Substrate processing apparatus and substrate processing method

Abstract

This substrate processing device comprises: a film forming part which forms a film on a non-joining surface of a second substrate that has a joining surface joined to a first substrate that is to be thinned, and the non-joining surface opposite to the joining surface; and a control part which controls the film forming part. On the basis of the distribution of the thickness of the second substrate, the control part performs control for forming the film on a portion of the non-joining surface, or forming the film on a portion of the non-joining surface so that the film on the portion is thicker than that on other portions.

Description

[Technical Field]

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

[0002] The substrate processing system described in Patent Document 1 includes a bonding device that bonds a first substrate and a second substrate together, and a thickness reducing device that reduces the thickness of the first substrate of the laminated substrate bonded by the bonding device. The thickness reducing device is, for example, a grinding device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-103698 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a technique for reducing variations in thickness of a first substrate after thinning. [Means for solving the problem]

[0005] A substrate processing apparatus according to one embodiment of the present disclosure includes a film forming unit that forms a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface, and a control unit that controls the film forming unit. The second substrate has, on the bonding surface, a plurality of streets arranged in a rectangular lattice pattern and devices formed in device regions partitioned by the plurality of streets, and the control unit performs control to form the film in a rectangular lattice pattern along the plurality of streets when viewed from a direction perpendicular to the bonding surface, to form the film on the plurality of streets to a thickness greater than that of the device regions, to form the film in an island shape for each of the device regions, or to form the film on each of the device regions to a thickness greater than that of the plurality of streets. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, it is possible to reduce variations in the thickness of the first substrate after thinning. [Brief explanation of the drawings]

[0007] [Figure 1]1A and 1B are cross-sectional views showing a substrate processing method according to one reference embodiment, in which FIG. 1A is a cross-sectional view showing the state of the laminated substrate before thinning, FIG. 1B is a cross-sectional view showing the state of the laminated substrate during thinning, and FIG. 1C is a cross-sectional view showing the state of the laminated substrate after thinning. [Figure 2] FIG. 2 is a plan view showing the bonding surface of the first substrate and the bonding surface of the second substrate according to one reference embodiment. [Figure 3] 3A and 3B are cross-sectional views showing a substrate processing method according to one embodiment, in which FIG. 3A is a cross-sectional view showing measurement of the thickness distribution of the second substrate, FIG. 3B is a cross-sectional view showing film formation, FIG. 3C is a cross-sectional view showing thinning, and FIG. 3D is a cross-sectional view showing the state of the laminated substrate after thinning. [Figure 4] FIG. 4 is a plan view showing the non-bonding surface of the second substrate according to one embodiment. [Figure 5] Figure 5 is a cross-sectional view showing an example of forming a film using a photosensitive material, where Figure 5(A) is a cross-sectional view showing the application of the photosensitive material, Figure 5(B) is a cross-sectional view showing exposure, and Figure 5(C) is a cross-sectional view showing development. [Figure 6] Figure 6 is a cross-sectional view showing an example of forming a film using an ink material, where Figure 6(A) is a cross-sectional view showing application of the ink material using an inkjet head, and Figure 6(B) is a cross-sectional view showing application of the ink material using an ink pen. [Figure 7] FIG. 7 is a plan view showing a substrate processing apparatus according to an embodiment. [Figure 8] Figure 8 is a cross-sectional view showing a modified substrate processing method, where Figure 8(A) is a cross-sectional view showing the measurement of the thickness distribution of the second substrate, Figure 8(B) is a cross-sectional view showing the formation of a recess, Figure 8(C) is a cross-sectional view showing thinning, and Figure 8(D) is a cross-sectional view showing the state of the laminated substrate after thinning. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their description may be omitted. In this specification, the X-axis, Y-axis, and Z-axis directions are perpendicular to each other. The X-axis and Y-axis directions are horizontal directions, and the Z-axis direction is vertical.

[0009] First, a substrate processing method according to one embodiment will be described with reference to Fig. 1. First, a laminated substrate W is prepared as shown in Fig. 1(A). The laminated substrate W includes a first substrate W1 to be thinned and a second substrate W2 to be bonded to the first substrate W1. The first substrate W1 has a bonding surface W1a to be bonded to the second substrate W2 and a non-bonding surface W1b facing opposite to the bonding surface W1a. Similarly, the second substrate W2 has a bonding surface W2a to be bonded to the first substrate W1 and a non-bonding surface W2b facing opposite to the bonding surface W2a.

[0010] The first substrate W1 includes, for example, a silicon wafer, a compound semiconductor wafer, or a glass substrate. As shown in Fig. 2, the first substrate W1 has, on its bonding surface W1a, a plurality of streets S1 arranged in a rectangular lattice pattern, for example, and devices D1 formed in device regions A1 defined by the plurality of streets S1. The devices D1 include, for example, electronic circuits.

[0011] The second substrate W2 is configured similarly to the first substrate W1. That is, the second substrate W2 includes, for example, a silicon wafer, a compound semiconductor wafer, or a glass substrate. As shown in FIG. 2, the second substrate W2 has, on the bonding surface W2a of the second substrate W2, a plurality of streets S2 arranged in a rectangular lattice pattern, for example, and devices D2 formed in device regions A2 defined by the plurality of streets S2. The devices D2 include, for example, electronic circuits.

[0012] The first substrate W1 and the second substrate W2 are bonded together with the bonding surface W1a of the first substrate W1 facing the bonding surface W2a of the second substrate W2, thereby electrically connecting the device D1 of the first substrate W1 and the device D2 of the second substrate W2. After that, as shown in FIG. 1B, the first substrate W1 is thinned, and the laminated substrate W is then diced into multiple semiconductor chips. This allows for higher performance and thinner semiconductor chips.

[0013] 1A, the second substrate W2 may have a variation in thickness t2. The variation in thickness t2 is expressed, for example, as the difference between the maximum and minimum values ​​of thickness t2 (TTV: Total Thickness Variation). The variation in thickness t2 of the second substrate W2 depends on, for example, the thickness of the device D2 at the bonding surface W2a of the second substrate W2.

[0014] 1(B), the thinning device 38 thins the first substrate W1. For example, the thinning device 38 includes a substrate holding unit 381 that adsorbs the overlapped substrate W, and a grindstone driving unit 383 that applies a grindstone 382 to the overlapped substrate W from the side opposite the substrate holding unit 381. The adsorption surface of the substrate holding unit 381 has a size equal to or larger than the main surface of the overlapped substrate W, and adsorbs the entire overlapped substrate W. The substrate holding unit 381 is, for example, a vacuum chuck, and adsorbs the overlapped substrate W by vacuum adsorption.

[0015] The substrate holder 381 adsorbs the non-bonding surface W2b of the second substrate W2 so that it is flat. Therefore, if the second substrate W2 has thickness variations, minute irregularities will occur on the bonding surface W2a of the second substrate W2, and minute irregularities will also occur on the bonding surface W1a of the first substrate W1. The non-bonding surface W1b of the first substrate W1 is processed to be parallel to the non-bonding surface W2b of the second substrate W2.

[0016] 1(C), the thickness t1 of the first substrate W1 after thinning varies, which can cause problems in subsequent processes such as forming electrodes. The electrodes are formed on the non-bonding surface W1b of the first substrate W1 and are electrically connected to the device D1 formed on the bonding surface W1a of the first substrate W1.

[0017] Next, a substrate processing method according to one embodiment will be described with reference to Fig. 3. First, as shown in Fig. 3(A), a measuring device 32 measures the thickness distribution of the second substrate W2. The measurement data includes coordinates on the non-bonding surface W2b of the second substrate W2 and the thickness t2 of the second substrate W2 for each coordinate. The measuring device 32 measures the thickness distribution of the second substrate W2, for example, by using infrared light that passes through the second substrate W2 and utilizing interference between light reflected from the non-bonding surface W2b of the second substrate W2 and light reflected from the bonding surface W2a of the second substrate W2.

[0018] The measuring device 32 includes, for example, a probe 321 that irradiates infrared light perpendicularly toward the non-bonding surface W2b of the second substrate W2 and receives light reflected by the second substrate W2, a light source connected to the probe 321 via an optical fiber, a photodetector connected to the probe 321 via an optical fiber, and a movement mechanism that moves the probe 321 relative to the second substrate W2. Note that although the non-bonding surface W2b of the second substrate W2 faces downward in Fig. 3(A), it may face upward, or the overlapping substrate W may be upside down.

[0019] In this embodiment, the measuring device 32 measures the thickness distribution of the second substrate W2 after the first substrate W1 and the second substrate W2 are bonded together, but the thickness distribution of the second substrate W2 may be measured before the first substrate W1 and the second substrate W2 are bonded together. In the latter case, it is also possible to measure the thickness distribution of the second substrate W2 by using a capacitance-type displacement sensor or a laser displacement sensor to measure the distance to the bonding surface W2a of the second substrate W2. In the latter case, a contact-type sensor may also be used.

[0020] 3(B), a film F is formed on a part of the non-bonding surface W2b of the second substrate W2 based on the thickness distribution of the second substrate W2. The formation of the film F is performed under the control of a control device 90, which will be described later. The control device 90 forms the film F at a position where the thickness t2 of the second substrate W2 is at its minimum value, and does not form the film F at a position where the thickness t2 of the second substrate W2 is at its maximum value.

[0021] For example, if the thickness of the second substrate W2 at the streets S2 is smaller than the thickness of the second substrate W2 at the device region A2, the control device 90 forms the film F in a square lattice pattern along the multiple streets S2 (see FIG. 4). Note that if the thickness of the second substrate W2 at the device region A2 is smaller than the thickness of the second substrate W2 at the streets S2, the control device 90 forms the film F in an island shape for each device region A2.

[0022] The thickness of the film F is changed according to the difference (TTV) between the maximum and minimum values ​​of the thickness t2 of the second substrate W2. The larger the TTV, the larger the thickness of the film F is set to be.

[0023] In this embodiment, the film F is formed after the first substrate W1 and the second substrate W2 are bonded together, but the film F may be formed before the first substrate W1 and the second substrate W2 are bonded together.

[0024] 3(C), the thinning device 38 thins the first substrate W1 that has been previously bonded to the second substrate W2, with the film F formed on a portion of the non-bonding surface W2b of the second substrate W2. The substrate holder 381 adheres the second substrate W2 via the film F, thereby elastically deforming the second substrate W2. The second substrate W2 is elastically deformed so that a portion of the second substrate W2 enters the opening of the film F.

[0025] As a result, the bonding surface W2a of the second substrate W2 becomes flat, and the bonding surface W1a of the first substrate W1 also becomes flat. In this state, the thinning device 38 uses the grindstone 382 to process the non-bonding surface W1b of the first substrate W1 so that it is parallel to the bonding surface W1a of the first substrate W1. Therefore, as shown in FIG. 3(D), the thickness t1 of the first substrate W1 after thinning becomes uniform. Compared to the reference embodiment, this reduces variation in the thickness t1 of the first substrate W1 after thinning.

[0026] A laser processing device (not shown) may be used to thin the first substrate W1. The laser processing device forms a modified layer inside the first substrate W1. Multiple modified layers are formed at intervals in the radial and circumferential directions of the first substrate W1. The first substrate W1 can be thinned by dividing the first substrate W1 using the multiple modified layers as starting points. In this case, too, by adsorbing the second substrate W2 via the film F, the bonding surface W2a of the second substrate W2 is flattened, and the non-bonding surface W1b of the first substrate W1 is flattened. This allows the modified layer to be formed at a constant depth from the non-bonding surface W1b, reducing variation in the thickness t1 of the first substrate W1 after thinning.

[0027] Next, an example of forming a film F using a photosensitive material will be described with reference to Fig. 5. The film forming apparatus 34 includes, for example, a coating apparatus 341 shown in Fig. 5(A), an exposure apparatus 342 shown in Fig. 5(B), and a developing apparatus 343 shown in Fig. 5(C).

[0028] The coating device 341 coats the entire non-bonding surface W2b of the second substrate W2 with a photosensitive material, thereby forming a film F over the entire non-bonding surface W2b of the second substrate W2. The coating device 341 is, for example, a spin coating device, which drops the photosensitive material onto the center of the non-bonding surface W2b of the rotating second substrate W2 and spreads the photosensitive material over the entire non-bonding surface W2b by centrifugal force. The thickness of the film F can be controlled by the type of photosensitive material (e.g., material or viscosity), coating conditions (e.g., coating amount or rotation speed), or solidification conditions (e.g., drying temperature). The thickness of the film F can also be controlled by the number of times the photosensitive material is coated.

[0029] The exposure device 342 exposes a portion of the film F. The photosensitive material is a positive type in which the exposed portion disappears by development, but it may also be a negative type in which the exposed portion remains after development. The exposure device 342 exposes a portion of the film F so that, after development, the film F remains in positions where the thickness t2 of the second substrate W2 is minimum, and does not remain in positions where the thickness t2 of the second substrate W2 is maximum. The exposure device 342, for example, uses a light-shielding film having an opening pattern to expose light in a square lattice pattern along the multiple streets S2, or to expose light in an island pattern for each device region A2.

[0030] The developing device 343 develops the film F exposed by the exposure device 342. The position of the film F remaining after development is controlled by the exposure position. The developing device 343 is, for example, a spin developing device, which drops a developer onto the center of the non-bonding surface W2b of the rotating second substrate W2 and spreads the developer over the entire non-bonding surface W2b by centrifugal force. The developing device 343 may also be a spray developing device, a dip developing device, or the like.

[0031] Next, an example of forming a film F using an ink material will be described with reference to Fig. 6. The film forming device 34 includes, for example, a coating device 344 shown in Fig. 6(A) or a coating device 345 shown in Fig. 6(B).

[0032] 6(A) includes an inkjet head 3441 that ejects ink material, and a movement mechanism 3442 that moves the inkjet head 3441 relative to the second substrate W2. The position at which the film F is formed is controlled by the ejection position of the ink material. The inkjet head 3441 may have multiple nozzles, each of which may independently eject a different ink material. The viscosity of the ink material or the particle size of the particles contained in the ink material can be changed.

[0033] 6(B) includes an ink pen 3451 that applies ink material, and a movement mechanism 3452 that moves the ink pen 3451 relative to the second substrate W2. The formation position of the film F is controlled by the application position of the ink material. The application device 345 may have multiple ink pens 3451, and each ink pen 3451 may independently eject a different ink material. The viscosity of the ink material or the particle size of the particles contained in the ink material can be changed.

[0034] These applicators 344 and 345 apply ink material to a portion of the non-bonding surface W2b of the second substrate W2, thereby forming a film F on that portion of the non-bonding surface W2b of the second substrate W2. The applicators 344 and 345 form film F at positions where the thickness t2 of the second substrate W2 is at its minimum, and do not form film F at positions where the thickness t2 of the second substrate W2 is at its maximum. When using ink material, it is easier to adjust the position where film F is formed compared to when using a photosensitive material. The thickness of film F can be controlled by the amount of ink material applied, the viscosity of the ink material, or the particle size of the particles contained in the ink material. The thickness of film F can also be controlled by the number of times the ink material is applied.

[0035] The film forming apparatus 34 in the above embodiment forms the film F on a portion of the non-bonding surface W2b of the second substrate W2, but the film F may be formed on the entire non-bonding surface W2b, in which case the film F may be formed thicker on one portion of the non-bonding surface W2b than on the other portion. The film forming apparatus 34 reduces the thickness of the film F at positions where the second substrate W2 is thicker.

[0036] Next, a substrate processing apparatus 1 according to one embodiment will be described with reference to Fig. 7. The substrate processing apparatus 1 forms a film on a portion of the non-bonding surface W2b of the second substrate W2 of the overlapping substrate W, or forms a film F on a portion of the non-bonding surface W2b that is thicker than the other portion, and in this state thins the first substrate W1 of the overlapping substrate W. The first substrate W1 and the second substrate W2 are bonded together in advance, and the overlapping substrate W is loaded into the substrate processing apparatus 1. The substrate processing apparatus 1 includes a load / unload station 2, a processing station 3, and a control device 90. It is sufficient that the substrate processing apparatus 1 includes at least a film forming device 34 and a control device 90.

[0037] The loading / unloading station 2 includes a mounting table 21 on which a cassette C is placed. The cassette C accommodates a plurality of laminated substrates W spaced apart in the vertical direction. The mounting table 21 includes a plurality of mounting plates 22 arranged in a row in the Y-axis direction. A cassette C is placed on each of the plurality of mounting plates 22. The number of mounting plates 22 is not particularly limited. Similarly, the number of cassettes C is not particularly limited.

[0038] The loading / unloading station 2 has a first transfer region 23 disposed between the mounting table 21 and the processing station 3, and a first transfer device 24 that transfers the laminated substrate W in the first transfer region 23. The first transfer device 24 includes a transfer arm that holds the laminated substrate W. The transfer arm is capable of moving in the horizontal direction (both in the X-axis direction and the Y-axis direction) and the vertical direction, and of rotating about the vertical axis. Transportation The number of feed arms may be one or more.

[0039] The processing station 3 includes, for example, a first transition device 31, a measurement device 32, a first reversing device 33, a film forming device 34, a second reversing device 35, a second transition device 36, an alignment device 37, a thinning device 38, a first cleaning device 39, and a second cleaning device 40. The arrangement and number of these devices 31 to 40 are not limited to those shown in FIG.

[0040] The first transition device 31 and the second transition device 36 temporarily accommodate the overlapped substrate W. The measurement device 32 measures the thickness distribution of the second substrate W2. The first inversion device 33 and the second inversion device 35 invert the overlapped substrate W. The film formation device 34 forms a film F on a portion of the non-bonding surface W2b of the second substrate W2. The alignment device 37 detects the center of the overlapped substrate W. In addition to detecting the center of the overlapped substrate W, the alignment device 37 may also detect the crystal orientation of the first substrate W1 or the second substrate W2; specifically, it may detect a notch or orientation flat that indicates the crystal orientation of the first substrate W1 or the second substrate W2. The thinning device 38 thins the first substrate W1. The first cleaning device 39 and the second cleaning device 40 clean the overlapped substrate W.

[0041] The processing station 3 has a second transfer region 51 arranged between the first transfer region 23 and the first transition device 31, and a second transfer device 52 that transfers the laminated substrate W in the second transfer region 51. The second transfer device 52 has a configuration similar to the first transfer device 24, and transfers the laminated substrate W between multiple devices adjacent to the second transfer region 51.

[0042] The processing station 3 also has a third transfer region 53 surrounded on three sides by an alignment device 37, a thinning device 38, and a first cleaning device 39, and a third transfer device 54 that transfers the laminated substrate W in the third transfer region 53. The third transfer device 54 has a configuration similar to that of the first transfer device 24, and transfers the laminated substrate W between multiple devices adjacent to the third transfer region 53.

[0043] The control device 90 is, for example, a computer, and includes a CPU (Central Processing Unit) 91 and a storage medium 92 such as a memory. The storage medium 92 stores programs for controlling various processes executed in the substrate processing apparatus 1. The control device 90 controls the operation of the substrate processing apparatus 1 by causing the CPU 91 to execute the programs stored in the storage medium 92.

[0044] Next, a description will be given of the operation of the substrate processing apparatus 1. The following operation is performed under the control of the control device 90. First, the first transfer device 24 takes out the overlapped substrate W from the cassette C and transfers it to the first transition device 31. Next, the second transfer device 52 takes out the overlapped substrate W from the first transition device 31 and transfers it to the measurement device 32.

[0045] Next, the measuring device 32 measures the thickness distribution of the second substrate W2, as shown in FIG. 3(A). The measurement data includes coordinates on the non-bonding surface W2b of the second substrate W2 and the thickness t2 of the second substrate W2 for each coordinate. The measuring device 32 transmits the measurement data to the control device 90. The control device 90 receives the measurement data transmitted by the measuring device 32. After the measuring device 32 measures the thickness distribution of the second substrate W2, the second transport device 52 removes the overlapped substrate W from the measuring device 32 and transports it to the first reversing device 33.

[0046] Next, the first inverting device 33 inverts the overlapped substrate W upside down so that the non-bonding surface W2b of the second substrate W2 faces upward. Thereafter, the second transport device 52 removes the overlapped substrate W from the first inverting device 33 and transports it to the film forming device 34. In this embodiment, the measuring device 32 measures the thickness distribution of the second substrate W2 with the non-bonding surface W2b of the second substrate W2 facing downward, but the thickness distribution of the second substrate W2 may also be measured with the non-bonding surface W2b of the second substrate W2 facing upward. In this case, the first inverting device 33 may be omitted, and the second transport device 52 transports the overlapped substrate W removed from the measuring device 32 to the film forming device 34.

[0047] Next, the film forming apparatus 34 forms a film F on a part of the non-bonding surface W2b of the second substrate W2, as shown in Fig. 3(B). The film forming apparatus 34 forms the film F in a square lattice pattern along the plurality of streets S2 (see Fig. 2) when viewed from a direction perpendicular to the bonding surface W2a, as shown in Fig. 4. Although not shown, the film forming apparatus 34 may also form the film F in an island shape for each device region A2 when viewed from a direction perpendicular to the bonding surface W2a.

[0048] The film forming device 34 may form the film F over the entire non-bonding surface W2b of the second substrate W2. In this case, the film F may be formed thicker on one part of the non-bonding surface W2b than on the other part. When viewed from a direction perpendicular to the bonding surface W2a, the film F may be formed on multiple streets S2 to a thickness greater than that of the device region A2, or the film F may be formed on each device region to a thickness greater than that of the multiple streets S2. After the film F is formed, the second transport device 52 removes the laminated substrate W from the film forming device 34 and transports it to the second reversing device 35.

[0049] Next, the second inverting device 35 inverts the overlapped substrate W upside down so that the non-bonding surface W2b of the second substrate W2 faces downward. Thereafter, the second transfer device 52 takes out the overlapped substrate W from the second inverting device 35 and transfers it to the second transition device 36. Thereafter, the second transfer device 52 further takes out the overlapped substrate W from the second transition device 36 and transfers it to the alignment device 37.

[0050] Next, the alignment device 37 detects the center of the overlapped substrate W, for example, by detecting the outer periphery of the overlapped substrate W. The alignment device 37 may also detect the crystal orientation of the first substrate W1 or the second substrate W2, and more specifically, may also detect a notch or the like. Thereafter, the third transfer device 54 takes the overlapped substrate W out of the alignment device 37 and transfers it to the thinning device 38.

[0051] The control device 90 controls the third transfer device 54 based on the detection result of the alignment device 37, thereby controlling the alignment of the center of the substrate holding part 381 of the thinning device 38 with the center of the overlapped substrate W. Furthermore, the control device 90 controls the third transfer device 54 based on the detection result of the alignment device 37, thereby controlling the alignment of the crystal orientation of the first substrate W1 or the second substrate W2 with a desired orientation in a rotating coordinate system that rotates together with the substrate holding part 381 of the thinning device 38.

[0052] Next, the thinning device 38 thins the first substrate W1. For example, as shown in FIG. 3(C), the thinning device 38 grinds the first substrate W1 by applying a grindstone 382 to the superposed substrate W from the opposite side (e.g., the upper side) of the substrate holding unit 381 while the superposed substrate W is held by the film F. At this time, the superposed substrate W is deformed in accordance with the opening pattern of the film F or the thickness distribution of the film F. As a result, the variation in the thickness t1 of the first substrate W1 after thinning is reduced. Thereafter, the third transfer device 54 removes the superposed substrate W from the thinning device 38 and transfers it to the first cleaning device 39.

[0053] Next, the first cleaning device 39 cleans the laminated substrate W to remove particles such as processing debris. The first cleaning device 39 may remove the film F. For example, the first cleaning device 39 removes the film F by dissolving the film F in a solvent. After the laminated substrate W is dried, the second transfer device 52 removes the laminated substrate W from the first cleaning device 39 and transfers it to the second cleaning device 40.

[0054] Next, the second cleaning apparatus 40 removes processing marks by etching the laminated substrate W. After the laminated substrate W is dried, the second transfer apparatus 52 removes the laminated substrate W from the second cleaning apparatus 40 and transfers it to the measuring apparatus 32. The measuring apparatus 32 measures the thickness distribution of the first substrate W1 after thinning and transmits the measurement data to the control apparatus 90.

[0055] The control device 90 receives the measurement data sent by the measuring device 32. If the variation in the thickness t1 of the first substrate W1 after thinning is outside the allowable range, the control device 90 corrects the formation position of the film F on the non-bonding surface W2b of the second substrate W2 or the thickness distribution of the film F so that the variation in the thickness t1 of the first substrate W1 after the next thinning falls within the allowable range.

[0056] Thereafter, the second transfer device 52 takes out the overlapped substrate W from the measurement device 32 and transfers it to the first transition device 31. Subsequently, the first transfer device 24 takes out the overlapped substrate W from the first transition device 31 and stores it in the cassette C. Thereafter, the overlapped substrate W stored in the cassette C is carried out of the substrate processing apparatus 1.

[0057] Note that the first substrate W1 and the second substrate W2 are bonded in advance and the superimposed substrate W is carried into the substrate processing apparatus 1, but the first substrate W1 and the second substrate W2 may also be bonded inside the substrate processing apparatus 1. That is, the substrate processing apparatus 1 may be equipped with a bonding device, and the bonding device may bond the first substrate W1 and the second substrate W2. When the substrate processing apparatus 1 is equipped with a bonding device, the thickness distribution of the second substrate W2 may be measured before the first substrate W1 and the second substrate W2 are bonded. Furthermore, when the substrate processing apparatus 1 is equipped with a bonding device, the film F may be formed before the first substrate W1 and the second substrate W2 are bonded.

[0058] The substrate processing apparatus 1 does not necessarily have to include the measuring device 32. The measuring device 32 may be provided outside the substrate processing apparatus 1 and transmit measurement data to the control device 90. The thickness distribution of the second substrate W2 tends to be the same for each lot of the second substrate W2 (for example, for each width of the street S2, pitch of the street S2, or type of device D2). Therefore, the control device 90 may store in advance the coordinates at which the film F is formed and control the film forming device 34 in accordance with the stored data. Therefore, it is also possible not to use the measuring device 32 at all. Note that the second substrate W2 may not have the streets S2 and devices D2 formed thereon. The film F may be formed based solely on the measurement data of the measuring device 32, regardless of the positions of the streets S2 and devices D2.

[0059] Next, a substrate processing method according to a modified example will be described with reference to Fig. 8. In the above embodiment, a film F is formed on a portion of the non-bonding surface W2b of the second substrate W2 before thinning the first substrate W1, whereas in this modified example, a recess W2c is formed on a portion of the non-bonding surface W2b of the second substrate W2 before thinning the first substrate W1. Below, the differences will be mainly described.

[0060] 8(A), the measuring device 32 measures the thickness distribution of the second substrate W2. In this modification, the thickness distribution of the second substrate W2 is measured after the first substrate W1 and the second substrate W2 are bonded together, but the thickness distribution of the second substrate W2 may be measured before the first substrate W1 and the second substrate W2 are bonded together.

[0061] 8(B), a recess W2c is formed in a part of the non-bonding surface W2b of the second substrate W2 based on the thickness distribution of the second substrate W2. The formation of the recess W2c is performed under the control of the control device 90. The recess W2c is formed at the position where the thickness t2 of the second substrate W2 is at its maximum, and the recess W2c is not formed at the position where the thickness t2 of the second substrate W2 is at its minimum.

[0062] For example, if the thickness of the second substrate W2 in the device region A2 is greater than the thickness of the second substrate W2 in the streets S2, the control device 90 forms island-shaped recesses W2c for each device region A2. Note that if the thickness of the second substrate W2 in the streets S2 is greater than the thickness of the second substrate W2 in the device region A2, the control device 90 forms the recesses W2c in a square lattice pattern along the multiple streets S2.

[0063] The depth of the recess W2c is changed according to the difference between the maximum and minimum values ​​of the thickness t2 of the second substrate W2 (TTV). The greater the TTV, the greater the depth of the recess W2c is set. Note that in this modification, the recess W2c is formed after the first substrate W1 and the second substrate W2 are bonded together, but the recess W2c may also be formed before the first substrate W1 and the second substrate W2 are bonded together.

[0064] The recess W2c is formed by, for example, a laser processing device 41. The laser processing device 41 applies a laser beam to the position where the recess W2c is to be formed, thereby ablation processing the second substrate W2. The position of the recess W2c is controlled by the irradiation position of the laser beam. The depth of the recess W2c is controlled by the irradiation intensity or irradiation time of the laser beam. The laser processing device 41 is shown in FIG. 7 The film forming device 34 is installed in the substrate processing apparatus 1 .

[0065] 8(C), the thinning device 38 thins the first substrate W1 that has been previously bonded to the second substrate W2, with a recess W2c formed in part of the non-bonding surface W2b of the second substrate W2. The substrate holder 381 contacts and adsorbs the non-bonding surface W2b of the second substrate W2, thereby elastically deforming the second substrate W2 and flattening the non-bonding surface W2b of the second substrate W2.

[0066] As a result, the bonding surface W2a of the second substrate W2 is flattened, and the bonding surface W1a of the first substrate W1 is also flattened. In this state, the thinning device 38 uses the grindstone 382 to process the non-bonding surface W1b of the first substrate W1 so that it is parallel to the bonding surface W1a of the first substrate W1. Therefore, as shown in FIG. 8(D), the thickness t1 of the first substrate W1 after thinning becomes uniform. Compared to the reference embodiment, the variation in the thickness t1 of the first substrate W1 after thinning can be reduced.

[0067] A laser processing device (not shown) may be used to thin the first substrate W1. The laser processing device forms a modified layer inside the first substrate W1. Multiple modified layers are formed at intervals in the radial and circumferential directions of the first substrate W1. The first substrate W1 can be thinned by dividing the first substrate W1 using the multiple modified layers as starting points. In this case, too, by elastically deforming the second substrate W2 to flatten the bonding surface W2a of the second substrate W2 and flattening the non-bonding surface W1b of the first substrate W1, the modified layer can be formed at a constant depth from the non-bonding surface W1b, reducing variation in the thickness t1 of the first substrate W1 after thinning.

[0068] The substrate processing apparatus and substrate processing method according to the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These changes also naturally fall within the technical scope of the present disclosure.

[0069] This application claims priority based on Patent Application No. 2021-174767 filed with the Japan Patent Office on October 26, 2021, and the entire contents of Patent Application No. 2021-174767 are incorporated herein by reference. [Explanation of symbols]

[0070] 1. Substrate processing equipment 34 Film forming device (film forming section) 90 Control device (control unit) F membrane W-polymerized substrate W1 First board W2 Second board W2b Non-jointed surface

Claims

1. a film forming unit that forms a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface; a control unit that controls the film forming unit; Equipped with the second substrate has, on the bonding surface, a plurality of streets arranged in a square lattice pattern and devices formed in device regions defined by the plurality of streets; The control unit controls the substrate processing apparatus to form the film in a rectangular lattice pattern along the plurality of streets when viewed from a direction perpendicular to the bonding surface, to form the film on the plurality of streets to a thickness greater than that of the device region, to form the film in an island pattern for each device region, or to form the film on each device region to a thickness greater than that of the plurality of streets.

2. a film forming unit that forms a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface; a control unit that controls the film forming unit; Equipped with the film forming unit includes a coating unit that forms the film on the non-bonding surface of the second substrate by coating a photosensitive material on the non-bonding surface of the second substrate, an exposure unit that exposes a portion of the film, and a development unit that develops the film exposed in the exposure unit; The control unit controls the substrate processing apparatus to form the film on a portion of the non-bonding surface or to form the film on a portion of the non-bonding surface thicker than other portions based on the thickness distribution of the second substrate.

3. a film forming unit that forms a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface; a control unit that controls the film forming unit; Equipped with the film forming unit includes an application unit that applies an ink material to the non-bonding surface of the second substrate to form the film; The control unit controls the substrate processing apparatus to form the film on a portion of the non-bonding surface or to form the film on a portion of the non-bonding surface thicker than other portions based on the thickness distribution of the second substrate.

4. a film forming unit that forms a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface; a control unit that controls the film forming unit; Equipped with The control unit acquires measurement data of the thickness distribution of the second substrate and controls the substrate processing apparatus so that the film is not formed at the position where the thickness of the second substrate is at its maximum, or so that the thickness of the film is reduced at the position where the thickness of the second substrate is greater.

5. The substrate processing apparatus according to claim 4 , further comprising a measurement unit that measures a thickness distribution of the second substrate.

6. a film forming unit that forms a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface; a control unit that controls the film forming unit; Equipped with the control unit performs control to form the film on a portion of the non-bonding surface or to form the film on a portion of the non-bonding surface thicker than another portion, based on a thickness distribution of the second substrate; a thinning unit that thins the first substrate that has been previously bonded to the second substrate, while the film is formed on the non-bonding surface of the second substrate by the film forming unit.

7. The substrate processing apparatus according to claim 6 , further comprising a cleaning unit that removes the film after the first substrate is thinned by the thinning unit.

8. a thinning section for thinning the first substrate of an overlapped substrate, the thinning section including a first substrate and a second substrate bonded to the first substrate, the second substrate including a bonding surface bonded to the first substrate and a non-bonding surface facing opposite to the bonding surface; The thinned portion is a substrate holder that adsorbs the laminated substrate via a film formed on a portion of the non-bonding surface of the second substrate or a film formed on a portion of the non-bonding surface that is thicker than the other portion; a grindstone driving unit that applies a grindstone to the first substrate of the laminated substrate held by the substrate holding unit; Including, A substrate processing apparatus, wherein the film is not formed at a position where the thickness of the second substrate is at its maximum, or the film is formed so that the thickness of the film becomes smaller at positions where the thickness of the second substrate is greater.

9. 1. A substrate processing method including forming a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface, the second substrate has, on the bonding surface, a plurality of streets arranged in a square lattice pattern and devices formed in device regions defined by the plurality of streets; The substrate processing method includes forming the film in a square lattice pattern along the plurality of streets when viewed from a direction perpendicular to the bonding surface, forming the film on the plurality of streets to a thickness greater than that of the device region, forming the film in an island shape for each of the device regions, or forming the film on the plurality of device regions to a thickness greater than that of the plurality of streets.

10. 1. A substrate processing method including forming a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface, forming the film on a part of the non-bonding surface or forming the film on a part of the non-bonding surface thicker than another part based on a thickness distribution of the second substrate; A substrate processing method comprising: forming a film on the non-bonding surface of the second substrate by applying a photosensitive material to the non-bonding surface of the second substrate; exposing a portion of the film; and developing the exposed film.

11. 1. A substrate processing method including forming a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface, forming the film on a part of the non-bonding surface or forming the film on a part of the non-bonding surface thicker than another part based on a thickness distribution of the second substrate; forming the film by applying an ink material to the non-bonding surface of the second substrate.

12. 1. A substrate processing method including forming a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface, A substrate processing method including: acquiring measurement data of the thickness distribution of the second substrate; and not forming the film at a position where the thickness of the second substrate is at its maximum, or forming the film at a thickness that is smaller at a position where the thickness of the second substrate is greater.

13. 1. A substrate processing method including forming a film on a non-bonding surface of a second substrate having a bonding surface to be bonded to a first substrate to be thinned and a non-bonding surface facing opposite to the bonding surface, forming the film on a part of the non-bonding surface or forming the film on a part of the non-bonding surface thicker than another part based on a thickness distribution of the second substrate; A substrate processing method comprising: thinning the first substrate that has been bonded to the second substrate in advance, with the film formed on the non-bonding surface of the second substrate.

14. The method of claim 13 , further comprising removing the film after thinning the first substrate.

15. 1. A substrate processing method including thinning a first substrate of a laminated substrate including a first substrate and a second substrate bonded to the first substrate, the second substrate including a bonding surface bonded to the first substrate and a non-bonding surface facing opposite to the bonding surface, adsorbing the laminated substrate with a substrate holder via a film formed on a part of the non-bonding surface of the second substrate or a film formed on a part of the non-bonding surface that is thicker than the other part; grinding the first substrate of the laminated substrate held by the substrate holder with a grindstone; Including, A substrate processing method in which the film is not formed at a position where the thickness of the second substrate is at its maximum, or the film is formed so that the thickness of the film becomes smaller at positions where the thickness of the second substrate is greater.

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