Marking device and wafer generation device

Abstract

To trace the history of a wafer while suppressing an increase in man-hours of an operator.SOLUTION: A marking device 1 that marks an ingot 200 on which a release layer is formed to a depth corresponding to the thickness of a wafer to be produced includes a reading unit 4 that reads ingot information formed on an ingot 200, a control unit 90 including a storage portion 93 that stores ingot information read by the reading unit 4, and a marking unit 30 that marks a mark containing ingot information on the wafer to be produced on the basis of the ingot information stored in the storage portion 93.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a marking apparatus and a wafer preparation apparatus. [Background technology]

[0002] Generally, a wire saw is used as a means for cutting wafers from a silicon ingot or a compound semiconductor ingot. In a wire saw, a wire row is formed by winding a number of cutting wires around a number of rollers, and the cutting wire is fed into the ingot to cut it at the wire position.

[0003] However, the cutting depth of the wire saw is relatively large at around 1 mm, and because processes such as lapping and etching are required to flatten the surface after cutting, the amount of material used for the wafer is only about one-third of the original ingot, resulting in poor productivity.

[0004] In view of this, a separation device has been proposed in which a laser beam having a wavelength that is transparent to the ingot is focused inside the ingot and irradiated to form a peeling layer on the intended cutting surface, and then the wafer is separated from the ingot using this peeling layer as a starting point (see, for example, Patent Document 1).

[0005] However, whether a wire saw is used or laser beam irradiation is used, the history of the wafer produced from the ingot is not necessarily clear, and even if a defect occurs in the device during the process of forming the device on the wafer, there is a problem that it is not possible to trace the cause of the device defect by tracing the history of the wafer.

[0006] In order to solve this problem, a method has been proposed in which a peeling layer is formed on a wafer and a manufacturing history is also formed (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2020-72098 A [Patent Document 2] JP 2019-29382 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the method disclosed in Patent Document 2 requires an operator to visually check the manufacturing history formed on the ingot each time and store it in the device, which is not only cumbersome but also a breeding ground for human error.

[0009] The present invention has been made in consideration of the above-mentioned facts, and its object is to provide a marking device and a wafer generation device that make it possible to trace the history of a wafer while suppressing an increase in operator labor. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, the marking device of the present invention is a marking device that performs marking on an ingot in which a peeling layer is formed to a depth corresponding to the thickness of a wafer to be produced, and is characterized in that it comprises a reading unit that reads ingot information formed on the ingot, a control unit including a memory unit that stores the ingot information read by the reading unit, and a marking unit that marks information including the ingot information on the wafer to be produced based on the ingot information stored in the memory unit.

[0011] The wafer production apparatus of the present invention is a wafer production apparatus that produces wafers from an ingot, and is characterized by comprising: a reading unit that reads ingot information formed on the ingot; a control unit including a memory unit that stores the ingot information read by the reading unit; a laser beam irradiation unit that irradiates a laser beam having a wavelength that is transparent to the ingot from the top surface of the ingot at a depth corresponding to the thickness of the wafer to be produced, thereby forming a delamination layer; a marking unit that marks information including the ingot information on the wafer to be produced based on the ingot information stored in the memory unit; and a delamination unit that delaminates a wafer from the ingot starting from the delamination layer formed by the laser beam irradiation unit.

[0012] In the wafer generating apparatus, the ingot information may be formed on a bottom surface of the ingot, and the reading unit may read the ingot information by imaging the ingot from the bottom surface side of the ingot.

[0013] The wafer generating apparatus may further include a transport unit that transports an ingot supported on a tray, and the reading unit may read ingot information formed on the ingot while the ingot is supported on the tray. Effect of the Invention

[0014] The present invention has an effect of making it possible to trace the history of a wafer while suppressing an increase in the number of steps required by an operator. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a marking device according to the first embodiment. [Diagram 2] FIG. 2 is a perspective view of an ingot to be marked by the marking device shown in FIG. [Diagram 3] FIG. 3 is a side view of the ingot shown in FIG. [Figure 4] FIG. 4 is a perspective view of a wafer produced by peeling off a portion of the ingot shown in FIG. [Diagram 5] FIG. 5 is a perspective view showing a state in which a peeling layer is formed on the ingot shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which a separation layer is formed on the ingot shown in FIG. [Figure 7] FIG. 7 is a perspective view showing a configuration example of a wafer generating apparatus according to the second embodiment. [Figure 8] FIG. 8 is a perspective view showing a tray supporting an ingot transported by the ingot transport device of the wafer production apparatus shown in FIG. [Figure 9] FIG. 9 is a perspective view showing a tray, a reading unit, and an ingot of the wafer preparation apparatus shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0017] [Embodiment 1] A marking device 1 according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration example of the marking device according to the first embodiment. FIG. 2 is a perspective view of an ingot to be marked by the marking device shown in FIG. 1. FIG. 3 is a side view of the ingot shown in FIG. 2. FIG. 4 is a perspective view of a wafer produced by peeling off a part of the ingot shown in FIG. 2. FIG. 5 is a perspective view showing a state in which a peeling layer is formed on the ingot shown in FIG. 2. FIG. 6 is a cross-sectional view showing a state in which a peeling layer is formed on the ingot shown in FIG. 2.

[0018] (ingot) The marking device 1 according to the first embodiment shown in Fig. 1 is a device that performs marking on an ingot 200 shown in Fig. 2. The ingot 200 shown in Fig. 2 and Fig. 3, which is the target of marking by the marking device 1 according to the first embodiment, is made of SiC (silicon carbide) in the first embodiment and is formed into a cylindrical shape as a whole. In the first embodiment, the ingot 200 is a hexagonal single crystal ingot.

[0019] As shown in Figs. 2 and 3, the ingot 200 has a first surface 201 which is a circular upper surface, a second surface 202 which is a circular lower surface on the back side of the first surface 201, and a peripheral surface 203 which is continuous with the outer edge of the first surface 201 and the outer edge of the second surface 202. The ingot 200 also has a first orientation flat 204 on the peripheral surface 203 which indicates the crystal orientation of the ingot 200, and a second orientation flat 205 which is perpendicular to the first orientation flat 204 and indicates the crystal orientation of the ingot 200. The orientation flats 204 and 205 are flat planes and form straight lines in a plan view of the ingot 200. The length 204-1 of the first orientation flat 204 is longer than the length 205-1 of the second orientation flat 205.

[0020] The ingot 200 also has a C-axis 208 that is inclined at an off angle α in an inclination direction 207 toward the second orientation flat 205 with respect to a perpendicular line 206 to the first surface 201, and a c-plane 209 that is perpendicular to the C-axis 208. The c-plane 209 is inclined at an off angle α with respect to the first surface 201 of the ingot 200. The inclination direction 207 of the C-axis 208 from the perpendicular line 206 is perpendicular to the extension direction of the second orientation flat 205 and is parallel to the first orientation flat 204.

[0021] An infinite number of c-planes 209 are set in the ingot 200 at the molecular level of the ingot 200. In the first embodiment, the off-angle α is set to 1°, 4°, or 6°, but in the present invention, the ingot 200 can be manufactured by freely setting the off-angle α within the range of, for example, 1° to 6°.

[0022] The ingot 200 has a first surface 201 ground by a grinding device, and then polished by a polishing device to form the first surface 201 into a mirror surface. A portion of the ingot 200 on the first surface 201 side is peeled off, and the peeled portion is generated into the wafer 220 shown in Fig. 4. There are a plurality of types of ingots 200 with different diameters 210.

[0023] The wafer 220 shown in FIG. 4 is manufactured by peeling off a portion including the first surface 201 of the ingot 200 as the wafer 220, and performing grinding, polishing, and the like on the peeled surface 221 peeled off from the ingot 200. After the wafer 220 is peeled off from the ingot 200, a device is formed on the surface. In the first embodiment, the device is a MOSFET (Metal-oxide-semiconductor Field-effect Transistor), a MEMS (Micro Electro Mechanical Systems), or an SBD (Schottky Barrier Diode), but in the present invention, the device is not limited to a MOSFET, a MEMS, or an SBD. Note that the same parts of the wafer 220 as those of the ingot 200 are denoted by the same reference numerals, and description thereof will be omitted.

[0024] 2 and 3, after the separation layer 211 shown in Fig. 3 is formed, a portion of the ingot 200, i.e., a wafer 220 to be produced, is separated and separated starting from the separation layer 211. The separation layer 211 is formed by positioning a focal point 218 of a pulsed laser beam 217 (shown in Figs. 5 and 6) having a wavelength that is transparent to the ingot 200 at a depth 213 (shown in Fig. 6) corresponding to a thickness 222 (shown in Fig. 4) of the wafer 220 to be produced from the first surface 201 of the ingot 200, and irradiating the ingot 200 with the laser beam 217 while moving the ingot 200 along a second orientation flat 205 relative to the laser beam 217.

[0025] When the ingot 200 is irradiated with the laser beam 217, as shown in Figures 5 and 6, SiC is separated into Si (silicon) and C (carbon), and the next irradiated pulsed laser beam 217 is absorbed by the previously formed C, and the SiC is separated into Si and C in a chain reaction, forming a modified portion 214 inside the ingot 200 along the second orientation flat 205, and a crack 215 extending from the modified portion 214 along the c-plane 209 is generated. Thus, when the ingot 200 is irradiated with the pulsed laser beam 217 having a transparent wavelength, a peeling layer 211 including the modified portion 214 and the crack 215 formed from the modified portion 214 along the c-plane 209 is formed inside.

[0026] When the peeling layer 211 is formed over the entire length of the second orientation flat 205, the ingot 200 is moved a predetermined movement distance 219 along the first orientation flat 204 relative to the laser beam 217 (hereinafter referred to as index feed), and then the focal point 218 of the laser beam 217 is positioned at the above-mentioned depth 213, and the ingot 200 is irradiated with the laser beam 217 while being moved relatively along the second orientation flat 205 relative to the laser beam 217 to form the peeling layer 211. The ingot 200 is alternately irradiated with the laser beam 217 while being moved along the second orientation flat 205 relative to the laser beam 217 and index feed are repeated until the peeling layer 211 is formed over the entire lower part of the first surface 201, and the peeling layer 211 is formed over the entire lower part of the first surface 201.

[0027] Moreover, after a portion of the ingot 200, i.e., the wafer 220, is peeled off starting from the peeling layer 211, the peeled surface 212 from which the wafer 220 has been peeled is formed into a mirror surface by grinding and polishing, the peeled surface 212 is formed on the first surface 201, and the peeled layer 211 is formed again to peel off the wafer 220. In this manner, the thickness of the ingot 200 becomes thinner as the wafer 220 is peeled off, and the peeled layer 211 is formed until the predetermined thickness is reached and the wafer 220 is peeled off.

[0028] 2, the ingot 200 has ingot information 216 formed on the second surface 202. The ingot information 216 indicates information related to the ingot 200, and in the first embodiment indicates ID (identification) information indicating the name and symbol of each ingot 200 for identifying the ingots 200 from one another.

[0029] In addition, in the first embodiment, the ingot information 216 is a two-dimensional code, but it may be a one-dimensional code, and may be printed on the second surface 202 or a printed sticker or the like may be attached to form the ingot information 216 on the second surface 202. In the first embodiment, the ingot information 216 is formed in the center of the second surface 202, but in the present invention, the position where the ingot information 216 is formed is not limited to the center of the second surface 202.

[0030] Furthermore, in the present invention, the ingot 200 may have an off angle α of zero degrees, and may be an ingot formed from a material other than SiC, such as GaN (gallium nitride).

[0031] (Marking device) A marking device 1 according to the embodiment 1 will be described. The marking device 1 is a device that performs marking on an ingot 200 in which a peeled layer 211 is formed at a depth corresponding to a thickness 222 of a wafer 220 to be produced. The marking device 1 includes an apparatus main body 2, an ingot placement section 3 installed in the apparatus main body 2, a reading unit 4, a holding table 10, a moving unit 20, a marking unit 30, an imaging unit 40, and a control unit 90.

[0032] The ingot mounting part 3 is a part on which the ingot 200 is mounted. In the first embodiment, the ingot mounting part 3 is disposed next to the holding table 10 of the apparatus body 2. In the first embodiment, the second surface 202 of the ingot 200 is directly mounted on the ingot mounting part 3.

[0033] The reading unit 4 reads the ingot information 216 formed on the second surface 202 of the ingot 200 placed on the ingot placement part 3. In the first embodiment, the reading unit 4 is provided below the ingot placement part 3 and disposed at a position vertically facing the ingot information 216 of the ingot 200 directly placed on the ingot placement part 3. In the first embodiment, the reading unit 4 includes a plurality of imaging elements that capture the ingot information 216 of the ingot 200 directly placed on the ingot placement part 3. The imaging elements are, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element.

[0034] The reading unit 4 images the ingot information 216 of the ingot 200 directly placed on the ingot placement part 3, and outputs the image of the ingot information 216 acquired by imaging to the control unit 90. The reading unit 4 images the ingot information 216 by imaging the ingot 200 from the second surface 202 side of the ingot 200, and outputs the image of the ingot information 216 acquired by imaging to the control unit 90, thereby reading the ingot information 216.

[0035] In the present invention, in embodiment 1, the reading unit 4 is configured by a well-known barcode reader, and the ingot 200 is placed on the ingot placement section 3 with the ingot information 216 facing up, and the ingot information 216 is read from above by the reading unit 4, and the ingot 200 is then turned upside down and transported to the holding table 20 for marking.

[0036] The holding table 10 holds the ingot 200 on a holding surface 11 that is parallel to the horizontal direction. The holding surface 11 of the holding table 10 is made of a porous material such as porous ceramics, and is connected to a suction source such as an ejector. The second surface 202 of the ingot 200 is placed on the holding surface 11 of the holding table 10, and the holding surface 11 is sucked by the suction source, thereby sucking and holding the ingot 200 on the holding surface 11.

[0037] The marking unit 30 marks the wafer 220 to be produced from the ingot 200 held on the holding table 10. In the first embodiment, the marking unit 30 sets a focal point of a pulsed laser beam having a wavelength absorbent for the ingot 200 on the first surface 201 of the ingot 200 held on the holding table 10, and irradiates the ingot 200 with the laser beam to mark the first surface 201 of the ingot 200. In the present invention, the marking unit 30 may set a focal point of a pulsed laser beam having a wavelength transmittable for the ingot 200 inside the ingot 200 held on the holding table 10, and irradiate the ingot 200 with the laser beam to mark the inside of the wafer 220.

[0038] In the first embodiment, the marking unit 30 is supported by a gate-shaped frame 5 erected from the apparatus main body 2, as shown in Fig. 1. The marking unit 30 includes an oscillator that emits a pulsed laser beam 217 for marking the ingot 200, a collector that collects the laser beam 217 emitted from the oscillator on a first surface 201 of the ingot 200 held on the holding surface 11 of the holding table 10, and a focal point moving unit that moves the collector in the vertical direction to change the vertical position of the focal point.

[0039] The moving unit 20 moves the marking unit 30 and the imaging unit 40 relative to the holding table 10 in the X-axis direction, which is parallel to the holding surface 11, the Y-axis direction, and around an axis parallel to the Z-axis direction, which is parallel to the vertical direction. In the first embodiment, the moving unit 20 includes a table moving unit 21 that moves the holding table 10 along the X-axis direction, a marking moving unit 22 that moves the marking unit 30 and the imaging unit 40 in the Y-axis direction, which is perpendicular to the X-axis direction, and a table rotating unit 23 that rotates the holding table 10 around the axis. The table moving unit 21 supports the table rotating unit 23 and moves the holding table 10 together with the table rotating unit 23 in the X-axis direction.

[0040] The imaging unit 40 includes an imaging element that images the ingot 200 held on the holding table 10. The imaging element is, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element. The imaging unit 40 images the ingot 200 held on the holding surface 11 of the holding table 10, obtains an image for performing alignment between the ingot 200 and the marking unit 30, and outputs the obtained image to the control unit 90. In the first embodiment, the imaging unit 40 is supported by a frame 5.

[0041] The control unit 90 controls each of the above-mentioned components of the marking device 1 to cause the marking device 1 to perform the operation of marking the ingot 200. The control unit 90 is a computer having an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory), and an input / output interface device. The arithmetic processing device of the control unit 90 performs arithmetic processing according to a computer program stored in the storage device, and outputs control signals for controlling the marking device 1 to the above-mentioned components of the marking device 1 via the input / output interface device.

[0042] The control unit 90 is connected to a display unit configured with a liquid crystal display device or the like for displaying the status and images of the machining operation, and an input unit (not shown) used by the operator to register machining content information, etc. The input unit is configured with at least one of a touch panel provided on the display unit and an external input device such as a keyboard.

[0043] The control unit 90 also includes a reading unit 91 that generates ID information indicated by the ingot information 216 from an image of the ingot information 216 captured by the reading unit 4, an information generating unit 92 that generates a mark (corresponding to information) including the ID information indicated by the ingot information 216 and to be formed on the ingot 200, and a memory unit 93 that stores the ID information indicated by the ingot information 216 read by the reading unit 4. In the first embodiment, the memory unit 93 stores the ID information generated by the reading unit 91.

[0044] The functions of the reading unit 91 and the information generating unit 92 are realized by the arithmetic processing unit performing arithmetic processing in accordance with a computer program stored in the storage device. The function of the storage unit 93 is realized by the storage device.

[0045] The marking operation of the marking device 1 configured as described above on the ingot 200, i.e., the marking operation, will be described. In the marking device 1, processing conditions are registered in the control unit 90 by an operator, and the second surface 202 of the ingot 200 is placed on the ingot placement part 3. When the control unit 90 of the marking device 1 receives an instruction to start the marking operation from the operator, the marking operation is started.

[0046] In the marking operation, the control unit 90 of the marking device 1 images the ingot information 216 of the ingot 200 using the reading unit 4, and the reading unit 91 generates ID information indicated by the ingot information 216 from the image of the ingot information 216 acquired by imaging, and stores the generated ID information in the memory unit 93.

[0047] In the marking operation, in the marking device 1, the ingot 200 is transported from the ingot placement section 3 to the holding surface 11 of the holding table 10, and the control unit 90 operates the suction source to suction and hold the second surface 202 of the ingot 200 on the holding surface 11 of the holding table 10. In the marking operation, the control unit 90 of the marking device 1 controls the moving unit 20 to move the holding table 10 below the imaging unit 40, and causes the imaging unit 40 to capture an image of the ingot 200.

[0048] Based on the image of the ingot 200 captured by the imaging unit 40, the control unit 90 of the marking device 1 causes the marking unit 30 to face the outer edge portion of the wafer 220 produced from the ingot 200, where no devices are formed, along the vertical direction. In the marking operation, the control unit 90 of the marking device 1 causes the information generating section 92 to generate a mark including ID information.

[0049] Next, in the marking operation, the control unit 90 of the marking device 1 sets the focal point on the first surface 201 of the ingot 200 held on the holding surface 11 of the holding table 10 while moving the focal point and the ingot 200 relatively, and irradiates the ingot 200 with a laser beam from the marking unit 30 to form a mark including ID information on the first surface 201 of the ingot 200. In this way, the marking unit 30 marks the wafer 220 to be generated and to be peeled off from the ingot 200 with a mark including the ID information indicated by the ingot information 216, based on the ID information indicated by the ingot information 216 stored in the storage unit 93.

[0050] In the marking operation, the control unit 90 of the marking device 1 forms a mark including ID information on the first surface 201 of the ingot 200 held on the holding table 10, controls the moving unit 20 to move the holding table 10 to the side of the ingot placement part 3, and then stops suction holding of the ingot 200 on the holding table 10. In the marking operation, the control unit 90 of the marking device 1 ends the marking operation when the ingot 200 is transported from the holding table 10 to the ingot placement part 3.

[0051] As described above, the marking device 1 according to the first embodiment reads the ingot information 216 formed on the second surface 202 of the ingot 200 by the reading unit 4, and forms a mark including the ID information indicated by the ingot information 216 on the wafer 220 to be peeled off from the ingot 200 based on the read ingot information 216. For this reason, the marking device 1 can form the above-mentioned mark on the wafer 220 to be peeled off from the ingot 200 without the operation of an operator.

[0052] As a result, the marking device 1 of embodiment 1 forms the above-mentioned mark on the wafer 220 to be peeled off from the ingot 200 without any operation by an operator, thereby contributing to a reduction in human error and enabling the above-mentioned mark to be formed on the wafer 220 while suppressing an increase in operator labor, thereby making it possible to trace the history of the wafer 220.

[0053] [Embodiment 2] A wafer generating apparatus 100 according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a perspective view showing a configuration example of the wafer generating apparatus according to the second embodiment. FIG. 8 is a perspective view showing a tray supporting an ingot transported by an ingot transport device of the wafer generating apparatus shown in FIG. 7. FIG. 9 is a perspective view showing a tray, a reading unit, and an ingot of the wafer generating apparatus shown in FIG. 7. Note that in FIGS. 7 to 9, the same reference numerals are assigned to the same parts as those of the first embodiment, and description thereof will be omitted.

[0054] The wafer generation apparatus 100 according to the second embodiment is an apparatus that forms a peeling layer 211 in an ingot 200, forms the above-mentioned mark on a first surface 201 of the ingot 200, and then peels the wafer 220 from the ingot 200 starting from the peeling layer 211 to generate the wafer 220 from the ingot 200. As shown in FIG. 7 , the wafer generation apparatus 100 includes an ingot transport device 101, a peeling layer forming device 110, a marking device 1, a peeling device 120, a transfer device 130, and a control unit 90.

[0055] The ingot transport device 101 transports the ingot 200 supported on the tray 60 through the peeling layer forming device 110, the marking device 1, and the peeling device 120. The ingot transport device 101 includes an apparatus main body 102 and a belt conveyor 103 installed on the upper surface of the apparatus main body 102, and transports the tray 60 supporting the ingot 200.

[0056] As shown in Fig. 8 and Fig. 9, the tray 60 includes a rectangular upper wall 61, a rectangular lower wall 62 disposed below the upper wall 61, and a pair of rectangular side walls 63 connecting the upper wall 61 and the lower wall 62. The upper wall 61 and the lower wall 62 are disposed parallel to each other with a gap therebetween, and are disposed parallel to the horizontal direction. The pair of side walls 63 are disposed parallel to each other with a gap therebetween, and are disposed parallel to the vertical direction. As shown in Fig. 9, the upper wall 61 and the lower wall 62 include an imaging window 64 in the center. In the second embodiment, the imaging window 64 is a hole that penetrates the upper wall 61 and the lower wall 62 and has a circular planar shape.

[0057] The upper wall 61 includes an ingot support portion 65 that supports the second surface 202 of the ingot 200 on its upper surface. A plurality of ingot support portions 65 are provided around the imaging window 64, and their upper surfaces are formed parallel to the horizontal direction. A step 66 is formed on the upper surface of the ingot support portion 65 along the outer edge of the ingot 200 having the diameter 210. In the first embodiment, two steps 66 are formed. The ingot support portion 65 positions the ingot 200 at a predetermined position by placing the second surface 202 of the ingot 200 at a position where the outer edge is along the step 66.

[0058] When the second surface 202 of the ingot 200 is placed at a position where the outer edge is along the step 66 of the ingot support portion 65, the ingot information 216 is positioned inside the imaging window 64, as shown in Fig. 9. The lower wall 62 supports the wafer 220 peeled off from the ingot 200 on its upper surface.

[0059] A plurality of belt conveyors 103 are arranged in the Y-axis direction on the upper surface of the device body 2. In the first embodiment, three belt conveyors 103 are provided, each of which corresponds one-to-one to the peeling layer forming device 110, the marking device 1, and the peeling device 120. Each belt conveyor 103 is disposed at an interval in the X-axis direction from the corresponding peeling layer forming device 110, the marking device 1, and the peeling device 120.

[0060] Each belt conveyor 103 includes a pair of support walls 104 spaced apart in the X-axis direction and extending in the Y-axis direction, a plurality of rollers 105 rotatably mounted on the inner surface of each support wall 104 spaced apart in the Y-axis direction, an endless belt 106 wound around the rollers 105, and a motor (not shown) for rotating the rollers 105. The endless belt 106 travels in a circular manner around the outer periphery of the plurality of rollers 105 to transport the tray 60 in the Y-axis direction. In the first embodiment, the ingot transport device 101 transports one tray 60 by the endless belts 106 of the three belt conveyors 103. The ingot transport device 101 also includes a trace stopper (not shown) that can be switched between a state in which the transport of the tray 60 on the endless belts 106 of each belt conveyor 103 is stopped and a state in which the transport of the tray 60 by the endless belts 106 of each belt conveyor 103 is permitted. The trace stopper allows the tray 60 to be transported by the endless belt 106 of each belt conveyor 103 , thereby enabling the tray 60 to move between the endless belts 106 of the belt conveyor 103 .

[0061] In the ingot transport device 101, the belt conveyor 103 rotates the rollers 105 by a motor, and the endless belt 106 moves in a circular manner around the outer periphery of the multiple rollers 105, so that the endless belt 106 moves the tray 60 in the Y-axis direction. By moving the tray 60 in the Y-axis direction, the ingot transport device 101 transports the ingot 200 supported on the tray 60 to the peeling layer forming device 110, the marking device 1, and the peeling device 120 in this order.

[0062] The peeling layer forming apparatus 110, the marking apparatus 1, and the peeling apparatus 120 are arranged in order in the Y-axis direction. The peeling layer forming apparatus 110 forms a peeling layer 211 on the ingot 200. Note that the same parts of the peeling layer forming apparatus 110 as those of the marking apparatus 1 are denoted by the same reference numerals as those of the marking apparatus 1, and the description thereof will be omitted.

[0063] The peeling layer forming apparatus 110 includes a holding table 10 that holds an ingot 200, a laser beam irradiation unit 111 that irradiates a laser beam 217 onto the ingot 200 held on the holding table 10 to form a peeling layer 211, an imaging unit 40 that images the ingot 200 held on the holding table 10, and a moving unit 20 that moves the laser beam irradiation unit 111 and the imaging unit 40 relative to the holding table 10.

[0064] The laser beam irradiation unit 111 is supported by the frame 5, and irradiates a laser beam 217 having a wavelength that is transparent to the ingot 200 held on the holding table 10 at a position corresponding to a depth 213 from a first surface 201 of the ingot 200 that corresponds to a thickness 222 of a wafer 220 to be produced, thereby forming a peeled layer 211 inside the ingot 200. The imaging unit 40 images the ingot 200 held on the holding table 10, obtains an image for performing alignment for aligning the ingot 200 with the laser beam irradiation unit 111, and outputs the obtained image to the control unit 90.

[0065] The peeling device 120 peels off a wafer 220, on which a mark is formed by the marking unit 30 of the marking device, from the ingot 200, starting from the peeling layer 211 formed by the laser beam irradiation unit 111 of the peeling layer forming device 110. Note that the same parts of the peeling device 120 as those of the marking device 1 are given the same reference numerals as those of the marking device 1, and the description thereof will be omitted.

[0066] The peeling apparatus 120 includes a holding table 10 that holds an ingot 200, a peeling unit 121 that applies ultrasonic vibrations to the ingot 200 held on the holding table 10 to break the ingot 200 starting from the peeling layer 211, and a moving unit 20 that moves the peeling unit 121 and the holding table 10 relative to one another.

[0067] The peeling unit 121 is supported by the frame 5 and applies ultrasonic vibrations to the ingot 200 held on the holding table 10 to break the ingot 200 starting from the peeling layer 211 formed by the laser beam irradiation unit 111, thereby peeling off the wafer 220 from the ingot 200.

[0068] The transfer device 130 transports the ingot 200 between the tray 60 transported by the endless belt 106 of each belt conveyor 103 of the ingot transport device 101 and the peeling layer forming device 110, the marking device 1, and the holding table 10 of the peeling device 120. The transfer device 130 includes a plurality of transport units 50 (three in the second embodiment).

[0069] The multiple transport units 50 are arranged in the Y-axis direction, and each of them corresponds to the peeling layer forming device 110, the marking device 1, and the peeling device 120. The transport units 50 transport the ingot 200 between the ingot transport device 101 and any of the peeling layer forming device 110, the marking device 1, and the peeling device 120. The transport unit 50 corresponding to the peeling layer forming device 110 transports the ingot 200 between the ingot support part 65 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the peeling layer forming device 110 and the holding table 10 of the peeling layer forming device 110, thereby transporting the ingot 200 supported by the tray 60.

[0070] The transport unit 50 corresponding to the marking device 1 transports the ingot 200 between the ingot support portion 65 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the marking device 1 and the holding table 10 of the marking device 1.

[0071] The transport unit 50 corresponding to the peeling device 120 transports the ingot 200 from the ingot support portion 65 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the peeling device 120 to the holding table 10 of the peeling device 120. The transport unit 50 corresponding to the peeling device 120 transports the wafer 220, which has been peeled from the ingot 200 held on the holding table 10 of the peeling device 120 starting from the peeling layer 211, to the upper surface of the lower wall 62 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the peeling device 120. The transport unit 50 corresponding to the peeling device 120 transports the ingot 200 held on the holding table 10 of the peeling device 120 and from which the wafer 220 has been peeled, to the ingot support portion 65 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the peeling device 120.

[0072] The transport unit 50 is, for example, a robot pick equipped with a disk-shaped transport pad 51, and transports the ingot 200 by suction-holding it on the transport pad 51.

[0073] In the wafer generating apparatus 100 according to the second embodiment, the reading unit 4 is disposed below the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the marking device 1 on the upper surface of the device body 102 of the ingot transport device 101. That is, the wafer generating apparatus 100 according to the second embodiment is provided with the reading unit 4. In a plan view, the reading unit 4 is positioned inside the imaging window 64 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the marking device 1. The reading unit 4 reads the ingot information 216 of the ingot 200 supported by the ingot support portion 65 of the tray 60 in the same manner as in the first embodiment before the ingot 200 is transported by the transport unit 50 of the transfer device 130 to the holding table 10 of the marking device 1.

[0074] The control unit 90 controls each of the above-mentioned components of the wafer generation apparatus 100 to cause the wafer generation apparatus 100 to perform a generation operation for generating a wafer 220 from an ingot 200. The control unit 90 is a computer having an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory), and an input / output interface device. The arithmetic processing device of the control unit 90 performs arithmetic processing according to a computer program stored in the storage device, and outputs control signals for controlling the wafer generation apparatus 100 to the above-mentioned components of the wafer generation apparatus 100 via the input / output interface device.

[0075] Next, a generating operation for generating a wafer 220 from the ingot 200 of the wafer generating apparatus 100 having the above-mentioned configuration will be described. In the wafer generating apparatus 100, processing conditions are registered in the control unit 90 by an operator, and the second surface 202 of the ingot 200 is placed at a predetermined position on the ingot support portion 65 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the peeling layer forming device 110. When the control unit 90 of the wafer generating apparatus 100 receives an instruction to start the generating operation from the operator, the control unit 90 starts the generating operation.

[0076] In the generating operation, the control unit 90 of the wafer generating apparatus 100 causes the transport unit 50 corresponding to the peeling layer forming device to transport the ingot 200 from the tray 60 to the holding surface 11 of the holding table 10, and the second surface 202 of the ingot 200 is sucked and held on the holding surface 11 of the holding table 10 by the suction force of the suction source. In the generating operation, the control unit 90 of the wafer generating apparatus 100 controls the moving unit 20 to move the holding table 10 below the imaging unit 40, causes the imaging unit 40 to capture an image of the ingot 200, and performs alignment to align the laser beam irradiation unit 111 and the ingot 200 held on the holding table 10.

[0077] In the generating operation, the control unit 90 of the wafer generating apparatus 100 controls the peeling layer forming apparatus 110 to irradiate the ingot 200 held on the holding table 10 with a laser beam 217 from the laser beam irradiation unit 111, thereby forming a peeling layer 211 inside the ingot 200. In the generating operation, after the peeling layer forming apparatus 110 forms the peeling layer 211 on the ingot 200, the control unit 90 of the wafer generating apparatus 100 stops the suction holding of the holding table 10 and controls the transport unit 50, the belt conveyor 103, etc. to transport the ingot 200 on which the peeling layer 211 has been formed to the ingot support portion 65 of the tray 60 transported by the endless belt 106 of the belt conveyor 103 corresponding to the marking device 1.

[0078] In the generating operation, the control unit 90 of the wafer generating apparatus 100 causes the reading unit 4 to capture an image of the ingot information 216 of the ingot 200, and the reading section 91 generates ID information indicated by the ingot information 216 from the captured image of the ingot information 216, and stores the generated ID information in the storage section 93. In the generating operation, the control unit 90 of the wafer generating apparatus 100 causes the transport unit 50 to transport the ingot 200 from the tray 60 to the holding surface 11 of the holding table 10, and causes the marking device 1 to form the above-mentioned mark on the first surface 201 of the ingot 200, i.e., the wafer 220, in the same manner as in the first embodiment.

[0079] In the generating operation, the control unit 90 of the wafer generating apparatus 100 controls the transport unit 50, the belt conveyor 103, etc., to transport the ingot 200 on which the peeling layer 211 and the above-mentioned mark are formed to the holding table 10 of the peeling apparatus 120. In the generating operation, the control unit 90 of the wafer generating apparatus 100 suction-holds the second surface 202 of the ingot 200 on the holding surface 11 of the holding table 10 of the peeling apparatus 120, and causes the peeling unit 121 to apply ultrasonic vibration to the ingot 200 to break the ingot 200 starting from the peeling layer 211. In the generating operation, the control unit 90 of the wafer generating apparatus 100 stops applying ultrasonic vibration and suction-holding the holding table 10 after breaking the ingot 200 starting from the peeling layer 211.

[0080] In the production operation, the control unit 90 of the wafer production apparatus 100 causes the transport unit 50 corresponding to the peeling apparatus 120 to transport the wafer 220 peeled off from the ingot 200 on the holding table of the peeling apparatus 120 to the upper surface of the lower wall 62 of the tray 60, and transports the ingot 200 on the holding table of the peeling apparatus 120 to the ingot support portion 65 of the tray 60. The wafer production apparatus 100 forms the peeled layer 211 and marks until the ingot 200 reaches a predetermined thickness, thereby producing the wafer 220.

[0081] The wafer generating apparatus 100 according to the second embodiment reads the ingot information 216 formed on the second surface 202 of the ingot 200 by the reading unit 4, and forms a mark including the ingot information 216 on the wafer 220 to be peeled off from the ingot 200 based on the read ingot information 216. Therefore, similar to the marking apparatus 1 according to the first embodiment, the above-mentioned mark can be formed on the wafer 220 to be peeled off from the ingot 200 without the operation of an operator. As a result, similar to the marking apparatus 1 according to the first embodiment, the wafer generating apparatus 100 according to the second embodiment can form the above-mentioned mark on the wafer 220 while suppressing an increase in the number of steps of the operator, and has an effect of enabling the history of the wafer 220 to be traced back.

[0082] The present invention is not limited to the above embodiment. In other words, various modifications can be made without departing from the gist of the present invention. In the present invention, the ingot information 216 is not limited to ID information showing the name or code of each ingot 200 for distinguishing between the ingots 200.

[0083] In addition, in the present invention, the reading unit 4 may be provided not only to read the ingot information 216 before transporting the ingot to the marking device 1, but also to read the ingot information 216 before transporting the ingot to the peeling layer forming device 110. That is, in the present invention, the wafer generating apparatus 100 may be provided with a plurality of reading units 4. In addition, in the present invention, the marking device 1 and the wafer generating apparatus 100 may be provided with an additional reading unit for confirmation after marking is completed. [Explanation of symbols]

[0084] 1 Marking device 4 Reading Unit 30 Marking Unit 50 Transport Unit 60 trays 65 Ingot support 90 Control Unit 93 Memory section 100 Wafer Generation Equipment 111 Laser beam irradiation unit 121 Peeling unit 200 Ingots 201 1st side (top side) 202 2nd side (bottom side) 211 Peeling layer 213 Depth 216 Ingot Information 217 Laser Beam 218 Focus point 220 Wafers 222 Thickness

Claims

1. A marking apparatus for marking an ingot having a peeled layer formed at a depth corresponding to a thickness of a wafer to be produced, A reading unit for reading ingot information formed on the ingot; a control unit including a memory unit that stores the ingot information read by the reading unit; a marking unit that marks information including the ingot information on the wafer to be produced based on the ingot information stored in the storage unit; A marking device comprising:

2. A wafer producing apparatus for producing wafers from an ingot, comprising: A reading unit for reading ingot information formed on the ingot; a control unit including a memory unit that stores the ingot information read by the reading unit; a laser beam irradiation unit for irradiating a laser beam having a wavelength that is transparent to the ingot from a position corresponding to a thickness of a wafer to be produced from an upper surface of the ingot to form a peeling layer; a marking unit that marks information including the ingot information on the wafer to be produced based on the ingot information stored in a storage unit; a delamination unit for delaminating a wafer from the ingot starting from a delamination layer formed by the laser beam irradiation unit; A wafer generating apparatus comprising:

3. the ingot information is formed on a lower surface of the ingot; The reading unit comprises: The ingot information is read by imaging the ingot from the underside of the ingot.

3. The wafer preparation apparatus of claim 2.

4. A transport unit that transports the ingots supported on the tray, The reading unit comprises:

4. The wafer generating apparatus according to claim 2, further comprising: a step of reading ingot information formed on the ingot while the ingot is supported on the tray.

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