SUBSTRATE PROCESSING APPARATUS, SUBSTRATE PROCESSING METHOD, AND SUBSTRATE MANUFACTURING METHOD

Abstract

A substrate processing device for processing a polymerized substrate in which a first substrate and a second substrate are bonded, the substrate processing device comprising a substrate holding unit for holding the polymerized substrate, a laser irradiation unit for irradiating a laser absorption layer formed between the first substrate and the second substrate with pulsed laser light, a movement mechanism for causing the substrate holding unit and the laser irradiation unit to move relative to each other, and a control unit for controlling the laser irradiation unit and the movement mechanism, the control unit setting an interval for the laser light radiated to the laser absorption layer on the basis of the thickness of the laser absorption layer.

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing apparatus, a substrate processing method, and a substrate manufacturing method. [Background technology]

[0002] Patent Document 1 discloses a method for manufacturing a semiconductor device, which includes a heating step of locally heating a peeling oxide film by irradiating a CO2 laser from the back surface of a semiconductor substrate, and a transfer step of transferring a semiconductor element to a destination substrate by causing peeling in the peeling oxide film and / or at the interface between the peeling oxide film and the semiconductor substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-220749 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure improves the throughput of substrate processing using laser light for a laminated substrate in which a first substrate and a second substrate are bonded together. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate processing apparatus for processing a laminated substrate formed by bonding a first substrate and a second substrate, the apparatus including: a substrate holding unit for holding the laminated substrate; a laser irradiation unit for irradiating a laser absorption layer formed between the first substrate and the second substrate with pulsed laser light; a movement mechanism for relatively moving the substrate holding unit and the laser irradiation unit; and a control unit for controlling the laser irradiation unit and the movement mechanism, the control unit adjusting a pulse width of the laser light irradiated to the laser absorption layer based on a thickness of the laser absorption layer. pitch Set. Effect of the Invention

[0006] According to the present disclosure, it is possible to improve the throughput of substrate processing using laser light for a laminated substrate in which a first substrate and a second substrate are bonded together. [Brief description of the drawings]

[0007] [Figure 1] 1 is a side view showing an outline of a configuration of overlapping wafers processed in a wafer processing system. [Diagram 2] 1 is a plan view illustrating a schematic configuration of a wafer processing system. [Diagram 3] 1 is a side view showing an outline of a configuration of a wafer processing apparatus; [Figure 4] FIG. 1 is a plan view showing an outline of a configuration of a wafer processing apparatus. [Diagram 5] FIG. 2 is an explanatory diagram showing a state in which a laser absorbing film is irradiated with laser light. [Figure 6] FIG. 2 is an explanatory diagram showing a state in which a laser absorbing film is irradiated with laser light. [Figure 7] FIG. 11 is an explanatory diagram showing a state in which the first wafer is peeled off from the second wafer. [Figure 8] 1 is an explanatory diagram of an irradiation interval of a laser light irradiated onto a laser absorbing film. FIG. [Figure 9] 1 is a graph showing a tendency of the relationship between the thickness of a laser absorbing film and the pulse energy of a laser beam. [Figure 10] 1 is a graph showing a trend in the relationship between the thickness of a laser absorbing film and the throughput of wafer processing. [Figure 11] 1 is a table showing the correlation between the thickness of a laser absorbing film and the irradiation interval of laser light. [Figure 12] 11 is an explanatory diagram showing main steps of another wafer processing in the wafer processing system. FIG. [Figure 13] 11 is an explanatory diagram showing main steps of another wafer processing in the wafer processing system. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the manufacturing process of semiconductor devices, a first substrate (silicon substrate such as a semiconductor substrate) on which a plurality of devices such as electronic circuits are formed is bonded to a second substrate to form a laminated substrate, and a device layer on the surface of the first substrate is transferred to the second substrate. In this case, a so-called laser lift-off may be performed in which the first substrate is peeled off from the second substrate using, for example, a laser beam. In the laser lift-off, a laser absorption layer (e.g., an oxide film) formed between the first substrate and the second substrate is irradiated with a laser beam to cause peeling at the interface between the first substrate and the second substrate.

[0009] The method described in the above-mentioned Patent Document 1 is a method for manufacturing a semiconductor device using this laser lift-off. Patent Document 1 describes that by increasing the thickness of the oxide film, it is possible to prevent characteristic fluctuations and damages of the semiconductor elements in the device layer, and perform stable laser processing. However, there is no consideration or suggestion of improving the throughput of this laser processing. Therefore, there is room for improvement in conventional laser processing.

[0010] The technology disclosed herein improves the throughput of substrate processing using laser light for a laminated substrate in which a first substrate and a second substrate are bonded together. Hereinafter, a wafer processing apparatus as a substrate processing apparatus, a wafer processing method as a substrate processing method, and a wafer manufacturing method as a substrate manufacturing method according to the present embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0011] In a wafer processing system 1 according to this embodiment, which will be described later, processing is performed on a laminated wafer T, which is a laminated substrate in which a first wafer W as a first substrate and a second wafer S as a second substrate are bonded together, as shown in Fig. 1. Hereinafter, in the first wafer W, the surface that is bonded to the second wafer S is referred to as the front surface Wa, and the surface opposite the front surface Wa is referred to as the back surface Wb. Similarly, in the second wafer S, the surface that is bonded to the first wafer W is referred to as the front surface Sa, and the surface opposite the front surface Sa is referred to as the back surface Sb.

[0012] The first wafer W is a semiconductor wafer such as a silicon substrate. A peeling-promoting film Fm, a laser absorbing film Fw as a laser absorbing layer, a device layer (not shown) including a plurality of devices, and a surface film Fe are laminated on the surface Wa of the first wafer W. The peeling-promoting film Fm is a film that is transparent to the laser light from the laser irradiation system 110 described later and has a smaller adhesion to the first wafer W (silicon) than that to the laser absorbing film Fw, such as a SiN film. The laser absorbing film Fw is a film that can absorb the laser light from the laser irradiation system 110 described later, such as an oxide film (SiO2 film, TEOS film), etc. The surface film Fe is, for example, an oxide film (THOX film, SiO2 film, TEOS film), a SiC film, a SiCN film, or an adhesive.

[0013] The second wafer S is also a semiconductor wafer such as a silicon substrate. A device layer (not shown) including a plurality of devices is formed on the surface Sa of the second wafer S, and a surface film Fs is further laminated thereon. Examples of the surface film Fs include an oxide film (THOX film, SiO2 film, TEOS film), a SiC film, a SiCN film, or an adhesive. The surface film Fe of the first wafer W and the surface film Fs of the second wafer S are then bonded together.

[0014] 2, the wafer processing system 1 has a configuration in which a load / unload block 10, a transport block 20, and a processing block 30 are integrally connected. The load / unload block 10 and the processing block 30 are provided around the transport block 20. Specifically, the load / unload block 10 is disposed on the negative Y-axis side of the transport block 20. A wafer processing device 31, which will be described later, in the processing block 30 is disposed on the negative X-axis side of the transport block 20, and a cleaning device 32, which will be described later, is disposed on the positive X-axis side of the transport block 20.

[0015] The carry-in / out block 10 carries in and out cassettes Ct, Cw, and Cs, each capable of accommodating a plurality of overlapped wafers T, a plurality of first wafers W, and a plurality of second wafers S, for example, between the outside and the inside of the device. The carry-in / out block 10 is provided with a cassette mounting table 11. In the illustrated example, the cassette mounting table 11 can freely mount a plurality of cassettes, for example, three cassettes Ct, Cw, and Cs, in a line in the X-axis direction. The number of cassettes Ct, Cw, and Cs mounted on the cassette mounting table 11 is not limited to the present embodiment and can be determined arbitrarily.

[0016] The transfer block 20 is provided with a wafer transfer device 22 that is movable on a transfer path 21 extending in the X-axis direction. The wafer transfer device 22 has, for example, two transfer arms 23, 23 that hold and transfer the overlapped wafer T, the first wafer W, and the second wafer S. Each transfer arm 23 is configured to be movable in the horizontal direction, the vertical direction, around a horizontal axis, and around a vertical axis. The configuration of the transfer arm 23 is not limited to this embodiment, and may be any configuration. The wafer transfer device 22 is configured to be able to transfer the overlapped wafer T, the first wafer W, and the second wafer S to the cassettes Ct, Cw, and Cs on the cassette mounting table 11, the wafer processing device 31, and the cleaning device 32, which will be described later.

[0017] The processing block 30 includes a wafer processing device 31 and a cleaning device 32. The wafer processing device 31 irradiates a laser absorbing film Fw of the first wafer W with laser light to separate the first wafer W from the second wafer S. The configuration of the wafer processing device 31 will be described later.

[0018] The cleaning device 32 cleans the outermost surface (surface of the peeling-promoting film Fm) on the front surface Sa side of the second wafer S separated in the wafer processing device 31. For example, a brush is brought into contact with the surface of the peeling-promoting film Fm to scrub the surface. Note that a pressurized cleaning liquid may be used to clean the front surface. The cleaning device 32 may also be configured to clean the back surface Sb of the second wafer S as well as the front surface Sa side.

[0019] The above-described wafer processing system 1 is provided with a control device 40 as a control unit. The control device 40 is, for example, a computer, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the laminated wafer T in the wafer processing system 1. The program storage unit also stores a program for controlling the operation of a drive system such as the above-described various processing devices and transport device to realize wafer processing in the wafer processing system 1, which will be described later. The above-described program may be recorded in a computer-readable storage medium H and installed in the control device 40 from the storage medium H.

[0020] Next, the above-mentioned wafer processing apparatus 31 will be described.

[0021] 3 and 4, the wafer processing apparatus 31 has a chuck 100 as a substrate holding part for holding the upper surface of the overlapped wafer T. The chuck 100 holds the back surface Sb of the second wafer S by suction.

[0022] The chuck 100 is supported by a slider table 102 via an air bearing 101. A rotation mechanism 103 is provided on the lower surface side of the slider table 102. The rotation mechanism 103 incorporates, for example, a motor as a drive source. The chuck 100 is configured to be rotatable around a θ-axis (vertical axis) via the air bearing 101 by the rotation mechanism 103. The slider table 102 is configured to be movable along a rail 105 extending in the Y-axis direction by a horizontal movement mechanism 104 provided on the lower surface side of the slider table 102. The rail 105 is provided on a base 106. The drive source of the horizontal movement mechanism 104 is not particularly limited, but for example, a linear motor is used. In this embodiment, the above-mentioned rotation mechanism 103 and horizontal movement mechanism 104 correspond to the "movement mechanism" according to the technology of the present disclosure.

[0023] A laser irradiation system 110 serving as a laser irradiation unit is provided above the chuck 100. The laser irradiation system 110 has a laser head 111 and a lens 112 serving as a laser irradiation unit. The lens 112 may be configured to be freely movable up and down by an elevator mechanism (not shown).

[0024] The laser head 111 has a laser oscillator (not shown) that oscillates a laser beam in a pulsed manner. That is, the laser beam irradiated from the laser irradiation system 110 to the laminated wafer T held on the chuck 100 is a so-called pulsed laser, and its power repeatedly changes between 0 (zero) and a maximum value. In this embodiment, the laser beam is a CO2 laser beam, and the wavelength of the CO2 laser beam is, for example, 8.9 μm to 11 μm. The laser head 111 may have other devices besides the laser oscillator, such as an amplifier.

[0025] The lens 112 is a cylindrical member, and irradiates laser light onto the laminated wafer T held by the chuck 100. The laser light emitted from the laser irradiation system 110 passes through the first wafer W, and is irradiated onto and absorbed by the laser absorbing film Fw.

[0026] As shown in FIG. 4, a transfer pad 120 serving as a peeling processing section is provided above the chuck 100. The transfer pad 120 is configured to be freely raised and lowered by a lifting mechanism (not shown). The transfer pad 120 has an adsorption surface for the first wafer W. The transfer pad 120 transfers the first wafer W between the chuck 100 and the transfer arm 23. Specifically, after the chuck 100 is moved to a position below the transfer pad 120 (a transfer position with the transfer arm 23), the transfer pad 120 adsorbs and holds the back surface Wb of the first wafer W and peels it off from the second wafer S. Then, the peeled first wafer W is transferred from the transfer pad 120 to the transfer arm 23 and carried out of the wafer processing apparatus 31.

[0027] In this embodiment, the laser irradiation unit (laser irradiation system 110) and the peeling processing unit (transport pad 120) are provided inside the same wafer processing apparatus 31, but the laser irradiation unit and the peeling processing unit may be provided as separate processing apparatuses.

[0028] Next, a description will be given of wafer processing performed using the wafer processing system 1 configured as above. In this embodiment, the first wafer W and the second wafer S are bonded in a bonding device (not shown) outside the wafer processing system 1 to form a laminated wafer T in advance.

[0029] First, a cassette Ct storing a plurality of overlapped wafers T is placed on the cassette placement table 11 of the carry-in / out block 10.

[0030] Next, the overlapped wafer T is removed from the cassette Ct by the wafer transfer device 22 and transferred to the wafer processing device 31. In the wafer processing device 31, the overlapped wafer T is transferred from the transfer arm 23 to the chuck 100 and adsorbed and held by the chuck 100. Next, the horizontal movement mechanism 104 moves the chuck 100 to a processing position. This processing position is a position where the overlapped wafer T (laser absorbing film Fw) can be irradiated with laser light from the laser irradiation system 110.

[0031] Next, as shown in Fig. 5 and Fig. 6, the laser irradiation system 110 irradiates the laser absorbing film Fw with pulsed laser light L. The laser light L passes through the first wafer W and the peeling promoting film Fm from the rear surface Wb side of the first wafer W, and is absorbed in the laser absorbing film Fw. At this time, the laser absorbing film Fw accumulates energy by absorbing the laser light L, and the temperature rises and the film expands. The shear stress caused by the expansion of the laser absorbing film Fw is also transmitted to the peeling promoting film Fm. Then, since the adhesion force of the peeling promoting film Fm to the first wafer W is smaller than the adhesion force of the peeling promoting film Fm to the laser absorbing film Fw, peeling occurs at the interface between the first wafer W and the peeling promoting film Fm.

[0032] When the laser absorbing film Fw is irradiated with the laser light L, the chuck 100 (superimposed wafer T) is rotated by the rotation mechanism 103, and the chuck 100 is moved in the Y-axis direction by the horizontal movement mechanism 104. Then, the laser light L is irradiated from the outside to the inside in the radial direction onto the laser absorbing film Fw, and as a result, the laser light L is irradiated from the outside to the inside in a spiral shape. Note that the black arrow in FIG. 6 indicates the rotation direction of the chuck 100.

[0033] The laser light L may be irradiated in a concentric ring shape. In addition, the laser light L may be irradiated from the inside to the outside in the radial direction in the laser absorbing film Fw. In addition, after the laser light L is irradiated in a fan shape with the center of the laser absorbing film Fw as the apex, the chuck 100 may be moved, and the laser light L may be irradiated in a further fan shape to the unirradiated portion of the laser light L, and this may be repeated to irradiate the entire laser absorbing film Fw. Furthermore, the chuck 100 may be moved, and the laser light L may be irradiated in a linear shape to irradiate the entire laser absorbing film Fw.

[0034] In addition, in this embodiment, when irradiating the laser absorbing film Fw with the laser light L, the chuck 100 is rotated, but the lens 112 may be moved to rotate the lens 112 relatively to the chuck 100. In addition, the chuck 100 is moved in the Y-axis direction, but the lens 112 may be moved in the Y-axis direction.

[0035] Thus, in the wafer processing apparatus 31, the laser absorbing film Fw is irradiated with the laser light L in a pulsed manner. When the laser light L is oscillated in a pulsed manner, the peak power (maximum intensity of the laser light) can be increased to cause peeling at the interface between the first wafer W and the peeling promoting film Fm. As a result, the first wafer W can be appropriately peeled off from the second wafer S.

[0036] In this embodiment, the circumferential interval (pulse pitch) and radial interval (index pitch) of the laser light L irradiated to the laser absorbing film Fw are set based on the thickness of the laser absorbing film Fw. The method of setting the pulse pitch and the index pitch will be described later.

[0037] After the laser absorbing film Fw is irradiated with the laser light L as described above, the chuck 100 is moved to the delivery position by the horizontal movement mechanism 104. Then, as shown in FIG. 7(a), the back surface Wb of the first wafer W is adsorbed and held by the transfer pad 120. Then, as shown in FIG. 7(b), while the transfer pad 120 is adsorbed and holding the first wafer W, the transfer pad 120 is raised to peel off the first wafer W from the peeling promotion film Fm. At this time, since peeling has occurred at the interface between the first wafer W and the peeling promotion film Fm due to the irradiation of the laser light L as described above, the first wafer W can be peeled off from the peeling promotion film Fm without applying a large load. Then, the device layer of the first wafer W is transferred to the second wafer S. When the transfer pad 120 is raised, the transfer pad 120 may be rotated around a vertical axis to peel off the first wafer W.

[0038] The peeled first wafer W is transferred from the transfer pad 120 to the transfer arm 23 of the wafer transfer device 22, and transferred to the cassette Cw of the cassette mounting table 11. The first wafer W unloaded from the wafer processing device 31 may be transferred to the cleaning device 32 before being transferred to the cassette Cw, and its peeled surface, that is, the front surface Wa, may be cleaned. In this case, the first wafer W may be reversed from the front to the back surface by the transfer pad 120, and then transferred to the transfer arm 23.

[0039] Meanwhile, the second wafer S held by the chuck 100 is transferred to the transfer arm 23 and transferred to the cleaning device 32. In the cleaning device 32, the outermost surface (the surface of the peeling-promoting film Fm) on the side of the front surface Sa, which is the peeling surface, is scrubbed and cleaned. Note that in the cleaning device 32, the back surface Sb of the second wafer S may also be cleaned in addition to the surface of the peeling-promoting film Fm. Also, separate cleaning units may be provided for cleaning the front surface of the peeling-promoting film Fm and the back surface Sb of the second wafer S, respectively.

[0040] Thereafter, the second wafer S on which all the processes have been performed is transferred by the wafer transfer device 22 to the cassette Cs on the cassette mounting table 11. In this manner, a series of wafer processes in the wafer processing system 1 is completed.

[0041] Next, a method for setting a pulse pitch P, which is an irradiation interval of the laser light L in the circumferential direction shown in FIG. 8, and an index pitch Q, which is an irradiation interval of the laser light L in the radial direction, when the laser light L is irradiated to the laser absorbing film Fw in the wafer processing apparatus 31 will be described.

[0042] First, the inventors investigated the pulse energy (vertical axis of FIG. 9) of the laser light L required to peel the first wafer W from the second wafer S when the thickness (horizontal axis of FIG. 9) of the laser absorbing film Fw (SiO2 film) was changed as shown in FIG. 9. When the thickness of the laser absorbing film Fw is small, the volume that absorbs the pulse energy is small and the absorption efficiency is low, so the pulse energy required for peeling is large. On the other hand, when the laser absorbing film Fw is large, the pulse energy required for peeling is small.

[0043] Next, the inventors investigated the throughput of wafer processing (vertical axis of FIG. 10) when the thickness of the laser absorbing film Fw (SiO2 film) was changed (horizontal axis of FIG. 10) as shown in FIG. 10. As described above, when the thickness of the laser absorbing film Fw is small, the pulse energy required for peeling becomes large. In such a case, if the pulse energy is to be increased, the pulse frequency of the laser light L must be reduced, and the throughput of wafer processing decreases. On the other hand, when the laser absorbing film Fw is large, the pulse energy required for peeling is small and the pulse frequency of the laser light L can be increased, and therefore the throughput of wafer processing improves.

[0044] As described above, there is a correlation between the thickness of the laser absorbing film Fw and the throughput of the wafer processing. As a result of further intensive study, the inventors have found that there is a correlation between the thickness of the laser absorbing film Fw (SiO2 film) and the pulse pitch P and index pitch Q of the laser light L to enable peeling, as shown in FIG. 11. That is, the first wafer W can be peeled off from the second wafer S according to the thickness of the laser absorbing film Fw. For example, the first wafer W can be peeled off from the second wafer S in the range of the pulse pitch P and index pitch Q in the shaded portion in FIG. 11. Note that, although the pulse pitch P and index pitch Q are the same in the example shown in FIG. 11, these pulse pitch P and index pitch Q may be different.

[0045] The method of setting the pulse pitch P and the index pitch Q in this embodiment is based on the above knowledge, and the pulse pitch P and the index pitch Q are set based on the thickness of the laser absorbing film Fw.

[0046] First, the thickness of the laser absorbing film Fw is acquired. The thickness of the laser absorbing film Fw may be acquired by the wafer processing device 31, or may be acquired in advance outside the wafer processing device 31. The method of acquiring the thickness of the laser absorbing film Fw is not particularly limited, and may be measured directly or indirectly by a sensor or the like, or may be acquired by capturing an image of the laminated wafer T by a camera or the like. The thickness of the laser absorbing film Fw thus acquired is output to the control device 40.

[0047] The control device 40 sets the pulse pitch P and the index pitch Q based on the acquired thickness of the laser absorbing film Fw. For example, the pulse pitch P and the index pitch Q may be set so that the processing time for performing wafer processing using laser light (i.e., the laser processing time in this disclosure) is minimized and the throughput is maximized. For example, in the example shown in FIG. 11, the pulse pitch P and the index pitch Q are set to the maximum pitch at which peeling is possible according to the thickness of the laser absorbing film Fw. In such a case, the throughput of the wafer processing can be maximized and productivity can be improved. Note that the pulse pitch P and the index pitch Q may be the same as described above, or may be different.

[0048] Also, for example, the pulse pitch P and the index pitch Q may be set so that the processing time (throughput) of the wafer processing becomes the processing time (throughput) required for the wafer processing device 31. In such a case, the device capacity of the wafer processing device 31 can be maximized while ensuring the throughput of the wafer processing.

[0049] As described above, according to this embodiment, the pulse pitch P and the index pitch Q of the laser light L are set based on the thickness of the laser absorption film Fw, so that the throughput of the wafer processing can be appropriately controlled.

[0050] Next, a method for manufacturing the overlapped wafer T based on the above-mentioned knowledge that there is a correlation between the thickness of the laser absorbing film Fw and the pulse pitch P and index pitch Q of the laser light L will be described.

[0051] In a bonding device (not shown) outside the wafer processing system 1, the first wafer W and the second wafer S are bonded to produce a laminated wafer T. At this time, a peeling promoting film Fm, a laser absorbing film Fw, a device layer (not shown), and a surface film Fe are laminated on the surface Wa of the first wafer W. Also, a device layer (not shown) and a surface film Fs are laminated on the surface Sa of the second wafer S. Then, the surface film Fe of the first wafer W and the surface film Fs of the second wafer S are bonded.

[0052] The thickness of the laser absorbing film Fw is set based on the pulse pitch P and index pitch Q of the laser light L irradiated onto the laser absorbing film Fw in the wafer processing apparatus 31 after manufacturing the overlapped wafer T. That is, based on the pulse pitch P and index pitch Q which are set from the processing time (throughput) of the wafer processing in the wafer processing apparatus 31 as described above, the thickness of the laser absorbing film Fw is set by using, for example, the correlation shown in FIG.

[0053] As described above, according to this embodiment, the thickness of the laser absorption film Fw can be optimally set based on the pulse pitch P and the index pitch Q of the laser light L, so that the throughput of wafer processing in the wafer processing apparatus 31 can be appropriately controlled.

[0054] In the above embodiment, the method of setting the pulse pitch P and the index pitch Q of the present disclosure is applied when irradiating the laser absorbing film Fw of the overlapped wafer T with laser light L to peel off the first wafer W from the second wafer S, i.e., when performing laser lift-off, but the laser processing to which the method is applicable is not limited to this.

[0055] 12, the method of setting the pulse pitch P and the index pitch Q of the present disclosure may also be applied when performing so-called edge trimming, which removes the peripheral portion We of the first wafer W in the overlapped wafer T. Note that the peripheral portion We of the first wafer W is, for example, in the range of 0.5 mm to 3 mm in the radial direction from the outer end of the first wafer W.

[0056] 12(a), a laser beam (e.g., a YAG laser beam) is irradiated to the inside of the first wafer W to form a peripheral modified layer M1 and divided modified layers M2. The peripheral modified layer M1 is formed in an annular shape concentric with the first wafer W. The divided modified layers M2 are formed by extending radially from the peripheral modified layer M1. Then, as shown in FIG. 12(b), a laser beam (e.g., a CO2 laser beam) is irradiated in pulses onto the laser absorption film Fw at a position corresponding to the peripheral portion We, to form an unbonded region Ae in which the bonding strength between the first wafer W and the second wafer S is reduced. 12(c), the peripheral portion We of the first wafer W is removed, that is, edge trimmed. At this time, the peripheral portion We is peeled off from the center of the first wafer W using the peripheral modified layer M1 as a base point, and is also completely peeled off from the second wafer S using the unbonded region Ae as a base point. At this time, the removed peripheral portion We is also divided into small pieces using the divided modified layer M2 as a base point.

[0057] In this embodiment, when the laser absorbing film Fw is irradiated with laser light as shown in Fig. 12(b), the pulse pitch P and index pitch Q of the laser light are set based on the laser absorbing film Fw in the same manner as in the above embodiment. As a result, the same effect as in the above embodiment can be obtained, that is, the throughput of the wafer processing can be improved.

[0058] For example, as shown in FIG. 13, the method of setting the pulse pitch P and index pitch Q disclosed herein may be applied even when an internal surface modification layer M3 serving as a starting point for thinning the first wafer W is formed inside the first wafer W, and the peripheral portion We is removed integrally with the back surface Wb side of the first wafer W.

[0059] 13(a), a laser beam is irradiated to the inside of the first wafer W to sequentially form a peripheral modified layer M1 and an internal surface modified layer M3. The internal surface modified layer M3 is formed inside the first wafer W by extending in the surface direction. Thereafter, as shown in FIG. 13(b), a laser beam (for example, a CO 2 laser beam) is irradiated in a pulsed manner onto the laser absorption film Fw at a position corresponding to the peripheral edge portion We, thereby forming an unbonded region Ae. Thereafter, as shown in FIG. 13(c), the first wafer W is thinned from the inner surface modified layer M3 as a base point, and the peripheral portion We is peeled off and removed integrally from the peripheral modified layer M1 and the unbonded region Ae as base points.

[0060] In this embodiment, when the laser absorbing film Fw is irradiated with laser light as shown in FIG. 13(b), the pulse pitch P and index pitch Q of the laser light are set based on the laser absorbing film Fw as in the above embodiment. As a result, the same effect as in the above embodiment can be obtained, that is, the throughput of the wafer processing can be improved. In this embodiment, a device layer is formed on the front surface Wa of the first wafer W, but the technology of the present disclosure can also be applied to the case where the same processing is performed on, for example, an SOI wafer on which no device layer is formed.

[0061] In the example shown in Fig. 12, the order of forming the peripheral modified layer M1 and the divided modified layer M2 in Fig. 12(a) and the unbonded region Ae in Fig. 12(b) may be reversed. Similarly, in the example shown in Fig. 13, the order of forming the peripheral modified layer M1 and the internal surface modified layer M3 in Fig. 13(a) and the unbonded region Ae in Fig. 13(b) may be reversed.

[0062] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0063] 1. Wafer Processing System 31 Wafer processing equipment 40 Control device 100 Chuck 103 Rotation mechanism 104 Horizontal movement mechanism 110 Laser Irradiation System 112 Lens Fw laser absorbing film P Pulse pitch Q Index Pitch S 2nd wafer T Polymer Wafer W First wafer

Claims

1. A substrate processing apparatus for processing a laminated substrate in which a first substrate and a second substrate are bonded together, comprising: a substrate holder for holding the laminated substrate; a laser irradiation unit that irradiates a laser light in a pulsed manner onto a laser absorption layer formed between the first substrate and the second substrate; a moving mechanism that moves the substrate holding unit and the laser irradiation unit relatively; A control unit that controls the laser irradiation unit and the movement mechanism, The control unit sets a pitch of the laser light irradiated onto the laser absorbing layer based on a thickness of the laser absorbing layer.

2. The moving mechanism includes: a rotation mechanism that rotates the substrate holding unit and the laser irradiation unit relative to each other; a horizontal movement mechanism for relatively moving the substrate holding unit and the laser irradiation unit in a horizontal direction, The substrate processing apparatus according to claim 1 , wherein the control unit sets a circumferential pitch and a radial pitch as the pitch of the laser light.

3. The substrate processing apparatus according to claim 1 , wherein the control unit sets a pitch of the laser light based on a thickness of the laser absorption layer so that a laser processing time of the laminated substrate is minimized.

4. The substrate processing apparatus according to claim 1 or 2, wherein the control unit sets a pitch of the laser light based on a thickness of the laser absorption layer so that a laser processing time for the laminated substrate becomes a laser processing time required for the substrate processing apparatus.

5. A substrate processing apparatus as described in claim 1 or 2, wherein the control unit performs control to irradiate the laser light from the laser irradiation unit to the laser absorption layer to expand the laser absorption layer.

6. A substrate processing method for irradiating a laser light onto a laser absorption layer formed between a first substrate and a second substrate in a laminated substrate formed by bonding the first substrate and the second substrate, the method comprising the steps of: setting a pitch of the laser light irradiated onto the laser absorbing layer based on a thickness of the laser absorbing layer; irradiating the laser absorption layer with the laser light so as to match the pitch of the laser light.

7. the pitch of the laser light includes a circumferential pitch and a radial pitch, a substrate holding unit that holds the laminated substrate and a laser irradiation unit that irradiates the laser light are rotated relative to each other so that the circumferential pitch is achieved, and the laser light is irradiated from the laser irradiation unit to the laser absorption layer; 7. The substrate processing method according to claim 6, wherein the laser light is irradiated from the laser irradiation unit to the laser absorption layer while the substrate holding unit and the laser irradiation unit are moved relatively in a horizontal direction so as to achieve the radial pitch.

8. 8. The substrate processing method according to claim 6, further comprising: setting a pitch of the laser light based on a thickness of the laser absorption layer so that a laser processing time of the laminated substrate is minimized.

9. 8. The substrate processing method according to claim 6, further comprising: setting a pitch of the laser light based on a thickness of the laser absorption layer so that a laser processing time for the laminated substrate is a laser processing time required for a substrate processing apparatus.

10. A substrate processing method as described in claim 6 or 7, wherein the laser absorption layer is irradiated with the laser light to cause the laser absorption layer to expand.

11. A method for manufacturing a laminated substrate in which a first substrate and a second substrate are bonded together, comprising the steps of: forming a laser absorbing layer between the first substrate and the second substrate, and bonding the first substrate and the second substrate to produce the laminated substrate; the laser absorption layer is irradiated with pulsed laser light after the first substrate and the second substrate are bonded to each other; A substrate manufacturing method comprising: setting a thickness of the laser absorption layer based on a pitch of the laser light irradiated onto the laser absorption layer.

12. the pitch of the laser light includes a circumferential pitch and a radial pitch, The substrate manufacturing method according to claim 11 , further comprising setting a thickness of the laser absorption layer based on the circumferential pitch and the radial pitch.

13. The method for manufacturing a substrate according to claim 11 or 12, wherein a pitch of the laser light is set so as to minimize a laser processing time of the laminated substrate.

14. The method for manufacturing a substrate according to claim 11 or 12, wherein a pitch of the laser light is set so that a laser processing time for the laminated substrate is equal to a required laser processing time.

15. A substrate manufacturing method as described in claim 11 or 12, wherein the laser absorption layer expands when irradiated with the laser light.

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