Substrate processing method and substrate processing device

Abstract

A substrate processing method according to one embodiment of the present disclosure includes a first bonding step, a thinning step, and a peeling step. In the first bonding step, a polymerized substrate is formed by bonding a second substrate to a first surface of a first substrate having a device formed on the first surface. In the thinning step, the first substrate is thinned by grinding the first substrate side of the polymerized substrate. In the peeling step, the second substrate is peeled from the thinned first substrate. In the first bonding step, the first substrate and the second substrate are bonded by siloxane bonding.

Description

Substrate processing method and substrate processing apparatus

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

[0002] In recent years, for example, in the manufacturing process of semiconductor devices, substrates such as semiconductor wafers have become larger in diameter. Furthermore, in certain processes such as packaging, thinner substrates are required. For example, if large-diameter, thin substrates are transported or processed as they are, they may warp or crack.

[0003] For this reason, for example, in order to reinforce the thin substrate, a supporting substrate is bonded to the thin substrate, for example, by interposing an adhesive between the thin substrate and the supporting substrate (see Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2008-182016

[0005] The present disclosure provides a technique that can reduce variations in thickness of a thinned substrate.

[0006] A substrate processing method according to one aspect of the present disclosure includes a first bonding step, a thinning step, and a peeling step. The first bonding step forms an overlapped substrate by bonding a second substrate to a first surface of a first substrate having a device formed on the first surface. The thinning step thins the first substrate by grinding the first substrate side of the overlapped substrate. The peeling step peels the second substrate from the thinned first substrate. The first bonding step bonds the first substrate and the second substrate together using a siloxane bond.

[0007] According to the present disclosure, it is possible to reduce the variation in thickness of a thinned substrate. Note that the effects described herein are not necessarily limited to those described herein, and any of the effects described in the present disclosure may be achieved.

[0008] FIG. 1 is a schematic diagram showing an example of the configuration of a substrate processing apparatus according to an embodiment. FIG. 2 is a flowchart showing the procedure of a bonding process performed by the substrate processing apparatus according to an embodiment. FIG. 3 is a cross-sectional view showing an example of the configuration of a bonding unit according to an embodiment. FIG. 4 is a side view showing an example of the configuration of a laser irradiation unit according to an embodiment. FIG. 5 is an explanatory diagram showing how a laser beam is irradiated from a laser irradiation unit to a laminated substrate according to an embodiment. FIG. 6 is a schematic side view showing an example of the configuration of a delamination unit according to an embodiment. FIG. 7 is a schematic plan view showing an example of the configuration of a first holding unit according to an embodiment. FIG. 8 is a flowchart showing the procedure of a substrate processing according to an embodiment. FIG. 9 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 10 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 11 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 12 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 13 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 14 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 15 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 16 is a diagram for explaining one step of a substrate processing according to an embodiment. FIG. 17 is a diagram for explaining one step of a substrate processing according to an embodiment. Fig. 18 is a diagram for explaining one step of substrate processing according to an embodiment. Fig. 19 is a flowchart showing a procedure for substrate processing according to a modified embodiment. Fig. 20 is a diagram for explaining one step of substrate processing according to a modified embodiment. Fig. 21 is a diagram for explaining one step of substrate processing according to a modified embodiment. Fig. 22 is a diagram for explaining one step of substrate processing according to a modified embodiment. Fig. 23 is a diagram for explaining one step of substrate processing according to a modified embodiment.

[0009] Hereinafter, embodiments of a substrate processing method and a substrate processing apparatus disclosed herein will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments described below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of elements may differ from the actual situation. Furthermore, the dimensional relationships and ratios may differ between the drawings.

[0010] In addition, in the drawings referred to below, for ease of understanding, an orthogonal coordinate system may be shown in which the X-axis direction, Y-axis direction, and Z-axis direction, which are perpendicular to each other, are defined, and the positive Z-axis direction is the vertically upward direction.

[0011] In recent years, for example, in the manufacturing process of semiconductor devices, substrates such as semiconductor wafers have become larger in diameter. Furthermore, in certain processes such as packaging, thinner substrates are required. For example, if large-diameter, thin substrates are transported or processed as they are, they may warp or crack.

[0012] For this reason, for example, in order to reinforce the thin substrate, a support substrate is bonded to the thin substrate, and this bonding is performed, for example, by interposing an adhesive between the thin substrate and the support substrate.

[0013] On the other hand, in the conventional technology, there is a risk that the thickness of the thinned substrate will vary greatly due to the large variation in the film thickness of the adhesive after bonding. This is because in the polishing process for thinning the substrate, the polished surface is processed to be flat with high precision, and therefore the variation in the film thickness of the adhesive directly results in the variation in the thinned substrate.

[0014] Therefore, there is a need for a technology that can overcome the above-mentioned problems and reduce the variation in thickness of thinned substrates.

[0015] <Configuration of Substrate Processing Apparatus> First, the configuration of a substrate processing apparatus 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing an example of the configuration of a substrate processing apparatus 1 according to an embodiment.

[0016] 1 forms a laminated substrate T by bonding a lower wafer W1 and an upper wafer W2 together. The substrate processing apparatus 1 also peels off the lower wafer W1 from the laminated substrate T formed by bonding the lower wafer W1 and the upper wafer W2 together.

[0017] The lower wafer W1 and the upper wafer W2 are, for example, single crystal silicon wafers. The lower wafer W1, the upper wafer W2, and the laminated substrate T in the substrate processing method according to the embodiment will be described in detail later.

[0018] In the description of the configuration of the substrate processing apparatus 1, the surface of the lower wafer W1 that is bonded to the upper wafer W2 will be referred to as the "bonding surface W1j," and the surface opposite the bonding surface W1j will be referred to as the "non-bonding surface W1n." Furthermore, the surface of the upper wafer W2 that is bonded to the lower wafer W1 will be referred to as the "bonding surface W2j," and the surface opposite the bonding surface W2j will be referred to as the "non-bonding surface W2n."

[0019] 1, the substrate processing apparatus 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 is located on the positive Y-axis side of the processing station 3 and is integrally connected to the processing station 3.

[0020] The loading / unloading station 2 includes a mounting table 10 and a transport area 20. The mounting table 10 includes a plurality of mounting plates 11. Each mounting plate 11 is loaded with one of cassettes C1 to C4, each of which stores a plurality of substrates (e.g., 25 substrates) in a horizontal position.

[0021] The cassette C1 can accommodate a plurality of lower wafers W1. The cassette C2 can accommodate a plurality of upper wafers W2. The cassette C3 can accommodate a plurality of superposed substrates T. The cassette C4 is, for example, a cassette for recovering a defective substrate. Note that the number of cassettes C1 to C4 placed on the placement plate 11 is not limited to that shown in the figure.

[0022] The transport area 20 is located adjacent to the negative Y-axis side of the mounting table 10. The transport area 20 is provided with a transport path 21 extending in the X-axis direction and a transport device 22 that is movable along the transport path 21. The transport device 22 is movable not only in the Y-axis direction but also in the X-axis direction and is rotatable around the Z-axis.

[0023] The transfer device 22 transfers the lower wafer W1, the upper wafer W2, and the laminated substrate T between the cassettes C1 to C4 placed on the mounting plate 11 and a third processing block G3 of the processing station 3, which will be described later.

[0024] For example, four processing blocks G1, G2, G3, and G4 are provided in the processing station 3. The first processing block G1 is located on the rear side (positive X-axis side in FIG. 1 ) of the processing station 3. The second processing block G2 is located on the front side (negative X-axis side in FIG. 1 ) of the processing station 3.

[0025] The third processing block G3 is located on the opposite side of the processing station 3 from the loading / unloading station 2 (the negative Y-axis side in FIG. 1 ). The fourth processing block G4 is located on the loading / unloading station 2 side of the processing station 3 (the positive Y-axis side in FIG. 1 ).

[0026] The first processing block G1 is provided with a surface modification unit 30 that modifies the bonding surface W1j (see FIG. 3) of the lower wafer W1 and the bonding surface W2j (see FIG. 3) of the upper wafer W2. The surface modification unit 30 modifies the SiO 2 on the bonding surface W1j of the lower wafer W1 and the bonding surface W2j of the upper wafer W2. ２ The bond is cut to form single-bonded SiO, thereby modifying the bonding surfaces W1j and W2j so that they are easily made hydrophilic thereafter.

[0027] Specifically, in the surface modification unit 30, for example, oxygen gas or nitrogen gas serving as a processing gas is excited to be plasmatized and ionized in a reduced pressure atmosphere. Then, the oxygen ions or nitrogen ions are irradiated onto the bonding surfaces W1j and W2j of the lower wafer W1 and the upper wafer W2, whereby the bonding surfaces W1j and W2j are subjected to plasma processing and modified.

[0028] The first processing block G1 also includes a surface hydrophilization unit 31. The surface hydrophilization unit 31 hydrophilizes the bonding surface W1j of the lower wafer W1 and the bonding surface W2j of the upper wafer W2 using, for example, pure water, and cleans the bonding surfaces W1j and W2j.

[0029] Specifically, the surface hydrophilization unit 31 supplies pure water onto the lower wafer W1 or the upper wafer W2 while rotating the lower wafer W1 or the upper wafer W2 held by, for example, a spin chuck.

[0030] As a result, the pure water supplied onto the lower wafer W1 or the upper wafer W2 spreads over the bonding surface W1j of the lower wafer W1 or the bonding surface W2j of the upper wafer W2, making the bonding surfaces W1j and W2j hydrophilic.

[0031] In the example of Figure 1, the surface modification unit 30 and the surface hydrophilization unit 31 are arranged side by side, but the surface hydrophilization unit 31 may be stacked above or below the surface modification unit 30.

[0032] The second processing block G2 is provided with a bonding unit 40. The bonding unit 40 bonds the hydrophilized bonding surface W1j of the lower wafer W1 and the bonding surface W2j of the upper wafer W2 by siloxane bonding (Si—O—Si). The specific configuration of the bonding unit 40 will be described later.

[0033] The second processing block G2 also includes a laser irradiation unit 41. The laser irradiation unit 41 irradiates the interface of the laminated substrate T at which separation is desired with laser light L (see FIG. 4). The specific configuration of the laser irradiation unit 41 will be described later.

[0034] In the example of FIG. 1, the joining unit 40 and the laser irradiation unit 41 are arranged side by side, but the joining unit 40 may be stacked above or below the laser irradiation unit 41.

[0035] The third processing block G3 is located with a separation unit 50. The separation unit 50 separates the lower wafer W1 from the laminated substrate T in which the lower wafer W1 and the upper wafer W2 are bonded together. The specific configuration of the separation unit 50 will be described later.

[0036] The fourth processing block G4 is provided with a transition device 51. The transition device 51 temporarily stores the lower wafer W1, the upper wafer W2, or the laminated substrate T. The number of transition devices 51 may be plural.

[0037] A transfer region 60 is located in an area surrounded by the first processing block G1 to the fourth processing block G4. A transfer device 61 is located in the transfer region 60. The transfer device 61 has a transfer arm that is movable, for example, vertically, horizontally, and around a vertical axis.

[0038] The transfer device 61 moves within the transfer region 60 to transfer the lower wafer W1, the upper wafer W2, and the laminated substrate T to predetermined units within the first to fourth processing blocks G1 to G4 adjacent to the transfer region 60.

[0039] The substrate processing apparatus 1 also includes a control device 70. The control device 70 controls the operation of the substrate processing apparatus 1. The control device 70 is, for example, a computer, and includes a control unit and a storage unit (not shown).

[0040] The control unit includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), input / output ports, etc., and various circuits. The CPU of such a microcomputer reads and executes programs stored in the ROM to realize the control described below. The control unit may be one or more circuits, or may be provided as an integrated unit or partially separated.

[0041] The storage unit is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk.

[0042] The program read by the control unit may be one that has been recorded on a computer-readable recording medium and that has been installed from the recording medium into the storage unit of the control device 70. Examples of computer-readable recording media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

[0043] <Bonding Process> Next, an example of the bonding process performed by the substrate processing apparatus 1 according to the embodiment will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the procedure of the bonding process performed by the substrate processing apparatus 1 according to the embodiment.

[0044] The joining process according to the embodiment includes, for example, steps S01 to S05. Steps S01 to S05 are performed under the control of the control device 70 (see FIG. 1). Note that the joining process according to the embodiment does not need to include all of steps S01 to S05, and it is sufficient that it includes at least step S05. Furthermore, the joining process according to the embodiment may include processing other than step S05.

[0045] First, the cassette C1 (see FIG. 1) containing a plurality of lower wafers W1 (see FIG. 1) and the cassette C2 (see FIG. 1) containing a plurality of upper wafers W2 (see FIG. 1) are placed on the mounting table 10 (see FIG. 1) of the carry-in / out station 2 (see FIG. 1). In addition, an empty cassette C3 (see FIG. 1) is placed on the mounting table 10 of the carry-in / out station 2.

[0046] Next, the transfer device 22 (see FIG. 1) takes out the lower wafer W1 from the cassette C1 and transfers it to the transition device 51 (see FIG. 1). Thereafter, the transfer device 61 (see FIG. 1) takes out the lower wafer W1 from the transition device 51 and transfers it to the surface modification unit 30 (see FIG. 1).

[0047] Next, the surface modification unit 30 modifies the bonding surface W1j (see FIG. 3) of the lower wafer W1 (step S01). The modification of the bonding surface W1j is performed with the bonding surface W1j facing upward. Thereafter, the transfer device 61 removes the lower wafer W1 from the surface modification unit 30 and transfers it to the surface hydrophilization unit 31 (see FIG. 1).

[0048] Next, the surface hydrophilization unit 31 hydrophilizes the bonding surface W1j of the lower wafer W1 (step S02). The hydrophilization of the bonding surface W1j is performed with the bonding surface W1j facing upward. Thereafter, the transfer device 61 removes the lower wafer W1 from the surface hydrophilization unit 31 and transfers it to the bonding unit 40 (see FIG. 1).

[0049] In parallel with the above-described processing for the lower wafer W1, the following processing for the upper wafer W2 is performed. First, the transfer device 22 takes out the upper wafer W2 from the cassette C2 and transfers it to the transition device 51. Then, the transfer device 61 takes out the upper wafer W2 from the transition device 51 and transfers it to the surface modification unit 30.

[0050] Next, the surface modification unit 30 modifies the bonding surface W2j of the upper wafer W2 (step S03). The modification of the bonding surface W2j is performed with the bonding surface W2j facing upward. Thereafter, the transfer device 61 removes the upper wafer W2 from the surface modification unit 30 and transfers it to the surface hydrophilization unit 31.

[0051] Next, the surface hydrophilization unit 31 hydrophilizes the bonding surface W2j of the upper wafer W2 (step S04). The hydrophilization of the bonding surface W2j is performed with the bonding surface W2j facing upward. Thereafter, the transfer device 61 removes the upper wafer W2 from the surface hydrophilization unit 31 and transfers it to the bonding unit 40.

[0052] Next, the bonding unit 40 turns the upper wafer W2 upside down so that the bonding surface W2j of the upper wafer W2 faces downward. Thereafter, the bonding unit 40 bonds the lower wafer W1 and the upper wafer W2 together to manufacture the laminated substrate T (see FIG. 1 ) (step S05). Thereafter, the transfer device 61 removes the laminated substrate T from the bonding unit 40 and transfers it to the transition device 51.

[0053] Finally, the transfer device 22 takes out the laminated substrate T from the transition device 51 and transfers it to the cassette C3 on the mounting table 10. This completes the series of bonding processes.

[0054] <Joining Unit> Next, an example of the configuration of the joining unit 40 according to the embodiment will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing an example of the configuration of the joining unit 40 according to the embodiment.

[0055] The joining unit 40 includes a lower holding section 110 , an upper holding section 120 , a lower imaging section 130 , an upper imaging section 150 , a moving section 170 , and a pushing section 190 .

[0056] The lower holding unit 110 holds the lower wafer W1 from below with the bonding surface W1j of the lower wafer W1 facing upward, and the upper holding unit 120 holds the upper wafer W2 from above with the bonding surface W2j of the upper wafer W2 facing downward.

[0057] The lower imaging unit 130 is provided, for example, in the lower holding unit 110, and images the upper wafer W2 held by the upper holding unit 120. The upper imaging unit 150 is provided, for example, in the upper holding unit 120, and images the lower wafer W1 held by the lower holding unit 110.

[0058] The moving unit 170 moves the lower holding unit 110 and the upper holding unit 120 relatively in the horizontal and vertical directions. In this embodiment, the moving unit 170 moves the lower holding unit 110, but it may also move the upper holding unit 120. The moving unit 170 may also rotate the lower holding unit 110 or the upper holding unit 120 around a vertical axis.

[0059] The lower holding portion 110 is partitioned into a plurality of (for example, two) regions 110a and 110b. These regions 110a and 110b are provided in this order from the center toward the periphery of the lower holding portion 110. The region 110a has a circular shape in a plan view, and the region 110b has an annular shape in a plan view.

[0060] The lower holding unit 110 is capable of vacuum-suctioning the lower wafer W1 for each of the regions 110a and 110b.

[0061] The lower holding part 110 is provided with a plurality of holding pins 115 that can be raised and lowered in the vertical direction. The lower wafer W1 is placed on the upper ends of the plurality of holding pins 115. The lower wafer W1 may be vacuum-sucked to the upper ends of the plurality of holding pins 115.

[0062] As the multiple holding pins 115 rise, they protrude from the holding surface of the lower holding part 110. In this state, the multiple holding pins 115 receive the lower wafer W1 from the transfer device 61. Thereafter, the multiple holding pins 115 descend, and the lower wafer W1 is brought into contact with the holding surface of the lower holding part 110.

[0063] Next, the lower holding part 110 horizontally vacuum-sucks the lower wafer W1 in the respective regions 110a and 110b by operating the vacuum pumps 112a and 112b.

[0064] The upper holding portion 120 is partitioned into multiple (e.g., three) regions 120a, 120b, and 120c. These regions 120a, 120b, and 120c are provided in this order from the center toward the periphery of the upper holding portion 120. The region 120a has a circular shape in a plan view, and the regions 120b and 120c have annular shapes in a plan view.

[0065] Suction pipes 121 a, 121 b, and 121 c are provided independently for the respective regions 120 a, 120 b, and 120 c. Different vacuum pumps 122 a, 122 b, and 122 c are connected to the respective suction pipes 121 a, 121 b, and 121 c. The upper holding unit 120 can vacuum-suck the upper wafer W2 for each of the regions 120 a, 120 b, and 120 c.

[0066] The upper holding part 120 is provided with a plurality of holding pins 125 that can be raised and lowered in the vertical direction. The plurality of holding pins 125 are connected to a vacuum pump 126, and vacuum-suck the upper wafer W2 by operating the vacuum pump 126. The upper wafer W2 is vacuum-sucked to the lower ends of the plurality of holding pins 125. Ring-shaped suction pads may be used instead of the plurality of holding pins 125.

[0067] As the holding pins 125 move downward, they protrude from the holding surface of the upper holding part 120. In this state, the holding pins 125 vacuum-suck the upper wafer W2 and receive it from the transfer device 61.

[0068] Thereafter, the plurality of holding pins 125 rise, and the upper wafer W2 comes into contact with the holding surface of the upper holding part 120. Next, the upper holding part 120 operates the vacuum pumps 122a, 122b, and 122c to horizontally vacuum-suck the upper wafer W2 in the respective regions 120a, 120b, and 120c.

[0069] Furthermore, a through-hole 123 that passes vertically through the upper holding part 120 is formed in the center of the upper holding part 120. A pushing part 190 is inserted into the through-hole 123. The pushing part 190 pushes down the center of the upper wafer W2, which is arranged at a distance from the lower wafer W1, and brings the upper wafer W2 into contact with the lower wafer W1.

[0070] The pushing unit 190 has a pushing pin 191 and an outer cylinder 192 that serves as a lifting guide for the pushing pin 191. The pushing pin 191 is inserted into the through-hole 123 by, for example, a drive unit (not shown) having a built-in motor, and protrudes from the holding surface of the upper holding unit 120 to push down the center of the upper wafer W2.

[0071] <Laser irradiation unit> Next, an example of the configuration of the laser irradiation unit 41 according to the embodiment will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a side view showing an example of the configuration of the laser irradiation unit 41 according to the embodiment.

[0072] 4, the laser irradiation unit 41 has a chuck 200. The chuck 200 holds the upper surface of the laminated substrate T. The chuck 200 suction-holds the entire non-bonding surface W1n (see FIG. 3) of the lower wafer W1. The chuck 200 may suction-hold only a part of the non-bonding surface W1n.

[0073] The chuck 200 is provided with lifting pins (not shown) for supporting and raising and lowering the laminated substrate T from below. The lifting pins are inserted into through holes (not shown) formed through the chuck 200 and are configured to be freely raised and lowered.

[0074] The chuck 200 is supported by a slider table 202 via an air bearing 201. A rotation mechanism 203 is provided on the underside of the slider table 202. The rotation mechanism 203 has a built-in motor, for example, as a drive source. The chuck 200 is configured to be rotatable around the θ axis (vertical axis) by the rotation mechanism 203 via the air bearing 201.

[0075] The slider table 202 is configured to be movable along a rail 205 that is provided on a base 206 and extends in the Y-axis direction by a movement mechanism 204 provided on the underside of the slider table 202. The drive source of the movement mechanism 204 is not particularly limited, but a linear motor, for example, is used.

[0076] A laser irradiation unit 210 is provided above the chuck 200. The laser irradiation unit 210 has a laser head 211, an optical system 212, and a lens 213. The laser head 211 oscillates laser light L in pulses.

[0077] The optical system 212 adjusts the output by controlling the intensity and position of the laser light L or attenuating the laser light L. The lens 213 is a cylindrical member that irradiates the laser light L onto the laminated substrate T held by the chuck 200.

[0078] The laser light L emitted from the laser irradiation unit 210 according to the embodiment is, for example, CO ２ This CO ２ The wavelength range of the laser light is the infrared wavelength range, for example, 8.9 μm to 11 μm.

[0079] The laser light L emitted from the laser irradiation unit 210 passes through the upper wafer W2 and is irradiated onto the interface between the lower wafer W1 and the upper wafer W2. The lens 213 is configured to be movable up and down by a lifting mechanism (not shown).

[0080] 5 is an explanatory diagram showing how the laser irradiation unit 210 irradiates the superposed substrate T with laser light L in the embodiment. The pulsed laser light L irradiated from the laser irradiation unit 210 is irradiated in a spiral pattern from the outside to the inside of the superposed substrate T, for example, as shown in FIG.

[0081] The pulsed laser light L irradiated from the laser irradiation unit 210 may be irradiated, for example, in a concentric circle having a plurality of diameters, or may be irradiated along another path. Furthermore, the pulsed laser light L irradiated from the laser irradiation unit 210 may be irradiated only onto the outer periphery of the laminated substrate T as shown in FIG. 5 , or may be irradiated onto the entire surface of the laminated substrate T.

[0082] <Peeling Unit> Next, an example of the configuration of the peeling unit 50 according to this embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a schematic side view showing an example of the configuration of the peeling unit 50 according to this embodiment.

[0083] The peeling unit 50 includes a first holding section 310 , a second holding section 320 , a third holding section 330 , a peeling induction section 340 , a plurality of (here, two) lifting mechanisms 350 , and a support 360 .

[0084] The separation unit 50 suction-holds the lower wafer W1 side of the laminated substrate T from above using the first holding part 310, and suction-holds the upper wafer W2 side of the laminated substrate T from below using the second holding part 320. Then, the separation unit 50 moves the lower wafer W1 by the lifting mechanism 350 in a direction (here, the positive direction of the Z axis) away from the surface of the upper wafer W2.

[0085] As a result, the lower wafer W1 held by the first holding part 310 is continuously peeled from the upper wafer W2 from one end to the other end. Each component will be specifically described below.

[0086] The first holding part 310 suction-holds the non-bonding surface W1n (see FIG. 3) of the lower wafer W1 of the laminated substrate T. The first holding part 310 has an elastic member 311 and a plurality of suction parts 312.

[0087] The elastic member 311 is a thin plate-like member and is formed of, for example, a metal such as a metal plate. The elastic member 311 has an opening 311c in the center for passing the third holding part 330 therethrough. The elastic member 311 is disposed above the lower wafer W1 and facing the lower wafer W1.

[0088] The plurality of suction portions 312 are provided on a surface (here, the lower surface) of the elastic member 311 that faces the lower wafer W1. Each suction portion 312 has a main body portion 312a fixed to the elastic member 311 and a suction pad 312b provided below the main body portion 312a.

[0089] Each suction unit 312 is connected to a suction device 312d, such as a vacuum pump, via a suction pipe 312c. The first holding unit 310 suctions the non-bonding surface W1n of the lower wafer W1 with the plurality of suction units 312 by using the suction force generated by the suction device 312d. As a result, the lower wafer W1 is suction-held by the first holding unit 310.

[0090] Note that it is preferable that the suction pad 312b provided in the suction unit 312 be of a type that deforms little. This is because if the suction pad 312b deforms significantly when the lifting mechanism 350 (described later) pulls the first holding unit 310, the suction pad 312b may deform significantly along with the deformation, resulting in a risk of damaging the lower wafer W1 or the upper wafer W2.

[0091] Specifically, it is preferable to use, as the suction pad 312b, one having ribs on the suction surface, or a flat pad with a space height of 0.5 mm or less.

[0092] The configuration of the first holding portion 310 will now be described in more detail with reference to Fig. 7. Fig. 7 is a schematic plan view showing an example of the configuration of the first holding portion 310 according to the embodiment.

[0093] The elastic member 311 has a main body portion 311a and a plurality of (here, two) extending portions 311b. The main body portion 311a has an opening 311c in the center for allowing the third holding portion 330 to pass through. Here, the central portion of the main body portion 311a refers to a region including the center of the main body portion 311a. The plurality of suction portions 312 are located on the lower surface of the main body portion 311a, i.e., on the surface facing the laminated substrate T.

[0094] The multiple (here, two) extending portions 311b are portions formed by extending a portion of the outer periphery of the main body 311a. Specifically, one of the two extending portions 311b is a portion formed by extending a portion of the outer periphery of the main body 311a that is closest to the peeling starting point (the outer periphery on the negative Y-axis direction side) in the opposite direction to the peeling progression direction (the negative Y-axis direction side).

[0095] The other of the two extensions 311b is a portion of the outer periphery of the main body 311a that is located closest to the end point of the peeling (the outer periphery on the positive Y-axis direction side) and extends in the direction of peeling progress (the positive Y-axis direction side). Support members 351 of the lifting mechanism 350 are connected to the tips of the extensions 311b, respectively.

[0096] The plurality of (six in this example) suction portions 312 are located on the underside of the main body 311 a. As shown in Fig. 7 , three of the six suction portions 312 are located on the periphery of the outer periphery of the main body 311 a, at the outer periphery closest to the peeling starting point (the outer periphery in the negative Y-axis direction).

[0097] Two of the six suction portions 312 are positioned around the opening 311c of the main body 311a in a line in a direction (X-axis direction) perpendicular to the direction of peeling (positive Y-axis direction). The remaining one of the six suction portions 312 is positioned on the outer periphery of the main body 311a, in the outer periphery closest to the end point of peeling (outer periphery in the positive Y-axis direction).

[0098] The six suction portions 312 are positioned in the following order along the direction of separation (Y-axis direction): three suction portions 312, two suction portions 312, and one suction portion 312. By arranging the multiple suction portions 312 in accordance with the direction of separation, the lower wafer W1 (see FIG. 6) can be efficiently separated from the upper wafer W2 (see FIG. 6).

[0099] Of the multiple suction portions 312, the suction portion 312 located closest to the starting point of peeling (here, the negative Y-axis side) is located in a position close to the area where the blade portion 341 (see Figure 6) of the peeling inducement portion 340 (see Figure 6) described later comes into contact.

[0100] In other words, the blade portion 341 of the separation inducer 340 comes into contact with the side surface of the laminated substrate T near the suction portion 312 disposed on the negative side of the Y axis. This ensures that separation of the lower wafer W1 can be started reliably from the separation initiation site, which is the trigger for separation of the lower wafer W1 from the upper wafer W2.

[0101] In the example of FIG. 7, six suction portions 312 are provided on the elastic member 311, but the number of suction portions 312 provided on the elastic member 311 is not limited to six.

[0102] 6 , other configurations of the delamination unit 50 will be described. The second holding part 320 is located below the first holding part 310, and suction-holds the upper wafer W2 of the laminated substrate T. The second holding part 320 has a main body part 321, a support member 322, and a rotation / elevation mechanism 323.

[0103] The main body 321 has a disk shape and is made of a metal member such as aluminum. An adsorption surface 320a is provided on the upper surface of the main body 321. The adsorption surface 320a has, for example, a diameter substantially equal to that of the upper wafer W2. The adsorption surface 320a is a porous body and is made of a resin member such as PCTFE (polychlorotrifluoroethylene).

[0104] A suction space 320b communicating with the outside via the suction surface 320a is formed inside the main body 321. The suction space 320b is connected to a suction device 320d such as a vacuum pump via a suction pipe 320c.

[0105] The second holding part 320 uses the negative pressure generated by the suction of the suction device 320d to suck the non-bonding surface W2n (see FIG. 3) of the upper wafer W2 onto the suction surface 320a, thereby sucking and holding the laminated substrate T.

[0106] Furthermore, if a non-suction portion such as a groove is formed on the suction surface for the upper wafer W2, cracks may occur in the upper wafer W2 at the non-suction portion. Therefore, the suction surface 320a of the main body 321 is made flat and does not have a non-suction portion such as a groove. This makes it possible to suppress damage to the upper wafer W2.

[0107] Furthermore, by forming the suction surface 320a from a resin material such as PCTFE, damage to the upper wafer W2 can be further reduced.

[0108] The support member 322 supports the main body 321. The rotary lifting mechanism 323 rotates the support member 322 around a vertical axis, thereby rotating the main body 321. The rotary lifting mechanism 323 also moves the support member 322 in the vertical direction, thereby raising and lowering the main body 321.

[0109] The third holding part 330 is disposed above the first holding part 310, and suction-holds the non-bonding surface W1n of the lower wafer W1 after separation held by the first holding part 310. The third holding part 330 includes a main body part 331, a plurality of suction pads 332, and a lifting mechanism 333.

[0110] The main body 331 is, for example, a cylindrical member, and is inserted into the opening 311c of the elastic member 311. The main body 331 supports a plurality of suction pads 332. The plurality of suction pads 332 are provided on the lower part of the main body 331.

[0111] The lifting mechanism 333 moves the main body 331 in the vertical direction, thereby lifting and lowering the plurality of suction pads 332 supported by the main body 331 .

[0112] Specifically, the lifting mechanism 333 raises and lowers the plurality of suction pads 332 between a standby position, a suction position for suctioning the lower wafer W1 held by the first holding part 310 after separation, and a delivery position for delivering the lower wafer W1 held by the third holding part 330 to the transfer device 61 (see FIG. 1 ). The lifting mechanism 333 is fixed to, for example, an upper part of the support body 360 and is supported by the support body 360.

[0113] The third holding unit 330 can receive the lower wafer W1 after separation from the first holding unit 310 and transfer the received lower wafer W1 to the transfer device 61 stably.

[0114] The separation inducer 340 is located to the side of the second holding part 320 and forms a separation initiation site on the side surface of one end of the laminated substrate T, which serves as a trigger for separation of the lower wafer W1 from the upper wafer W2.

[0115] The peeling inducer 340 includes a blade 341, a moving mechanism 342, and an elevating mechanism 343. The blade 341 includes a sharp member 341 a and a support 341 b. The sharp member 341 a is, for example, a flat blade, and is supported by the support 341 b so that the cutting edge protrudes horizontally toward the laminated substrate T.

[0116] The movement mechanism 342 moves the blade 341 along a rail extending in the Y-axis direction. The lifting mechanism 343 is fixed to the support 360, for example, and moves the movement mechanism 342 in the vertical direction. This adjusts the height position of the blade 341, i.e., the position at which it abuts against the side surface of the laminated substrate T.

[0117] The peeling inducer 340 adjusts the height position of the blade 341 using the lifting mechanism 343, and then moves the blade 341 in the horizontal direction (here, the positive direction of the Y axis) using the moving mechanism 342.

[0118] Furthermore, the peeling inducer 340 brings the sharp member 341a of the blade portion 341 into contact with the bonded portion between the lower wafer W1 and the upper wafer W2, which is exposed on the side surface of the laminated substrate T. This forms a peeling initiation site, which serves as a trigger for peeling the lower wafer W1 from the upper wafer W2, in the laminated substrate T. Note that if the effect of reducing the bonding force by the laser light L (see FIG. 4) irradiated by the laser irradiation unit 41 (see FIG. 4) is sufficient, the peeling inducer 340 may not be provided in the peeling unit 50.

[0119] The plurality of (here, two) lifting mechanisms 350 lifts and lowers the first holding portion 310. The plurality of lifting mechanisms 350 are provided in one-to-one correspondence with the plurality of (here, two) extending portions 311b of the elastic member 311. The lifting mechanism 350 includes a support member 351, a moving mechanism 352, and a load cell 353.

[0120] The support member 351 is a member extending in the vertical direction (Z-axis direction), one end of which is connected to the extension portion 311b of the elastic member 311 (see Figure 7), and the other end of which is connected to the moving mechanism 352 via the support body 360.

[0121] The movement mechanism 352 is fixed to the upper part of the support 360 and moves the support member 351 connected to the lower part in the vertical direction. The load cell 353 detects the load applied to the support member 351.

[0122] The lifting mechanism 350 uses the moving mechanism 352 to move the support member 351 vertically upward, thereby pulling up the first holding part 310 connected to the support member 351. At this time, the lifting mechanism 350 can pull the first holding part 310 while controlling the force applied to the lower wafer W1 based on the detection result of the load cell 353.

[0123] Here, as shown in Figures 6 and 7, the support member 351 that serves as the force point for lifting, i.e., the support member 351 located on the negative side of the Y axis, is located on the opposite side of the direction in which peeling progresses than the suction portion 312 that serves as the fulcrum for lifting, i.e., the suction portion 312 that is located closest to the starting point of peeling.

[0124] Therefore, a predetermined (clockwise in FIG. 6 ) rotational force (moment) is generated on the side surface of the laminated substrate T, which is the point of action for lifting (the portion that is the starting point of peeling). This allows the lifting mechanism 350 to pull the lower wafer W1 by flipping it up from its outer edge, thereby efficiently peeling the lower wafer W1 from the upper wafer W2.

[0125] The first holding unit 310 is supported by a lifting mechanism 350, and the lifting mechanism 350 is supported by a support member 360. The support member 360 is supported by a fixing member (not shown) attached to the ceiling of the peeling unit 50.

[0126] <Details of Substrate Processing> Next, details of the substrate processing according to the embodiment will be described with reference to Fig. 8 to Fig. 17. Fig. 8 is a flowchart showing the procedure of the substrate processing according to the embodiment. Fig. 9 to Fig. 17 are views for explaining one step of the substrate processing according to the embodiment.

[0127] 8 and 9, in the substrate processing according to the embodiment, first, an oxide film Ox1 is formed on a first surface WDa of a device substrate WD on which a plurality of devices D are formed (step S101). The device substrate WD is an example of a first substrate, and the processing in step S101 is an example of a first formation step.

[0128] The device substrate WD is, for example, a single crystal silicon wafer. The devices D formed on the device substrate WD are, for example, arranged in a matrix on a first surface WDa. As shown in FIG. 9 , the device substrate WD has a second surface WDb on the opposite side of the first surface WDa.

[0129] The step of forming the oxide film Ox1 on the device substrate WD may be performed by, for example, a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method in an apparatus different from the substrate processing apparatus 1. This makes it possible to form the oxide film Ox1 with small variations in film thickness.

[0130] Note that the present disclosure is not limited to the case where the oxide film Ox1 is actively formed on the device substrate WD, and a natural oxide film that is naturally formed on the device substrate WD may be used instead of the oxide film Ox1. This makes it possible to omit the step of forming the oxide film Ox1 on the device substrate WD, and therefore the substrate processing according to the embodiment can be performed efficiently and at low cost.

[0131] In this case, the insulating layer (SiCN or TEOS film (CVD-SiO ２ Alternatively, a natural oxide film formed on the surface of the silicon dioxide film (or the like) may be used.

[0132] In the substrate processing according to the embodiment, a first support substrate WS1 shown in FIG. 10 is prepared. The first support substrate WS1 is an example of a second substrate. The first support substrate WS1 is, for example, a single crystal silicon wafer, and has approximately the same diameter as the device substrate WD. An oxide film Ox2 is formed on a first surface WS1a of the first support substrate WS1.

[0133] The step of forming the oxide film Ox2 on the first support substrate WS1 may be performed by, for example, a CVD method or a PVD method in an apparatus different from the substrate processing apparatus 1. This makes it possible to form the oxide film Ox2 with small variations in film thickness.

[0134] Furthermore, in the embodiment, the oxide film Ox2 of the first support substrate WS1 is made of the same type of oxide film as the oxide film Ox1 of the device substrate WD, thereby making it possible to increase the bonding strength.

[0135] 11 , in the substrate processing according to the embodiment, following the processing of step S101, the first surface WS1 a of the first support substrate WS1 is bonded to the first surface WDa of the device substrate WD to form the laminated substrate T (step S102). The processing of step S102 is an example of a first bonding step.

[0136] The process of step S102 is performed using the surface modification unit 30 (see FIG. 1), the surface hydrophilization unit 31 (see FIG. 1), and the bonding unit 40 (see FIG. 1) of the substrate processing apparatus 1 (see FIG. 1). As a result, the first surface WDa of the device substrate WD and the first surface WS1a of the first support substrate WS1 are bonded by siloxane bonding.

[0137] In the process of step S102, the device substrate WD is treated as, for example, the upper wafer W2 (see FIG. 3), and the first support substrate WS1 is treated as, for example, the lower wafer W1 (see FIG. 3).

[0138] In the substrate processing according to the embodiment, following the processing of step S102, the device substrate WD side of the laminated substrate T is ground to thin the device substrate WD to a desired thickness (step S103), as shown in Fig. 12. The processing of step S103 is an example of a thinning step.

[0139] The process of step S103 may be performed, for example, using an annular, rotatable grinding wheel in an apparatus other than the substrate processing apparatus 1. Furthermore, the process of step S103 may be performed, for example, using a rough grinding wheel and a finish grinding wheel in this order.

[0140] Furthermore, prior to the processing of step S103, an edge trimming process for removing the peripheral portion of the device substrate WD in the laminated substrate T may be performed in an apparatus different from the substrate processing apparatus 1. This makes it possible to prevent chipping from occurring at the peripheral portion of the device substrate WD and damage to the laminated substrate T in the processing of step S103.

[0141] In the substrate processing according to the embodiment, following the processing of step S103, an oxide film Ox3 is formed on the second surface WDc of the device substrate WD (step S104), as shown in Fig. 13. The oxide film Ox3 is an example of another oxide film, and the processing of step S104 is an example of a second formation step.

[0142] The second surface WDc of the device substrate WD is the surface opposite to the first surface WDa, and is the surface formed after the second surface WDb (see FIG. 11) of the original device substrate WD is ground.

[0143] The step of forming the oxide film Ox3 on the device substrate WD may be performed by, for example, CVD or PVD in an apparatus different from the substrate processing apparatus 1. This makes it possible to form the oxide film Ox3 with small variations in film thickness.

[0144] Note that the present disclosure is not limited to the case where the oxide film Ox3 is actively formed on the device substrate WD, and a natural oxide film that is naturally formed on the device substrate WD may be used instead of the oxide film Ox3. This allows the step of forming the oxide film Ox3 on the device substrate WD to be omitted, and therefore the substrate processing according to the embodiment can be performed efficiently and at low cost.

[0145] In the substrate processing according to the embodiment, a CMP (Chemical Mechanical Polishing) process may be performed on the second surface WDc after the process of step S104, which allows the subsequent process of step S105 to be performed satisfactorily.

[0146] In the substrate processing according to the embodiment, a second support substrate WS2 shown in FIG. 14 is prepared. The second support substrate WS2 is an example of a third substrate. The second support substrate WS2 is, for example, a single crystal silicon wafer, and has approximately the same diameter as the first support substrate WS1. An oxide film Ox4 is formed on a first surface WS2a of the second support substrate WS2.

[0147] The step of forming the oxide film Ox4 on the second support substrate WS2 may be performed by, for example, a CVD method or a PVD method in an apparatus different from the substrate processing apparatus 1. This makes it possible to form the oxide film Ox4 with small variations in film thickness.

[0148] 15 , in the substrate processing according to the embodiment, following the processing of step S104, the first surface WS2a of the second support substrate WS2 is bonded to the second surface WDc of the device substrate WD in the laminated substrate T (step S105). The processing of step S105 is an example of a second bonding step.

[0149] The process of step S105 is performed using the surface modification unit 30 (see FIG. 1), the surface hydrophilization unit 31 (see FIG. 1), and the bonding unit 40 (see FIG. 1) of the substrate processing apparatus 1 (see FIG. 1). As a result, the second surface WDc of the device substrate WD and the first surface WS2a of the second support substrate WS2 are bonded by siloxane bonding.

[0150] In the process of step S105, the laminated substrate T is treated as, for example, the lower wafer W1 (see FIG. 3). Also, in the process of step S105, the second support substrate WS2 is treated as, for example, the upper wafer W2 (see FIG. 3).

[0151] In the substrate processing according to the embodiment, following the processing of step S105, the first support substrate WS1 is peeled off from the thinned device substrate WD (step S106). The processing of step S106 is an example of a peeling process.

[0152] In the processing of step S106, first, as shown in FIG. 16, in the laser irradiation unit 41 (see FIG. 1), with the first support substrate WS1 facing upward, laser light L is irradiated onto the interface between the first support substrate WS1 and the oxide film Ox2.

[0153] Then, due to the difference in the thermal expansion coefficient between silicon and silicon oxide, a gap is formed at the interface between the first support substrate WS1 and the oxide film Ox2.

[0154] Next, in the peeling unit 50 (see FIG. 1), the blade portion 341 (see FIG. 6) is pressed against the interface between the first support substrate WS1 and the oxide film Ox2, and the first holding portion 310 (see FIG. 6) pulls the first support substrate WS1 by flipping it up from its outer edge.

[0155] As a result, the first support substrate WS1 (see FIG. 16) is peeled off from the thinned device substrate WD, as shown in Fig. 17. At this time, at least a part of the oxide film Ox2 remains on the first surface WDa of the device substrate WD.

[0156] In the substrate processing according to the embodiment, following the processing of step S106, as shown in FIG. 18, the oxide film Ox2 (see FIG. 17) is removed from the first surface WDa of the device substrate WD (step S107).

[0157] The process of step S107 may be performed by CMP processing of first surface WDa in an apparatus different from the substrate processing apparatus 1, for example.

[0158] In the substrate processing according to the embodiment, following the processing of step S107, the device substrate WD is diced to form a plurality of chips, each of which is mounted with one or more devices D (step S108). The processing of step S108 may be performed, for example, in an apparatus different from the substrate processing apparatus 1.

[0159] In the substrate processing according to the embodiment, following the processing of step S108, a plurality of chips are peeled off from the second support substrate WS2 (see FIG. 17) (step S109).

[0160] The process of step S109 may be performed after, for example, the laser irradiation unit 41 irradiates the interface between the second support substrate WS2 and the chip with laser light L. This makes it possible to easily peel the chip from the second support substrate WS2.

[0161] In the substrate processing according to the embodiment, following the processing in step S109, the plurality of chips peeled off from the second support substrate WS2 are stacked and bonded (step S110), thereby completing a series of substrate processing steps.

[0162] In the process of step S110, adjacent chips may be bonded together by siloxane bonding, which allows the chips to be firmly bonded together.

[0163] Here, in the embodiment, as described above, it is preferable that the device substrate WD and the first support substrate WS1 that supports the device substrate WD are bonded together by siloxane bonding before the device substrate WD is thinned.

[0164] This makes it possible to reduce variations in the thickness of the thinned device substrate WD, because the oxide films Ox1 and Ox2 formed for siloxane bonding can be formed thinner (for example, about 1 μm) than an adhesive, and the variations in film thickness can also be reduced compared to an adhesive.

[0165] Furthermore, in the embodiment, the variation in thickness of the thinned device substrate WD is reduced, so that the variation in thickness can be significantly reduced in a stack formed by stacking a plurality of chips.

[0166] In the embodiment, before thinning the device substrate WD, a step of forming an oxide film Ox1 on the first surface WDa of the device substrate WD may be performed by a CVD method or a PVD method, which can further reduce the variation in the thickness of the oxide film Ox1 formed for siloxane bonding.

[0167] Therefore, according to the embodiment, it is possible to further reduce variations in the thickness of the thinned device substrate WD.

[0168] In the embodiment, before thinning the device substrate WD, the step of forming the oxide film Ox2 on the first surface WS1 a of the first support substrate WS1 may be performed by the CVD method or the PVD method, which can further reduce the variation in the film thickness of the oxide film Ox2 formed for siloxane bonding.

[0169] Therefore, according to the embodiment, it is possible to further reduce variations in the thickness of the thinned device substrate WD.

[0170] Furthermore, in the embodiment, before peeling the first support substrate WS1 from the device substrate WD, the interface between the device substrate WD and the first support substrate WS1 may be irradiated with laser light L. This makes it possible to easily peel the first support substrate WS1 bonded by siloxane bonds from the device substrate WD.

[0171] In the embodiment, after the device substrate WD is thinned, the device substrate WD and the second support substrate WS2 that supports the second surface WDc side of the device substrate WD may be bonded together by siloxane bonding.

[0172] In this way, by bonding the device substrate WD and the second support substrate WS2 by siloxane bonding without the intervention of organic matter, it is possible to prevent the device substrate WD and various processing equipment from being contaminated with organic matter.

[0173] <Modifications> Next, substrate processing according to modifications of the embodiment will be described with reference to Figures 19 to 23. Note that in the following modifications, the same components as those in the embodiment will be assigned the same reference numerals, and redundant description will be omitted.

[0174] Fig. 19 is a flowchart showing a procedure for substrate processing according to a modified embodiment, and Figs. 20 to 23 are views for explaining one step of the substrate processing according to the modified embodiment.

[0175] In the substrate processing according to the modified example, first, as shown in FIG. 19, an oxide film Ox1 (see FIG. 9) is formed on a first surface WDa (see FIG. 9) of a device substrate WD (see FIG. 9) on which a plurality of devices D (see FIG. 9) are formed (step S201).

[0176] In the substrate processing of the modified example, following the processing of step S201, the first surface WS1a (see FIG. 11) of the first support substrate WS1 (see FIG. 11) is bonded to the first surface WDa of the device substrate WD to form a laminated substrate T (see FIG. 11) (step S202).

[0177] In the substrate processing according to the modified example, following the processing of step S202, the device substrate WD side of the laminated substrate T is ground to thin the device substrate WD to a desired thickness (step S203).

[0178] In the substrate processing according to the modified example, following the processing of step S203, an oxide film Ox3 (see FIG. 13) is formed on the second surface WDc (see FIG. 13) of the device substrate WD (step S204). In addition, in the substrate processing according to the modified example, a CMP processing may be performed on the second surface WDc after the processing of step S204.

[0179] The processing of steps S201 to S204 explained so far is similar to the processing of steps S101 to S104 described above, and therefore detailed explanation will be omitted.

[0180] 20 , in the substrate processing according to the modified example, following the processing of step S204, the adhesive surface Pa of the dicing tape P is attached to the second surface WDc of the device substrate WD in the laminated substrate T (step S205). The processing of step S205 is an example of an attachment step.

[0181] The dicing tape P is held, for example, by a frame-shaped frame F. The process of step S205 may be performed, for example, in an apparatus different from the substrate processing apparatus 1 (see FIG. 1).

[0182] In the substrate processing according to the modified example, following the processing of step S205, the first support substrate WS1 is peeled off from the thinned device substrate WD (step S206). The processing of step S206 is another example of a peeling process.

[0183] In the processing of step S206, first, as shown in FIG. 21, in the laser irradiation unit 41 (see FIG. 1), with the first support substrate WS1 facing upward, laser light L is irradiated onto the interface between the first support substrate WS1 and the oxide film Ox2.

[0184] Then, due to the difference in the thermal expansion coefficient between silicon and silicon oxide, a gap is formed at the interface between the first support substrate WS1 and the oxide film Ox2.

[0185] Next, in the peeling unit 50 (see FIG. 1), the blade portion 341 (see FIG. 6) is pressed against the interface between the first support substrate WS1 and the oxide film Ox2, and the first holding portion 310 (see FIG. 6) pulls the first support substrate WS1 by flipping it up from its outer edge.

[0186] As a result, the first support substrate WS1 (see FIG. 21) is peeled off from the thinned device substrate WD, as shown in Fig. 22. At this time, at least a part of the oxide film Ox2 remains on the first surface WDa of the device substrate WD.

[0187] In the substrate processing according to the modified example, following the processing in step S206, as shown in FIG. 23, the oxide film Ox2 (see FIG. 22) is removed from the first surface WDa of the device substrate WD (step S207).

[0188] The process of step S207 may be performed by CMP processing of first surface WDa in an apparatus different from the substrate processing apparatus 1, for example.

[0189] In the substrate processing according to the modified example, following the processing of step S207, the device substrate WD is diced to form a plurality of chips, each of which is mounted with one or a plurality of devices D (step S208). The processing of step S208 may be performed, for example, in an apparatus different from the substrate processing apparatus 1.

[0190] In the substrate processing according to the modified example, following the processing of step S208, a plurality of chips are peeled off from the dicing tape P (see FIG. 23) (step S209).

[0191] In the substrate processing according to the modified example, following the processing of step S209, the plurality of chips peeled off from the dicing tape P are stacked and bonded (step S210), thereby completing a series of substrate processing steps.

[0192] In the process of step S210, adjacent chips may be bonded to each other by siloxane bonding, which allows the chips to be firmly bonded to each other.

[0193] In this modification, similarly to the above-described embodiment, before the device substrate WD is thinned, the device substrate WD and the first support substrate WS1 that supports the device substrate WD may be bonded by siloxane bonding, thereby reducing variations in the thickness of the thinned device substrate WD.

[0194] Furthermore, in the modified example, the variation in thickness of the thinned device substrate WD is reduced, so that the variation in thickness can be significantly reduced in a stack formed by stacking a plurality of chips.

[0195] In a modified example, the second surface WDc side of the thinned device substrate WD may be supported by the dicing tape P. This makes it possible to easily support the second surface WDc side of the thinned device substrate WD.

[0196] The substrate processing method according to the embodiment includes a first bonding step (steps S102 and S202), a thinning step (steps S103 and S203), and a peeling step (steps S106 and S206). The first bonding step (steps S102 and S202) forms a laminated substrate T by bonding a second substrate (first support substrate WS1) to a first surface WDa of a first substrate (device substrate WD) having devices D formed on its first surface WDa. The thinning step (steps S103 and S203) grinds the first substrate (device substrate WD) side of the laminated substrate T to thin the first substrate (device substrate WD). The peeling step (steps S106 and S206) peels the second substrate (first support substrate WS1) from the thinned first substrate (device substrate WD). In the first bonding step (steps S102 and S202), the first substrate (device substrate WD) and the second substrate (first support substrate WS1) are bonded together by siloxane bonding, thereby reducing variations in the thickness of the thinned device substrate WD.

[0197] The substrate processing method according to the embodiment also includes a first forming step (steps S101 and S201). In the first forming step (steps S101 and S201), an oxide film Ox1 is formed on a first surface WDa of a first substrate (device substrate WD) before the first bonding step (steps S102 and S202). The first forming step (steps S101 and S201) is performed by a CVD method or a PVD method. This can further reduce variations in thickness of the thinned device substrate WD.

[0198] In the substrate processing method according to the embodiment, the oxide film Ox1 formed in the first formation process (steps S101 and S201) is the same type of oxide film as the oxide film Ox2 formed on the second substrate (first support substrate WS1), thereby increasing the bonding strength between the device substrate WD and the first support substrate WS1.

[0199] The substrate processing method according to the embodiment also includes a second formation process (steps S104 and S204). The second formation process (steps S104 and S204) forms another oxide film (oxide film Ox3) on a second surface WDc of the first substrate (device substrate WD) opposite to the first surface WDa, between the thinning process (steps S103 and S203) and the peeling process (steps S106 and S206). The second formation process (steps S104 and S204) is performed by a CVD method or a PVD method. This makes it possible to suppress the increase in film thickness variation of the device substrate WD.

[0200] The substrate processing method according to the embodiment also includes a second bonding step (step S105). In the second bonding step (step S105), a third substrate (second support substrate WS2) is bonded to the second surface WDc of the first substrate (device substrate WD) on which another oxide film (oxide film Ox3) has been formed between the second forming step (step S104) and the peeling step (step S106). In addition, the second bonding step (step S105) bonds the first substrate (device substrate WD) and the third substrate (second support substrate WS2) together by siloxane bonding. This makes it possible to prevent the device substrate WD and various processing equipment from being contaminated with organic matter.

[0201] The substrate processing method according to the embodiment also includes a bonding step (step S205). In the bonding step (step S205), a dicing tape P is bonded to a second surface WDc of the first substrate (device substrate WD) opposite to the first surface WDa thereof between the thinning step (step S203) and the peeling step (step S206). This allows the second surface WDc side of the thinned device substrate WD to be easily supported.

[0202] In the substrate processing method according to the embodiment, the peeling process (steps S106 and S206) involves irradiating the interface between the first substrate (device substrate WD) and the second substrate (first support substrate WS1) with infrared laser light L, and then peeling the second substrate from the thinned first substrate. This makes it possible to easily peel the first support substrate WS1 bonded by siloxane bonds from the device substrate WD.

[0203] The substrate processing apparatus 1 according to the embodiment also includes a bonding unit 40 and a peeling unit 50. The bonding unit 40 bonds a second substrate (first support substrate WS1) to a first surface WDa of a first substrate (device substrate WD) on which devices D are formed, to form a laminated substrate T. The peeling unit 50 peels the second substrate (first support substrate WS1) from the first substrate (device substrate WD) that has been thinned by grinding the first substrate (device substrate WD) side of the laminated substrate T. The bonding unit 40 also bonds the first substrate (device substrate WD) and the second substrate (first support substrate WS1) together by siloxane bonding. This reduces variations in thickness of the thinned device substrate WD.

[0204] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0205] The disclosed embodiments should be considered to be illustrative in all respects and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. The embodiments may be combined as appropriate within the scope of the appended claims.

[0206] 1 Substrate processing apparatus 30 Surface modification unit 31 Surface hydrophilization unit 40 Bonding unit 41 Laser irradiation unit 50 Peeling unit D Device L Laser light Ox1 Oxide film Ox3 Oxide film (another example of an oxide film) P Dicing tape WD Device substrate (an example of a first substrate) WDa First surface WDb, WDc Second surface WS1 First support substrate (an example of a second substrate) WS2 Second support substrate (an example of a third substrate)

Claims

1. A substrate processing method comprising: a first bonding step of bonding a second substrate to a first surface of a first substrate having a device formed on the first surface to form an overlapped substrate; a thinning step of grinding the first substrate side of the overlapped substrate to thin the first substrate; and a peeling step of peeling the second substrate from the thinned first substrate, wherein the first bonding step bonds the first substrate and the second substrate together using a siloxane bond.

2. The substrate processing method according to claim 1, further comprising a first forming step of forming an oxide film on the first surface of the first substrate before the first bonding step, wherein the first forming step is carried out by a CVD method or a PVD method.

3. The substrate processing method according to claim 2, wherein the oxide film formed in the first forming step is the same type of oxide film as the oxide film formed on the second substrate.

4. A substrate processing method according to claim 1 or 2, further comprising a second formation step, between the thinning step and the peeling step, of forming another oxide film on a second surface of the first substrate opposite to the first surface, wherein the second formation step is carried out by a CVD method or a PVD method.

5. A substrate processing method according to claim 4, further comprising a second bonding step between the second forming step and the peeling step of bonding a third substrate to the second surface of the first substrate on which the separate oxide film has been formed, wherein the second bonding step bonds the first substrate and the third substrate together by a siloxane bond.

6. The substrate processing method according to claim 1 or 2, further comprising, between the thinning step and the peeling step, a step of attaching a dicing tape to a second surface of the first substrate opposite to the first surface.

7. A substrate processing method according to claim 1 or 2, wherein the peeling step comprises irradiating an interface between the first substrate and the second substrate with infrared laser light, and then peeling the second substrate from the thinned first substrate.

8. A substrate processing apparatus comprising: a bonding unit that bonds a second substrate to a first surface of a first substrate on which a device is formed to form an overlapped substrate; and a peeling unit that peels the second substrate from the first substrate that has been thinned by grinding the first substrate side of the overlapped substrate, wherein the bonding unit bonds the first substrate and the second substrate together by siloxane bonding.

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