Method for separating object, method for processing object, and processing apparatus

Abstract

To provide a separation method of an object capable of easily and properly separating the object from a holding surface.SOLUTION: The method includes a liquid ejecting step of ejecting a liquid from the holding surface in a state in which the object is held by the holding surface, a moving step of separating the holding surface and the object from each other while maintaining a state in which the liquid is in contact with both the holding surface and the object by relatively moving the holding surface and the object in directions away from each other after the liquid ejecting step, and a liquid removing step of removing the liquid that is in contact with both the holding surface and the object after the moving step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an object separating method for separating an object held on a holding surface from the holding surface, an object processing method for processing an object, and a processing apparatus for processing an object. [Background technology]

[0002] The device chip manufacturing process uses a wafer in which devices are formed in multiple regions defined by multiple streets (planned division lines) arranged in a grid pattern. Device chips equipped with devices are manufactured by dividing the wafer along the streets into individual pieces. Device chips are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] When dividing a wafer, the wafer is processed by various processing devices. For example, a cutting device that cuts an object with an annular cutting blade, a laser processing device that processes an object with a laser, etc. Also, by subjecting the wafer before division to a thinning process, thin device chips can be obtained. For example, a wafer is thinned by a grinding device that grinds an object, a polishing device that polishes an object, etc.

[0004] Wafers used in the manufacture of device chips are formed by slicing an ingot. For example, a separation layer is formed inside the ingot by performing laser processing on the ingot using a laser processing device. The region of the ingot where the separation layer is formed is more brittle than other regions, so when an external force is applied to the ingot on which the separation layer has been formed, the ingot breaks starting from the separation layer, and wafers are separated from the ingot (see Patent Document 1). Then, the ingot from which the wafers have been separated is subjected to grinding or other processing, and the ingot is reused to manufacture the next wafer.

[0005] As described above, when processing objects such as wafers and ingots in a processing apparatus, the objects are held by a holding unit provided in the processing apparatus. For example, the holding unit has a holding surface connected to a suction source, and the object is held by the holding surface using suction. However, when the object is held by the holding surface of the holding unit using suction, the processed object is difficult to remove from the holding surface, hindering smooth transport of the object. Therefore, when transporting the object from the holding unit, a method is sometimes used to assist in removing the object by spraying a liquid such as water from the holding surface (see Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-111143 [Patent Document 2] Japanese Patent Publication No. 2020-93330 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, after processing the object in the processing device, ejecting liquid from the holding surface promotes the object's detachment from the holding surface. However, if the liquid ejected from the holding surface remains between the object and the holding surface, the surface tension of the liquid acts on the holding surface and the object, causing the object to adhere to the holding surface via the liquid. As a result, despite the liquid being supplied to promote the object's detachment from the holding surface, the liquid makes it difficult for the object to detach from the holding surface, which is an inconvenience.

[0008] To remove an object from the holding surface while the surface tension of the liquid is acting on it, the object must be carefully lifted and pulled away from the holding surface with a strong force. This makes it difficult to smoothly transport the object from the holding unit. Furthermore, applying a strong external force to the object can cause deformation or damage to the object, which can prevent it from being transported properly.

[0009] The present invention has been made in consideration of such problems, and aims to provide a method for separating an object, a method for processing an object, and a processing device that can easily and appropriately separate an object from a holding surface. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a method for separating an object held on a holding surface from the holding surface, the method comprising: a liquid ejection step of ejecting liquid from the holding surface while the object is held by the holding surface; a moving step of moving the holding surface and the object relatively away from each other after the liquid ejection step, thereby separating the object from the holding surface while maintaining the liquid in contact with both the holding surface and the object; and a liquid removal step of removing the liquid that is in contact with both the holding surface and the object after the moving step.

[0011] Preferably, in the liquid removal step, the liquid in contact with both the holding surface and the object is removed by suction with the holding surface. Also, preferably, in the liquid jetting step or the moving step, the object is washed with the liquid jetted from the holding surface. Also, preferably, the object separation method further includes, after the moving step and before the liquid removal step, a cleaning step of washing the object with the liquid jetted from the holding surface while the relative movement between the holding surface and the object is stopped.

[0012] According to another aspect of the present invention, there is provided a method for processing an object, the method comprising: a holding step of holding the object on a holding surface; a processing step of processing the object held on the holding surface after the holding step; a liquid ejection step of ejecting liquid from the holding surface while the object is held by the holding surface after the processing step; a moving step of moving the holding surface and the object relatively in directions away from each other after the liquid ejection step, thereby separating the holding surface and the object while maintaining the liquid in contact with both the holding surface and the object; and a liquid removal step of removing the liquid that is in contact with both the holding surface and the object after the moving step.

[0013] Furthermore, according to another aspect of the present invention, a processing device is provided, comprising: a holding unit having a holding surface for holding an object; a processing unit for processing the object held on the holding surface; a liquid supply source for supplying liquid to the holding unit from being ejected from the holding surface; a removal unit for removing the liquid ejected from the holding surface; and a controller, wherein the controller is capable of causing the removal unit to remove the liquid that is in contact with both the holding surface and the object. [Effects of the Invention]

[0014] In the object separation method, object processing method, and processing apparatus according to one aspect of the present invention, when the object is separated from the holding surface, the liquid in contact with both the holding surface and the object is removed, thereby eliminating the surface tension of the liquid acting on the object and making it possible to easily and appropriately separate the object from the holding surface. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram illustrating a processing system. [Figure 2] FIG. 1 is a perspective view showing a laser processing device. [Figure 3]FIG. 3(A) is a front view showing a separation device that holds an object, and FIG. 3(B) is a front view showing a separation device that separates a substrate from an object. [Figure 4] FIG. [Figure 5] 1 is a flowchart illustrating a method for processing an object. [Figure 6] FIG. 10 is a cross-sectional view showing the processing device in a holding step. [Figure 7] FIG. 2 is a partial cross-sectional front view showing the processing apparatus in a processing step. [Figure 8] FIG. 10 is a partial cross-sectional front view showing the processing apparatus in a liquid ejection step. [Figure 9] FIG. 10 is a partial cross-sectional front view showing the processing device in a moving step. [Figure 10] FIG. 10 is a partial cross-sectional front view showing the processing apparatus in a cleaning step. [Figure 11] FIG. 10 is a partial cross-sectional front view showing the processing apparatus in a liquid removal step. [Figure 12] FIG. 10 is a partial cross-sectional front view showing the processing device in a transport step. [Figure 13] FIG. 10 is a cross-sectional view showing the processing device in a foreign matter removal step. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. First, a configuration example of a processing system equipped with a processing device capable of implementing the object separation method and object processing method according to this embodiment will be described. Figure 1 is a block diagram showing a processing system 2.

[0017] The processing system 2 is a system capable of successively performing multiple processes on the object 11. The object 11 is an object (a workpiece) to be processed by the processing system 2, and in this embodiment, the object 11 is an ingot used to manufacture a substrate (wafer). A substrate of a predetermined thickness is obtained by separating a portion of the ingot from the main body of the ingot. For example, the object 11 is a columnar or disk-shaped single crystal ingot made of a semiconductor material. In this case, a semiconductor wafer is obtained by separating the substrate from the object 11.

[0018] The processing system 2 includes a plurality of processing devices 4A, 4B, and 4C that perform predetermined processing on the object 11. Specifically, the processing device 4A is a processing device (laser processing device) that performs laser processing on the object 11. The processing device 4B is a processing device (separation device) that separates a substrate from the object 11. The processing device 4C is a processing device (grinding device) that grinds the object 11 after the substrate has been separated. The processing devices 4A, 4B, and 4C process the object 11 in sequence, thereby producing a substrate from the object 11. The specific configurations, functions, operations, etc. of the processing devices 4A, 4B, and 4C will be described later (see FIGS. 2 to 4).

[0019] The processing devices 4A, 4B, and 4C are equipped with controllers (control units, control units, control devices) 6A, 6B, and 6C that control the processing devices 4A, 4B, and 4C, respectively. The controller 6A is connected to the components that make up the processing device 4A, and generates control signals that control the operation of each component of the processing device 4A. The controller 6B is connected to the components that make up the processing device 4B, and generates control signals that control the operation of each component of the processing device 4B. The controller 6C is connected to the components that make up the processing device 4C, and generates control signals that control the operation of each component of the processing device 4C.

[0020] For example, the controllers 6A, 6B, and 6C are configured by computers and include a processing unit that executes processes such as calculations required for the operation of the processing devices 4A, 4B, and 4C, and a storage unit that stores various information (data, programs, etc.) used for the operation of the processing devices 4A, 4B, and 4C. The processing unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

[0021] The processing system 2 also includes a transport system 8 that transports the object 11. The transport system 8 includes a transport unit (transport mechanism) 10 that transports the object 11 to the vicinity of the processing devices 4A, 4B, and 4C, and a plurality of transport units (transport mechanisms) 12A, 12B, and 12C that transport the object 11 between the processing devices 4A, 4B, and 4C and the transport unit 10. The transport system 8 circulates and transports the object 11 so that a series of steps in which the object 11 is processed in turn by the processing devices 4A, 4B, and 4C is repeated.

[0022] The transport unit 10 is configured by a belt conveyor or the like, and transports, for example, the object 11 to the vicinity of the transport opening (not shown) of the processing equipment 4A, 4B, 4C. The transport units 12A, 12B, 12C are configured by a transport robot such as an articulated robot, and transfer the object 11 between the processing equipment 4A, 4B, 4C and the transport unit 10. Specifically, the transport unit 12A transports the object 11 between the transport unit 10 and the processing equipment 4A, the transport unit 12B transports the object 11 between the transport unit 10 and the processing equipment 4B, and the transport unit 12C transports the object 11 between the transport unit 10 and the processing equipment 4C.

[0023] Furthermore, the processing system 2 includes a host computer 14 that controls the processing devices 4A, 4B, and 4C and the transport system 8. The host computer 14 is connected to the components of the processing system 2 (processing devices 4A, 4B, and 4C, transport unit 10, and transport units 12A, 12B, and 12C).

[0024] The processing system 2 operates by transmitting and receiving signals between the host computer 14 and each component. For example, the host computer 14 controls the processing of the object 11 by the processing devices 4A, 4B, and 4C by outputting control signals to the controllers 6A, 6B, and 6C. The host computer 14 also controls the transport of the object 11 by the transport system 8 by outputting control signals to the transport unit 10 and the transport units 12A, 12B, and 12C.

[0025] The host computer 14 includes a processing unit that executes processes such as calculations necessary for the operation of the processing system 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the processing system 2. The processing unit is configured to include a processor such as a CPU, and the storage unit is configured to include memories such as a ROM and a RAM.

[0026] When the processing system 2 starts operating, first, the object 11 is transported by the transport unit 10 to the front of the processing device 4A. Then, the object 11 is transported from the transport unit 10 to the processing device 4A by the transport unit 12A, and processed by the processing device 4A. The processing device 4A performs laser processing on the object 11 as described below, thereby forming a separation layer in the object 11 that functions as a starting point for separation (see FIG. 2). After being processed by the processing device 4A, the object 11 is transported from the processing device 4A to the transport unit 10 by the transport unit 12A.

[0027] Next, the object 11 is transported by the transport unit 10 from in front of the processing device 4A to in front of the processing device 4B. Then, the object 11 is transported from the transport unit 10 to the processing device 4B by the transport unit 12B, and is processed by the processing device 4B. The processing device 4B manufactures a substrate from the object 11 by separating a portion of the object 11 as described below (see FIGS. 3(A) and 3(B)). The object 11 processed by the processing device 4B is transported from the processing device 4B to the transport unit 10 by the transport unit 12B.

[0028] Next, the object 11 is transported by the transport unit 10 from in front of the processing device 4B to in front of the processing device 4C. Then, the object 11 is transported from the transport unit 10 to the processing device 4C by the transport unit 12C, and processed by the processing device 4C. The processing device 4C performs a grinding process on the object 11 as described below, thereby flattening the surface of the object 11 (see FIG. 7). The object 11 processed by the processing device 4C is transported from the processing device 4C to the transport unit 10 by the transport unit 12C.

[0029] Then, the object 11 is transported again to the processing device 4A by the transport units 10 and 12A and processed by the processing device 4A. Thereafter, the object 11 is processed by the processing devices 4B and 4C in the same manner. In this way, by repeating the process of processing the object 11 by the processing devices 4A, 4B, and 4C in turn, a plurality of substrates can be efficiently manufactured from the object 11.

[0030] The processing system 2 can process multiple objects 11 simultaneously. For example, while a first object 11 is transported to processing device 4B and processed by processing device 4B, a second object 11 is transported to processing device 4A and processed by processing device 4A. Also, while a first object 11 is transported to processing device 4C and processed by processing device 4C, a second object 11 is transported to processing device 4B and processed by processing device 4B, and a third object 11 is transported to processing device 4A and processed by processing device 4A. This allows multiple objects 11 to be processed efficiently, improving productivity.

[0031] Next, specific examples of the processing devices 4A, 4B, and 4C will be described. As described above, the processing device 4A is a laser processing device that performs laser processing on the object 11, the processing device 4B is a separation device that separates the substrate from the object 11, and the processing device 4C is a grinding device that grinds the object 11.

[0032] Fig. 2 is a perspective view showing a processing device (laser processing device) 4A. The processing device 4A performs laser processing on an object 11 to form a separation layer inside the object 11. In Fig. 2, the X-axis direction (processing feed direction, first horizontal direction, left-right direction) and the Y-axis direction (indexing feed direction, second horizontal direction, front-rear direction) are perpendicular to each other. Furthermore, the Z-axis direction (up-down direction, height direction, vertical direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0033] The object 11 is an ingot formed in a cylindrical or disc shape, and has a first surface (front surface) 11a and a second surface (back surface) 11b that are generally parallel to each other, and a side surface (outer peripheral surface) 11c connected to the first surface 11a and the second surface 11b. For example, when manufacturing wafers made of silicon carbide (SiC), a single-crystal SiC ingot is used as the object 11. The diameter of the ingot is selected according to the diameter of the wafers to be manufactured (6 inches, 8 inches, etc.). The thickness of the ingot is, for example, 500 μm or more and 100 mm or less.

[0034] However, the material of the object 11 can be appropriately selected depending on the material of the wafer to be manufactured. For example, the object 11 may be an ingot made of silicon, gallium oxide, gallium nitride, lithium tantalate (LT), lithium niobate (LN), diamond, etc. Furthermore, if the object 11 is a crystalline material, a cutout portion (notch, orientation flat, etc.) indicating the crystal orientation may be provided on the outer periphery of the object 11.

[0035] The processing device 4A includes a holding unit 20 that holds the object 11. For example, a chuck table is used as the holding unit 20. The upper surface of the holding unit 20 is a flat surface that is roughly parallel to the horizontal plane (XY plane) and forms a circular holding surface 20a that holds the object 11. The holding surface 20a is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), and the like formed inside the holding unit 20.

[0036] The holding unit 20 is connected to a moving unit (not shown) that moves the holding unit 20 and a rotational drive source (not shown) that rotates the holding unit 20. The moving unit is configured with, for example, a ball screw type moving mechanism, and moves the holding unit 20 along the X-axis direction and the Y-axis direction. The rotational drive source is configured with a motor or the like, and rotates the holding unit 20 around a rotation axis that is roughly parallel to the Z-axis direction.

[0037] The processing device 4A also includes a processing unit (laser irradiation unit) 22 that irradiates the object 11 with a laser beam 28. The processing unit 22 includes a laser oscillator (not shown), such as a YAG laser, YVO4 laser, or YLF laser, that emits the pulsed laser beam 28, a housing 24 that is provided above the holding unit 20, and a laser processing head 26. The housing 24 is formed in a hollow cylindrical shape and is arranged along the Y-axis direction. The laser processing head 26 that irradiates the laser beam 28 toward the holding unit 20 is attached to the tip of the housing 24.

[0038] The housing 24 and the laser processing head 26 house an attenuator that adjusts the output of the laser beam 28 emitted from the laser oscillator, an optical system that guides the laser beam 28 emitted from the laser oscillator to the object 11 held by the holding unit 20, and the like. The optical system is configured to include optical elements such as lenses, mirrors, polarizing beam splitters (PBS), diffractive optical elements (DOE), and LCOS-SLMs (Liquid Crystal on Silicon - Spatial Light Modulators), and controls the traveling direction, shape, focusing position, etc. of the laser beam 28.

[0039] In particular, a condenser (not shown), which is a component of the optical system, is housed in the laser processing head 26. The condenser has a focusing lens such as an fθ lens, and focuses the laser beam 28 to irradiate the object 11. When the laser processing head 26 irradiates the object 11 with the laser beam 28, laser processing is performed on the object 11.

[0040] An imaging unit 30 that captures an image of a subject is also attached to the processing unit 22. For example, the imaging unit 30 is fixed to the housing 24 and installed adjacent to the laser processing head 26. The imaging unit 30 includes an image sensor such as a CCD (Charged-Coupled Devices) sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor, and captures an image of the object 11 held by the holding unit 20. There are no limitations on the type of imaging unit 30, and a visible light camera or an infrared camera, for example, may be used.

[0041] The imaging unit 30 captures an image of the object 11. Then, based on the image captured by the imaging unit 30, the alignment of the object 11 with the laser processing head 26, confirmation of the state of the object 11, etc. are performed.

[0042] The housing 24 may be connected to a moving unit (not shown) that moves the housing 24. For example, the moving unit is configured with a ball screw type moving mechanism, and moves (raises and lowers) the housing 24 along the Z-axis direction together with the laser processing head 26 and the imaging unit 30. This makes it possible to adjust the height position of the focal point of the laser beam 28 and to focus the imaging unit 30.

[0043] When processing the object 11 in the processing device 4A, the object 11 is first held by the holding unit 20. For example, the object 11 is placed on the holding unit 20 so that the first surface 11a is exposed upward and the second surface 11b faces the holding surface 20a. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 20a, the object 11 is sucked and held by the holding unit 20.

[0044] Next, the processing unit 22 is activated, and the laser processing head 26 irradiates the object 11 with a laser beam 28. This performs laser processing on the object 11. The irradiation conditions of the laser beam 28 are set so that a separation layer that functions as a separation starting point is formed inside the object 11.

[0045] Specifically, the irradiation conditions of the laser beam 28 are set so that the region inside the object 11 irradiated with the laser beam 28 is modified (transformed) to form a modified portion (transformed portion) 13. More specifically, the wavelength of the laser beam 28 is set so that at least a portion of the laser beam 28 passes through the object 11. In other words, the laser beam 28 is absorbent by the object 11. Other irradiation conditions of the laser beam 28 are also set appropriately so that the modified portion 13 is appropriately formed in the object 11. For example, when the object 11 is a SiC ingot, the irradiation conditions of the laser beam 28 can be set as follows. Wavelength: 1064nm Average power output: 2-4.5W Repetition frequency: 80kHz Processing feed rate: 120~260mm / s

[0046] When irradiating the object 11 with the laser beam 28, first, the object 11 is imaged by the imaging unit 30, and a captured image of the first surface 11a of the object 11 is obtained. Then, based on the captured image, the positional relationship between the object 11 and the laser processing head 26 is adjusted. Specifically, the position of the holding unit 20 in the X-axis direction is adjusted so that the laser processing head 26 is positioned outside the object 11 in the X-axis direction. Furthermore, the position of the holding unit 20 in the Y-axis direction is adjusted so that the edge of the object 11 and the laser processing head 26 are positioned in the Y-axis direction.

[0047] Furthermore, the height position of the focal point of the laser beam 28 is adjusted to coincide with the height position inside (between the first surface 11a and the second surface 11b) of the object 11. The difference in height between the first surface 11a of the object 11 and the focal point of the laser beam 28 at this time corresponds to the depth of the modified portion 13 formed inside the object 11.

[0048] Then, while irradiating the laser beam 28 from the laser processing head 26, the holding unit 20 is moved along the X-axis direction at a predetermined processing feed speed, and the object 11 and the laser processing head 26 are moved relatively along the X-axis direction (processing feed). As a result, with the focal point of the laser beam 28 positioned inside the object 11, the laser beam 28 is irradiated from the first surface 11a side of the object 11, and scans the object 11 from one end to the other in the X-axis direction.

[0049] When the laser beam 28 is irradiated onto the object 11 as described above, the area inside the object 11 irradiated with the laser beam 28 expands, causing a disturbance (distortion) in the crystal structure, thereby modifying the object 11. As a result, a linear modified portion 13 is formed inside the object 11 along the X-axis direction.

[0050] Thereafter, the holding unit 20 is moved along the Y-axis direction by a predetermined index amount (for example, about 250 to 400 μm), and the object 11 and the laser processing head 26 are moved relatively along the Y-axis direction (indexing feed). Then, processing feed is performed while irradiating the laser beam 28 from the laser processing head 26 in the same procedure as above. By repeating this operation, multiple substantially parallel modified regions 13 are formed at a predetermined interval at a predetermined depth position inside the object 11.

[0051] The laser beam 28 may be irradiated onto the object 11 only on the outgoing path of the processing feed, or on both the outgoing and return paths of the processing feed. Instead of moving the holding unit 20, the laser processing head 26 may be moved to scan the laser beam 28. Instead of moving the holding unit 20 or the laser processing head 26, a scanning optical system for scanning the laser beam 28 may be mounted on the processing unit 22. For example, the scanning optical system may include optical elements such as a galvanometer scanner, an acousto-optical device (AOD), and a polygon mirror.

[0052] When the laser beam 28 is scanned with the focal point of the laser beam 28 positioned at a predetermined depth inside the object 11, the object 11 is modified at the focal point and its vicinity, forming a linear modified region 13. Furthermore, internal stress acts in the modified region 13, causing multiple fine cracks to form, and the cracks extend from the modified region 13 in a direction intersecting the thickness direction of the object 11. Then, by forming multiple modified regions 13 at predetermined intervals, the modified regions 13 and cracks are formed throughout the entire object 11.

[0053] When the modified portion 13 and cracks are formed as described above, a separation layer (modified layer) 15 is formed at a predetermined depth position inside the object 11. The separation layer 15 corresponds to the region inside the object 11 where the modified portion 13 or cracks are formed. The depth at which the separation layer 15 of the object 11 is formed (the distance between the first surface 11a of the object 11 and the separation layer 15) corresponds to the thickness of the substrate to be separated from the object 11 by the processing device 4B (see FIGS. 3(A) and 3(B)) in a later step.

[0054] The region of object 11 where separation layer 15 is formed has lower mechanical strength and is more fragile than other regions of object 11. Therefore, separation layer 15 functions as a separation starting point (a trigger for separation) when separating the substrate from object 11. Specifically, when an external force is applied to object 11, the first surface 11a side of object 11 breaks starting from separation layer 15, and a substrate of a predetermined thickness is separated from object 11.

[0055] 3(A) and 3(B) show an example of the configuration of the processing device (separation device) 4B. The processing device 4B separates the substrate (plate-like object) 21 from the object 11 by applying an external force to the object 11.

[0056] The processing device 4B includes a holding unit 40 that holds the object 11. For example, a chuck table is used as the holding unit 40. The upper surface of the holding unit 40 is a flat surface that is roughly parallel to the horizontal plane, and forms a circular holding surface 40a that holds the object 11. The holding surface 40a is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), and the like formed inside the holding unit 40.

[0057] The processing device 4B also includes a processing unit (separation unit) 42 provided above the holding unit 40. The processing unit 42 includes a holding unit 44 that holds the surface (first surface 11a) of the object 11 opposite to the surface (second surface 11b) held by the holding unit 40. The lower surface of the holding unit 44 is a flat surface that is approximately parallel to the horizontal plane, and forms a circular holding surface 44a that holds the object 11.

[0058] For example, the holding unit 44 is configured by a disk-shaped holding member and has a plurality of suction ports (not shown) that suck the target object 11. One end of the suction port is open on the holding surface 44a, and the other end of the suction port is connected to a suction source (not shown) such as an ejector via a flow path (not shown) formed inside the holding unit 44. The number and arrangement of the suction ports are set appropriately so that the plurality of suction ports are blocked by the target object 11 when the holding surface 44a comes into contact with the target object 11.

[0059] A columnar support member 46 that supports the holding unit 44 is connected to the upper end side of the holding unit 44. The lower end of the support member 46 is fixed to the center of the holding unit 44. A moving unit (not shown) that moves the support member 46 is connected to the upper end side of the support member 46. For example, the moving unit is configured with a ball screw type moving mechanism, and moves (raises and lowers) the support member 46 together with the holding unit 44 in the vertical direction.

[0060] 3(A) is a front view showing processing device 4B holding object 11. When separating the substrate from object 11, object 11 is first held by holding units 40 and 44.

[0061] Specifically, the object 11 is placed on the holding unit 40 with a space wider than the thickness of the object 11 secured between the holding surface 40a of the holding unit 40 and the holding surface 44a of the holding unit 44. At this time, the object 11 is placed so that the first surface 11a side is exposed upward and the second surface 11b side faces the holding surface 40a. Then, the suction force (negative pressure) of the suction source is applied to the holding surface 40a, whereby the object 11 is sucked and held by the holding unit 40.

[0062] Next, the holding unit 44 is lowered vertically by a moving unit (not shown) so that the holding surface 44a comes into contact with the first surface 11a of the object 11. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 44a, the object 11 is sucked and held by the holding unit 44. As a result, the second surface 11b side of the object 11 is fixed to the holding surface 40a, and the first surface 11a side of the object 11 is fixed to the holding surface 44a.

[0063] FIG. 3(B) is a front view showing a processing apparatus 4B that separates the substrate 21 from the object 11. After the object 11 is fixed to the holding unit 40 and the holding unit 44, the holding unit 44 is raised vertically by a moving unit (not shown) while the position of the holding unit 40 is fixed. As a result, the holding surfaces 40a and 44a move relatively away from each other, and an external force is applied to the object 11 that separates the first surface 11a and the second surface 11b of the object 11. As a result, the object 11 is broken starting from the separation layer 15, and the substrate 21 corresponding to the first surface 11a of the object 11 is separated from the rest of the object 11. In this manner, the substrate 21 is produced from the object 11.

[0064] Substrate 21 has a first surface (front surface) 21a and a second surface (back surface) 21b that are generally parallel to each other. Second surface 21b of substrate 21 corresponds to a separation surface (fracture surface) formed by separation of substrate 21. Furthermore, the depth at which separation layer 15 of object 11 is formed before separation of substrate 21 (the distance between the first surface of object 11 and separation layer 15) corresponds to the thickness of substrate 21 separated from object 11.

[0065] After the substrate 21 is separated from the object 11, the object 11 is used again to manufacture the substrate 21. However, unevenness remains as fracture marks on the first surface 11a (separated surface, fractured surface) of the object 11 that is newly formed by the separation of the substrate 21. Therefore, after the substrate 21 is separated from the object 11, the object 11 is ground and flattened by the processing device 4C.

[0066] 4 is a perspective view showing a processing device (grinding device) 4C. The processing device 4C removes or reduces unevenness remaining on the first surface 11a of the object 11 by grinding the first surface 11a of the object 11. In FIG. 4, the X-axis direction (first horizontal direction) and the Y-axis direction (second horizontal direction) are perpendicular to each other. Furthermore, the Z-axis direction (up-down direction, height direction, vertical direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0067] The processing device 4C includes a holding unit 50 that holds the object 11. For example, a chuck table is used as the holding unit 50. The upper surface of the holding unit 50 forms a holding surface 50a that holds the object 11.

[0068] Specifically, the holding unit 50 includes a cylindrical frame (main body) 52 made of a metal such as stainless steel (SUS), glass, ceramics, resin, or the like. A cylindrical recess 52b is provided in the center of an upper surface 52a of the frame 52. A disk-shaped holding member 54 made of a porous material such as porous ceramics is fitted into the recess 52b of the frame 52. The holding member 54 includes a large number of pores that communicate from the upper surface to the lower surface of the holding member 54.

[0069] The upper surface of the holding member 54 forms a circular suction surface 54a that sucks the object 11 when the object 11 is held by the holding unit 50. The upper surface 52a of the frame 52 and the suction surface 54a of the holding member 54 form the holding surface 50a of the holding unit 50.

[0070] The holding surface 50a is connected to a flow path 56 via pores contained in the holding member 54 and a flow path 50b (see FIG. 6, etc.) provided inside the frame 52. The flow path 56 is a piping constructed of a tube, a pipe, etc. One end of the flow path 56 is connected to the holding surface 50a (suction surface 54a) via a rotary joint (not shown), the flow path 50b inside the holding unit 50 (see FIG. 6, etc.), and the pores contained in the holding member 54.

[0071] A suction source 58A such as an ejector, a liquid supply source 58B that supplies a liquid such as water, and a gas supply source 58C that supplies a gas such as air or nitrogen gas are connected to the other end of the flow path 56. A valve 60A is connected between the flow path 56 and the suction source 58A, a valve 60B is connected between the flow path 56 and the liquid supply source 58B, and a valve 60C is connected between the flow path 56 and the gas supply source 58C.

[0072] For example, the valves 60A, 60B, and 60C are configured by electromagnetic valves and are connected to a controller 6C (see FIG. 1) of the processing device 4C. The controller 6C outputs control signals to the valves 60A, 60B, and 60C to control the opening and closing of the valves 60A, 60B, and 60C. This controls the decompression of the flow path 56 by the suction source 58A, the presence or absence and flow rate (supply amount) of liquid supplied from the liquid supply source 58B to the flow path 56, and the presence or absence and flow rate (supply amount) of gas supplied from the gas supply source 58C to the flow path 56.

[0073] When the valve 60A is opened while the valves 60B and 60C are closed, the suction force (negative pressure) of the suction source 58A acts on the holding surface 50a, thereby making it possible to suck and hold the object 11 placed on the holding surface 50a.

[0074] When valve 60B is opened with valves 60A and 60C closed, liquid is supplied from liquid supply source 58B to flow path 56 at a predetermined flow rate, causing the liquid to be ejected from holding surface 50a. Furthermore, when valve 60C is opened with valves 60A and 60B closed, gas is supplied from gas supply source 58C to flow path 56 at a predetermined flow rate, causing the gas to be ejected from holding surface 50a. Furthermore, when valves 60B and 60C are opened with valve 60A closed, the liquid supplied from liquid supply source 58B and the gas supplied from gas supply source 58C are mixed in flow path 56, causing a mixed fluid containing the liquid and the gas to be ejected from holding surface 50a.

[0075] Furthermore, a pressure gauge 62 that measures the pressure of the flow path 56 is connected to the flow path 56. The pressure gauge 62 measures the pressure of the flow path 56 constantly or at predetermined timings, and outputs the result to the controller 6C (see FIG. 1). This allows the pressure of the flow path 56 to be monitored by the controller 6C. Then, based on the pressure measured by the pressure gauge 62, the controller 6C can determine whether the holding state of the object 11 by the holding unit 50 is appropriate (whether the object 11 is being appropriately suction-held, whether the suction-holding of the object 11 has been appropriately released, etc.).

[0076] Furthermore, a moving unit 64 that moves the holding unit 50 in the horizontal direction (XY plane direction) is connected to the holding unit 50. For example, the moving unit 64 is configured with a ball screw type moving mechanism, a turntable, etc. By outputting a control signal from the controller 6C (see FIG. 1) to the moving unit 64, the holding unit 50 can be moved in the horizontal direction and placed at a desired position.

[0077] Furthermore, a rotation drive source (not shown), such as a motor, that rotates the holding unit 50 around a rotation axis 50c is connected to the holding unit 50. The rotation axis 50c of the holding unit 50 is set along a direction perpendicular to the radial direction of the holding surface 50a and intersects with the holding surface 50a so as to pass through the center of the holding surface 50a.

[0078] The processing device 4C also includes a processing unit (grinding unit) 66 that grinds the target object 11. The processing unit 66 is provided above the holding unit 50 and includes a cylindrical spindle 68 arranged along the Z-axis direction. A disk-shaped wheel mount 70 made of metal such as SUS (stainless steel) is fixed to the tip end (lower end) of the spindle 68. A rotation drive source (not shown) such as a motor is also connected to the base end (upper end) of the spindle 68.

[0079] An annular grinding wheel 72 for grinding the object 11 is attached to the underside of the wheel mount 70. For example, the grinding wheel 72 is detachably fixed to the wheel mount 70 by a fastener such as a bolt.

[0080] The grinding wheel 72 includes an annular wheel base 74. The wheel base 74 is made of a metal such as aluminum or stainless steel, and is formed to have approximately the same diameter as the wheel mount 70. The upper surface of the wheel base 74 is fixed to the lower surface of the wheel mount 70. A plurality of grinding stones 76 are fixed to the lower surface of the wheel base 74. For example, the grinding stones 76 are formed in a rectangular parallelepiped shape, and are arranged in a ring shape at approximately equal intervals along the outer periphery of the wheel base 74. The lower surfaces of the grinding stones 76 form a grinding surface that grinds the object 11.

[0081] The grinding wheel 76 is formed by fixing abrasive grains made of diamond, cBN (cubic boron nitride), or the like with a bonding material (bond material) such as a metal bond, a resin bond, or a vitrified bond. However, there are no restrictions on the material, shape, structure, size, etc. of the grinding wheel 76. The number of grinding wheels 76 can also be set arbitrarily.

[0082] When the rotation drive source connected to the spindle 68 is operated, the spindle 68, wheel mount 70, and grinding wheel 72 rotate around the rotation axis 66a that is generally parallel to the Z-axis direction. As a result, each of the multiple grinding wheels 76 revolves around the rotation axis 66a along a circular revolving path that is generally parallel to the horizontal plane (XY plane).

[0083] Furthermore, a moving unit 78 that moves (lifts and lowers) the processing unit 66 along the Z-axis direction is connected to the processing unit 66. For example, the moving unit 78 is configured with a ball screw type moving mechanism. By outputting a control signal from the controller 6C (see FIG. 1) to the moving unit 78, the moving unit 78 is activated and the processing unit 66 is lifted and lowered. As a result, the holding unit 50 and the grinding wheel 72 move relatively along the Z-axis direction, and the holding surface 50a of the holding unit 50 and the grinding wheel 72 move closer to or farther apart from each other.

[0084] After the substrate 21 is separated from the object 11 by the processing device 4B (see FIG. 3(B)), the first surface 11a side of the object 11 is ground by the processing device 4C. As a result, unevenness remaining on the first surface 11a (separated surface, fractured surface) side of the object 11 is removed or reduced, and the first surface 11a side of the object 11 is flattened. Thereafter, the object 11 is reused to form the next substrate 21.

[0085] Next, a specific example of an object processing method for processing the object 11 will be described. In this embodiment, as a representative example, a procedure for processing the object 11 by the processing device 4C will be described. Fig. 5 is a flowchart showing the object processing method.

[0086] The object processing method according to this embodiment includes a holding step S1 in which the object 11 is held on the holding surface 50a of the holding unit 50, a processing step S2 in which the object 11 is processed by the processing unit 66, and a separation step S3 in which the object 11 is separated from the holding surface 50a. The separation step S3 corresponds to the object separation method according to this embodiment. Each step will be described in detail below.

[0087] First, the target object 11 is held by the holding surface 50a (holding step S1). Fig. 6 is a cross-sectional view showing the processing device 4C in the holding step S1. In the holding step S1, the target object 11 is suction-held by the holding surface 50a of the holding unit 50 provided in the processing device 4C.

[0088] Specifically, first, the target object 11 is transported by a predetermined transport unit (not shown) and placed on the holding surface 50a of the holding unit 50. At this time, the target object 11 is placed on the holding unit 50 so that the first surface 11a (surface to be ground) is exposed upward and the second surface 11b (surface to be held) faces the holding surface 50a. In addition, the target object 11 is placed concentrically with the holding surface 50a so that the entire suction surface 54a is covered by the second surface 11b of the target object 11.

[0089] Then, with valves 60B and 60C closed, valve 60A is opened. This connects suction source 58A to suction surface 54a via flow paths 56 and 50b and pores inside holding member 54, and the suction force (negative pressure) of suction source 58A acts on suction surface 54a and second surface 11b of object 11. As a result, object 11 is suction-held on holding surface 50a.

[0090] When the object 11 is held by the holding surface 50a, a protective sheet (not shown) for protecting the object 11 may be attached to the second surface 11b side of the object 11. For example, the protective sheet may be a tape having an adhesive layer formed on a base material, or a thermocompression sheet that does not have an adhesive layer and can be thermocompressed to the object 11. In this case, the object 11 is suction-held on the holding surface 50a via the protective sheet.

[0091] Next, the object 11 held by the holding surface 50a is processed (processing step S2). Figure 7 is a partial cross-sectional front view showing the processing device 4C in processing step S2. In processing step S2, the object 11 is ground by the processing unit 66.

[0092] Specifically, first, the holding unit 50 is positioned below the processing unit 66. At this time, the positional relationship between the holding unit 50 and the processing unit 66 is adjusted so that the rotation axis of the holding unit 50 (the center of the object 11) and the rotation path of the grinding wheel 76 overlap in the Z-axis direction. Then, while rotating the holding unit 50 and the grinding wheel 72 at a predetermined speed, the processing unit 66 is lowered along the Z-axis direction. As a result, the multiple grinding wheels 76 approach the object 11 while rotating and come into contact with the first surface 11a side of the object 11.

[0093] When the multiple grinding wheels 76 come into contact with the first surface 11a side of the object 11, the first surface 11a side of the object 11 is scraped off and ground. As a result, any unevenness remaining on the first surface 11a side of the object 11 is removed or reduced, and the first surface 11a side of the object 11 is flattened. Then, after the object 11 has been ground and thinned to a predetermined thickness, the processing unit 66 is raised and grinding is stopped.

[0094] During grinding of the object 11, a liquid (grinding fluid) such as pure water is supplied to the grinding surface (first surface 11a) of the object 11 and the grinding wheel 76. This cools the object 11 and the grinding wheel 76, and also washes away chips generated by grinding the object 11.

[0095] When grinding of the object 11 is completed, the object 11 is carried out from the processing device 4C. Specifically, a separating step S3 is performed in which the object 11 is separated from the holding surface 50a of the holding unit 50 and carried out from the processing device 4C. The separating step S3 will be described in detail below.

[0096] In the separating step S3, first, while the object 11 is held by the holding surface 50a, liquid is ejected from the holding surface 50a (liquid ejecting step S31). Fig. 8 is a partial cross-sectional front view showing the processing device 4C in the liquid ejecting step S31.

[0097] The processing device 4C includes a transport unit 80 that transports the object 11. The transport unit 80 includes a holding unit 82 that holds the surface (first surface 11a) of the object 11 opposite to the surface (second surface 11b) held by the holding surface 50a. The lower surface of the holding unit 82 is a flat surface that is approximately parallel to the horizontal plane (XY plane), and forms a holding surface 82a that holds the object 11.

[0098] For example, the holding unit 82 is formed of a cylindrical holding member and has a plurality of suction ports (not shown) that suck the target object 11. One end of the suction port is open at the holding surface 82a. Meanwhile, the other end of the suction port is connected to a suction source 84 such as an ejector via a flow path (not shown) formed inside the holding unit 82. The number and arrangement of the suction ports are appropriately set so that the plurality of suction ports are blocked by the target object 11 when the holding surface 82a comes into contact with the target object 11.

[0099] However, there are no limitations on the type, configuration, etc. of the holding unit 82 as long as it is capable of holding the object 11. For example, the holding unit 82 may be provided with a plurality of suction pads that suck the object 11. In this case, the plurality of suction pads are each connected to the suction source 84. The holding unit 82 may also be provided with a clamping mechanism that grips and holds the object 11.

[0100] A moving unit 86 that moves the holding unit 82 in the horizontal direction (XY plane direction) and the vertical direction (Z-axis direction) is connected to the holding unit 82. For example, the moving unit 86 includes a moving mechanism (a ball screw type moving mechanism, a transport arm, etc.) that moves the holding unit 82 in the horizontal direction, and an elevating mechanism (a ball screw type moving mechanism, a linear actuator, an air cylinder, etc.) that moves the holding unit 82 in the Z-axis direction. The moving unit 86 may also be a transport robot such as an articulated robot that can move the holding unit 82 to any position.

[0101] In the liquid ejection step S31, first, the target object 11 is held by the transport unit 80. Specifically, the holding unit 82 is moved by the moving unit 86, and the holding unit 82 is positioned directly above the target object 11. Next, the holding unit 82 is lowered along the Z-axis direction by the moving unit 86, and the holding surface 82a is brought into contact with the first surface 11a side of the target object 11. In this state, when the suction force (negative pressure) of the suction source 84 is applied to the holding surface 82a, the target object 11 is sucked and held by the holding surface 82a.

[0102] Next, while keeping valve 60C closed, valve 60A is closed and valve 60B is opened. This disconnects flow path 56 from suction source 58A and connects liquid supply source 58B to flow path 56. As a result, the vacuum in flow paths 50b and 56 is released, the pressure in flow paths 50b and 56 increases, and liquid is supplied from liquid supply source 58B to flow path 56.

[0103] The liquid supplied to the flow path 56 is supplied to the holding surface 50a (suction surface 54a) through the flow path 50b and pores inside the holding member 54, and is sprayed from the holding surface 50a toward the second surface 11b of the object 11. This makes it easier for the object 11 to separate from the holding surface 50a, and assists in the separation of the object 11 from the holding surface 50a.

[0104] Furthermore, in the liquid ejecting step S31, the liquid is ejected from the holding surface 50a for a predetermined period of time, so that the liquid is continuously supplied to the second surface 11b side of the object 11. This cleans the second surface 11b side of the object 11, and foreign matter (machining debris, particles, etc.) adhering to the second surface 11b side of the object 11 is removed.

[0105] Note that, when the flow rate of the liquid supplied from liquid supply source 58B to flow path 56 is sufficiently high relative to the suction force of suction source 58A, the liquid can be ejected from holding surface 50a even if flow path 56 remains connected to suction source 58A. In this case, it is not necessarily necessary to close valve 60A to cut off the connection between flow path 56 and suction source 58A.

[0106] Next, the holding surface 50a and the object 11 are relatively moved in directions away from each other, thereby separating the holding surface 50a and the object 11 while maintaining the liquid in contact with both the holding surface 50a and the object 11 (moving step S32). Fig. 9 is a partial cross-sectional front view showing the processing device 4C in moving step S32.

[0107] In the movement step S32, with the liquid 88, such as water, being ejected from the holding surface 50a, the moving unit 86 slightly raises the holding unit 82 in a direction intersecting the holding surface 50a (the Z-axis direction). As a result, the holding surface 50a and the object 11 move relatively away from each other, and the object 11 is pushed up by the liquid 88 and moves away from the holding surface 50a. At this time, the liquid 88 remains between the holding surface 50a and the object 11 because it is being ejected continuously from the holding surface 50a.

[0108] Here, in the movement step S32, the amount of relative movement between the holding surface 50a and the object 11 (the amount of lift of the holding unit 82) is set so that the liquid 88 remains in contact with both the holding surface 50a and the object 11. Therefore, immediately after the object 11 is separated from the holding surface 50a, the liquid 88 enters between the holding surface 50a and the object 11, and the liquid 88 remains in contact with the holding surface 50a and the second surface 11b of the object 11. The amount of relative movement between the holding surface 50a and the object 11 (the gap between the holding surface 50a and the object 11) in the movement step S32 is set appropriately depending on the properties (hydrophilicity, etc.) of the object 11 and the liquid 88, and is, for example, 2 mm or more and 4 mm or less.

[0109] During the movement step S32, the liquid 88 is continuously ejected from the holding surface 50a, so that the liquid 88 is continuously supplied to the second surface 11b side of the object 11. This allows the second surface 11b side of the object 11 to be cleaned in the movement step S32 following the liquid ejection step S31.

[0110] Next, with the relative movement between the holding surface 50a and the object 11 stopped, the object 11 is washed with the liquid 88 ejected from the holding surface 50a (washing step S33). Figure 10 is a partial cross-sectional front view showing the processing device 4C in the washing step S33.

[0111] If the cleaning of the object 11 is insufficient in the liquid ejecting step S31 (see FIG. 8) and the moving step S32 (see FIG. 9), a cleaning step S33 is performed as necessary to additionally clean the second surface 11b side of the object 11. Specifically, the lifting of the holding unit 82 is interrupted, and the relative movement between the holding surface 50a and the object 11 is stopped, and the liquid 88 continues to be ejected from the holding surface 50a for a certain period of time. This allows the supply of the liquid 88 to the second surface 11b side of the object 11 to continue, and the cleaning time of the object 11 is extended.

[0112] The cleaning time for the object 11 in the cleaning step S33 (the supply time of the liquid 88) is set appropriately depending on the state of the object 11. For example, the cleaning time for the object 11 is from 5 seconds to 1 minute, and preferably from 10 seconds to 30 seconds. Furthermore, in the cleaning step S33, the flow rate of the liquid supplied from the liquid supply source 58B to the flow path 56, i.e., the flow rate of the liquid ejected from the holding surface 50a, may be set to be higher than in the liquid ejecting step S31 and the moving step S32. For example, the flow rate of the liquid in the cleaning step S33 is 1.2 times or more, preferably 1.5 times or more, and more preferably 2 times or more, of the flow rate of the liquid in the liquid ejecting step S31 and the moving step S32.

[0113] In the liquid ejecting step S31 (see FIG. 8), the moving step S32 (see FIG. 9), and the cleaning step S33 (see FIG. 10), the valve 60C may be opened together with the valve 60B. In this case, the liquid 88 supplied from the liquid supply source 58B and the gas supplied from the gas supply source 58C are mixed in the flow path 56, and a mixed fluid containing the liquid 88 and the gas is generated. Then, the mixed fluid is ejected from the holding surface 50a toward the object 11. As a result, the liquid 88 hits the object 11 with more force than when only the liquid 88 is ejected from the holding surface 50a, and the separation of the object 11 from the holding surface 50a and the cleaning of the object 11 are further promoted.

[0114] However, when the object 11 is relatively thin (for example, 100 mm or less in thickness), it is preferable to keep the valve 60C closed so that only the liquid 88 is ejected from the holding surface 50a, and not the gas. In this case, the liquid 88 ejected from the holding surface 50a is less likely to scatter, and it is possible to prevent the liquid 88 from adhering to the first surface 11a of the object 11. This makes it possible to prevent the liquid 88 adhering to the first surface 11a of the object 11 from interfering with the laser processing when the object 11 is processed again by the processing device 4A in a later step (see FIG. 2).

[0115] Furthermore, if the object 11 is sufficiently cleaned by the liquid 88 supplied to the object 11 in the liquid ejection step S31 and the movement step S32, the cleaning step S33 may be omitted. In this case, after the relative movement between the holding surface 50a and the object 11 is stopped in the above-mentioned movement step S32, the following liquid removal step S34 is immediately performed.

[0116] Next, the liquid 88 in contact with both the holding surface 50a and the target object 11 is removed (liquid removing step S34). Figure 11 is a partial cross-sectional front view showing the processing device 4C in the liquid removing step S34.

[0117] The processing device 4C includes a removal unit that removes the liquid 88 ejected from the holding surface 50a. In this embodiment, the removal unit is configured by the holding surface 50a, the flow path 56 connected to the holding surface 50a, and the suction source 58A and valve 60A connected to the flow path 56. When the object 11 is separated from the holding surface 50a, the controller 6C (see FIG. 1) of the processing device 4C controls the removal unit to cause the removal unit to remove the liquid 88 that is in contact with both the holding surface 50a and the object 11.

[0118] Specifically, with the lifting of the holding unit 82 stopped, the controller 6C outputs control signals to the valves 60A, 60B, and 60C, which close the valves 60B and 60C and open the valve 60A. This connects the holding surface 50a to the suction source 58A, and the suction force (negative pressure) of the suction source 58A acts on the holding surface 50a. As a result, the liquid 88 (see FIG. 10 ) in contact with the holding surface 50a and the object 11 is sucked into the holding surface 50a and removed from between the holding surface 50a and the object 11.

[0119] If the liquid 88 remaining between the holding surface 50a and the object 11 is left as it is, the surface tension of the liquid 88 acts on the object 11, causing the object 11 to be adsorbed to the holding surface 50a via the liquid 88. Therefore, when separating the object 11 from the holding surface 50a, it is necessary to carefully lift the object 11 with a strong force and separate it from the holding surface 50a, which hinders smooth transport of the object 11. Furthermore, if a strong external force is applied to the object 11, there is a risk that the object 11 will be deformed or damaged.

[0120] On the other hand, when the liquid removal step S34 is performed as in this embodiment, the liquid 88 that prevents the object 11 from separating from the holding surface 50a is removed from between the holding surface 50a and the object 11. This eliminates the surface tension of the liquid 88 acting on the object 11, making it possible to easily separate the object 11 from the holding surface 50a.

[0121] In the above, an example has been described in which the liquid 88 is sucked onto the holding surface 50a by the suction force of the suction source 58A, but there are no limitations on the configuration of the removal unit that removes the liquid 88 in the liquid removal step S34.

[0122] For example, the processing device 4C may include, as the removal unit, a nozzle (not shown) that sprays a gas such as air between the holding surface 50a and the object 11. In this case, the nozzle is controlled by the controller 6C (see FIG. 1 ), and the liquid 88 remaining between the holding surface 50a and the object 11 can be removed by injecting the gas from the nozzle onto the liquid 88. Alternatively, the valves 60A and 60B may be closed, and the valve 60C may be opened to eject the gas from the holding surface 50a, thereby blowing off and removing the liquid 88. In this case, the removal unit is configured by the holding surface 50a, the flow path 56 connected to the holding surface 50a, and the gas supply source 58C and the valve 60C connected to the flow path 56.

[0123] After the liquid 88 is removed in the liquid removal step S34, the target object 11 is transported from the holding surface 50a (transport step S35). Figure 12 is a partial cross-sectional front view showing the processing device 4C in the transport step S35.

[0124] In the transport step S35, the valve 60A is closed to release the suction force acting on the holding surface 50a, and then the holding unit 82 is moved by the moving unit 86 to transport the object 11. For example, the holding unit 82 is first raised along the Z-axis direction by the moving unit 86, thereby further separating the object 11 from the holding surface 50a. At this time, since no liquid 88 remains between the holding surface 50a and the object 11, the separation of the object 11 from the holding surface 50a is not hindered by the surface tension of the liquid 88.

[0125] Thereafter, the holding unit 82 is moved horizontally (in the XY plane direction) by the moving unit 86. As a result, the target object 11 is released from directly above the holding surface 50a (the area overlapping with the holding surface 50a in the Z-axis direction) and is carried out to the outside of the processing device 4C through a transfer port (not shown) of the processing device 4C.

[0126] In the series of processes from the holding step S1 to the transport step S35, foreign matter (machining debris, particles, etc.) present in the processing device 4C may adhere to the holding surface 50a or may enter the inside of the holding unit 50 from the holding surface 50a. In particular, in the step of applying suction force to the holding surface 50a (see FIGS. 6, 11, etc.), foreign matter is likely to adhere or enter. Therefore, after the target object 11 is separated from the holding surface 50a, the foreign matter may be removed from the holding unit 50 by ejecting a fluid from the holding surface 50a (foreign matter removal step S36).

[0127] 13 is a cross-sectional view showing the processing device 4C in the foreign matter removal step S36. For example, in the foreign matter removal step S36, valve 60A is closed, and valves 60B and 60C are opened. As a result, a mixed fluid containing liquid and gas is generated in the flow path 56, and the mixed fluid is ejected from the holding surface 50a. At this time, foreign matter present inside the holding unit 50 or on the holding surface 50a is carried away by the mixed fluid and is expelled from the holding surface 50a to the outside of the holding unit 50. As a result, the foreign matter is removed from the holding unit 50.

[0128] However, in the foreign matter removal step S36, the foreign matter may be removed by only the liquid by opening the valve 60B while the valves 60A and 60C are closed, or by only the gas by opening the valve 60C while the valves 60A and 60B are closed.

[0129] The timing of ejecting the fluid (liquid, gas, or mixed fluid) from the holding surface in the foreign matter removal step S36 can be set freely as long as it is after the target object 11 has separated from the holding surface 50a. However, it is particularly preferable to perform the foreign matter removal step S36 after the target object 11 has been released from directly above the holding surface 50a (the area overlapping with the holding surface 50a in the Z-axis direction) in the transfer step S35. This makes it difficult for foreign matter discharged from the holding surface 50a to adhere to the target object 11, even if it scatters upward. Furthermore, to reliably prevent foreign matter from adhering to the target object 11, the foreign matter removal step S36 may be performed after the target object 11 has been unloaded from the processing chamber (the space where grinding is performed) of the processing device 4C or after it has been unloaded from the processing device 4C.

[0130] As described above, the target object 11 is processed by the processing device 4C. Note that the steps from the holding step S1 to the foreign matter removal step S36 are realized by executing a program stored in the controller 6C (see FIG. 1) of the processing device 4C. Specifically, a program for operating each component of the processing device 4C so that the steps from the holding step S1 to the foreign matter removal step S36 are performed in order is stored in the storage unit (memory) of the controller 6C. Then, the controller 6C executes the program in response to an instruction from the host computer 14 (see FIG. 1). As a result, the steps from the holding step S1 to the foreign matter removal step S36 are automatically performed by the processing device 4C.

[0131] The object 11 processed by the processing device 4C is transported back to the processing device 4A by the transport system 8 (see FIG. 1). Then, the processing by the processing devices 4A, 4B, and 4C is repeated in order, so that a plurality of substrates 21 are sequentially separated from the object 11.

[0132] Note that the object 11 that has been ground by the processing device 4C may be polished before being transported to the processing device 4A. Specifically, the processing system 2 (FIG. 1) may include a processing device (polishing device) that polishes the object 11. In this case, after the first surface 11a of the object 11 is ground, the first surface 11a of the object 11 is subsequently polished. This allows the first surface 11a of the object 11 to be mirror-finished.

[0133] For example, a polishing apparatus includes a holding unit having a holding surface for holding the object 11, and a processing unit (polishing unit) for polishing the object 11 held by the holding unit. The polishing unit includes a spindle, and a disk-shaped polishing pad is attached to the tip of the spindle. The object 11 is held on the holding surface, and the object 11 is polished by bringing the polishing pad into contact with the object 11 while rotating the holding unit and the polishing pad.

[0134] As described above, in the object separation method, object processing method, and processing apparatus 4C according to the present embodiment, when the object 11 is separated from the holding surface 50a, the liquid 88 in contact with both the holding surface 50a and the object 11 is removed. This eliminates the surface tension of the liquid 88 acting on the object 11, making it possible to easily and appropriately separate the object 11 from the holding surface 50a.

[0135] In the above embodiment, an example has been described in which the holding step S1 to the separating step S3 are performed by the processing device 4C. However, the holding step S1 to the separating step S3 can also be applied to the processing of the object 11 by the processing devices 4A and 4B.

[0136] For example, the holding unit 20 of the processing device 4A (see FIG. 2) and the holding unit 40 of the processing device 4B (see FIGS. 3(A) and 3(B)) are configured similarly to the holding unit 50 of the processing device 4C (see FIG. 4). In addition, the holding units 20 and 40 are connected to a flow path 56, a suction source 58A, a liquid supply source 58B, a gas supply source 58C, and valves 60A, 60B, and 60C (see FIG. 4).

[0137] Processing devices 4A and 4B perform the holding step S1 to the separating step S3 in the same manner as processing device 4C. In this case, processing device 4A performs laser processing on object 11 in processing step S2 (see FIG. 2), but can perform holding step S1 and separating step S3 in the same manner as processing device 4C. Processing device 4B performs a process of separating substrate 21 from object 11 in processing step S2 (see FIGS. 3(A) and 3(B)), but can perform holding step S1 and separating step S3 in the same manner as processing device 4C. Furthermore, if processing system 2 (FIG. 1) includes another processing device (such as a polishing device), holding step S1 to separating step S3 may be performed in that processing device.

[0138] Furthermore, in this embodiment, an example has been described in which the object 11, which is an ingot, is processed by the processing system 2. However, the object processing method according to the present invention can also be applied to other objects and processing devices.

[0139] For example, in a device chip manufacturing process, device chips are manufactured by dividing a wafer made of a semiconductor material such as silicon, and a processing device (cutting device) that cuts an object with a circular cutting blade is used to divide the wafer.

[0140] The cutting device includes a holding unit having a holding surface for holding an object, and a processing unit (cutting unit) for cutting the object held by the holding unit. The cutting unit includes a spindle, the tip of which is fitted with an annular cutting blade. The wafer is held on the holding surface, and the cutting blade is rotated to cut into the wafer, cutting and dividing the wafer.

[0141] The holding step S1 to the separating step S3 can also be applied to the cutting of a wafer by a cutting device, which makes it possible to easily and appropriately separate the wafer after cutting from the holding surface of the holding unit.

[0142] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0143] 11 Object 11a 1st side (front) 11b 2nd side (back side) 11c Side (outer surface) 13 Modified section (deformed section) 15 Separation layer (modification layer) 21 Substrate (plate-like object) 21a 1st side (front) 21b 2nd side (back side) 2. Processing System 4A Processing equipment (laser processing equipment) 4B Processing equipment (separation equipment) 4C processing equipment (grinding equipment) 6A, 6B, 6C Controller (control unit, control section, control device) 8. Conveyor System 10. Transport unit (transport mechanism) 12A, 12B, 12C Transport unit (transport mechanism) 14 Host Computer 20 holding unit 20a Holding surface 22 Processing unit (laser irradiation unit) 24 Housing 26 Laser processing head 28 Laser Beam 30 Imaging unit 40 Holding Unit 40a Holding surface 42 Processing unit (separation unit) 44 Holding Unit 44a Holding surface 46 Support member 50 holding units 50a holding surface 50b flow path 50c pivot point 52 Frame (main body) 52a Top side 52b Recess 54 Retaining member 54a Suction surface 56 Flow path 58A Suction source 58B Liquid Source 58C Gas Source 60A, 60B, 60C valves 62 Pressure gauge 64 Mobile Units 66 Processing unit (grinding unit) 66a Rotation axis 68 Spindle 70 Wheel Mount 72 Grinding Wheel 74 Wheel base 76 Grinding Wheel 78 Mobile Unit 80 Transport Unit 82 Holding Unit 82a Holding surface 84 Suction source 86 Mobile Unit 88 liquid

Claims

1. A method for separating an object held on a holding surface from the holding surface, comprising: a liquid ejection step of ejecting liquid from the holding surface while the object is held by the holding surface; a moving step of moving the holding surface and the object relatively in directions away from each other after the liquid ejecting step, thereby separating the holding surface and the object while maintaining a state in which the liquid is in contact with both the holding surface and the object; a liquid removal step of removing the liquid in contact with both the holding surface and the object after the moving step.

2. 2. The method for separating objects according to claim 1, wherein the liquid removing step removes the liquid in contact with both the holding surface and the object by suction with the holding surface.

3. 3. The method for separating objects according to claim 1, wherein the object is cleaned with the liquid ejected from the holding surface in the liquid ejecting step or the moving step.

4. 3. The method for separating an object according to claim 1 or 2, further comprising a cleaning step, after the moving step and before the liquid removing step, of cleaning the object with the liquid ejected from the holding surface while stopping the relative movement between the holding surface and the object.

5. A method for processing an object, comprising: a holding step of holding the object with a holding surface; a processing step of processing the object held on the holding surface after the holding step; a liquid ejection step of ejecting a liquid from the holding surface while the object is held by the holding surface after the processing step; a moving step of moving the holding surface and the object relatively in directions away from each other after the liquid ejecting step, thereby separating the holding surface and the object while maintaining a state in which the liquid is in contact with both the holding surface and the object; a liquid removal step of removing the liquid in contact with both the holding surface and the object after the moving step.

6. a holding unit having a holding surface for holding an object; a processing unit that processes the object held on the holding surface; a liquid supply source that supplies the liquid to be ejected from the holding surface to the holding unit; a removal unit for removing the liquid ejected from the holding surface; a controller; The controller is capable of causing the removal unit to remove the liquid in contact with both the holding surface and the object.

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