Processing method and processing system

Abstract

Provided is a method for processing a stacked substrate in which a first substrate and a second substrate are joined. The method includes: obtaining the amount of eccentricity between the first substrate and the second substrate; forming a peripheral modified layer to be used as the starting point of peeling of a peripheral section of the first substrate by radiating an internal laser beam along the boundary between the peripheral section and a central section of the first substrate; and removing the peripheral section, starting from the peripheral modified layer. When the peripheral modified layer is formed, the radiation position of the internal laser beam is determined on the basis of the amount of eccentricity.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a substrate processing system having a reforming layer forming device that forms a reforming layer inside a first substrate along the boundary between the peripheral portion and the central portion of the first substrate to be removed in a polymerized substrate in which a first substrate and a second substrate are joined, and a peripheral removing device that removes the peripheral portion of the first substrate with the reforming layer as a base point.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology according to the present disclosure appropriately removes the peripheral portion of the first substrate in a polymerized substrate in which a first substrate and a second substrate are joined.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a method for processing a polymerized substrate in which a first substrate and a second substrate are joined, including obtaining an amount of eccentricity between the first substrate and the second substrate, irradiating internal laser light along the boundary between the peripheral portion of the first substrate and the central portion of the first substrate to form a peripheral reforming layer serving as a base point for peeling of the peripheral portion, and removing the peripheral portion with the peripheral reforming layer as a base point, and when forming the peripheral reforming layer, determining an irradiation position of the internal laser light based on the amount of eccentricity.

Effects of the Invention

[0006] According to this disclosure, in a polymerized substrate in which a first substrate and a second substrate are joined, the peripheral edge of the first substrate can be appropriately removed. [Brief explanation of the drawing]

[0007] [Figure 1] This is a side view showing an example of the configuration of a polymerized wafer to be processed. [Figure 2] This is a plan view showing a schematic configuration of the wafer processing system according to this embodiment. [Figure 3] This is a cross-sectional view showing the bonding strength reduction region, peripheral modified layer, and segmented modified layer formed on the polymerized wafer. [Figure 4] This is a side view showing a schematic configuration of the interface modification device and the internal modification device. [Figure 5] This is an explanatory diagram showing the operation of the displacement detection unit. [Figure 6] This is an explanatory diagram showing other possible arrangements of the displacement detection unit. [Figure 7] This is a side view showing other configuration examples of the interface modification device and the internal modification device. [Figure 8] This is a flowchart showing the main steps in wafer processing in a wafer processing system. [Figure 9] This is an explanatory diagram showing an example of the measurement results obtained by the displacement detection unit. [Figure 10] This is an explanatory diagram showing the main processes of wafer processing in a wafer processing system. [Figure 11] This is a plan view showing other configuration examples of the interface modification device and the internal modification device. [Figure 12] This is an explanatory diagram showing other examples of the formation of a region with reduced bonding strength. [Figure 13] This is an explanatory diagram showing other examples of peripheral modified layer formation. [Figure 14] This is an explanatory diagram showing other examples of peripheral modified layer formation. [Figure 15] This is an explanatory diagram showing other wafer processing steps in a wafer processing system. [Modes for carrying out the invention]

[0008] In the manufacturing process of semiconductor devices, edge trimming is sometimes performed on a polymer substrate formed by joining a first substrate (a silicon substrate such as a semiconductor) on which multiple electronic circuits and other devices are formed on its surface with a second substrate. In this edge trimming, for example, the peripheral edge of the first substrate to be removed is used as a reference, and a predetermined trim width is used to remove the peripheral edge.

[0009] Edge trimming of the first substrate is performed, for example, using a substrate processing system disclosed in Patent Document 1. Specifically, a modified layer is formed by irradiating the interior of the first substrate with a first laser beam from the first substrate side, and the peripheral portion is removed from the first substrate using the modified layer as a starting point. Furthermore, according to the substrate processing system described in Patent Document 1, a modified surface is formed by irradiating the interface where the first substrate and the second substrate are joined with a second laser beam, thereby reducing the bonding force between the first substrate and the second substrate at the peripheral portion and ensuring proper removal of the peripheral portion.

[0010] Incidentally, in the polymer substrate to be processed, there may be misalignment between the first and second substrates due to, for example, the bonding accuracy in the bonding apparatus. In this case, if there is a requirement to uniformly process the trim width of the first substrate using the edge of the second substrate as a reference, it becomes difficult to meet this requirement.

[0011] Furthermore, a first laser beam for forming the modified layer may be irradiated from the first substrate side, and a second laser beam for forming the modified surface may be irradiated from the second substrate side. In other words, a process in which laser beam irradiation from the first substrate side and laser beam irradiation from the second substrate side are mixed may be executed in the system.

[0012] However, when laser light irradiation from both the upper and lower surfaces of the polymer substrate is mixed as described above, if the positional deviation between the first substrate and the second substrate described above occurs, it is difficult to make the irradiation positions of the first laser light from the first substrate side and the second laser light from the second substrate side coincide, and there is a risk that the peripheral portion of the first substrate cannot be appropriately removed.

[0013] The technology according to the present disclosure has been made in view of the above circumstances, and in a polymer substrate in which a first substrate and a second substrate are joined, the peripheral portion of the first substrate is appropriately removed. Hereinafter, a wafer processing system as a processing system according to the present embodiment and a wafer processing method as a processing method will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0014] In the wafer processing system 1 according to the present embodiment described later, as shown in FIG. 1, processing is performed on a polymer wafer T in which a first wafer W and a second wafer S are joined. A wafer is an example of a substrate. Hereinafter, in the first wafer W, the surface on the side joined to the second wafer S is referred to as the front surface Wa, and the surface on the side opposite to the front surface Wa is referred to as the back surface Wb. Similarly, in the second wafer S, the surface on the side joined to the first wafer W is referred to as the front surface Sa, and the surface on the side opposite to the front surface Sa is referred to as the back surface Sb.

[0015] The first wafer W is a semiconductor wafer such as a silicon substrate, and a device layer Dw including a plurality of devices is formed on the surface Wa side. Further, a bonding film Fw is formed on the device layer Dw, and it is bonded to the second wafer S through the bonding film Fw. As the bonding film Fw, for example, an oxide film (THOX film, SiO2 film, TEOS film), SiC film, SiCN film, or an adhesive is used. The peripheral portion We of the first wafer W is chamfered, and the cross-section of the peripheral portion We becomes thinner toward its tip. The peripheral portion We is a portion to be removed in the edge trimming described later, and is, for example, in the range of 0.5 mm to 3 mm in the radial direction from the outer end portion of the first wafer W. In the following description, the region radially inside the peripheral portion We to be removed in the first wafer W may be referred to as the central portion Wc.

[0016] The second wafer S has, for example, the same configuration as the first wafer W, a device layer Ds and a bonding film Fs are formed on the surface Sa, and the peripheral portion is chamfered. The second wafer S does not necessarily have to be a device wafer on which the device layer Ds is formed, and may be, for example, a support wafer that supports the first wafer W. In such a case, the second wafer S functions as a protective material that protects the device layer Dw of the first wafer W.

[0017] As shown in FIG. 2, the wafer processing system 1 has a configuration in which the loading / unloading station 2 and the processing station 3 are integrally connected. In the loading / unloading station 2, for example, a cassette C capable of accommodating a plurality of polymer wafers T is loaded / unloaded to / from the outside. The processing station 3 includes various processing devices that perform desired processing on the polymer wafer T.

[0018] The loading / unloading station 2 is equipped with a cassette mounting table 10 on which a cassette C capable of accommodating multiple polymerized wafers T is placed. Adjacent to the cassette mounting table 10, on the positive X-axis side, is a wafer transport device 20. The wafer transport device 20 moves along a transport path 21 extending in the Y-axis direction and is configured to transport polymerized wafers T between the cassette C on the cassette mounting table 10 and the transition device 30 described later.

[0019] At the loading / unloading station 2, a transition device 30 and an inversion device 31 are provided adjacent to the wafer transport device 20 on the positive X-axis side of the wafer transport device 20. The transition device 30 and the inversion device 31 are arranged in a stacked configuration.

[0020] The transition device 30 temporarily holds the polymerized wafer T being transferred between the loading / unloading station 2 and the processing station 3. The inversion device 31 inverts the front and back surfaces of the polymerized wafer T to be processed at the processing station 3. The configuration of the transition device 30 and the inversion device 31 is arbitrary.

[0021] Processing station 3 is equipped with a wafer transport device 40, an interface modification device 50, an internal modification device 60, a peripheral removal device 70, and a cleaning device 80.

[0022] The wafer transfer device 40 is located on the positive X-axis side of the transition device 30 and the inversion device 31. The wafer transfer device 40 is configured to move freely along a transfer path 41 extending in the X-axis direction and is capable of transporting polymerized wafers T to the transition device 30, the inversion device 31, the interface modification device 50, the internal modification device 60, the peripheral removal device 70, and the cleaning device 80.

[0023] In the interface modification apparatus 50, a first laser beam (interface laser beam, for example, a CO2 laser) is irradiated onto the interface between the first wafer W and the second wafer S, forming a bonding force reduction region Ae (see Figure 3) in the peripheral area We to be removed, where the bonding force between the first wafer W and the second wafer S is reduced. The interface modification apparatus 50 also detects the amount of horizontal displacement between the first wafer W and the second wafer S, or in other words, the amount of eccentricity between the first wafer W and the second wafer S, in the polymerized wafer T to be processed.

[0024] As shown in Figure 4, the interface modification apparatus 50 has a chuck 100 as a substrate holder that holds the polymerized wafer T on its upper surface. The chuck 100 is supported by a slider table 102 via an air bearing 101. A rotating mechanism 103 is provided on the lower side of the slider table 102. The rotating mechanism 103 incorporates, for example, a motor as a drive source. The chuck 100 is configured to rotate freely around a vertical axis via the air bearing 101 through the rotating mechanism 103. The slider table 102 is configured to move freely along a rail 106 that extends in the Y-axis direction on a base 105 via a moving mechanism 104 provided on its lower side. The drive source for the moving mechanism 104 is not particularly limited, but for example, a linear motor can be used.

[0025] A laser irradiation unit 110 is provided above the chuck 100. The laser irradiation unit 110 includes a laser head 111, an optical system 112, and a lens 113.

[0026] The laser head 111 has a laser oscillator (not shown) that emits interface laser light in a pulsed manner. This interface laser light is a so-called pulsed laser. As described above, the interface laser light is, for example, CO2 laser light, and the wavelength of the CO2 laser light is, for example, 8.9 μm to 11 μm. The laser head 111 may also have other equipment besides the laser oscillator, such as an amplifier.

[0027] The optical system 112 may include an optical element (not shown) that controls the intensity and position of the interface laser beam, and an attenuator (not shown) that attenuates the interface laser beam to adjust the output. The optical system 112 may also be configured to control the number and shape of branches of the interface laser beam.

[0028] The lens 113 irradiates the interior of the polymerized wafer T held by the chuck 100, more specifically the interface between the first wafer W and the second wafer S, with interface laser light. This modifies the portion of the polymerized wafer T irradiated with interface laser light, forming a bonding force reduction region Ae in which the bonding force between the first wafer W and the second wafer S is reduced. In the technology of this disclosure, "the interface between the first wafer W and the second wafer S" includes the interfaces of the first wafer W, the device layers Dw and Ds, the bonding films Fw and Fs, and the second wafer S, as well as the interiors of each. In other words, as long as the bonding force between the first wafer W and the second wafer S can be reduced, the formation location of the bonding force reduction region Ae is not particularly limited.

[0029] A displacement detection unit 120 is provided on the side of the chuck 100. The displacement detection unit 120 includes a length measuring sensor 121 and a calculation unit 122.

[0030] The length measuring sensor 121 measures the distance between the length measuring sensor 121 and the outer edge of the polymerized wafer T at multiple points in the circumferential direction of the polymerized wafer T, preferably around the entire circumference of the polymerized wafer T, while rotating the chuck 100. The type of length measuring sensor 121 is not particularly limited, and for example, an interferometer or a displacement meter can be used. The measurement width H (field of view of the measurement sensor 121) of the outer edge of the superimposed wafer T by the measurement sensor 121 is determined to be a width that can detect at least the distance Lw from the measurement sensor 121 to the outer edge of the first wafer W, and the distance Ls from the measurement sensor 121 to the outer edge of the second wafer S, as shown in Figure 5. The "outer edges of the first wafer W and the second wafer S" to be measured are preferably the apex portions, which are the vertices of the chamfered portions applied to the periphery of the first wafer W and the second wafer S, respectively.

[0031] The calculation unit 122 calculates the amount of horizontal displacement between the first wafer W and the second wafer S from the difference between the distance Lw and distance Ls measured by the length measuring sensor 121, and further calculates the amount of eccentricity between the first wafer W and the second wafer S from the amount of displacement at multiple points in the circumferential direction of the superimposed wafer T.

[0032] The calculation unit 122 may be provided independently in the interface modification apparatus 50 as shown in Figure 4, or it may be included in the control device 90 described later.

[0033] In this embodiment, the distance from the length measuring sensor 121 of the displacement detection unit 120 to the rotation center of the chuck 100, and the distance from the length measuring sensor 121 to the lens 113 of the laser irradiation unit 110 are pre-stored in the control device 90, for example.

[0034] The internal modification apparatus 60 irradiates the interior of the first wafer W with a second laser beam (internal laser beam, such as a fiber laser or YAG laser) to form a peripheral modification layer M1 (see Figure 3) which serves as a starting point for peeling off the peripheral We, and a segmented modification layer M2 (see Figure 3) which serves as a starting point for fragmenting the peripheral We.

[0035] The configuration of the internal modification apparatus 60 is not particularly limited. In one example, the internal modification apparatus 60 may have the same configuration as the interface modification apparatus 50. That is, as shown in Figure 4, the internal modification apparatus 60 may include a chuck 200 for holding the polymerized wafer T on its upper surface, a laser irradiation unit 210 for irradiating the first wafer W held by the chuck 200 with internal laser light, and a displacement detection unit 220 for detecting the amount of horizontal displacement between the first wafer W and the second wafer S.

[0036] The chuck 200, which serves as the substrate holder, can be configured to be rotatable around a vertical axis by a rotation mechanism 203 and to be movable along the horizontal direction by a movement mechanism 204.

[0037] The laser irradiation unit 210 may include a laser head 211, an optical system 212, and a lens 213. The laser head 211 may have a laser oscillator (not shown) that emits internal laser light in a pulsed manner. This internal laser light is a so-called pulsed laser. As described above, the internal laser light is, for example, fiber laser light or YAG laser light.

[0038] The displacement detection unit 220 includes a length measuring sensor 221 for measuring the distance to the outer edge of the polymerized wafer T, and a calculation unit 222 for calculating the horizontal displacement and eccentricity of the first wafer W and the second wafer S based on the measurement results from the length measuring sensor 221.

[0039] In the example shown in Figure 4, both the interface modification apparatus 50 and the internal modification apparatus 60 are equipped with displacement detection units 120 and 220 for detecting the amount of displacement between the first wafer W and the second wafer S. However, if the order of processing the polymerized wafer T in the wafer processing system 1, that is, the formation of the bonding force reduction region Ae in the interface modification apparatus 50 and the formation of the peripheral modification layer M1 in the internal modification apparatus 60, is predetermined, then either of these displacement detection units 120 or 220 may be omitted.

[0040] The edge removal device 70 removes the peripheral portion We of the first wafer W, i.e., edge trims, using the peripheral modified layer M1 formed in the internal modification device 60 as a starting point. The edge trimming method can be arbitrarily selected. For example, the edge removal device 70 may insert, for example, a wedge-shaped blade into the interface between the first wafer W and the second wafer S. Alternatively, for example, an impact may be applied to the peripheral portion We by spraying an air blower or a water jet towards the peripheral portion We.

[0041] The cleaning apparatus 80 cleans the first wafer W and the second wafer S after edge trimming by the edge removal apparatus 70, and removes particles from these wafers. The cleaning method can be arbitrarily selected.

[0042] The cleaning device 80 may also remove the surface film remaining on the surface Sa of the second wafer S after edge trimming by the peripheral removal device 70. The surface film to be removed includes, as an example, bonding films Fw, Fs and device layers Dw, Ds.

[0043] The wafer processing system 1 described above is provided with a control device 90. The control device 90 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the processing of the polymerized wafer T in the wafer processing system 1. The program storage unit also stores a program that controls the operation of the various processing devices and transport devices and other drive systems to realize the wafer processing described later in the wafer processing system 1. The above program may have been recorded on a storage medium readable by the computer and installed from that storage medium to the control device 90. The above storage medium may be temporary or permanent.

[0044] Although various exemplary embodiments have been described above, the invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and modifications may be made. Furthermore, it is possible to combine elements from different embodiments to form other embodiments.

[0045] For example, in the above embodiment, as shown in Figure 4, the length measuring sensor 121 of the displacement detection unit 120 was installed on the negative X-axis side of the chuck 100, in other words, in a position opposite the chuck 100 in a direction perpendicular to the direction of movement of the chuck 100 (X-axis direction). However, the arrangement of the length measuring sensor 121 is not limited to this. Specifically, as shown in Figure 6, the length measuring sensor 121 of the displacement detection unit 120 may be installed on the negative Y-axis side of the chuck 100, in other words, in a position opposite the chuck 100 on the axis of movement of the chuck 100 (direction of movement).

[0046] As described later, after measuring the distance Lw and distance Ls (the amount of horizontal displacement between the first wafer W and the second wafer S) using the length measuring sensor 121, the Y-axis component of the eccentricity is corrected based on the calculated eccentricity. To confirm whether this Y-axis component correction has been performed appropriately, by installing the length measuring sensor 121 on the negative Y-axis side of the chuck 100, the chuck 100 moves in the Y-axis direction, and the distance between the wafer and the length measuring sensor 121 becomes constant, allowing for a more accurate confirmation of whether the Y-axis component correction has been performed.

[0047] Furthermore, in the above embodiment, for example, the description was given using the case where the displacement detection units 120 and 220 in the interface modification apparatus 50 and the internal modification apparatus 60 include length measuring sensors 121 and 221 such as interferometers and displacement meters that detect the distance to the outer edge of the polymerized wafer T. However, the configuration of the displacement detection unit is not limited to this, as long as the displacement amount of the first wafer W and the second wafer S can be detected.

[0048] Specifically, as shown in Figure 7, for example, the displacement detection unit 320 may have a pair of cameras 321 and 322 that image the outer edge of the polymerized wafer T held by the chuck 300 as a substrate holder from above and below. It is desirable that the pair of cameras 321 and 322 are provided coaxially in the vertical direction, or that the amount of displacement in the horizontal direction is known. In this case, the outer edge of the first wafer W and the outer edge of the second wafer S are imaged from above and below using the cameras 321 and 322, respectively, and the displacement amount of the first wafer W and the second wafer S can be calculated based on the positional displacement amount of the outer edge of the first wafer W and the outer edge of the second wafer S obtained from the imaged images and the positional relationship of the cameras 321 and 322 acquired in advance.

[0049] In this case, cameras 321 and 322 are connected to the Chuck, similar to the length measuring sensor 121 shown in Figure 6. 300 It is desirable to position the chuck 300 vertically on the negative Y-axis side. In this way, the pair of cameras 321 and 322 are chucked 300 The negative Y-axis side (chuck) 300By positioning them on the movement axis, the imaging position of the polymerized wafer T by cameras 321 and 322 becomes constant, allowing for a more accurate calculation of the displacement between the first wafer W and the second wafer S.

[0050] In this case, it is desirable that the chuck 300 holding the polymerized wafer T has a configuration that allows for appropriate imaging of the outer edge of the second wafer S from below. Specifically, as shown in Figure 7, for example, it is desirable that the chuck 300 has a smaller diameter than the polymerized wafer T. That is, it is desirable that the outer edge of the second wafer S to be detected protrudes radially outward from the outer edge of the chuck 300. Alternatively, the chuck 300 may be made of a transparent material such as glass, and configured to allow imaging of the outer edge of the second wafer S through the chuck 300.

[0051] Next, a wafer processing procedure performed using the wafer processing system 1 configured as described above will be explained. In this embodiment, a first wafer W and a second wafer S are bonded together to form a polymerized wafer T in advance.

[0052] First, a cassette C containing multiple polymerized wafers T is placed on the cassette platform 10 of the loading / unloading station 2. Next, the polymerized wafers T are removed from the cassette C by the wafer transport device 20 and transported to the interface modification device 50 via the transition device 30 and the wafer transport device 40. At this time, if the polymerized wafer T is contained in cassette C with the second wafer S facing upwards, the polymerized wafer T is directly transported from cassette C to the interface modification apparatus 50. On the other hand, if the polymerized wafer T is contained in cassette C with the first wafer W facing upwards, the front and back surfaces of the polymerized wafer T are inverted via the inversion device 31 before being transported to the interface modification apparatus 50. In other words, the chuck 100 of the interface modification apparatus 50 holds the entire back surface Wb of the first wafer W by adsorption when the second wafer S is positioned on top and the first wafer W is positioned on the bottom.

[0053] In the interface modification apparatus 50, first, the displacement amount detection unit 120 is used to detect the horizontal displacement amount (eccentricity of the first wafer W and the second wafer S) of the polymerized wafer T held in the chuck 100 (step St1 in Figure 8).

[0054] Specifically, first, the distance Lw between the length measuring sensor 121 of the displacement detection unit 120 and the outer edge of the first wafer W, and the distance Ls between the outer edges of the second wafer S (see Figure 5) are measured. The measurement result from the length measuring sensor 121 is obtained as a relationship between the distance from the length measuring sensor 121 to the outer edge of the polymerized wafer T (vertical axis) and the position in the thickness direction of the polymerized wafer T, which is the measurement width direction by the length measuring sensor 121 (horizontal axis), as shown in Figure 9 as an example. Data including the distance from the length measuring sensor 121 to the outer edge of the polymerized wafer T is obtained at multiple points in the circumferential direction of the polymerized wafer T, preferably around the entire circumference of the polymerized wafer T. The measurement result from the length measuring sensor 121 is output to the calculation unit 122.

[0055] Once the measurement results from the length measuring sensor 121 are obtained, the calculation unit 122 of the displacement detection unit 120 calculates the positions of the first wafer W and the second wafer S on the chuck 100 based on the distances Lw and Ls obtained from the measurement results. Furthermore, the calculation unit 122 calculates the horizontal displacement between the first wafer W and the second wafer S from the difference between the acquired distances Lw and Ls. In addition, the eccentricity of the first wafer W and the second wafer S (the displacement between the center of the first wafer W and the center of the second wafer S) is calculated from the displacement calculated at multiple points in the circumferential direction of the superimposed wafer T (step St2 in Figure 8). The calculated eccentricity is output to the control device 90.

[0056] The control device 90 acquires the eccentricity between the chuck 100 and the second wafer S, that is, the amount of misalignment between the rotation center of the chuck 100 and the center of the second wafer S. The eccentricity between the chuck 100 and the second wafer S may be acquired using the measurement results from the length measuring sensor 121, or it may be acquired using another eccentricity detection unit (e.g., a camera) not shown. When acquiring the eccentricity between the chuck 100 and the second wafer S using the measurement results from the length measuring sensor 121, for example, the eccentricity between the chuck 100 and the second wafer S can be calculated based on the positional relationship between the length measuring sensor 121 and the rotation center of the chuck 100, which is stored in the control device 90 beforehand, and the distance Ls acquired in step St1, i.e., the position of the second wafer S on the chuck 100.

[0057] Once the eccentricity of the first wafer W and the second wafer S is calculated, the interface laser beam L1 is then pulsed from the laser irradiation unit 110 onto a preset irradiation area to modify the interface between the first wafer W and the second wafer S (in the illustrated example, the interface between the second wafer S and the bonding film Fs) as shown in Figures 3 and 10(a). In this embodiment, the interface laser beam L1 is irradiated from the back surface Sb side of the second wafer S toward the polymerized wafer T. In this embodiment, "interface modification" includes amorphization of the device layers Dw and Ds and bonding films Fw and Fs at the irradiation position of the interface laser beam L1, and delamination of the first wafer W and the second wafer S.

[0058] The irradiation area of ​​the interface laser beam L1 is determined as an annular region with a desired radial width, with respect to the outer edge of the second wafer S, as shown as an example in Figure 10(a). The radial width of the irradiation area of ​​the interface laser beam L1 is set to a width that can appropriately remove the peripheral portion We of the first wafer W to be removed. In other words, in the edge trimming of the first wafer W according to this embodiment, a bonding force reduction region Ae is formed at a desired position with respect to the outer edge of the second wafer S. In this embodiment, the position of the outer edge of the second wafer S, which serves as the reference for the irradiation area of ​​the interface laser beam L1, is acquired in advance based on the measurement result (distance Ls) by the length measuring sensor 121 of the displacement amount detection unit 120 described above, so that the irradiation area of ​​the interface laser beam L1 can be appropriately detected. Furthermore, in this embodiment, as described above, the positional relationship between the length measuring sensor 121 and the lens 113 of the laser irradiation unit 110 is stored in advance. Based on this positional relationship and the measurement result (distance Ls) from the length measuring sensor 121, the irradiation position of the interface laser beam L1 can be appropriately set within the irradiation area.

[0059] Furthermore, the interface laser beam L1 is irradiated onto the irradiation area of ​​the interface laser beam L1 from above the second wafer S while rotating the chuck 100 (polymerized wafer T). At this time, if there is a misalignment between the rotation center of the chuck 100 and the center of the second wafer S, there is a risk that the interface laser beam L1 may not be properly irradiated onto the determined irradiation area. Similarly, if there is a horizontal misalignment between the first wafer W and the second wafer S at this time, there is a risk that the interface laser beam L1 may not be properly irradiated.

[0060] Therefore, in the interface modification apparatus 50 according to this embodiment, the eccentricity of the first wafer W and the second wafer S, and the eccentricity of the second wafer S and the chuck 100, calculated in step St2, are taken into consideration, and the interface laser light L1 is irradiated while correcting the eccentricity. That is, the chuck 100 (polymerized wafer T) is rotated, and the chuck 100 is moved horizontally along the Y-axis to correct the calculated eccentricity, while the interface laser light L1 is irradiated onto the interface between the first wafer W and the second wafer S.

[0061] In the interface modification apparatus 50, by modifying the irradiation position of the interface laser light L1 at the interface between the first wafer W and the second wafer S, a bonding strength reduction region Ae is formed in which the bonding strength between the first wafer W and the second wafer S is reduced (step St3 in Figure 8). In the edge trimming described later, the peripheral portion We of the first wafer W, which is to be removed, is removed, and the presence of this bonding strength reduction region Ae allows for the proper removal of this peripheral portion We.

[0062] Furthermore, in this embodiment, when forming the bonding force reduction region Ae in the interface modification apparatus 50, the chuck 100 is moved horizontally along the Y-axis direction to correct not only the eccentricity between the chuck 100 and the second wafer S, but also the eccentricity between the first wafer W and the second wafer S. This makes it possible to appropriately form the bonding force reduction region Ae in the irradiation area of ​​the desired interface laser light L1, even when the polymerized wafer T (first wafer W) is held eccentrically in the chuck 100, or when there is a misalignment between the first wafer W and the second wafer S.

[0063] The polymerized wafer T, in which a bonding force reduction region Ae is formed at the interface between the first wafer W and the second wafer S, is then transported to the inversion device 31 by the wafer transport device 40. In the inversion device 31, the front and back surfaces of the polymerized wafer T are inverted, so that the polymerized wafer T is in a state where the first wafer W is facing upwards.

[0064] The polymerized wafer T, with its front and back sides reversed, is then transported to the internal modification apparatus 60 by the wafer transport device 40. The chuck 200 of the internal modification apparatus 60 holds the back surface Sb of the second wafer S by adsorption across its entire surface, with the first wafer W positioned on top and the second wafer S on the bottom.

[0065] In the internal modification apparatus 60, first, the position of the polymerized wafer T held in the chuck 200, that is, the distances Lw and Ls between the length sensor 221 and the first wafer W and the second wafer S, are measured using the length measuring sensor 221 of the displacement detection unit 220 (step St4 in Figure 8). The measurement results from the length measuring sensor 221 are output to the calculation unit 222.

[0066] The control device 90 also acquires the eccentricity between the chuck 200 and the first wafer W, that is, the amount of misalignment between the rotation center of the chuck 200 and the center of the first wafer W. The eccentricity between the chuck 200 and the first wafer W may be acquired using the measurement results from the length measuring sensor 221, or it may be acquired using another eccentricity detection unit (e.g., a camera) not shown. When acquiring the eccentricity between the chuck 200 and the first wafer W using the measurement results from the length measuring sensor 221, for example, the eccentricity between the chuck 200 and the first wafer W can be calculated based on the positional relationship between the length measuring sensor 221 and the chuck 200, which is stored in the control device 90 beforehand, and the distance Lw acquired by the length measuring sensor 221, i.e., the position of the first wafer W on the chuck 200.

[0067] Next, the internal laser beam L2 is irradiated from the laser irradiation unit 210 to a predetermined irradiation position for the internal laser beam L2, and as shown in Figures 3 and 10(b), a peripheral modification layer M1 and a segmented modification layer M2 are sequentially formed inside the first wafer W (step St5 in Figure 8). In this embodiment, the internal laser beam L2 is irradiated from the back surface Wb side of the first wafer W toward the polymerized wafer T. The peripheral modification layer M1 serves as a base point when removing the peripheral portion We in the edge trimming described later. The segmented modification layer M2 serves as a base point for fragmenting the peripheral portion We to be removed. Note that in the drawings used in the following explanation, the illustration of the segmented modification layer M2 may be omitted to avoid complexity in the illustration.

[0068] The irradiation position of the internal laser beam L2, i.e., the formation position of the peripheral modification layer M1, is determined, for example, slightly radially inward from the radially inward end of the bonding force reduction region Ae formed in step St3, with respect to the outer edge of the second wafer S. In other words, in the edge trim of the first wafer W according to this embodiment, the peripheral modification layer M1 is formed at a desired position with respect to the outer edge of the second wafer S. In this embodiment, the position of the outer edge of the second wafer S, which serves as the reference for the formation position of the peripheral modification layer M1, is acquired in advance based on the measurement result (distance Ls) from the length measuring sensor 221 described above, and the positional relationship between the length measuring sensor 221 and the lens 213 of the laser irradiation unit 210 is stored in advance, so the irradiation position of the internal laser beam L2 can be appropriately aligned to the desired position.

[0069] Furthermore, the internal laser beam L2 is irradiated onto the chuck 200 (polymerized wafer T) while rotating it. If there is a misalignment between the rotation center of the chuck 200 and the center of the first wafer W, there is a risk that the internal laser beam L2 may not be properly irradiated onto the determined irradiation position. Similarly, if there is a horizontal misalignment between the first wafer W and the second wafer S, there is a risk that the internal laser beam L2 may not be properly irradiated.

[0070] Therefore, in the internal modification apparatus 60 according to this embodiment, the internal laser beam L2 is irradiated while correcting the eccentricity, taking into consideration the eccentricity of the first wafer W and the second wafer S calculated in step St2, and the eccentricity of the first wafer W and the chuck 200 calculated in step St4. That is, the internal laser beam L2 is irradiated into the interior of the first wafer W while rotating the chuck 200 (polymerized wafer T) and moving the chuck 200 horizontally along the Y-axis to correct the calculated eccentricity.

[0071] In the internal modification apparatus 60, the chuck 200 is moved horizontally along the Y-axis to correct not only the eccentricity between the chuck 200 and the first wafer W, but also the eccentricity between the first wafer W and the second wafer S. This allows the peripheral modification layer M1 to be properly formed at the desired position, even when the polymerized wafer T is held eccentrically in the chuck 200, or when there is a misalignment between the first wafer W and the second wafer S.

[0072] The polymerized wafer T, in which a peripheral modification layer M1 and a segmented modification layer M2 are formed inside the first wafer W, is then transported to the peripheral removal device 70 by the wafer transport device 40. In the peripheral removal device 70, as shown in Figure 10(c), the peripheral portion We of the first wafer W is removed, i.e., edge trimming is performed (step St6 in Figure 8).

[0073] For removing the peripheral portion We, as an example, as shown in Figure 10(c), a blade B, for example, having a wedge shape, may be inserted at the interface between the first wafer W and the second wafer S that form the polymerized wafer T. The insertion position of the blade B relative to the interface between the first wafer W and the second wafer S can be determined, for example, based on the measurement results in step St1. Specifically, as shown in Figure 9, the measurement results in step St1 are acquired as data showing the relationship between the distance from the length measuring sensor 121 of the displacement detection unit 120 to the outer edge of the polymerized wafer T and the position of the polymerized wafer T in the thickness direction. In other words, the measurement results in step St1 provide data on the edge position of the polymerized wafer T (the outline of the outer edge of the polymerized wafer T) in the thickness direction of the polymerized wafer T, and based on this, the position of the bonding interface between the first wafer W and the second wafer S can be detected. The peripheral removal device 70 can then appropriately determine the insertion position of the blade B based on the position of the bonding interface between the first wafer W and the second wafer S, which has been detected in this manner.

[0074] When the blade B is inserted into the interface between the first wafer W and the second wafer S, the peripheral portion We of the first wafer W is peeled away from the central portion Wc of the first wafer W, starting from the peripheral modification layer M1, and is completely peeled away from the second wafer S, starting from the bonding force reduction region Ae. At this time, the removed peripheral portion We is also broken into smaller pieces, starting from the segmentation modification layer M2.

[0075] The polymerized wafer T, from which the peripheral We of the first wafer W has been removed, is then transported to the cleaning device 80 by the wafer transport device 40. In the cleaning device 80, the first wafer W and / or the second wafer S, after the peripheral We has been removed, are cleaned (step St7 in Figure 8).

[0076] The cleaning method using the cleaning device 80 can be determined arbitrarily. For example, the first wafer W and the second wafer S may be scrubbed by bringing a brush into contact with them. A pressurized cleaning solution may also be used to clean the first wafer W and the second wafer S.

[0077] Subsequently, the polymerized wafer T, after all processing has been completed, is transported to the transition device 30 by the wafer transport device 40, and then transported to the cassette C on the cassette stand 10 by the wafer transport device 20. In this way, the series of wafer processing operations in the wafer processing system 1 is completed.

[0078] Furthermore, the polymerized wafer T, which has undergone edge trimming of the first wafer W, may be inspected (quality inspection) to determine whether the edge trimming was performed properly, that is, whether the peripheral portion We was removed from the first wafer W with the desired trim width. An inspection device (not shown) for performing the quality inspection of the edge trimming may be configured integrally with the peripheral removal device 70, for example, or it may be arranged independently outside the peripheral removal device 70. In addition, the inspection device (not shown) may be arranged inside or outside the wafer processing system 1.

[0079] As described above, according to the edge trimming method of this embodiment, in the interface modification apparatus 50 for forming the bonding force reduction region Ae, and the internal modification apparatus 60 for forming the peripheral modification layer M1 and the divided modification layer M2, displacement detection units 120 and 220 equipped with length measuring sensors 121 and 221 are arranged to the sides of the chucks 100 and 200 that hold the polymerized wafer T, respectively. Conventionally, when detecting the position of the polymerized wafer T from above the chuck using a vision system such as a camera, it was difficult to accurately determine the edge position of the polymerized wafer T due to the film quality and film blemishes of the first wafer W and the second wafer S, and therefore difficult to detect the amount of displacement between the first wafer W and the second wafer S. In this respect, according to this embodiment, since length measuring sensors 121 and 221 such as interferometers and displacement meters are used, the position of the polymerized wafer T on the chucks 100 and 200 can be appropriately detected regardless of the film quality, film mottling, etc., of the first wafer W and the second wafer S, and the amount of displacement (eccentricity) between the first wafer W and the second wafer S can be appropriately calculated.

[0080] In the wafer processing system 1 according to the above embodiment, the position of the polymerized wafer T on the chucks 100 and 200 was appropriately detected and the laser beam irradiation position was aligned to the desired position using only the displacement detection units 120 and 220, which include the length measuring sensors 121 and 221, which are arranged in the interface modification device 50 or the internal modification device 60.

[0081] However, instead of determining the laser beam irradiation position using only the displacement detection units 120 and 220, the interface modification apparatus 50 and the internal modification apparatus 60 may further have an imaging mechanism (e.g., a camera) for detecting the position of the polymerized wafer T from above the chucks 100 and 200. In this case, the interface modification apparatus 50 and the internal modification apparatus 60 may use the imaging mechanism to detect the edge position of the polymerized wafer T and determine the laser beam irradiation position, and use the displacement detection units 120 and 220 to detect the displacement between the first wafer W and the second wafer S. In this case, it is desirable that the positional relationship between the imaging mechanism and the length measuring sensors 121 and 221 of the displacement detection units 120 and 220 be stored in the control device 90 in advance.

[0082] Figure 11 is a plan view showing a schematic configuration of the interface modification apparatus 50a and internal modification apparatus 60a according to another embodiment equipped with imaging mechanisms 130 and 230. In the following description, in the configurations of the interface modification apparatus 50a and internal modification apparatus 60a, elements having substantially the same functional configuration as the interface modification apparatus 50 and internal modification apparatus 60 shown in Figure 4 are denoted by the same reference numerals, and detailed explanations are omitted. Also, as shown in Figure 11, the configurations of the interface modification apparatus 50a and internal modification apparatus 60a are similar, so in the following description, the configuration of the interface modification apparatus 50a will be described as a representative example.

[0083] The interface modification apparatus 50a includes a chuck 100 for holding the polymerized wafer T on its upper surface, a laser irradiation unit 110 positioned above the chuck 100, and a displacement detection unit 120 positioned to the side of the chuck 100.

[0084] Furthermore, the interface modification apparatus 50a, in addition to the above configuration of the interface modification apparatus 50 shown in Figure 4, includes an imaging mechanism 130 for imaging the outer edge of the polymerized wafer T held in the chuck 100. The imaging mechanism 130 is positioned so as to be able to image the position detected by the displacement amount detection unit 120 on the outer edge of the polymerized wafer T from above. That is, the imaging mechanism 130 is positioned above the chuck 100, at the same position in the Y-axis direction as the length measuring sensor 121 of the displacement amount detection unit 120, and on the positive X-axis side. The imaging mechanism 130 may be configured to be able to move up and down by a lifting mechanism (not shown). It is desirable that the positional relationship between the imaging mechanism 130 and the lens 113 of the laser irradiation unit 110 be stored in the control device 90 in advance.

[0085] The imaging mechanism 130 includes one or more cameras, selected as an example from a macro camera or a micro camera, and images the outer edge of the polymerized wafer T held in the chuck 100. The imaging mechanism 130 includes, for example, a coaxial lens, and irradiates light that is transparent to at least the first wafer W and the second wafer S, such as infrared light (IR), and also receives reflected light from the object.

[0086] In the interface modification apparatus 50a, while rotating the chuck 100, the imaging mechanism 130 captures images of the outer edges of the polymerized wafer T (in the example of the above embodiment, the second wafer S positioned on the upper side of the chuck 100) in a 360-degree circumferential direction. The captured images are output from the imaging mechanism 130 to the control device 90. The control device 90 calculates the eccentricity between the rotation center of the chuck 100 and the center of the second wafer S from the image of the imaging mechanism 130, and moves the chuck 100 in the Y-axis direction to correct the Y-axis component of the eccentricity based on the calculated eccentricity.

[0087] Furthermore, the control device 90 sets the irradiation area for the interface laser light L1 to form the bonding force reduction region Ae from the image captured by the imaging mechanism 130. The irradiation area for the interface laser light L1 is determined, for example, as an annular region with a desired radial width, based on the outer edge of the second wafer S detected from the image captured by the imaging mechanism 130. And interface modifier 50a Next, after the displacement amount of the first wafer W and the second wafer S is detected using the displacement amount detection unit 120, the interface laser light L1 is irradiated from the laser irradiation unit 110 to the determined irradiation area to form a bonding force reduction area Ae. In this embodiment, as described above, the positional relationship between the imaging mechanism 130 and the lens 113 of the laser irradiation unit 110 is stored in the control device 90 in advance, so the irradiation position of the interface laser light L1 by the laser irradiation unit 110 can be appropriately set within a predetermined irradiation area.

[0088] Thus, in the wafer processing system 1 according to this embodiment, the imaging mechanisms 130 and 230 for detecting the position of the polymerized wafer T (first wafer W and / or second wafer S) on the chuck and the displacement detection units 120 and 220 may be arranged independently, as shown in the interface modification apparatus 50a and internal modification apparatus 60a in Figure 11. As a result, compared to the case where the irradiation position of the laser beam is determined using only the displacement detection units 120 and 220, the bonding force reduction region Ae and the peripheral modified layer M1 can be formed more appropriately, and the throughput for forming these bonding force reduction region Ae and peripheral modified layer M1 can be improved.

[0089] In the above embodiment, as shown in Figure 10(a), when forming the bonding force reduction region Ae in the interface modification apparatus 50, the interface laser light L1 was irradiated from the second wafer S side. However, the interface laser light L1 may be irradiated from the first wafer W side. In this case, as shown as an example in Figure 12(a), the bonding force reduction region Ae is formed at the interface between the first wafer W and the bonding film Fw. Then, as shown in Figure 12(b), the internal laser light L2 is irradiated from the first wafer W side to form the peripheral modification layer M1 and the divided modification layer M2 inside the first wafer W. Furthermore, as shown in Figure 12(c), the peripheral portion We is removed using the peripheral modification layer M1 and the bonding force reduction region Ae as starting points.

[0090] Furthermore, the polymerized wafer T from which the peripheral portion We of the first wafer W has been removed may be irradiated with a cleaning laser L3 (e.g., a femtosecond laser) to remove the surface film (bonding films Fw, Fs and device layers Dw, Ds) remaining on the surface Sa of the second wafer S, as shown in Figure 12(d). Alternatively, the surface film may be removed by, for example, blasting or etching.

[0091] In the above embodiment, the formation of the bonding force reduction region Ae on the polymerized wafer T (step St3) and the formation of the peripheral modified layer M1 and the segmented modified layer M2 (step St5) were performed in this order, but the order of these formations is not particularly limited. In other words, after forming a peripheral modification layer M1 and a segmented modification layer M2 inside the first wafer W in the internal modification apparatus 60, a bonding force reduction region Ae may be formed at the interface between the first wafer W and the second wafer S in the interface modification apparatus 50. In this case, the detection of the horizontal displacement between the first wafer W and the second wafer S (the eccentricity between the first wafer W and the second wafer S) (step St1) can be performed by the displacement detection unit 220 of the internal modification apparatus 60 instead of the displacement detection unit 120 of the interface modification apparatus 50.

[0092] Furthermore, in the above embodiment, a bonding force reduction region Ae was formed (step St3) to reduce the bonding force between the first wafer W and the second wafer S, but the formation of this bonding force reduction region Ae can be omitted as appropriate. Specifically, the peripheral modification layer M1, which serves as the starting point for removing the peripheral portion We, is formed to correspond to the chamfered portion at the outer edge of the first wafer W, as shown in Figure 13. In other words, at the bonding interface between the first wafer W and the second wafer S, the unbonded region Ae', which is substantially not bonded due to the chamfered portion formed on the peripheral edges of both wafers, is considered the bonding force reduction region Ae, and the edge trimming of the first wafer W may be performed by forming the peripheral modification layer M1 to correspond to the radially inner end of the chamfered portion. The chamfered portion (unbonded region Ae') of the first wafer W and the second wafer S, which is considered to be the bonding force reduction region Ae, can be detected based on the measurement results from the length measuring sensor 121 of the displacement amount detection unit 120 shown in Figures 5 and 9 (in the example shown in Figure 5, the measurement result from the central measuring light out of the three measuring lights emitted from the length measuring sensor 121). In other words, the irradiation position of the internal laser light L2, i.e., the formation position of the peripheral modification layer M1, may be determined based on the position of the radially inner end of the unbonded region Ae' detected from the measurement results from the length measuring sensor 121.

[0093] As shown in the example in Figure 13, the peripheral portion We of the first wafer W is peeled off from the central portion Wc of the first wafer W, with the peripheral modification layer M1 as the starting point. Furthermore, radially outside the formation position of the peripheral modification layer M1, the first wafer W and the second wafer S are not substantially joined due to the formation of a chamfered portion, so the peripheral portion We can be properly removed from the second wafer S. Furthermore, according to this example, since it is not necessary to form a bonding force reduction region Ae in the interface modification apparatus 50 when trimming the edge of the first wafer W, the throughput related to edge trimming can be significantly improved.

[0094] As shown in Figure 13, when the peripheral modification layer M1 is formed by irradiation with the internal laser beam L2, a crack C1 extends from the peripheral modification layer M1 in the thickness direction of the first wafer W into the interior of the first wafer W. More specifically, during edge trimming by the peripheral removal apparatus 70, the peripheral portion We is peeled off from the central portion Wc, using the peripheral modification layer M1 and the crack C1 as starting points. Therefore, the irradiation position of the internal laser beam L2, i.e., the formation position of the peripheral modification layer M1, may be controlled to be slightly radially inward from the radially inward end of the unbonded region Ae', as shown in Figure 14. In this case, by extending a crack C1 diagonally from the peripheral modification layer M1 toward the radially inward end of the unbonded region Ae', the peripheral portion We can be appropriately removed from the polymerized wafer T.

[0095] Furthermore, this method of controlling the direction of crack C1 propagation from the peripheral modified layer M1 is also applicable when forming a bonding strength reduction region Ae as shown in Figures 10 and 12. That is, in the examples shown in Figures 10 and 12, the formation position of the peripheral modified layer M1 was controlled to coincide radially with the inner end of the bonding strength reduction region Ae, but as shown in Figure 14, the peripheral modified layer M1 may be formed slightly radially inward from the inner end of the bonding strength reduction region Ae, causing the crack C1 to propagate diagonally.

[0096] In the above embodiment, the horizontal displacement (eccentricity) of the first wafer W and the second wafer S was obtained using the displacement detection units 120 and 220 of the interface modification apparatus 50 or the internal modification apparatus 60. However, the location where this displacement (eccentricity) is obtained is not limited to this. For example, a displacement detection device (not shown) may be provided in the wafer processing system 1 independently of the interface modification device 50 and the internal modification device 60, and the displacement amount (eccentricity) of the first wafer W and the second wafer S may be acquired by this displacement detection device. Alternatively, for example, in an external bonding apparatus (not shown) that bonds a first wafer W and a second wafer S, the amount of displacement (eccentricity) between the first wafer W and the second wafer S may be acquired in advance, and the data of the amount of displacement (eccentricity) may be output from these external devices to the control device 90 when the polymerized wafer T is brought into the wafer processing system 1.

[0097] Furthermore, as described above, when acquiring displacement data from an external device of the wafer processing system 1, the interface modification device for forming the bonding force reduction region Ae, and the internal modification device for forming the peripheral modification layer M1 and the divided modification layer M2, require the placement of imaging mechanisms (imaging mechanisms 130 and 230 in Figure 11) for detecting the outer edge of the polymerized wafer T, which serves as a reference for determining the irradiation position of the interface laser beam L1 and the internal laser beam L2.

[0098] Next, an edge trimming method for the first wafer W according to another embodiment will be described with reference to the drawings. In the edge trimming method according to the other embodiment, the irradiation positions of the interface laser beam L1 and the internal laser beam L2 are aligned using the outer edge of the first wafer W as the reference, instead of the outer edge of the second wafer S. In the following description, detailed explanations of processes that are substantially the same as those in the above embodiment using the outer edge of the second wafer S as the reference will be omitted.

[0099] First, a cassette C containing multiple polymerized wafers T is placed on the cassette platform 10 of the loading / unloading station 2. Next, the polymerized wafers T in the cassette C are removed by the wafer transport device 20 and transported to the interface modification device 50 via the transition device 30 and the wafer transport device 40. At this time, if the polymerized wafer T is contained in cassette C with the second wafer S facing upwards, the polymerized wafer T is directly transported from cassette C to the interface modification apparatus 50. On the other hand, if the polymerized wafer T is contained in cassette C with the first wafer W facing upwards, the front and back surfaces of the polymerized wafer T are inverted via the inversion device 31 before being transported to the interface modification apparatus 50. In other words, the chuck 100 of the interface modification apparatus 50 holds the entire back surface Wb of the first wafer W by adsorption when the second wafer S is positioned on top and the first wafer W is positioned on the bottom.

[0100] In the interface modification apparatus 50, first, the displacement amount detection unit 120 is used to detect the horizontal displacement amount (eccentricity of the first wafer W and the second wafer S) of the first wafer W and the second wafer S that constitute the polymerized wafer T held in the chuck 100 (step St1 in Figure 8). The method for detecting the horizontal displacement amount of the first wafer W and the second wafer S is the same as in the above embodiment. The measurement result from the length measuring sensor 121 is output to the calculation unit 122.

[0101] The calculation unit 122 calculates the outer edge positions of the first wafer W and the second wafer S on the chuck 100 based on the measurement results in step St1. Furthermore, the calculation unit 122 calculates the horizontal displacement between the first wafer W and the second wafer S, and the eccentricity between the first wafer W and the second wafer S, from the difference between the acquired distance Lw and distance Ls (step St2 in Figure 8). The calculated eccentricity is output to the control device 90.

[0102] The control device 90 calculates the eccentricity between the chuck 100 and the second wafer S, that is, the amount of misalignment between the rotation center of the chuck 100 and the center of the second wafer S.

[0103] Next, the interface laser beam L1 is pulsed from the laser irradiation unit 110 onto a preset irradiation area, forming a bonding force reduction region Ae at the interface between the first wafer W and the second wafer S (in the illustrated example, the interface between the second wafer S and the bonding film Fs) as shown in Figures 3 and 15(a) (step St3 in Figure 8). In one example, the interface laser beam L1 is irradiated from the second wafer S side toward the polymerized wafer T.

[0104] In this embodiment, the irradiation area of ​​the interface laser beam L1 is determined as an annular region having a desired radial width, with respect to the outer edge of the first wafer W, as shown in Figure 15(a). The radial width of the irradiation area of ​​the interface laser beam L1 is set to a width that can appropriately remove the peripheral portion We of the first wafer W to be removed. In other words, in the edge trimming of the first wafer W according to this embodiment, a bonding force reduction region Ae is formed at a desired position with respect to the outer edge of the first wafer W. In this embodiment, the position of the outer edge of the first wafer W, which serves as the reference for the irradiation area of ​​the interface laser beam L1, is acquired in advance based on the measurement result (distance Lw) by the length measuring sensor 121 of the displacement amount detection unit 120 described above, so that the irradiation area of ​​the interface laser beam L1 can be appropriately detected. Furthermore, in this embodiment, as described above, the positional relationship between the length measuring sensor 121 and the lens 113 of the laser irradiation unit 110 is stored in advance. Based on this positional relationship and the measurement result (distance Lw) from the length measuring sensor 121, the irradiation position of the interface laser beam L1 can be appropriately set within the irradiation area.

[0105] Furthermore, in this embodiment, as described above, the displacement detection unit 120, which includes a length measuring sensor 121 provided on the side of the chuck 100, is used to independently detect the outer edges of the first wafer W and the second wafer S. Therefore, compared to the conventional method of observing the displacement of the second wafer S from above the polymerized wafer T, for example, the alignment of the irradiation position of the interface laser beam L1 with respect to the outer edge of the second wafer S can be appropriately performed.

[0106] The irradiation of the polymerized wafer T with the interface laser light L1 may be performed from the second wafer S side as described above, or from the first wafer W side.

[0107] The polymerized wafer T, in which a bonding force reduction region Ae is formed at the interface between the first wafer W and the second wafer S, is then transported to the inversion device 31 by the wafer transport device 40. In the inversion device 31, the front and back surfaces of the polymerized wafer T are inverted, so that the first wafer W is facing upwards.

[0108] The polymerized wafer T, with its front and back sides reversed, is then transported to the internal modification apparatus 60 by the wafer transport device 40. The chuck 200 of the internal modification apparatus 60 holds the back surface Sb of the second wafer S by adsorption across its entire surface, with the first wafer W positioned on top and the second wafer S on the bottom.

[0109] In the internal modification apparatus 60, first, the position of the polymerized wafer T held in the chuck 200 is detected using the length measuring sensor 221 of the displacement amount detection unit 220 (step St4 in Figure 8). The measurement result from the length measuring sensor 221 is output to the calculation unit 222. The eccentricity amount calculated by the calculation unit 222 is also output to the control device 90. The control device 90 also acquires the eccentricity between the chuck 200 and the second wafer S, that is, the amount of misalignment between the rotation center of the chuck 200 and the center of the second wafer S.

[0110] Next, the internal laser beam L2 is irradiated from the laser irradiation unit 210 to a predetermined irradiation position for the internal laser beam L2, and as shown in Figures 3 and 15(b), a peripheral modification layer M1 and a segmented modification layer M2 are sequentially formed inside the first wafer W (step St5 in Figure 8). In one example, the internal laser beam L2 is irradiated from the first wafer W side toward the polymerized wafer T.

[0111] The irradiation position of the internal laser beam L2, i.e., the formation position of the peripheral modification layer M1, is determined, for example, slightly radially inward from the radially inward end of the bonding force reduction region Ae formed in step St3, with respect to the outer edge of the first wafer W. In other words, in the edge trim of the first wafer W according to this embodiment, the peripheral modification layer M1 is formed at a desired position with respect to the outer edge of the first wafer W. In this embodiment, the position of the outer edge of the first wafer W, which serves as the reference for the formation position of the peripheral modification layer M1, is acquired in advance based on the measurement result (distance Lw) from the length measuring sensor 221 described above, and the positional relationship between the length measuring sensor 221 and the lens 213 of the laser irradiation unit 210 is stored in advance, so that the irradiation position of the internal laser beam L2 can be appropriately aligned to the desired position.

[0112] The polymerized wafer T, in which a peripheral modification layer M1 and a segmented modification layer M2 are formed inside the first wafer W, is then transported to the peripheral removal device 70 by the wafer transport device 40. In the peripheral removal device 70, as shown in Figure 15(c), the peripheral portion We of the first wafer W is removed, i.e., edge trimming is performed (step St6 in Figure 8). The removal of the peripheral portion We may be performed by inserting blade B into the interface between the first wafer W and the second wafer S, and the insertion position of blade B may be determined based on the measurement results in step St1.

[0113] The polymerized wafer T, from which the peripheral We of the first wafer W has been removed, is then transported to the cleaning device 80 by the wafer transport device 40. In the cleaning device 80, the first wafer W and / or the second wafer S, after the peripheral We has been removed, are cleaned (step St7 in Figure 8). Furthermore, if a surface film remains on the surface Sa of the second wafer S after the removal of the peripheral portion We, the surface film may be removed further, as shown in Figure 15(d).

[0114] Subsequently, the polymerized wafer T, after all processing has been completed, is transported to the transition device 30 by the wafer transport device 40, and then transported to the cassette C on the cassette stand 10 by the wafer transport device 20. In this way, the series of wafer processing operations in the wafer processing system 1 is completed.

[0115] Furthermore, the polymerized wafer T, which has undergone edge trimming of the first wafer W, may be subjected to an inspection (quality inspection) to determine whether the edge trimming was performed properly, that is, whether the peripheral portion We was removed from the first wafer W with the desired trim width.

[0116] As described above, in the edge trimming process according to other embodiments, as shown in Figure 15(c), the width of the peripheral portion We removed from the first wafer W (trim width) can be uniformly controlled around the entire circumference of the first wafer W.

[0117] According to the wafer processing system 1 of the technology disclosed herein, since the outer edges of the first wafer W and the second wafer S are detected independently using a length measuring sensor, the irradiation positions of the interface laser beam L1 and the internal laser beam L2 can be determined by arbitrarily selecting whether to use the outer edge of the first wafer W or the outer edge of the second wafer S as a reference, depending on the purpose of wafer processing. The selection of the reference position for the laser beam irradiation position can also be changed, for example, by the control device 90, for each lot housed in the cassette C, or for each wafer processed by the wafer processing system 1.

[0118] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of Symbols]

[0119] 1. Wafer Processing System 60 Internal Modification Device 70. Edge removal device 90 Control device 220 Shift detection unit M1 Peripheral Modified Layer S Second wafer T Polymerized wafer W First wafer Wc central part We Peripheral area

Claims

1. A method for processing a polymerized substrate in which a first substrate and a second substrate are joined together, The process involves detecting the position of the outer edge of the first substrate and the position of the outer edge of the second substrate, and then obtaining the eccentricity of the first substrate and the second substrate based on the detected positions of the outer edges of the first and second substrates. The process involves irradiating the peripheral edge of the first substrate with an internal laser beam along the boundary between the peripheral edge and the central part of the first substrate to form a peripheral modified layer that serves as a starting point for peeling off the peripheral edge, This includes removing the peripheral portion starting from the peripheral modified layer, A processing method for forming the peripheral modified layer, wherein the irradiation position of the internal laser light is determined based on the eccentricity.

2. The position of the outer edge of the first substrate is detected by measuring a first horizontal distance between the length measuring sensor and the outer edge of the first substrate, The position of the outer end of the second substrate is detected by measuring the second horizontal distance between the length measuring sensor and the outer end of the second substrate, Includes, The processing method according to claim 1, wherein the eccentricity is calculated based on the amount of displacement between the first substrate and the second substrate, which is calculated from the difference between the first horizontal distance and the second horizontal distance.

3. The position of the outer edge of the first substrate is detected by imaging the position of the outer edge of the first substrate from above, This includes detecting the position of the outer edge of the second substrate by imaging the position of the outer edge of the second substrate from below, The processing method according to claim 1, wherein the eccentricity is calculated based on the difference between the position of the outer edge of the first substrate and the position of the outer edge of the second substrate as captured in the image.

4. The processing method according to any one of claims 1 to 3, wherein the irradiation position of the internal laser light is determined with reference to the outer edge of the first substrate.

5. At the interface between the first substrate and the second substrate, A bonding region in which the first substrate and the second substrate are joined, An unbonded region is formed corresponding to the chamfered portion formed on the outer end of the first substrate and the outer end of the second substrate. The processing method according to any one of claims 1 to 3, wherein the irradiation position of the internal laser beam is determined with reference to the radially inner end of the unjoined region.

6. The processing method according to any one of claims 1 to 3, wherein the irradiation position of the internal laser light is determined with reference to the outer end of the second substrate.

7. A method for processing a polymerized substrate in which a first substrate and a second substrate are joined together, The process involves detecting the position of the outer edge of the first substrate and the position of the outer edge of the second substrate, and then obtaining the eccentricity of the first substrate and the second substrate based on the detected positions of the outer edges of the first and second substrates. This includes irradiating the interface between the first substrate and the second substrate with an interface laser beam to form a bonding force reduction region at the interface where the bonding force is reduced, A processing method for forming the bonding force reduction region, wherein the irradiation position of the interface laser light is determined based on the eccentricity.

8. The process involves irradiating the peripheral edge of the first substrate with an internal laser beam along the boundary between the peripheral edge and the central part of the first substrate to form a peripheral modified layer that serves as a starting point for peeling off the peripheral edge, This includes removing the peripheral portion starting from the peripheral modified layer, The processing method according to claim 7, wherein the irradiation position of the internal laser light is determined based on the eccentricity when forming the peripheral modified layer.

9. The processing method according to claim 8, wherein the irradiation position of the internal laser light is determined with reference to the outer end of the second substrate.

10. The position of the outer edge of the first substrate is detected by measuring a first horizontal distance between the length measuring sensor and the outer edge of the first substrate, The position of the outer end of the second substrate is detected by measuring the second horizontal distance between the length measuring sensor and the outer end of the second substrate, Includes, The processing method according to any one of claims 7 to 9, wherein the eccentricity is calculated based on the amount of displacement between the first substrate and the second substrate, which is calculated from the difference between the first horizontal distance and the second horizontal distance.

11. The irradiation position of the interface laser light is determined with reference to the outer edge of the first substrate. The processing method according to any one of claims 7 to 9, wherein the interface laser light is irradiated onto the polymerization substrate from the second substrate side.

12. The irradiation position of the interface laser beam is determined with reference to the outer edge of the second substrate. The processing method according to any one of claims 7 to 9, wherein the interface laser light is irradiated onto the polymerization substrate from the first substrate side.

13. A processing system for processing a polymerized substrate in which a first substrate and a second substrate are joined together, A displacement detection device for detecting the position of the outer edge of the first substrate and the position of the outer edge of the second substrate, An internal modification apparatus that irradiates an internal laser beam along the boundary between the peripheral edge of the first substrate and the central part of the first substrate to form a peripheral modification layer that serves as a starting point for peeling off the peripheral edge, A peripheral removal device that removes the peripheral portion starting from the peripheral modified layer, A control device is provided, The control device is A processing system that performs control to determine the irradiation position of the internal laser beam based on an eccentricity amount calculated based on the position of the outer edge of the first substrate and the position of the outer edge of the second substrate detected by the displacement detection device.

14. A processing system for processing a polymerized substrate in which a first substrate and a second substrate are joined together, A displacement detection device for detecting the position of the outer edge of the first substrate and the position of the outer edge of the second substrate, An interface modification apparatus that irradiates the interface between the first substrate and the second substrate with an interface laser beam to form an unbonded region at the interface in which the bonding force is reduced, A control device is provided, The control device is A processing system that performs control to determine the irradiation position of the interface laser beam based on an eccentricity amount calculated based on the position of the outer edge of the first substrate and the position of the outer edge of the second substrate detected by the displacement amount detection device.

15. An internal modification apparatus that irradiates an internal laser beam along the boundary between the peripheral edge of the first substrate and the central part of the first substrate to form a peripheral modification layer that serves as a starting point for peeling off the peripheral edge, A peripheral removal device that removes the peripheral portion starting from the peripheral modified layer, A control device is provided, The processing system according to claim 14, wherein the control device performs control to determine the irradiation position of the internal laser light based on the eccentricity.

16. The control device includes a control that determines the irradiation position of the interface laser light with respect to the outer edge of the first substrate, The processing system according to claim 14 or 15, which performs control to irradiate the polymerization substrate with the interface laser light from the second substrate side.

17. The control device includes a control that determines the irradiation position of the interface laser light with respect to the outer edge of the second substrate, The processing system according to claim 14 or 15, which performs control to irradiate the polymerization substrate with the interface laser light from the first substrate side.

18. A substrate holding portion that holds the polymerized substrate on its upper surface, It has a moving mechanism for moving the substrate holding portion in the horizontal direction, The processing system according to any one of claims 13 to 15, wherein the displacement detection device is positioned opposite to the substrate holder in a direction perpendicular to the direction of movement of the substrate holder, or on the axis of movement of the substrate holder, opposite to the substrate holder.

19. The displacement detection device includes a length measuring sensor positioned to the side of the substrate holding portion that holds the polymerized substrate, The control device is Control to detect the position of the outer edge of the first substrate by measuring a first horizontal distance between the length measuring sensor and the outer edge of the first substrate, Control to detect the position of the outer end of the second substrate by measuring the second horizontal distance between the length measuring sensor and the outer end of the second substrate, A processing system according to any one of claims 13 to 15, comprising: performing control to calculate the eccentricity amount based on the amount of displacement between the first substrate and the second substrate calculated from the difference between the first horizontal distance and the second horizontal distance.

20. The aforementioned displacement detection device is A first imaging mechanism for imaging the position of the outer end of the first substrate from above, The system includes a second imaging mechanism that images the position of the outer end of the second substrate from below, The processing system according to any one of claims 13 to 15, wherein the control device performs control to calculate the eccentricity based on the difference between the position of the outer edge of the first substrate and the position of the outer edge of the second substrate as captured.

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