Processing Method and Processing System

Abstract

To provide a processing method which appropriately improves productivity relating to removal of a peripheral edge part of a first wafer in a polymerized wafer configured by combining the first wafer and a second wafer, and a processing system.SOLUTION: The present invention relates to a processing method for a polymerized wafer T configured by combining a first wafer and a second wafer. A peripheral edge part We of the first wafer of a removal object includes: a combined area Ac combined with the second wafer; and a non-combined area AE which is not combined with the second wafer radially outside of the combination area. The processing method includes: forming a peripheral edge modification layer M1 to be a base point of pealing of the peripheral edge part along a boundary of the peripheral edge part We of the first wafer and a central part of the first wafer; detecting a boundary position of the combined area and the non-combined area over a whole circumference of the first wafer; irradiating the side closer to the combined area than the detected boundary position with laser beams and forming a combination strength reduction region R where, combination strength of the first wafer and the second wafer is reduced; and peeling the peripheral edge part from the polymerized wafer with the peripheral edge modification layer defined as the base point.SELECTED DRAWING: Figure 7

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 removal 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 improves the productivity related to the removal of 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 polymer substrate in which a first substrate and a second substrate are bonded. The peripheral portion of the first substrate to be removed has a bonded region bonded to the second substrate and an unbonded region not bonded to the second substrate outside the bonded region in the radial direction. Along the boundary between the peripheral portion of the first substrate and the central portion of the first substrate, a peripheral modification layer serving as a base point for peeling the peripheral portion is formed. The boundary position between the bonded region and the unbonded region is detected over the entire circumference of the first substrate. A laser beam is irradiated on the bonded region side of the detected boundary position to form a bonding force reduction region for reducing the bonding force between the first substrate and the second substrate. The peripheral portion is peeled from the polymer substrate with the peripheral modification layer as a base point. determining, as a reference position, the boundary position among the boundary positions detected throughout the circumference that is closest to the outer peripheral end portion of the first substrate, and irradiating the laser light onto an annular region on the bonding region side from the reference position in forming the bonding strength reduction region.

Advantages of the Invention

[0006] According to the present disclosure, in a polymer substrate in which a first substrate and a second substrate are bonded, the productivity related to the removal of the peripheral portion of the first substrate can be appropriately improved.

Brief Description of the Drawings

[0007]

Figure 1A

Figure 1B

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8A

Figure 8B

Figure 9A

Figure 9B

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0008] In the manufacturing process of a semiconductor device, in a polymerized substrate in which a first substrate (a silicon substrate such as a semiconductor) having devices such as a plurality of electronic circuits formed on its surface and a second substrate are joined, the peripheral portion of the first wafer may be removed, that is, so-called edge trimming may be performed.

[0009] The edge trimming of the first substrate is performed, for example, using the substrate processing system disclosed in Patent Document 1. That is, a modified layer is formed by irradiating a laser beam inside the first substrate, and the peripheral portion is removed from the first substrate with the modified layer as a base point. Further, according to the substrate processing system described in Patent Document 1, a modified surface is formed by irradiating a laser beam on the interface where the first substrate and the second substrate are joined, thereby reducing the bonding strength between the first substrate and the second substrate at the peripheral portion and appropriately removing the peripheral portion.

[0010] Incidentally, chamfering is performed on the end of the first substrate including the peripheral edge portion to be removed in edge trimming, and the thickness decreases toward the tip. Therefore, in the polymerized substrate in which the first substrate and the second substrate are joined, the first substrate and the second substrate do not contact each other at the chamfered portion where the thickness has decreased, and joining is not performed. Further, even in a region radially inward of such a chamfered portion, for example, due to various factors such as the result of substrate processing in the previous process and the conditions at the time of joining the first substrate and the second substrate, a region where the first substrate and the second substrate are not joined may occur. Further, even in a region radially outward of such a chamfered portion, a region where the first substrate and the second substrate are joined may similarly occur.

[0011] In the following description, a region where the first substrate and the second substrate are not joined at the peripheral edge of the first substrate may be referred to as an "unjoined region". Also, a region where the first substrate and the second substrate are joined may be referred to as a "joined region". As described above, the unjoined region may occur radially inward of the chamfered portion of the first substrate. However, in order to suppress the explanation from becoming complicated, hereinafter, the unjoined portion corresponding to the chamfered portion will be referred to as "unjoined region Ae", the joined portion radially inward of the unjoined region Ae will be referred to as "joined region Ac", and the boundary portion between the unjoined region Ae and the joined region Ac will be referred to as "boundary Ad" (see FIGS. 1A and 1B described later).

[0012] Since the first substrate and the second substrate are not joined in such an unjoined region, it is not necessary to reduce the bonding force by irradiating the laser light as described above. However, Patent Document 1 does not describe considering such an unjoined region (the chamfered portion of the substrate). When the laser light is thus irradiated even on the unjoined region, the laser light is irradiated on a portion where the laser light is not originally required. Therefore, in the conventional edge trimming method, there is room for improvement from the viewpoint of improving productivity (throughput).

[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 productivity related to the removal of the peripheral portion of the first substrate is appropriately improved. 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 FIGS. 1A and 1B, processing is performed on a polymer wafer T as a polymer substrate in which a first wafer W as a first substrate and a second wafer S as a second substrate are joined. 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, for example, and a device layer Dw including a plurality of devices is formed on the front surface Wa side. Further, a bonding film Fw is formed on the device layer Dw, and the first wafer W is bonded to the second wafer S via 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 the tip. Further, the peripheral portion We is a portion to be removed in the edge trim 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.

[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. Note that the second wafer S does not necessarily have to be a device wafer on which the device layer Ds is formed, and it 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. 1B, at the bonding interface between the first wafer W and the second wafer S, a bonded region Ac where the first wafer W and the second wafer S are bonded and an unbonded region Ae where the first wafer W and the second wafer S are not bonded are formed. In FIG. 1B, the case where the unbonded region Ae substantially coincides with the chamfered regions of the first wafer W and the second wafer S is illustrated as an example. However, as described above, the unbonded region Ae can also be formed radially inside the boundary Ad shown in FIG. 1B. Similarly, the bonded region Ac can also be formed radially outside the boundary Ad shown in FIG. 1B.

[0018] As shown in FIG. 2, the wafer processing system 1 has a configuration in which a loading / unloading station 2 and a processing station 3 are integrally connected. At the loading / unloading station 2, for example, a cassette C capable of accommodating a plurality of polymer wafers T is loaded and unloaded to and from the outside. The processing station 3 is provided with various processing apparatuses that perform desired processing on the polymer wafers T.

[0019] The loading / unloading station 2 is provided with a cassette mounting table 10 on which a cassette C capable of accommodating a plurality of polymer wafers T is placed. Further, on the positive X-axis side of the cassette mounting table 10, a wafer transfer device 20 is provided adjacent to the cassette mounting table 10. The wafer transfer device 20 is configured to move on a transfer path 21 extending in the Y-axis direction and transfer the polymer wafer T between the cassette C on the cassette mounting table 10 and a transition device 30 described later.

[0020] On the positive X-axis side of the wafer transfer device 20, an in / out station 2 is provided with a transition device 30 adjacent to the wafer transfer device 20 for delivering the polymerized wafer T to and from the processing station 3.

[0021] The processing station 3 is equipped with a wafer transfer 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 provided on the positive X-axis side of the transition device 30. The wafer transfer device 40 is configured to be movable on a transfer path 41 extending in the X-axis direction and is configured to be able to transfer the polymerized wafer T to and from the transition device 30, the interface modification device 50, the internal modification device 60, the peripheral removal device 70, and the cleaning device 80 of the in / out station 2.

[0023] The interface modification device 50 irradiates a laser beam (interface laser beam, such as a CO2 laser) on the interface between the first wafer W and the second wafer S to form a bonding force reduction region R where the bonding force between the first wafer W and the second wafer S is reduced.

[0024] As shown in FIGS. 3A and 3B, the interface modification device 50 has a chuck 100 as a holding part for holding the polymerized wafer T on its upper surface. The chuck 100 adsorbs and holds the back surface Sb of the second wafer S in a state where the first wafer W is on the upper side and the second wafer S is on the lower side. The chuck 100 is supported by a slider table 102 via an air bearing 101. A rotation mechanism 103 is provided on the lower surface side of the slider table 102. The rotation mechanism 103 incorporates, for example, a motor as a drive source. The chuck 100 is configured to be rotatable about a vertical axis by the rotation mechanism 103 via the air bearing 101. The slider table 102 is configured to be movable on a rail 106 extending in the Y-axis direction on a base 105 via a moving mechanism 104 provided on its lower surface side. Note that the drive source of the moving mechanism 104 is not particularly limited, and for example, a linear motor is used.

[0025] Above the chuck 100, a laser head 110 as an irradiation unit is provided. The laser head 110 has a lens 111. The lens 111 is a cylindrical member provided on the lower surface of the laser head 110, and irradiates interface laser light onto the inside of the polymerized wafer T held by the chuck 100, more specifically, at the interface between the first wafer W and the second wafer S. As a result, the portion irradiated with the interface laser light inside the polymerized wafer T is modified, and a bonding force reduction region R where the bonding force between the first wafer W and the second wafer S is reduced is formed.

[0026] The laser head 110 is supported by a support member 112. The laser head 110 is configured to be movable up and down by a lifting mechanism 114 along a rail 113 extending in the vertical direction. The laser head 110 is also configured to be movable in the Y-axis direction by a moving mechanism 115. The lifting mechanism 114 and the moving mechanism 115 are each supported by a support column 116.

[0027] Above the chuck 100 and on the positive Y-axis side of the laser head 110, a macro camera 120 and a micro camera 121 are provided. For example, the macro camera 120 and the micro camera 121 are integrally configured, and the macro camera 120 is disposed on the positive Y-axis side of the micro camera 121. The macro camera 120 and the micro camera 121 are configured to be movable up and down by a lifting mechanism 122, and further configured to be movable in the Y-axis direction by a moving mechanism 123.

[0028] The macro camera 120 as an outer end imaging unit images the outer end of the first wafer W (polymerized wafer T). The image captured by the macro camera 120 is used, for example, for the alignment of the first wafer W described later. The macro camera 120 includes, for example, a coaxial lens, irradiates infrared light (IR), and further receives reflected light from the object. For example, the imaging magnification of the macro camera 120 is 2 times.

[0029] The micro camera 121 as the boundary imaging unit images the peripheral part We of the first wafer W and images the boundary Ad between the bonding region Ac and the unbonded region Ae. The image captured by the micro camera 121 is used, for example, to determine the irradiation position of the laser light for the interface described later. The micro camera 121 includes, for example, a coaxial lens, irradiates infrared light (IR light), and further receives the reflected light from the object. For example, the imaging magnification of the micro camera 121 is 10 times, the field of view is about 1 / 5 that of the macro camera 120, and the pixel size is about 1 / 5 that of the macro camera 120.

[0030] In the illustrated example, the macro camera 120 and the micro camera 121 are arranged so that the outer end of the first wafer W and the boundary Ad can be imaged respectively. However, for example, when it is not necessary to perform the alignment described later in the interface modification apparatus 50, one of the macro camera 120 or the micro camera 121 can be omitted. At this time, by configuring to image the boundary Ad with the micro camera 121 having a high imaging magnification, the boundary Ad can be detected with higher accuracy compared to the case of configuring to image the boundary Ad with the macro camera 120.

[0031] Also, in the illustrated example, the chuck 100 is configured to be rotatable and movable horizontally relative to the laser head 110 by the rotation mechanism 103 and the movement mechanism 104. However, the laser head 110 may be configured to be rotatable and movable horizontally relative to the chuck 100. Also, both the chuck 100 and the laser head 110 may be configured to be rotatable and movable horizontally relative to each other.

[0032] The internal modification device 60 irradiates the interior of the first wafer W with a laser beam (an internal laser beam, such as a YAG laser) to form a peripheral modification layer M1 that serves as a basis for peeling the peripheral portion We and a dicing modification layer M2 that serves as a basis for fragmenting the peripheral portion We. The configuration of the internal modification device 60 is not particularly limited. In one example, the internal modification device 60 includes a chuck that holds the polymerized wafer T on the upper surface, a rotation mechanism that relatively rotates the chuck and the polymerized wafer (the first wafer W), a movement mechanism that relatively moves the chuck and the polymerized wafer (the first wafer W) in the horizontal direction, and a laser irradiation unit (laser head) that irradiates the interior of the first wafer W held by the chuck with the internal laser beam.

[0033] The peripheral removal device 70 performs removal of the peripheral portion We of the first wafer W, that is, edge trimming, with the peripheral modification layer M1 formed by the internal modification device 60 as a basis. The method of edge trimming can be arbitrarily selected. In one example, in the peripheral removal device 70, for example, a blade having a wedge shape may be inserted. Also, for example, air blow or water jet may be jetted toward the peripheral portion We to apply an impact to the peripheral portion We.

[0034] The cleaning device 80 performs a cleaning process on the first wafer W and the second wafer S after edge trimming by the peripheral removal device 70 to remove particles on these wafers. The cleaning method can be arbitrarily selected.

[0035] The above wafer processing system 1 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 for controlling the processing of the polymerized wafer T in the wafer processing system 1. Further, the program storage unit also stores a program for controlling the operations of the drive systems of the various processing devices and transfer devices described above to realize the wafer processing described later in the wafer processing system 1. Note that the above program may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control device 90. Also, the above storage medium H may be temporary or non-temporary.

[0036] Next, the wafer processing performed using the wafer processing system 1 configured as described above will be described. In the present embodiment, a first wafer W and a second wafer S are bonded to form a polymerized wafer T in advance.

[0037] First, a cassette C containing a plurality of polymerized wafers T is placed on the cassette mounting table 10 of the loading / unloading station 2.

[0038] Next, the polymerized wafer T in the cassette C is taken out by the wafer transfer device 20 and transferred to the internal modification device 60 via the transition device 30. In the internal modification device 60, as shown in Fig. 4(a), the inside of the first wafer W is irradiated with an internal laser beam L1 to form a peripheral modification layer M1 and a division modification layer M2. The peripheral modification layer M1 serves as a base point when removing the peripheral portion We in the edge trim described later. The division modification layer M2 serves as a base point for fragmenting the small pieces of the peripheral portion We to be removed. In the drawings used in the following description, the illustration of the division modification layer M2 may be omitted in order to avoid complexity in illustration.

[0039] The polymer wafer T, in which the peripheral modification layer M1 and the dicing modification layer M2 are formed inside the first wafer W, is then transported to the interface modification device 50 by the wafer transport device 40. In the interface modification device 50, while rotating the polymer wafer T (the first wafer W) and moving it horizontally along the Y-axis direction, the interface laser beam L2 is pulsed onto the bonding interface between the first wafer W and the second wafer S at the peripheral portion We. Thereby, as shown in FIG. 4(b), the bonding interface between the first wafer W and the second wafer S is modified. In the embodiment, for the modification of the bonding interface, as an example, it is assumed that the amorphization of the bonding film Fw at the irradiation position of the interface laser beam L2, the peeling between the first wafer W and the second wafer S, and the like are included.

[0040] In the interface modification device 50, by modifying the irradiation position of the interface laser beam L2 at the interface between the first wafer W and the second wafer S in this way, a bonding strength reduction region R where the bonding strength between the first wafer W and the second wafer S is reduced is formed. In the edge trim described later, the peripheral portion We of the first wafer W to be removed is removed, but due to the existence of such a bonding strength reduction region R, the removal of such a peripheral portion We can be appropriately performed.

[0041] The detailed formation method of the bonding strength reduction region R in the interface modification device 50 will be described later.

[0042] The polymer wafer T in which the bonding strength reduction region R is formed is then transported to the peripheral removal device 70 by the wafer transport device 40. In the peripheral removal device 70, as shown in FIG. 4(c), the peripheral portion We of the first wafer W is removed, that is, edge trim is performed. At this time, the peripheral portion We is peeled off from the central portion of the first wafer W (radially inside the peripheral portion We) with the peripheral modification layer M1 as a base point, and is completely peeled off from the second wafer S with the bonding strength reduction region R as a base point. Also at this time, the peripheral portion We to be removed is fragmented with the dicing modification layer M2 as a base point.

[0043] When removing the peripheral portion We, for example, a blade B having a wedge shape (see FIG. 4(c)) may be inserted at the interface between the first wafer W and the second wafer S that form the polymer wafer T.

[0044] The polymer wafer T from which the peripheral portion We of the first wafer W has been removed is then conveyed by the wafer transfer device 40 to the cleaning device 80. In the cleaning device 80, the first wafer W and / or the second wafer S after the peripheral portion We has been removed is cleaned.

[0045] In the cleaning device 80, as shown in FIG. 4(d), for example, the cleaning laser light L3 may be irradiated onto the first wafer W and the second wafer S to modify and remove the irradiated portion of the laser light, thereby removing (cleaning) residual particles and the like.

[0046] Thereafter, the polymer wafer T that has undergone all the processes is conveyed by the wafer transfer device 20 to the cassette C on the cassette mounting table 10 via the transition device 30. Thus, a series of wafer processes in the wafer processing system 1 is completed.

[0047] In the above description, as shown in FIGS. 4(a) and 4(b), after the peripheral modification layer M1 and the division modification layer M2 are formed by the internal modification device 60, the bonding force reduction region R is formed by the interface modification device 50. However, the order of the wafer processes in the wafer processing system 1 is not limited to this. That is, after the bonding force reduction region R is formed by the interface modification device 50, the peripheral modification layer M1 and the division modification layer M2 may be formed by the internal modification device 60.

[0048] Next, a detailed method for forming the bonding force reduction region R described above will be described with reference to the drawings.

[0049] As shown in FIG. 1B, an unbonded region Ae is formed at the bonding interface between the first wafer W and the second wafer S in the bonded wafer T, for example, corresponding to the chamfered portion of the first wafer W. In such an unbonded region Ae, since the first wafer W and the second wafer S are not bonded, it is not necessary to form the bonding force reduction region R shown in FIG. 4(b) above. Therefore, in the wafer processing according to the present embodiment, the interface modification apparatus 50 detects the unbonded region Ae and controls so as not to irradiate the detected unbonded region Ae with the interface laser beam L2.

[0050] In the interface modification apparatus 50, first, the bonded wafer T held by the chuck 100 is moved to the macro imaging position. The macro imaging position is a position where the macro camera 120 can image the outer end portion of the first wafer W. At the macro imaging position, while rotating the chuck 100, an image of the outer end portion in the circumferential direction of 360 degrees of the first wafer W is captured by the macro camera 120 (step St1: imaging of the end portion in FIG. 5). The captured image is output from the macro camera 120 to the control device 90.

[0051] The control device 90 calculates the amount of eccentricity between the center of the chuck 100 and the center of the first wafer W from the image of the macro camera 120. Further, in the control device 90, based on the calculated amount of eccentricity, the amount of movement of the chuck 100 is calculated so as to correct the Y-axis component of the amount of eccentricity. The control device 90 moves the chuck 100 horizontally along the Y-axis direction based on the calculated amount of movement, and moves the chuck 100 to the micro imaging position (step St2: alignment in FIG. 5). The micro imaging position is a position where the micro camera 121 can image the unbonded region Ae of the first wafer W. Here, as described above, since the field of view of the micro camera 121 is about 1 / 5 smaller than that of the macro camera 120, if the Y-axis component of the amount of eccentricity is not corrected, the unbonded region Ae may not enter the angular field of view of the micro camera 121 and may not be imaged by the micro camera 121. Therefore, the correction of the Y-axis component based on the calculated amount of eccentricity can be said to be for moving the chuck 100 to the micro imaging position.

[0052] Next, while rotating the chuck 100, the micro camera 121 images the unbonded region Ae in the 360-degree circumferential direction of the first wafer W, and more specifically, the boundary Ad between the bonded region Ac and the unbonded region Ae in the 360-degree circumferential direction of the first wafer W (step St3 in FIG. 5: imaging of the boundary Ad). The captured image is output from the micro camera 121 to the control device 90.

[0053] In the control device 90, an irradiation region of the interface laser light for forming the bonding strength reduction region R is set from the image of the micro camera 121 (step St4 in FIG. 5: determination of the irradiation region).

[0054] As shown as an example in FIG. 6, the boundary Ad between the bonded region Ac and the unbonded region Ae may be formed non-uniformly in the radial direction over 360 degrees in the circumferential direction. Therefore, in the present embodiment, the radial width d1 of the unbonded region Ae (the distance between the boundary Ad and the end of the first wafer W) is calculated over 360 degrees in the circumferential direction of the first wafer W based on the image of the micro camera 121, and the position where the radial width d1 is the smallest (the position where the unbonded region Ae is formed closest to the end of the first wafer W) is set as the reference position P, and an annular region radially inside the reference position P is set as the irradiation region of the interface laser light. At this time, the radial width d2 of the bonded region Ac (the distance between the boundary Ad and the formation position of the peripheral modified layer M1) may be further calculated.

[0055] When the irradiation region of the interface laser light is set, next, the interface laser light L2 is pulsed from the laser head 110 to form a bonding strength reduction region R at the bonding interface between the first wafer W and the second wafer S as shown in FIGS. 4(b) and 7 (step St5 in FIG. 5). Specifically, the frequency of the interface laser light L2 and the rotation speed of the chuck 100 (the superposed wafers T) are controlled so that the laser light is irradiated at the determined pulse pitch Q1, and the moving speed of the chuck 100 (the superposed wafers T) in the Y-axis direction is controlled so that the laser light is irradiated at the determined index pitch Q2.

[0056] Note that the bonding strength reduction region R may be formed from the inner side to the outer side in the radial direction in the annular region which is the irradiation region of the interface laser beam, or may be formed from the outer side to the inner side in the radial direction.

[0057] Thereafter, the polymerized wafer T in which the bonding strength reduction region R is formed is carried out from the interface modification device 50 by the wafer transfer device 40, and a series of processes in the interface modification device 50 are completed.

[0058] According to the present embodiment, at least one of an unbonded region Ae where the first wafer W and the second wafer S are not bonded or a bonding strength reduction region R where the bonding strength is reduced is formed on the entire surface of the peripheral edge portion We to be removed. That is, due to the unbonded region Ae or the bonding strength reduction region R, the bonding strength between the first wafer W and the second wafer S is at least reduced over the entire surface of the peripheral edge portion We, so that the peripheral edge portion We is appropriately removed from the second wafer S.

[0059] Further, according to the present embodiment, the formation region of the bonding strength reduction region R (the irradiation region of the interface laser beam L2) is determined to be an annular region radially inside the position (reference position P) where the radial width d1 of the unbonded region Ae obtained by imaging in step St3 is the smallest.

[0060] Here, when the detection of the unbonded region Ae (more specifically, the boundary Ad) by the micro camera 121 is not performed to determine the formation region of the bonding strength reduction region R, in order to reduce the bonding strength between the first wafer W and the second wafer S over the entire surface of the peripheral portion We, it is necessary to start irradiating the interface laser beam L2 from the outer peripheral end of the first wafer W and form the bonding strength reduction region R over the entire surface of the peripheral portion We. In this regard, according to the above method according to the technology of the present disclosure, by detecting the unbonded region Ae (boundary Ad) by the micro camera 121 and setting the reference position P, as shown in FIG. 7, the bonding strength reduction region R can be appropriately formed inside the reference position P in the radial direction in the peripheral portion We, and the unbonded region Ae is formed over the entire surface outside the reference position P in the radial direction. Therefore, without irradiating the entire surface of the peripheral portion We to be removed with the laser beam, the bonding strength can be reduced at least over the entire surface of the peripheral portion We to be removed. As a result, the peripheral portion We can be appropriately peeled off from the polymerized wafer T, and it is possible to shorten the processing time required for forming the bonding strength reduction region R and reduce the energy consumption for irradiating the laser beam during the formation.

[0061] Furthermore, according to the present embodiment, by determining the formation region of the bonding strength reduction region R as an annular region inside the reference position P in the radial direction as described above, the interface laser beam L2 is not irradiated to the unbonded region Ae outside the reference position P in the radial direction in the peripheral portion We. In other words, at least the irradiation of the interface laser beam L2 to the unbonded region Ae where it is not necessary to reduce the bonding strength is omitted, and the formation region (processing width) of the bonding strength reduction region R is made smaller compared to the conventional case. As a result, the number of irradiations of the interface laser beam L2 to the bonding interface between the first wafer W and the second wafer S can be reduced, the productivity (throughput) related to the formation of the bonding strength reduction region R can be appropriately improved, and the amount of energy consumption related to the formation of the bonding strength reduction region R can be reduced.

[0062] Also, by reducing the number of irradiations of the interface laser beam L2 to the interface between the first wafer W and the second wafer S in this way, the amount of debris / particles generated during the formation of the bonding strength reduction region R can be appropriately reduced. Furthermore, since the amount of debris / particles generated in this way can be reduced, when performing cleaning with the cleaning device 80, the amount of energy consumed and the amount of cleaning liquid can be reduced, and the productivity related to the cleaning can be improved.

[0063] In addition, if the interface laser beam L2 can be irradiated onto the entire irradiated area determined in step St4, the irradiation method of the interface laser beam L2 on the peripheral portion We can be arbitrarily determined. For example, while rotating the polymerization wafer T and moving the laser head 110 horizontally along the Y-axis direction, the interface laser beam L2 is irradiated in a pulsed manner. As shown in FIG. 8A, the irradiation positions of the interface laser beam L2 on the irradiated area may be arranged in a spiral shape in a plan view. Also, for example, by repeating the operation of moving the irradiation position of the interface laser beam L2 in the radial direction after rotating the polymerization wafer T once, as shown in FIG. 8B, the irradiation positions of the interface laser beam L2 on the irradiated area may be arranged concentrically with respect to the first wafer W in a plan view.

[0064] As shown in FIG. 8A, when the irradiation positions of the interface laser beam L2 are arranged in a spiral shape, the number of movements of the chuck 100 (polymerization wafer T) in the Y-axis direction can be reduced, and the productivity (throughput) related to the formation of the bonding strength reduction region R can be improved. In addition, as shown in FIG. 8B, when the irradiation positions of the interface laser beam L2 are arranged concentrically, it becomes easy to control the irradiation positions of the interface laser beam L2, and the processing width of the bonding strength reduction region R can be appropriately controlled to improve the processing quality related to edge trimming.

[0065] Here, in order to appropriately remove the peripheral portion We of the first wafer W to be removed, it is necessary to irradiate the entire irradiated area (the entire bonding area Ac in the peripheral portion We) determined in step St3 with the interface laser beam L2. In particular, in order to appropriately set the removal width of the peripheral portion We, it is necessary to form the bonding strength reduction region R along the entire circumference along the peripheral modification layer M1 formed inside the first wafer W.

[0066] Therefore, in the present embodiment, as shown in FIG. 9A, at least at the radially inner (peripheral modification layer M1 side) end portion in the irradiation region of the interface laser beam L2, it is desirable to arrange the irradiation region of the interface laser beam L2 concentrically with respect to the first wafer W (see the first region R1 in FIG. 9A). By forming the concentric first region R1 along the peripheral modification layer M1 in this way, the peripheral portion We can be appropriately removed with a desired removal width. Also at this time, in a region that has nothing to do with the accuracy of the processing width on the radially outer side of the concentric first region R1, in order to improve the productivity related to the formation of the bonding strength reduction region R, it is desirable to arrange the irradiation region of the interface laser beam L2 in a spiral shape (see the second region R2 in FIG. 9A).

[0067] Note that the concentric first region R1 and the spiral second region R2 may be formed such that at least a part thereof overlaps in a plan view as shown in FIG. 9B. In this way, by forming the first region R1 and the second region R2 to overlap, the bonding strength reduction region R is appropriately formed over the entire surface of the irradiation region of the interface laser beam L2, and the peripheral portion We can be appropriately peeled off from the bonded wafer T (the first wafer W).

[0068] Note that from the viewpoint of appropriately removing the peripheral portion We of the first wafer W to be removed, it is desirable to form the bonding strength reduction region R so as to overlap at least the boundary Ad between the bonding region Ac and the unbonded region Ae over the entire circumference in a plan view. In such a case, for example, at least at the radially outer (end portion side of the first wafer W) end portion in the irradiation region of the interface laser beam L2, the irradiation region of the interface laser beam L2 may be arranged concentrically with respect to the first wafer W starting from the reference position P. Also, for example, when the bonding strength reduction region R is formed in a spiral shape, it is desirable to overlap at least the unbonded region Ae with the irradiation start position (or end position) of the interface laser beam L2 for forming the bonding strength reduction region R.

[0069] In the above embodiment, as shown in FIG. 7, the entire annular region radially inside the reference position P obtained from the image of the micro camera 121 was irradiated with the interface laser light L2 to form the bonding force reduction region R. However, the method for forming the bonding force reduction region R is not limited to this.

[0070] Specifically, as shown in FIG. 10, along Ad at the boundary between the bonded region Ac and the unbonded region Ae obtained from the image of the micro camera 121, the formation width of the bonding force reduction region R in the circumferential direction of 360 degrees of the first wafer W may be determined. In other words, based on the radial width d2 of the bonded region Ac shown in FIG. 6, the irradiation region of the interface laser light L2 is determined. Even in a region radially inside the reference position P, for the unbonded region Ae where the first wafer W and the second wafer S are not bonded, the irradiation of the interface laser light L2 may be omitted. Thereby, the amount of energy consumption related to the formation of the bonding force reduction region R can be further reduced, and the amount of debris / particles generated can be further reduced.

[0071] In the above embodiment, as shown in FIG. 4(b), the bonding force reduction region R was formed at the bonding interface between the first wafer W and the second wafer S (the interface between the bonding film Fw and the bonding film Fs). However, the formation position of the bonding force reduction region R is not limited to this as long as the peripheral portion We of the first wafer W can be appropriately removed.

[0072] Specifically, as shown in FIG. 11A, for example, the interface laser light L2 may be irradiated on the interface between the device layer Dw formed on the surface Wa of the first wafer W and the first wafer W to form the bonding force reduction region R. In such a case, in the peripheral removal device 70, by applying an impact to the peripheral portion We, a crack is generated from the radially outer end portion of the bonding force reduction region R toward the bonding interface between the first wafer W and the second wafer S, and as shown in FIG. 11(b), the peripheral portion We is removed with the bonding force reduction region R as a base point.

[0073] Specifically, for example, the interface laser beam L2 may be irradiated inside the device layer Dw formed on the surface Wa of the first wafer W to form the bonding strength reduction region R. Even in such a case, in the peripheral removal device 70, by applying an impact to the peripheral portion We, a crack is generated from the radially outer end portion of the bonding strength reduction region R toward the bonding interface between the first wafer W and the second wafer S, and the peripheral portion We is removed.

[0074] In the above embodiment, as shown in FIG. 6, the position of the reference position P where the radial width d1 of the unbonded region Ae is the smallest is detected by the micro camera 121 of the interface modification device 50, but the position where the radial width d1 of the unbonded region Ae is the largest may be further detected.

[0075] Here, for example, when the unbonded region Ae is formed radially inside the peripheral modification layer M1 due to a bonding defect of the polymerized wafer T or the like, there is a possibility that the first wafer W may float with respect to the second wafer S after the peripheral portion We is removed. Therefore, in the present embodiment, when the position where the radial width d1 of the unbonded region Ae is the largest is detected in this way and the detected position is radially inside the formation position of the peripheral modification layer M1, a warning may be issued to the operator. In such a case, the polymerized wafer T for which such a warning has been issued may have the wafer processing immediately stopped, or the detected position may be reset as the radially inner end portion of the peripheral portion We (the formation position of the peripheral modification layer M1) that serves as the basis for removing the peripheral portion We.

[0076] In the above embodiment, as shown in FIG. 5, the eccentricity correction of the polymerized wafer T and the chuck 100 (step St2) and the irradiation of the interface laser beam L2 (step St5) are performed independently, but these eccentricity correction and the irradiation of the interface laser beam L2 may be performed simultaneously. That is, while rotating the chuck 100 and irradiating the interface laser beam L2, the chuck 100 and the laser head 110 may be relatively moved horizontally along the Y-axis direction. Similarly, in the above embodiment, as shown in FIG. 5, the eccentricity correction of the polymerization wafer T and the chuck 100 (step St2) and the imaging of the boundary Ad (step St3) were performed independently. However, these eccentricity correction and the imaging of the boundary Ad may be performed simultaneously. That is, while imaging the boundary Ad in the circumferential direction of 360 degrees while rotating the chuck 100, the chuck 100 and the laser head 110 may be relatively horizontally moved along the Y-axis direction.

[0077] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The above embodiments may be omitted, replaced, or changed in various forms without departing from the scope and gist of the appended claims.

Explanation of Reference Numerals

[0078] 1 Wafer processing system 50 Interface modification device 60 Internal modification device 70 Peripheral removal device 90 Control device 110 Laser head 121 Micro camera Ac Bonding region Ad Boundary Ae Unbonded region L2 Laser light for interface M1 Peripheral modification layer P Reference position R Region with reduced bonding force S Second wafer T Polymerization wafer W First wafer We Peripheral part

Claims

1. A method for processing a polymerized substrate in which a first substrate and a second substrate are joined, wherein the peripheral portion of the first substrate to be removed has a joined region joined to the second substrate and an unjoined region not joined to the second substrate on the radially outer side of the joined region, forming a peripheral modification layer serving as a base point for peeling of the peripheral portion along the boundary between the peripheral portion of the first substrate and the central portion of the first substrate; detecting the boundary position between the joined region and the unjoined region over the entire circumference of the first substrate; irradiating a laser beam on the joined region side with respect to the detected boundary position to form a joining force reduction region for reducing the joining force between the first substrate and the second substrate; peeling the peripheral portion from the polymerized substrate with the peripheral modification layer as a base point; including determining, as a reference position, the boundary position closest to the outer peripheral end of the first substrate among the boundary positions detected over the entire circumference, In the formation of the joining force reduction region, the laser beam is irradiated on an annular region on the joined region side with respect to the reference position. A processing method.

2. A method for processing a polymerized substrate in which a first substrate and a second substrate are joined, wherein the peripheral portion of the first substrate to be removed has a joined region joined to the second substrate and an unjoined region not joined to the second substrate on the radially outer side of the joined region, forming a peripheral modification layer serving as a base point for peeling of the peripheral portion along the boundary between the peripheral portion of the first substrate and the central portion of the first substrate; detecting the boundary position between the joined region and the unjoined region over the entire circumference of the first substrate; irradiating a laser beam on the joined region side with respect to the detected boundary position to form a joining force reduction region for reducing the joining force between the first substrate and the second substrate; peeling the peripheral portion from the polymerized substrate with the peripheral modification layer as a base point; In the formation of the joining force reduction region, the laser beam is irradiated along the boundary position, and the joining force reduction region is formed only in the joined region radially inward of the boundary position detected over the entire circumference. A processing method.

3. A method for processing a polymerized substrate in which a first substrate and a second substrate are joined, wherein the peripheral portion of the first substrate to be removed has a joined region joined to the second substrate and an unjoined region not joined to the second substrate on the radially outer side of the joined region, Forming a peripheral modification layer serving as a base point for peeling of the peripheral portion along a boundary between the peripheral portion and the central portion of the first substrate; Detecting a boundary position between the bonded region and the unbonded region over the entire circumference of the first substrate; Irradiating a laser beam on the bonded region side of the detected boundary position to form a bonding force reduction region for reducing the bonding force between the first substrate and the second substrate; Peeling the peripheral portion from the polymerized substrate with the peripheral modification layer as a base point; Detecting an outer peripheral end portion position of the first substrate over the entire circumference of the first substrate; Calculating an amount of eccentricity between the center of the first substrate and the center of a holding portion that holds the polymerized substrate based on the detected outer peripheral end portion position, and The detection of the boundary position is performed while correcting the amount of eccentricity by relatively moving the holding portion and an irradiation portion that irradiates the laser beam in a horizontal direction, or after correcting the amount of eccentricity, a processing method.

4. A method for processing a polymerized substrate in which a first substrate and a second substrate are bonded, The peripheral portion of the first substrate to be removed, A bonded region bonded to the second substrate, In the radially outer side of the bonded region, it has an unbonded region not bonded to the second substrate, and Forming a peripheral modification layer serving as a base point for peeling of the peripheral portion along a boundary between the peripheral portion and the central portion of the first substrate; Detecting a boundary position between the bonded region and the unbonded region over the entire circumference of the first substrate; Irradiating a laser beam on the bonded region side of the detected boundary position to form a bonding force reduction region for reducing the bonding force between the first substrate and the second substrate; Peeling the peripheral portion from the polymerized substrate with the peripheral modification layer as a base point; Detecting an outer peripheral end portion position of the first substrate over the entire circumference of the first substrate; Calculating an amount of eccentricity between the center of the first substrate and the center of a holding portion that holds the polymerized substrate based on the detected outer peripheral end portion position, and The formation of the bonding force reduction region is performed while correcting the amount of eccentricity by relatively moving the holding portion and an irradiation portion that irradiates the laser beam in a horizontal direction, a processing method.

5. The processing method according to any one of claims 1 to 4, wherein the bonding force reduction region is formed at a bonding interface between the first substrate and the second substrate.

6. A device layer is formed on the surface of the first substrate, The processing method according to any one of claims 1 to 4, wherein the bonding force reduction region is formed at an interface between a surface of the first substrate and the device layer or inside the device layer.

7. A processing system for processing a polymerized substrate in which a first substrate and a second substrate are bonded, The peripheral edge of the first substrate to be removed, A bonding region bonded to the second substrate, On the radially outer side of the bonding region, there is an unbonded region not bonded to the second substrate, The processing system, An internal modification device for forming a peripheral modification layer serving as a base point for peeling the peripheral edge of the first substrate, An interface modification device for forming a bonding force reduction region for reducing the bonding force between the first substrate and the second substrate, A peripheral removal device for peeling the peripheral edge from the polymerized substrate, A control device, The interface modification device, A boundary imaging unit for detecting a boundary position between the bonding region and the unbonded region over the entire circumference of the first substrate, An irradiation unit for irradiating laser light for forming the bonding force reduction region, The control device, Performs control to irradiate the laser light on the bonding region side of the boundary position detected by the boundary imaging unit to form the bonding force reduction region. Furthermore, the control device, Performs control to determine, as a reference position, the boundary position closest to the outer peripheral end of the first substrate among the boundary positions detected over the entire circumference. A processing system that performs control to operate the interface modification device so as to irradiate the laser light on an annular region on the bonding region side of the reference position in the formation of the bonding force reduction region.

8. A processing system for processing a polymerized substrate in which a first substrate and a second substrate are bonded, The peripheral edge of the first substrate to be removed, A bonding region bonded to the second substrate, On the radially outer side of the bonding region, there is an unbonded region not bonded to the second substrate, The processing system, An internal modification device for forming a peripheral modification layer serving as a base point for peeling the peripheral edge of the first substrate, An interface modification device for forming a bonding force reduction region for reducing the bonding force between the first substrate and the second substrate, A peripheral removal device for peeling the peripheral edge from the polymerized substrate, A control device, The interface modification device, A boundary imaging unit for detecting a boundary position between the bonding region and the unbonded region over the entire circumference of the first substrate, An irradiation unit for irradiating laser light for forming the bonding force reduction region, The control device, Performing control to form the bonding force reduction region by irradiating the laser light on the bonding region side with respect to the boundary position detected by the boundary imaging unit. Furthermore, the control device In the formation of the bonding force reduction region, performing control to operate the interface modification device so as to irradiate the laser light along the boundary position and form the bonding force reduction region only in the bonding region radially inside the boundary position detected over the entire circumference.

9. A processing system for processing a polymerized substrate in which a first substrate and a second substrate are bonded, The peripheral portion of the first substrate to be removed Has a bonding region bonded to the second substrate, And an unbonded region that is not bonded to the second substrate on the radially outer side of the bonding region. The processing system An internal modification device for forming a peripheral modification layer that serves as a base point for peeling the peripheral portion of the first substrate, An interface modification device for forming a bonding force reduction region that reduces the bonding force between the first substrate and the second substrate, A peripheral removal device for peeling the peripheral portion from the polymerized substrate, And a control device. The interface modification device Has a boundary imaging unit that detects the boundary position between the bonding region and the unbonded region over the entire circumference of the first substrate, And an irradiation unit that irradiates laser light for forming the bonding force reduction region. The control device Performs control to form the bonding force reduction region by irradiating the laser light on the bonding region side with respect to the boundary position detected by the boundary imaging unit. The interface modification device Has an outer end imaging unit that detects the outer peripheral end position of the first substrate over the entire circumference of the first substrate, And a moving mechanism that relatively moves the polymerized substrate and the irradiation unit in the horizontal direction. Furthermore, the control device Performs control to calculate the amount of eccentricity between the center of the first substrate and the center of the holding unit that holds the polymerized substrate based on the detected outer peripheral end position. Performs control to relatively move the polymerized substrate and the irradiation unit in the horizontal direction to correct the amount of eccentricity. Performs control to operate the interface modification device so as to correct the amount of eccentricity by relatively moving the holding unit and the irradiation unit in the horizontal direction, or after correcting the amount of eccentricity, detect the boundary position.

10. A processing system for processing a polymerized substrate in which a first substrate and a second substrate are bonded, The peripheral portion of the first substrate to be removed a bonding region bonded to the second substrate, and an unbonded region that is not bonded to the second substrate on the radially outer side of the bonding region. The processing system includes an internal modification device that forms a peripheral modification layer serving as a base point for peeling of the peripheral portion of the first substrate, an interface modification device that forms a bonding force reduction region for reducing the bonding force between the first substrate and the second substrate, a peripheral removal device that peels the peripheral portion from the polymerized substrate, and a control device. The interface modification device includes a boundary imaging unit that detects a boundary position between the bonding region and the unbonded region over the entire circumference of the first substrate, and an irradiation unit that irradiates laser light for forming the bonding force reduction region. The control device performs control to form the bonding force reduction region by irradiating the laser light on the bonding region side with respect to the boundary position detected by the boundary imaging unit. The interface modification device further includes an outer end imaging unit that detects an outer peripheral end position of the first substrate over the entire circumference of the first substrate, and a moving mechanism that relatively moves the polymerized substrate and the irradiation unit in a horizontal direction. Furthermore, the control device performs control to calculate an eccentricity amount between the center of the first substrate and the center of a holding unit that holds the polymerized substrate based on the detected outer peripheral end position, performs control to relatively move the polymerized substrate and the irradiation unit in a horizontal direction to correct the eccentricity amount, and performs control to operate the interface modification device so as to form the bonding force reduction region while correcting the eccentricity amount by relatively moving the holding unit and the irradiation unit in a horizontal direction.

11. The processing system according to any one of claims 7 to 10, wherein the control device performs control to form the bonding force reduction region at a bonding interface between the first substrate and the second substrate.

12. A device layer is formed on the surface of the first substrate, and the processing system according to any one of claims 7 to 10, wherein the control device performs control to form the bonding force reduction region at an interface between the surface of the first substrate and the device layer or inside the device layer.

Images