Substrate processing apparatus, substrate processing method, and substrate manufacturing method

Abstract

A substrate processing apparatus that processes a bonded substrate in which a first substrate and a second substrate are bonded together, the substrate processing apparatus including: a substrate holding portion that holds the bonded substrate; a laser irradiation portion that irradiates a laser in a pulse shape to a laser absorption layer formed between the first substrate and the second substrate; a moving mechanism that moves the substrate holding portion and the laser irradiation portion relative to each other; and a control portion that controls the laser irradiation portion and the moving mechanism, wherein the control portion sets an interval of the laser irradiated to the laser absorption layer based on a thickness of the laser absorption layer.

Description

Technical Field

[0001] This 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. The method includes the following steps: a heating step, in which a CO2 laser is irradiated from the back side of a semiconductor substrate to locally heat a stripping oxide film; and a transfer step, in which peeling occurs in the stripping oxide film and / or at the interface between the stripping oxide film and the semiconductor substrate, thereby transferring a semiconductor element to a transfer target substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-220749 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The technology disclosed herein improves the productivity of substrate processing for overlapping substrates formed by bonding a first substrate and a second substrate using laser.

[0008] Solution for solving the problem

[0009] One aspect of this disclosure is a substrate processing apparatus for processing an overlapping substrate formed by bonding a first substrate and a second substrate. The substrate processing apparatus includes: a substrate holding section for holding the overlapping substrate; a laser irradiation section for irradiating a laser in a pulsed manner onto a laser absorption layer formed between the first substrate and the second substrate; a moving mechanism for moving the substrate holding section and the laser irradiation section relative to each other; and a control section for controlling the laser irradiation section and the moving mechanism, wherein the control section sets the interval of the laser irradiated onto the laser absorption layer based on the thickness of the laser absorption layer.

[0010] The effects of the invention

[0011] According to this disclosure, the productivity of substrate processing for overlapping substrates formed by bonding a first substrate and a second substrate using a laser can be increased. Attached Figure Description

[0012] Figure 1 This is a side view showing an outline of the structure of overlapping wafers processed in a wafer processing system.

[0013] Figure 2 It is a top view schematically showing the outline of the structure of a wafer processing system.

[0014] Figure 3 This is a side view showing an outline of the structure of the wafer processing apparatus.

[0015] Figure 4 This is a top view showing an outline of the structure of the wafer processing apparatus.

[0016] Figure 5 This is an explanatory diagram showing the situation of irradiating a laser absorption film with laser light.

[0017] Figure 6 This is an explanatory diagram showing the situation of irradiating a laser absorption film with laser light.

[0018] Figure 7 This is an explanatory diagram showing the process of separating the first wafer from the second wafer.

[0019] Figure 8 This is an explanatory diagram regarding the irradiation interval of the laser irradiating the laser absorption film.

[0020] Figure 9 It is a graph showing the tendency of the relationship between the thickness of the laser absorption film and the pulse energy of the laser.

[0021] Figure 10 This is a graph showing the tendency of the relationship between the thickness of the laser absorption film and the productivity of wafer processing.

[0022] Figure 11 This is a table showing the correlation between the thickness of the laser absorption film and the laser irradiation interval.

[0023] Figure 12 This is an explanatory diagram showing the main wafer processing steps in the wafer processing system.

[0024] Figure 13 This is an explanatory diagram showing the main wafer processing steps in the wafer processing system. Detailed Implementation

[0025] In the semiconductor device manufacturing process, a device layer from the surface of the first substrate (such as a silicon substrate, semiconductor) is transferred to the second substrate to form an overlap substrate formed by bonding a first substrate and a second substrate. The first substrate has multiple electronic circuits and other devices formed on its surface. At this time, a process known as laser peeling is sometimes performed, for example, using a laser to peel the first substrate from the second substrate. In laser peeling, a laser is irradiated onto a laser-absorbing layer (such as an oxide film) formed between the first and second substrates, causing peeling at the interface between the two substrates.

[0026] The method described in Patent Document 1 is a manufacturing method for a semiconductor device using this laser-eluting technique. Patent Document 1 describes a method for stable laser processing by increasing the thickness of the oxide film to prevent changes in the characteristics of the semiconductor elements in the device layer, damage, etc. However, it does not consider improving the productivity of this laser processing, nor does it provide any related inspiration. Therefore, there is room for improvement in conventional laser processing.

[0027] The technology disclosed herein improves the productivity of substrate processing of overlapping substrates formed by bonding a first substrate and a second substrate using lasers. 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 this embodiment will be described with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, elements having substantially the same functional structure are labeled with the same reference numerals, thereby omitting repeated descriptions.

[0028] In the wafer processing system 1 described later in this embodiment, as... Figure 1 As shown, a superimposed wafer T, which is formed by bonding a first wafer W (serving as a first substrate) and a second wafer S (serving as a second substrate), is processed. Hereinafter, in the first wafer W, the surface bonded to the second wafer S is referred to as surface Wa, and the surface opposite to surface Wa is referred to as back surface Wb. Similarly, in the second wafer S, the surface bonded to the first wafer W is referred to as surface Sa, and the surface opposite to surface Sa is referred to as back surface Sb.

[0029] The first wafer W is, for example, a semiconductor wafer such as a silicon substrate. A lift-promoting film Fm, a laser-absorbing film Fw serving as a laser-absorbing layer, a device layer (not shown) including multiple devices, and a surface film Fe are stacked on the surface Wa of the first wafer W. For the lift-promoting film Fm, a film that is transparent to laser light from the laser irradiation system 110 described later, and whose adhesion between the lift-promoting film Fm and the first wafer W (silicon) is at least less than the adhesion between the lift-promoting film Fm and the laser-absorbing film Fw, such as a SiN film, is used. For the laser-absorbing film Fw, a film capable of absorbing laser light from the laser irradiation system 110 described later, such as an oxide film (SiO2 film, TEOS film), is used. For the surface film Fe, examples include oxide films (THOX film, SiO2 film, TEOS film), SiC film, SiCN film, or adhesives.

[0030] The second wafer S is, for example, a semiconductor wafer such as a silicon substrate. A device layer (not shown) including multiple devices is formed on the surface Sa of the second wafer S, and a surface film Fs is also formed in layers. Examples of surface films Fs include oxide films (THOX films, SiO2 films, TEOS films), SiC films, SiCN films, or adhesives. Furthermore, the surface film Fe of the first wafer W is bonded to the surface film Fs of the second wafer S.

[0031] like Figure 2 As shown, the wafer processing system 1 has a structure that integrates the infeed / outfeed block 10, the transport block 20, and the processing block 30 into one unit. The infeed / outfeed block 10 and the processing block 30 are disposed around the transport block 20. Specifically, the infeed / outfeed block 10 is disposed on the negative Y-axis side of the transport block 20. The wafer processing apparatus 31, described later, of the processing block 30 is disposed on the negative X-axis side of the transport block 20, and the cleaning apparatus 32, described later, is disposed on the positive X-axis side of the transport block 20.

[0032] The loading / unloading block 10, for example, loads and unloads boxes Ct capable of accommodating multiple overlapping wafers T, boxes Cw capable of accommodating multiple first wafers W, and boxes Cs capable of accommodating multiple second wafers S between the loading / unloading block 10 and the outside. A box mounting stage 11 is provided on the loading / unloading block 10. In the illustrated example, multiple, for example, three boxes Ct, Cw, and Cs are freely mounted on the box mounting stage 11 in a row along the X-axis direction. Furthermore, the number of boxes Ct, Cw, and Cs mounted on the box mounting stage 11 is not limited to this embodiment and can be arbitrarily determined.

[0033] A wafer transport device 22 is provided on the transport block 20, configured to move freely on a transport path 21 extending along the X-axis. The wafer transport device 22 has, for example, two transport arms 23, 23 that hold and transport overlapping wafers T, first wafer W, and second wafer S. Each transport arm 23 is configured to move freely in the horizontal and vertical directions, and about the horizontal and vertical axes. Furthermore, the structure of the transport arm 23 is not limited to this embodiment, and any structure can be adopted. Moreover, the wafer transport device 22 is configured to transport overlapping wafers T, first wafer W, and second wafer S to the cassettes Ct, Cw, Cs of the cassette stage 11, the wafer processing apparatus 31 described later, and the cleaning apparatus 32.

[0034] The processing block 30 includes a wafer processing apparatus 31 and a cleaning apparatus 32. The wafer processing apparatus 31 irradiates a laser onto the laser absorption film Fw of the first wafer W to peel off the first wafer W from the second wafer S. The structure of the wafer processing apparatus 31 will be described later.

[0035] The cleaning apparatus 32 cleans the outermost surface (the surface of the release facilitator film Fm) of the second wafer S separated from the wafer processing apparatus 31 on the surface Sa side. For example, the brush is brought into contact with the surface of the release facilitator film Fm to brush the surface. Alternatively, pressurized cleaning fluid can be used for surface cleaning. Furthermore, the cleaning apparatus 32 may also have a structure that cleans the back side Sb of the second wafer S together with the surface Sa side.

[0036] The wafer processing system 1 described above includes a control device 40, which serves as a control unit. The control device 40 is, for example, a computer, and includes a program storage unit (not shown). This program storage unit stores a program for controlling the processing of the overlapping wafers T in the wafer processing system 1. Additionally, the program storage unit also stores a program for controlling the operation of the drive systems of the various processing devices, transport devices, etc., described above to achieve the wafer processing described later in the wafer processing system 1. Furthermore, the above-mentioned programs can also be recorded in a storage medium H that can be read by a computer and installed from that storage medium H into the control device 40.

[0037] Next, the wafer processing apparatus 31 described above will be explained.

[0038] like Figure 3 and Figure 4 As shown, the wafer processing apparatus 31 has a holder 100 that serves as a substrate holding portion, holding overlapping wafers T on its upper surface. The holder 100 adsorbs and holds the back side Sb of the second wafer S.

[0039] The retainer 100 is supported on the sliding platform 102 via an air bearing 101. A rotating mechanism 103 is provided on the lower surface of the sliding platform 102. The rotating mechanism 103 may have a built-in motor as a drive source. The retainer 100 is configured to rotate freely about the θ axis (vertical axis) via the air bearing 101 through the rotating mechanism 103. The sliding platform 102 is configured to move along a guide rail 105 extending in the Y-axis direction via a horizontal moving mechanism 104 provided on its lower surface. The guide rail 105 is provided on the base 106. Furthermore, there is no particular limitation on the drive source of the horizontal moving mechanism 104; for example, a linear motor can be used. In this embodiment, the rotating mechanism 103 and the horizontal moving mechanism 104 described above correspond to the "moving mechanism" involved in the present disclosure.

[0040] A laser irradiation system 110, serving as a laser irradiation unit, is disposed above the holder 100. The laser irradiation system 110 includes a laser head 111 and a lens 112 serving as the laser irradiation unit. The lens 112 may also be configured to be freely raised and lowered via a lifting mechanism (not shown).

[0041] The laser head 111 has a laser oscillator (not shown) that oscillates the laser in a pulsed manner. That is, the laser irradiating the superimposed wafer T held in the holder 100 from the laser irradiation system 110 is a so-called pulsed laser, whose power repeats between 0 (zero) and its maximum value. Furthermore, in this embodiment, the laser is a CO2 laser, and the wavelength of the CO2 laser is, for example, 8.9 μm to 11 μm. In addition, the laser head 111 may also have devices other than a laser oscillator, such as an amplifier.

[0042] Lens 112 is a cylindrical component that irradiates the superimposed wafer T held in the holder 100 with laser light. The laser light emitted from the laser irradiation system 110 passes through the first wafer W, irradiates the laser absorption film Fw, and is absorbed.

[0043] like Figure 4 As shown, a transport pad 120 serving as a stripping processing unit is provided above the holder 100. The transport pad 120 is configured to move freely up and down via a lifting mechanism (not shown). Furthermore, the transport pad 120 has an adsorption surface for the first wafer W. The transport pad 120 transports the first wafer W between the holder 100 and the transport arm 23. Specifically, after the holder 100 is moved below the transport pad 120 (to the junction with the transport arm 23), the transport pad 120 adsorbs and holds the back surface Wb of the first wafer W to strip it from the second wafer S. Then, the stripped first wafer W is transferred from the transport pad 120 to the transport arm 23 and removed from the wafer processing apparatus 31.

[0044] Furthermore, in this embodiment, the laser irradiation unit (laser irradiation system 110) and the stripping processing unit (transfer pad 120) are disposed inside the same wafer processing apparatus 31, but the laser irradiation apparatus and the stripping processing unit may also be disposed as separate processing apparatuses.

[0045] Next, the wafer processing performed using the wafer processing system 1 configured as described above will be explained. Furthermore, in this embodiment, in a bonding device (not shown) outside the wafer processing system 1, the first wafer W and the second wafer S are bonded to pre-form an overlapping wafer T.

[0046] First, the box Ct containing multiple overlapping wafers T is placed on the box mounting stage 11 of the transfer block 10.

[0047] Next, the overlapping wafer T is removed from the cassette Ct by the wafer transfer device 22 and transferred to the wafer processing apparatus 31. In the wafer processing apparatus 31, the overlapping wafer T is transferred from the transfer arm 23 to the holder 100 and held there. Then, the holder 100 is moved to a processing position by the horizontal movement mechanism 104. This processing position is a position where laser light can be irradiated onto the overlapping wafer T (laser absorption film Fw) from the laser irradiation system 110.

[0048] Next, as Figure 5 and Figure 6 As shown, a laser L is pulsed onto the laser absorption film Fw from the laser irradiation system 110. The laser L passes through the first wafer W and the release facilitating film Fm from the back side Wb of the first wafer W, and is absorbed at the laser absorption film Fw. At this time, the laser absorption film Fw accumulates energy due to the absorption of the laser L, thereby increasing its temperature and expanding. The shear stress generated by the expansion of the laser absorption film Fw is also transmitted to the release facilitating film Fm. Moreover, since the adhesion force of the release facilitating film Fm to the first wafer W is smaller than the adhesion force of the release facilitating film Fm to the laser absorption film Fw, peeling occurs at the interface between the first wafer W and the release facilitating film Fm.

[0049] When laser L is irradiated onto the laser absorption film Fw, the holder 100 (overlapping wafer T) is rotated by the rotation mechanism 103, and the holder 100 is moved along the Y-axis by the horizontal movement mechanism 104. Thus, laser L irradiates the laser absorption film Fw from the radially outer side towards the inner side, resulting in a spiral irradiation from the outer side to the inner side. Furthermore, Figure 6 The black arrows shown indicate the direction of rotation of retainer 100.

[0050] The laser L can also be irradiated in a concentric circle in a ring shape. Alternatively, the laser L can irradiate the laser absorption film Fw from the radially inward side outward. Alternatively, after repeatedly irradiating the laser L in a fan-shaped pattern with the center of the laser absorption film Fw as the apex, the holder 100 can be moved to further irradiate the un-irradiated portions of the laser L in a fan-shaped pattern, thereby irradiating the entire laser absorption film Fw. Furthermore, the holder 100 can be moved to irradiate the laser L in a linear pattern, thereby irradiating the entire laser absorption film Fw.

[0051] In this embodiment, when the laser L is irradiated onto the laser absorption film Fw, the holder 100 is rotated, but the lens 112 can also be moved to rotate the lens 112 relative to the holder 100. Alternatively, the holder 100 can be moved along the Y-axis, but the lens 112 can also be moved along the Y-axis.

[0052] In this manner, in the wafer processing apparatus 31, the laser absorption film Fw is irradiated with laser L in a pulsed pattern. Furthermore, by oscillating the laser L in a pulsed pattern, the peak power (maximum intensity of the laser) can be increased, thereby generating peeling at the interface between the first wafer W and the peeling promotion film Fm. As a result, the first wafer W can be properly peeled from the second wafer S.

[0053] Furthermore, in this embodiment, the circumferential interval (pulse pitch) and radial interval (index pitch) of the laser L irradiating the laser absorption film Fw are set based on the thickness of the laser absorption film Fw. The method for setting the pulse pitch and index pitch will be described later.

[0054] After irradiating the laser absorption film Fw with laser L as described above, the holder 100 is then moved to the junction position by the horizontal moving mechanism 104. Then, as... Figure 7 As shown in (a), the back surface Wb of the first wafer W is held in place by the transport pad 120. Then, as... Figure 7 As shown in (b), with the first wafer W held in place by the transport pad 120, the transport pad 120 is raised to peel the first wafer W from the release facilitator film Fm. At this time, as described above, peeling occurs at the interface between the first wafer W and the release facilitator film Fm due to irradiation by the laser L, thus allowing the first wafer W to be peeled from the release facilitator film Fm without applying a large load. Then, the device layer of the first wafer W is transferred to the second wafer S. Alternatively, when the transport pad 120 is raised, it can also be rotated about a vertical axis to peel the first wafer W.

[0055] The first wafer W to be stripped is transferred from the transfer pad 120 to the transfer arm 23 of the wafer transfer device 22 and then to the cassette Cw of the cassette stage 11. Alternatively, the first wafer W removed from the wafer processing device 31 can also be transferred to the cleaning device 32 before being transferred to the cassette Cw, where its stripping surface, i.e., surface Wa, is cleaned. In this case, the transfer can also be performed by flipping the first wafer W between its surface and back side using the transfer pad 120 before transferring it to the transfer arm 23.

[0056] On the other hand, the second wafer S held in the holder 100 is transferred to the transfer arm 23 and then to the cleaning apparatus 32. In the cleaning apparatus 32, the outermost surface (the surface of the release facilitator film Fm) of the peeling surface, i.e., the surface Sa side, is brushed. Furthermore, in the cleaning apparatus 32, the back surface Sb of the second wafer S can also be cleaned together with the surface of the release facilitator film Fm. Alternatively, separate cleaning units can be provided for cleaning the surface of the release facilitator film Fm and the back surface Sb of the second wafer S, respectively.

[0057] Then, the second wafer S, which has undergone all processing, is transferred to the cassette Cs of the cassette stage 1 by the wafer transfer device 22. In this way, a series of wafer processing in the wafer processing system 1 is completed.

[0058] Next, the laser L is irradiated onto the laser absorption film Fw in the wafer processing apparatus 31. Figure 8 The method for setting the irradiation interval (pulse spacing P) for the circumferential laser L and the irradiation interval (gradient spacing Q) for the radial laser L is explained.

[0059] First, such as Figure 9 As shown, the inventors increased the thickness of the laser absorption film Fw (SiO2 film) to ( Figure 9 The pulse energy of laser L required to peel the first wafer W from the second wafer S was investigated under the condition of variation of the horizontal axis. Figure 9 (Vertical axis). When the thickness of the laser absorption film Fw is small, the volume of absorbed pulse energy is small and the absorption efficiency is low, thus the pulse energy required for stripping increases. On the other hand, when the thickness of the laser absorption film Fw is large, the pulse energy required for stripping decreases.

[0060] Next, as Figure 10 As shown, the inventors increased the thickness of the laser absorption film Fw (SiO2 film) to ( Figure 10 The productivity of wafer processing was investigated under the condition of changes in the horizontal axis. Figure 10 (Vertical axis). As mentioned above, when the thickness of the laser absorption film Fw is small, the pulse energy required for stripping increases. In this case, to increase the pulse energy, the pulse frequency of the laser L needs to be reduced, thus decreasing the wafer processing productivity. On the other hand, when the laser absorption film Fw is large, the pulse energy required for stripping is small, allowing the pulse frequency of the laser L to be increased, thus improving the wafer processing productivity.

[0061] As mentioned above, the thickness of the laser absorption film Fw is correlated with the wafer processing productivity. Furthermore, through further careful research, the inventors discovered that, as... Figure 11 As shown, the thickness of the laser absorption film Fw (SiO2 film) used to enable peeling is correlated with the pulse spacing P and indexing spacing Q of the laser L. That is, the first wafer W can be peeled from the second wafer S based on the thickness of the laser absorption film Fw. For example, in... Figure 11 Within the range of the pulse spacing P and the indexing spacing Q of the shaded area, the first wafer W can be peeled off from the second wafer S. Furthermore, in... Figure 11 The example shown is the case where the pulse spacing P and the indexing spacing Q are the same, but these pulse spacing P and indexing spacing Q can also be different.

[0062] The method for setting the pulse spacing P and the indexing spacing Q in this embodiment is based on the above insights, and the pulse spacing P and the indexing spacing Q are set based on the thickness of the laser absorption film Fw.

[0063] First, the thickness of the laser absorption film Fw is obtained. The thickness of the laser absorption film Fw can be obtained through the wafer processing apparatus 31, or it can be obtained beforehand outside the wafer processing apparatus 31. Furthermore, there is no particular limitation on the method for obtaining the thickness of the laser absorption film Fw; for example, it can be measured directly or indirectly using a sensor, or it can be obtained by photographing the superimposed wafer T using a camera. Then, the thickness of the laser absorption film Fw obtained in this way is output to the control device 40.

[0064] In the control device 40, the pulse spacing P and the indexing spacing Q are set based on the obtained thickness of the laser absorption film Fw. For example, the pulse spacing P and the indexing spacing Q can also be set in a manner that minimizes the processing time for wafer processing using laser (i.e., the laser processing time in this disclosure) while maximizing productivity. For example, in Figure 11 In the example shown, the pulse pitch P and indexing pitch Q are set to the maximum possible peeling pitch based on the thickness of the laser absorption film Fw. In this case, wafer processing productivity is maximized, thereby improving productivity. Furthermore, the pulse pitch P and indexing pitch Q can be the same as described above, or they can be different.

[0065] Alternatively, the pulse pitch P and indexing pitch Q can be set in a way that makes the wafer processing time (productivity) the processing time (productivity) required by the wafer processing apparatus 31. In this case, the wafer processing productivity can be ensured, and the apparatus capability of the wafer processing apparatus 31 can be maximized.

[0066] As described above, according to this embodiment, the pulse spacing P and indexing spacing Q of the laser L are set based on the thickness of the laser absorption film Fw, thus enabling appropriate control of the wafer processing productivity.

[0067] Next, the method for manufacturing the overlapping wafer T based on the discovery that there is a correlation between the thickness of the laser absorption film Fw and the pulse spacing P and indexing spacing Q of the laser L will be described.

[0068] In a bonding apparatus (not shown) outside the wafer processing system 1, a first wafer W and a second wafer S are bonded to manufacture a superimposed wafer T. At this time, a lift-promoting film Fm, a laser absorption film Fw, a device layer (not shown), and a surface film Fe are stacked on the surface Wa of the first wafer W. Additionally, a device layer (not shown) and a surface film Fs are stacked on the surface Sa of the second wafer S. Furthermore, the surface film Fe of the first wafer W is bonded to the surface film Fs of the second wafer S.

[0069] The thickness of the laser absorption film Fw is set based on the pulse spacing P and indexing spacing Q of the laser L irradiating the laser absorption film Fw in the wafer processing apparatus 31 after the overlapping wafer T has been manufactured. That is, as described above, based on the pulse spacing P and indexing spacing Q set according to the wafer processing time (productivity) in the wafer processing apparatus 31, for example... Figure 11 The correlation shown is used to set the thickness of the laser absorption film Fw.

[0070] As described above, according to this embodiment, the thickness of the laser absorption film Fw can be optimally set based on the pulse spacing P and the indexing spacing Q of the laser L, thus enabling appropriate control of the wafer processing productivity in the wafer processing apparatus 31.

[0071] Furthermore, in the above embodiments, when laser L is irradiated onto the laser absorption film Fw in the overlapping wafer T to peel off the first wafer W from the second wafer S, i.e., when laser peeling is performed, the pulse spacing P and indexing spacing Q setting method of this disclosure are applied, but the laser processing to which this is applied is not limited to this.

[0072] For example, such as Figure 12 As shown, when removing the peripheral portion We of the first wafer W in the overlapping wafer T, i.e., performing so-called edge trimming, the pulse pitch P and indexing pitch setting method of this disclosure can also be applied. Furthermore, the peripheral portion We of the first wafer W is, for example, a radial range of 0.5 mm to 3 mm from the outer end of the first wafer W.

[0073] Specifically, such as Figure 12 As shown in (a), a laser (e.g., a YAG laser) is irradiated into the interior of a first wafer W to form a peripheral modification layer M1 and a segmentation modification layer M2. The peripheral modification layer M1 is formed in a ring shape on concentric circles of the first wafer W. The segmentation modification layer M2 is formed to extend radially from the peripheral modification layer M1.

[0074] After that, as Figure 12 As shown in (b), a laser (e.g., a CO2 laser) is pulsed onto the laser absorption film Fw at the position corresponding to the peripheral portion We to form an unbonded region Ae where the bonding strength between the first wafer W and the second wafer S decreases.

[0075] After that, as Figure 12 As shown in (c), the peripheral portion We of the first wafer W is removed, i.e., edge trimming. At this time, the peripheral portion We is peeled off from the center of the first wafer W using the peripheral modification layer M1 as a base point, and the peripheral portion We is completely peeled off from the second wafer S using the unbonded region Ae as a base point. Furthermore, the removed peripheral portion We is fragmented using the dividing modification layer M2 as a base point.

[0076] In this embodiment, such as Figure 12 As shown in (b), when a laser is irradiated onto the laser absorption film Fw, the pulse spacing P and indexing spacing Q of the laser are set based on the laser absorption film Fw in the same way as in the above embodiment. As a result, the same effect as in the above embodiment can be achieved, namely, the wafer processing productivity can be improved.

[0077] For example, such as Figure 13 As shown, when an inner surface modification layer M3, which serves as a thinning base point for the first wafer W, is formed inside the first wafer W, and the peripheral portion We is integrally removed from the back side Wb side of the first wafer W, the method for setting the pulse pitch P and the indexing pitch Q disclosed herein can also be applied.

[0078] Specifically, such as Figure 13 As shown in (a), a laser is irradiated into the interior of a first wafer W, thereby forming a peripheral modification layer M1 and an interior surface modification layer M3 in sequence. The interior surface modification layer M3 is formed to extend along the surface direction within the interior of the first wafer W.

[0079] After that, as Figure 13 As shown in (b), an unbonded region Ae is formed by irradiating the laser absorption film Fw at the position corresponding to the peripheral portion We with a pulsed laser (e.g., a CO2 laser).

[0080] After that, as Figure 13 As shown in (c), the first wafer W is thinned with the inner surface modification layer M3 as the base point, and the peripheral portion We is integrally peeled off and removed with the peripheral modification layer M1 and the unbonded region Ae as the base points.

[0081] In this embodiment, such as Figure 13 As shown in (b), when irradiating the laser absorption film Fw with laser light, the pulse spacing P and the indexing spacing Q of the laser light are set based on the laser absorption film Fw in the same way as in the above embodiment. As a result, the same effect as in the above embodiment can be achieved, namely, the wafer processing productivity can be improved. Furthermore, in this embodiment, a device layer is formed on the surface Wa of the first wafer W, but the technology of this disclosure can also be applied when performing the same processing on, for example, an SOI wafer without a device layer.

[0082] In addition, in the above Figure 12 In the example shown, Figure 12 The formation of the peripheral modified layer M1 and the segmented modified layer M2 in (a) and Figure 12 The order in which the unjoined region Ae in (b) is formed can also be reversed. Similarly, in the above... Figure 13 In the example shown, Figure 13 The formation of the peripheral modified layer M1 and the internal surface modified layer M3 in (a) and Figure 13 The order in which the unjoined region Ae of (b) is formed can also be reversed.

[0083] It should be considered that the embodiments disclosed herein are illustrative and not restrictive in all respects. The above embodiments may also be omitted, substituted, or modified in various ways without departing from the appended claims and their spirit.

[0084] Explanation of reference numerals in the attached figures

[0085] 1: Wafer processing system; 31: Wafer processing device; 40: Control device; 100: Holder; 103: Rotation mechanism; 104: Horizontal movement mechanism; 110: Laser irradiation system; 112: Lens; Fw: Laser absorption film; P: Pulse pitch; Q: Indexing pitch; S: Second wafer; T: Overlapping wafer; W: First wafer.

Claims

1. A substrate processing apparatus for processing an overlapping substrate formed by bonding a first substrate and a second substrate, the substrate processing apparatus comprising: A substrate holding portion that holds the overlapping substrate; A laser irradiation section that irradiates a laser absorption layer formed between the first substrate and the second substrate with a pulsed laser. A moving mechanism that moves the substrate holding portion and the laser irradiation portion relative to each other; and The control unit controls the laser irradiation unit and the moving mechanism. in, The control unit sets the spacing of the lasers irradiating the laser absorption layer based on the thickness of the laser absorption layer, and the spacing of the lasers is the distance between adjacent laser irradiation positions.

2. The substrate processing apparatus according to claim 1, characterized in that, The mobile mechanism has: A rotating mechanism that causes the substrate holding portion and the laser irradiation portion to rotate relative to each other; and A horizontal moving mechanism that causes the substrate holding part and the laser irradiation part to move relative to each other in a horizontal direction. The control unit sets a circumferential spacing and a radial spacing as the spacing of the laser.

3. The substrate processing apparatus according to claim 1 or 2, characterized in that, The control unit sets the laser spacing based on the thickness of the laser absorption layer in a manner that minimizes the laser processing time of the overlapping substrate.

4. The substrate processing apparatus according to claim 1 or 2, characterized in that, The control unit sets the laser spacing based on the thickness of the laser absorption layer, so that the laser processing time of the overlapping substrate becomes the laser processing time required by the substrate processing apparatus.

5. A substrate processing method, wherein a laser is irradiated onto a laser-absorbing layer formed between the first substrate and the second substrate in an overlapping substrate formed by bonding a first substrate and a second substrate, the substrate processing method comprising: The spacing of the laser beam irradiating the laser absorption layer is set based on the thickness of the laser absorption layer; as well as The laser is irradiated onto the laser absorption layer at a distance that is the distance between adjacent laser irradiation positions.

6. The substrate processing method according to claim 5, characterized in that, The spacing of the laser beams includes circumferential spacing and radial spacing. The laser is irradiated from the laser irradiation section toward the laser absorption layer while the substrate holding portion that holds the overlapping substrate is rotated relative to the laser irradiation section that irradiates the laser, such that the circumferential spacing is specified. The laser is irradiated from the laser irradiation section onto the laser absorption layer while the substrate holding portion is moved horizontally relative to the laser irradiation section in such a radially spaced manner.

7. The substrate processing method according to claim 5 or 6, characterized in that, The laser spacing is set based on the thickness of the laser absorption layer in a manner that minimizes the laser processing time of the overlapping substrate.

8. The substrate processing method according to claim 5 or 6, characterized in that, The laser spacing is set based on the thickness of the laser absorption layer so that the laser processing time of the overlapping substrate is the laser processing time required by the substrate processing apparatus.

9. A method for manufacturing a substrate, used to manufacture an overlapping substrate formed by bonding a first substrate and a second substrate, wherein in the substrate manufacturing method, A laser absorption layer is formed between the first substrate and the second substrate, and the first substrate and the second substrate are bonded together to manufacture the overlapping substrate. The laser absorption layer is irradiated with laser in a pulsed manner after the first substrate and the second substrate are bonded. The thickness of the laser absorption layer is determined based on the spacing of the lasers irradiating the laser absorption layer, where the laser spacing is the distance between adjacent laser irradiation positions.

10. The substrate manufacturing method according to claim 9, characterized in that, The spacing of the laser beams includes circumferential spacing and radial spacing. The thickness of the laser absorption layer is determined based on the circumferential spacing and the radial spacing.

11. The substrate manufacturing method according to claim 9 or 10, characterized in that, The laser spacing is set to minimize the laser processing time of the overlapping substrate.

12. The substrate manufacturing method according to claim 9 or 10, characterized in that, The laser spacing is set such that the laser processing time of the overlapping substrate becomes the required laser processing time.

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