JP2021190436A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

To properly peel off a first substrate from a second substrate in a polymerized substrate where the first substrate and the second substrate are bonded.SOLUTION: In a method for processing a polymerized substrate to which a first substrate and a second substrate, on which a surface film is formed in layers, are bonded, the surface film includes an absorption layer of laser light, and the laser light inhibiting film formed on the back surface of the first substrate is removed by blasting, and the absorption layer is irradiated with laser light from the back side of the first substrate, and the first substrate is peeled off from the second substrate.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a substrate processing method and a substrate processing apparatus.

Patent Document 1 discloses a method for grinding a wafer. Such a wafer grinding method includes a step of irradiating a laser beam along the outer peripheral edge at a position inside a predetermined amount from one surface side of the wafer to remove the outer peripheral portion of the wafer and removing the outer peripheral portion. It includes a step of grinding a surface to be ground of a wafer to form a predetermined finished thickness.

Japanese Unexamined Patent Publication No. 2006-108532

The technique according to the present disclosure appropriately peels the first substrate from the second substrate in the polymerized substrate in which the first substrate and the second substrate are bonded.

One aspect of the present disclosure is a method for treating a polymerized substrate in which a first substrate formed by laminating surface films and a second substrate are bonded, and the surface film is a laser light absorbing layer. The absorption layer is irradiated with laser light from the back surface side of the first substrate, and the absorption layer is irradiated with laser light from the back surface side of the first substrate. It includes peeling the first substrate from the second substrate.

According to the present disclosure, in a polymerized substrate in which a first substrate and a second substrate are bonded, the first substrate can be appropriately peeled from the second substrate.

It is a side view which shows the structural example of the polymerized wafer processed by the wafer processing system. It is a top view which shows the structure of the wafer processing system which concerns on this Embodiment. It is a vertical sectional view which shows the structure of the blast processing apparatus which concerns on this embodiment. It is explanatory drawing which shows the main process of the wafer processing which concerns on this Embodiment. It is a flow diagram which shows the main process of the wafer processing which concerns on this Embodiment. It is explanatory drawing which shows an example of the removal operation of an inhibitory film in a blast processing apparatus. It is explanatory drawing which shows the example of removal of the inhibitory film by a blast processing apparatus. It is a top view which shows the example of the formation of the reforming layer on the 1st wafer. It is explanatory drawing which shows the state of the exposed surface by removing the peripheral part. It is explanatory drawing which shows the state of removal of a surface film by a blast treatment. It is a vertical sectional view which shows the structure of the blast processing apparatus which concerns on other embodiment. It is a vertical sectional view which shows the structure of the blast processing apparatus which concerns on other embodiment. It is a top view which shows the structure of the wafer processing system which concerns on other embodiment. It is the explanation which shows the other application example of the technology which concerns on this disclosure content. It is the explanation which shows the other application example of the technology which concerns on this disclosure content.

In recent years, in the manufacturing process of a semiconductor device, the polymer wafer is formed by bonding semiconductor substrates (hereinafter referred to as "wafers") having a plurality of devices such as electronic circuits formed on the surface thereof. The wafer of No. 1 is thinned.

Here, normally, the peripheral portion of the wafer is chamfered, but when the thinning treatment is performed on the polymerized wafer as described above, the peripheral portion of the first wafer after thinning has a sharply pointed shape ( It may have a so-called knife edge shape). Then, chipping occurs at the peripheral edge of the first wafer, and the wafer may be damaged. Therefore, before performing the thinning treatment, it is necessary to perform a treatment for suppressing the formation of the knife edge shape on the peripheral portion of the wafer in advance.

The above-mentioned Patent Document 1 describes that, as an example of a method of suppressing the formation of a knife edge shape on a wafer by the thinning treatment, removal of the peripheral edge portion of the wafer before the thinning treatment, so-called edge trimming, is performed. Has been done. Specifically, by irradiating the wafer with a pulsed laser beam, an annular processing groove deeper than the finished thickness of the wafer is formed from the surface on the peripheral edge portion of the wafer, and the peripheral edge portion is removed.

By the way, on the incident surface of the laser beam on the wafer, for example, when an oxide film is naturally formed due to contact with the atmosphere, or an oxide film or nitride film for improving the warp resistance and etching resistance of the wafer is intentionally formed. May form. When an oxide film or a nitride film is formed on the incident surface of the laser beam in this way, these oxide films and nitride films have the property of absorbing and reflecting the irradiated laser light, and thus are described in Patent Document 1. In the above method, it may not be possible to irradiate the desired position of the wafer with the laser beam, and it may not be possible to properly perform edge trimming. Therefore, there is room for improvement in the conventional edge trimming method.

The technique according to the present disclosure appropriately peels the first substrate from the second substrate in the polymerized substrate in which the first substrate and the second substrate are bonded. Hereinafter, the wafer processing system as the substrate processing apparatus and the wafer processing method as the substrate processing method according to the present embodiment will be described with reference to the drawings. In the present specification and the drawings, the elements having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

In the wafer processing system 1 described later according to the present embodiment, as shown in FIG. 1, as a polymerization substrate in which the first wafer W1 as the first substrate and the second wafer W2 as the second substrate are bonded. Processing is performed on the polymerized wafer T of. Then, in the wafer processing system 1, the peripheral edge portion We of the first wafer W1 is peeled off from the second wafer W2 and removed. Hereinafter, in the first wafer W1, the surface on the side to be joined to the second wafer W2 is referred to as a front surface W1a, and the surface opposite to the front surface W1a is referred to as a back surface W1b. Similarly, in the second wafer W2, the surface on the side bonded to the first wafer W1 is referred to as the front surface W2a, and the surface on the side opposite to the front surface W2a is referred to as the back surface W2b. Further, in the following description, the peeling and removal of the peripheral portion We may be collectively referred to as "peeling".

The first wafer W1 is a semiconductor wafer such as a silicon substrate, and a device layer D1 including a plurality of devices is formed on the surface W1a. Further, a bonding film F1 is further formed on the device layer D1 and bonded to the second wafer W2 via the bonding film F1. Examples of the bonding film F1 include an oxide film (SiO ₂ film, TEOS film), a SiC film, a SiCN film, and an adhesive. The peripheral edge portion We of the first wafer W1 is chamfered, and the cross section of the peripheral edge portion We becomes thinner toward the tip thereof. Further, the peripheral edge portion We is a portion 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 W1. At the interface between the first wafer W1 and the device layer D1, an absorption layer (not shown) that absorbs the laser beam irradiated to the inside of the polymerized wafer T when the peripheral edge portion We is removed is further formed. May be good. Further, the bonding film F1 formed on the device layer D1 may be used as the absorption layer.

Further, on the back surface W1b of the first wafer W1, an inhibitory film Ox that absorbs and reflects the laser light emitted to the inside of the polymerized wafer T and inhibits the laser light from reaching the above-mentioned absorption layer is formed. Has been done. As described above, the inhibitory film Ox is intentionally formed, for example, an oxide film (for example, a SiO ₂ film) naturally formed by contact with the atmosphere, or to improve the warp resistance and etching resistance of the wafer. oxide film (e.g., SiO ₂ film) or a nitride film (e.g. _{the Si} 3 _{N 4} film) and the like. Further, as shown in FIG. 1, the bonding film F1 formed on the front surface W1a side of the first wafer W1 may be formed so as to wrap around to the back surface W1b side, thereby acting as an inhibitory film Ox.

The second wafer W2 has, for example, the same configuration as the first wafer W1, a device layer D2 and a bonding film F2 are formed on the surface W2a, and the peripheral edge portion is chamfered. The second wafer W2 does not have to be a device wafer on which the device layer D2 is formed, and may be, for example, a support wafer that supports the first wafer W1. In such a case, the second wafer W2 functions as a protective material for protecting the device layer D1 of the first wafer W1.

In the present embodiment, the device layers D1 and D2 formed on the first wafer W1 and the second wafer W2, the bonding films F1 and F2, and the laser light absorbing layer (not shown) are each "surface film". May be called. In other words, a plurality of surface films are laminated and formed on the first wafer W1 and the second wafer W2 according to the present embodiment.

As shown in FIG. 2, the wafer processing system 1 has a configuration in which a loading / unloading block G1, a transport block G2, and a processing block G3 are integrally connected. The carry-in / out block G1, the transport block G2, and the processing block G3 are arranged side by side in this order from the negative direction side of the X-axis.

The carry-in / out block G1 is provided with a cassette mounting table 10, and for example, a cassette C capable of accommodating a plurality of polymerized wafers T with the outside is carried in / out. In the illustrated example, a plurality of, for example, three cassettes C can be freely placed in a row on the cassette mounting table 10 in the Y-axis direction. The number of cassettes C mounted on the cassette mounting table 10 is not limited to this embodiment and can be arbitrarily determined.

The transfer block G2 is provided with a wafer transfer device 20 adjacent to the cassette mounting table 10 on the X-axis positive direction side of the cassette mounting table 10. The wafer transfer device 20 is configured to be movable on a transfer path 21 extending in the Y-axis direction. Further, the wafer transfer device 20 has, for example, two transfer arms 22 and 22 that hold and transfer the polymerized wafer T. Each transport arm 22 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. The configuration of the transfer arm 22 is not limited to this embodiment, and any configuration may be adopted. The wafer transfer device 20 is configured to be able to transfer the polymerized wafer T to the cassette C of the cassette mounting table 10 and the transition device 30 described later.

Further, the transfer block G2 has a transition for transferring the laminated wafer T to and from the wafer transfer device 40 of the processing block G3 adjacent to the wafer transfer device 20 on the X-axis positive direction side of the wafer transfer device 20. The device 30 is provided.

The processing block G3 includes a wafer transfer device 40, a peripheral edge removing device 50 as a peeling section, a blast processing device 60 as a blast processing section, an interface reforming device 70 as a laser irradiation section, and an internal reforming device as a laser irradiation section. Has 80.

The wafer transfer device 40 is configured to be movable on a transfer path 41 extending in the X-axis direction. Further, the wafer transfer device 40 has, for example, two transfer arms 42 and 42 that hold and transfer the polymerized wafer T. Each transport arm 42 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. The configuration of the transfer arm 42 is not limited to this embodiment, and any configuration may be adopted. The wafer transfer device 40 is configured to be able to transfer the polymerized wafer T to the transition device 30, the peripheral edge removing device 50, the blast processing device 60, the interface reforming device 70, and the internal reforming device 80.

The peripheral edge removing device 50 removes the peripheral edge portion We of the first wafer W1, that is, performs edge trimming processing. The blast processing apparatus 60 blasts the back surface W1b of the first wafer W1 to remove the inhibitory film Ox. The interface reformer 70 irradiates the interface between the first wafer W1 and the second wafer W2 with a laser beam (a laser beam for an interface, for example, a CO ₂ laser) to form an unbonded region Ae described later. The internal reformer 80 irradiates the inside of the first wafer W1 with a laser beam (internal laser beam, for example, a YAG laser), and the peripheral reforming layer M1 serving as a base point for peeling the peripheral edge We, and the peripheral edge We. A split reformed layer M2 is formed as a base point for fragmentation. The detailed configuration of the blast processing device 60 will be described later.

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. Further, the program storage unit also stores a program for controlling the operation of the drive system of the above-mentioned various processing devices and transfer devices to realize the wafer processing described later in the wafer processing system 1. The program may be recorded on a storage medium H readable by a computer and may be installed on the control device 90 from the storage medium H.

The wafer processing system 1 according to the present embodiment is configured as described above. Next, the above-mentioned blast processing apparatus 60 will be described.

As shown in FIG. 3, the blast processing apparatus 60 has a chuck 61 for holding the polymerized wafer T on the upper surface. The chuck 61 holds the back surface W2b of the second wafer W2 in a state where the first wafer W1 is arranged on the upper side and the second wafer W2 is arranged on the lower side. Further, the chuck 61 is configured to be rotatable around a vertical axis by a rotation mechanism (not shown), whereby the polymerized wafer T held on the chuck 61 is configured to be rotatable.

A blast nozzle 62, a cleaning liquid nozzle 63, and a gas nozzle 64 are provided above the chuck 61. The blast nozzle 62, the cleaning liquid nozzle 63, and the gas nozzle 64 are configured to be movable in the horizontal direction above the polymerized wafer T, whereby the entire surface of the back surface W1b of the first wafer W1 can be blasted. Has been done. The blast nozzle 62, the cleaning liquid nozzle 63, and the gas nozzle 64 may be configured to be integrally movable in the horizontal direction, or may be configured to be independently movable.

The blast nozzle 62 injects a slurry (a mixed solution of an abrasive and a liquid) onto the back surface W1b of the first wafer W1 to remove the inhibitory film Ox formed on the back surface W1b of the first wafer W1 (wet blasting). Process). The blast nozzle 62 is connected to a slurry supply unit 62a for supplying the slurry to the blast nozzle 62 and a gas supply source 62b for injecting the slurry from the blast nozzle 62.

As the blast nozzle 62, any nozzle such as a tube nozzle or a slit nozzle can be selected, but it is preferable to select a nozzle having a narrow slurry injection hole (for example, about 10 mm).

The cleaning liquid nozzle 63 supplies the cleaning liquid to the back surface W1b of the first wafer W1, thereby removing the slurry (abrasive material) ejected from the blast nozzle 62 from the back surface W1b. A cleaning liquid supply unit 63a for supplying the cleaning liquid to the cleaning liquid nozzle 63 is connected to the cleaning liquid nozzle 63.

The gas nozzle 64 supplies gas to the back surface W1b of the first wafer W1 and thereby removes the liquid (slurry and cleaning liquid) supplied to the back surface W1b of the first wafer W1. A gas supply source 64a for supplying gas to the gas nozzle 64 is connected to the gas nozzle 64.

Further, around the chuck 61, a cup body 65 for receiving and discharging the slurry and the cleaning liquid scattered from the polymerized wafer T during the blasting process is provided so as to surround the chuck 61. A drainage portion 66 is provided at the lower part of the cup body 65, and the recovered slurry and cleaning liquid, and the inhibitory membrane Ox removed by the blast treatment are discharged to the drainage line.

Further, the blast processing apparatus 60 is provided with an inspection mechanism 67 for inspecting the back surface W1b of the first wafer W1. The inspection mechanism 67 inspects the state of the back surface W1b of the first wafer W1 to which the blasting treatment is performed, and inspects whether or not the inhibitory film Ox is appropriately removed by the blasting treatment. The configuration of the inspection mechanism 67 is not particularly limited and may be any configuration. For example, the removal of the inhibitory film Ox is inspected using an imaging mechanism (CCD camera or the like) or a laser displacement meter. May be good. Further, for example, when the imaging mechanism is used as the inspection mechanism 67, is the inhibitory film Ox removed by detecting the difference in color between the inhibitory film Ox and the first wafer W1 by imaging the first wafer W1? You may decide whether or not.

The blast processing device 60 according to the present embodiment is configured as described above, but the configuration of the blast processing device 60 is not limited to this.

For example, the blast processing apparatus 60 may be further provided with a cleaning liquid nozzle (not shown) for supplying the cleaning liquid to the back surface W2b of the second wafer W2. In such a case, instead of holding the polymerized wafer T from below by the chuck 61, the end portion of the polymerized wafer T may be held by a holding mechanism (not shown). Even in such a case, it is preferable that the polymerized wafer T is rotatably held around the vertical axis in order to appropriately perform the blasting treatment on the entire surface of the back surface W1b of the first wafer W1.

For example, in the above embodiment, the blast nozzle 62, the cleaning liquid nozzle 63, and the gas nozzle 64 are provided above the chuck 61, but either the cleaning liquid nozzle 63 or the gas nozzle 64 may be omitted. Further, in the above embodiment, by providing the blast nozzle 62, the cleaning liquid nozzle 63, and the gas nozzle 64 above the chuck 61 in this way, the blast processing apparatus 60 cleans the first wafer W1 after the blast processing. Although it is configured, the cleaning liquid nozzle 63 and the gas nozzle 64 may be omitted, and a cleaning device (not shown) may be provided independently outside the blast processing device 60.

Next, the wafer processing performed by using the wafer processing system 1 configured as described above and the blast processing apparatus 60 will be described. In this embodiment, a case where the peripheral edge portion We of the first wafer W1 is peeled from the second wafer W2 (so-called edge trim processing) in the wafer processing system 1 will be described as an example. Further, in the present embodiment, the first wafer W1 and the second wafer W2 are joined by a joining device (not shown) provided outside the wafer processing system 1, and a polymerized wafer T is formed in advance.

First, after the cassette C containing the plurality of polymerized wafers T is placed on the cassette mounting table 10 of the carry-in / out block G1, the polymerized wafer T in the cassette C is taken out by the wafer transfer device 20. The polymerized wafer T taken out from the cassette C is transferred to the wafer transfer device 40 via the transition device 30, and then transferred to the blast processing device 60.

In the blast processing apparatus 60, as shown in FIG. 4A, the inhibitory film Ox is removed from the back surface W1b by injecting and spraying the slurry onto the inhibitory film Ox formed on the back surface W1b of the first wafer W1. (Blast processing: step S1 in FIG. 5).

In removing the inhibitory film Ox, the polymerized wafer T (first wafer W1) is rotated, and the blast nozzle 62 is directed above the first wafer W1 from the inside to the outside in the radial direction of the first wafer W1. To scan. As a result, the inhibitory film Ox can be appropriately removed on the entire surface of the back surface W1b of the first wafer W1. At this time, by selecting a nozzle having a narrow injection hole (for example, about 10 mm) as described above, the injection region of the slurry from the blast nozzle 62 may be narrowed, and the blast amount in the injection region may be uneven. It is suppressed.

Further, as shown in FIG. 6, in the present embodiment, the blast nozzle 62 is made to follow, and the cleaning liquid nozzle 63 and the gas nozzle 64 are scanned from the radial inside to the outside of the first wafer W1. The cleaning liquid nozzle 63 removes the slurry (abrasive material) ejected from the blast nozzle 62 onto the back surface W1b of the first wafer W1. Further, the gas nozzle 64 removes the liquid (slurry and cleaning liquid) on the back surface W1b of the first wafer W1.

In the present embodiment, the cleaning liquid nozzle 63 and the gas nozzle 64 are made to follow the blast nozzle 62 in this way, and the cleaning liquid and the gas are supplied to the back surface W1b of the first wafer W1. As a result, it is suppressed that the removal debris of the abrasive grains and the inhibitory film Ox remains on the first wafer W1 after the blast treatment, and the back surface W1b after the blast treatment, the wafer processing system 1 and the inside of the processing chamber in the post-process are inside. Can be appropriately suppressed from being contaminated. Further, by removing the liquid (slurry and cleaning liquid) on the back surface Wb of the first wafer W1 using gas immediately after the wet blasting treatment in this way, the generation of watermarks on the back surface W1b can be appropriately suppressed.

In the case of removing the peripheral portion We of the first wafer W1 as in the present embodiment, in other words, the peripheral portion We of the first wafer W1 in the later interface reforming device 70 and the internal reforming device 80. When the laser beam is irradiated only in the vicinity, it is not always necessary to remove the inhibitory film Ox on the entire surface of the back surface W1b. That is, as shown in FIG. 7, at least the inhibitory film Ox at the position corresponding to the peripheral edge We of the first wafer W1 irradiated with the laser beam is removed, and from the position where the peripheral edge modification layer M1 described later is planned to be formed. However, it is not necessary to remove the inhibitory membrane Ox on the inner side in the radial direction. In other words, the inhibitory film Ox may be removed at least in the annular region including directly above the peripheral edge We of the first wafer W1 which is the region irradiated with the laser beam.

More specifically, for example, when the inhibitory membrane Ox inhibits _{the transmission of laser light (CO 2} laser) for forming the unbonded region Ae, the inhibitory membrane Ox immediately above the planned formation position of the unbonded region Ae. You may try to remove only. Further, for example, when the inhibitory film Ox inhibits the transmission of the laser beam (YAG laser) for forming the peripheral modification layer M1 and the split modification layer M2, the peripheral modification layer M1 and the split modification layer M2 The inhibitory membrane Ox directly above may be removed along the planned formation position. Further, for example, since the laser beam may be irradiated with a radial deviation due to a processing error or the like, the inhibitory film Ox is formed from the inside in the radial direction from the unbonded region Ae or the position where the peripheral modification layer M1 is planned to be formed. It may be removed.

By reducing the removal area of the inhibitory film Ox formed on the back surface W1b in this way, the processing time can be shortened and the resource (amount of slurry used) can be reduced as compared with the case where the inhibitory film Ox is removed on the entire surface of the back surface W1b. It saves money, reduces costs, and saves energy.

Further, in the blast processing in the blast processing apparatus 60, the inspection mechanism 67 is used to inspect whether or not the inhibitory film Ox has been removed from the back surface W1b of the first wafer W1. The timing of inspection of the back surface W1b of the first wafer W1 by the inspection mechanism 67 is not particularly limited, and may be performed at the same time as the blasting process, for example, or the blasting process is performed at a predetermined time. It may be done later.

Further, for example, the blast nozzle 62 may be moved to perform the blast treatment on the entire surface of the back surface W1b, and then the inspection by the inspection mechanism 67 may be performed, and the blast treatment may be repeated based on the inspection result. Further, for example, after confirming by the inspection mechanism 67 that the removal of the inhibitory film Ox at the desired radial position of the first wafer W1 is completed, the blast nozzle 62 is moved, and this is moved from the inside to the outside in the radial direction of the back surface W1b. The blasting process may be sequentially performed from the inside in the radial direction by repeatedly performing the blasting process.

In the blast processing apparatus 60, the cleaning liquid may be supplied to the back surface W2b of the second wafer W2 together with the blast processing of the back surface W1b.

The polymerized wafer T from which the inhibitory film Ox on the back surface W1b of the first wafer W1 has been removed by blasting is then transferred to the interface reforming device 70 by the wafer transfer device 40. In the interface modifier 70, as shown in FIG. 4B, the interface between the first wafer W1 and the device layer D1 (more specifically, the interface) while rotating the layered wafer T (first wafer W1). _{(For example, a CO 2} laser having a wavelength of 8.9 μm to 11 μm) is irradiated on the above-mentioned laser light absorption layer formed in the above-mentioned laser light to form an unbonded region Ae (step S2 in FIG. 5).

In the unbonded region Ae, the interface between the first wafer W1 and the device layer D1 is modified or peeled off, and the bonding strength between the first wafer W1 and the second wafer W2 is reduced or eliminated. As a result, the annular unbonded region Ae and the first wafer W1 and the second wafer W2 are bonded to the interface between the first wafer W1 and the device layer D1 in the radial direction of the unbonded region Ae. A joint region (not shown) is formed. In the edge trim described later, the peripheral edge portion We of the first wafer W1 to be removed is removed, and the presence of the unbonded region Ae in this way appropriately removes the peripheral edge portion We. Can be done.

Further, in the present embodiment, prior to the formation of the unbonded region Ae, the inhibitory film Ox formed on the back surface W1b of the first wafer W1 is removed in step S1. As a result, the laser beam is irradiated to the absorption layer without being absorbed and reflected by the inhibitory film Ox, so that the unbonded region Ae can be appropriately formed.

The polymerized wafer T on which the unbonded region Ae is formed is then transferred to the internal reformer 80 by the wafer transfer device 40. In the internal reforming apparatus 80, as shown in FIGS. 4C and 8, the peripheral reforming layer M1 and the split reforming layer M2 are formed inside the first wafer W1 (step S3 in FIG. 5). The peripheral edge modification layer M1 and the crack C1 extending from the peripheral edge modification layer M1 serve as a base point for removing the peripheral edge portion We in the edge trim described later. The split-modified layer M2 and the crack C2 extending from the split-modified layer M2 serve as a base point for fragmenting the peripheral edge portion We to be removed. In the drawings used in the following description, the illustration of the split reforming layer M2 may be omitted in order to avoid complicated illustration.

Here, the formation position of the peripheral modification layer M1 is determined slightly radially inward from the inner end of the unbonded region Ae formed in step S2. Ideally, the peripheral modification layer M1 is formed at a position overlapping the boundary between the bonded region and the unbonded region Ae (hereinafter, simply referred to as “boundary”), but is displaced in the radial direction due to, for example, a processing error. May be formed. Then, when the peripheral edge modification layer M1 is formed at a position radially outward from the boundary, that is, in the unbonded region Ae, after the peripheral edge portion We is removed, the first wafer W2 is first. The wafer W1 may be in a floating state. In this respect, by controlling the peripheral modification layer M1 to be formed radially inside the boundary, for example, even if the formation position shifts due to a processing error, the position overlaps the boundary or is radially outside the boundary. Even if there is, the peripheral modification layer M1 can be formed at a position close to the boundary, and the peripheral modification layer M1 can be suppressed from being formed at a position radially outward from the boundary.

The polymerized wafer T in which the peripheral modification layer M1 and the split reforming layer M2 are formed inside the first wafer W1 is then conveyed to the peripheral edge removing device 50 by the wafer transfer device 40. In the peripheral edge removing device 50, as shown in FIG. 4D, the peripheral edge portion We of the first wafer W1 is removed, that is, the edge trimming process is performed (step S4 in FIG. 5). At this time, the peripheral edge portion We is peeled off from the central portion of the first wafer W1 with the peripheral edge modification layer M1 and the crack C1 as the base points, and the device layer D1 (second wafer W2) with the unbonded region Ae as the base point. Is peeled off from. Further, at this time, the peripheral portion We to be removed is fragmented with the split reforming layer M2 and the crack C2 as the base points.

In removing the peripheral portion We, a blade having a wedge shape, for example, may be inserted at the interface between the first wafer W1 and the second wafer W2 forming the polymerized wafer T. Further, for example, an air blow or a water jet may be injected to press and remove the peripheral portion We. As described above, in the edge trimming, by applying an impact to the peripheral edge portion We of the first wafer W1, the peripheral edge portion We is peeled off from the peripheral edge modifying layer M1 and the crack C1 as a base point. Further, as described above, since the unbonded region Ae reduces the bonding strength between the first wafer W1 and the second wafer W2, the peripheral portion We is appropriately removed.

The polymerized wafer T from which the peripheral portion We of the first wafer W1 has been removed is then transferred to the blast processing device 60 again by the wafer transfer device 40. In the blast processing apparatus 60, as shown in FIG. 4 (e), blast processing is performed to suppress the scattering of particles on the peripheral edge of the second wafer W2 after the peripheral edge We is removed (FIG. 5). Step S5).

FIG. 9 shows the surface of the second wafer W2 after the removal of the peripheral edge portion We, specifically, the exposed surface Fe of the surface film remaining on the peripheral edge portion of the second wafer W2 exposed by the removal of the peripheral edge portion We. As shown, residual film and particles (hereinafter referred to as "particle P and the like") remain. The particles P and the like may cause contamination of the inside of the wafer processing system 1, the inside of the cassette C, and other polymerized wafers T by peeling, dropping, or scattering during the transfer or process of the polymerized wafer T.

Therefore, in the present embodiment, as shown in FIG. 10A, the surface layer of the exposed surface Fe, which can be a source of particles P and the like, is blasted so that the particles P and the like adhered together with the surface layer portion of the exposed surface Fe. Is removed, thereby suppressing the peeling, falling, and scattering of particles P and the like. Further, in the blasting treatment of the exposed surface Fe, the exposed surface Fe may be cleaned and the liquid may be removed by the cleaning liquid nozzle 63 and the gas nozzle 64 in the same manner as the removal of the inhibitory film Ox in step S1.

Further, as shown in FIG. 9, the first wafer W1 and the second wafer W2 are formed at the joining interface between the first wafer W1 and the second wafer W2 after the peripheral portion We is removed at the time of joining the first wafer W1 and the second wafer W2. The edge void V (air layer) that has been formed may remain. This edge void V may cause the generation of particles P and the like by bursting due to the influence of heating and cooling, pressurization and depressurization of the polymerized wafer T in the subsequent process.

Therefore, in the blasting process of step S5, as shown in FIG. 10B, the depth of the second wafer W2 up to the depth at which the edge void V is exposed, that is, the bonding interface between the first wafer W1 and the second wafer W2. The surface film (device layer D1 and bonding film F1) remaining on the peripheral edge portion may be removed. Further, for example, as shown in FIG. 10 (c), the surface films (device layer D1, bonding film F1, bonding film F2, and device layer D2) are provided to a depth where the surface W2a of the second wafer W2 is exposed. It may be removed.

In the blast processing apparatus 60, the back surface W2b of the second wafer W2 may be cleaned together with the blast processing of the exposed surface Fe of the second wafer W2.

After that, the polymerized wafer T that has been completely processed is transferred to the cassette C of the cassette mounting table 10 by the wafer transfer device 20 via the transition device 30. In this way, a series of wafer processing in the wafer processing system 1 is completed. The polymerized wafer T subjected to a series of wafer processing is thinned by grinding the back surface W1b of the first wafer W1 in a processing device (not shown) provided outside the wafer processing system 1. To. At this time, since the edge trim of the first wafer W1 is performed in the wafer processing system 1, it is possible to suppress the formation of a knife edge shape on the peripheral edge portion We of the first wafer W1.

According to the above embodiment, prior to the irradiation of the inside of the laminated wafer T with the laser beam, the laser beam inhibitor film Ox formed on the back surface W1b of the first wafer W1 which is the incident surface of the laser beam is blasted. Remove by processing. As a result, the laser light is suppressed from being absorbed and reflected by the inhibitory film Ox, so that the laser light can be appropriately irradiated to a desired position inside the layered wafer T, that is, the first wafer. The peripheral edge We of W1 can be appropriately peeled off from the second wafer W2.

At this time, since the slurry ejected from the blast nozzle 62 is removed from the back surface W1b by the cleaning liquid supplied from the cleaning liquid nozzle 63, the back surface W1b after the blast treatment and the inside of the wafer processing system 1 are contaminated. It can be suppressed appropriately. Furthermore, by removing the liquid supplied on the back surface W1b in the blast treatment by the gas nozzle 64, it is possible to appropriately suppress the generation of watermarks on the back surface W1b.

Further, in the present embodiment, the entire surface of the back surface W1b is blasted by moving the blast nozzle 62 in the horizontal direction in a state where the polymerized wafer T (first wafer W1) is rotated. As a result, the slurry or cleaning liquid sprayed on the back surface W1b flows outward in the radial direction due to the centrifugal force, so that it is possible to more appropriately suppress the contamination on the back surface W1b after the blast treatment.

The amount of the inhibitory membrane Ox removed by the blast treatment can be controlled, for example, by the supply time of the slurry with respect to the back surface W1b. However, when the injection pressure of the slurry, the scan speed of the blast nozzle 62, and the rotation speed of the polymerized wafer T are controlled to be constant, the relative rotation speed of the polymerized wafer T with respect to the blast nozzle 62 is blasted with respect to the first wafer W1. It varies depending on the relative radial position of the nozzle 62. Therefore, the relative supply time of the slurry changes according to the radial position of the blast nozzle 62, and the amount of the inhibitory film Ox removed may become non-uniform in the plane of the back surface W1b.

Therefore, in the present embodiment, when the inhibitory film Ox is removed on the entire surface of the back surface W1b, the injection pressure of the slurry, the scanning speed of the blast nozzle 62, and the scanning speed of the blast nozzle 62 are determined according to the relative radial position of the first wafer W1 with respect to the blast nozzle 62. Alternatively, it is desirable to control the rotation speed of the laminated wafer T. Specifically, in the radial outer blast treatment of the back surface W1b where the relative rotation speed of the polymerized wafer T with respect to the blast nozzle 62 becomes small, the injection pressure is increased so as to increase the amount of the inhibitory film Ox removed. It is desirable to reduce the scanning speed or increase the rotation speed.

Further, when the injection pressure of the slurry from the blast nozzle 62 to the inhibitory film Ox is controlled to be constant, the thickness of the inhibitory film Ox remaining on the back surface W1b decreases with the removal of the inhibitory film Ox. Along with this, the impact of the first wafer W1 on the back surface W1b becomes large. When the thickness of the inhibitory film Ox is reduced and the impact on the back surface W1b is increased in this way, the blast treatment affects not only the inhibitory film Ox but also the first wafer W1. In such a case, the back surface W1b of the first wafer W1 becomes rough, and there is a possibility that the laser beam cannot be irradiated to a desired position.

Therefore, in the blast treatment in the blast treatment device 60, the collision pressure of the slurry with respect to the back surface W1b is adjusted according to, for example, the residual thickness of the inhibitory film Ox detected by the inspection mechanism 67 and the blast treatment time (hereinafter, “impact adjustment””. It is desirable to do. The impact adjustment with respect to the back surface W1b can be performed, for example, by controlling the gas pressure (injection pressure) from the gas supply source 62b with respect to the blast nozzle 62.

Further, for example, the impact adjustment on the back surface W1b can be performed by forming a water film with the cleaning liquid supplied from the cleaning liquid nozzle 63. Specifically, the cleaning liquid is supplied to the back surface W1b to form a water film prior to the supply of the slurry from the blast nozzle 62, and the back surface W1b is blasted through the water film to have an impact on the back surface W1b. Can be reduced. Further, by adjusting the thickness of the water film from the back surface W1b (the amount of the cleaning liquid discharged from the cleaning liquid nozzle 63), the impact on the back surface W1b can be easily adjusted.

Further, for example, the impact adjustment to the back surface W1b may be performed by providing the blast processing apparatus 60 with a plurality of blast nozzles (not shown) for injecting slurries having different abrasive grain sizes of the abrasive. Specifically, when the thickness of the inhibitory film Ox is large and the impact on the back surface W1b is small, a coarse blast treatment is performed using a slurry containing an abrasive having a large abrasive particle size. Then, after the thickness of the inhibitory film Ox is reduced and the impact on the back surface W1b is increased, a finish blast treatment is performed using a slurry containing an abrasive having a small abrasive particle size. In this way, by changing the abrasive particle size of the slurry used for the blast treatment according to the thickness of the inhibitory film Ox, the impact on the back surface W1b can be appropriately adjusted.

Further, for example, the adjustment of the impact on the back surface W1b can be controlled by the relative angle of the blast nozzle 62 with respect to the back surface W1b, that is, the incident angle of the slurry with respect to the back surface W1b. Specifically, as compared with the case where the slurry is jetted perpendicularly to the back surface W1b, the impact is reduced when the incident angle of the slurry is inclined in the forward direction with the rotation direction of the laminated wafer T, and the laminated wafer The impact increases when the T is tilted in the direction opposite to the rotation direction. At this time, by adjusting the rotation speed of the polymerized wafer T, the impact on the back surface W1b can be adjusted more appropriately. When controlling the incident angle of the slurry in this way, the blast nozzle 62 may be tilted relative to the back surface W1b as described above, or the polymerized wafer T with respect to the blast nozzle 62 having a fixed injection angle. The rotation direction and rotation speed may be changed.

As described above, the surface of the back surface W1b and the exposed surface Fe that have been blasted in the polymerized wafer T may be roughened due to the impact of the blast treatment. Therefore, the treated surface to which the blasting treatment has been performed may be further subjected to a wet etching treatment. The wet etching process may be performed inside the blast processing device 60, or may be performed, for example, in an etching processing unit (not shown) independently provided outside the blast processing device 60. By performing the wet etching treatment after the blasting treatment in this way, for example, even if the treated surface is roughened by the blasting treatment, the treated surface can be prepared and the laser beam can be appropriately irradiated.

In the above embodiment, the blast nozzle 62, the cleaning liquid nozzle 63, and the gas nozzle 64 are provided side by side, and the back surface W1b is cleaned and the liquid is removed from the back surface Wb at the same time as the blasting process by the blast nozzle 62. Cleaning and removal of liquid do not necessarily have to be performed at the same time. That is, for example, after the blasting treatment of the entire surface of the back surface W1b is completed, the cleaning and liquid removal may be performed independently of the blasting treatment by the cleaning liquid nozzle 63 and the gas nozzle 64.

Further, when the back surface W1b is washed independently of the blast treatment, in other words, when the slurry and the cleaning liquid are not collected at the same time in the cup body 65 of the blast treatment device 60, the slurry used for the blast treatment is used. It may be recycled and used again for blasting.

As shown in FIG. 11, the cup body 65 of the blast processing apparatus 100 according to the second embodiment is connected to a discharge unit 66 that discharges the collected slurry and cleaning liquid to the drainage line. Further, in the present embodiment, the drainage line connected to the discharge unit 66 is branched and connected to the slurry recycling system 101 (corresponding to the “recycling mechanism” according to the present disclosure) used for the blast treatment. A switching valve (not shown) is provided at the branch of the drainage line to which the recycling system 101 is connected. The recycling system 101 collects a part of the mixed solution of the slurry recovered in the cup body 65 and the removal dust of the inhibitory membrane Ox, removes the removal dust and the like which are impurities, and then again to the slurry supply unit 62a. And supply the used slurry. By recycling the slurry used in the blast treatment in this way and using it again in the blast treatment, resources (amount of slurry used) can be saved and costs can be reduced.

Further, when the back surface W1b is washed and the liquid is removed independently of the blasting treatment inside the blasting treatment device, the blasting treatment device includes a first cup body for collecting the slurry used for the blasting treatment and a first cup body. It may have a double cup structure including a second cup body for discharging the cleaning liquid used for cleaning the back surface W1b. Specifically, as shown in FIG. 12, the blast processing apparatus 200 according to the third embodiment is supplied from the first cup body 201 for collecting the slurry injected from the blast nozzle 62 and the cleaning liquid nozzle 63. It has a second cup body 202 for discharging the cleaning liquid.

A discharge unit 203 for discharging the collected slurry to the drainage line is connected to the first cup body 201. Further, in the present embodiment, the drainage line connected to the discharge unit 203 is branched and connected to the slurry recycling system 101 used for the blast treatment. A switching valve (not shown) is provided at the branch of the drainage line to which the recycling system 101 is connected. Further, the first cup body 201 is provided with an elevating mechanism 201a, which is configured to be elevating and lowering inside the blast processing device 200. Note that FIG. 12A shows a state in which the first cup body 201 is raised, and FIG. 12B shows a state in which the first cup body 201 is lowered. Further, the opening of the first cup body 201 is configured to have substantially the same diameter as, for example, the chuck 61, and when the cleaning liquid is supplied to the first wafer W1, in other words, the lowering shown in FIG. 12 (b). At times, it is configured to prevent the cleaning liquid from flowing into the interior.

The second cup body 202 is configured to surround the periphery of the first cup body 201, for example, and is connected to a discharge unit 204 for discharging the cleaning liquid supplied to the back surface W1b.

In the blast processing apparatus 200 according to the third embodiment, a part of the slurry used for the blast processing is recovered in the recycling system 101 by raising the first cup body 201 during the blast processing of the polymerized wafer T. Then, the used slurry is supplied to the slurry supply unit 62a again. Further, when cleaning the polymerized wafer T, the cleaning liquid is discharged to the discharge unit 204 by lowering the first cup body 201. In this way, by independently providing discharge (recovery) routes for the slurry and cleaning liquid, the slurry can be appropriately recycled and resources (used) even when blasting and cleaning are performed in the same device. The amount of slurry to be recycled) can be saved and the cost can be reduced. Further, according to the present embodiment, since it is not necessary to independently provide a cleaning device (not shown) outside the blast processing device 60, it is possible to save space in the wafer processing system 1.

In the above embodiment, after the series of wafer processing in the wafer processing system 1 is completed, the first wafer W1 is thinned by a processing apparatus (not shown) provided outside the wafer processing system 1. However, the thinning of the first wafer W1 may be performed inside the wafer processing system 1.

Specifically, for example, as in the wafer processing system 300 shown in FIG. 13, a processing device 301 for grinding the back surface of the first wafer W1 to thin the polymerized wafer T may be provided. The number and arrangement of processing devices are not particularly limited and can be set arbitrarily. Further, at this time, the timing of thinning the first wafer W1 by the processing apparatus 301 is not particularly limited. For example, it may be performed after the blasting process of the exposed surface Fe of the second wafer W2 (step S5 in FIG. 5), or after the removal of the peripheral edge We of the first wafer W1 (step S4 in FIG. 5). Therefore, it may be performed before the blasting process of the exposed surface Fe (step S5 in FIG. 5).

In the above embodiment, by providing the cleaning liquid nozzle 63 and the gas nozzle 64 inside the blast processing device 60, the inhibitory film Ox was removed and the back surface W1b was cleaned inside the blast processing device 60. In other words, in the wafer processing system 1 according to the above embodiment, the blast processing device and the cleaning device are integrally configured. However, the configuration of the blast processing device 60 is not limited to this, and for example, the blast processing device 60 and the peripheral edge removing device 50 may be integrally configured. Further, at this time, the cleaning device may be further integrally configured.

Further, in the above embodiment, in the blast processing apparatus 60, the back surface W1b of the first wafer W1 is subjected to the wet blast treatment, but the blast treatment applied in the blast processing apparatus 60 may be the drive last treatment. ..

In the above embodiment, in the polymerized wafer T in which the first wafer W1 and the second wafer W2 are bonded, the peripheral portion We of the first wafer W1 is peeled off from the second wafer W2 as an example. However, the application example of the technology according to the present disclosure is not limited to this.

For example, the technique according to the present disclosure can be applied even when the first wafer W1 is separated into a front surface W1a side and a back surface W1b side and thinned. Specifically, first, as shown in FIG. 14A, the inhibitory film Ox on the entire surface of the back surface W1b of the first wafer W1 is removed by a blast treatment. After that, by irradiating the inside of the polymerized wafer T with a laser beam, an unbonded region Ae and a peripheral modification layer M1 are formed as shown in FIG. 14 (b), and further used as a starting point for separation of the first wafer W1. The separation surface modification layer M3 is formed along the surface direction of the first wafer W1. The unbonded region Ae is formed in the annular region on the radial outer side of the peripheral modification layer M1 corresponding to the peripheral edge portion We of the first wafer W1. The separation surface modification layer M3 is formed in a region inside the peripheral modification layer M1 in the first wafer W1 in the radial direction. In the polymerized wafer T in which the unbonded region Ae, the peripheral modification layer M1 and the separation surface modification layer M3 were formed, the first wafer W1 was subsequently arranged on the surface W1a side as shown in FIG. 14 (c). It is separated from the back surface W1b side and thinned. By removing the inhibitory film Ox formed on the back surface W1b of the first wafer W1 in this way, it is suppressed that the laser beam is absorbed and reflected by the inhibitory film Ox, and the unbonded region Ae and the peripheral edge are appropriately suppressed. The modified layer M1 and the separation surface modified layer M3 can be formed.

Further, for example, the technique according to the present disclosure is a case where the entire first wafer W1 is removed from the second wafer W2 and the device layer D1 formed on the first wafer W1 is transferred to the second wafer W2. It can also be applied in. Specifically, first, as shown in FIG. 15A, the inhibitory film Ox on the entire surface of the back surface W1b of the first wafer W1 is removed. Then, by irradiating the entire interface between the first wafer W1 and the device layer D1 with a laser beam, an unbonded region Ae is formed as shown in FIG. 15 (b). In the polymerized wafer T on which the unbonded region Ae is formed, the first wafer W1 is subsequently peeled off from the unbonded region Ae as a base point, so that the device layer D1 becomes the second device layer D1. Transferred to wafer W2. By removing the inhibitory film Ox formed on the back surface W1b of the first wafer W1 in this way, it is suppressed that the laser beam is absorbed and reflected by the inhibitory film Ox, and the unbonded region Ae is appropriately formed. can.

The embodiments disclosed this time should be considered to be exemplary and not restrictive in all respects. The above embodiments may be omitted, replaced or modified in various forms without departing from the scope of the appended claims and their gist.

D1 device layer D2 device layer F1 bonding film F2 bonding film Ox inhibition film T polymerization wafer W1 first wafer W1b back surface W2 second wafer

Claims (20)

It is a method for treating a polymerized substrate in which a first substrate formed by laminating surface films and a second substrate are bonded to each other.
The surface film contains an absorption layer of laser light and contains.
To remove the laser beam obstructing film formed on the back surface of the first substrate by blasting, and
Irradiating the absorption layer with laser light from the back surface side of the first substrate and
A substrate processing method comprising peeling the first substrate from the second substrate. The surface film formed on the first substrate includes a device layer on which a plurality of devices are formed.
The substrate processing method according to claim 1, wherein the device layer formed on the first substrate is left on the second substrate after the first substrate is peeled off. The substrate processing method according to claim 1 or 2, wherein in removing the inhibitory film, a cleaning liquid is further supplied to the back surface of the first substrate. The substrate processing method according to any one of claims 1 to 3, wherein in the removal of the inhibitory film, gas is further supplied to the back surface of the first substrate. The substrate treatment method according to any one of claims 1 to 4, wherein the blast treatment is repeatedly performed using a slurry containing abrasive grains having different particle sizes. In removing the inhibitory film, the polymerized substrate is rotated, and the nozzle for performing the blast treatment is scanned from the radial inside to the outside of the first substrate.
The substrate processing method according to any one of claims 1 to 5, wherein the scanning speed of the nozzle on the radial outer side of the first substrate is made slower than the scanning speed on the radial inner side. The substrate processing method according to any one of claims 1 to 6, wherein in the peeling of the first substrate, at least the peripheral edge portion of the first substrate is peeled from the second substrate. The substrate processing method according to claim 7, wherein the inhibitory film is removed in an annular region including the peripheral portion, which is the irradiation range of the laser beam. The substrate processing method according to claim 7 or 8, which comprises blasting the exposed surface of the second substrate exposed by peeling off the peripheral edge portion. The substrate treatment method according to any one of claims 1 to 9, wherein impurities are removed from the slurry used for the blast treatment and the slurry is used again for the blast treatment. The substrate processing method according to any one of claims 1 to 10, further comprising performing a wet etching treatment on the treated surface to which the blasting treatment has been performed. A substrate processing device for processing a polymerized substrate to which a first substrate and a second substrate formed by laminating surface films are bonded.
The surface film contains an absorption layer of laser light and contains.
A blast processing unit provided with a blast nozzle for removing a laser beam obstructing film formed on the back surface of the first substrate, and a blast processing unit.
A laser irradiation unit that irradiates the absorption layer with laser light from the back surface side of the first substrate, and a laser irradiation unit.
A substrate processing apparatus having a peeling portion for peeling the first substrate from the second substrate. The substrate processing apparatus according to claim 12, wherein the blast processing unit includes a cleaning liquid nozzle for supplying a cleaning liquid to the back surface of the first substrate. The substrate processing apparatus according to claim 12, wherein the blast processing unit includes a gas nozzle for supplying gas to the back surface of the first substrate. The peeling portion is any one of claims 12 to 14, wherein at least the peripheral edge portion of the first substrate is peeled from the second substrate with the modified layer formed inside the first substrate as a base point. The substrate processing apparatus according to paragraph 1. The substrate processing apparatus according to claim 15, wherein the blast processing unit removes the inhibitory film in an annular region including the peripheral portion which is an irradiation range of the laser light. The substrate processing apparatus according to claim 15, wherein the blast processing unit performs blast processing on an exposed surface of the second substrate exposed by peeling of the peripheral edge portion. The substrate processing apparatus according to any one of claims 12 to 17, wherein the blast processing unit has a recycling mechanism for removing impurities from the slurry used for the blast processing and using the blast processing unit again. .. The blast processing unit is
The first cup body for collecting the slurry in the blasting process and
The substrate processing apparatus according to claim 18, further comprising a second cup body for discharging the cleaning liquid supplied to the treated surface to which the blast treatment has been performed. The substrate processing apparatus according to any one of claims 12 to 19, further comprising an etching processing unit for performing a wet etching treatment on a treated surface to which the blasting treatment has been performed.

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