JP7815447B2 - Substrate processing system, substrate processing method, and device structure - Google Patents

Description

The present disclosure relates to a substrate processing system, a substrate processing method, and a device structure.

Patent Document 1 discloses transferring a semiconductor element from a semiconductor substrate having a separation oxide film and a semiconductor element formed on its surface to a destination substrate. The method described in Patent Document 1 includes a step of irradiating the backside of the semiconductor substrate with light to locally heat the separation oxide film, and a step of thermally expanding the separation oxide film and/or at the interface between the separation oxide film and the semiconductor substrate to cause separation, thereby transferring the semiconductor element to the destination substrate.

Japan Patent Publication No. 2007-220749

The technology disclosed herein properly separates a first substrate from a laser absorption layer in a composite substrate in which the laser absorption layer is formed at the interface between the first substrate and the second substrate.

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 absorption layer, and a second substrate, the system comprising: a laser irradiation unit that irradiates the laser absorption layer with pulsed laser light; and a control unit, wherein the control unit controls the irradiation of the laser light by the laser irradiation unit so that the heat generated by irradiating the laser absorption layer with the laser light causes the first substrate or the interface layer to expand, and the 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.

According to the present disclosure, in a polymerized 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 properly peeled off.

FIG. 2 is a side view showing a configuration example of an overlapping wafer according to an embodiment. 1 is a plan view showing an outline of the configuration of a wafer processing system according to an embodiment; 1 is a plan view showing an outline of the configuration of a laser irradiation device according to an embodiment; 1 is a side view showing an outline of the configuration of a laser irradiation device according to an embodiment. FIG. 4 is a side view illustrating an operation of the separation device according to the embodiment. FIG. 10 is an explanatory diagram showing the state of the overlapped wafer irradiated with laser light. FIG. 2 is a flow chart showing the main steps of wafer processing in the wafer processing system. 10 is an explanatory diagram showing the diffusion of heat generated in the overlapping wafer. FIG. 10A and 10B are explanatory diagrams showing expansion of the first wafer due to irradiation with laser light; FIG. 10 is an explanatory diagram showing the state of the overlapped wafer irradiated with laser light. 10A and 10B are explanatory views showing how the first wafer and the laser absorption layer are peeled off from each other. 10A and 10B are explanatory views showing how the first wafer and the laser absorption layer are peeled off from each other. FIG. 3 is an explanatory diagram showing a modified layer formed on a first substrate. FIG. 3 is an explanatory diagram showing a modified layer formed on a first substrate. 10 is an explanatory diagram showing how the peeling-promoting layer and the laser absorbing layer are peeled off. FIG. FIG. 10 is a flowchart showing main steps of wafer processing according to another embodiment.

In the semiconductor device manufacturing process, 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 carried out by irradiating a laser beam onto a laser absorption layer formed between the first wafer and the device layer, thereby peeling the first wafer away from the laser absorption layer.

The transfer of the device layer is performed, for example, using the method disclosed in Patent Document 1. That is, a peeled oxide film (laser absorption layer) formed on a semiconductor substrate is irradiated with light (laser light) to locally heat the peeled oxide film, and then a modified film is formed, for example, at the interface between the peeled oxide film and the semiconductor substrate. Peeling occurs using the modified film as a base point, and the semiconductor element is transferred to the destination substrate.

After extensive research, the inventors have come up with a new method for causing delamination at the interface between the first wafer and the laser absorption layer. Specifically, instead of irradiating the laser absorption layer with laser light to thermally expand the laser absorption layer and cause delamination, they have discovered a method in which the laser absorption layer is irradiated with laser light, and the heat generated thereby expands the first wafer, causing delamination at the interface between the first wafer and the laser absorption layer.

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. 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 below with reference to the drawings. Note that in this specification and drawings, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

In the 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.

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 of 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, SiO ₂ 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.

The laser absorbing layer P absorbs the laser light irradiated from the laser irradiation unit 110, as described below. For example, an oxide film ( _SiO2 film, TEOS film) is used for the laser absorbing layer P, but there is no particular limitation as long as it absorbs laser light. The laser absorbing layer P is formed, for example, by a chemical vapor deposition (CVD) process outside the wafer processing system 1 described below. 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.

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 surface film Fs are the same as the device layer Dw and 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 then bonded. Note that the device layer Ds and surface film Fs may not be formed on the surface Sa.

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 the 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 appropriately peeling the first wafer W and the laser absorption layer P. In this case, the above-mentioned interface layer includes the peeling-promoting film.

As shown in Figure 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 connected together. The load/unload block 10 and the processing block 30 are arranged around the transfer block 20. Specifically, the load/unload block 10 is located on the negative Y-axis side of the transfer block 20. The laser irradiation device 31 and the separation device 32, which will be described later, of the processing block 30 are located on the negative X-axis side of the transfer block 20, and the first cleaning device 33 and the second cleaning device 34, which will be described later, are located on the positive X-axis side of the transfer block 20.

The load-in/load-out block 10 loads and unloads cassettes Ct, Cw, and Cs, each capable of holding multiple overlapping wafers T, multiple first wafers W, and multiple second wafers S, to and from the outside. The load-in/load-out block 10 is provided with a cassette mounting table 11. In the illustrated example, the cassette mounting table 11 can mount multiple cassettes, for example, three cassettes Ct, Cw, and Cs, in a row in the X-axis direction. The number of cassettes Ct, Cw, and Cs mounted on the cassette mounting table 11 is not limited to this embodiment and can be determined arbitrarily.

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 be 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.

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. Note that the number and arrangement of the laser irradiation device 31, separation device 32, first cleaning device 33, and second cleaning device 34 are not limited to this.

The laser irradiation device 31 irradiates the interior of the overlapped wafer T, more specifically, the laser absorption 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 absorption layer P. In the technology disclosed herein, the interface with reduced bonding strength within this overlapped wafer T (in this embodiment, the interface between the first wafer W and the laser absorption layer P) is sometimes referred to as the "separation surface."

As shown in Figure 3, a transfer position A1 and a processing position A2 are set up inside the laser irradiation device 31. The transfer position A1 is a position where the laminated wafer T can be transferred from the transport arm 23 to the chuck 100 described below, and where the laminated wafer T (laser absorbing layer P) can be imaged by the camera 120 described below. The processing position A2 is a position where the laminated wafer T (laser absorbing layer P) can be irradiated with laser light from the laser irradiation unit 110 described below.

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 portion of the radially inner side of the back surface Sb. Examples of the chuck 100 include an electrostatic chuck (ESC) or a vacuum chuck. The chuck 100 is provided with lifting pins (not shown) for supporting and raising and lowering the overlapped wafer T from below. The lifting pins are inserted through through holes (not shown) formed through the chuck 100 and are configured to be able to be raised and lowered.

The chuck 100 is supported by the 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 incorporates, for example, a motor 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 processing position A2 by a movement mechanism 104 provided on its underside along rails 106 provided on a base 105 and extending 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.

A laser irradiation unit 110 is provided above the chuck 100 at 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 the laser light. In the following description, scanning the laser light means moving the laser light irradiated from the lens 113 of the laser irradiation unit 110 relative to the laser absorption layer P.

The laser head 111 has a laser oscillator (not shown) that oscillates a pulsed laser beam. 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 in addition to the laser oscillator, such as an amplifier.

The optical system 112 includes 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 its 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 galvanometer scanner. The optical system 112 may also be configured to control the branching of the laser light.

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 horizontally by a movement mechanism (not shown), or may be configured to be movable vertically by a lifting mechanism (not shown).

A camera 120 is provided above the chuck 100 at the transfer 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 horizontally by a movement mechanism (not shown), or may be configured to be movable vertically by a lifting mechanism (not shown).

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

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

In one example, as shown in Figure 5, the separation device 32 has a suction chuck 200 that suction-holds the back surface Sb of the second wafer S from below, and a suction pad 210 that suction-holds the back surface Wb of the first wafer W from above. In the separation device 32, as shown in Figure 5, with the suction chuck 200 suction-holding the second wafer S and the suction pad 210 suction-holding the first wafer W, the suction pad 210 is raised to peel off the first wafer W from the laser absorption layer P.

The configuration of the separation device 32 is not limited to this, and any configuration can be used as long as it can peel the first wafer W from the second wafer S.

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 absorption layer P on the front surface Sa side of the second wafer S to clean the laser absorption layer P. Note that 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.

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. Note that 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.

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 arranged 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.

In addition, 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 is used to hold the first wafer W by suction, and the transfer pad is then raised to separate the first wafer W from the second wafer S.

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 that controls the processing of the laminated wafer T in the wafer processing system 1. The program storage unit also stores a program that controls the operation of the drive systems of the various processing devices and transport devices described above to realize the wafer processing described below 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.

Next, we will explain wafer processing performed using the wafer processing system 1 configured as described above. In this embodiment, the first wafer W and the second wafer S are bonded in a bonding device (not shown) external to the wafer processing system 1 to form a laminated wafer T in advance.

First, a cassette Ct containing multiple overlapping wafers T is placed on the cassette placement table 11 of the load/unload block 10.

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 positioned at the transfer position A1, and the back surface Sb of the second wafer S is adsorbed and held by the chuck 100. Next, the moving mechanism 104 moves the chuck 100 to the processing position A2.

6 , a laser irradiating unit 110 irradiates the laser absorbing layer P, more specifically, the interface between the laser absorbing layer P and the first wafer W, with pulsed laser light L1 ( _CO2 laser light). At this time, the laser light 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. This laser light L1 reduces the bonding strength between the laser absorbing layer P and the first wafer W. Note that in the embodiment, "reduced bonding strength" refers to a state in which the bonding strength is reduced at least compared to before the irradiation of the laser light 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 is reduced by irradiation with the laser light L1 will be described in detail later.

When irradiating the laser absorption layer P with laser light L1 at processing position A2, the overlapped wafer T (first wafer W) is first imaged by camera 120. The image data captured by camera 120 is output to control device 40. Based on the image data, control device 40 determines the start position for irradiating the laser absorption layer P with laser light L1.

Next, at processing position A2, the laser irradiation unit 110 and the laser absorption layer P are moved relative to each other while irradiating the laser light L1 in pulses. This irradiates the entire surface of the laser absorption layer P in a planar view with the laser light L1, thereby reducing the bonding strength across the entire interface between the laser absorption layer P and the first wafer W. Specifically, the relative rotation speed of the chuck 100 is high compared to the pulse interval of the laser light L1, and the laser light L1 is moved from the outer radial direction to the inner radial direction while rotating the overlapping wafer T, irradiating the laser light L1 in pulses with the annular region on the radial outer side of the laser absorption layer P where the irradiation regions of the laser light L1 do not overlap. In this case, the irradiation positions of the laser light L1 on the radial outer annular region of the laser absorption layer P may be arranged, for example, spirally in a planar view or concentrically in a circular pattern with the laser absorption 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 subjected to scanning irradiation of the laser light L1 in the X-axis direction and movement of the chuck 100 (the overlapping wafer T) in the Y-axis direction, with the rotation of the overlapping wafer T stopped.

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 interface between the laser absorbing layer P and the first wafer W. For example, when irradiating the circular region radially inward of the laser absorbing layer P with the laser light L1, the overlapping wafer T may be rotated and the laser light L1 may be moved radially, so that the irradiation positions of the laser light L1 are arranged, for example, spirally or annularly concentrically with the laser absorbing layer P in a planar view.

After the laser light L1 is irradiated onto the entire surface of the laser absorption layer P and the bonding strength between the first wafer W and the entire surface of the laser absorption layer P is reduced, the chuck 100 (superimposed wafer T) is then moved to the transfer position A1 by the moving mechanism 104.

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. Then, as shown in FIG. 5(b), while the suction pad 210 is suction-holding the first wafer W, the suction pad 210 is raised to peel the first wafer W from the laser absorption layer P. At this time, because the bonding strength at the interface between the laser absorption layer P and the first wafer W is reduced by the irradiation of the laser light L1 as described above, the first wafer W can be separated from the laser absorption layer P without applying a large load.

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 inverted, for example, by the operation of an inversion 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.

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. The second cleaning device 34 may also clean the back surface Wb as well as the front surface Wa. Separate cleaning units may also be provided for cleaning the front surface Wa and back surface Wb, respectively. The first wafer W that has been cleaned by the second cleaning device 34 is then transported by the wafer transport device 22 to the cassette Cw on the cassette mounting table 11.

Meanwhile, the second wafer S held by the suction chuck 200 is transferred to the transfer arm 23 and transported to the first cleaning device 33. In the first cleaning device 33, the front surface Sa of the second wafer S, which is the surface separated by the separation device 32, specifically the surface of the laser absorption layer P, is cleaned. Note that the first cleaning device 33 may also clean the back surface Sb of the second wafer S along with the front surface of the laser absorption layer P. Separate cleaning units may also be provided for cleaning the front surface of the laser absorption layer P and the back surface Sb of the second wafer S. The second wafer S, which has been cleaned by the first cleaning device 33, is then transported by the wafer transfer device 22 to the cassette Cs on the cassette mounting table 11.

This completes the series of wafer processing steps in wafer processing system 1.

Next, we will explain in detail the mechanism behind the reduction in bonding strength between the laser absorption layer P and the first wafer W caused by irradiation of laser light L1 at the processing position A2 of the above-mentioned laser irradiation device 31.

As described above, at processing position A2 of the laser irradiation device 31, the overlapped wafer T held on the chuck 100 is irradiated with laser light L1 from the back surface Wb side of the first wafer W (step St1 in FIG. 7). As shown in FIG. 6, the laser light L1 output from the lens 113 of the laser irradiation unit 110 passes through the silicon (first wafer W) and is absorbed by the laser absorption layer P (step St2 in FIG. 7).

The laser light L1 absorbed by the laser absorbing layer P is converted into heat in accordance with 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.
8, most of the heat (Ht in the figure) generated in the laser absorbing layer P by absorbing the laser light L1 diffuses toward the first wafer W (step St4 in FIG. 7). In other words, the heat diffusion from the laser absorbing layer P causes the temperature of the interface between the laser absorbing layer P and the first wafer W (silicon) to rise.

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 temperature at the interface 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 portion 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.

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 portions in a plan view.

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 drawing, 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.

The generated compressive stress σ1 and peel stress σ2 are accumulated inside the laser absorption layer P. At this time, at the end Re of the irradiated region R, the peel stress σ2 generated in multiple irradiated regions R acts synergistically (overlappingly).

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 absorption 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 absorption 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 absorption 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.

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, by connecting the peeling that occurs at the end portion Re of the irradiation region R over the entire surface of the interface between the first wafer W and the laser absorption layer P, the bonding strength over the entire surface of the first wafer W and the laser absorption layer P is reduced, and this allows the first wafer W and the laser absorption layer P to 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 end 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 end 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 step of separating the first wafer W from the overlapped wafer T in the separation device 32.

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 absorption 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 to the separation device 32 after irradiation with the laser light L1, there is a risk that the first wafer W will fly off from the second wafer S due to centrifugal force, etc., associated with the rotation of the chuck 100 while the laser light L1 is being irradiated onto the laser absorption layer P at the processing position A2.

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 portion of the interface between the first wafer W and the laser absorption layer P remains connected (not peeled off).
This allows the first wafer W to be completely separated from the laser absorption layer P during irradiation with the laser light L1 or during transport to the separation device 32, and prevents the first wafer W from scattering or falling off the second wafer S.

The bond strength between the laser absorption layer P and the first wafer W at processing position A2 of the laser irradiation device 31 is reduced as described above. That is, in this embodiment, the laser irradiation device 31 expands the first wafer W due to heat generated by irradiation with laser light L1, generating compressive stress σ1 in the laser absorption layer P, which generates peel stress σ2 at the interface between the first wafer W and the laser absorption layer P. This causes peeling at the interface between the laser absorption layer P and the first wafer W, thereby reducing the bond strength.

In the above embodiment, as shown in FIG. 10 , the laser absorbing layer P is irradiated with the laser light 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 light L1 until such peeling occurs is not limited to multiple times.
For example, if the peeling 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.

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

Therefore, the inventors conducted extensive research and discovered that the adhesion force Σ, which is the threshold for delamination between the first wafer W and the laser absorbing layer P (delamination performance, which is the "ease of delamination"). In other words, they discovered that by changing the composition of the laser absorbing layer P by controlling the type and mixture ratio of the process gas in a laser absorbing layer P formation process (e.g., a CVD process) performed outside the wafer processing system 1, it may be possible to more appropriately and easily delaminate the laser absorbing layer P from the first wafer W in the laser irradiation device 31 described above.

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 low bonding strength, becomes high.

More specifically, for example, when the laser absorption layer P is a TEOS film serving as an oxide film, it has been found that the adhesion strength Σ between the first wafer W and the laser absorption layer P decreases when the carbon (C) component ratio in the composition of the laser absorption layer P is high. This is thought to be due to the fact that, at the adhesion interface between the first wafer W and the laser absorption layer P, Si-O bonds and Si-C bonds are primarily present, and of these, the proportion of Si-C bonds, which have a relatively low bonding strength, increases.

Hereinafter, as an example of the oxide film constituting the laser absorption layer P, a case where a SiO ₂ film is formed by a CVD process will be described.

The nitrogen component ratio in the SiO ₂ film serving as the laser absorption layer P can be improved by increasing the silane (SiH ₄ ) ratio in the processing gas in the CVD process for forming the SiO ₂ film, for example. This is because increasing the silane flow rate ratio in the processing gas reduces the flow rate ratio of nitrous oxide (N ₂ O), which contains oxygen (O) components in the processing gas for forming Si—O bonds.

It was also found that when the nitrogen component ratio in the laser absorption layer P was high (laser absorption layer P was formed by increasing the silane flow rate ratio), the adhesion force Σ between the laser absorption layer P and the first wafer W was weaker than when the nitrogen component ratio in the laser absorption layer P was low (laser absorption layer P was formed by decreasing the silane flow rate ratio).

Specifically, the inventors formed the laser absorbing layer P in two cases: when the flow rate of silane (SiH ₄ ) during the formation of the laser absorbing layer P was 15 ccm (Example), and when the flow rate of silane (SiH ₄ ) during the formation of the laser absorbing layer P was 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 ( _N2O ) 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.

First, an interface analysis was carried out 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 absorption 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 absorption layer P than the laser absorption layer P formed under the conditions of the comparative example.
This is thought to be because, as described 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.

Next, a nanoindenter was used to measure the adhesion force between the laser absorption layer P and the first wafer W. It was found that the laser absorption 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, whereas the laser absorption 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.

In this way, 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.

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. In the technology of the present disclosure, the laser absorption layer P, the device layer Dw, and the surface film Fw are collectively sometimes referred to as a "device structure."
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.

In other words, the technology disclosed herein 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.

When the laser absorbing layer P is an SiO ₂ 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.

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 a first wafer W is separated from a second wafer S.

Specifically, the technology according to the present disclosure can also be applied to the case where only the peripheral 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 processing is performed.
In this case, 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 in place of the separating device 32 .

13(a) and 14, in this wafer processing system 1, first, laser irradiation device 31 irradiates the interior 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 edge portion We and the central portion We of the first wafer W to be removed, and laser light L2 is irradiated radially outward from the peripheral modified layer M1 to form divided modified layers M2. Note that in subsequent drawings, for clarity, the divided modified layers M2 formed inside the first wafer W are omitted from illustration.

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 is then used to irradiate 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.

The overlapped wafer T, with its bond strength reduced in the area corresponding to the peripheral edge We, is then transferred to a peripheral edge removal device (not shown), where, as shown in FIG. 13(c), a wedge-shaped insertion member 300 is inserted toward the interface between the first wafer W and the second wafer S to remove the peripheral edge We of the first wafer W. More specifically, the peripheral edge 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 We is broken into small pieces using the dividing modified layer M2 as a base point.

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 absorption 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 absorption layer P can be reduced, and the peripheral edge We can be removed more appropriately.

In the above embodiments, delamination occurs at the interface between the first wafer W and the laser absorption layer P, as in the full separation of the first wafer W shown in Figures 8 to 12 and the edge trimming process of the first wafer W shown in Figure 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 from the laser absorption layer P, and in this case, delamination may occur at the interface between the delamination-promoting film and the laser absorption layer P.

Specifically, as shown in FIG. 15(a), a laminated film consisting of a peel-promoting film Pe, a laser absorption layer P, a device layer Dw, and a surface film Fw may be formed on the surface Wa of the first wafer W in this order. The peel-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 absorption layer P and is transparent to the laser light L1, such as silicon nitride (SiN).

When separating the first wafer W from the second wafer S, first, laser light L1 is irradiated onto the laser absorption layer P (step Sp1 in Figure 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 Figure 16).

The laser light L1 absorbed by the laser absorption layer P is converted into heat according to its energy distribution (step Sp3 in FIG. 16), causing the temperature of the laser absorption layer P to rise. Most of the heat generated in the laser absorption 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 causes the temperature at the interface between the laser absorption layer P and the peeling-promoting film Pe to rise.

When the heat generated in the laser absorption layer P diffuses toward the first wafer W, the effect of this heat, i.e., the increase in the interface temperature between the laser absorption 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 absorption 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).

Subsequently, when the peel-promoting film Pe (and first wafer W) expands locally, the stress generated by this expansion causes peeling at the interface between the laser absorption layer P and the peel-promoting film Pe, which has low adhesion, as shown in FIG. 15(c), resulting in a decrease in the bond strength between the laser absorption layer P and the peel-promoting film Pe (step Sp6 in FIG. 16). By continuing the peeling across the entire interface between the peel-promoting film Pe and the laser absorption layer P, the bond strength between the peel-promoting film Pe and the laser absorption layer P is reduced across the entire surface, allowing the separation device 32 to properly separate the peel-promoting film Pe and the laser absorption layer P (first wafer W and second wafer S) (step Sp7 in FIG. 16).

In this way, by forming a peel-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 peel-promoting film Pe in place 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.

In the example shown in Figure 15, the peel-promoting film Pe is formed at the interface between the first wafer W and the laser absorption layer P, but it is also possible to form the peel-promoting film Pe at the interface between the laser absorption layer P and the device layer Dw, and cause peeling at the interface between the laser absorption 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.

The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the spirit and scope of the appended claims. For example, the components of the above-described embodiments may be combined in any manner. Such combinations will naturally produce the functions and effects of each of the components involved in the combination, as well as other functions and effects that will be apparent to those skilled in the art from the description herein.

Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology disclosed herein may achieve other effects in addition to or in place of the above-described effects that would be apparent to those skilled in the art from the description herein.

REFERENCE SIGNS LIST 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 overlapped wafer W first wafer σ1 compressive stress σ2 peeling stress

Claims (21)

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 SiO2 film, and by controlling the nitrogen component ratio in the composition of the SiO2 _{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. 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 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. 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. 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. 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. 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. 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. 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. 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. 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 SiO2 film, and by controlling a nitrogen component ratio in the composition of the SiO2 _{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. 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 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. 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. 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. 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. 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. 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. 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. 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. 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 SiO2 _film , and 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 SiO2 film. 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 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. 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.