JP2007311658A - Semiconductor wafer reproduction system, and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silicon wafer reproduction system which can easily, efficiently remove and reproduce a pattern of a silicon wafer, and to provide its method. <P>SOLUTION: The reproduction system includes a grid blaster ejecting a grid onto the surface of the silicon wafer, a catching means which catches a chip produced from the silicon wafer, the grid, and a powder containing dust produced from the silicon wafer and grid, a cyclone separating means which is connected to the catching means, separate the dust from the chip and grid supplied from the catching means and discharge, and resupplies the chip and grid separated from the dust to the grid blaster, a dust collecting means which is connected to the cyclone separating means and collects the dust discharged from the cyclone separating means, and destacker which is located to be able to continuously load the silicon wafer upstream of a mesh conveyer one by one. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor wafer regeneration system and method, and more particularly, to a semiconductor wafer regeneration system and method for reclaiming a silicon wafer by removing a defective pattern of the semiconductor wafer.

  In consideration of the fact that the unit processes are highly sophisticated and serialized in the semiconductor manufacturing process, it is generally verified whether the wafer is in good condition or not damaged in the past. A wafer test is performed during the unit period. If the number of dies determined to be damaged among the dies on the wafer exceeds the reference value, the wafer is not thrown into the subsequent process and discarded. On the other hand, after the metal wiring process is completed, a device test is performed to test whether or not the semiconductor elements normally operate. If the yield indicating the percentage of normally operating elements is high enough, the wafer is packaged after being cut and attached to a lead plate. However, wafers with yields below the reference value are discarded.

  Wafers that fail to pass the wafer test or device test and are discarded retain the circuit pattern, and therefore cannot be used for other purposes, and are generally crushed and embedded. Treating discarded wafers in this way not only results in wasting expensive resources, but can also cause environmental contamination. Therefore, there is a strong demand for a method that can recycle discarded wafers.

  There have been proposals to recycle discarded wafers. For example, US Pat. No. 6,706,636 discloses a method for regenerating a semiconductor wafer using a mixed acid. According to this method, the wafer is polished and then immersed in the mixed acid. Thereafter, the wafer is surface-treated to be flattened, and heat-treated at a high temperature to finally obtain a regenerated wafer. However, since this method includes a large number of steps, it can be said that it takes a lot of time for regeneration and is inefficient. Furthermore, simply polishing the wafer and immersing it in a mixed acid makes it difficult to completely remove ion-implanted regions and trenches deeply formed on the surface that have different physical properties from pure silicone. In addition, since many kinds of acids are used, the cost of reclaiming the wafer can be increased.

  US 2005/0092349 discloses a method of reclaiming a semiconductor wafer by a series of processes, namely etching, polishing and heat treatment. Among many processes, this method focuses on heat treating the wafer for 20 minutes to 5 hours. Therefore, this method is more time consuming and inefficient.

  As described above, the conventional method has a problem that productivity is low and a large amount of chemicals and abrasives are used, resulting in a large increase in cost. Therefore, the conventional wafer recycling method has a problem that there is almost no profit in the economical aspect.

  The present invention has been devised to solve the above-described problems, and provides a semiconductor wafer recycling system that can easily and efficiently remove and reproduce a semiconductor wafer pattern. There is that purpose.

  It is another object of the present invention to provide a method for reclaiming a semiconductor wafer that can remove the pattern of the semiconductor wafer easily and efficiently and regenerate it.

  In order to achieve the above object, the semiconductor wafer recycling system of the present invention removes the pattern of the semiconductor wafer in a dry manner by spraying grit onto the surface of the semiconductor wafer.

  The semiconductor wafer recycling system is installed above the mesh conveyor for transferring the semiconductor wafer with the semiconductor wafer pattern facing upward, and the semiconductor wafer so that the pattern of the semiconductor wafer is removed. A grit blaster comprising one or more projection nozzles for injecting grit onto the surface of the wafer, a swing means for swinging the projection nozzle so as to intersect a transfer direction of the semiconductor wafer transferred by the mesh conveyor, and the mesh Installed below the conveyor, connected to the collection means for collecting the grit falling from the mesh conveyor, chips, and powder containing dust, and to the collection means, from the collection means The grit from the supplied powder and the A cyclone separator means for separating-up and dust, are connected to said separation means, and a dust collection unit for dust collection of the dust discharged from the separating means.

  Grips sprayed onto the surface of the semiconductor wafer can be separated by the separating means and recycled. In such a case, the cost of the entire process can be saved. Thus, a cyclone separator can be used in the separation means for separating the grit and the chip.

  The operation of loading the semiconductor wafer onto the mesh conveyor can be automatically performed by a duteco.

  On the other hand, the method for reclaiming a semiconductor wafer of the present invention to achieve the other object includes a step of removing moisture from a semiconductor wafer having a pattern by baking, and a pattern of the semiconductor wafer facing upward by a mesh conveyor. Transferring the wafer; spraying grit onto the surface of the semiconductor wafer by a grit blaster to remove the pattern; grit falling from the mesh conveyor; chips; and powder containing dust, the mesh conveyor. Collecting the grit and the chip from the dust, resupplying the grit and the chip to the grit blaster, and collecting the separated dust. Including stages.

  As described above, according to the semiconductor wafer recycling system and method according to the present invention, it is possible to easily and efficiently remove the defective pattern of the semiconductor wafer. Semiconductor wafers reclaimed according to the present invention can be used in the manufacture of applications that require lower levels of flatness and purity than integrated circuits, such as solar cells. Further, according to the present invention, chips and dust can be easily processed by removing the pattern of the semiconductor wafer by grit blasting, and the used grit and chips can be reused for grit blasting. Thus, the cost can be reduced and the yield can be greatly improved by automatically supplying the semiconductor wafer.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  First, referring to FIGS. 1 and 2, a semiconductor wafer regeneration system (hereinafter referred to as a regeneration system) according to the present invention includes a frame 10. A mesh conveyor 20 for transferring the silicon wafer 1 is installed on the frame 10. In addition, a blasting booth 60 surrounding the upper and side surfaces of the mesh conveyor 20 is installed at the upper part of the frame 10, and a cleaning booth 65 is installed downstream of the blasting booth 60. Inside the blast booth 60, a grit blaster for injecting grit G for removing the pattern 2 onto the surface of the silicon wafer 1 transferred above the mesh conveyor 20 is installed. On the other hand, a cleaning nozzle that removes impurities remaining on the surface of the wafer 1 with compressed air is installed inside the cleaning booth 65.

  On the other hand, the grid conveyor 20 has a grit that bypasses the silicon wafer without colliding with it, a grit that collides with the wafer and flies away by removing the pattern, a grit break that is generated by the collision with the wafer, and a wafer that falls off. A collecting device 90 is installed to collect the insulation and metal wiring pattern breakage and the powder from which the wafer and grit are broken. In this specification, including the claims, the term “grit G” refers to the grit that is initially charged, the grit that bypasses the wafer without colliding, the grit that collides with the wafer and removes the pattern, and flies. It is used to generically refer to a grit break generated by collision with a wafer. The term “chip C” is used to collectively refer to an insulator or a metal wiring pattern that falls off on a wafer. Further, the term “dust D” is used to express a powder in which a wafer or grit is broken. The term “powder P” is used to represent an aggregate of grit G, chips C, and dust D falling from the mesh conveyor 20.

  A cyclone separator (Cyclone separator) 100 is connected to the collection device 90, and the grit G, the chip C, and the dust D from the powder P discharged through the second powder pipeline 93 of the collection device 90. Are separated by centrifugal force. A dust collector (Dust collector) 110 collects the dust D discharged from the cyclone separator 100.

Referring to FIG. 3, the mesh conveyor 20 includes a driving pulley 21, a driven pulley 22, a mesh belt 23, and a motor 24. The driving pulley 21 and the driven pulley 22 are attached separately along the transfer direction of the silicon wafer 1, and the mesh belt 23 is wound between the driving pulley 21 and the driven pulley 22. On the mesh belt 23, the silicon wafer 1 is transferred with the silicon wafer pattern 2 facing upward. The mesh belt 23 can be made from stainless steel wire and the mesh can be about 2 mm ² . The motor 24 is attached to one side of the frame 20, and the driving force is transmitted to the driving pulley 21 by the belt transmission device 25. The motor 24 may be configured by a geared motor that can directly transmit the driving force to the driving pulley 21 by decelerating.

  The blast booth 60 has a first tunnel 61 through which the mesh conveyor 20 passes. As shown in FIG. 1, a door 62 that can open and close the first tunnel 61 is attached to the front surface of the blast booth 60 for maintenance of the nozzle 31. The door 62 is provided with a window 63 that allows an operator to check the inside of the first tunnel 61 with the naked eye. Similar to the blast booth 60, the cleaning booth 65 has a second tunnel 66 so that the mesh conveyor 20 passes and the downstream side is exposed. The first tunnel 61 of the blast booth 60 and the second tunnel 66 of the cleaning booth 65 are connected to be aligned. A door 67 capable of opening and closing the second tunnel 66 is attached to the front surface of the cleaning booth 65 for maintenance of the cleaning nozzle 32, and an operator can visually confirm the second tunnel 66 with the naked eye. A window 68 capable of checking the inside is provided.

  The upstream side of the mesh conveyor 20 is exposed outside the blast booth 60 so that the silicon wafer 1 can be loaded on the inlet side of the blast booth 60. Further, on the outlet side of the cleaning booth 65, the downstream of the mesh conveyor 20 is exposed outside the blast booth 60 so that the silicon wafer 1 can be unloaded. In this embodiment, the cleaning booth 65 is formed separately from the blast booth 60. However, in another embodiment, the cleaning nozzle 32 is mounted downstream of the first tunnel 61 of the blast booth 60, and the grit blaster 30 and the cleaning booth 65 are cleaned. By providing a partition for partitioning the inside of the first tunnel 61 with the nozzle 32, the cleaning booth 65 can be eliminated.

  The grit blaster 30 includes a plurality of nozzles 31, a compressed air supply device 40, and a grit supply device 50. The nozzle 31 is attached along the longitudinal direction of the mesh conveyor 20 so that the compressed air and the grit G can be sprayed onto the surface of the silicon wafer 1 transferred on the mesh belt 23 of the mesh conveyor 20.

  Referring to FIG. 6, the compressed air supply device 40 includes an air compressor 41, a reservoir (storage tank) 42, an air dryer 43, and a plurality of air pipelines 44. The air compressor 41 is attached close to one side of the frame 10. The air compressor 41 is connected to a reserve 42, and the reserve 42 is connected to an air dryer 43. The compressed air generated by driving the air compressor 41 is stored in the reserve 42, and the compressed air of the reserve 42 is supplied to the air dryer 43. The air dryer 43 removes impurities such as water, oil, and dust contained in the compressed air supplied from the reserve 42 and controls the flow rate of the compressed air. The air dryer 43 can be composed of an air control unit that removes impurities contained in the compressed air from the reserve 42 and simultaneously controls the flow rate. The air dryer 43 is connected to each nozzle 31 by an air pipeline 44, and the compressed air supplied from the air dryer 43 is jetted onto the surface of the silicon wafer 1 through the nozzle 31.

  Although one cleaning nozzle 32 is illustrated as being attached, the number of cleaning nozzles 32 can be increased as necessary.

  Referring to FIG. 7, the grit supply device 50 includes a tank 51 that stores a large amount of grit G, and a plurality of nozzles 31 and the tank 51 that connect the grit G stored in the tank 51 to the nozzle 31. And the grit pipeline 52. The grit G can be used in various ways such as particles such as aluminum oxide, silicon carbide, ceramic, glass beads, steel balls, and chips that fall off the silicon wafer 1. Aluminum oxide, silicon carbide and ceramic particles having a particle size of 10 to 80 μm can be used, for example.

  4 and 5, the regeneration system according to the present invention includes a swing device 70 that swings the nozzle 31 so as to intersect the transfer direction of the silicon wafer 1. The swing device 70 includes a spindle 71, a motor 72, and a link device 80. The spindle 71 is attached in parallel along the transfer direction of the silicon wafer 1, and both ends of the spindle 71 are supported by a pair of bearings 73. The bearings 73 are fixed to both side surfaces of the blast booth 60, and one end of the spindle 71 protrudes through the blast booth 60. A plurality of support bars 74 are connected to the outer surface of the spindle 71 at a predetermined distance along the transfer direction of the silicon wafer 1, and the nozzles 31 are fixed to the lower ends of the support bars 74. The motor 72 is attached to one side of the outer surface of the blast booth 60.

  The link device 80 converts the rotational force of the motor 72 so that the spindle 71 is swung and transmits it to the spindle 71, and is composed of a disk 81, a first link 83, and a second link 84. The disk 81 is mounted on the shaft 72a of the motor 72, and a guide rail 82 is formed on the front surface along the radial direction. One end of the first link 83 is fixed to the disk 81 so as to be swingable by fastening a screw 85, and the screw 85 is coupled so as to be movable along the guide rail 81. One end of the second link 84 is connected to the other end of the first link 83 so as to be rotatable around the pivot 86, and the other end of the second link 84 is rotatably connected to one end of the spindle 71. .

  When the driving force of the motor 72 is transmitted to the spindle 71 by the disk 81, the first link 83, and the second link 84 of the link device 80, the spindle 71 is swung. The grit G ejected through the nozzle 31 by the swing of the spindle 71 reaches the entire surface from the center to the edge of the silicon wafer 1. 4 and 5, it is shown that the nozzles 31 are mounted in two rows along the transfer direction of the silicon wafer 1 and are swung by the operation of the swing device 70. This is exemplary, and the nozzles 31 may be mounted in a row as necessary. Further, the nozzle 31 may be installed so as to be able to reciprocate linearly along a direction intersecting the transfer direction of the silicon wafer 1. On the other hand, when the operator unscrews the first link 83 and moves the first link 83 along the guide rail 82, one end of the first link 83 is located between the center of the disk 81 and the edge of the disk 81. Located between. The swing angle of the spindle 71 increases as one end of the first link 83 is located at the edge away from the center of the disk 81.

  As shown in FIG. 3, the collection device 90 includes a plurality of hoppers 91, a first powder pipeline 92, and a second powder pipeline 93. The inlet 91 a of the hopper 91 is close to the lower part of the mesh conveyor 20, and the first powder pipeline 92 is connected to the outlet 91 b of the hopper 91. A second powder pipeline 93 is connected to one side of the first powder pipeline 92 so as to transport the powder P to the outside. A first screen filter 94 capable of filtering debris B generated by breakage of the silicon wafer 1 is attached to the upper portion of the hopper 91. A second screen filter 95 capable of filtering chips C having a particle size larger than that of the grit G is attached upstream of the second powder pipeline 93 adjacent to the first powder pipeline 92.

  Referring to FIG. 7, the housing 101 of the cyclone separator 100 is upright and has a chamber 102. An inlet 103 connected to the second powder pipeline 93 is formed at the upper part of the housing 100, and an outlet 104 from which the chips C and grit G are discharged is formed at the lower part of the housing 100. An outlet pipe 105 is connected to the center of the upper surface of the housing 101 so that the dust D can be discharged from the chamber 102. The outlet 104 of the housing 101 is connected to the tank 51 of the grit supply device 50 by a grit return pipeline 53. FIGS. 1 and 2 show that the housing 101 of the cyclone separator 100 and the tank 51 of the grit supply device 50 are installed at the upper part of the blast booth 60. The tank 51 of the grit supply device 50 may be installed separately from the blast booth 60.

  Referring to FIG. 8, the housing 111 of the dust collector 110 is upright and has a chamber 112. An inlet 113 is formed at the lower part of the housing 111, and an outlet 114 is formed at the upper part of the housing 111. The inlet 113 of the housing 111 is connected to the outlet 104 of the cyclone separator 110 by a dust pipeline 115. A partition 116 that partitions the chamber 112 is attached to the upper portion of the chamber 112, and the partition 116 is provided with a plurality of holes 116 a that form air flow paths. A plurality of filters 118 for filtering the dust D are attached to the holes 116 a of the partition 116. A hopper 118 for guiding the discharge of the dust D is attached to the lower part of the housing 111.

  An air blower 119 that generates air suction is installed at the outlet 114 of the housing 111 so that the air filtered by the filter 118 is discharged through the outlet 114. The air blower 119 can be composed of a vacuum pump. A dust box 120 capable of collecting the dust D discharged through the outlet 114 is attached to the lower portion of the housing 111. A first door 121 that can open and close the chamber 112 for maintenance of the filter 118 is attached to the outer surface of the housing 111, and the lower portion of the outer surface of the housing 111 is opened and closed to pull out the dust box 120. A second door 122 is attached which is capable of doing so.

  The dust collector 110 is illustrated and described as an upward air flow type in which an air flow is generated from the lower inlet 113 to the upper outlet 114. However, the dust collector 110 is a downward air flow type in which the positions of the inlet 113 and the outlet 114 are reversed. It may be configured. Further, the dust collector 110 is illustrated and described as a dry type dust collector that filters the dust D by the filter 118, but is configured by a known wet type dust collector or an electric dust collector as necessary. May be.

  The dust collector 110 includes an air blaster 130 that injects compressed air so that the dust D adhering to the filter 118 can be removed. The air blaster 130 includes an air compressor 131 that generates compressed air, and a plurality of nozzles 133 that are connected by the air compressor 131 and the air pipeline 132 and inject the compressed air supplied from the air compressor 131 onto the filter 118. Has been. The nozzle 133 can be connected to the air dryer 43 of the compressed air supply device 40 by an air pipeline 132. In this case, the air compressor 131 is deleted. The air blaster 130 can be constructed of a known vibration generator capable of generating vibrations in the filter 118 and dropping the dust D.

  Referring to FIG. 9, the motor 24 of the mesh conveyor 20, the air compressor 41 and the air dryer 43 of the compressed air supply device 40, the motor 72 of the swing device 70, the air blower 119 of the dust collector 110, and the air compressor 131 of the air blaster 130. Is controlled by the controller 140. The controller 140 is attached to one side of the blast booth 60.

  In the semiconductor wafer recycling system of the present invention, silicon wafers are preferably loaded on the mesh conveyor 20 one by one continuously. 10 to 14 are diagrams showing an embodiment of a destacker that is installed upstream of the mesh conveyor 20 and loads the silicon wafers 1 on the mesh belt 23 one by one continuously. The destacker 200 includes a frame 210, a stacker 220, a lift device 230, a feeder 240, a vacuum suction unit 250, an air blaster 260, a compressed air supply device 270, and a controller 280. The frame 210 includes a base 211 and first and second side frames 212 and 213 attached to both sides of the base 211.

  As shown in FIGS. 10 to 13, the stacker 220 is mounted at the center of the base 211 so that a large number of silicon wafers 1 can be stacked and accommodated. The stacker 220 has a plurality of supports standing up so as to form a stacking space 221 in which a large number of silicon wafers 1 can be stacked and accommodated above the base 211. As can be seen from FIG. 13, the support bars 222 are arranged along the circumferential direction rearward with respect to the horizontal center shaft ship 223 of the loading space 221 so that the silicon wafer 1 can be loaded from the front of the loading space 332. ing. An upper fixing plate 224, a lower fixing plate 225, and an intermediate fixing plate 226 are fixed to the upper end, lower end, and center of the support bar 222, respectively. The lower fixing plate 225 and the intermediate fixing plate 226 have mechanical rigidity of the stacker 220. Both ends of a plurality of reinforcing bars 227 for reinforcement are fixed.

  With further reference to FIGS. 10 to 13, a table 228 on which the silicon wafer 1 is placed is attached to the upper part of the intermediate fixing plate 226 so as to move up and down along the support bar 222. Each of the upper fixing plate 224 and the table 228 is provided with a plurality of positioning holes 224a and 228a, and the positioning holes 224a and 228a support the outer surface of the silicon wafer 1 having different diameters according to the size. A plurality of positioning bars 229 are respectively inserted so as to be able to. The support bar 222 can support the outer surface of the silicon wafer 1 having a diameter of 300 mm. Depending on the positioning bar 229, the outer surface of the silicon wafer 1 having a diameter of 100 mm, 125 mm, 150 mm, and 200 mm can be supported by adjusting the position thereof.

  Further, the lift device 230 raises the uppermost wafer 1-1 of the silicon wafers 1 loaded in the stacking space 221 of the stacker 220 so as to come to the standby position P1. The lift device 230 includes a first air cylinder 231 and a first linear motion guide 233. The cylinder housing 231a of the first air cylinder 231 stands vertically to the center of the stacker 220, and the lower end of the cylinder housing 231a is swingably coupled to the upper surface of the base 211. A cylinder load 231b of the first air cylinder 231 is slidably coupled to the lower surface of the table 228. The first linear motion guide 233 guides the vertical movement of the table 228 to linear reciprocation. The first linear motion guide 233 has a pair of guide rails 233a that are vertically attached to the inner surfaces of the first and second side frames 212 and 213, and is slid along the guide rails 233a. And a pair of slides 233b, and a joint 233c fixed to one end of the slide 233b and the table 228.

  The lift device 230 is attached so that it can be screwed along the lead screw, a servo motor that provides a driving force, a lead screw that is connected to the servo motor so that it can be rotated by the driving force of the servo motor, and the like. The ball bush connected to the table 228 and the linear motion guide for guiding the elevation of the table 228 to linear reciprocating motion can be used. The first linear motion guide 233 includes a pair of guide bars that are vertically attached to one side of the frame 210 and a pair of guide bars that are slidably attached to the guide bars and that are coupled to the table 228. The guide bush can be configured.

  The feeder 240 unloads the uppermost silicon wafer 1-1 among the silicon wafers 1 stacked in the stacking space 221 of the stacker 220 and loads it upstream of the mesh conveyor 20. The feeder 240 includes an arm 241, a second air cylinder 242, a carriage 243, and a second linear motion guide 244.

  The arm 241 is horizontally attached to one of the first and second side frames 212 and 213, for example, the upper part of the second side frame 213. The cylinder housing 242 a of the second air cylinder 242 is horizontally attached to the upper portion of the arm 241, and the rear end of the cylinder housing 242 a is swingably coupled to the upper surface of the arm 241. A cylinder load 242b of the second air cylinder 242 is slidably coupled to one side of the carriage 243. The second linear motion guide 244 guides the linear reciprocation of the carriage 243 along the arm 241. The second linear motion guide 244 includes a guide rail 244a attached to the upper surface of the arm 241 and a slide 244b attached to be slid along the guide rail 244a and coupled to the carriage 243. It is configured. The second air cylinder 242 of the feeder 240 can be constituted by a servo motor, a lead screw, and a ball bush capable of linearly reciprocating the carriage 243 along the arm 241.

  As shown in FIGS. 11 and 12, the vacuum pad 251 of the vacuum suction unit 250 is attached to one side of the lower surface of the carriage 243. The vacuum pad 251 is connected to a vacuum pump 252 that generates air suction and an air pipeline 253. When the first air cylinder 231 of the lift device 230 is driven to advance the cylinder load 231b, the uppermost silicon wafer 1-1 approaches the vacuum pad 251 at the standby position P1. When air suction is generated by driving the vacuum pump 252, the uppermost silicon wafer 1-1 is vacuum-sucked by the vacuum pad 251.

  As shown in FIG. 11, the air blaster 260 is configured so that the uppermost silicon wafer 1-1 of the silicon wafers 1 stacked in the stacking space 221 of the stacker 220 is separated from the second silicon wafer 1-2. Compressed air is injected into The air blaster 260 includes a plurality of nozzles 261 attached to one of the first and second side frames 212 and 213, for example, one side of the first side frame 212 along the vertical direction.

  Referring to FIG. 14, the compressed air supply device 270 is installed on one side of the first side frame 212 and supplies compressed air to the first air cylinder 231, the second air cylinder 242, and the nozzle 261 of the air blaster 260. . The compressed air supply device 270 can be composed of an air compressor, an air controller, and an air pipeline. Further, instead of the compressed air supply device 270 of the destacker 200, the compressed air supply device 40 of the grit blaster 30 can be applied. In this case, the air dryer 43 of the compressed air supply device 40 is connected to each of the first air cylinder 231, the second air cylinder 242, and the nozzle 261 of the destacker 200 via an air pipeline. The controller 280 is installed on the upper part of the first side frame 212 and controls the operation of the vacuum pump 252 and the compressed air supply device 270.

  The regeneration system according to the present invention may include a baking device for removing moisture and a protective film from the silicon wafer. FIG. 15 shows an embodiment of such a baking apparatus. The baking apparatus 300 includes an oven 310, a conveyor 320, and a heater 330. The oven 310 has a drying chamber 311, and an inlet 312 and an outlet 313 connected to the drying chamber 311 are formed on both sides of the oven 310. The conveyor 320 is installed such that its upstream and downstream are exposed to the outside through the inlet 312 and the outlet 313 of the oven 310. The heater 330 is installed in the upper part of the drying chamber 311 and heats the silicon wafer 1 that is transferred on the belt 321 of the conveyor 320. The heater 330 can be installed under the belt 321 so that the silicon wafer 1 can be dried by a fall method. The baking apparatus 300 may be installed upstream of the mesh conveyor 20 or the destacker 200, or may be installed independently of the mesh conveyor 20 or the destacker 200. Moreover, the conveyor 320 of the baking apparatus 300 may be installed so as to be continuous with the mesh conveyor 20. The oven 310 of the baking apparatus 300 may be a batch type. In this case, the conveyor 320 is deleted.

  Next, a silicon wafer regeneration method for reclaiming a silicon wafer by the regeneration system according to the present invention having such a configuration will be described with reference to FIG.

  Referring to FIG. 15 together, if the silicon wafer 1 discharged from the semiconductor manufacturing process has moisture such as chemicals or water, the silicon wafer 1 absorbs moisture during storage and is hydrophilic. Will have. When moisture remains on the surface of the silicon wafer 1 or is absorbed, the grit G ejected from the nozzle 31 sticks to the surface of the silicon wafer 1 or the impact force of the grit G that the silicon wafer 1 hits the surface. Therefore, the removal efficiency of the pattern 2 is lowered. Further, the protective film 3 covered with the pattern 2 by the protective film process in order to protect the pattern 2 of the silicon wafer 1 has a buffering force against the impact force of the grit G.

  The operator removes moisture and the protective film 3 from the silicon wafer 1 by operating the baking apparatus 300 (S10). An operator places the silicon wafer 1 on the belt 321 of the conveyor 320. At this time, a large number of silicon wafers 1 can be stacked and mounted on the belt 321 of the conveyor 320. The silicon wafer 1 is supplied to the drying chamber 311 through the inlet 312 of the oven 310 by the operation of the conveyor 320. The heat generated by the operation of the heater 330 is removed by evaporating water from the silicon wafer 1. Further, the protective film 3 of the silicon wafer 1 is removed, for example, by baking at a temperature of about 700 to 800 ° C. for about 20 to 30 minutes. The silicon wafer 1 from which moisture or a protective film has been removed is discharged from the drying chamber 311 through the outlet 313 of the oven 310 by the operation of the conveyor 320. Thus, if the water and the protective film 3 of the silicon wafer 1 are removed by a baking process to make the surface of the silicon wafer 1 hydrophobic, the efficiency of grit blasting is increased.

  Referring to FIGS. 1, 2, and 10 to 13, the worker loads a large amount of silicon wafers 1 with the pattern 2 facing upward in the loading space 221 of the stacker 220 (S 11). When the operator performs the stacking operation of the silicon wafer 1 after the positioning bar 229 is coupled to the positioning holes 224a and 228a of the upper fixing plate 224 and the table 228 according to the size of the silicon wafer 1, The outer surface is supported by the positioning bar 229 and aligned. A silicon wafer having a diameter of 300 mm can be aligned by removing the positioning bar 229 and supporting it on the support bar 222.

  Next, the silicon wafer 1 is continuously loaded one by one upstream of the mesh belt 23 of the mesh conveyor 20 by the operation of the destacker 200 (S12). When the first air cylinder 231 of the lift device 230 is driven and the cylinder load 231b moves forward, the table 228 rises together. The ascending of the table 228 is guided in a linear motion by a slide 233b that is slid along the guide rail 233a of the first linear motion guide 233. As the table 228 rises, the uppermost silicon wafer 1-1 among the silicon wafers 1 stacked in the stacking space 221 of the stacker 220 is positioned at the standby position P1 and close to the vacuum pad 251 of the vacuum suction unit 250. When air suction is generated by driving the vacuum pump 252, the uppermost silicon wafer 1-1 is vacuum-sucked by the vacuum pad 251. As shown in FIG. 11, the uppermost silicon wafer 1-1 is separated from the second silicon wafer 1-2 by the compressed air injected through the nozzle 261 of the air blaster 260.

  3, 4, and 12, after the uppermost silicon wafer 1-1 is vacuum-sucked to the vacuum pad 251 of the vacuum suction unit 250, the second air cylinder 242 of the feeder 240 is driven and the cylinder load 242 b is driven. As the head advances, the carriage 243 and the vacuum pad 251 move together toward the front of the arm 241. When the uppermost silicon wafer 1-1 that is vacuum-sucked by the vacuum pad 251 of the vacuum suction unit 250 reaches the mesh belt 23 of the mesh conveyor 20, the driving of the vacuum pump 252 is stopped and air suction input is performed. The uppermost silicon wafer 1-1 is released from the vacuum pad 251 and taken over on the mesh belt 23. When the motor 24 of the mesh conveyor 20 is driven, the driving force of the motor 24 is transmitted to the driving pulley 21 by the belt transmission device 25, and the mesh belt 23 wound between the driving pulley 21 and the driven pulley 22. Is run. As the mesh belt 23 travels, the uppermost silicon wafer 1-1 is transferred from upstream to downstream of the mesh belt 23.

  On the other hand, after the uppermost silicon wafer 1-1 is loaded on the mesh conveyor 20 by the operation of the feeder 240, the second air cylinder 242 is driven and the cylinder load 242b is retracted, whereby the carriage 243 and the vacuum pad 251 are initialized. Return to position. When the vacuum pad 251 returns to the initial position, the second silicon wafer 1-2 is lifted by driving the first air cylinder 231 by the same operation as the above-described lift of the uppermost silicon wafer 1-1, and the vacuum pad 251 is driven. Close contact with. The second silicon wafer 1-2 is loaded upstream of the mesh conveyor 20 by the operation of the feeder 240. On the other hand, the silicon wafer 1 can be manually loaded onto the mesh conveyor 20 by an operator.

  3, 5, and 6, the silicon wafer 1 is transferred along the first tunnel 61 of the blast booth 60 by the operation of the mesh conveyor 20 (S <b> 13), and the grid G is applied to the surface of the transferred silicon wafer 1. To remove pattern 2 (S14). The compressed air is supplied to the nozzle 31 by driving the air compressor 41 of the compressed air supply device 40. The nozzle 31 injects compressed air and grit G onto the surface of the silicon wafer 1 that is transferred on the mesh belt 23. The grit G to be ejected removes the pattern 2 of the silicon wafer 1.

  The powder P is removed from the surface of the silicon wafer 1 from which the pattern 2 has been removed (S15). The silicon wafer 1 from which the pattern 2 has been removed by the first tunnel 61 of the blast booth 60 is transferred to the second tunnel 66 of the cleaning booth 65 by the operation of the mesh conveyor 20. Compressed air is injected through the cleaning nozzle 32 connected to any one of the air pipelines 44 of the compressed air supply device 40, and the powder P remaining on the surface of the silicon wafer 1 is removed by this compressed air. Is done. The silicon wafer 1 from which the powder P has been removed passes through the second tunnel 66 of the cleaning booth 65 and is transferred downstream of the mesh conveyor 20, and the operator moves the silicon wafer 1 from which the pattern 2 has been removed to the mesh conveyor. Unload from 20 downstream. Thus, the silicon wafer 1 from which the pattern 2 is removed is used as a silicon wafer for solar cells, for example.

  As shown in FIG. 3, the powder P containing chips C, dust D, and grit G falling through the mesh belt 23 of the mesh conveyor 20 is guided by the hopper 91 and captured by the first powder pipeline 92. Collected (S16). There is a possibility that the silicon wafer 1 is damaged in the process of removing the pattern 2 by grit blasting. Most of the fragments B generated by the damage of the silicon wafer 1 do not pass through the mesh belt 23, and only a part thereof passes through the mesh belt 23. The debris B falling through the mesh belt 23 is filtered by the first screen filter 94. Therefore, the blockage of the first powder pipeline 92 due to the inflow of the fragments B is prevented.

  1 and 7, the powder P collected in the first powder pipeline 92 of the collection device 90 is supplied to the cyclone separator 100 to separate the dust D from the chips C and grit G. (S17). When the air blower 119 of the dust collector 110 is driven to generate air suction, the powder P collected in the first powder pipeline 92 is separated by a cyclone via the second powder pipeline 93. Supplied to the vessel 100. The second screen filter 95 attached between the first powder pipeline 92 and the second powder pipeline 93 filters chips C having a particle size exceeding 80 μm, for example. By filtering the chip C having a large particle size upstream of the second powder pipe 93, the second powder pipeline 93, the nozzle 31, and the grit pipeline 52 are prevented from being blocked. The powder P flowing into the chamber 102 through the inlet 103 of the housing 101 is separated by the swirling flow. Chips and grit G having a large particle size of, for example, 10 μm or more move and collide with the inner surface of the housing 101 and are discharged through the outlet 104. It is discharged through.

  The chips C and grit G separated and discharged from the chamber 102 of the cyclone separator 100 are supplied again to the tank 51 of the grit supply device 50 (S18). When compressed air is supplied to the air pipeline 44 by the drive of the air compressor 41 and is injected through the nozzle 31, air suction / input is generated in the grit pipeline 52 connected to the nozzle 31. Chips C and grit G discharged from the chamber 102 of the cyclone separator 100 by this air suction and input are collected in the tank 51 via the grit return pipe 53. Chips C and grit G collected in the tank 51 are supplied again to the nozzle 31 of the grit blaster 30.

  Referring to FIGS. 1 and 8, the dust D discharged through the outlet pipe 105 of the cyclone separator 100 is removed by filtering (S19). When the air blower 119 of the dust collector 110 is driven and air suction is generated, the dust D discharged through the outlet pipe 105 of the cyclone separator 100 is discharged into the chamber 112 via the dust pipeline 115 and the inlet 113. And then filtered by the filter 118. When the filter 118 is blocked by the dust D, the air compressor 131 of the air blaster 130 is driven. Compressed air generated by driving the air compressor 131 is supplied to the nozzle 31 through the air pipeline 132, and the dust D is dropped from the filter 118 by the compressed air injected through the nozzle 31. The dust D falling off from the filter 118 is discharged through the outlet 114 and collected in the dust box 120.

  Those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without departing from the technical idea and essential features thereof. For example, while the above description has focused on wafers made of silicone, the present invention can be used to reclaim wafers made of other semiconductor materials, such as gallium silicon and other compound semiconductors. .

  Therefore, the above embodiments are merely illustrative, and the present invention is not limited thereto. In other words, the scope of the present invention should be limited by the scope of the claims rather than the detailed description given above, and any changes or modifications derived from the meaning and scope of the claims and the equivalent concept. Should also be construed as being within the scope of the present invention.

It is a front view which shows the whole structure of the reproduction | regeneration system of the silicon wafer which concerns on this invention. It is a side view of the reproduction | regeneration system shown in FIG. It is sectional drawing which shows the structure of the mesh conveyor, grit blaster, cleaning nozzle, and collection apparatus in the reproduction | regeneration system shown in FIG. It is a side view which shows the structure of the mesh conveyor, grit blaster, cleaning nozzle, and swing apparatus in the reproduction | regeneration system shown in FIG. It is a side view which shows the structure of the mesh conveyor, grit blaster, and swing apparatus in the reproduction | regeneration system shown in FIG. It is a block diagram which shows the structure of the grit blaster in the reproduction | regeneration system shown in FIG. It is sectional drawing which shows the structure of the grit supply apparatus and cyclone separator in the reproduction | regeneration system shown in FIG. It is sectional drawing which shows the structure of the dust collector in the reproduction | regeneration system shown in FIG. It is a block diagram which shows the structure of the controller in the reproduction | regeneration system shown in FIG. It is a perspective view which shows the structure of the destacker in the reproduction | regeneration system of this invention. It is a front view of the destacker shown in FIG. It is a side view of the destacker shown in FIG. It is a top view of the destacker shown in FIG. It is a block diagram which shows the structure of the controller in the destacker shown in FIG. It is sectional drawing which shows the structure of the baking apparatus in the reproduction | regeneration system of this invention. 3 is a flowchart for explaining a method for reclaiming a silicon wafer according to the present invention.

Explanation of symbols

1 Silicon wafer 10 Frame 20 Mesh conveyor 30 Grit blaster 40 Compressed air supply device 50 Grit supply device 60 Blast booth 65 Cleaning booth 70 Swing device 80 Link device 90 Collection device 100 Cyclone separator 110 Dust collector 200 Destacker 210 Frame 220 Stacker 230 Lifting device 240 Feeder 250 Vacuum adsorption unit 260 Air blaster 270 Compressed air supply device 280 Controller 300 Baking device 310 Oven 320 Conveyor

Claims (23)

A mesh conveyor for transferring a semiconductor wafer with the pattern of the semiconductor wafer facing upward;
A grit blaster that is installed above the mesh conveyor and includes one or more projection nozzles that inject grit onto the surface of the semiconductor wafer so that the pattern of the semiconductor wafer is removed;
Swing means for swinging the projection nozzle so as to intersect with a transfer direction of the semiconductor wafer transferred by the mesh conveyor;
The grit falling from the mesh conveyor, a chip, and a collecting means for collecting powder containing dust, which is installed below the mesh conveyor,
A cyclone separating means, connected to the collecting means, for separating the grit and the chips and dust from the powder supplied from the collecting means;
A semiconductor wafer recycling system comprising: a dust collecting means connected to the separating means and collecting the dust discharged from the separating means.   2. The semiconductor wafer regeneration system according to claim 1, wherein the separating means is a cyclone separator. The grit blaster is
A plurality of projection nozzles attached to the upper part of the mesh conveyor along the transfer direction of the semiconductor wafer;
A grit supply device having a tank connected to the projection nozzle and supplying the grit to the projection nozzle;
The semiconductor wafer regeneration system according to claim 1, further comprising a compressed air supply device that supplies compressed air to the projection nozzle.   4. The semiconductor wafer regeneration system according to claim 3, wherein the tank is connected to the separation unit so as to collect the grit and the chips separated by the separation unit.   It is attached so as to be close to the most downstream nozzle among the projection nozzles, and is connected to the compressed air supply device so that the powder remaining on the surface of the semiconductor wafer can be removed by jetting compressed air. The semiconductor wafer regeneration system according to claim 3, further comprising a cleaning nozzle.   A blast booth is installed above the mesh conveyor so as to form a first tunnel surrounding the projection nozzle, and a second tunnel surrounding the cleaning nozzle is formed downstream of the blast booth. 6. The semiconductor wafer regeneration system according to claim 5, wherein a cleaning booth is installed, and the first tunnel and the second tunnel are aligned along a transfer direction of the semiconductor wafer. . The swing means is
A spindle on which the projection nozzle is mounted along the transfer direction of the semiconductor wafer;
A motor having a shaft that provides the rotational force of the spindle;
And a link device coupled to the shaft of the motor so as to convert the rotational force of the motor and transmit the rotational force to the spindle so that the spindle is swung. Item 8. A semiconductor wafer recycling system according to Item 1. The link device is
A disk mounted on the shaft of the motor;
A first link having one end pivotably coupled to the disk;
The second link is connected to the first link so that one end can rotate about a pivot, and the other end is rotatably connected to one end of the spindle. Item 8. A semiconductor wafer recycling system according to Item 7. The collecting means is
A plurality of hoppers mounted below the mesh conveyor and having an inlet for the inflow of the powder and an outlet for the discharge of the powder;
A first powder pipeline connected to the outlet of each of the hoppers;
2. The semiconductor wafer regeneration system according to claim 1, comprising one side of the first powder pipeline and a second powder pipeline connected to the cyclone dust collecting means. A first screen filter attached to an upper part of the inlet of the hopper and capable of filtering debris generated by breakage of the semiconductor wafer;
10. A second screen filter attached upstream of the second powder pipeline and capable of filtering the chips having a particle size larger than that of the grit. The semiconductor wafer recycling system described in 1. The dust collecting means includes
A housing having a chamber coupled to the cyclone separating means;
A plurality of filters attached to the chamber so as to filter dust from the cyclone separating means;
2. The semiconductor wafer regeneration system according to claim 1, further comprising an air blower attached to one side of the housing so that the filtered air of the dust can be discharged from the chamber. .   2. The semiconductor wafer recycling system according to claim 1, further comprising a destacker installed so that the semiconductor wafers can be continuously loaded one by one upstream of the mesh conveyor. The destacker is
A frame installed upstream of the mesh conveyor;
A stacker that is mounted on the upper surface of the frame and has a stacking space in which a plurality of the semiconductor wafers can be stacked with the pattern of the semiconductor wafer facing upward;
A lift device that is attached to the lower part of the stacker and lifts the semiconductor wafer so that the uppermost semiconductor wafer is at the standby position among the plurality of semiconductor wafers loaded in the stacker stacking space;
The loader mounted on an upper part of the frame and holding the uppermost semiconductor wafer positioned at the standby position and loading the uppermost semiconductor wafer upstream of the mesh conveyor. Semiconductor wafer recycling system. The stacker is
Standing up so as to form the stacking space on the upper surface of the frame, the semiconductor wafer can be loaded from the front of the stacking space along the circumferential direction rearward with respect to the horizontal central axis of the stacking space. A plurality of support bars arranged in sequence,
An upper fixing plate and an intermediate fixing plate fixed to the upper end and the center of the support bar, respectively.
14. The semiconductor wafer reclaim according to claim 13, further comprising a table mounted on an upper portion of the intermediate fixing plate so as to be movable up and down along the support bar and on which the semiconductor wafer is placed. system.   A plurality of positioning holes are arranged along the radial direction of each of the upper fixing plate and the table, and a plurality of positioning holes are provided so as to support the outer surface of the semiconductor wafer in the plurality of positioning holes. 15. The semiconductor wafer regeneration system according to claim 14, wherein a bar is mounted. The lift device is
A first air cylinder having a cylinder load standing on the upper surface of the frame and coupled to the lower surface of the table;
A pair of guide rails attached to both sides of the frame so as to face each other; and a pair of slides attached so as to slide along the guide rails and coupled to both sides of the table The semiconductor wafer regeneration system according to claim 13, further comprising a first linear motion guide. The loader is
An arm attached to the top of the frame;
A second air cylinder attached to the top of the arm and having a cylinder load;
A carriage coupled to a cylinder load of the second air cylinder;
A guide rail attached to the upper surface of the arm; and a second linear motion guide having a slide attached to the carriage and attached to the carriage so as to slide along the guide rail;
And a vacuum suction unit having a vacuum pad attached to one side of the lower surface of the carriage and capable of vacuum-sucking the uppermost semiconductor wafer located at the standby position. The semiconductor wafer regeneration system according to claim 13.   Mounted on one side of the frame and compressed so that the uppermost semiconductor wafer is separated from the second semiconductor wafer among the plurality of semiconductor wafers when the semiconductor wafer is vacuum-sucked to the vacuum pad. The semiconductor wafer regeneration system according to claim 13, further comprising an air blaster for injecting air.   2. The semiconductor wafer regeneration system according to claim 1, further comprising baking means for removing moisture and a protective film from the semiconductor wafer. The baking means is
A drying chamber;
An oven having an inlet and an outlet connected to the drying chamber;
A conveyor installed so that the semiconductor wafer can be transferred to the drying chamber via an inlet and an outlet of the oven;
The semiconductor wafer regeneration system according to claim 19, further comprising a heater attached to the drying chamber. Removing moisture from the semiconductor wafer having the pattern by baking;
Transferring the semiconductor wafer with the pattern of the semiconductor wafer facing upward by a mesh conveyor;
Spraying grit onto the surface of the semiconductor wafer with a grit blaster to remove the pattern;
Collecting the grit falling from the mesh conveyor, chips, and powder containing dust under the mesh conveyor; separating the grit and chips from the dust;
Resupplying the grit and chips to be separated to the grit blaster;
Collecting the dust to be separated, and regenerating the semiconductor wafer.   The method of claim 21, further comprising the step of removing powder remaining on the surface of the semiconductor wafer by spraying compressed air after the spraying step.   The method for reclaiming a semiconductor wafer according to claim 21, further comprising a step of filtering debris generated due to the damage of the semiconductor wafer before the step of collecting the powder.

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