Substrate processing system and substrate processing method

Abstract

After irradiation with laser light, the substrate is transported appropriately before separation. [Solution] A substrate processing system for processing substrates, comprising: a substrate holding unit having a holding surface for holding the substrate; a laser irradiation unit that irradiates the substrate held on the holding surface with laser light to form a separation surface which serves as a base point for separating the substrate; a separation unit that separates the substrate using the separation surface as a base point; and a substrate transport mechanism for transporting the substrate, wherein the substrate transport mechanism includes a plurality of transport arms, at least one of the plurality of transport arms has a plurality of guide pins arranged around the periphery of the substrate, and the substrate transport mechanism transports the substrate after irradiation with laser light, which is transported from the laser irradiation unit to the separation unit, by holding it with the transport arm having the guide pins.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing system and a substrate processing method.

Background Art

[0002] Patent Document 1 discloses that in a semiconductor substrate having a peeling oxide film and semiconductor elements formed on its surface, the semiconductor elements are transferred to a transfer destination substrate. The method described in Patent Document 1 includes a step of irradiating light from the back surface of the semiconductor substrate to locally heat the peeling oxide film, and a step of causing peeling in the peeling oxide film and / or at the interface between the peeling oxide film and the semiconductor substrate to transfer the semiconductor elements to the transfer destination substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology according to the present disclosure appropriately conveys a substrate after irradiation with laser light and before separation of the substrate.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a substrate processing system for processing a substrate, comprising: a substrate holding unit having a holding surface for holding the substrate; a laser irradiation unit for irradiating the substrate held on the holding surface with laser light to form a separation surface which serves as a base point for separating the substrate; a separation unit for separating the substrate with the separation surface as a base point; and a substrate transport mechanism for transporting the substrate, wherein the substrate transport mechanism includes a plurality of transport arms, at least one of the plurality of transport arms having a plurality of guide pins arranged around the periphery of the substrate, and the substrate transport mechanism transports the substrate after irradiation with laser light, which is transported from the laser irradiation unit to the separation unit, by holding it with the transport arm having the guide pins. [Effects of the Invention]

[0006] According to this disclosure, the substrate can be properly transported after irradiation with laser light and before separation of the substrate. [Brief explanation of the drawing]

[0007] [Figure 1] This is a side view showing a schematic configuration of the polymerized wafer to be processed. [Figure 2] This is a schematic plan view illustrating the general configuration of the wafer processing system. [Figure 3] This is a schematic perspective view showing the general configuration of a wafer transfer system. [Figure 4] This is a side view showing a schematic configuration of the laser irradiation device. [Figure 5] This is a plan view showing the schematic configuration of the laser irradiation device. [Figure 6] This is an explanatory diagram showing the eccentricity of the first and second wafers. [Figure 7] This is a side view showing the operation of the separation device. [Figure 8] This is an explanatory diagram showing how laser light is irradiated onto a laser absorption layer. [Figure 9] This is a flowchart showing the main steps in wafer processing. [Figure 10] This is an explanatory diagram showing an example of laser light irradiation on a laser absorption layer. [Figure 11] It is an explanatory diagram of an unirradiated region generated in the laser absorption layer. [Figure 12] It is an explanatory diagram showing an example of laser light irradiation on an unirradiated region. [Figure 13] It is an explanatory diagram showing another example of laser light irradiation on an unirradiated region. [Figure 14] It is an explanatory diagram showing another example of laser light irradiation on an unirradiated region. [Figure 15] It is an explanatory diagram showing the flow of the laser light irradiation operation on the laser absorption layer. [Figure 16] It is an explanatory diagram showing the state of transfer of the polymerized wafer between the chuck and the transfer arm. [Figure 17] It is an explanatory diagram showing the state of unloading from the separation device of the polymerized wafer. [Figure 18] It is a side view showing another configuration example of the laser irradiation device. [Figure 19] It is an explanatory diagram showing an example of an unirradiated region of laser light set on the polymerized wafer. [Figure 20] It is a plan view showing a configuration example of the laser irradiation device according to another embodiment. [Figure 21] It is an explanatory diagram simply showing the operating principle of the spectroscopic interferometer. [Figure 22] It is an explanatory diagram showing the state of inspection of the unbonded surface according to another embodiment.

Mode for Carrying Out the Invention

[0008] In the manufacturing process of a semiconductor device, in a polymerized wafer in which two semiconductor substrates (hereinafter referred to as "wafers") are joined, a device layer formed on the surface of the second wafer is transferred to the first wafer. The transfer of this device layer is performed, for example, using laser lift-off. That is, by irradiating laser light inside the polymerized wafer to reduce the bonding force between the first wafer and the second wafer, and then separating the second wafer from the first wafer, the device layer is transferred to the first wafer.

[0009] In a wafer processing system for performing this laser lift-off, the laser irradiation device that irradiates the polymer wafer with laser light and the separation device that separates the first wafer and the second wafer may be configured independently. Here, after the laser light is irradiated by the laser irradiation device, it is conceivable that the first wafer and the second wafer are separated unintentionally. In this case, if the horizontal misalignment between the first wafer and the second wafer is not detected and suppressed, the second wafer may fall from the first wafer due to inertial forces or the like associated with the transfer operation of the polymer wafer.

[0010] The technology according to the present disclosure has been made in view of the above circumstances, and appropriately detects whether or not the substrate has been separated after the irradiation of the laser light and before the separation of the substrate, based on the separation surface formed by the irradiation of the laser light. In the following description, the "separation" of the substrate to be detected refers to a state in which the second wafer moves horizontally with respect to the first wafer. More specifically, it includes a state in which the bonding strength between the second wafer and the first wafer becomes zero and the second wafer can move independently with respect to the first wafer, and a state in which the bonding strength has decreased and the second wafer is displaced horizontally with respect to the first wafer although the first wafer and the second wafer are still bonded.

[0011] Hereinafter, a wafer processing system as a substrate processing system according to the present embodiment and a wafer processing method as a substrate processing method will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0012] In the wafer processing system 1 described later according to this embodiment, processing is performed on a polymerized wafer T, which is a substrate formed by joining a first wafer W1 and a second wafer W2, as shown in Figure 1. Hereinafter, in the first wafer W1, the side that is joined to the second wafer W2 is referred to as the front surface W1a, and the side opposite to the front surface W1a is referred to as the back surface W1b. Similarly, in the second wafer W2, the side that is joined to the first wafer W1 is referred to as the front surface W2a, and the side opposite to the front surface W2a is referred to as the back surface W2b.

[0013] The first wafer W1, which serves as the lower substrate, is a semiconductor wafer such as a silicon substrate. In this embodiment, the first wafer W1 has a substantially disc shape. A device layer D1 and a surface film F1 are laminated on the surface W1a of the first wafer W1 in this order from the surface W1a side. The device layer D1 includes multiple devices. Examples of the surface film F1 include an oxide film (THOX film, SiO2 film, TEOS film), a SiC film, a SiCN film, or an adhesive.

[0014] The second wafer W2, which serves as the upper substrate, is also a semiconductor wafer, such as a silicon substrate. In this embodiment, the second wafer W2 has a substantially disc shape. On the surface W2a of the second wafer W2, a laser absorption layer P, a device layer D2, and a surface film F2 are stacked in this order from the surface W2a side. The laser absorption layer P absorbs laser light irradiated from the laser irradiation unit 110, as will be described later. For example, an oxide film (SiO2 film) is used for the laser absorption layer P, but it is not particularly limited as long as it absorbs laser light. The device layer D2 and the surface film F2 are the same as the device layer D1 and surface film F1 of the first wafer W1, respectively. The surface film F1 of the first wafer W1 and the surface film F2 of the second wafer W2 are then joined together. Note that the position of the laser absorption layer P is not limited to the above embodiment, and may be formed, for example, between the device layer D2 and the surface film F2.

[0015] As shown in Figure 2, the wafer processing system 1 has a configuration in which the loading / unloading block 10, the transport block 20, and the processing block 30 are connected as a single unit. The loading / unloading block 10 and the processing block 30 are provided around the transport block 20. Specifically, the loading / unloading block 10 is located on the negative Y-axis side of the transport block 20. The laser irradiation device 31 and the separation device 32, which will be described later, are located on the negative X-axis side of the transport block 20, the first cleaning device 33 and the second cleaning device 34, which will be described later, are located on the positive X-axis side of the transport block 20, and the inversion device 35, which will be described later, is located on the positive Y-axis side of the transport block 20.

[0016] The loading / unloading block 10 loads cassettes Ct, Cw1, and Cw2, each capable of accommodating multiple polymerized wafers T, multiple first wafers W1, and multiple second wafers W2, respectively, into and out of the loading / unloading block 10. The loading / unloading block 10 is provided with a cassette mounting table 11. In the illustrated example, the cassette mounting table 11 can accommodate multiple cassettes, for example, three cassettes Ct, Cw1, and Cw2, in a single row along the X-axis. The number of cassettes Ct, Cw1, and Cw2 placed on the cassette mounting table 11 is not limited to this embodiment and can be determined arbitrarily.

[0017] The transport block 20 is provided with a wafer transport device 22, which is a substrate transport mechanism configured to move freely along a transport path 21 extending in the Y-axis direction. The wafer transport device 22 has a plurality of transport arms 23a to 23c (in the following description, these may be collectively referred to simply as "transport arms 23") for holding and transporting the polymerized wafer T, the first wafer W1, or the second wafer W2. Each transport arm 23 has a suction part 24 (see Figure 3) on its holding surface for adsorbing and holding the polymerized wafer T, the first wafer W1, or the second wafer W2. Each transport arm 23 is configured to move freely in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. The wafer transport device 22 is configured to transport the polymerized wafer T, the first wafer W1, and the second wafer W2 to the cassettes Ct, Cw1, and Cw2 on the cassette mounting table 11, the laser irradiation device 31, the separation device 32, the first cleaning device 33, the second cleaning device 34, and the inversion device 35.

[0018] As shown in Figure 3, the three transport arms 23a to 23c are stacked in this order from top to bottom. Each of the transport arms 23a to 23c is configured to rotate independently around a vertical axis. Multiple guide pins, for example three, are provided on the wafer holding surface of at least one of the three transport arms 23a to 23c (in the illustrated example, the middle transport arm 23b). The guide pins 25 are arranged to surround the polymerized wafer T when it is held by the transport arm 23b. The guide pins 25 then prevent the second wafer W2 from falling from the first wafer W1 due to the inertial force etc. associated with the transport of the polymerized wafer T by the wafer transport device 22, as will be described later. Furthermore, as shown in Figure 3, at least one of the multiple transport arms 23a to 23c (the uppermost transport arm 23a in the illustrated example) has a suction part 24, i.e., a holding surface on its lower side, for adsorbing and holding the polymerized wafer T, the first wafer W1, or the second wafer W2. The transport arm 23a having the suction part 24 on its lower side then adsorbs and holds the second wafer W2 (upper substrate) from above when it is unloaded from the separation device 32 described later. Note that the configuration of the transport arm 23 is not limited to this embodiment and can be any configuration.

[0019] The processing block 30 includes a laser irradiation device 31, a separation device 32, a first cleaning device 33, a second cleaning device 34, and an inversion device 35. However, the number and arrangement of the laser irradiation device 31, separation device 32, first cleaning device 33, second cleaning device 34, and inversion device 35 are not limited to these.

[0020] The laser irradiation device 31 irradiates the inside of the polymerized wafer T, more specifically the laser absorption layer P of the second wafer W2, with laser light to reduce the bonding strength at the interface between the second wafer W2 and the laser absorption layer P. This interface within the polymerized wafer T where the bonding strength has been reduced (in this embodiment, the interface between the second wafer W2 and the laser absorption layer P) may be referred to as the "separation surface" in the technology of this disclosure.

[0021] As shown in Figures 4 and 5, a transfer position A1 and a processing position A2 are set inside the laser irradiation device 31. Transfer position A1 is a position where the wafer can be transferred between the transport arm 23 and the chuck 100 (described later), and where the outer edge of the polymerized wafer T can be imaged by the imaging mechanism 120 (described later). Processing position A2 is a position where laser light can be irradiated onto the polymerized wafer T (laser absorption layer P) from the laser irradiation unit 110 (described later).

[0022] The laser irradiation device 31 has a chuck 100 as a substrate holder that holds the polymerized wafer T on its upper surface. The chuck 100 has a wafer holding surface on its upper surface and holds the entire surface W1b of the back surface W1b of the first wafer W1 by suction, or a part of the radially inner surface W1b. The chuck 100 is, for example, an electrostatic chuck (ESC) or a vacuum chuck.

[0023] The chuck 100 is also provided with a lifting pin 100a (see Figure 16) for supporting and raising / lowering the polymerized wafer T from below. The lifting pin 100a is inserted through a through hole (see Figure 16) formed through the chuck 100 and is configured to move up and down freely.

[0024] Furthermore, the chuck 100 is provided with multiple wafer fall prevention pins 101, such as three, that surround the polymerized wafer T on the holding surface along the circumferential direction, serving as substrate fall prevention pins. The wafer fall prevention pin 101 prevents the second wafer W2 from falling from the first wafer W1 if it unintentionally separates from the first wafer W1 during or after laser irradiation due to, for example, centrifugal force associated with the rotation of the chuck 100 or inertial force associated with movement.

[0025] The arrangement of the wafer fall prevention pins 101 is not particularly limited. For example, in this embodiment, the wafer fall prevention pins 101 are configured to be rotatable together with the chuck 100 by a rotation mechanism 104 described later, and are configured to be movable in the Y-axis direction together with the chuck 100 by a drive mechanism 105 described later, and are further configured to be able to move up and down in the Z-axis direction together with the lifting pins 100a described above.

[0026] The chuck 100 is supported by the slider table 103 via an air bearing 102. A rotating mechanism 104 is provided on the underside of the slider table 103. The rotating mechanism 104 incorporates, for example, a motor as a drive source. The chuck 100 is configured to rotate freely around the θ axis (vertical axis) via the air bearing 102 through the rotating mechanism 104. The slider table 103 is configured to move between the above-mentioned transfer position A1 and processing position A2 along a rail 107 that extends in the Y-axis direction and is provided on the base 106, by a drive mechanism 105 provided on its underside. The drive source for the drive mechanism 105 is not particularly limited, but for example, a linear motor can be used.

[0027] A laser irradiation unit 110 is provided above the chuck 100 at processing position A2. The laser irradiation unit 110 includes a laser head 111, an optical system 112, and a lens 113.

[0028] The laser head 111 has a laser oscillator (not shown) that emits laser light in a pulsed manner. This laser light is a so-called pulsed laser. In this embodiment, the laser light is CO2 laser light, and the wavelength of the CO2 laser light is, for example, 8.9 μm to 11 μm. The laser head 111 may also have other equipment besides the laser oscillator, such as an amplifier.

[0029] The optical system 112 includes optical elements (not shown) that control the intensity and position of the laser beam, and an attenuator (not shown) that reduces the laser beam to adjust the output. The optical system 112 may also be configured to control the branching of the laser beam.

[0030] The lens 113 irradiates the polymerized wafer T held in the chuck 100 with laser light. The laser light emitted from the laser irradiation unit 110 passes through the second wafer W2 and irradiates the laser absorption layer P. The lens 113 may be configured to move up and down by a lifting mechanism (not shown).

[0031] Furthermore, an imaging mechanism 120, which serves as a detection mechanism, is provided above the chuck 100 at the transfer position A1. The imaging mechanism 120 includes, for example, one or more cameras 121 selected from macro cameras, micro cameras, etc., and a calculation unit 122. The imaging mechanism 120 may be configured to be movable in the Y-axis and Z-axis directions by means of a lifting mechanism (not shown) and a moving mechanism (not shown).

[0032] The camera 121, acting as the acquisition unit, images the outer edge of the polymerized wafer T held in the chuck 100. The camera 121 is equipped with, for example, a coaxial lens, emits infrared light (IR), and also receives reflected light from the object. By imaging the outer edge of the polymerized wafer T in this way, the camera 121 acquires positional information of the polymerized wafer T (at least the second wafer W2) on the chuck 100. The calculation unit 122, acting as a determination unit, detects the eccentricity of the second wafer W2 relative to the first wafer W1 (the amount of deviation in the horizontal direction (direction along the separation plane): see Figure 6) based on the position information of at least the second wafer W2 obtained from the image data captured by the camera 121. Details of the method for detecting the eccentricity of the first wafer W1 and the second wafer W2 by the imaging mechanism 120 will be described later. In Figure 6, in order to clearly show the eccentricity of the first wafer W1 and the second wafer W2, the chuck 100 does not have the wafer fall prevention pin 101 described above, and the eccentricity occurring in the first wafer W1 and the second wafer W2 is shown to be larger than it actually is.

[0033] The calculation unit 122 may be provided independently of the imaging mechanism 120 as described above, but it may also be included in the control device 40, which will be described later. Furthermore, the imaging results from the camera 121 and the eccentricity calculated by the calculation unit 122 may be output to the control device 40. In other words, the control device 40 may function as an acquisition unit and a determination unit related to the technology of this disclosure.

[0034] In this embodiment, the description will be given as an example where the "acquisition unit" of the detection mechanism according to the technology of this disclosure is a "camera 121" that images at least the outer edge of the second wafer W2. However, the configuration of the acquisition unit is not limited to this, as long as it can acquire at least the position of the second wafer W2 on the chuck 100. Specifically, for example, the "acquisition unit" of the detection mechanism according to the technology of this disclosure may be a length measuring sensor (displacement meter) that acquires position information of the second wafer W2 by measuring at least the distance to the second wafer W2.

[0035] Furthermore, in this embodiment, the description will be given as an example in which the acquisition unit (camera 121 or length measuring sensor) relating to the technology of this disclosure is positioned above the chuck 100 at the transfer position A1. However, the acquisition unit may be positioned to the side of the chuck 100 as long as it is possible to acquire the position of at least the second wafer W2 on the chuck 100.

[0036] A transport pad 130 is further provided above the chuck 100 at the transfer position A1. The transport pad 130 is configured to be able to move up and down by a lifting mechanism (not shown). The transport pad 130 also has a suction surface on its lower side for adsorbing and holding the first wafer W1. Then, when the imaging mechanism 120 detects that eccentricity has occurred between the first wafer W1 and the second wafer W2 in the polymerized wafer T after irradiation of the laser absorption layer P with laser light, the transport pad 130 transports the second wafer W2 between the chuck 100 and the transport arm 23. Details of the operation of the transport pad 130 will be described later.

[0037] The separation device 32 separates the second wafer W2 from the first wafer W1, using the interface between the second wafer W2, which serves as the separation surface, and the laser absorption layer P, where the bonding strength has been reduced by the laser irradiation device 31, as the starting point.

[0038] In one example, as shown in Figure 7, the separation device 32 includes a suction chuck 200 that holds the back surface W1b of the first wafer W1 from below, and a suction pad 210 that holds the back surface W2b of the second wafer W2 from above. The suction chuck 200 is also provided with a lifting pin 200a for supporting and raising / lowering the first wafer W1 from below. The lifting pin 200a is inserted through a through hole formed in the suction chuck 200 and is configured to be able to move up and down. In the separation device 32, as shown in Figure 7, with the suction pad 210 holding the second wafer W2 by suction, the suction pad 210 is raised to separate the second wafer W2 from the laser absorption layer P.

[0039] The configuration of the separation device 32 is not limited to this, and any configuration is possible as long as the second wafer W2 can be separated from the first wafer W1.

[0040] The first cleaning device 33 cleans the surface W1a side of the first wafer W1 separated by the separation device 32. For example, a brush is brought into contact with the laser absorption layer P on the surface W1a side of the first wafer W1 to clean the laser absorption layer P. A pressurized cleaning solution may be used to clean the first wafer W1. The first cleaning device 33 may also have a configuration to clean the back surface W1b of the first wafer W1 in addition to the surface W1a side.

[0041] The second cleaning device 34 cleans the surface W2a side of the second wafer W2 that was separated by the separation device 32. For example, a brush is brought into contact with the surface W2a of the second wafer W2 to clean the surface W2a. Pressurized cleaning solution may be used to clean the second wafer W2. The second cleaning device 34 may also be configured to clean the back surface W2b of the second wafer W2 in addition to the surface W2a side.

[0042] In this embodiment, as described above, the first cleaning device 33 for cleaning the first wafer W1 and the second cleaning device 34 for cleaning the second wafer W2 are arranged independently. However, the cleaning of the first wafer W1 and the second wafer W2 may be performed using the same cleaning device.

[0043] The inversion device 35 inverts the upper and lower surfaces of the second wafer W2 after it has been separated by the separation device 32. That is, it inverts the front and back surfaces of the second wafer W2 so that the surface W2a, which is the side separated from the first wafer W1, faces upwards. The configuration of the inversion device 35 is not particularly limited.

[0044] The wafer processing system 1 described above is provided with a control device 40 as a control mechanism. The control device 40 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the processing of the polymerized wafer T in the wafer processing system 1. The program storage unit also stores a program that controls the operation of the various processing devices and transport devices and other drive systems to realize the wafer processing described later in the wafer processing system 1. The above program may have been recorded on a storage medium H that is readable by the computer and installed from the storage medium H to the control device 40. The storage medium H may be temporary or permanent.

[0045] Next, a wafer processing procedure performed using the wafer processing system 1 configured as described above will be explained. In this embodiment, the first wafer W1 and the second wafer W2 are bonded together in an external bonding device (not shown) to the wafer processing system 1 to form a polymerized wafer T in advance.

[0046] First, a cassette Ct containing multiple polymerized wafers T is placed on the cassette mounting table 11 of the loading / unloading block 10.

[0047] Next, the polymerized wafer T in the cassette Ct is removed by the transport arm 23c of the wafer transport device 22 and transported to the laser irradiation device 31. In the laser irradiation device 31, as shown in Figure 8, laser light L (CO2 laser light) is pulsed from the laser irradiation unit 110 onto the laser absorption layer P, and more specifically, onto the interface between the laser absorption layer P and the second wafer W2, thereby reducing the bonding strength between the laser absorption layer P and the second wafer W2.

[0048] A specific wafer processing method using the laser irradiation device 31 will be described.

[0049] In the laser irradiation apparatus 31, the polymerized wafer T is transferred from the transport arm 23c to the chuck 100 located at the transfer position A1, and is held by suction on the chuck 100 (step St1 in Figure 9).

[0050] Next, the outer edges of the polymerized wafers T (first wafer W1 and second wafer W2) held by suction on the chuck 100 are imaged using the imaging mechanism 120 (step St2 in Figure 9). Specifically, while the chuck 100 is rotated, the camera 121 captures images of the outer edges of the polymerized wafers T in a 360-degree circumferential direction, thereby acquiring positional information of the polymerized wafers T (first wafer W1 and second wafer W2) on the chuck 100. The imaging results from the camera 121 are output to the calculation unit 122.

[0051] The calculation unit 122 calculates the eccentricity of the first wafer W1 and the second wafer W2 on the chuck 100 before irradiation with the laser light L (see Figure 6) based on the positional information of the first wafer W1 and the second wafer W2 obtained from the imaging results by the camera 121. The calculated eccentricity of the first wafer W1 and the second wafer W2 before irradiation with the laser light L is used to determine whether a displacement has occurred between the first wafer W1 and the second wafer W2 after irradiation with the laser light L, that is, whether the second wafer W2 has separated from the first wafer W1, by comparing it with the eccentricity of the first wafer W1 and the second wafer W2 after irradiation with the laser light L, as described later. The calculated eccentricity of the first wafer W1 and the second wafer W2 before irradiation with the laser light L may be output to the control device 40.

[0052] Furthermore, the calculation unit 122 may calculate the eccentricity (horizontal displacement) between the rotation center of the chuck 100 and the center of the polymerized wafer T (first wafer W1 and / or second wafer W2) based on the imaging results from the camera 121. If eccentricity is observed between the rotation center of the chuck 100 and the center of the polymerized wafer T, it is desirable to perform eccentricity correction control, taking into account the eccentricity calculated when irradiating the laser beam L onto the laser absorption layer P described later. The calculated eccentricity between the rotation center of the chuck 100 and the center of the polymerized wafer T (second wafer W2) may be output to the control device 40.

[0053] Furthermore, the control device 40 acquires the positions of the central region R1 and the outer peripheral region R2 (see Figure 10) of the chuck 100, which are set in advance, and sets these central region R1 and outer peripheral region R2 relative to the polymerized wafer T, which is the target of laser light L irradiation, based on the imaging results from the camera 121. More specifically, within the plane of the polymerized wafer T held by the chuck 100, regions corresponding to the central region R1 and outer peripheral region R2, respectively (regions that overlap with the central region R1 and outer peripheral region R2, respectively, in a plan view) are set. The positions of the central region R1 and outer peripheral region R2 of the chuck 100 may be set relative to the rotation center of the chuck 100 and acquired from those that have been output in advance to the control device 40.

[0054] Next, the drive mechanism 105 moves the chuck 100 to the processing position A2. Next, the laser irradiation unit 110 starts irradiating the laser absorption layer P, and more specifically, the interface between the laser absorption layer P and the second wafer W2, with laser light L (CO2 laser light).

[0055] In this embodiment, the laser irradiation device 31 rotates the polymerized wafer T held in the chuck 100 by the rotation mechanism 104, and while moving the polymerized wafer T in the Y-axis direction by the drive mechanism 105, the laser beam L is irradiated in a pulsed manner. As a result, the irradiation position of the laser beam L moves radially from the outside to the inside with respect to the laser absorption layer P, and consequently, the laser beam L is irradiated in a spiral shape in a plan view, as shown in Figure 10. In this process, if we try to maintain a constant interval between irradiations of the laser beam L in order to uniformly separate the second wafer W2 and the laser absorption layer P across the wafer surface, the peripheral speed of the polymerized wafer T at the irradiation position of the laser beam L decreases as the irradiation position of the laser beam L moves from the radial outside to the inside, more specifically as it approaches the rotation center of the chuck 100. Therefore, it becomes necessary to increase the rotation speed of the polymerized wafer T. However, if the rotation speed of the polymerized wafer T is increased in this way, there is a risk that the second wafer W2 may unexpectedly separate from the first wafer W1 due to the centrifugal force accompanying the rotation of the polymerized wafer T, even during the irradiation of the laser beam L. Therefore, in this embodiment, when irradiating the outer peripheral region R2 (see Figure 10) of the chuck 100 where the peripheral speed of the polymerized wafer T is relatively high with the laser beam L, the polymerized wafer T is rotated, and when irradiating the central region R1 (see Figure 10) of the chuck 100 where the peripheral speed of the polymerized wafer T is slower, the rotation of the polymerized wafer T is stopped while the laser beam L is scanned.

[0056] The central region R1 of the chuck 100, which scans the laser beam L, is a circular region having a desired diameter length relative to the rotation center of the chuck 100, and is set in advance prior to wafer processing in the laser irradiation device 31, as described above. The diameter length of the central region R1 is, for example, the radial position where the relative rotation speed of the chuck 100 with respect to the lens 113 of the laser irradiation unit 110 reaches its upper limit; in other words, it is the limit position where the laser beam L does not overlap. The diameter length of the central region R1 is approximately 10 mm as an example. Furthermore, the outer peripheral region R2, which rotates the chuck 100 when the laser beam L is irradiated, is set to be radially outward from the central region R1.

[0057] When irradiating the laser absorption layer P with laser light L, first, the polymerized wafer T (laser absorption layer P) in the region corresponding to the outer peripheral region R2 is irradiated with laser light L (step St3 in Figure 9). At this time, the laser irradiation device 31 rotates the chuck 100 (polymerized wafer T) and moves the chuck 100 (polymerized wafer T) in the Y-axis direction while irradiating the laser light L in a pulsed manner from the laser irradiation unit 110 as described above, thereby irradiating the laser light L in a spiral shape from the radial outside to the inside, as shown in Figure 10. At this time, the laser light L is irradiated from the back surface W2b side (opposite side from the holding surface) of the second wafer W2, as shown in Figure 8, passes through the second wafer W2, and is absorbed by the laser absorption layer P. As a result, the bonding strength at the interface between the laser absorption layer P and the second wafer W2 decreases. In this embodiment, "decreased bonding strength" refers to a state in which the bonding strength has decreased at least compared to before irradiation with the laser light L. More specifically, it refers to a bonding strength such that the second wafer W2 is not shifted horizontally (separated) by the centrifugal force accompanying the rotation of the chuck 100 or the inertial force accompanying its movement, and that the second wafer W2 can be properly separated from the first wafer W1 by the separation device 32 described later.

[0058] Once the irradiation of the outer peripheral region R2 and the corresponding region with laser light L (reduction of bonding strength between the second wafer W2 and the laser absorption layer P) is complete, the next step is to irradiate the polymerized wafer T (laser absorption layer P) in the region corresponding to the central region R1 with laser light L (step St4 in Figure 9). When irradiating the region corresponding to the central region R1 with laser light L, the rotation of the chuck 100 is stopped. Then, while irradiating the laser light L in a pulsed manner from the laser irradiation unit 110, the scanning of the irradiation position of the laser light L in the X-axis direction and the movement of the chuck 100 (polymerized wafer T) in the Y-axis direction by the drive mechanism 105 are repeatedly performed alternately (see Figure 10).

[0059] Furthermore, in order to improve the throughput of wafer processing, the laser beam L may be split by the optical system 112 described above, and the laser beam L may be irradiated simultaneously at multiple points on the laser absorption layer P. Furthermore, in the example shown in Figure 10, when irradiating the central region R1 and the corresponding region with laser light L, the irradiation position was repeatedly scanned in the X-axis direction and moved in the Y-axis direction alternately. However, similar to the outer peripheral region R2 and the corresponding region, the laser light L may be irradiated in a spiral pattern. Alternatively, although not shown in the figure, the laser light L may be irradiated in a ring-like pattern concentrically with the polymerized wafer T (laser absorption layer P).

[0060] Here, as described above, when the laser beam L is irradiated in a spiral manner onto the laser absorption layer P in the outer peripheral region R2, an unirradiated area of ​​up to approximately one full rotation in the circumferential direction occurs near the boundary between the outer peripheral region R2 and the central region R1, as shown in Figure 11. When such an unirradiated area of ​​laser beam L occurs within the plane of the laser absorption layer P, there is a risk that the separation device 32 may not be able to properly separate the laser absorption layer P and the second wafer W2 in the portion corresponding to the unirradiated area.

[0061] Therefore, in the laser irradiation device 31 according to this embodiment, prior to switching the irradiation of the laser beam L from the outer peripheral region R2 to the central region R1, in other words, prior to stopping the rotation of the chuck 100 for irradiation of the laser beam L to the central region R1, the laser beam L is irradiated concentrically onto the laser absorption layer P so as to surround the central region R1, as shown in Figure 12. More specifically, when irradiating the outer peripheral region R2 with laser light L, the chuck 100 (polymerized wafer T) was rotated and moved in the Y-axis direction as described above, thereby irradiating the laser light L in a spiral pattern. However, near the boundary between the outer peripheral region R2 and the central region R1, the rotation of the chuck 100 (polymerized wafer T) was continued, while the movement in the Y-axis direction was stopped, thereby irradiating the laser absorption layer P with laser light L in a concentric pattern.

[0062] Furthermore, the concentric irradiation of the laser beam L onto the laser absorption layer P may be performed only once around the central region R1, as shown in Figure 12. Alternatively, as shown in Figure 13, the laser beam L may be pulsed from the laser irradiation unit 110, and the rotation of the chuck 100 (polymerized wafer T) by the rotation mechanism 104 and the movement of the chuck 100 (polymerized wafer T) in the Y-axis direction by the drive mechanism 105 may be repeatedly performed alternately, thereby irradiating the laser beam L in a concentric pattern multiple times in the radial direction. Furthermore, if the laser absorption layer P and the second wafer W2 can be appropriately separated, the irradiation of the laser beam L may be stopped after one or fewer rotations in the circumferential direction (270 degrees in the example of Figure 14) in order to suppress the influence on the device layer due to overlapping irradiation positions of the laser beam L, as shown in Figure 14.

[0063] Furthermore, by irradiating the laser beam L concentrically near the boundary between the outer region R2 and the central region R1 in this manner, the size of the unirradiated area in the laser absorption layer P can be reduced, thereby enabling more appropriate separation of the laser absorption layer P and the second wafer W2.

[0064] In Figures 12, 13, and 14, the helical machining portion in the outer region R2 is shown with a dashed line and the concentric circular machining portion with a dashed-dotted line for clarity; however, in reality, the irradiation interval of the laser beam L is constant between the helical machining portion and the concentric circular machining portion.

[0065] In the example shown in Figure 10, the laser beam L is depicted as if it were irradiated in one go from the radially outer side (near the outer edge of the laser absorption layer P) to the radially inner side (the boundary of the central region R1) in the outer peripheral region R2. However, in reality, even during the irradiation of the laser beam L to this outer peripheral region R2, the conditions related to the irradiation of the laser beam L, such as the frequency of the laser beam L, the rotational speed of the chuck 100, and the horizontal movement speed of the chuck 100, may be changed in order to control the interval between irradiations to a constant level. Alternatively, multiple regions with different conditions for irradiation by the laser light L may be generated within the outer region R2. In this case, as shown in the comparative example in Figure 15, if the rotation of the chuck 100 is stopped and restarted each time the irradiation conditions of the laser beam L are changed, in other words, if the irradiation conditions of the laser beam L are changed while the chuck 100 is stopped, the time required for acceleration and deceleration related to stopping and restarting the rotation increases the time required for laser processing.

[0066] Therefore, in the laser irradiation apparatus 31 according to this embodiment, when changing the irradiation conditions of the laser beam L to the outer peripheral region R2 during irradiation, it is desirable to stop only the irradiation of the laser beam L to the polymerized wafer T and the horizontal movement of the chuck 100, while continuing the rotation of the chuck 100. By continuing the rotation of the chuck 100 when changing the irradiation conditions of the laser beam L, the time required for accelerating and decelerating the rotation speed of the chuck 100 can be reduced, as shown in the present example in Figure 15, thereby shortening the time required for laser processing.

[0067] Furthermore, when the irradiation conditions of the laser beam L are changed by continuing to rotate the chuck 100 in this manner, the position where the irradiation of the laser beam L is restarted after the change in irradiation conditions may be the same as the position where the irradiation of the laser beam L ended before the change in irradiation conditions, or it may be a different position as long as the irradiation positions of the laser beam L do not overlap. When the restart position and the end position of laser beam L irradiation are to be the same, after changing the irradiation conditions for laser beam L, irradiation of laser beam L is not restarted until the rotation of the chuck 100 brings the end position of irradiation directly below the irradiation point of laser beam L. In this case, the interval at which laser beam L is irradiated can be controlled to be constant across the entire surface of the laser absorption layer P, and the separation of the second wafer W2 and the laser absorption layer P can be uniformly controlled within the wafer surface. On the other hand, if the resumption and termination positions of laser beam L are different, after changing the irradiation conditions for laser beam L, the irradiation of laser beam L should be promptly resumed at a position where the irradiation positions of laser beam L do not overlap. In this case, the waiting time until the start of laser beam L irradiation can be reduced, further shortening the time required for laser processing.

[0068] When the central region R1 and the outer peripheral region R2 are irradiated with laser light L, and the bonding strength between the second wafer W2 and the laser absorption layer P is reduced across the entire surface, the drive mechanism 105 then moves the chuck 100 (polymerized wafer T) to the transfer position A1.

[0069] Next, at the transfer position A1, the outer edge of the polymerized wafer T held by the chuck 100 is imaged using the imaging mechanism 120 (step St5 in Figure 9). Specifically, while the chuck 100 is rotated, the camera 121 captures images of the outer edge of the polymerized wafer T in a 360-degree circumferential direction, thereby acquiring positional information of the polymerized wafer T (first wafer W1 and second wafer W2) on the chuck 100. The imaging results from the camera 121 are output to the calculation unit 122. The calculation unit 122 calculates the eccentricity of the first wafer W1 and the second wafer W2 after irradiation with laser light L (see Figure 6) based on the position information obtained from the imaging results by the camera 121. The calculated eccentricity of the first wafer W1 and the second wafer W2 after irradiation with laser light L may be output to the control device 40.

[0070] The control device 40 calculates the difference between the eccentricity of the first wafer W1 and the second wafer W2 before irradiation with the output laser light L and the eccentricity of the first wafer W1 and the second wafer W2 after irradiation with the laser light L, and determines whether or not the second wafer W2 has been separated from the first wafer W1 based on this difference (step St6 in Figure 9).

[0071] In the wafer processing system 1 according to this embodiment, the polymerized wafer T in which the bonding strength between the second wafer W2 and the laser absorption layer P has decreased is separated from the first wafer W1 and the second wafer W2 in a separation device 32 provided outside the laser irradiation device 31. However, as described above, if the bonding strength between the second wafer W2 and the laser absorption layer P is reduced by irradiation with laser light L, the second wafer W2 may separate from the laser absorption layer P (first wafer W1) before being transported to the separation device 32 due to the inertial force when it is moved to the transfer position A1 by the drive mechanism 105 and the centrifugal force associated with the rotation of the chuck 100. Furthermore, if the second wafer W2 separates in this manner before being transported to the separation device 32, there is a risk that the polymerized wafer T may not be properly transported to the separation device 32, and there is also a risk that the second wafer W2 may fall within the system, causing problems.

[0072] In this regard, in the laser irradiation apparatus 31 according to this embodiment, in step St6, it is possible to determine whether the second wafer W2 has separated from the first wafer W1 prior to transporting the polymerized wafer T to the separation apparatus 32. This suppresses the wafer transport apparatus 22 from attempting to transport the polymerized wafer T, in which the second wafer W2 has separated from the first wafer W1, to the separation apparatus 32, thereby reducing concerns about dropping the second wafer W2 within the system.

[0073] Furthermore, in this embodiment, as shown in Figures 4 and 5, a plurality of wafer fall prevention pins 101, at least three of them, are provided around the polymerized wafer T held in the chuck 100. This prevents the second wafer W2 from falling into the laser irradiation device 31 even if the second wafer W2 separates from the first wafer W1 after irradiation of the laser absorption layer P with laser light L.

[0074] In step St6, if it is determined that the polymerized wafer T has separated from the first wafer W1, the transport pad 130 first holds the back surface W2b of the second wafer W2 by adsorption, and then the transport pad 130 is raised to move the second wafer W2 away from the first wafer W1 (step St7 in Figure 9). Next, the first wafer W1 on the chuck 100 is transferred to the transport arm 23c of the wafer transport device 22, and the first wafer W1 is discharged from the laser irradiation device 31 (step St8 in Figure 9). At this time, if eccentricity (positional misalignment) of the first wafer W1 relative to the chuck 100 is detected in step St2, the insertion position of the transport arm 23c may be adjusted according to the amount of eccentricity. Next, the second wafer W2, which is held by the transport pad 130, is transferred to the transport arm 23a of the wafer transport device 22, and the second wafer W2 is removed from the laser irradiation device 31 (step St9 in Figure 9). At this time, it is desirable to use a transport arm 23a that holds the second wafer W2 by adsorption from above in order to hold the back surface W2b of the second wafer W2 (the side opposite to the side separated from the first wafer W1). Alternatively, the second wafer W2 may be transferred to the transport arm 23a via the chuck 100.

[0075] The first wafer W1, removed from the laser irradiation device 31, is then transported by the wafer transport device 22 to cassette Cw1 on the cassette mounting table 11. The second wafer W2, removed from the laser irradiation device 31, is inverted in the inversion device 35 so that the side separated from the first wafer W1 faces upwards, and then transported by the wafer transport device 22 to cassette Cw2 on the cassette mounting table 11. At this time, the first wafer W1 and the second wafer W2 may be transported to cassettes Cw1 and Cw2 on the cassette mounting table 11 after their separated sides, surface W1a and surface W2a, are cleaned in the first cleaning device 33 and the second cleaning device 34, respectively.

[0076] On the other hand, in step St6, if it is determined that the second wafer W2 has not separated from the first wafer W1, the polymerized wafer T is transferred from the chuck 100 to the transfer arm 23b of the wafer transfer device 22 and discharged from the laser irradiation device 31 (step St10 in Figure 9).

[0077] Here, in step St6 described above, even though the second wafer W2 is actually separated from the first wafer W1, if the separation of the second wafer W2 is not properly detected, there is a risk that the second wafer W2 may fall within the system due to the impact applied to the polymerized wafer T when it is transferred from the chuck 100 to the transport arm 23, or due to the inertial force during transport by the transport arm 23.

[0078] In this regard, in the laser irradiation apparatus 31 according to this embodiment, as described above, the wafer fall prevention pin 101, which is arranged to surround the polymerized wafer T held in the chuck 100, is configured to be able to move up and down in the Z-axis direction integrally with the lifting pin 100a. The transfer of the polymerized wafer T from the chuck 100 to the transport arm 23b is performed by supporting the polymerized wafer T from below with the lifting pin 100a, raising it, then inserting the transport arm 23b between the holding surface of the chuck 100 and the lower surface of the polymerized wafer T (the back surface W1b of the first wafer W1), and then lowering the polymerized wafer T with the lifting pin 100a. At this time, as shown in Figure 16, by raising and lowering the wafer fall prevention pin 101 together with the lifting pin 100a, the wafer fall prevention pin 101 can surround the polymerized wafer T even when it is being raised by the lifting pin 100a, thereby suppressing the fall of the second wafer W2 when it is being transferred from the chuck 100 to the transport arm 23b.

[0079] Furthermore, in the wafer processing system 1 according to this embodiment, when transporting the polymerized wafer T after irradiation with laser light L from the laser irradiation device 31 to the separation device 32, a transport arm 23b having guide pins 25 arranged on the holding surface to surround the polymerized wafer T is used. This prevents the second wafer W2 from falling due to inertial force during the transport of the polymerized wafer T from the laser irradiation device 31 to the separation device 32, even when the second wafer W2 is separated from the first wafer W1.

[0080] The polymerized wafer T, removed from the laser irradiation device 31, is then transported to the separation device 32 by the wafer transport device 22. In the separation device 32, as shown in Figure 7, the back surface W1b of the first wafer W1 is held by the suction chuck 200, and the back surface W2b of the second wafer W2 is held by the suction pad 210. Then, with the suction pad 210 holding the second wafer W2, the suction pad 210 is raised to separate the first wafer W1 and the second wafer W2. At this time, as described above, the bonding strength at the interface between the laser absorption layer P and the second wafer W2 is reduced by irradiation with laser light L, so the second wafer W2 can be separated without applying a large load.

[0081] The separated second wafer W2 is transferred from the suction pad 210 to the transport arm 23a of the wafer transport device 22, as shown in Figure 17, and then transported to the inversion device 35. After being positioned with its surface W2a facing upwards in the inversion device 35, it is then transported to the second cleaning device 34. In the second cleaning apparatus 34, the surface W2a, which is the side separated from the first wafer W1, is cleaned. The second cleaning apparatus 34 may also clean the back surface W2b along with the surface W2a. Alternatively, separate cleaning units may be provided for cleaning the surface W2a and the back surface W2b, respectively. Subsequently, the second wafer W2, which has been cleaned by the second cleaning device 34, is transported by the wafer transport device 22 to the cassette Cw2 on the cassette mounting table 11.

[0082] Meanwhile, the first wafer W1 held by the suction chuck 200 is transferred to the transport arm 23c as shown in Figure 17 and transported to the first cleaning device 33. This transport by the transport arm 23c may be performed simultaneously with the transport of the second wafer W2 by the transport arm 23a, or it may be performed independently. In the first cleaning device 33, the surface W1a side, which is the side separated from the second wafer W2, specifically the surface of the laser absorption layer P, is cleaned. In addition, the back surface W1b of the first wafer W1 may be cleaned along with the surface of the laser absorption layer P in the first cleaning device 33. Alternatively, separate cleaning units may be provided for cleaning the surface of the laser absorption layer P and the back surface W1b of the first wafer W1, respectively. Subsequently, the first wafer W1, which has been cleaned by the first cleaning device 33, is transported by the wafer transport device 22 to the cassette Cw1 on the cassette mounting table 11.

[0083] Thus, the series of wafer processing operations in wafer processing system 1 is completed.

[0084] In the laser irradiation apparatus 31 according to the above embodiment, the separation of the second wafer W2 was detected based on the difference in the eccentricity of the second wafer W2 relative to the first wafer W1 before and after irradiation of the polymerized wafer T (laser absorption layer P) with laser light L, as described above. However, the configuration of the detection mechanism for the second wafer W2 and the detection method using it are not limited, and the above configuration and method may be replaced with, or in addition to, at least one of the following configurations and methods.

[0085] (1) As described above, if, after irradiation of the polymerized wafer T (laser absorption layer P) with laser light L, the second wafer W2 has actually separated from the first wafer W1 but no eccentricity (horizontal displacement) has occurred, the separation of the second wafer W2 cannot be properly detected. Therefore, after irradiation of the polymerized wafer T with laser light L in the laser irradiation device 31, a load may be applied to the polymerized wafer T when the chuck 100 moves from the processing position A2 to the delivery position A1, thereby shifting the second wafer W2 away from the first wafer W1 (moving the second wafer W2 horizontally). More specifically, for example, the acceleration required for the movement of the chuck 100 from the processing position A2 to the delivery position A1 after irradiation with laser light L may be made larger than the acceleration required for the movement of the chuck 100 from the delivery position A1 to the processing position A2 before irradiation with laser light L, thereby applying an inertial force as a load to the polymerized wafer T. At this time, the magnitude of the load applied to the polymerized wafer T after irradiation with laser light L is controlled to be such that the separated second wafer W2 can be shifted on the first wafer W1, and if the second wafer W2 is not separated, the second wafer W2 will not be shifted on the first wafer W1 (the second wafer W2 will not be separated).

[0086] According to method (1) above, by deliberately applying a load to the polymerized wafer T after irradiation with laser light L, an intentional eccentricity (horizontal displacement) is created between the first wafer W1 and the second wafer W2. This makes it possible to avoid the situation described above where the second wafer W2 is separated from the first wafer W1 but no eccentricity occurs, and as a result, the concern that the second wafer W2 may fall from the first wafer W1 within the system can be suppressed more effectively.

[0087] Furthermore, according to the above method (1), by intentionally creating eccentricity in the first wafer W1 and the second wafer W2 in this way, the cycle time required for processing in the laser irradiation device 31 can be reduced. Specifically, according to method (1) above, by intentionally creating eccentricity in the first wafer W1 and the second wafer W2, eccentricity can be detected by performing area imaging on at least a portion of the outer edge, for example, at only one location in the circumferential direction, instead of imaging the outer edge in the 360-degree circumferential direction of the polymerized wafer T. Therefore, the time required to image the outer edge after irradiation of the polymerized wafer T (laser absorption layer P) with laser light L can be omitted, thereby reducing the cycle time.

[0088] (2) In the laser irradiation device 31, instead of or in addition to the wafer fall prevention pins 101 shown in Figures 4 and 5, a plurality of, for example, three, contact-type sensors 108 as detection units and a calculation unit 109 as a determination unit for determining the separation of the second wafer W2 by the contact-type sensors 108 may be arranged around the periphery of the overlapping wafer T on the holding surface of the chuck 100, as shown in Figure 18. In this case, instead of or in addition to the imaging mechanism 120 according to the above embodiment, these contact-type sensors 108 and the calculation unit 109 constitute the detection mechanism according to the technology of this disclosure. The calculation unit 109 may be independently located in the laser irradiation device 31, or it may be included in the control device 40.

[0089] According to the above configuration (2), instead of imaging the outer edge of the polymerized wafer T (laser absorption layer P) after irradiation with laser light L, the separation of the second wafer W2 can be detected simply by determining whether or not there is contact between the contact sensor 108 and the second wafer W2. Therefore, imaging of the outer edge by the imaging mechanism 120 after irradiation with laser light L of the polymerized wafer T (laser absorption layer P) can be omitted, thereby reducing the cycle time required for processing in the laser irradiation device 31.

[0090] In addition, in the wafer processing system 1 according to the technology disclosed herein, both the imaging mechanism 120 as a detection mechanism and the contact-type sensor 108 may be placed in the laser irradiation device 31. In this case, both detection of the separation of the first wafer W1 and the second wafer W2 by the imaging mechanism 120 and determination of whether or not there is contact with the second wafer W2 by the contact-type sensor 108 may be performed. In this case, if contact between the contact sensor 108 and the second wafer W2 is detected, the detection of separation between the first wafer W1 and the second wafer W2 by the imaging mechanism 120 (imaging of the outer edge of the superimposed wafer T) may be omitted.

[0091] (3) In the above embodiment, the separation of the second wafer W2 was detected based on the difference in the eccentricity of the first wafer W1 and the second wafer W2 before and after irradiation with laser light L, obtained by imaging the outer edges of the polymerized wafer T (first wafer W1 and second wafer W2) with the imaging mechanism 120. However, imaging of the outer edges of the polymerized wafer T (first wafer W1 and second wafer W2) by the imaging mechanism 120 does not necessarily have to be performed before or after irradiation with laser light L, and may be performed only after irradiation with laser light L.

[0092] Even by the method (3) described above, if the outer edges of the polymerized wafer T (first wafer W1 and second wafer W2) are imaged after irradiation with laser light L and the eccentricity (horizontal positional displacement) between the first wafer W1 and the second wafer W2 can be obtained, the separation of the second wafer W2 can be determined based on the eccentricity.

[0093] (4) In the above embodiment, the separation of the second wafer W2 was detected based on the difference in the eccentricity of the first wafer W1 and the second wafer W2 before and after irradiation with laser light L, obtained by imaging the outer edges of the polymerized wafer T (first wafer W1 and second wafer W2) with the imaging mechanism 120. However, depending on the imaging mechanism 120, it may not be possible to image the outer edge of the first wafer W1, which serves as the lower substrate on the chuck 100, due to factors such as the field of view and imaging magnification of the imaging mechanism 120.

[0094] Therefore, in the wafer processing system 1 according to the technology of this disclosure, the imaging mechanism 120 may be configured to image only the outer edge of the second wafer W2, which serves as the upper substrate. In this case, the imaging mechanism 120 acquires positional information of the second wafer W2 on the chuck 100 before and after irradiation with laser light L, and detects the amount of horizontal eccentricity (shift) of the center (more specifically, the rotation center) of the second wafer W2 relative to the center of the chuck 100 before and after irradiation with laser light L. Then, by calculating the difference between the amount of eccentricity of the center of the second wafer W2 relative to the center of the chuck 100 before irradiation with laser light and the amount of eccentricity of the center of the second wafer W2 relative to the center of the chuck 100 after irradiation with laser light, the separation of the second wafer W2 can be determined based on this difference.

[0095] According to the above method (4), even if the imaging mechanism 120 cannot properly image the outer edges of the superimposed wafer T (first wafer W1 and second wafer W2), the separation of the second wafer W2 can be detected by acquiring at least the position information of the second wafer W2.

[0096] (5) In the above embodiment, the imaging mechanism 120 imaged the outer edges of the polymerized wafer T (first wafer W1 and second wafer W2) in a 360-degree circumferential direction to calculate the eccentricity of the first wafer W1 and the second wafer W2, and detected the separation of the second wafer W2. However, imaging of the outer edges of the polymerized wafer T (first wafer W1 and second wafer W2) by the imaging mechanism 120 does not necessarily have to be performed in a 360-degree circumferential direction. Separation of the second wafer W2 can also be detected by imaging at least two locations in the circumferential direction of the polymerized wafer T (for example, a point at 0 degrees circumferentially from the reference position and a point at 90 degrees circumferentially from the reference position).

[0097] According to method (5) described above, instead of imaging the outer edge of the polymerized wafer T in a 360-degree circumferential direction, the separation of the second wafer W2 can be detected by area imaging of the outer edge of the polymerized wafer T at two locations in the circumferential direction. Therefore, the imaging time of the outer edge by the imaging mechanism 120 after irradiation with laser light L can be shortened, thereby reducing the cycle time required for processing in the laser irradiation device 31.

[0098] (6) In the above embodiment, the laser irradiation unit 110 irradiates the central region R1 and the outer peripheral region R2 with laser light L, thereby reducing the bonding strength across the entire surface of the second wafer W2 and the laser absorption layer P. However, if the bonding strength between the second wafer W2 and the laser absorption layer P is reduced across the entire surface in this manner, there is a risk that the second wafer W2 may fall due to the inertial force during the transport of the polymerized wafer T, as described above.

[0099] Therefore, in the wafer processing system 1 according to the technology of this disclosure, the irradiation of laser light L may be stopped in at least a portion of the interface between the second wafer W2 and the laser absorption layer P, and the bonding strength between the second wafer W2 and the laser absorption layer P may be maintained in the at least portion of the area where the laser light L is not irradiated. More specifically, in the wafer processing system 1, as shown in Figure 19, at the interface between the second wafer W2 and the laser absorption layer P, a region that does not reduce the bonding strength between the second wafer W2 and the laser absorption layer P may be formed in a part of the outermost region R0 (see Figure 19(a)) set at the outermost position of the outermost region R2, or in the central region R3 (see Figure 19(b)) set near the center of the central region R1.

[0100] According to the above method (6), by forming a region at least a part of the interface between the second wafer W2 and the laser absorption layer P in which the bonding strength is not reduced (laser light L is not irradiated), the second wafer W2 is not separated from the first wafer W1 in that region, and therefore the falling of the second wafer W2 due to inertial forces acting on the polymerized wafer T can be suppressed.

[0101] In the wafer processing system 1 according to the technology of this disclosure, by detecting the separation of the second wafer W2 prior to the removal of the polymerized wafer T from the laser irradiation device 31 using at least one of the above embodiments and methods (1) to (6), concerns about the second wafer W2 falling from the first wafer W1 within the system can be suppressed.

[0102] Furthermore, even when performing at least one of the above methods (1) to (6), the "acquisition unit" of the detection mechanism can use a length measuring sensor (displacement meter) instead of the camera 121, as described above.

[0103] In the above embodiment, as shown in Figure 9, when the separation of the second wafer W2 was detected in step St6, the first wafer W1 and the second wafer W2 were sequentially removed from the laser irradiation device 31 (steps St8 and St9). However, the operation when separation is detected is not limited to this.

[0104] For example, instead of removing the first wafer W1 and the second wafer W2 independently from the laser irradiation device 31 as described above, the first wafer W1 and the second wafer W2 may be removed together from the laser irradiation device 31 using a transport arm 23b equipped with guide pins 25, similar to step St10. In this case, in order to prevent the second wafer W2 from falling from the first wafer W1, it is desirable to control the lifting speed of the superimposed wafer T by the lifting pins 100a and the transport speed of the superimposed wafer T by the wafer transport device 22 to a lower speed than the specified speed, which is the normal movement speed (when separation of the second wafer W2 is not detected in step St6). For example, if separation of the first wafer W1 and the second wafer W2 is detected in step St6, and it is determined that it is difficult to transport the polymerized wafer T by the wafer transport device 22, the control device 40 may issue an alarm and stop subsequent processing. In this case, the polymerized wafer T may be removed from the laser irradiation device 31 by the operator's manual retrieval.

[0105] In the embodiments described above, the wafer processing method of this disclosure was applied when performing laser lift-off to separate the second wafer W2 from the laser absorption layer P. However, the technology of this disclosure can be arbitrarily applied when separating at least a portion of the first wafer W1 and / or the second wafer W2 from the polymerized wafer T in which the first wafer W1 and the second wafer W2 are bonded.

[0106] For example, in the semiconductor device manufacturing process, a modified layer is formed inside a silicon substrate wafer on which multiple electronic circuits or other devices are formed on the surface by irradiating it with laser light along the plane direction. The wafer is then thinned by separating it using this modified layer as a separation plane. A YAG laser is used for this laser light. The technology disclosed in this disclosure can also be applied when forming a modified layer that serves as a separation plane for wafer thinning. Furthermore, the technology relating to this disclosure can also be applied to a debonding technology for separating the first wafer W1 and the second wafer W2 in a polymerized wafer T formed by bonding the first wafer W1 and the second wafer W2.

[0107] Furthermore, when forming a modified layer by irradiating the inside of a silicon substrate with laser light as described above, and separating the wafer using the modified layer as a starting point, the laser irradiation device 31 only needs to be able to detect the positional displacement between the lower wafer held and left in the chuck 100 and the upper wafer to be removed by separation, instead of the amount of horizontal positional displacement between the first wafer W1 and the second wafer W2 as shown in the above embodiment.

[0108] Specifically, for example, instead of the imaging mechanism 120 or the length measuring sensor, a spectroscopic interferometer may be placed in the laser irradiation device 31, and the space created at the interface between the first wafer W1 and the second wafer W2 (more specifically, the interface between the second wafer W2 and the laser absorption layer P) may be detected in the thickness direction of the polymerized wafer T (position information in the height direction of the polymerized wafer T) to determine whether or not the second wafer W2 is separated from the first wafer W1.

[0109] As shown in Figure 20, a laser irradiation device 310 according to another embodiment is equipped with a spectroscopic interferometer 320. The spectroscopic interferometer 320 has a head 321 and an analysis unit 322.

[0110] The head 321 includes an irradiation unit (not shown) that irradiates the polymerized wafer T on the chuck 100 with measurement light, and a spectroscopic unit (not shown) that receives the measurement light (reflected light) reflected at different height positions of the polymerized wafer T (first height position H1 and second height position H2: see Figures 21 and 22) and detects the interference between the reflected light. The measurement light irradiated from the irradiation unit is arbitrarily selected to be light that is transparent to the second wafer W (silicon).

[0111] The analysis unit 322 calculates the distance between the first height position H1 and the second height position H2 by detecting the interference between the reflected light from the first height position H1 and the second height position H2, respectively, which are detected by the head 321. The analysis unit 322 may be incorporated into the control device 40.

[0112] Next, we will explain the method for determining whether or not the second wafer W2 is separated from the first wafer W1, which is performed using the spectroscopic interferometer 320.

[0113] In the same manner as in the above embodiment, the central region R1 and the outer peripheral region R2 are irradiated with laser light L, and the polymerized wafer T, whose bonding strength has been reduced across the entire surface of the second wafer W2 and the laser absorption layer P, is moved below the spectroscopic interferometer 320 by the drive mechanism 105. Subsequently, while rotating the chuck 100, as shown in Figure 21, the measurement light L2 from the irradiation part of the head 321 is irradiated toward the polymerized wafer T, and the reflected light from the polymerized wafer T is introduced into the spectroscopic unit. When the spectroscopic unit detects interference of reflected light (reflection spectrum) across the entire surface of the polymerized wafer T, it determines that the second wafer W2 has been separated from the first wafer W1.

[0114] However, at this time, as shown in the above embodiment, when the chuck 100 holding the polymerized wafer T, in which the bonding strength of the second wafer W2 and the laser absorption layer P has been reduced across the entire surface, is moved and rotated, There is a risk that the second wafer W2 may fall from the first wafer W1. In view of the above, when moving and rotating the chuck 100 holding the polymerized wafer T, in which the bonding strength has been reduced across the entire surface of the second wafer W2 and the laser absorption layer P, it is desirable to reduce the moving speed and rotation speed. Alternatively, instead of moving and rotating the chuck 100, the spectroscopic interferometer 320 may be moved and rotated relative to the chuck 100 (polymerized wafer T). Furthermore, for example, by arranging the spectroscopic interferometer 320 alongside or integrating it with the laser irradiation device 310, the bonding strength reduction process by the laser irradiation device 310 and the separation determination by the spectroscopic interferometer 320 may be performed simultaneously or continuously.

[0115] A more specific method for determining the separation of the second wafer W2 and the first wafer W1 using the spectroscopic interferometer 320 will be described. When the bonding strength at the interface between the second wafer W2 and the laser absorption layer P decreases due to irradiation with laser light L, and the second wafer W2 separates from the first wafer W1, as shown in Figures 21 and 22, a space S, which is a gap between the second wafer W2 and the first wafer W1, is formed at the separation surface between the second wafer W2 and the first wafer W1 (in the illustrated example, the interface between the second wafer W2 and the laser absorption layer P).

[0116] When a space S is created at the interface between the second wafer W2 and the laser absorption layer P, the measurement light L2 is reflected at the upper and lower surfaces of this space, at two different height positions H1 and H2, respectively. As shown in Figure 21, the reflected light L2a and L2b from these surfaces enter the spectroscopic unit. When the spectroscopic unit detects the interference (reflection spectrum) of the reflected light L2a and L2b, the analysis unit 322 calculates the thickness t of space S (the distance between the first height position H1 and the second height position H2) based on this. The calculated thickness t of space S is output to the control device 40.

[0117] The control device 40 can determine, based on the output thickness t, whether or not a space S has been formed at the interface between the second wafer W2 and the laser absorption layer P. If it is determined that a space S has been formed across the entire surface of the polymerized wafer T (laser absorption layer P), it can be determined that the second wafer W2 and the laser absorption layer P have been completely separated, thereby separating the second wafer W2 from the first wafer W1.

[0118] In one example, whether or not a space S exists at the interface (separation surface) between the second wafer W2 and the laser absorption layer P can be determined by comparing the measurement result (thickness t) obtained by the spectroscopic interferometer 320 after irradiation of the polymerized wafer T with laser light L with a preset first threshold. When the measurement result exceeds the preset first threshold, it is determined that a space S has been formed. The first threshold used for comparison may be, for example, one obtained by measuring the same polymerized wafer T before irradiation with laser light L by the laser irradiation device 31. That is, the first threshold may be obtained by comparing the measurement result in a state where laser light L has not been irradiated (no space S has been created) with the state where laser light L has been irradiated (space S has been created). Alternatively, the first threshold may be obtained in advance from a different wafer (e.g., a dummy wafer). That is, the first threshold may be obtained by comparing the measurement result on a different wafer whose bonding strength has been reduced by irradiation with laser light L with the measurement result on an actual wafer whose bonding strength has been reduced by irradiation with laser light L.

[0119] The thickness t of the calculated space S can be used as the first threshold value. In this case, the first threshold value is the value at which it can be determined that space S has been formed, and is greater than t > 0, which is the thickness at which space S is judged to have been formed. The first threshold value used for comparison may be set to a value greater than 0.

[0120] The control device 40 then determines that the second wafer W2 has not separated from the first wafer W1 and that the second wafer W2 will not fall if the interface region exceeding the first threshold satisfies a predetermined second threshold. The second threshold is set within a range where there is no possibility of the second wafer W2 falling from the first wafer W1 during subsequent transport of the polymerized wafer T. The second threshold is set, for example, by prior experiments or simulations. As a value used for the second threshold, the area ratio of the region where space S is formed to the total area of ​​the polymerized wafer T (laser absorption layer P) in a plan view can be used.

[0121] Furthermore, the detection of reflected light from the polymerized wafer T using the spectroscopic interferometer 320 is preferably performed across the entire polymerized wafer T (laser absorption layer P) in order to appropriately detect the separation of the second wafer W2 from the first wafer W1. However, in order to shorten the inspection time and improve throughput, the detection may be performed only on a portion of the irradiation pitch of the laser beam L irradiated onto the laser absorption layer P (for example, only a portion in the radial or circumferential direction). Alternatively, for example, as shown in Figure 19, if a region is formed at a part of the interface between the second wafer W2 and the laser absorption layer P that does not reduce the bonding strength, only this region that does not reduce the bonding strength may be inspected, and if separation does not occur (thickness t=0), it may be determined that the first wafer W1 and the second wafer W2 have not separated.

[0122] In the above-described other embodiments, the example was given in which the spectroscopic interferometer 320 for detecting the separation of the first wafer W1 and the second wafer W2 is placed inside the laser irradiation device 310. However, the spectroscopic interferometer 320 may be placed outside the laser irradiation device 310. That is, in the technology according to this disclosure, the wafer processing system 1 may independently include the laser irradiation device 31 and an inspection device (not shown) equipped with a spectroscopic interferometer 320 for detecting the separation of the first wafer W1 and the second wafer W2.

[0123] In the above example, the separation of the first wafer W1 and the second wafer W2 was determined by detecting the space S formed at the interface between the first wafer W1 and the second wafer W2 (by detecting that the thickness t>0), but the method for inspecting the separation state is not limited to this.

[0124] Specifically, in the polymerized wafer T in the laser irradiation device 310, where a space S is formed at the interface between the first wafer W1 and the second wafer W2, the height of the polymerized wafer T (more specifically, the height position of the back surface W2b of the second wafer W2) is thought to change due to the delamination of the second wafer W2 and the laser absorption layer P, as shown in Figure 22. In Figure 22, the position of the second wafer W2 before the formation of space S is shown by a dotted line, and the position of the second wafer W2 after the formation of space S is shown by a solid line.

[0125] Therefore, when determining whether or not a space S is formed in order to understand the separation state of the first wafer W1 and the second wafer W2, the height of the polymerized wafer T may be measured. Specifically, for example, an optical flat (reference horizontal plane) may be provided in the spectroscopic interferometer 320, and the interference (reflection spectrum) between the reflected light from this optical flat and the reflected light from the back surface W2b of the second wafer W2 may be detected. In this case, the difference in height between the reference horizontal plane and the polymerized wafer T before and after the formation of space S is calculated, and if this difference changes before and after the formation of space S, it can be determined that space S has been formed. Alternatively, as shown in Figure 19, if a region is formed at a part of the interface between the second wafer W2 and the laser absorption layer P that does not reduce the bonding strength, then if this region is at the same height as the optical flat, it is determined that no space S is formed.

[0126] Furthermore, when measuring the height of the polymerized wafer T (the height position of the back surface W2b of the second wafer W2) in this manner, instead of the thickness t of the space S, which was used as a measurement result for comparison with the first threshold in the above embodiment, the change in the height of the polymerized wafer T due to the formation of space S (see Figure 22) can be used as a measurement result for comparison with the first threshold.

[0127] Furthermore, for example, a displacement sensor (not shown) may be provided above the chuck 100 in place of or in addition to the spectrophotometer 320, and the distance from the displacement sensor to the back surface W2b of the second wafer W2 may be measured. In other words, the separation of the first wafer W1 and the second wafer W2 may be determined by detecting, for example, the amount of change in the distance to the back surface W2b of the second wafer W2 before and after the formation of space S, or the difference between the distance to the back surface W2b in the region where space S is formed and the distance to the back surface W2b in the region where the bonding strength has not been reduced (see Figure 19). In this case, the device can be configured simply by changing the spectrophotometer 320 in the configuration of the laser irradiation device 310 shown in Figure 20 to a displacement sensor (length measuring sensor) not shown.

[0128] In the laser irradiation device described above, the laser beam L was sequentially irradiated onto the central region R1 and the outer region R2 (see Figure 10) of the chuck 100, which were set in advance. However, the decision of whether or not to irradiate the central region R1 with the laser beam L may be made, for example, prior to irradiating the central region R1 with the laser beam L.

[0129] Specifically, when irradiating a polymerized wafer T (laser absorption layer P) with laser light L, first, prior to irradiating the outer peripheral region R2 with laser light L, the positional information of the outer peripheral region R2 is acquired. The acquired positional information may, for example, be the displacement amount obtained by a displacement sensor such as a length measuring sensor (distance between the acquisition point and the polymerized wafer T). After acquiring the positional information of the outer region R2, the irradiation of the outer region R2 with laser light L is then started. The method of irradiating the outer region R2 with laser light L is the same as the method of irradiating the laser light L described above. Next, prior to irradiating the central region R1 with laser light L, the position information of the outer region R2 is reacquired. This reacquisition of position information may be performed by temporarily interrupting the laser processing (rotation of the polymerized wafer T and irradiation with laser light L) prior to irradiating the central region R1 with laser light L, or it may be performed continuously throughout the laser processing of the outer region R2.

[0130] Here, if there is no change in the positional information of the outer peripheral region R2 before and after irradiation with laser light L, or if the change does not exceed a predetermined threshold, it is considered that complete delamination has not occurred at the interface between the second wafer W2 and the laser absorption layer P in the outer peripheral region R2, and the bonding strength is still maintained. On the other hand, if there is a change in the positional information of the outer peripheral region R2 that exceeds a threshold before and after irradiation with laser light L, it is considered that delamination occurred at the interface between the second wafer W2 and the laser absorption layer P due to some factor during irradiation of the outer peripheral region R2 with laser light L, and the bonding strength decreased.

[0131] Therefore, if there is no change in the positional information of the outer region R2 before and after irradiation with laser light L, and the bonding strength is considered to be maintained, the irradiation of the central region R1 with laser light L is continued. The polymerized wafer T, in which the bonding strength between the second wafer W2 and the laser absorption layer P has decreased, is then transported to the separation device 32, where the first wafer W1 and the second wafer W2 are separated.

[0132] On the other hand, if the positional information of the outer region R2 changes by more than a threshold before and after irradiation with laser light L, and it is considered that the bonding strength has decreased, the central region R1 is not irradiated with laser light L. Therefore, the bonding strength between the second wafer W2 and the laser absorption layer P is maintained in the central region R1. In this case, the polymerized wafer T is recovered from the laser irradiation device without being transported to the separation device 32. At this time, the polymerized wafer T may be recovered into a cassette via a transport device, or it may be removed from the laser irradiation device by manual recovery by an operator.

[0133] In this way, by determining whether or not to irradiate the central region R1 with laser light L according to the delamination state of the outer peripheral region R2, for example, complete delamination across the entire interface between the second wafer W2, including the central region R1, and the laser absorption layer P, the polymerized wafer T can be safely transported out without the second wafer W2 falling within the laser irradiation device.

[0134] In this explanation, positional information of the outer region R2 was acquired prior to irradiation with laser light L, and the delamination state was determined by comparing the positional information before and after irradiation with laser light L. However, if the delamination state in the outer region R2 can be determined without comparing the positional information before and after irradiation with laser light L, it is not necessarily required to acquire positional information before irradiation with laser light L; at the very least, positional information should be acquired before irradiation with laser light L to confirm the delamination state in the central region R1.

[0135] In the embodiments described above, the laser absorption layer P, the device layer D2, and the surface film F2 are stacked in this order on the surface W2a of the second wafer W2, and the interface between the laser absorption layer P and the second wafer W2 is set as the separation plane between the first wafer W1 and the second wafer W2. However, the position of the separation plane is not limited to this. Specifically, for example, on the surface W2a side of the second wafer W2, a delamination-promoting film (not shown) may be formed between the second wafer W2 and the laser absorption layer P to promote delamination between the first wafer W1 and the second wafer W2, and the interface between the delamination-promoting film and the second wafer W2 may be set as the separation surface. In this case, it is desirable that the material constituting the delamination-promoting film is selected such that the adhesion force between the delamination-promoting film and the second wafer W2 (silicon, etc.) is at least smaller than the adhesion force between the delamination-promoting film and the laser absorption layer P (oxide film).

[0136] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0137] 1. Wafer Processing System 31 Laser irradiation device 40 Control device 100 Chuck 104 Rotation mechanism 105 Drive mechanism 108 Contact Sensor 110 Laser irradiation area 120 Imaging mechanism L Laser light T Polymerized wafer W1 First wafer W2, second wafer

Claims

1. A substrate processing system for processing substrates, A substrate holding portion having a holding surface for holding the substrate, A laser irradiation unit that irradiates the substrate held on the holding surface with laser light to form a separation surface that serves as a base point for separating the substrate, A separation unit that separates the substrate with the separation surface as the base point, The system includes a substrate transport mechanism for transporting the aforementioned substrate, The substrate transport mechanism includes a plurality of transport arms, At least one of the multiple transport arms has a plurality of guide pins arranged around the substrate, The substrate transport mechanism is A substrate processing system that transports the substrate, after irradiation with laser light, from the laser irradiation unit to the separation unit, and holds and transports it using the transport arm having the guide pins.

2. The substrate processing system according to claim 1, wherein at least one of the plurality of transport arms has a second holding surface for holding the substrate on the lower side of the transport arm.

3. The substrate transport mechanism is The substrate processing system according to claim 2, wherein the separated substrate is carried out from the separation unit by being held on the second holding surface of the transport arm having the second holding surface on its lower side.

4. The substrate processing system according to claim 1, wherein each of the plurality of transport arms has a suction portion for adsorbing and holding the substrate.

5. The substrate holding portion is A plurality of lifting pins that support and raise / lower the substrate held on the holding surface from below, The substrate processing system according to claim 1, further comprising: a plurality of substrate fall prevention pins arranged around the periphery of the substrate held on the holding surface and configured to be vertically movable in conjunction with the vertical pins.

6. The substrate holding portion is equipped with a drive mechanism for moving it in the horizontal direction. The aforementioned drive mechanism is A transfer position for transferring the substrate to the substrate holding portion, The substrate holding portion is configured to be movable between a processing position where the separation surface is formed by irradiation with the laser light, The control mechanism that controls the operation of the drive mechanism is, The acceleration during the movement of the substrate holding part from the processing position to the handover position after irradiation with the laser light is, The substrate processing system according to claim 1, further comprising the execution of a control that increases the acceleration of the substrate holding portion when it moves from the receiving position to the processing position before irradiation with the laser light.

7. Equipped with a control mechanism, The control mechanism is The substrate is transported to the separation section using the substrate transport mechanism. A substrate processing system according to any one of claims 1 to 6, wherein control is performed to set the transport speed of the substrate to a lower speed than a specified speed when transporting it to the separation unit.

8. A substrate processing method for processing a substrate, To provide the aforementioned substrate to the holding surface of the substrate holding portion, In the laser irradiation section, laser light is irradiated onto the substrate held on the holding surface to form a separation surface that serves as the base point for separating the substrate, In the separation section, the substrate is separated using the separation surface as a reference point, This includes transporting the substrate by at least one of a plurality of transport arms, At least one of the multiple transport arms has a plurality of guide pins arranged around the substrate, Transporting the aforementioned substrate is A substrate processing method, comprising transporting the substrate after irradiation with laser light from the laser irradiation unit to the separation unit, and holding and transporting the substrate with the transport arm having the guide pins.

9. The substrate processing method according to claim 8, wherein at least one of the plurality of transport arms has a second holding surface for holding the substrate on the lower side of the transport arm.

10. Transporting the aforementioned substrate is The substrate processing method according to claim 9, further comprising transporting the separated substrate from the separation unit by holding it on the second holding surface of the transport arm having the second holding surface on its lower side.

11. Each of the multiple transport arms has a suction part for adsorbing and holding the substrate, Transporting the aforementioned substrate is The substrate processing method according to claim 8, further comprising transporting the substrate after irradiation with the laser light by adsorption and holding it in the adsorption portion of the transport arm having the guide pins.

12. The substrate holding portion is A plurality of lifting pins that support and raise / lower the substrate held on the holding surface from below, The system includes a plurality of pins for preventing substrates from falling, which are arranged around the periphery of the substrate held by the holding surface and are configured to move up and down integrally with the lifting pins. The substrate processing method according to claim 8, wherein when the substrate held on the holding surface is supported from below by a plurality of lifting pins and raised and lowered, the substrate fall prevention pin is raised and lowered together with the lifting pins.

13. The substrate holding portion is equipped with a drive mechanism for moving it in the horizontal direction. The aforementioned drive mechanism is A transfer position for transferring the substrate to the substrate holding portion, The substrate holding portion is configured to be movable between a processing position where the separation surface is formed by irradiation with the laser light, The acceleration during the movement of the substrate holding part from the processing position to the handover position after irradiation with the laser light is, The substrate processing method according to claim 12, further comprising making the acceleration greater than the acceleration when the substrate holding portion moves from the handover position to the processing position before irradiation with the laser light.

14. When transporting the substrate to the separation section, A substrate processing method according to any one of claims 8 to 13, comprising setting the transport speed of the substrate to a lower speed than the specified speed when transporting it to the separation section.

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