Substrate processing system, substrate processing method, and device structure

Abstract

A substrate processing system for processing a polymer substrate formed by laminating a first substrate, an interface layer that includes at least a laser-absorbing layer, and a second substrate, wherein: the substrate processing system comprises a laser radiation unit that irradiates the laser-absorbing layer with pulsed laser light, and a control unit; and the control unit allows the first substrate or the interface layer to expand due to heat produced by irradiating the laser-absorbing layer with the laser light and controls irradiation of the laser light in the laser radiation unit such that peeling occurs at the interface between the first substrate and the laser-absorbing layer, or at the interface between the interface layer and the laser-absorbing layer, due to stress produced by the expansion.

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing system, a substrate processing method, and a device structure. [Background technology]

[0002] Patent Document 1 discloses a method for transferring a semiconductor element formed on a surface of a semiconductor substrate, the semiconductor element being transferred to a destination substrate. The method described in Patent Document 1 includes a step of irradiating the back surface of the semiconductor substrate with light to locally heat the exfoliation oxide film, and a step of thermally expanding the exfoliation oxide film and / or at the interface between the exfoliation oxide film and the semiconductor substrate to cause exfoliation, thereby transferring the semiconductor element to the destination substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2007-220749 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique according to the present disclosure appropriately separates the first substrate and the laser absorption layer in a laminated substrate in which the laser absorption layer is formed at the interface between the first substrate and the second substrate. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate processing system for processing a laminated substrate formed by stacking a first substrate, an interface layer including at least a laser absorbing layer, and a second substrate, the system including: a laser irradiation unit that irradiates the laser absorption layer with laser light in pulses; and a control unit, wherein the control unit controls the irradiation of the laser light by the laser irradiation unit so that the first substrate or the interface layer expands due to heat generated by irradiating the laser absorption layer with the laser light, and stress generated by the expansion causes delamination at the interface between the first substrate and the laser absorption layer, or at the interface between the interface layer and the laser absorption layer. [Effects of the Invention]

[0006] According to the present disclosure, in a laminated substrate in which a laser absorption layer is formed at the interface between a first substrate and a second substrate, the first substrate and the laser absorption layer can be appropriately separated. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a side view showing a configuration example of an overlapping wafer according to an embodiment. [Figure 2] 1 is a plan view showing an outline of the configuration of a wafer processing system according to an embodiment; [Figure 3] 1 is a plan view showing an outline of the configuration of a laser irradiation device according to an embodiment; [Figure 4] 1 is a side view showing an outline of the configuration of a laser irradiation device according to an embodiment. [Figure 5] FIG. 4 is a side view illustrating an operation of the separation device according to the embodiment. [Figure 6] FIG. 10 is an explanatory diagram showing the state of the overlapped wafer irradiated with laser light. [Figure 7] FIG. 2 is a flow chart showing the main steps of wafer processing in the wafer processing system. [Figure 8] 10 is an explanatory diagram showing the diffusion of heat generated in the overlapping wafer. FIG. [Figure 9] FIG. 4 is an explanatory diagram showing the state of expansion of the first wafer due to irradiation with laser light. [Figure 10] FIG. 10 is an explanatory diagram showing the state of the overlapped wafer irradiated with laser light. [Figure 11] FIG. 10 is an explanatory view showing how the first wafer and the laser absorption layer are peeled off. [Figure 12] FIG. 10 is an explanatory view showing how the first wafer and the laser absorption layer are peeled off. [Figure 13] FIG. 3 is an explanatory diagram showing a modified layer formed on a first substrate. [Figure 14] FIG. 3 is an explanatory diagram showing a modified layer formed on a first substrate. [Figure 15] 10 is an explanatory diagram showing how the peeling-promoting layer and the laser absorbing layer are peeled off. FIG. [Figure 16] FIG. 10 is a flowchart showing main steps of wafer processing according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the manufacturing process of semiconductor devices, a device layer formed on the surface of a first semiconductor substrate (hereinafter referred to as "wafer") is transferred to a second wafer in a bonded wafer. The transfer of the device layer to the second wafer is performed by irradiating a laser light onto a laser absorption layer formed between the first wafer and the device layer, and peeling the first wafer from the laser absorption layer.

[0009] The transfer of the device layer is performed, for example, by the method disclosed in Patent Document 1. That is, after irradiating a peeling oxide film (laser absorption layer) formed on a semiconductor substrate with light (laser light) to locally heat the peeling oxide film, a modified film is formed at the interface between the peeling oxide film and the semiconductor substrate, and peeling occurs using the modified film as a base point to transfer the semiconductor element to a destination substrate.

[0010] As a result of intensive investigations, the present inventors have come up with a new method for causing delamination at the interface between the first wafer and the laser absorbing layer. Specifically, instead of irradiating the laser absorbing layer with laser light to thermally expand the laser absorbing layer and causing delamination, the present inventors have discovered a method for causing delamination at the interface between the first wafer and the laser absorbing layer by irradiating the laser absorbing layer with laser light and expanding the first wafer by the heat generated thereby.

[0011] The technology disclosed herein appropriately separates a first substrate and a laser absorption layer in a laminated substrate in which the laser absorption layer is formed at the interface between the first substrate and the second substrate. Hereinafter, a wafer processing system as a substrate processing system and a wafer processing method as a substrate processing method according to this 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 designated by the same reference numerals, and redundant description will be omitted.

[0012] 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 formed by bonding a first wafer W and a second wafer S, as shown in Fig. 1. Hereinafter, the surface of the first wafer W that is bonded to the second wafer S will be referred to as the front surface Wa, and the surface opposite the front surface Wa will be referred to as the back surface Wb. Similarly, the surface of the second wafer S that is bonded to the first wafer W will be referred to as the front surface Sa, and the surface opposite the front surface Sa will be referred to as the back surface Sb.

[0013] The first wafer W as the first substrate is a semiconductor wafer such as a silicon substrate. In one embodiment, the first wafer W has a substantially circular disk shape. A laminated film formed by stacking multiple films is formed on the surface Wa of the first wafer W. The laminated film includes, in order from the surface Wa side, a laser absorption layer P, a device layer Dw, and a surface film Fw. The device layer Dw includes multiple devices. Examples of the surface film Fw include an oxide film (THOX film, SiO2 film, TEOS film), a SiC film, a SiCN film, or an adhesive. The first wafer W is bonded to the second wafer S via this surface film Fw. Note that the device layer Dw and the surface film Fw may not be formed on the surface Wa. In this case, the laser absorption layer P is formed on the second wafer S side, and the device layer Ds on the second wafer S side, which will be described later, is transferred to the first wafer W side.

[0014] The laser absorbing layer P absorbs the laser light irradiated from the laser irradiation unit 110, as will be described later. The laser absorbing layer P may be made of, for example, an oxide film (SiO2 film, TEOS film), but is not particularly limited as long as it absorbs laser light. The laser absorbing layer P is formed, for example, by a CVD (Chemical Vapor Deposition) process outside the wafer processing system 1, which will be described later. The composition of the oxide film (SiO2 film, TEOS film) serving as the laser absorbing layer P can be changed as desired depending on the type and mixture ratio of the processing gas used in the CVD process. Details of the composition of the laser absorbing layer P used in wafer processing according to the technology of the present disclosure will be described later.

[0015] The second wafer S serving as the second substrate is a semiconductor wafer such as a silicon substrate. A laminated film is formed on the surface Sa of the second wafer S. The laminated film has a device layer Ds and a surface film Fs, in this order, from the surface Sa side. The device layer Ds and the surface film Fs are the same as the device layer Dw and the surface film Fw of the first wafer W, respectively. The surface film Fw of the first wafer W and the surface film Fs of the second wafer S are bonded together. Note that the device layer Ds and the surface film Fs may not be formed on the surface Sa.

[0016] In the technology of the present disclosure, the laminated films formed at the interface between the first wafer W and the second wafer S, specifically the laser absorption layer P, the device layers Dw, Ds, and the surface films Fw, Fs, may be collectively referred to as the "interface layer." In the technology of the present disclosure, the interface layer includes at least the laser absorption layer P. The type of laminated film formed at the interface between the first wafer W and the second wafer S is not limited to the example shown in Fig. 1. For example, the laminated film may include a "peeling-promoting film" (described later) for properly peeling the first wafer W from the laser absorption layer P. In this case, the above-mentioned interface layer includes the peeling-promoting film.

[0017] 2, the wafer processing system 1 has a configuration in which a load / unload block 10, a transfer block 20, and a processing block 30 are integrally connected. The load / unload block 10 and the processing block 30 are provided around the transfer block 20. Specifically, the load / unload block 10 is disposed on the negative Y-axis side of the transfer block 20. A laser irradiation device 31 (described later) and a separation device 32 (described later) of the processing block 30 are disposed on the negative X-axis side of the transfer block 20, and a first cleaning device 33 (described later) and a second cleaning device 34 (described later) are disposed on the positive X-axis side of the transfer block 20.

[0018] The carry-in / out block 10 carries in and out cassettes Ct, Cw, and Cs, each capable of accommodating a plurality of overlapping wafers T, a plurality of first wafers W, and a plurality of second wafers S, for example, between the outside and the block. A cassette mounting table 11 is provided in the carry-in / out block 10. In the illustrated example, the cassette mounting table 11 is capable of mounting 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 that in this embodiment and can be determined arbitrarily.

[0019] 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, or the second wafer S. Each transfer arm 23 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. Note that the configuration of the transfer arm 23 is not limited to this embodiment and may have any configuration. The wafer transfer device 22 is configured to transfer the overlapped wafer T, the first wafer W, or the second wafer S to the cassettes Ct, Cw, and Cs on the cassette mounting table 11, the laser irradiation device 31, the separation device 32, the first cleaning device 33, and the second cleaning device 34.

[0020] The processing block 30 has a laser irradiation device 31, a separation device 32, a first cleaning device 33, and a second cleaning device 34. In one example, the laser irradiation device 31 and the separation device 32 are stacked on the negative side of the X-axis of the transport block 20. The first cleaning device 33 and the second cleaning device 34 are stacked on the positive side of the X-axis of the transport block 20. However, the number and arrangement of the laser irradiation device 31, the separation device 32, the first cleaning device 33, and the second cleaning device 34 are not limited to this.

[0021] The laser irradiation device 31 irradiates the inside of the overlapped wafer T, more specifically, the laser absorbing layer P formed on the surface Wa of the first wafer W, with laser light to reduce the bonding strength at the interface between the first wafer W and the laser absorbing layer P. In the technology of the present disclosure, this interface with reduced bonding strength inside the overlapped wafer T (in this embodiment, the interface between the first wafer W and the laser absorbing layer P) may be referred to as a "separation surface."

[0022] 3, a delivery position A1 and a processing position A2 are set inside the laser irradiation device 31. The delivery position A1 is a position where the overlapped wafer T can be delivered from the transfer arm 23 to a chuck 100 (described later) and where an image of the overlapped wafer T (laser absorbing layer P) can be captured by a camera 120 (described later). The processing position A2 is a position where the overlapped wafer T (laser absorbing layer P) can be irradiated with laser light from a laser irradiation unit 110 (described later).

[0023] 3 and 4, the laser irradiation device 31 has a chuck 100 as a substrate holder that holds the overlapped wafer T on its upper surface. The chuck 100 has a holding surface for the overlapped wafer T on its upper surface, and adsorbs and holds the entire back surface Sb of the second wafer S or a radially inner portion of the back surface Sb. The chuck 100 is, for example, an electrostatic chuck (ESC) or a vacuum chuck. The chuck 100 is provided with lifting pins (not shown) for supporting and elevating the overlapped wafer T from below. The lifting pins are inserted into through holes (not shown) formed through the chuck 100 and are configured to be able to move up and down.

[0024] The chuck 100 is supported by a slider table 102 via an air bearing 101. A rotation mechanism 103 is provided on the underside of the slider table 102. The rotation mechanism 103 has a built-in motor, for example, as a drive source. The chuck 100 is configured to be rotatable around the θ-axis (vertical axis) via the air bearing 101 by the rotation mechanism 103. The slider table 102 is configured to be movable between the transfer position A1 and the processing position A2 by a movement mechanism 104 provided on the underside of the slider table 102 along rails 106 that are provided on a base 105 and extend in the Y-axis direction. The drive source of the movement mechanism 104 is not particularly limited, but a linear motor, for example, is used.

[0025] A laser irradiation unit 110 is provided above the chuck 100 at the processing position A2. The laser irradiation unit 110 has a laser head 111, an optical system 112, and a lens 113. The laser irradiation unit 110 can scan a laser beam. In the following description, scanning a laser beam means moving the laser beam irradiated from the lens 113 of the laser irradiation unit 110 relative to the laser absorption layer P.

[0026] The laser head 111 has a laser oscillator (not shown) that oscillates a laser beam in pulses. This laser beam is a so-called pulsed laser. 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 also have other devices besides the laser oscillator, such as an amplifier.

[0027] The optical system 112 has an optical element (not shown) that controls the intensity and position of the laser light, an attenuator (not shown) that attenuates the laser light to adjust the output, and a laser scanning unit (not shown) that scans the laser light. The laser scanning unit may be, for example, a rotary wedge scanner or a galvano scanner. The optical system 112 may also be configured to be able to control the branching of the laser light.

[0028] The lens 113 irradiates the overlapped wafer T held by the chuck 100 with laser light. The laser light emitted from the laser irradiation unit 110 passes through the first wafer W and is irradiated onto the laser absorption layer P. The lens 113 may be configured to be movable in the horizontal direction by a movement mechanism (not shown), or may be configured to be movable up and down in the vertical direction by a lifting mechanism (not shown).

[0029] Moreover, a camera 120 is provided above the chuck 100 at the delivery position A1. The camera 120 has one or more cameras selected from a macro camera, a micro camera, etc. The camera 120 may be configured to be movable in the horizontal direction by a movement mechanism (not shown), or may be configured to be movable up and down in the vertical direction by a lifting mechanism (not shown).

[0030] The camera 120 captures an image of the laminated wafer T held on the chuck 100. The camera 120 includes, for example, a coaxial lens, irradiates infrared light (IR), and receives reflected light from an object. Image data captured by the camera 120 is output to the control device 40, which will be described later.

[0031] The separation device 32 as a separation section separates the first wafer W from the second wafer S (overlapped wafer T) using the interface between the first wafer W and the laser absorption layer P as the separation portion, where the bonding strength has been reduced by the laser irradiation device 31, as a base point.

[0032] 5, the separation device 32 has an adsorption chuck 200 that adsorbs and holds the back surface Sb of the second wafer S from below, and an adsorption pad 210 that adsorbs and holds the back surface Wb of the first wafer W from above. In the separation device 32, the adsorption chuck 200 adsorbs and holds the second wafer S, and the adsorption pad 210 adsorbs and holds the first wafer W, as shown in FIG. 5, the adsorption pad 210 is raised to peel off the first wafer W from the laser absorption layer P.

[0033] The configuration of the separating device 32 is not limited to this, and any configuration may be used as long as the first wafer W can be separated from the second wafer S.

[0034] The first cleaning device 33 cleans the front surface Sa side of the second wafer S separated by peeling in the separation device 32. For example, a brush is brought into contact with the laser absorbing layer P on the front surface Sa side of the second wafer S to clean the laser absorbing layer P. Note that a pressurized cleaning liquid may be used to clean the second wafer S. The first cleaning device 33 may also be configured to clean the back surface Sb of the second wafer S as well as the front surface Sa side.

[0035] The second cleaning device 34 cleans the front surface Wa of the first wafer W separated by peeling in the separation device 32. For example, a brush is brought into contact with the front surface Wa of the first wafer W to clean the front surface Wa. A pressurized cleaning liquid may be used to clean the first wafer W. The second cleaning device 34 may also be configured to clean the back surface Wb of the first wafer W as well as the front surface Wa.

[0036] In this embodiment, as described above, the first cleaning apparatus 33 for cleaning the second wafer S and the second cleaning apparatus 34 for cleaning the first wafer W are disposed independently, but the cleaning of the first wafer W and the cleaning of the second wafer S may be performed using the same cleaning apparatus. In this case, the cleaning of the first wafer W and the second wafer S may be performed simultaneously or independently.

[0037] Furthermore, in this embodiment, the first wafer W is separated from the second wafer S using the separation device 32, but such separation may also be performed inside the laser irradiation device 31. For example, a liftable transfer pad (not shown) is provided at the transfer position A1 of the laser irradiation device 31. Then, while the chuck 100 is holding the second wafer S by suction, the transfer pad holds the first wafer W by suction, and the transfer pad is then raised, thereby separating the first wafer W from the second wafer S.

[0038] The wafer processing system 1 described above 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 overlapped wafer T in the wafer processing system 1. The program storage unit also stores a program for controlling the operation of drive systems such as the various processing devices and transport devices described above to realize wafer processing, which will be described later, in the wafer processing system 1. The program may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control device 40. The storage medium H may be temporary or non-temporary.

[0039] Next, a description will be given of wafer processing performed using the wafer processing system 1 configured as described above. In this embodiment, a first wafer W and a second wafer S are bonded together in a bonding device (not shown) external to the wafer processing system 1 to form an overlapped wafer T in advance.

[0040] First, a cassette Ct containing a plurality of overlapping wafers T is placed on the cassette placement table 11 of the carry-in / out block 10.

[0041] Next, the overlapped wafer T is removed from the cassette Ct by the wafer transfer device 22 and transferred to the laser irradiation device 31. In the laser irradiation device 31, the overlapped wafer T is transferred from the transfer arm 23 to the chuck 100 arranged at the transfer position A1, and the back surface Sb of the second wafer S is attracted and held by the chuck 100. Next, the moving mechanism 104 moves the chuck 100 to the processing position A2.

[0042] 6, a laser beam L1 (CO2 laser beam) is irradiated in pulses from the laser irradiation unit 110 onto the laser absorbing layer P, more specifically onto the interface between the laser absorbing layer P and the first wafer W. At this time, the laser beam L1 passes through the first wafer W from the rear surface Wb side of the first wafer W and is absorbed in the laser absorbing layer P. Then, this laser beam L1 reduces the bonding strength between the laser absorbing layer P and the first wafer W. Note that in the embodiments, "reduced bonding strength" refers to a state in which the bonding strength is reduced at least compared to before the irradiation of the laser beam L1, and includes peeling between the laser absorbing layer P and the first wafer W. The mechanism by which the bonding strength between the laser absorption layer P and the first wafer W decreases due to irradiation with the laser light L1 will be described in detail later.

[0043] When irradiating the laser absorbing layer P at the processing position A2 with the laser light L1, first, the overlapped wafer T (first wafer W) is imaged by the camera 120. Image data imaged by the camera 120 is output to the control device 40. The control device 40 determines the irradiation start position of the laser absorbing layer P with the laser light L1 based on the image data.

[0044] Subsequently, at the processing position A2, the laser irradiation unit 110 and the laser absorbing layer P are moved relatively to each other while irradiating the laser light L1 in pulses, thereby irradiating the entire surface of the laser absorbing layer P with the laser light L1 in a planar view, and reducing the bonding strength over the entire surface of the interface between the laser absorbing layer P and the first wafer W. Specifically, the relative rotation speed of the chuck 100 is large compared to the pulse interval of the laser light L1, and the laser light L1 is moved from the outer side to the inner side in the radial direction while rotating the overlapped wafer T, and the laser light L1 is irradiated in pulses to the annular region on the radially outer side of the laser absorbing layer P, where the irradiation regions of the laser light L1 do not overlap. At this time, the irradiation positions of the laser light L1 on the annular region on the radially outer side of the laser absorbing layer P may be arranged, for example, spirally in a planar view, or may be arranged annularly concentric with the laser absorbing layer P. Furthermore, when the relative rotation speed of the chuck 100 reaches an upper limit with respect to the pulse interval of the laser light L1, and the circular region on the radially inner side of the laser absorption layer P where the irradiation region of the laser light L1 overlaps is scanned and irradiated with the laser light L1 in the X-axis direction while the rotation of the overlapping wafer T is stopped, the chuck 100 (overlapping wafer T) is moved alternately and repeatedly in the Y-axis direction.

[0045] However, the method of irradiating the laser light L1 at the processing position A2 is not necessarily limited to this, as long as it can reduce the bonding strength over the entire surface of the interface between the laser absorbing layer P and the first wafer W. For example, when irradiating the circular region on the radially inner side of the laser absorbing layer P with the laser light L1, the overlapped wafer T may be rotated and the laser light L1 may be moved in the radial direction, so that the irradiation positions of the laser light L1 may be arranged, for example, spirally or annularly concentrically with the laser absorbing layer P in a plan view.

[0046] After the entire surface of the laser absorbing layer P is irradiated with the laser light L1 and the bonding strength between the first wafer W and the entire surface of the laser absorbing layer P is reduced, the moving mechanism 104 moves the chuck 100 (superimposed wafer T) to the delivery position A1.

[0047] Next, the laminated wafer T on the chuck 100 is transferred to the transfer arm 23 of the wafer transfer device 22 and transferred to the separation device 32. In the separation device 32, as shown in FIG. 5(a), the suction chuck 200 suction-holds the back surface Sb of the second wafer S, and the suction pad 210 suction-holds the back surface Wb of the first wafer W. Thereafter, as shown in FIG. 5(b), while the suction pad 210 suction-holds the first wafer W, the suction pad 210 is raised to peel the first wafer W from the laser absorbing layer P. At this time, since the bonding strength at the interface between the laser absorbing layer P and the first wafer W has been reduced by the irradiation of the laser light L1 as described above, the first wafer W can be separated from the laser absorbing layer P without applying a large load.

[0048] The separated first wafer W is transferred from the suction pad 210 to the transfer arm 23 of the wafer transfer device 22 and transferred to the second cleaning device 34. At this time, the first wafer W transferred from the separation device 32 may be reversed, for example, by the operation of an inverting device (not shown) or the suction pad 210, so that the front surface Wa faces upward, and then transferred to the second cleaning device 34.

[0049] In the second cleaning device 34, the front surface Wa of the first wafer W, which is the surface separated by the separation device 32, is cleaned. Note that in the second cleaning device 34, the back surface Wb may also be cleaned in addition to the front surface Wa. Alternatively, separate cleaning units may be provided for cleaning the front surface Wa and the back surface Wb, respectively. Thereafter, the first wafer W that has been cleaned by the second cleaning device 34 is transferred by the wafer transfer device 22 to the cassette Cw on the cassette mounting table 11.

[0050] On the other hand, the second wafer S held by the suction chuck 200 is transferred to the transfer arm 23 and transferred to the first cleaning device 33. In the first cleaning device 33, the front surface Sa side of the second wafer S, which is the surface separated by the separation device 32, specifically the front surface of the laser absorbing layer P, is cleaned. Note that in the first cleaning device 33, the back surface Sb of the second wafer S may also be cleaned together with the front surface of the laser absorbing layer P. Furthermore, separate cleaning units may be provided for cleaning the front surface of the laser absorbing layer P and the back surface Sb of the second wafer S, respectively. Thereafter, the second wafer S cleaned by the first cleaning device 33 is transferred to the cassette Cs of the cassette mounting table 11 by the wafer transfer device 22.

[0051] Thus, a series of wafer processing steps in the wafer processing system 1 is completed.

[0052] Next, the mechanism of the decrease in the bonding strength between the laser absorption layer P and the first wafer W caused by the irradiation of the laser light L1 at the processing position A2 of the laser irradiation device 31 will be described in detail.

[0053] As described above, at the processing position A2 of the laser irradiation device 31, the overlapped wafer T held by the chuck 100 is irradiated with the laser light L1 from the back surface Wb side of the first wafer W (step St1 in FIG. 7). The laser light L1 output from the lens 113 of the laser irradiation unit 110 passes through silicon (first wafer W) and is absorbed by the laser absorption layer P (step St2 in FIG. 7), as shown in FIG.

[0054] The laser light L1 absorbed by the laser absorbing layer P is converted into heat according to its energy distribution (step St3 in FIG. 7). In other words, the absorption of the laser light L1 increases the temperature of the laser absorbing layer P. The temperature of the laser absorbing layer P is highest in the region directly under the irradiation of the laser light L1. Most of the heat (Ht in the figure) generated in the laser absorption layer P by absorbing the laser light L1 diffuses toward the first wafer W (step St4 in FIG. 7), as shown in FIG. 8. In other words, the temperature of the interface between the laser absorption layer P and the first wafer W (silicon) rises due to the thermal diffusion from the laser absorption layer P.

[0055] When the heat generated in the laser absorption layer P diffuses toward the first wafer W side, the influence of this heat, i.e., an increase in the interface temperature between the laser absorption layer P and the first wafer W, causes the first wafer W to locally expand (plastically deform into a downward convex shape toward the laser absorption layer P side) in the area irradiated with the laser light L1 in accordance with the temperature distribution, as shown in FIG. 9 (step St5 in FIG. 7). Hereinafter, the region affected by the heat generated by irradiation with the laser light L1 may be referred to as the “irradiation region R” of the laser light L1. In other words, the first wafer W expands locally in the irradiation region R of the laser light L1.

[0056] Then, at the processing position A2, as described above, the laser light L1 is irradiated onto the entire surface of the laser absorbing layer P in plan view. In other words, as shown in Fig. 10, the laser light L1 is irradiated onto the entire surface of the laser absorbing layer P multiple times at intervals. At this time, the first wafer W expands locally every time the laser light L1 is irradiated, that is, a plurality of irradiation regions R are formed at intervals in different parts in a plan view.

[0057] Here, when the first wafer W expands, the laser absorbing layer P is pressed from above (the first wafer W side) in accordance with the expansion of the first wafer W, and as a result, a compressive stress σ1 is generated in the laser absorbing layer P at the irradiation position of the laser light L1, as shown in Fig. 10. The generated compressive stress σ1 acts in a direction that peels the first wafer W and the laser absorbing layer P (the downward direction in the figure, toward the laser absorbing layer P side), as shown in Fig. 10, to generate a peeling stress σ2. In other words, in the irradiation region R of the laser light L1, the silicon (first wafer W) expands in the region directly below the irradiation of the laser light L1 (the center of the irradiation region R), generating a compressive stress σ1, and at the same time, a peeling stress σ2, which is a stress in the peeling direction caused by the compressive stress σ1, is generated at the end Re (see FIG. 9) of the irradiation region R. This peeling stress σ2 is a tensile stress generated at the end Re of the irradiation region R.

[0058] The generated compressive stress σ1 and peeling stress σ2 are accumulated inside the laser absorption layer P. At this time, at the end Re of the irradiation region R, the peeling stresses σ2 generated in the multiple irradiation regions R act synergistically (overlappedly).

[0059] Then, when the total accumulated amount (synergistic amount) of peeling stress σ2 at the end Re of the irradiation region R exceeds the adhesion force Σ between the first wafer W and the laser absorbing layer P per unit area at the end Re (n×σ2>Σ (where n is a natural number and is the number of irradiations of the laser light L1)), peeling occurs at the interface between the first wafer W and the laser absorbing layer P at the end Re of the irradiation region R as shown in FIG. 11, and as a result, the bonding strength between the laser absorbing layer P and the first wafer W decreases (step St6 in FIG. 7). The stress σ (compressive stress σ1 and peeling stress σ2) accumulated inside the laser absorption layer P is released by the peeling of the first wafer W and the laser absorption layer P.

[0060] Then, at the processing position A2 of the laser irradiation device 31, as shown in FIG. 12, peeling occurs over the entire surface of the interface between the first wafer W and the laser absorption layer P in plan view, in other words, the peeling that occurs at the end Re of the irradiation region R is connected over the entire surface of the interface between the first wafer W and the laser absorption layer P, thereby reducing the bonding strength over the entire surface of the first wafer W and the laser absorption layer P, and thereby the first wafer W and the laser absorption layer P can be properly separated in the separation device 32 (step St7 in FIG. 7). In the overlapped wafer T after being irradiated with the laser beam L1 at the processing position A2, ideally, peeling from the laser absorbing layer P occurs over the entire surface of the first wafer W. In other words, after peeling occurs at the edge Re of the irradiation region R, the first wafer W and the laser absorbing layer P are also peeled off in the central part of the irradiation region R, including the region immediately below the irradiation, due to the peel stress σ2. However, as shown in FIG. 11 , in the central part of the irradiation region R (the region immediately below the irradiation of the laser beam L1), the first wafer W and the laser absorbing layer P may remain connected (not peeled off) even after peeling occurs at the edge Re of the irradiation region R. For this reason, in the wafer processing system 1 according to the technique of the present disclosure, in order to reliably separate the first wafer W from the overlapped wafer T (laser absorbing layer P) in the overlapped wafer T after being irradiated with the laser beam L1, it is preferable to provide a separation device 32 and to perform a process of separating the first wafer W from the overlapped wafer T in the separation device 32.

[0061] Here, when the separation of the first wafer W from the overlapped wafer T is performed in this manner using the separation device 32, if the overlapped wafer T is transported to the separation device 32 in the ideal state described above, i.e., in a state where peeling from the laser absorption layer P has occurred over the entire surface of the first wafer W, there is a risk that the first wafer W will fall off the second wafer S due to inertial forces and the like associated with this transport. Furthermore, if peeling from the laser absorbing layer P occurs over the entire surface of the first wafer W in this manner, even if there is no need to transport the polymerized wafer T after irradiation with the laser light L1 to the separation device 32, there is a risk that the first wafer W will fly off from the second wafer S due to centrifugal force or the like caused by the rotation of the chuck 100 while the laser absorbing layer P is being irradiated with the laser light L1 at the processing position A2.

[0062] In view of this, in order to prevent the first wafer W from scattering or falling during irradiation of the laser light L1 onto the laser absorption layer P and during transport of the laminated wafer T, it is preferable to control the irradiation conditions (irradiation position, output, etc.) of the laser light L1 at the processing position A2 so that at least a part of the interface between the first wafer W and the laser absorption layer P remains connected (not peeled off). As a result, the first wafer W is completely separated from the laser absorption layer P during irradiation with the laser light L1 or during transport to the separating device 32, and scattering or dropping from the second wafer S is prevented.

[0063] The reduction in the bonding strength between the laser absorbing layer P and the first wafer W at the processing position A2 of the laser irradiation device 31 is performed as described above. That is, in the laser irradiation device 31 in this embodiment, the first wafer W is expanded by heat generated by irradiation with the laser light L1, and a compressive stress σ1 is generated in the laser absorbing layer P, which generates a peeling stress σ2 at the interface between the first wafer W and the laser absorbing layer P, thereby causing peeling at the interface between the laser absorbing layer P and the first wafer W, thereby reducing the bonding strength.

[0064] In the above embodiment, as shown in FIG. 10, the laser absorbing layer P is irradiated with the laser beam L1 multiple times, and when the total accumulated amount of the resulting peeling stress σ2 exceeds the adhesion force Σ between the first wafer W and the laser absorbing layer P, peeling occurs at the end Re of the irradiated region R. However, the number of times of irradiation with the laser beam L1 until such peeling occurs is not limited to multiple times. For example, if the peel stress σ2 generated by a single irradiation (one time) of laser light L1 exceeds the adhesion force Σ, the irradiation of the single laser light L1 may cause peeling at the interface between the first wafer W and the laser absorption layer P at the end Re of the irradiation region R.

[0065] Here, if the adhesion force Σ between the first wafer and the laser absorbing layer is large, there is a risk that irradiation with the laser light L1 may not properly cause peeling at the interface between the laser absorbing layer P and the first wafer W. That is, if the adhesion force Σ between the first wafer and the laser absorbing layer is large, there is a risk that the total amount of peel stress σ2 accumulated inside the laser absorbing layer P may not exceed the adhesion force Σ per unit area between the first wafer and the laser absorbing layer.

[0066] Therefore, the present inventors have conducted extensive research and found that the adhesion force Σ, which is the threshold for delamination between the first wafer W and the laser absorbing layer P (peeling performance, which is the "ease of delamination"), is affected by the composition of the laser absorbing layer P. In other words, the inventors have found that it is possible to more appropriately and easily delaminate the laser absorbing layer P from the first wafer W in the above-described laser irradiation apparatus 31 by changing the composition of the laser absorbing layer P by controlling the type and mixture ratio of the processing gas in the process of forming the laser absorbing layer P (for example, a CVD process) performed outside the wafer processing system 1.

[0067] Specifically, for example, when the laser absorbing layer P is a SiO2 film as an oxide film, it has been found that a high nitrogen (N) component ratio in the composition of the laser absorbing layer P reduces the adhesion strength Σ between the first wafer W and the laser absorbing layer P. This is thought to be because, at the adhesion interface between the first wafer W and the laser absorbing layer P, Si-O bonds and Si-N bonds are mainly present, and among these, the ratio of Si-N bonds, which have a relatively weak bonding strength, becomes high.

[0068] Specifically, for example, when the laser absorbing layer P is a TEOS film as an oxide film, it has been found that a high carbon (C) component ratio in the composition of the laser absorbing layer P reduces the adhesion strength Σ between the first wafer W and the laser absorbing layer P. This is thought to be because, while Si-O bonds and Si-C bonds are mainly present at the adhesion interface between the first wafer W and the laser absorbing layer P, the ratio of Si-C bonds, which have a relatively weak bonding strength, increases.

[0069] Hereinafter, as an example of the oxide film constituting the laser absorption layer P, a case where an SiO2 film is formed by a CVD process will be described.

[0070] The nitrogen component ratio in the SiO2 film serving as the laser absorption layer P can be improved by increasing the silane (SiH4) ratio in the processing gas in the CVD process for forming the SiO2 film. This is because increasing the silane flow rate ratio in the processing gas reduces the flow rate ratio of nitrous oxide (NO), which contains oxygen (O) components in the processing gas for forming Si-O bonds.

[0071] It was also found that when the nitrogen component ratio in the laser absorbing layer P was large (the laser absorbing layer P was formed by increasing the flow rate ratio of silane), the adhesion force Σ between the laser absorbing layer P and the first wafer W was weaker than when the nitrogen component ratio in the laser absorbing layer P was small (the laser absorbing layer P was formed by decreasing the flow rate ratio of silane).

[0072] Specifically, the inventors formed the laser absorbing layer P when the flow rate of silane (SiH4) was set to 15 ccm (Example) and when the flow rate of silane (SiH4) was set to 5 ccm (Comparative Example). Then, for the laser absorbing layer P formed under each condition, an interface analysis between the laser absorbing layer P and the first wafer W was performed using XPS (X-ray Photoelectron Spectroscopy), and the adhesion force over the entire surface of the laser absorbing layer P and the first wafer W was measured using a nanoindenter. Other conditions for forming the laser absorbing layer P were the same for both the example and the comparative example. Specifically, the flow rate of nitrous oxide (NO) during the formation of the laser absorbing layer P was 400 ccm for both the example and the comparative example. The film thickness of the formed laser absorbing layer P was 1.0 μm for both the example and the comparative example.

[0073] First, an interface analysis was performed between the laser absorbing layer P and the first wafer W using XPS, and it was confirmed that the laser absorbing layer P formed under the conditions of the example in which the silane flow rate ratio was large during the formation of the laser absorbing layer P had a larger nitrogen component ratio than the laser absorbing layer P formed under the conditions of the comparative example in which the silane flow rate ratio was small. In other words, it was confirmed that the laser absorbing layer P formed under the conditions of the example had a higher ratio of Si-N bonds at the interface between the first wafer W and the laser absorbing layer P than the laser absorbing layer P formed under the conditions of the comparative example. This is thought to be due to the fact that, as mentioned above, increasing the flow rate of silane in the processing gas in the CVD process reduces the flow rate of nitrous oxide, which contains oxygen (O) components for forming Si-O bonds.

[0074] Next, a nanoindenter was used to measure the adhesion force between the laser absorbing layer P and the first wafer W. It was found that the laser absorbing layer P according to the example having a high nitrogen component ratio could be peeled off from the first wafer W at approximately 93 mN, but the laser absorbing layer P according to the comparative example having a low nitrogen component ratio could not be peeled off from the first wafer W. In other words, it was confirmed that the laser absorption layer P formed under the conditions of the example had a smaller adhesion force at the interface between the laser absorption layer P and the first wafer W than the laser absorption layer P formed under the conditions of the comparative example. This is thought to be due to the fact that the proportion of Si—N bonds, which have weak bonding strength, is high at the interface between the first wafer W and the laser absorption layer P, as described above.

[0075] As described above, in the wafer processing according to this embodiment, by controlling the type and mixing ratio of the processing gas used in forming the laser absorption layer P and thereby controlling the composition of the laser absorption layer P, it is possible to form a film with a weak adhesion force Σ, in other words, a film that is likely to peel off when exposed to the laser light L1 in the laser irradiation device 31. By reducing the adhesion force Σ at the interface between the laser absorption layer P and the first wafer W in this manner, it is possible to reduce the tact time for laser peeling in the laser irradiation device 31 and reduce the output of the laser light L1, thereby increasing the process margin and stabilizing the process.

[0076] A laser absorption layer P for absorbing laser light L1, a device layer Dw including a plurality of devices, and a surface film Fw used for bonding to another substrate are formed on the surface of the first wafer W. The laser absorption layer P, the device layer Dw, and the surface film Fw are sometimes collectively referred to as a "device structure" in the technology of the present disclosure. At this time, the composition of the laser absorption layer P formed on the surface of the first wafer W is controlled in accordance with the peeling performance, which is the ease with which peeling occurs between the first wafer W and the laser absorption layer P due to absorption of the laser light L1. More specifically, the flow rate ratio of the processing gases during the formation of the laser absorbing layer P is controlled in accordance with the desired peeling performance between the first wafer W and the laser absorbing layer P.

[0077] That is, the technology of the present disclosure has aspects relating to the device structure formed on the surface of the first wafer W and to the method for manufacturing the device layer.

[0078] When the laser absorbing layer P is an SiO2 film, the nitrogen component ratio of the laser absorbing layer P is controlled as the composition of the laser absorbing layer P. Furthermore, when the laser absorbing layer P is a TEOS film, the carbon component ratio of the laser absorbing layer P is controlled as the composition of the laser absorbing layer P.

[0079] In the above embodiment, an example has been described in which a device layer Dw formed on the surface Wa of a first wafer W in a wafer processing system 1 is transferred to a second wafer S, i.e., the entire surface of the first wafer W is separated from the second wafer S. However, the technology disclosed herein can also be applied to the case in which a portion of the first wafer W is separated from the second wafer S.

[0080] Specifically, the technology according to the present disclosure can also be applied to the case where only the peripheral edge portion We of the first wafer W is removed from the second wafer S as shown in FIG. 13, that is, the case where so-called edge trimming is performed. In this case, in place of the separating device 32, a peripheral edge removing device (not shown) for removing the peripheral edge We of the first wafer W is disposed in the processing block 30 of the wafer processing system 1.

[0081] 13(a) and 14, in the wafer processing system 1, first, a laser irradiation device 31 irradiates the inside of the first wafer W with laser light L2 (e.g., a YAG laser) to form a peripheral modified layer M1 along the boundary between the peripheral portion We and the central portion Wc of the first wafer W to be removed, and then irradiates the laser light L2 radially outward from the peripheral modified layer M1 to form divided modified layers M2. Note that in the subsequent drawings, for clarity of illustration, the divided modified layers M2 formed inside the first wafer W are omitted from illustration.

[0082] After the peripheral modified layer M1 and the divided modified layer M2 are formed inside the first wafer W, the same laser irradiation device 31 then irradiates laser light L1 (e.g., CO2 laser) onto the laser absorption layer P formed in at least the area corresponding to the peripheral portion We to be removed, thereby reducing the bonding strength at the interface between the first wafer W and the laser absorption layer P, as shown in Figure 13(b). The mechanism by which the bonding strength at the peripheral edge portion We decreases is the same as the mechanism by which the bonding strength decreases during the transfer of the device layer Dw described above.

[0083] The overlapped wafer T, with the bond strength reduced in the region corresponding to the peripheral edge portion We, is then transferred to a peripheral edge removal device (not shown), and as shown in Fig. 13(c), an insertion member 300 having, for example, a wedge shape is inserted toward the interface between the first wafer W and the second wafer S to remove the peripheral edge portion We of the first wafer W. More specifically, the peripheral edge portion We of the first wafer W is separated from the second wafer S using the peripheral modified layer M1 as a base point, and the peripheral edge portion We is divided into small pieces using the divided modified layer M2 as a base point.

[0084] According to the technology of the present disclosure, even when the peripheral portion We of the first wafer W is separated from the second wafer S in this manner, the peripheral portion We can be appropriately removed by reducing the bonding strength at the interface between the first wafer W and the laser absorption layer P as shown in FIG. 13(b). At this time, by controlling the composition of the oxide film constituting the laser absorbing layer P as described above, at least in the region corresponding to the peripheral edge We, the adhesion between the first wafer W and the laser absorbing layer P can be reduced, and the peripheral edge We can be removed more appropriately.

[0085] In the above embodiments, delamination occurs at the interface between the first wafer W and the laser absorbing layer P, as in the full separation of the first wafer W shown in Fig. 8 to Fig. 12 and the edge trimming process of the first wafer W shown in Fig. 13. However, as described above, a delamination promoting film may be formed on the surface Wa of the first wafer W to properly delaminate the first wafer W and the laser absorbing layer P, and in this case, delamination may occur at the interface between the delamination promoting film and the laser absorbing layer P.

[0086] 15(a), a peeling-promoting film Pe, a laser absorbing layer P, a device layer Dw, and a surface film Fw may be formed as laminated films in this order on the surface Wa of the first wafer W. The peeling-promoting film Pe is formed to facilitate peeling of the first wafer W from the second wafer S, and is made of a material that has lower adhesion to the first wafer W (silicon) than to the laser absorbing layer P and is transparent to the laser light L1, such as silicon nitride (SiN).

[0087] When separating the first wafer W from the second wafer S, first, the laser absorption layer P is irradiated with laser light L1 (step Sp1 in FIG. 16). The laser light L1 passes through the first wafer W and the peeling-promoting film Pe and is absorbed by the laser absorption layer P (step Sp2 in FIG. 16).

[0088] The laser light L1 absorbed by the laser absorbing layer P is converted into heat in accordance with its energy distribution (step Sp3 in FIG. 16), which increases the temperature of the laser absorbing layer P. Most of the heat generated in the laser absorbing layer P by absorbing the laser light L1 diffuses into the peeling-promoting film Pe on the first wafer W side (step Sp4 in FIG. 16), and this thermal diffusion increases the temperature of the interface between the laser absorbing layer P and the peeling-promoting film Pe.

[0089] When the heat generated in the laser absorbing layer P diffuses toward the first wafer W, the effect of this heat, i.e., the increase in the interface temperature between the laser absorbing layer P and the peeling-promoting film Pe, causes the peeling-promoting film Pe to expand locally in accordance with the temperature distribution, as shown in Fig. 15(b) (step Sp5 in Fig. 16). At this time, the thermal effect of the interface between the laser absorbing layer P and the peeling-promoting film Pe may affect the first wafer W, and the first wafer W may also expand locally in accordance with the temperature distribution, as shown in Fig. 15(b).

[0090] Thereafter, when the peeling-promoting film Pe (and the first wafer W) expands locally, stress caused by this expansion causes peeling at the interface between the laser absorbing layer P and the peeling-promoting film Pe, which has low adhesion, as shown in Fig. 15(c), resulting in a decrease in the bonding strength between the laser absorbing layer P and the peeling-promoting film Pe (step Sp6 in Fig. 16). Then, by continuing the peeling over the entire surface of the interface between the peeling-promoting film Pe and the laser absorbing layer P, the bonding strength over the entire surface of the peeling-promoting film Pe and the laser absorbing layer P is decreased, and as a result, the peeling-promoting film Pe and the laser absorbing layer P (the first wafer W and the second wafer S) can be properly separated in the separation device 32 (step Sp7 in Fig. 16).

[0091] In this way, by forming a peeling-promoting film Pe on the surface Wa of the first wafer W, which has lower adhesion to the first wafer W (silicon) than to the laser absorption layer P, and expanding the peeling-promoting film Pe instead of or together with the first wafer W, it is possible to properly transfer the device layer Dw formed on the surface Wa of the first wafer W and perform edge trim processing on the first wafer W.

[0092] In the example shown in FIG. 15, the peel-promoting film Pe is formed at the interface between the first wafer W and the laser absorbing layer P. However, for example, the peel-promoting film Pe may be formed at the interface between the laser absorbing layer P and the device layer Dw, and peeling may occur at the interface between the laser absorbing layer P and the peel-promoting film Pe, so that the peel-promoting film Pe remains on the second wafer S side to which the device layer Dw is transferred.

[0093] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0094] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects. [Explanation of symbols]

[0095] 1. Wafer Processing System 32 Separation device 40 Control device 100 Chuck 110 Laser irradiation unit L1 laser light P laser absorption layer R irradiation area S Second wafer T Polymerized Wafer W First wafer σ1 compressive stress σ2 peel stress

Claims

1. A substrate processing system for processing a laminated substrate formed by stacking a first substrate, an interface layer including at least a laser absorption layer, and a second substrate, comprising: a laser irradiation unit that irradiates the laser absorption layer with pulsed laser light; a control unit, the laser absorption layer is a SiO 2 film, and by controlling the nitrogen component ratio in the composition of the SiO 2 film, peeling performance, which is the ease with which peeling occurs at the interface between the first substrate or the interface layer and the laser absorption layer, is controlled; The control unit a substrate processing system that controls the irradiation of the laser light in the laser irradiation unit so that the first substrate or the interface layer is expanded by heat generated by irradiating the laser light to the laser absorption layer, and stress generated by the expansion causes the peeling to occur at the interface between the first substrate and the laser absorption layer, or at the interface between the interface layer and the laser absorption layer.

2. A substrate processing system for processing a polymerized substrate formed by stacking a first substrate, an interface layer including at least a laser absorption layer, and a second substrate, comprising: a laser irradiation unit that irradiates the laser absorption layer with pulsed laser light; a control unit, the laser absorption layer is a TEOS film, and by controlling a carbon component ratio in the composition of the TEOS film, peeling performance, which is the ease with which peeling occurs at the interface between the first substrate or the interface layer and the laser absorption layer, is controlled; The control unit a substrate processing system that controls the irradiation of the laser light in the laser irradiation unit so that the first substrate or the interface layer is expanded by heat generated by irradiating the laser light to the laser absorption layer, and stress generated by the expansion causes the peeling to occur at the interface between the first substrate and the laser absorption layer, or at the interface between the interface layer and the laser absorption layer.

3. The control unit 3. The substrate processing system according to claim 1, wherein the laser beam irradiation unit controls irradiation of the laser beam so that the stress is accumulated by irradiating the laser absorption layer with a plurality of shots of the laser beam, and the accumulated stress causes peeling between the first substrate or the interface layer and the laser absorption layer.

4. The control unit 4. The substrate processing system according to claim 3, wherein the irradiation of the laser light in the laser irradiation unit is controlled so that the peeling occurs in different regions at the interface between the first substrate or the interface layer and the laser absorption layer, and the peelings occurring in the different regions are connected to form a separation surface that serves as a starting point for separation of the first substrate or the interface layer and the laser absorption layer.

5. a separation unit that separates the first substrate from the laminated substrate; The control unit The substrate processing system according to claim 4 , wherein the separating unit is controlled so as to separate and remove at least a portion of the first substrate from the overlapped substrate, using the separation plane as a base point.

6. the interface layer comprises a release-promoting film; 3. The substrate processing system according to claim 1, wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

7. The interface layer comprises a release-promoting film, The substrate processing system according to claim 3 , wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

8. The interface layer comprises a release-promoting film, The substrate processing system according to claim 4 , wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

9. The interface layer comprises a release-promoting film, The substrate processing system according to claim 5 , wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

10. A substrate processing method for processing a laminated substrate formed by stacking a first substrate, an interface layer including at least a laser absorption layer, and a second substrate, comprising: the laser absorption layer is a SiO 2 film, and by controlling a nitrogen component ratio in the composition of the SiO 2 film, peeling performance, which is the ease with which peeling occurs at the interface between the first substrate or the interface layer and the laser absorption layer, is controlled; expanding the first substrate or the interface layer by heat generated by irradiating the laser absorption layer with laser light, and causing the peeling at the interface between the first substrate and the laser absorption layer, or at the interface between the interface layer and the laser absorption layer by stress generated by the expansion.

11. A substrate processing method for processing a polymerized substrate formed by stacking a first substrate, an interface layer including at least a laser absorption layer, and a second substrate, comprising: the laser absorption layer is a TEOS film, and by controlling a carbon component ratio which is a composition of the TEOS film, peeling performance which is the ease with which peeling occurs at the interface between the first substrate or the interface layer and the laser absorption layer is controlled; expanding the first substrate or the interface layer by heat generated by irradiating the laser absorption layer with laser light, and causing the peeling at the interface between the first substrate and the laser absorption layer, or at the interface between the interface layer and the laser absorption layer by stress generated by the expansion.

12. 12. The substrate processing method according to claim 10, wherein the stress is accumulated by irradiating the laser absorption layer with a plurality of shots of the laser light, and the accumulated stress causes the peeling between the first substrate or the interface layer and the laser absorption layer.

13. causing the delamination at different regions at an interface between the first substrate or the interface layer and the laser absorption layer; 13. The substrate processing method according to claim 12, further comprising: connecting the peelings that have occurred in the different regions to form a separation surface that serves as a starting point for separation of the first substrate or the interface layer and the laser absorption layer.

14. The substrate processing method according to claim 13 , further comprising separating and removing at least a portion of the first substrate from the laminated substrate using the separation plane as a base point.

15. the interface layer comprises a release-promoting film; The substrate processing method according to claim 10 , wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

16. The interface layer comprises a release-promoting film, The substrate processing method according to claim 12 , wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

17. The interface layer comprises a release-promoting film, The substrate processing method according to claim 13 , wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

18. The interface layer comprises a release-promoting film, The substrate processing method according to claim 14 , wherein the peeling at the interface between the interface layer and the laser absorption layer occurs at the interface between the peel-promoting film and the laser absorption layer.

19. A device structure formed on a surface of a substrate, a laminated film is formed on the surface of the substrate, The laminated film is a laser absorption layer that absorbs laser light; a device layer including a plurality of devices; a surface film to be bonded to another substrate, in this order from the surface side, A device structure in which the laser absorption layer is a SiO 2 film, and the peeling performance, which is the likelihood of peeling occurring at the interface between the substrate and the laminated film due to absorption of the laser light, is controlled by controlling the nitrogen component ratio in the composition of the SiO 2 film.

20. A device structure formed on a surface of a substrate, comprising: a laminated film is formed on the surface of the substrate, The laminated film is a laser absorption layer that absorbs laser light; a device layer including a plurality of devices; a surface film to be bonded to another substrate, in this order from the surface side, A device structure in which the laser absorption layer is a TEOS film, and the peeling performance, which is the likelihood of peeling occurring at the interface between the substrate and the laminated film due to absorption of the laser light, is controlled by controlling the carbon component ratio, which is the composition of the TEOS film.

21. The device structure according to claim 19 or 20, wherein the laminated film includes a peeling-promoting film at an interface between the surface of the substrate and the laser absorption layer.

Images