the direction in which the surface of wafer W faces). As they are elongated in the direction of arrow T, air can be blown over a wider range in the direction of arrow T. This makes it easier to blow air simultaneously between the first and second wafers and between the second and subsequent wafers.

[0089] Moreover, the nozzle holes 81-1 and 81-2 are arranged in parallel along the circumferential direction of the wafer W. Although not shown, the shape and arrangement of the nozzle holes in the air nozzle 80 are similar to those of the air nozzle 81. It is preferable that the shapes of the nozzle holes of the air nozzles 80 and 81 arranged opposite each other with the wafer W in between are the same. In this way, the wafers W can be separated more uniformly.

[0090] Since the nozzle holes 81-1 and 81-2 are elongated (slit-shaped), the nozzle holes 81-1 and 81-2 blow band-shaped air, so that even if the wafer W is misaligned (particularly in the direction of the arrow T), the two wafers can be satisfactorily separated without contact or linking, and the second and subsequent wafers can be simultaneously separated in preparation for peeling. Furthermore, the improvement in separation performance shortens the time required for the peeling operation, and the wafer W can be transported to the single wafer cleaning unit 350 by the delivery device 118 without being damaged, thereby improving the overall manufacturing efficiency.

[0091] Nozzle hole 81-2 (FIG. 7) corresponding to G1, which is the lower side in FIG. 6, is arranged in a position (position in the T direction) where air can be mainly blown between the first and second sheets. There is no particular limitation on whether the nozzle hole used to blow air between the first and second sheets is arranged above or below (G1 or G2), but it is preferable to use nozzle hole 81-2 closer to the water surface (lower side) to mainly blow air between the first and second sheets. The side (lower side) closer to the water surface of the hot water 120 means the side closer to the slice base S. The wafers W are separated one by one and adhered and held in the slice base S. In principle, the width of the gap is maintained. If the nozzle hole that blows from near the water surface closer to the slice base S is used mainly to blow air between the first and second wafers, the first and second wafers can be separated more reliably.

[0092] In FIG. 11(a), the length of the nozzle hole 81-2 in the longitudinal direction (T direction) and the length (width) in the lateral direction are each configured to be shorter than those of the nozzle hole 81-1 arranged in parallel. As a result, when air is supplied to the nozzle holes 81-1 and 81-2 at the same air pressure, the air blown out from the nozzle hole 81-2 is relatively stronger. It is not necessary to configure both the longitudinal direction and the lateral direction to be short, and it is sufficient if one of them is the same as the nozzle hole 81-1 as long as the other is shorter. In particular, when the length in the longitudinal direction is shorter, it is preferable because it is easier to blow air only to the gap between the first and second wafers.

[0093] Nozzle hole 81-2 is adjusted so that the air blown is aimed at the gap between the first and second wafers W. On the other hand, nozzle hole 81-1 is adjusted to a position where air can be blown not only between the first and second wafers W, but also between the second and subsequent wafers. When configured in this manner, air is blown from both nozzle holes 81-1 and 81-2 between the first and second wafers W. As a result, the air hits the gap between the first and second wafers W more strongly.

[0094] 8 is an explanatory diagram showing the action of air during peeling. When the wafers W are peeled one by one, air is blown from air nozzles 80 and 81 along the surface of the wafer W (in the directions indicated by arrows F1, F2, G1, and G2, see FIG. 6) from both sides of the wafer W, aiming at the gaps between the first wafer W1 to be peeled and the second and subsequent wafers W2, W3, W4, and W5 adjacent thereto. The air is blown in the direction from the water surface side of the wafer W toward the protruding side (from the bottom to the top). There is no limit to how many wafers the air should be blown between the second and subsequent wafers, and the air may be blown up to the wafers W6 and W7, or between the wafers thereafter.

[0095] The strongest air blowing force is supplied between the first wafer W1 and the second wafer W2. At the same time, air is blown between the second wafer W2 and the third wafer W3, and between the third wafer W3 and the fourth wafer W4, improving processing capacity. However, since the adhesive bonding the wafer W and slice base S may soften over time while the peeling operation is being performed, the number of wafers to be blown or the amount of air blown may be reduced as the peeling operation progresses.

[0096] For example, as shown by arrows L1, L2, L3, and L4, the air blow supply may be gradually lightened between the second and subsequent wafers. When peeling off one wafer W, the air may be blown strongly between the first and second wafers, and gradually lightened between the second and third wafers and thereafter. If the air is blown strongest between the first and second wafers, it may be blown with the same strength for the second and subsequent wafers, or it may be gradually weakened.

[0097] In particular, by blowing air between the first wafer W1 and the second wafer W2, and between the second wafer W2 and the third wafer W3, it is possible to prevent the next standby wafer W (second wafer) after the lifted wafer W from coming into contact with the next standby wafer W (third wafer). This can improve the efficiency of the peeling operations in sequence.

[0098] 11(b) is a plan view of another embodiment of the nozzle hole. The nozzle hole 81-3 has a short-side length (width) that is wider at a position corresponding to the gap between the first and second wafers. On the other hand, the width is relatively narrower at positions corresponding to the gaps between the second and subsequent wafers. When air at a predetermined pressure is supplied to the nozzle hole 81-3, the air is blown out more strongly from the wider portion. In Fig. 11(b), the length (width) in the short direction increases continuously, but it may increase in stages. If air is blown more strongly between the first and second sheets, the shape of the long hole is not limited. On the other hand, if the long hole is made rectangular as in Fig. 11(a), it is easy to process, which tends to be advantageous in terms of cost.

[0099] Next, the imaging section including the camera 123 will be described. As shown in FIG. 6, a camera 123 is disposed in the peeling device 114. The camera 123 captures an image of the state during peeling of the wafer W. Specifically, the camera 123 captures an image of an area including the gap between the first and second wafers. Based on the obtained image, the width of the gap between the first and second wafers is measured by image processing. In this specification, a set of hardware and software including the camera 123 and realizing a function of measuring the width of the gap between the first and second wafers from the acquired image is defined as an imaging unit.

[0100] The imaging unit monitors the gap between the first and second wafers W. Essentially, a gap of a specified width is required between the first and second wafers W. However, for some reason, the posture of the wafer W may change from the intended state, causing the first and second wafers to come into contact. When the first and second wafers come into contact, the above-mentioned linking state may occur. By monitoring the gap with the imaging unit, the occurrence of the above-mentioned malfunctions may be prevented, recorded, or notified.

[0101] The wafer peeling and cleaning apparatus of this embodiment starts the peeling operation of the first wafer when the gap width acquired from the image satisfies a predetermined criterion. The predetermined criterion is a reference value that can determine that the first and second wafers are sufficiently separated. Typically, it is a predetermined numerical range for the gap width.

[0102] The width of the gap can be measured from an image acquired when air is blown and supplied. If the width of this gap satisfies the above criteria, it is presumed that the above-mentioned defect has not occurred (i.e., the first and second wafers are separated). After this is confirmed, the operation of peeling the first wafer is started. As a specific example, the gap between the wafers W is often about 0.1 mm, for example, and the criteria may be set in a range including this. The imaging unit typically detects this gap in 20 ms.

[0103] 9 is a schematic diagram of an image captured above the wafer W by the camera 123. The wafer W is held in a state where it is adhered to a slice base S immersed in the hot water bath 112, with most of it protruding above the water surface. The camera 123 is positioned so that it can capture an image of the area including the circumferential surface of the first wafer, the circumferential surface of the second wafer, and the gap between them, among the parts protruding above the water surface.

[0104] Of the parts protruding from the water surface, the area more suitable for imaging is the part held by the slice base S, the circumferential surface of the wafer W at a position approximately symmetrical with respect to the center of the wafer W, and the area including the gap therebetween. In short, it is the upper half of the wafer W. The reason for this is as follows.

[0105] First, contact between wafers W is likely to occur at the portions protruding from the water surface. This is because the wafers are adhesively held at a certain distance from each other on the slice base S. Therefore, contact between wafers is likely to occur at the portion (upper side) that is symmetrical across the center (with the center as the base) to the portion (lower side) that is adhesively held on the slice base S. If the imaging unit is configured to image this portion, the peeling operation can be started more reliably without the wafers coming into contact with each other, and the frequency of defects can be further reduced. The camera 123 is preferably disposed in a position where it can capture the above image, specifically, higher up, for example, in a position facing the slice base S with the wafer W in between, in other words, in a position where it can image the upper half of the wafer.

[0106] Next, a specific example of a method for measuring the gap from an image acquired by the camera 123 will be described. Returning to Fig. 9, the gap C between the first wafer W1 and the second wafer W2 appears black as shown in the figure. This is because light from a light source (not shown) is reflected by the circumferential surfaces of the wafers W1 and W2 and appears white, whereas no reflection occurs in the gap. Note that when an image is captured by transmitting light from the light source from the opposite side, the gap appears white and the circumferential surfaces of the wafers W1 and W2 appear black. Returning to FIG. 9, the width of the gap between wafers W1 and W2 can be obtained by measuring the width of the black portion (or the white portion if the image is taken through transmission) from the image.

[0107] After air is blown, it is confirmed by the camera 123 that the first and second sheets have been separated, and then the peeling operation for the first sheet is started. Air blowing is typically performed for a predetermined time before the operation of peeling off the first wafer. On this premise, if the width of the gap satisfies the above criteria as a result of imaging, it is preferable to configure so that air blowing is stopped even before the time has elapsed. Typically, the peeling unit starts the peeling operation after the air blowing is performed for a predetermined time (e.g., about several seconds). On this premise, if the width of the gap satisfies the above-mentioned criteria as a result of the imaging, it is preferable to be configured to start the peeling operation even before the time has elapsed.

[0108] With the above configuration, even within the predetermined time, the air blowing is stopped and the peeling operation is started, so that the blowing of air more than necessary can be suppressed. Even if the wafers W have already been separated, the operation of blowing air further is suppressed until the predetermined time is reached. In other words, since air is blown for a necessary and sufficient time, the time required for the peeling operation of one wafer can be shortened, and as a result, the processing capacity of the device (the number of wafers processed per hour) is improved.

[0109] If the imaging unit determines that the first and second sheets are not sufficiently separated (the gap width does not meet a predetermined standard) after the air is blown, the lifting of the first sheet may be stopped and the peeling operation may be performed again. Conventionally, air was blown for a predetermined time of about 3 seconds, and then the peeling operation was performed regardless of whether the sheets were actually separated or not. In contrast, in a configuration in which the lift is stopped according to the determination result by the imaging unit, the lift will not lift if the wafer W is not separated, and therefore there is no damage to the wafer W. In addition, since the peeling abnormality is checked before the peeling operation, the throughput can be improved and the productivity can be improved.

[0110] If the result of the determination by the imaging unit indicates that the width of the gap does not satisfy a predetermined standard, the temperature of the hot water 120 in the hot water tank may be adjusted by the temperature adjustment unit. A typical example of a case in which the first and second sheets come into contact with each other is a case in which there is a problem with the adhesive strength between the slice base S and the wafer W. For example, if the adhesive strength is too weak, the orientation of the wafer W cannot be maintained, the wafer W may tilt, and the parallelism between the wafers may be lost. In such a case, the temperature of the hot water 120 may be adjusted to maintain the adhesive strength. The specific temperature adjustment method depends on the properties of the adhesive, but for example, the temperature of the hot water may not be increased too much. When the temperature of the hot water 120 is adjusted, after the first wafer is peeled off, the width of the gap between the second wafer, which was the "third wafer", and the first wafer, which is the "first wafer", tends to meet the above criteria. As a result, the peeling operation is performed more quickly overall, and the processing capacity of the device is improved.

[0111] The imaging unit may acquire an image when the wafer W is lifted. Specifically, the image of the wafer W when passing through the slit SLT may be captured, and the occurrence of defects such as a linking state may be recorded as image information. From this image information, the occurrence of a problem can be detected using image recognition technology, and alert information can be generated. In addition, this image information can be used as a record of the process of separating individual wafers into single wafers. This image information can be used as basic information that contributes to improving the quality of the wafers to be separated into single wafers.

[0112] Furthermore, the defect detection by the imaging unit and the detection by the load detection unit may be used in combination. The imaging unit may not be able to obtain sufficient information to determine whether the wafers W are in contact with each other due to the influence of the posture of the wafers W and the influence of water vapor generated from the hot water 120. By using the imaging unit in combination with the load detection unit, it is easier to obtain sufficient information for a more accurate determination. For example, when two or more wafers W are transferred by the peeling unit 150, this can be detected by imaging, and also by the load detection unit from the load on the slit SLT of the single-wafer pickup adjustment unit 216. Also, when the wafer W is peeled off from the slice base S, the imaging unit confirms that there is no contact between the first and second wafers (the gap meets the criteria), and the load detection unit also confirms that there is no abnormality in the load during peeling. By providing the imaging unit and / or the load detection unit, the frequency of occurrence of defects can be further reduced, and occurrence of defects can be properly detected, thereby improving the quality of the wafers processed into single wafers.

[0113] (Another embodiment 1) Next, a wafer separating and cleaning apparatus according to another embodiment disclosed in this specification will be further described.

[0114] A 1A wafer peeling and cleaning apparatus disclosed in this specification peels off wafers cut from an ingot into a batch state from a slice base one by one to form single wafers, and cleans the peeled wafers one by one, and includes a peeling suction pad that suction-holds a surface on one side of the wafer, and at least one air supply unit configured to blow air along the surface of the wafer and from the slice base side toward the wafer side, wherein, when the wafer held by suction is a first wafer, the air supply unit blows the air between the first wafer and a second wafer adjacent to the first wafer, and between the wafers adjacent to the second wafer and thereafter, so that the air blown between the first wafer and the second wafer is stronger than the air blown between the wafers subsequent to the second wafer.

[0115] When the wafers, which are cut from an ingot and lined up one by one with one end (part of the circumferential surface) glued and held by a slice base, are peeled off one by one, the parallel wafers are lined up with their surfaces facing each other. The wafers are glued and held on the slice base in a nearly parallel state until peeling. However, if the wafers change position for some reason (for example, they tilt), they may come into contact with each other.

[0116] When the wafers come into contact with each other, water vapor or the like may get in the gap and cause them to stick to each other. In particular, the end faces opposite to the side held by the slice base are in a so-called free state, so even a slight tilt of the wafers can easily cause them to come into contact with each other, and contact is likely to occur.

[0117] If adjacent wafers come into contact with each other, this will cause problems when peeling them off one by one. For this reason, air has traditionally been blown between the wafers to separate them before peeling them off. Also, to improve the processing capacity per unit time of the peeling operation, air is sometimes simultaneously supplied not only between the first and second wafers, but also between the second and third wafers, the third and fourth wafers, and so on, so that preparations for peeling can be carried out simultaneously.

[0118] However, when air is blown strongly into the gaps between the wafers, the wafers may vibrate depending on the adhesive strength with the slice base. As a result, for example, when the second wafer is pushed by the vibration of the third or subsequent wafers, the first and second wafers may end up coming into contact with each other. In other words, it was difficult to sufficiently improve processing capacity by simply blowing air into the gaps between the wafers.

[0119] The 1A wafer peeling and cleaning apparatus disclosed in this specification is configured so that the air blown between the first and second wafers is stronger than the air blown between the second and subsequent wafers, so that the first and second wafers can be reliably separated even when air is blown between the second and subsequent wafers at the same time. Therefore, the peeling operation of the first wafer can be reliably performed, and further, air can be blown simultaneously on the second and subsequent wafers, improving the processing capacity (number of wafers) per hour.

[0120] The 2A wafer peeling and cleaning apparatus disclosed in this specification is the 1A wafer peeling and cleaning apparatus, in which the air supply section has at least one elongated air outlet in the thickness direction of the wafer.

[0121] The 2A wafer peeling and cleaning device has at least one elongated air outlet in the thickness direction of the wafer, so that it is easier to blow air between the first and second wafers and between the second and subsequent wafers at the same time. The air outlet may have a longitudinal direction substantially parallel to the direction in which the wafer faces. When the adhesive strength between the slice base and the wafer is adjusted, typically weakened, by the hot water in the hot water bath, the wafer may move from its intended position (the position where the first wafer should be held by suction, and the position where the second wafer and subsequent wafers should wait). The 2A wafer peeling and cleaning device is equipped with a slotted air outlet that is elongated in the direction in which the wafers are arranged, so that air can be blown to the desired position even if the wafer position is slightly shifted from the desired position.

[0122] A 3A wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus in which, in the 2A wafer peeling and cleaning apparatus, the at least one elongated air outlet includes a plurality of elongated air outlets.

[0123] The wafer cleaning device of 3A, for example, is provided with two long hole-shaped air outlets, one of which can be used mainly for blowing air between the first and second wafers, and the other can be used mainly for blowing air between the second and subsequent wafers. With this configuration, it becomes easier to adjust the strength of the air blown between the first and second wafers. In this case, it is preferable that each air outlet is connected to an independent compressor (which may include a regulator) or air piping, etc., and air is supplied at approximately the same pressure.

[0124] A 4A wafer peeling and cleaning apparatus disclosed in this specification is a 3A wafer peeling and cleaning apparatus in which at least two or more of the plurality of long hole-shaped air outlets have different longitudinal lengths and / or shorter lengths.

[0125] In the case where the 4A wafer peeling and cleaning apparatus has two long hole-shaped air outlets, the length in the longitudinal direction and / or the length (width) in the lateral direction are different from each other. Typically, one is a smaller air outlet and the other is a larger air outlet. Air outlets of different sizes will blow air with different strengths when supplied with the same air pressure, making it easier to blow air more strongly between the first and second sheets. For example, by using the smaller (stronger) nozzle mainly to blow air between the first and second wafers and the larger (weaker) nozzle mainly to blow air between the second and subsequent wafers, it is possible to easily adjust the strength of the air blown between the first and second wafers.

[0126] When the two air outlets are connected to separate compressors (separate systems) and air is supplied at the same pressure, the air outlet with a shorter length will blow out more air than the other air outlets. For this reason, this outlet is mainly suitable for blowing air between the first and second panels. On the other hand, if the two air outlets receive air supply from the same compressor or the like (by branching off the same piping, for example), the longer air outlet can sometimes be used mainly to blow air between the first and second panels.

[0127] The No. 4A wafer peeling and cleaning equipment has two long hole-shaped air outlets of different lengths, so the strength of the air blown from each air outlet can be easily adjusted and each air outlet can be easily assigned a different role. In other words, it is easy to realize a configuration that blows air more strongly between the first and second wafers with a simpler configuration.

[0128] The 5A wafer peeling and cleaning apparatus disclosed in this specification is a 2A wafer peeling and cleaning apparatus in which the at least one long hole-shaped air outlet is configured such that the length of its short side is shortened stepwise and / or continuously in the direction in which the wafer faces, from the first wafer to the second wafer.

[0129] The air outlet of the air supply unit of the wafer peeling and cleaning device of No. 5A has a short-side length (width) that gradually and / or continuously shortens in the direction from the first wafer to the second wafer, so that the strength of the air blown out from the outlet can be varied as desired by simply supplying compressed air from one system to one air outlet. In other words, if air is supplied at a predetermined pressure, the air is blown out strongly in the wide parts and weakly in the narrow parts. With a simple configuration in which the width is narrowed in the direction from the first wafer to the second wafer, it is possible to blow air strongly between the first and second wafers.

[0130] The 6A wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus in which, in the first wafer peeling and cleaning apparatus, the at least one air supply unit includes a plurality of the air supply units, and at least a pair of the air supply units among the plurality of air supply units are arranged opposite each other in a direction along the surface of the wafer, sandwiching the wafer therebetween.

[0131] The 6A wafer peeling and cleaning device includes, for example, two air supply units that are arranged to sandwich the wafer and face each other in a direction along the surface of the wafer. In other words, the two air supply units are arranged on both sides of the end surface (circumferential surface) of the wafer, so that air can be supplied evenly from both sides, and each wafer can be separated stably. It is preferable to blow air evenly from both sides of the wafer. By blowing air evenly, the wafers can be separated more reliably.

[0132] For example, when the air blown from the air supply units has substantially the same strength, it is preferable that the number of opposing air supply units is the same, i.e., it is preferable to provide a plurality of pairs of air supply units. Moreover, each air supply unit may include one air outlet, or may include two or more air outlets.

[0133] (Another embodiment 2) Next, a wafer separating and cleaning apparatus according to another embodiment disclosed in this specification will be further described.

[0134] The 1B wafer peeling and cleaning apparatus disclosed in this specification is a wafer peeling and cleaning apparatus that peels wafers cut from an ingot into a batch state one by one from a slice base to separate them into individual wafers and cleans the peeled wafers individually, and is equipped with a peeling unit including an arm that holds the wafer and peels it from the slice base, and an imaging unit that is positioned to image an area including a gap between the first wafer and a second wafer adjacent to the first wafer when the wafer held by the arm is a first wafer, and the peeling unit starts the peeling operation of the first wafer when the width of the gap satisfies a predetermined standard as a result of the imaging.

[0135] When the wafers, which are cut from an ingot and lined up one by one with one end (circumferential surface) glued and held by a slice base, are peeled off one by one, the parallel wafers are lined up with their surfaces facing each other, and water may get between them and cause the wafers to stick to each other. In particular, the end surface opposite the one held by the slice base is in a so-called free state, so even a slight tilt of the wafers can easily cause them to come into contact, easily causing sticking.

[0136] If adjacent wafers are stuck together, this becomes an obstacle when peeling them one by one, so conventionally, air is blown between the wafers to separate the stuck wafers and peel them off. Also, to improve the processing capacity per unit time of peeling, air is simultaneously supplied not only between the first and second wafers, but also between the second and third wafers, the third and fourth wafers, and so on, so that preparation for peeling can be carried out simultaneously.

[0137] However, even when air was blown, wafers would sometimes stick to each other. In this case, when the first wafer was peeled off or transferred, the second wafer would be pulled along and moved, which could be one of the causes of defects such as scratches and chips.

[0138] The 1B wafer peeling and cleaning device is configured to capture an image of an area including a gap between a first wafer to be peeled and a second wafer adjacent thereto by an imaging unit, and to start a peeling operation when the width of the gap satisfies a predetermined criterion. The predetermined criterion is, for example, a certain numerical range including the size (design value) of the gap between the wafers when the wafers maintain a desired posture (almost parallel). When this criterion is satisfied, it means that there is a sufficient gap between the first wafer and the second wafer. The imaging unit confirms that the first and second wafers are sufficiently separated, i.e., that they are not in contact with each other, before starting the peeling operation, thereby reducing the frequency of defects.

[0139] The 2B wafer peeling and cleaning apparatus disclosed in this specification is a 1B wafer peeling and cleaning apparatus that is equipped with a hot water tank configured to store hot water, immerse at least the slice base in the hot water, and adjust the adhesive strength of the adhesive that bonds the wafer and the slice base, wherein the wafer is held so as to protrude outward from the surface of the hot water with the slice base immersed in the hot water, and the imaging unit is positioned in a position where it can image the area in the protruding portion.

[0140] The second B wafer peeling and cleaning device includes a hot water bath. The slice base side of the wafer is immersed in hot water stored in the hot water bath, and the opposite end (the majority of the wafer) is held so as to protrude above the water surface, adjusting (typically softening) the adhesive strength of the adhesive, so that the wafer can be more easily peeled off from the slice base. The imaging unit is configured to image the area of ​​the wafer that protrudes above the water surface when the wafer is adhesively held on the slice base in a predetermined posture. Contact between the wafers is likely to occur in the area protruding above the water surface because the wafers are adhesively held at a predetermined distance from each other on the slice base. According to the second wafer peeling and cleaning device in which the imaging unit is configured to image this area, the peeling operation can be started more reliably without the wafers contacting each other, and the frequency of defects can be further reduced.

[0141] The 3B wafer peeling and cleaning apparatus disclosed in this specification is a 1B or 2B wafer peeling and cleaning apparatus, in which the imaging unit is positioned at a position capable of imaging the area including the portion of the wafer held by the slice base and the circumferential surface of the wafer at a position approximately symmetrical about the center thereof.

[0142] Wafers are more likely to come into contact with each other at the portion (upper side) that is symmetrical (with respect to) the center of the wafer with respect to the portion (lower side) that is adhesively held on the slice base. This is because there is nothing (slice base) to support the wafer in that portion. By using the imaging unit to image the gap portion including the circumferential surface of the wafer in this portion and starting the peeling operation after confirming the gap, the peeling operation can be started more reliably without the wafers being stuck to each other, which can further reduce the frequency of defects.

[0143] The 4B wafer peeling and cleaning apparatus disclosed in this specification is a 2B or 3B wafer peeling and cleaning apparatus that includes at least one air supply unit configured to blow air along the surface of the wafer extending from the slice base and from the slice base side toward the wafer side, and the imaging unit images the area when the air is blown.

[0144] According to the 4B wafer peeling and cleaning device, the air supply unit supplies air from the bottom to the top of the wafer, so that even if the first and second wafers are in contact with each other, they can be separated. By capturing an image of the gap while air is being blown, the peeling operation can be started more reliably without the wafers touching each other, so the frequency of defects can be further reduced.

[0145] A 5B wafer peeling and cleaning apparatus disclosed in this specification is a 4B wafer peeling and cleaning apparatus, wherein the air supply unit is configured to blow the air for a predetermined time before the peeling operation of the first wafer, and if the width of the gap satisfies the criterion as a result of the imaging, the blowing of the air is stopped even before the time has elapsed.

[0146] The 5B wafer peeling and cleaning device is configured to stop blowing air when it is confirmed that no contact has occurred as a result of imaging, even if it is within a predetermined time, so that it is possible to prevent the blowing of more air than necessary. In other words, because only a necessary and sufficient amount of air is blown, the time required for the peeling operation of one wafer can be shortened, and the processing capacity of the device (the number of wafers processed per hour) is improved.

[0147] The 6B wafer peeling and cleaning apparatus disclosed in this specification is a 1B wafer peeling and cleaning apparatus that is equipped with a hot water tank configured to store hot water, immerse at least the slice base in the hot water, and adjust the adhesive strength of the adhesive that bonds the wafer and the slice base, and a temperature control unit that adjusts the temperature of the hot water, and if the width of the gap does not satisfy a predetermined standard as a result of the imaging, the temperature control unit adjusts the temperature.

[0148] According to the 6B wafer peeling and cleaning device, if the width of the gap does not meet a predetermined standard, the temperature of the hot water is adjusted accordingly. A case where the predetermined standard is not met, that is, contact occurs, can be, for example, a case where there is a problem with the adhesive strength between the slice base and the wafer. For example, if the adhesive strength is too weak, the wafer cannot maintain its position, and the parallelism between the wafers may be lost. In such a case, the temperature is adjusted to maintain the adhesive strength. The specific temperature adjustment method depends on the properties of the adhesive, but for example, the temperature of the hot water is lowered or not raised too high. By adjusting the water temperature, the gap width is more likely to meet the above criteria when the first wafer is peeled and the second and subsequent wafers are peeled in sequence. As a result, the overall peeling operation is performed more quickly, and the processing capacity of the equipment is improved.

[0149] The 7B wafer peeling and cleaning apparatus disclosed in this specification is a 1B wafer peeling and cleaning apparatus that is equipped with a single-piece adjustment unit including a slit whose width is adjusted to allow the wafers transferred by the peeling unit to pass through one by one after being peeled, and the imaging unit images the wafer as it is peeled off from the slice base, transferred while held by the arm, and passes through the slit.

[0150] The 7B wafer peeling and cleaning device is equipped with a single-piece adjustment unit, so that it can more reliably obtain "one" wafer. The single-piece adjustment unit functions, for example, when a part of a first wafer is touched by a second wafer waiting to be peeled during peeling or transportation, causing the surfaces to adhere to each other through water, resulting in a "linking state" in which the second wafer is also pulled and transported. In this case, the second wafer cannot pass through the slit of the single-piece adjustment unit, so only the first wafer is obtained.

[0151] However, at this time, the second wafer comes into contact with the single-piece adjustment unit and is released from its tight contact, which may cause defects such as cracks and chips to occur along with the first wafer (especially the second wafer). On the other hand, even if a linking state occurs, the wafer may pass through the slit plate of the single-piece adjustment unit. This may result in a wafer with a risk of cracks, chips, or other defects being moved to the next process.

[0152] In the 7B wafer peeling and cleaning device, the imaging unit captures images of the wafer as it passes through the slit, so that the occurrence of defects such as linking can be recorded as image information. This image information can be used, for example, to detect the occurrence of a problem by image recognition and generate alert information, or to record the history of each wafer. In other words, it can be used as basic information that contributes to improving the quality of the wafers manufactured. [Explanation of symbols]

[0153] 1. Wafer peeling and cleaning equipment 10 Rough cleaning section 12 Rough cleaning equipment 80, 81 Air nozzle 81-1, 81-2, 81-3 Nozzle holes 100 Wafer peeling section 112 Hot water tank 114 Peeling device 118 Delivery Device 120 Hot water 123 Camera 150 Peeling Unit 190 Arm 200 First peeling suction pad 201 Second peeling suction pad 216 Single-piece adjustment section 310 Conveyor 350 Single wafer cleaning section 352 Brush Cleaning Section 354 Pre-rinse section 356 Rinse Department 400 Detector 500 Collection Department

Claims

1. In a wafer peeling and cleaning apparatus that peels wafers, which have been cut from an ingot and are in a batch state, from a slice base one by one to form single sheets, and then cleans the peeled wafers, A peeling unit including an arm that holds the wafer and peels it from the slice base, The system includes a load detection unit that detects the load on the arm, The load detection unit detects at least the load during the peeling of the wafer from the slice base, in a wafer peeling and cleaning apparatus.

2. After the wafers have been peeled, the system includes a single-wafer adjustment section with a slit whose width has been adjusted to allow the wafers to pass through one by one as they are transported by the peeling unit. The wafer peeling and cleaning apparatus according to claim 1, wherein the load detection unit detects the load when the wafer, peeled from the slice base, is transported while being held by the arm and passes through the slit.

3. The peeling unit is configured to be able to transport the wafer held by the arm at a predetermined speed, The wafer peeling and cleaning apparatus according to claim 2, wherein the load detection unit determines whether the detected load is from the peeling process or from the passage through the slit, based on the current position of the wafer calculated based on the time since the start of the peeling by the peeling unit.

4. A hot water bath is configured to store hot water, immerse at least the slice base in the hot water, and adjust the adhesive strength of the adhesive bonding the wafer and the slice base. The system includes a temperature control unit that adjusts the temperature of the hot water, The wafer peeling and cleaning apparatus according to any one of claims 1 to 3, wherein the temperature control unit adjusts the temperature of the hot water based on the magnitude of the load during peeling.

5. A hot water bath is configured to store hot water, immerse at least the slice base in the hot water, and adjust the adhesive strength of the adhesive bonding the wafer and the slice base. The system includes a temperature control unit that adjusts the temperature of the hot water, A wafer peeling and cleaning apparatus according to any one of claims 1 to 3, wherein the criteria for determining the magnitude of the load during peeling are predetermined in at least two stages, and depending on the stage to which the magnitude of the load belongs, the temperature of the hot water is adjusted by the temperature control unit, the peeling operation is performed again, or the peeling operation is stopped and first alert information is generated.

6. The wafer peeling and cleaning apparatus according to claim 2 or 3, which generates a second alert information based on the magnitude of the load when passing through the slit.

Images