Bonding method and bonding apparatus

Abstract

The bonding method of the present invention includes: a first bonding stage of bonding a first substrate and a second substrate by releasing the holding of the first substrate to form a first laminate; and a second bonding stage of bonding the thinned one of the already bonded first substrate and second substrate and a third substrate to form a second laminate. When the first substrate is thinned, the holding of the third substrate is released in the second bonding stage, and when the second substrate is thinned, the holding of the first laminate is released in the second bonding stage.

Description

Technical Field

[0001] The present invention relates to a bonding method and a bonding apparatus. Background Art

[0002] There is known a method of aligning and bonding two substrates each having a pattern such as a circuit to form a laminate (see, for example, Patent Document 1).

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-213491

[0004] In some cases, one of the two substrates to be bonded is a laminate formed by bonding a plurality of substrates. In this case, the strain generated at the stage of forming the laminate and the strain generated when the laminate is further bonded to another substrate are overlapped, resulting in an undesirable increase in the strain of the finally obtained laminate. Summary of the Invention

[0005] The bonding method according to the first aspect of the present invention includes: a first bonding stage of bonding a first substrate and a second substrate by releasing the holding of the first substrate to form a first laminate; and a second bonding stage of bonding a thinned one of the already bonded first substrate and second substrate and a third substrate to form a second laminate. When the first substrate is thinned, the holding of the third substrate is released in the second bonding stage, and when the second substrate is thinned, the holding of the first laminate is released in the second bonding stage.

[0006] The bonding method according to the second aspect of the present invention includes: a first bonding stage of bonding a first substrate and a second substrate; and a second bonding stage of bonding one of the already bonded first substrate and second substrate and a third substrate. In the second bonding stage, the one substrate and the third substrate are bonded in such a manner that the positional offset amount between the structure of the substrate that has generated strain in the first bonding stage and the structure of the third substrate is equal to or less than a specified size.

[0007] The third aspect of the present invention provides a bonding method, including: a first bonding stage of bonding a first substrate and a second substrate to form a first laminate; a second bonding stage of bonding one of the already bonded first substrate and second substrate and a third substrate to form a second laminate; and a determination stage of determining which of the first laminate and the third substrate is to be released from holding in the second bonding stage in such a manner that the positional offset amount between the structure of the substrate that has generated strain in the first bonding stage and the structure of the third substrate is equal to or less than a specified size.

[0008] The bonding method of the fourth aspect of the present invention includes: a first bonding stage of bonding a first substrate and a second substrate; and a second bonding stage of bonding one of the bonded first substrate and second substrate and a third substrate. In the second bonding stage, the one substrate and the third substrate are bonded in such a manner that the distribution of the stress generated in the third substrate in the second bonding stage is the same as the distribution of the stress generated in the one substrate in the first bonding stage.

[0009] The bonding device of the fifth aspect of the present invention includes: a bonding part that bonds a laminate and a third substrate, the laminate having a bonded first substrate and a second substrate and one of the first substrate and the second substrate being thinned; and a receiving part that receives an instruction indicating which of the laminate and the third substrate is to be released from holding during bonding. The bonding part releases the holding of one of the laminate and the third substrate based on the instruction received by the receiving part, thereby bonding the laminate and the third substrate.

[0010] The bonding device of the sixth aspect of the present invention includes: an acquisition part that acquires information for determining which of the first substrate and the second substrate is thinned when a third substrate is laminated on a first laminate formed by thinning one of the first substrate and the second substrate that have been bonded by releasing the holding of the first substrate to form a second laminate; a determination part that determines the third substrate when the first substrate is thinned and determines the first laminate when the second substrate is thinned based on the information acquired by the acquisition part; and a bonding part that releases the holding of the first laminate or the third substrate determined by the determination part and laminates the first laminate and the third substrate.

[0011] The bonding device of the seventh aspect of the present invention includes a bonding part that bonds a laminate and a third substrate, the laminate having a bonded first substrate and a second substrate and one of the first substrate and the second substrate being thinned. The bonding part releases the holding of the one of the laminate and the third substrate that is determined to be released from holding during bonding based on which of the first substrate and the second substrate is thinned, thereby bonding the laminate and the third substrate.

[0012] The bonding device of the eighth aspect of the present invention includes a bonding part that bonds a first substrate and a second substrate and bonds one of the bonded first substrate and second substrate and a third substrate. The bonding part bonds the one substrate and the third substrate in such a manner that the positional offset amount between the structure of the one substrate where strain is generated in the bonding stage of the first substrate and the second substrate and the structure of the third substrate is equal to or less than a specified size.

[0013] A ninth aspect of the present invention provides a bonding device, comprising: a bonding part that bonds a first substrate and a second substrate to form a first laminate, and bonds one of the bonded first substrate and second substrate and a third substrate to form a second laminate; and a determination part that determines which of the first laminate and the third substrate is to be released from holding when the positional offset between the structure of one of the substrates that is strained due to the bonding by the bonding part and the structure of the third substrate becomes equal to or less than a specified size.

[0014] The bonding device according to a tenth aspect of the present invention includes a bonding part that bonds a first substrate and a second substrate, and bonds one of the bonded first substrate and second substrate and a third substrate, and the bonding part bonds the one substrate and the third substrate in such a manner that the distribution of stress generated in the third substrate due to the bonding with the one substrate is the same as the distribution of stress generated in the one substrate.

[0015] The above summary of the invention does not enumerate all features of the present invention. Sub-combinations of these feature groups can also form inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic view of the substrate laminating device 100.

[0017] Figure 2 It is a schematic top view of the substrate 210.

[0018] Figure 3 It is a schematic cross-sectional view of the bonding part 300.

[0019] Figure 4 It is a flowchart showing the operation sequence of the bonding part 300.

[0020] Figure 5 It is a schematic cross-sectional view showing the operation of the bonding part 300.

[0021] Figure 6 It is a schematic cross-sectional view showing the operation of the bonding part 300.

[0022] Figure 7 It is a schematic cross-sectional view showing the operation of the bonding part 300.

[0023] Figure 8 It is a cross-sectional view of the completed laminate 240.

[0024] Figure 9 It is a flowchart showing the manufacturing sequence of the completed laminate 240.

[0025] Figure 10 It is a flowchart showing the sequence for determining the substrate 210 to be released from holding first when bonding the intermediate laminate 230 and the substrate.

[0026] Figure 11 It is a table showing options for the manufacturing order of the laminate 240.

[0027] Figure 12 It is a table showing the strain generated in each substrate when the substrates are joined according to the options.

[0028] Figure 13 It is a table showing the strain generated between the layers of the completed laminate 240 when the substrates are joined according to the options.

[0029] Figure 14 It is a diagram showing the joining process of the CIS substrate 211 and the LOGIC substrate 212.

[0030] Figure 15 It is a diagram showing the joining process of the CIS substrate 211 and the LOGIC substrate 212.

[0031] Figure 16 It is a diagram showing the joining process of the CIS substrate 211 and the LOGIC substrate 212.

[0032] Figure 17 It is a diagram showing the joining process of the CIS substrate 211 and the LOGIC substrate 212.

[0033] Figure 18 It is a cross-sectional view of the intermediate laminate 230.

[0034] Figure 19 It is a schematic diagram showing the distribution of strain in the intermediate laminate 230 during the manufacturing process.

[0035] Figure 20 It is a schematic diagram showing the distribution of strain in the intermediate laminate 230.

[0036] Figure 21 It is a diagram showing the joining process of the intermediate laminate 230 and the DRAM substrate 213.

[0037] Figure 22 It is a diagram showing the joining process of the intermediate laminate 230 and the DRAM substrate 213.

[0038] Figure 23 It is a diagram showing the joining process of the intermediate laminate 230 and the DRAM substrate 213.

[0039] Figure 24 It is a diagram showing the joining process of the intermediate laminate 230 and the DRAM substrate 213.

[0040] Figure 25 It is a cross-sectional view of the completed laminate 240.

[0041] Figure 26 It is a schematic diagram showing the distribution of non-linear strain during the manufacturing process of the completed laminate 240.

[0042] Figure 27 It is a schematic diagram showing the distribution of non-linear strain in the completed laminate 240.

[0043] Figure 28 It is a graph showing the magnification strain generated during the bonding process of Example 1.

[0044] Figure 29 It is a graph showing the magnification strain generated during the bonding process of Example 1.

[0045] Figure 30 It is a graph showing the magnification strain generated during the bonding process of Example 1.

[0046] Figure 31 It is a graph showing the magnification strain generated during the bonding process of Example 1.

[0047] Figure 32 It is a graph showing the bonding process of the CIS substrate 211 and the LOGIC substrate 212.

[0048] Figure 33 It is a graph showing the bonding process of the CIS substrate 211 and the LOGIC substrate 212.

[0049] Figure 34 It is a graph showing the bonding process of the CIS substrate 211 and the LOGIC substrate 212.

[0050] Figure 35 It is a graph showing the bonding process of the CIS substrate 211 and the LOGIC substrate 212.

[0051] Figure 36 It is a cross-sectional view of the intermediate laminate 230.

[0052] Figure 37 It is a schematic diagram showing the distribution of strain during the manufacturing process of the intermediate laminate 230.

[0053] Figure 38 It is a schematic diagram showing the distribution of strain in the intermediate laminate 230.

[0054] Figure 39 It is a graph showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0055] Figure 40 It is a graph showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0056] Figure 41It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0057] Figure 42 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0058] Figure 43 It is a cross-sectional view of the completed laminate 240.

[0059] Figure 44 It is a schematic diagram showing the distribution of non-linear strain during the manufacturing process of the completed laminate 240.

[0060] Figure 45 It is a schematic diagram showing the distribution of non-linear strain in the completed laminate 240.

[0061] Figure 46 It is a diagram showing the magnification strain generated during the bonding process of Example 2.

[0062] Figure 47 It is a diagram showing the magnification strain generated during the bonding process of Example 2.

[0063] Figure 48 It is a diagram showing the magnification strain generated during the bonding process of Example 2.

[0064] Figure 49 It is a diagram showing the magnification strain generated during the bonding process of Example 2.

[0065] Figure 50 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0066] Figure 51 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0067] Figure 52 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0068] Figure 53 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0069] Figure 54 It is a cross-sectional view of the completed laminate 240.

[0070] Figure 55 It is a schematic diagram showing the distribution of non-linear strain during the manufacturing process of the completed laminate 240.

[0071] Figure 56 It is a schematic diagram showing the distribution of non-linear strain in the completed laminate 240.

[0072] Figure 57 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 1.

[0073] Figure 58 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 1.

[0074] Figure 59 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 1.

[0075] Figure 60 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 1.

[0076] Figure 61 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0077] Figure 62 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0078] Figure 63 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0079] Figure 64 It is a diagram showing the bonding process of the intermediate laminate 230 and the DRAM substrate 213.

[0080] Figure 65 It is a cross-sectional view of the completed laminate 240.

[0081] Figure 66 It is a schematic diagram showing the distribution of non-linear strain during the manufacturing process of the completed laminate 240.

[0082] Figure 67 It is a schematic diagram showing the distribution of non-linear strain in the completed laminate 240.

[0083] Figure 68 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 2.

[0084] Figure 69 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 2.

[0085] Figure 70 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 2.

[0086] Figure 71 It is a diagram showing the magnification strain generated during the bonding process of Comparative Example 2. Detailed Description of the Invention

[0087] Hereinafter, the present invention will be described by way of embodiments of the invention. The following embodiments do not limit the invention claimed in the claims. All combinations of the features described in the embodiments are not necessarily essential for the invention.

[0088] Figure 1 It is a schematic top view of the substrate laminating apparatus 100. The substrate laminating apparatus 100 includes a housing 110, substrate cassettes 120 and 130 disposed outside the housing 110, and a control unit 150, and a conveying unit 140, a bonding unit 300, a holder storage cabinet 400, and a pre-aligner 500 disposed inside the housing 110.

[0089] The substrate cassettes 120 and 130 can be detachably attached to and detached from the housing 110 independently. One substrate cassette 120 houses the substrates 210 to be bonded later, or the first laminate, i.e., the intermediate laminate 230, formed by bonding a plurality of substrates 210. The other substrate cassette 130 houses the intermediate laminate 230, or the second laminate, i.e., the completed laminate 240, formed by bonding the substrate 210 and the intermediate laminate 230.

[0090] Here, the substrate 210 includes semiconductor wafers such as single crystal silicon wafers and compound semiconductor wafers, and also includes cases such as glass substrates and sapphire substrates other than semiconductor wafers. In addition, the intermediate laminate 230 is laminated on other substrates 210 or other intermediate laminates 230. Although the completed laminate 240 is a finished product in the lamination process, either the intermediate laminate 230 or the substrate 210 located on the surface is further thinned. In addition, the completed laminate 240 is sometimes supplied to downstream processes such as cutting, testing, and packaging.

[0091] In addition, the bonding of the substrates 210 means overlapping the main surfaces of a plurality of substrates 210 parallel to each other and fixing their relative positions by hydrogen bonds, van der Waals bonds, covalent bonds, etc. On the other hand, the overlapping of the substrates 210 means a state where the main surfaces of a plurality of substrates 210 are in contact with each other, but not necessarily a state where their relative positions are fixed. In addition, "laminating" and "overlapping" are sometimes used synonymously.

[0092] In addition, when bonding the substrates 210, the two substrates 210 are aligned with each other before bonding. In particular, the substrate 210 on which an electronic circuit or the like is formed is aligned with high precision so as to form electrical connection with the circuit of the other substrate 210 to be bonded.

[0093] The conveying unit 140 moves the individual substrate 210, the individual substrate holders 221 and 222, the intermediate laminate 230, and the completed laminate 240 inside the housing 110. Additionally, the conveying unit 140 sometimes conveys the substrate holders 221 and 222 holding the substrate 210, the intermediate laminate 230, the completed laminate 240, etc.

[0094] The control unit 150 controls the operations of the respective parts of the substrate laminating device 100 and overall controls the cooperation between the respective parts. Additionally, the control unit 150 sometimes also receives instructions from an external user and instructs the bonding unit 300 about the order in which the laminated substrates 210, etc. are to be bonded. Moreover, the control unit 150 may include a user interface such as a display unit that displays the operation state of the substrate laminating device 100 to the outside.

[0095] The bonding unit 300 has a pair of opposing stages and aligns the substrates 210, the intermediate laminate 230, etc. held on each stage with each other. Here, the term "holding" means applying a force to the substrate 210, etc. to restrict the movement of the substrate 210. Holding not only restricts the movement of the substrate 210 but sometimes also restricts deformation. Additionally, the term "release of holding" means eliminating the force applied to the substrate 210 for the purpose of holding the substrate 210.

[0096] Additionally, the bonding unit 300 forms the intermediate laminate 230 by bringing the aligned substrates 210 into contact with and bonding them to each other. Furthermore, the bonding unit 300 bonds another substrate 210 to the intermediate laminate 230 to form the completed laminate 240. For details of the bonding unit 300, refer to Figures 3 - 7 described later.

[0097] In addition, when the substrate laminating device 100 processes the substrate 210, the intermediate laminate 230, and the completed laminate 240 inside, it uses the substrate holders 221 and 222 stored in the holder storage cabinet 400. The substrate holders 221 and 222 are formed of a hard material such as alumina ceramic and have holding mechanisms such as a vacuum chuck and an electrostatic chuck. The substrate holders 221 and 222 adsorb the substrate 210, etc. using the holding mechanism, thereby protecting the thin and brittle substrate 210, the intermediate laminate 230, and the completed laminate 240 from external impacts, etc.

[0098] In addition, the substrate holders 221 and 222 adsorb the substrate 210, the intermediate laminate 230, etc., so as to maintain the shape of the substrate 210 in accordance with the shape of the holding surfaces of the substrate holders 221 and 222. Thereby, it is possible to maintain the flat state of the substrate 210, the intermediate laminate 230, etc., or to maintain the deformed state according to the shape of the holding surface. The unused substrate holders 221 and 222 are stored again in the holder storage cabinet 400 inside the substrate laminating apparatus 100, and are not taken out to the outside of the substrate laminating apparatus 100 except in cases of maintenance and replacement.

[0099] The pre-aligner 500 cooperates with the conveying unit 140 to hold the loaded substrate 210 on the substrate holders 221 and 222. In addition, the pre-aligner 500 can also be used to separate the intermediate laminate 230 carried out from the joining portion 300 from the substrate holders 221 and 222.

[0100] Figure 2 It is a schematic top view showing an example of the substrate 210. The substrate 210 has scribe lines 217, marks 218, and circuit regions 219. A plurality of marks 218 and circuit regions 219 are provided on the surface of the substrate 210, respectively.

[0101] The mark 218 is an example of a structure formed on the surface of the substrate 210. In the illustrated example, the mark 218 is overlapped and arranged on the scribe line 217 arranged between the circuit regions 219. The mark 218 uses at least a part thereof as an alignment reference when joining the substrate 210 to other substrates 210.

[0102] Each circuit region 219 includes structures such as elements, wirings, and protective films formed by photolithography technology, etc. In addition, connection portions such as pads and bumps that become connection terminals when the substrate 210 is electrically connected to other substrates 210, lead frames, etc. are also provided in the circuit region 219.

[0103] Figure 3 It is a schematic cross-sectional view showing the structure of the joining portion 300, showing the state immediately after loading two substrates 210 into the joining portion 300. The joining portion 300 includes a frame body 310, a fixed stage 321, and a movable stage 341.

[0104] The frame body 310 has a horizontal top plate 311 and a bottom plate 313, respectively. The fixed stage 321 is fixed downward to the lower surface in the figure of the top plate 311, and has a holding mechanism capable of holding the substrate holder 222 that has held the substrate 210. The substrate holder 222 held on the fixed stage 321 is loaded into the joining portion 300 with the joining surface of the substrate 210 facing downward in the figure, and is also held downward on the fixed stage 321.

[0105] In addition, in the illustrated example, the substrate holder 222 held on the fixed stage 321 has a shape in which the center of the adsorption surface for adsorbing the substrate 210 bulges. Accordingly, the substrate 210 adsorbed and held by the substrate holder 222 also follows the shape of the substrate holder 222 and is held in a state where the center bulges downward in the figure.

[0106] On the lower surface of the top plate 311 in the figure, the microscope 322 and the activation device 323 fixed downward in the figure are arranged on the side of the fixed stage 321. The microscope 322 can observe the upper surface of another substrate 210 mounted on the movable stage 341 arranged opposite to the fixed stage 321. The activation device 323 generates, for example, plasma to purify or activate the upper surface of the substrate 210 mounted on the movable stage 341.

[0107] The X-direction drive unit 331, the Y-direction drive unit 332, and the movable stage 341 are stacked and arranged on the upper surface of the bottom plate 313 of the housing 310 in the figure. On the upper surface of the movable stage 341 in the figure, the substrate holder 221 holding the substrate 210 is held. In the illustrated example, the substrate holder 221 has a flat adsorption surface, and the substrate 210 held by the substrate holder 221 is held in a flat state.

[0108] The X-direction drive unit 331 moves in the direction indicated by the arrow symbol X in the figure parallel to the bottom plate 313. The Y-direction drive unit 332 is on the X-direction drive unit 331 and moves in the direction indicated by the arrow symbol Y in the figure parallel to the bottom plate 313. By combining the operations of the X-direction drive unit 331 and the Y-direction drive unit 332, the movable stage 341 moves in a plane parallel to the bottom plate 313.

[0109] Between the Y-direction drive unit 332 and the movable stage 341, a Z-direction drive unit 333 is also arranged. The Z-direction drive unit 333 moves the movable stage 341 relative to the Y-direction drive unit 332 in the direction perpendicular to the bottom plate 313 indicated by the arrow symbol Z. Thereby, the movable stage 341 is lifted and lowered. The movement amounts of the movable stage 341 based on the X-direction drive unit 331, the Y-direction drive unit 332, and the Z-direction drive unit 333 are controlled with high precision using an interferometer or the like.

[0110] On the upper surface of the Y-direction drive unit 332 in the figure, the microscope 342 and the activation device 343 are mounted on the side of the movable stage 341. The microscope 342 moves together with the Y-direction drive unit 332 and observes the lower surface of the downward substrate 210 held on the fixed stage 321. The activation device 343 moves together with the Y-direction drive unit 332 and, like the activation device 323 described above, generates, for example, plasma irradiated onto the substrate 210 to purify or activate the lower surface of the substrate 210 held on the fixed stage 321 in the figure.

[0111] In addition, the activation of the substrate 210 includes the following cases: when the bonding surfaces of the substrate 210 come into contact with the bonding surfaces of other substrates 210, hydrogen bonds, van der Waals bonds, covalent bonds, etc. are generated, and they are bonded in a solid state without melting. The bonding surfaces of at least one of the substrates are processed. That is, activation includes easily forming bonds by generating dangling bonds on the surface of the substrate 210.

[0112] More specifically, in the activation devices 323 and 343, for example, oxygen as a processing gas is excited in a reduced-pressure atmosphere to be plasmaized, and oxygen ions are irradiated onto the surfaces of the two substrates that become the bonding surfaces. For example, when the substrate is a substrate with an SiO film formed on Si, by the irradiation of these oxygen ions, the bonds of SiO on the substrate surface that becomes the bonding surface during lamination are cut, and dangling bonds of Si and O are formed. Sometimes forming such dangling bonds on the surface of the substrate 210 is called activation.

[0113] When a substrate in a state where dangling bonds are formed is exposed to the atmosphere, for example, moisture in the air combines with the dangling bonds, and the substrate surface is covered with hydroxyl groups (OH groups). The surface of the substrate becomes a state where it is easy to combine with water molecules, that is, it becomes a state where it is easy to be hydrophilized. That is to say, as a result of activation, the surface of the substrate becomes a state where it is easy to be hydrophilized. In addition, in solid-phase bonding, the presence of impurities such as oxides and defects at the bonding interface will affect the bonding strength. Therefore, the purification of the bonding surface can also be regarded as a part of activation.

[0114] As methods for activating the substrate 210, in addition to radical irradiation based on DC plasma, RF plasma, and MW-excited plasma, sputter etching using inert gas, ion beam, high-speed atomic beam irradiation, etc. can also be exemplified. In addition, activation based on ultraviolet irradiation, ozone asher, etc. can also be exemplified. And chemical purification treatment using a liquid or gas etchant can also be exemplified.

[0115] Furthermore, a hydrophilization device (not shown) can also be used to coat pure water or the like on the surface of the substrate 210 that becomes the bonding surface to hydrophilize the surface of the substrate 210. Through this hydrophilization, the surface of the substrate 210 becomes a state where OH groups are attached, that is, a state terminated by OH groups. In addition, other activation devices instead of the activation devices 323 and 343 can be provided at positions different from the joint portion 300, and the pre-activated substrate 210 can be carried into the joint portion 300.

[0116] The joint portion 300 also includes a control unit 150. The control unit 150 controls the operations of the X-direction driving unit 331, Y-direction driving unit 332, Z-direction driving unit 333, activation device 323, and activation device 343.

[0117] In addition, before bonding the substrate 210, the control unit 150 pre-corrects the relative positions of the microscopes 322 and 342. For the correction of the microscopes 322 and 342, for example, the microscopes 322 and 342 can be focused on a common focal point F and performed by observing each other. Alternatively, a common standard index can be observed through the microscopes 322 and 342.

[0118] Figure 4 is a flowchart showing the order when performing one bonding using the bonding unit 300. In addition, Figures 5 - 7 is a schematic cross-sectional view showing the operation of the bonding unit 300 at each stage. An example in which two substrates 210 are the bonding targets will be described, but the bonding targets can also be the substrate 210 and the intermediate laminate 230. In addition, when bonding the substrates 210 to each other, substrates 210 having the same structure can be bonded to each other, or substrates having different structures can be bonded to each other.

[0119] First, the control unit 150 instructs the conveying unit 140 to carry two substrates 210 to be bonded into the bonding unit 300 (step S101). Next, as Figure 5 shown, the control unit 150 measures the position of the mark 218 on the substrate 210 using the microscopes 322, 342 and the moving stage 341 (step S102). That is, the moving stage 341 is moved to align the determined positions of the fields of view of the microscopes 322, 342 with the mark 218. Since the positions of the microscope 322 and the initial position of the microscope 342 are known, the control unit 150 can measure the absolute position of the mark 218.

[0120] Next, the control unit 150 calculates the relative positions of the substrates 210 based on the position of the mark 218 obtained in step S102 (step S103). Further, the control unit 150 calculates the amount of movement of the moving stage 341 required for aligning the substrates 210 based on the calculated relative positions of the substrates 210. The amount of movement required for alignment is calculated, for example, by a known method such as EGA (Enhanced Global Alignment) as the amount of movement of the moving stage 341 in the x direction, y direction, and the rotation angle θ. In this way, the control unit 150 is able to align the substrates 210 with the determined mark 218 as a reference.

[0121] Next, while maintaining the information on the amount of movement of the substrate 210 calculated for alignment, the control unit 150 activates the plasma scanning of the surface of the substrate 210 and activates the bonding surface of the substrate 210 by operating the activation device 323 and the activation device 343 while moving the moving stage 341 (step S104). The surface of the activated substrate 210 becomes a state where it can be bonded by contact without inclusions such as adhesives, and without processes such as welding and crimping.

[0122] Next, the control unit 150 moves the moving stage 341 based on the relative position calculated in step S103 before, and as Figure 6 shown, aligns the substrates 210 with each other (step S105). Further, the control unit 150 operates the Z-direction drive unit 333 as Figure 7 shown to raise the moving stage 341.

[0123] As a result, soon after the substrate 210 rises, a part of the substrate 210 that protrudes downward and is held by the fixed stage 321 comes into contact with a part of the substrate 210 held by the moving stage 341. In the part of the region where the substrates 210 are in contact, the substrates 210 whose surfaces have been activated in step S106 are bonded by hydrogen bonds, van der Waals bonds, and covalent bonds, etc. Further, the holding of the entire substrate 210 is released, and the bonded region is expanded by the adsorption force of the substrate 210 itself. Soon, the substrates 210 are bonded over substantially the entire surface, thereby forming an intermediate laminate 230 in which two substrates 210 are laminated and bonded (step S106).

[0124] The intermediate laminate 230 thus formed is removed from the bonding portion 300 (step S107). Further, the intermediate laminate 230 is separated from the substrate holder 221 and housed in the substrate cassette 130.

[0125] In addition, when hydrogen bonds are formed between the two substrates 210 by mutual contact, after the intermediate laminate 230 is formed, the intermediate laminate 230 can be heated by being carried into a heating device such as an annealing furnace, thereby generating covalent bonds between the substrates 210. Thereby, the bonding strength between the substrates 210 can be increased.

[0126] Next, the control unit 150 checks from the substrate cassette 120 whether there are no more substrates 210 to be bonded (step S108). If there are remaining substrates 210 to be bonded (step S108: No), the control unit 150 returns the sequence to step S101 and repeats the series of bonding sequences from steps S102 to 108. In step S108, when it is determined that there are no more substrates 210 to be bonded (step S108: Yes), the control unit 150 ends the control of the substrate laminating apparatus 100.

[0127] In addition, in the above example, the substrate holder 222 having the adsorption surface with a central bulge is held on the fixed stage 321. However, the substrate holder 222 can also be held on the moving stage 341. In addition, for the adsorption surface of the substrate holder 222 used for the purpose of bringing a part of the bonding surface of the substrate 210 into contact, in addition to the shape of the entire curved surface, it can also be a shape having local protrusions. In addition, the substrate 210 can be pushed by other components passing through the substrate holder 222 so as to locally contact the opposing substrate 210.

[0128] In addition, in the above example, two substrates 210 are joined to form the intermediate laminate 230. However, the intermediate laminate 230 and another third substrate 210 are further joined using the joint portion 300 to form the completed laminate 240.

[0129] Figure 8 It is a cross-sectional view showing a specific example of the final form of the completed laminate 240. The completed laminate 240 is a stacked image sensor having a CIS (CMOS Image Sensor) substrate 211, a LOGIC substrate 212, and a DRAM substrate 213 joined in sequence. Here, the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213 are each an example of a single substrate 210 to be stacked.

[0130] The CIS substrate 211 has a plurality of light-receiving elements arranged in a planar high density, and is a light-receiving element substrate that converts incident image light from the outside into an electrical signal and outputs it. The LOGIC substrate 212 is a processing substrate that digitally converts the electrical signal output from the CIS substrate 211 and converts it into an image signal. Further, the DRAM substrate 213 is a memory substrate that serves as a buffer, and this buffer has many memory cells, temporarily stores the image signal generated by the LOGIC substrate 212, and alleviates the speed difference between the processing speeds of the CIS substrate 211 and the LOGIC substrate 212 and the speed of the secondary storage medium for recording the image signal.

[0131] The completed laminate 240 is first formed by laminating the intermediate laminate 230 formed by the CIS substrate 211 and the LOGIC substrate 212 and the DRAM substrate 213. In addition, in the illustrated completed laminate 240, the CIS substrate 211 and the LOGIC substrate 212 are thinned and are thinner than at the time of bonding.

[0132] Figure 9 It is a flowchart showing the manufacturing sequence of the above-mentioned completed laminate 240. First, the control unit 150 acquires information about the completed laminate 240 to be manufactured first (step S201).

[0133] The information obtained here includes information for determining which layer to be thinned among the layers formed by the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213 in the process of manufacturing the laminate 240. Therefore, the control unit 150 can be said to function as an acquisition unit that acquires information for determining which layer to be thinned among the layers formed by the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213. In addition, the information obtained by the control unit 150 may also include information for determining which holding to release for bonding in the case of bonding the CIS substrate 211 and the LOGIC substrate 212 to form the intermediate laminate 230.

[0134] Next, based on the information obtained in step S201, the control unit 150 determines which holding to release in the case of bonding the intermediate laminate 230 and the DRAM substrate 213 (step S202). The determination method will be described later with reference to Figure 10 which will be described later.

[0135] Next, in the bonding portion 300, the control unit 150 bonds the CIS substrate 211 and the LOGIC substrate 212 in the order of Figure 4 (step S203). Then, an instruction is given to a thinning device such as a mechanical chemical polishing device disposed outside the substrate laminating apparatus 100 to thin the LOGIC substrate 212 (step S204). Thus, the first bonding stage in the manufacturing of the laminate 240 is completed, and the intermediate laminate 230 is formed (step S205).

[0136] Here, the control unit 150 checks from the substrate cassette 120 whether there is no longer any of the CIS substrate 211 and the LOGIC substrate 212 (step S206). When both the CIS substrate 211 and the LOGIC substrate 212 remain (step S206: No), the control unit 150 returns the order to step S203 and repeats the series of bonding orders from step S203 to 205. In step S206, when it is determined that there is no substrate 210 to be bonded (step S206: Yes), the control unit 150 ends the first bonding in the bonding portion 300 and starts the second bonding described below.

[0137] In the second bonding, the control unit 150 bonds in the order of Figure 4The intermediate laminate 230 and the DRAM substrate 213 formed by sequential bonding. First, in the bonding portion 300, the control unit 150 bonds the DRAM substrate 213 to the thinned surface of the intermediate laminate 230 formed by the CIS substrate 211 and the LOGIC substrate 212, that is, the LOGIC substrate (step S207). In this bonding, the control unit releases the holding of either the intermediate laminate 230 or the DRAM substrate 213 determined in step S202 and causes them to be bonded.

[0138] Next, the control unit 150 instructs a thinning device disposed outside the substrate laminating apparatus 100 to thin the CIS substrate 211 (step S208). Thus, the second bonding stage in the manufacture of the laminate 240 is completed, and the completed laminate 240 as a stacked image sensor is formed (step S209).

[0139] Then, the control unit 150 checks from the substrate cassette 120 whether either the intermediate laminate 230 or the DRAM substrate 213 remains (step S210). When both the intermediate laminate 230 and the DRAM substrate 213 remain (step S210: No), the control unit 150 returns the sequence to step S207 and repeats the series of bonding sequences from steps S207 to 209. In step S210, when it is determined that there is no substrate 210 to be bonded (step S210: Yes), the control unit 150 ends the second bonding in the bonding portion 300.

[0140] Figure 10 is a flowchart showing the control sequence for determining the substrate to be released from holding in step S202 above. First, based on the information acquired in step S201, the control unit 150 checks whether the sequence set for the first bonding is such that the substrate released from holding in step S203 among the CIS substrate 211 and the LOGIC substrate 212 is the substrate thinned in step S204 (step S211).

[0141] In step S211, when it is determined that the holding of the LOGIC substrate 212 is released (step S211: YES), the control unit 150 determines that the DRAM substrate 213, which is not one of the intermediate laminate 230, is the substrate whose holding is released in the second bonding (step S212). Further, in step S211, when it is determined that the holding of the LOGIC substrate 212 is not released (step S211: NO), the control unit 150 determines that the intermediate laminate 230 is the substrate whose holding is released in the second bonding (step S213). In this case, the control unit 150 can be said to function as a determining unit that determines the DRAM substrate 213 when thinning the substrate whose holding was released in the first bonding, and determines the intermediate laminate 230 when thinning the substrate whose holding was not released. The reason for determining the substrate whose holding is released first in the second bonding in such an order is described below.

[0142] In addition, in the above example, according to Figure 10 the order shown, the control unit 150 determines the substrate whose holding is released first in the second bonding. However, the control unit 150 may also receive an external designation of the side that is released first during bonding. In other words, as long as the bonding portion 300 can designate the side to be released first during bonding, even if it is not a dedicated device, the following method can be executed. In this case, the control unit 150 can be said to function as a receiving unit that receives an instruction on which of the intermediate laminate 230 and the DRAM substrate 213 has its holding released during bonding.

[0143] Figure 11 is a table showing options for the manufacturing order of the laminate 240. When manufacturing the laminate 240 using the bonding portion 300 under the control of the control unit 150, as Figure 11 shown, there are 4 combinations of the determination of the substrates whose holding is released first in the first bonding and the second bonding.

[0144] In addition, during the manufacturing process of Figure 8 the laminate 240 shown, the CIS substrate 211 is thinned after the DRAM substrate 213 is laminated on the intermediate laminate 230. By such an order, at the stage before the DRAM substrate 213 is laminated on the intermediate laminate 230, the CIS substrate 211 can be used as a support to thin the LOGIC substrate 212. Therefore, the order of attaching an additional support for thinning the LOGIC substrate 212 can be omitted. Thus, even in the combination shown in Figure 11 it is premised that the LOGIC substrate 212 is thinned in step S204 in the order shown in Figure 9 and the CIS substrate 211 is thinned in step S208 of the second bonding.

[0145] Figure 12 Indicates that when forming the completed laminate 240 in the order of the combination shown in Figure 11

[0146] In addition, the above-mentioned strain 1 and strain 2 are both strains with the strain of the substrate released from holding being positive. For strain 1 and strain 2, when joining the CIS substrate 211 and the LOGIC substrate 212, or the LOGIC substrate 212 and the DRAM substrate 213, if the strain generated on the substrate that is not released from holding and is maintained is negligibly small, it is almost equal to the strain generated on the substrate that has been released from holding. In other words, strain 1 and strain 2 are the strains remaining on the thinned substrate as a result of thinning after joining the substrate in the first joining or the second joining.

[0147] Figure 13 Furthermore, Figure 11 is a table showing the interlayer strain difference generated on the completed laminate 240 when performing joining in the combination shown in

[0148]

[0149] In addition, the above-mentioned strain corresponds to the stress distribution in each of the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213. The stress generated in the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213 deforms the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213 and displaces the structures provided on each substrate from the design coordinates, i.e., the design position, when the restraint on the substrate by the substrate holder 221, etc. is released.​​In the present embodiment, the strain that may occur in each substrate 210 including the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213 includes planar strain and three-dimensional strain. Furthermore, the planar strain on the substrate 210 may include magnification strain and orthogonal strain.

[0150] Magnification strain is a strain in which the displacement amount of a structure on the substrate 210 from the center of the substrate 210 linearly increases at a certain increase rate in the direction of a certain diameter. In the case where two substrates 210 are stacked, the magnification strains generated in the two substrates 210 are reflected in the positional deviation between the substrates 210. The value of the magnification strain is obtained by dividing the offset amount measured from the designed position at a distance r from the center of the substrate 210 by the distance r, and the unit is ppm.

[0151] In addition, the magnification strain includes a case where it is generated as an isotropic magnification strain and a case where it is generated as an anisotropic magnification strain. In the case where the magnification strain is generated as an isotropic magnification strain, the X component and the Y component of the displacement vector of the structure due to the strain are equal. Therefore, in the case where an isotropic magnification strain is generated, the change in magnification in the X direction of the substrate 210 is equal to the change in magnification in the Y direction. In the case where the magnification strain is generated as an anisotropic magnification strain, the X component and the Y component of the displacement vector from the designed position of the structure are different, and the magnification in the X direction and the magnification in the Y direction of the substrate 210 are different.

[0152] In addition, the planar strain can be classified into linear strain and non-linear strain. Linear strain is a strain that can represent the position of a structure on the substrate 210 displaced from the designed position due to strain through a linear transformation. Non-linear strain is a strain that cannot be represented by a linear transformation. Regarding the above magnification strain, the anisotropic magnification strain is classified as non-linear strain. Non-linear strain is generated, for example, by the crystal anisotropy of the substrate 210 and the processing in the manufacturing process of the substrate 210. In addition, non-linear strain sometimes occurs depending on the stiffness distribution of the configuration of the structure formed on the substrate 210.

[0153] The orthogonal strain generated as a planar strain on the substrate 210 is a strain in which, when an orthogonal coordinate X-Y with the center of the substrate as the origin is set, the structure is displaced in a direction parallel to the X axis from the designed position, and the strain increases as the structure is farther from the origin in the Y axis direction. In addition, the displacement amount of the structure due to the orthogonal strain is equal in a plurality of regions that cross the Y axis parallel to the X axis, and the absolute value of the displacement amount increases as the structure is farther from the X axis. In addition, regarding the displacement amount caused by the orthogonal strain, the direction of displacement with respect to the positive side of the Y axis and the direction of displacement with respect to the negative side of the Y axis are opposite to each other.

[0154] For the above-mentioned plane strain, the three-dimensional strain generated in the substrate 210 is a strain that causes displacement of the structure in a direction intersecting the surface of the substrate 210, and is manifested as bending of the substrate 210. Here, bending means that the whole or part of the substrate 210 is distorted. Distortion means a state in which the surface of the substrate 210 changes into a shape including points that do not exist on the plane determined by three points on the surface of the substrate 210.

[0155] In addition, bending is a strain in which the surface of the substrate 210 forms a curved surface and includes warping. Warping is a strain remaining in the substrate 210 in a state where the influence of gravity on the strain of the substrate 210 is excluded. When gravity affects warping, the strain of distortion generated on the substrate 210 is called flexure in the present embodiment. Warping includes overall warping in which the whole of the substrate 210 buckles with substantially the same curvature and local warping in which the curvature of a part of the substrate 210 changes and buckles.

[0156] The above-mentioned magnification strain can be classified into initial magnification strain, adsorption magnification strain, and bonding process magnification strain according to its generation cause.

[0157] The initial magnification strain is a strain that has already been generated in each substrate 210 from the stage before lamination, and is generated by stress generated in the process of forming marks 218, circuit regions 219, etc. on the substrate 210, periodic stiffness changes caused by arranging scribe lines 217, circuit regions 219, etc. The initial magnification strain is manifested as a state in which the position of the structure on the substrate 210 deviates from the designed position in the substrate 210. The initial magnification strain can be known before starting the lamination of the substrate 210. Information on the initial magnification strain can be obtained by measuring the substrate 210 immediately before lamination, or information measured in the manufacturing stage of the substrate 210 can be obtained in the lamination stage.

[0158] The adsorption magnification strain is a strain generated when the shape of the substrate 210 is different from the shape of the adsorption surface of the holding members such as the substrate holders 221, 223 that hold the substrate 210. If the holding member adsorbs the substrate 210 through a holding mechanism such as an electrostatic chuck or a vacuum chuck, the substrate 210 becomes a shape imitating the adsorption surface of the holding member. Therefore, when the shape of the substrate 210 is different from the shape of the adsorption surface of the holding member, the substrate 210 is adsorbed to the holding member and the substrate 210 deforms, and the state of its strain changes.

[0159] In addition, when the magnitude of the adsorption magnification strain generates strain such as warping on the substrate 210, by previously examining the relationship between the strain and the adsorption magnification strain, it can be calculated from the state of the strain including the warping amount and warping shape of the substrate 210. Therefore, it is also possible to prepare a plurality of holding members or the like having different adsorption surface shapes, and by adjusting the shape of the adsorption surface, when correcting the strain of the substrate 210, the adsorption magnification strain can be actively utilized.

[0160] The bonding process magnification strain is a magnification strain newly generated during the process of bonding by overlapping and joining the substrate 210. When bonding the substrate 210, the bonding of the substrate 210 starts from a part of the bonding surface of the substrate 210 and finally reaches substantially the entire substrate 210. Therefore, in the substrate 210 during the bonding process, deformation occurs in at least one of the substrates 210 near the boundary between the region that has already been bonded and is in close contact with the other substrate and the region that does not contact the other substrate and will be bonded later. A part of the generated deformation becomes the bonding process magnification strain by mutually bonding and fixing the substrate 210.

[0161] Among the various strains of the substrate 210 as described above, even when the substrate 210 is inverted for bonding, there are cases where the strain distribution presented by the bonding surface does not change. In addition, as in the bonding process magnification strain, depending on the bonding order, there are also cases where the distribution pattern is the same and it is possible to control which of the positive strain and the negative strain is generated.

[0162] Figures 14 - 18 It represents the case of executing Figure 11 the order of Example 1 shown in the table, and is a diagram of the non-linear strain generated in the CIS substrate 211 and the LOGIC substrate 212 during the first bonding process. As Figure 11 shown, in Example 1, during the first bonding, the holding of the LOGIC substrate 212 is released first. In Example 1, the LOGIC substrate 212 is the first substrate and the CIS substrate 211 is the second substrate.

[0163] As Figure 14 shown, at the moment of bonding after releasing the holding of the LOGIC substrate 212, the CIS substrate 211 is adsorbed by the substrate holder 221 with a flat adsorption surface and is fixed in a flat state.

[0164] Therefore, as Figure 15 shown, at the stage of bonding the CIS substrate 211 and the LOGIC substrate 212, the strain generated by the bonding occurs in the LOGIC substrate 212 that is released from holding earlier than the CIS substrate 211. Next, as Figure 16As shown, when the holding of the CIS substrate 211 by the substrate holder 221 is released, due to the stress generated in the layers of the LOGIC substrate 212, the joined CIS substrate 211 and LOGIC substrate 212 undergo warping-induced deformation, and reverse strains are generated between the CIS substrate 211 and the LOGIC substrate 212.

[0165] Then, as Figure 17 shown, the CIS substrate 211 is adsorbed onto the flat substrate holder 223 which serves as a thinning jig, and the CIS substrate 211 and the LOGIC substrate 212 are forcibly flattened. Thus, strains are respectively assigned to the joined CIS substrate 211 and LOGIC substrate 212 according to their stiffnesses. Further, as Figure 18 shown, when the holding of the substrate holder 223 on the intermediate laminate 230 formed by thinning the LOGIC substrate 212 is released, the strain of the entire intermediate laminate 230 is biased towards the layer of the LOGIC substrate 212 whose stiffness has decreased due to thinning, and the strain of the CIS substrate 211 becomes significantly smaller.

[0166] Figure 19 is a schematic top view showing the distribution of non-linear strain in the state where the joined CIS substrate 211 and LOGIC substrate 212 are held by the substrate holder 221 as shown in Figure 15 . Additionally, Figure 20 is a schematic representation of Figure 18 the top view of the distribution of non-linear strain in the intermediate laminate 230 shown. Comparing Figure 19 and Figure 20 it can be seen that a large amount of the strain generated in the LOGIC substrate 212 by the first joining is also transferred to the LOGIC substrate 212 in the intermediate laminate 230.

[0167] Figures 21 - 25 is a graph showing the non-linear strain generated in each layer of the CIS substrate 211 and the LOGIC substrate 212 and the DRAM substrate 213 in the intermediate laminate 230 during the second joining process when implementing the procedure of Example 1 shown in the table of Figure 11 . As Figure 11 shown, in Example 1, during the second joining, the holding of the DRAM substrate 213 is released first. In Example 1, the DRAM substrate 213 is the third substrate.

[0168] As Figure 21 shown, at the moment when the holding of the DRAM substrate 213 is released and joining starts, the intermediate laminate 230 is adsorbed by the substrate holder 221 with a flat adsorption surface and is fixed in a flat state. Therefore, as Figure 22As shown, at the stage of bonding the intermediate laminate 230 and the DRAM substrate 213, strain due to the bonding is generated on the DRAM substrate 213 side, but at least a part of this strain is as Figure 18 shown, a strain having the same shape as the strain of the layer of the LOGIC substrate 212 of the intermediate laminate 230. Thereby, it is possible to reduce the positional shift caused by the difference between the strain generated in the LOGIC substrate 212 and the strain generated in the DRAM substrate 213.

[0169] At this time, it is also possible to determine the bonding conditions for bonding the CIS substrate 211 and the LOGIC substrate 212 in the first bonding based on information related to the strain inferred to be generated in the DRAM substrate 213 when bonding the intermediate laminate 230 and the DRAM substrate 213 in the second bonding so that the strain generated in the DRAM substrate 213 and the strain of the layer of the LOGIC substrate 212 of the intermediate laminate 230 have the same shape as each other. Alternatively, it is also possible to determine the bonding conditions for bonding the intermediate laminate 230 and the DRAM substrate 213 in the second bonding based on information related to the strain when bonding the CIS substrate 211 and the LOGIC substrate 212 in the first bonding.

[0170] The strain generated in the LOGIC substrate 212 at the stage of forming the intermediate laminate 230 and the strain generated in the DRAM substrate 213 at the stage of bonding the intermediate laminate 230 and the DRAM substrate 213 are strains generated due to the same kind of cause, and if the directions of the strains are the same, it is possible to reduce the positional shift caused by the difference between the strain of the LOGIC substrate 212 of the intermediate laminate 230 and the strain of the DRAM substrate 213.

[0171] In the above example, at least the fitting process magnification strain generated at the stage of bonding the CIS substrate 211 and the LOGIC substrate 212 of the intermediate laminate 230 and the fitting process magnification strain generated at the stage of bonding the intermediate laminate 230 and the DRAM substrate 213 are strains having the same shape as each other. In addition, even if the strains are generated due to the same cause, in the case where strains having the same sign but different directions are generated, the difference in strain between the LOGIC substrate 212 and the DRAM substrate 213 is doubled compared to the case where no strain is generated in the DRAM substrate 213. As a result, in the completed laminate 240, the positional shift between the DRAM substrate 213 and the LOGIC substrate 212 increases.

[0172] Next, as Figure 23As shown, when the holding by the substrate holder 221 is released, due to the stress generated in the DRAM substrate 213, the entire structure including the joined intermediate laminate 230 is deformed with warping due to the action of the stress. Therefore, the intermediate laminate 230 also warps along with the DRAM substrate 213. At this time, strains opposite to those of the DRAM substrate 213 are generated in the CIS substrate 211 and the LOGIC substrate 212 forming the intermediate laminate 230.

[0173] Then, as Figure 24 shown, when the surface on the DRAM substrate 213 side is adsorbed to the substrate holder 223 as a thinning jig and the intermediate laminate 230 is forcibly flattened, the joined intermediate laminate 230 and the DRAM substrate 213 are respectively assigned strains according to their stiffnesses. Further, as Figure 25 shown, the stiffness of the thinned CIS substrate 211 is reduced. Therefore, when the holding of the completed laminate 240 by the substrate holder 223 is released, the distribution of the strain to the LOGIC substrate 212 and the CIS substrate 211 increases, and the strain of the DRAM substrate 213 decreases. In the illustrated example, the non-linear strains generated in the LOGIC substrate 212 and the DRAM substrate 213 have the same shape. Therefore, the part of the LOGIC substrate 212 corresponding to the part where the DRAM substrate 213 shrinks or expands due to release undergoes an equal amount of shrinkage or expansion deformation, and the non-linear strain of the LOGIC substrate 212 is also eliminated. On the other hand, a non-linear strain having a shape different from that of the non-linear strain generated in the DRAM substrate 213 is generated in the CIS substrate 211. Therefore, the CIS substrate 211 further deforms in the direction in which the DRAM substrate 213 shrinks or expands due to release.

[0174] Figure 26 is a schematic top view showing the distribution of non-linear strain in the state where the joined intermediate laminate 230 and the DRAM substrate 213 are held by the substrate holder 221 as Figure 22 shown. In the state Figure 26 shown, the strain generated by the first joining is generated in the LOGIC substrate 212, and the strain generated by the second joining is generated in the DRAM substrate 213.

[0175] Figure 27 is schematically showing Figure 25The top view showing the distribution of non-linear strain in the completed laminate 240 indicates the state in which the strain of the DRAM substrate 213 is distributed to the CIS substrate 211 and the DRAM substrate 213 by thinning the CIS substrate 211. At this time, strain opposite to that of the DRAM substrate 213 is distributed in the CIS substrate 211. Therefore, the strain generated during the first bonding is cancelled in the LOGIC substrate 212, and strain opposite to that of the DRAM substrate 213 is generated in the CIS substrate 211.

[0176] Figures 28 - 31 It is a diagram showing the magnification strain generated during the bonding process of Example 1. Figures 28 - 31 When the arrow symbols with hollow arrows shown have outward arrows at both ends of a straight line, it indicates that the interval between the structures on the substrate expands, and the magnification increases, that is, a magnification strain of substrate expansion deformation is generated along the radial direction of the substrate toward the outside of the substrate. In addition, in the case of showing a pair of arrow symbols with opposing arrows, it indicates that the interval between the structures on the substrate becomes narrow, and the magnification of the substrate decreases, that is, a magnification strain of substrate shrinkage deformation is generated along the radial direction of the substrate toward the center of the substrate.

[0177] When the LOGIC substrate 212 that has been previously released from holding is bonded to the CIS substrate 211 held by the substrate holder 221, a fitting process magnification strain is generated on the LOGIC substrate 212 due to the deformation generated during the fixed bonding process. The fitting process magnification strain of the LOGIC substrate 212 is a linear strain represented isotropically, as Figure 28 shown, it is a strain in which the amount of deformation linearly increases on the radial outside of the LOGIC substrate 212.

[0178] Next, when the LOGIC substrate 212 in the bonded CIS substrate 211 and LOGIC substrate 212 is thinned, the magnification strain of the LOGIC substrate 212 with reduced stiffness due to thinning hardly affects the CIS substrate 211. Therefore, in the intermediate laminate 230 formed by bonding the CIS substrate 211 and the LOGIC substrate 212, the magnification strain generated in the LOGIC substrate 212 is as Figure 29 shown and remains as it is in the LOGIC substrate 212.

[0179] Next, when the DRAM substrate 213 is bonded to the intermediate laminate 230 held by the substrate holder 221, a fitting process magnification strain is generated in the DRAM substrate 213 that has been previously released from holding. The magnification strain of the DRAM substrate 213 is the same as the magnification strain generated in the LOGIC substrate 212, and it is a strain in which the amount of deformation linearly increases on the radial outside of the DRAM substrate 213. On the LOGIC substrate 212 in contact with the DRAM substrate 213 in the intermediate laminate 230, as Figure 30As shown, the magnification strain during the bonding process has been generated. Therefore, between the bonded DRAM substrate 213 and the LOGIC substrate 212, no positional deviation caused by the magnification strain during the bonding process occurs.

[0180] Next, in the case of thinning the CIS substrate 211, as Figure 31 shown, the magnification strain of the LOGIC substrate 212 and the DRAM substrate 213 concentrates on the thinned CIS substrate 211, and the magnification strain of the LOGIC substrate 212 and the DRAM substrate 213 is substantially eliminated. However, although magnification strain in the direction opposite to the magnification strain generated in the DRAM substrate 213 is generated in the CIS substrate 211, no positional deviation occurs among the already bonded CIS substrate 211, LOGIC substrate 212, and DRAM substrate 213.

[0181] Figures 32 - 36 is a diagram showing the non - linear strain generated in the CIS substrate 211 and the LOGIC substrate 212 during the first bonding process in the case of performing the order of Example 2 shown in the table of Figure 11 As Figure 11 shown, in Example 2, in the first bonding, the holding of the CIS substrate 211 is released first. In Example 2, the CIS substrate 211 is the first substrate and the LOGIC substrate 212 is the second substrate.

[0182] As Figure 32 shown, at the moment when the holding of the CIS substrate 211 is released and bonding starts, the LOGIC substrate 212 is adsorbed to the substrate holder 221 having a flat adsorption surface and is fixed in a flat state.

[0183] Therefore, as Figure 33 shown, at the stage where the CIS substrate 211 and the LOGIC substrate 212 are bonded, strain generated by the bonding is generated in the CIS substrate 211. Next, as Figure 34 shown, in the case where the holding by the substrate holder 221 is released, due to the stress of the layer of the CIS substrate 211, the bonded CIS substrate 211 and LOGIC substrate 212 generate deformation accompanied by warping, and strains in opposite directions to each other are generated in both the CIS substrate 211 and the LOGIC substrate 212.

[0184] Then, as Figure 35 shown, the CIS substrate 211 is adsorbed to the substrate holder 223 as a thinning jig, and the CIS substrate 211 and the LOGIC substrate 212 are forced to be flattened. Thus, the bonded CIS substrate 211 and LOGIC substrate 212 are respectively assigned strain according to their stiffness. Further, as Figure 36As shown, if the substrate holder 223 releases the holding of the intermediate stack 230 formed by thinning the LOGIC substrate 212, the strain of the entire intermediate stack 230 is biased toward the layer of the LOGIC substrate 212 whose rigidity is reduced due to thinning, and the strain of the CIS substrate 211 becomes smaller.

[0185] Figure 37 For example Figure 33 2 is a schematic top view showing a state where the bonded CIS substrate 211 and the LOGIC substrate 212 are held in the substrate holder 221, and a distribution of nonlinear strain is shown. Figure 38 It is a schematic representation Figure 36 FIG. 2 is a top view of the distribution of nonlinear strain in the intermediate stack 230. Figure 37 and Figure 38 It can be seen that the strain generated in the CIS substrate 211 by the first bonding is mostly transferred to the LOGIC substrate 212 in the intermediate laminate 230 .

[0186] Figures 39 - 43 It means executing Figure 11 In the case of the sequence of Example 2 shown in the table, nonlinear strains generated in the layers of the CIS substrate 211 and the LOGIC substrate 212 in the intermediate laminate 230 and the DRAM substrate 213 during the second bonding process. Figure 11 As shown, in the second embodiment, the holding of the intermediate stack 230 is first released in the second joining.

[0187] like Figure 39 As shown, when the holding of the intermediate stack 230 is released and the bonding is started, the DRAM substrate 213 is sucked by the substrate holder 221 having a flat suction surface and fixed in a flat state. In the second embodiment, the DRAM substrate 213 is the third substrate.

[0188] Therefore, if Figure 40 As shown in FIG. 1 , at the stage of bonding the intermediate laminate 230 and the DRAM substrate 213 together, strain caused by bonding occurs in each layer of the intermediate laminate 230. Figure 41 As shown, when the holding by the substrate holder 221 is released, the stress of the intermediate stack 230 also generates strain in the opposite direction on the bonded DRAM substrate 213 , and deformation accompanied by warping occurs as a whole.

[0189] Then, if Figure 42 As shown in FIG. 1 , when the intermediate stack 230 is forcibly flattened by adsorbing the DRAM substrate 213 to the substrate holder 223 as a thinning jig, strain is distributed to the joined intermediate stack 230 and the DRAM substrate 213 according to their respective rigidities. Figure 43As shown, if the completed laminate 240 is formed by releasing the hold of the thinned CIS substrate 211 from the substrate holder 223, the distribution of strain to the LOGIC substrate 212 and the CIS substrate 211 increases, and the strain of the DRAM substrate 213 decreases.

[0190] Figure 44 is a schematic top view showing the distribution of non-linear strain in a state where the joined intermediate laminate 230 and the DRAM substrate 213 are held by the substrate holder 221 as shown. In addition, Figure 40 is a schematic top view showing the distribution of non-linear strain in the completed laminate 240 shown. Figure 45 is schematically showing Figure 43 the distribution of non-linear strain in the completed laminate 240 shown.

[0191] Comparing Figure 44 and Figure 45 it can be seen that the strain generated by the second joining cancels out the strain of the layer of the LOGIC substrate 212 remaining in the intermediate laminate 230, and the strain is generated only in the layer of the CIS substrate 211. Thus, in the final completed laminate 240, the strain also remains only in the layer of the CIS substrate 211.

[0192] Figures 46 - 49 is a graph showing the magnification strain generated during the joining process in Example 2. Figures 28 - 31 When the arrow symbol with a hollow arrow shown has outward arrows at both ends of a straight line, it indicates that the interval between the structures on the substrate expands, generating a magnification strain with an increased magnification. In addition, when a pair of arrow symbols with opposing arrows are shown, it indicates that the interval between the structures on the substrate becomes narrower, generating a magnification strain with a reduced magnification of the substrate.

[0193] When joining the CIS substrate 211 whose hold has been released to the LOGIC substrate 212 held by the substrate holder 221, as shown by the arrow symbol in Figure 46 , a fitting process magnification strain is generated in the CIS substrate 211, and the magnification of the CIS substrate 211 increases. Next, if the LOGIC substrate 212 is thinned, as shown in Figure 47 , the magnification strain generated in the CIS substrate 211 is transferred to the thinned LOGIC substrate 212 as a magnification strain that reduces the magnification. Thus, the magnification strain of the CIS substrate 211 is eliminated.

[0194] Next, when joining by releasing the hold of the intermediate laminate 230 to the DRAM substrate 213 held by the substrate holder 221, a fitting process magnification strain that increases its magnification is generated in the intermediate laminate 230. However, the LOGIC substrate 212 of the intermediate laminate 230 contains a magnification-reducing magnification strain transferred from the CIS substrate 211 during the initial joining process.

[0195] Therefore, as Figure 48 shown, the magnification strain of the LOGIC substrate 212 cancels out the fitting process magnification strain generated in the LOGIC substrate 212 during the bonding process with the DRAM substrate 213. As a result, no position shift due to magnification strain occurs between the DRAM substrate 213 and the LOGIC substrate 212 in a fixed state without generating magnification strain.

[0196] In addition, in the CIS substrate 211 where the magnification strain is temporarily eliminated, the newly generated fitting process magnification strain is retained as it is. Next, in the case of thinning the CIS substrate 211, as Figure 49 shown by the arrow symbol, although the magnification strain of the CIS substrate 211 is retained as it is, no position shift occurs between the CIS substrate 211 and the LOGIC substrate 212.

[0197] Figures 50 - 54 is a diagram showing the non-linear strain of each layer of the CIS substrate 211 and the LOGIC substrate 212 in the intermediate laminate 230 and the DRAM substrate 213 during the second bonding process when the order of Comparative Example 1 shown in the Figure 11 table is executed. As Figure 11 shown, in Comparative Example 1, the holding of the intermediate laminate 230 is released during the second bonding.

[0198] In addition, in Comparative Example 1, the first bonding is performed in the same order as in Example 1. That is, in Comparative Example 1, the LOGIC substrate 212 is the first substrate, the CIS substrate 211 is the second substrate, and the DRAM substrate 213 is the third substrate. Therefore, the state of the strain in the intermediate laminate 230 formed by the first bonding is the same as that shown in Figure 18 and Figure 20 . Therefore, all the strain generated by the first bonding is generated in the LOGIC substrate 212.

[0199] As Figure 50 shown, at the moment when the holding of the intermediate laminate 230 is released and the bonding is started, the DRAM substrate 213 is adsorbed by the substrate holder 221 with a flat adsorption surface and fixed in a flat state. Therefore, as Figure 51 shown, during the stage of bonding the intermediate laminate 230 and the DRAM substrate 213, the strain generated by the bonding is generated in each layer of the intermediate laminate 230. As a result, as Figure 12As shown, in Comparative Example 1, at the stage of bonding the intermediate laminate 230 to the fixed DRAM substrate 213, the strain generated in the LOGIC substrate 212 due to the first bonding and the strain generated in the entire intermediate laminate 230 due to the second bonding are overlapped, and the strain of the layer of the LOGIC substrate 212 in the intermediate laminate 230 is multiplied.

[0200] As Figure 52 shown, when the holding by the substrate holder 221 is released, strain is also distributed on the DRAM substrate 213. As Figure 53 shown, after adsorbing to the substrate holder 223 as a thinning jig and being forced to flatten, as Figure 54 shown, the CIS substrate 211 is thinned. If the completed laminate 240 is released from the holding by the substrate holder 223, it returns again to the state where the strain of the layer of the LOGIC substrate 212 is multiplied. Thus, when there is an error in determining the substrate for which the holding is released in the second bonding, a large strain remains in the completed laminate 240.

[0201] Figure 55 is a schematic top view showing the distribution of non-linear strain in the state where, as Figure 51 shown, with the DRAM substrate 213 fixed to the substrate holder 221, the holding of the intermediate laminate 230 is first released and the DRAM substrate 213 and the intermediate laminate 230 are laminated. Additionally, Figure 56 is a schematic representation of Figure 54 the top view of the distribution of non-linear strain in the completed laminate 240 shown. From Figure 55 and Figure 56 it can be seen that when the second bonding is performed in the order of Comparative Example 1, the strain cannot be canceled and reduced by the second bonding.

[0202] Figures 57 - 60 is a graph showing the magnification strain generated during the bonding process in Comparative Example 1. Figures 57 - 60 When the arrow symbols with hollow arrows shown as

[0203] show outward arrows at both ends of a straight line, it indicates that the interval between the structures on the substrate expands and a magnification strain with an increased magnification is generated. Additionally, when a pair of arrow symbols with opposing arrows are shown, it indicates that the interval between the structures on the substrate becomes narrower and a magnification strain with a reduced magnification of the substrate is generated. Figure 57 In the case of bonding the LOGIC substrate 212 for which the holding has been released to the CIS substrate 211 held by the substrate holder 221, as Figure 58As shown, the magnification strain generated in the LOGIC substrate 212 does not affect the CIS substrate 211, so the magnification strain of the LOGIC substrate 212 is maintained as it is.

[0204] Next, in the case of releasing the holding of the intermediate laminate 230 and bonding the DRAM substrate 213 held by the substrate holder 221, a magnification-increasing bonding process magnification strain is generated in the intermediate laminate 230. Here, the LOGIC substrate 212 in the intermediate laminate 230 already contains the magnification-increasing magnification strain generated by the initial bonding. Therefore, the bonding process magnification strains overlap, as Figure 59 shown, a deformation that further increases the magnification toward the radially outer side is generated on the LOGIC substrate 212, and a magnification strain larger than that of the CIS substrate 211 is generated.

[0205] As described above, a large magnification strain is generated on the LOGIC substrate 212. Therefore, in the completed laminate 240, a position shift due to the magnification strain is generated between the LOGIC substrate 212 and the DRAM substrate 213. The magnification strains generated in the CIS substrate 211 and the LOGIC substrate 212 are as Figure 60 shown, and are retained as they are after the CIS substrate 211 is thinned, and the position shift between the CIS substrate 211 and the LOGIC substrate 212 is not eliminated.

[0206] Figures 61 - 65 is a diagram showing the non-linear strains of each layer of the CIS substrate 211 and the LOGIC substrate 212 in the intermediate laminate 230 and the DRAM substrate 213 during the second bonding process in the case of performing the procedure of Comparative Example 2 shown in the table of Figure 11 . As Figure 11 shown, in Comparative Example 2, the holding of the DRAM substrate 213 is released during the second bonding. That is, in Comparative Example 2, the CIS substrate 211 is the first substrate, the LOGIC substrate 212 is the second substrate, and the DRAM substrate 213 is the third substrate.

[0207] As Figure 61 shown, at the moment when the holding of the DRAM substrate 213 is released and bonding is started, the intermediate laminate 230 is adsorbed by the substrate holder 221 with a flat adsorption surface and is fixed in a flat state. As Figure 62 shown, at the stage of bonding the intermediate laminate 230 and the DRAM substrate 213, a strain in the direction opposite to the strain of the LOGIC substrate 212 in the intermediate laminate 230 is generated in the DRAM substrate 213. As a result, the position shift is increased due to the difference between the strain generated in the LOGIC substrate 212 and the strain generated in the DRAM substrate 213. Furthermore, as Figure 63As shown, when the holding by the substrate holder 221 is released, due to the strain generated in the DRAM substrate 213 and opposite to the CIS substrate 211, warpage - accompanied deformation occurs in the entire bonded intermediate laminate 230 and the DRAM substrate 213.

[0208] As Figure 64 shown, when the bonded intermediate laminate 230 and the DRAM substrate 213 are adsorbed to the substrate holder 223 as a thinning jig and flattened forcibly, the bonded intermediate laminate 230 and the DRAM substrate 213 are respectively assigned strain according to their stiffness. However, as Figure 65 shown, if the completed laminate 240 formed by thinning the CIS substrate 211 is released from the holding by the substrate holder 223, the strain of the entire completed laminate 240 overlaps in the LOGIC substrate 212 and the DRAM substrate 213. Therefore, the strain of each layer of the completed laminate 240 also becomes larger.

[0209] Figure 66 is a schematic top - view showing the strain distribution in the state where the bonded intermediate laminate 230 and the DRAM substrate 213 are held by the substrate holder 221 as Figure 62 shown. In addition, Figure 67 is a schematic representation of Figure 65 the strain distribution in the completed laminate 240 shown.

[0210] Comparing Figure 66 and Figure 67 it can be seen that the strain generated by the second bonding initially occurs in the DRAM substrate 213 at the beginning of the bonding. However, in the final completed laminate 240, by thinning the CIS substrate 211, the strain of the LOGIC substrate 212 is doubled, and strain is also generated on the CIS substrate 211.

[0211] Figures 68 - 71 is a graph showing the magnification strain generated during the bonding process of Comparative Example 2. Figures 68 - 71 The arrow symbol with a hollow arrow shown, when showing outward arrows at both ends of a straight line, indicates that the interval between the structures on the substrate expands, generating a magnification strain with an increased magnification. In addition, when showing a pair of arrow symbols with opposite - facing arrows, it indicates that the interval between the structures on the substrate narrows, generating a magnification strain with a reduced magnification of the substrate.

[0212] When the CIS substrate 211 whose holding has been released is bonded to the LOGIC substrate 212 held by the substrate holder 221, as Figure 68As shown by the arrow symbol, the magnification strain during the bonding process is generated in the CIS substrate 211, and the magnification strain of the CIS substrate 211 increases. Next, if the LOGIC substrate 212 is thinned, then as Figure 69 shown, the magnification strain generated in the CIS substrate 211 is transferred to the thinned LOGIC substrate 212 as a magnification strain that reduces the magnification. Thus, the magnification strain of the CIS substrate 211 is eliminated.

[0213] Next, if, while the intermediate laminate 230 having the above-described CIS substrate 211 and LOGIC substrate 212 is held in the substrate holder 221, the holding of the DRAM substrate 213 is released and bonding is performed, a magnification strain during the bonding process that increases the magnification is generated in the DRAM substrate 213. In contrast, as described above, the LOGIC substrate 212 that is in direct contact with the DRAM substrate 213 generates a magnification strain that reduces the magnification. Therefore, as Figure 70 shown, a positional shift due to the difference in magnification strain is generated between the LOGIC substrate 212 and the DRAM substrate 213.

[0214] Next, if the CIS substrate 211 is thinned, the magnification strain generated in the DRAM substrate 213 is distributed to the thinned CIS substrate 211 and the LOGIC substrate 212. Therefore, as Figure 71 shown, the magnification strain during the bonding process generated during the secondary bonding that overlaps on the LOGIC substrate 212 becomes further larger in the direction opposite to the magnification strain generated in the DRAM substrate 213, that is, in the direction toward the center along the radial direction. In addition, a magnification strain in the direction toward the center along the radial direction is also generated on the CIS substrate 211 where the magnification strain was temporarily eliminated.

[0215] As described above, in the second bonding when manufacturing the completed laminate 240, first release the holding of the intermediate laminate 230 or the DRAM substrate 213 determined according to the Figure 10 sequence shown, so that a completed laminate 240 having at least reduced strain in the layer of the LOGIC substrate 212 and the layer of the DRAM substrate 213 can be formed. In addition, in any case, although the strain in the layer of the CIS substrate 211 remains, the strain in the layer of the CIS substrate 211 can also be reduced by the method described below.

[0216] As a first method, in the second bonding of the methods of the above-described Embodiment 1 and Embodiment 2, the crystal orientation in the direction parallel to the bonding surface on the bonding surface is inclined at an angle of, for example, 45° with respect to the crystal orientation in the direction parallel to the bonding surface of the CIS substrate 211 that is not thinned in the intermediate laminate 230, and the DRAM substrate 213 of the structure is bonded and formed in this state. Thereby, the strain caused by the stiffness distribution of the intermediate laminate 230 and the DRAM substrate 213 is offset, the strain generated by the second bonding is reduced, and finally the strain remaining in the CIS substrate 211 can be reduced.

[0217] Here, the state of the angular deviation of the plane orientation means, for example, that the state where the crystal plane orientation of the intermediate laminate 230 is the same as the crystal orientation of the DRAM substrate 213 is set to 0°, the state where the center of the intermediate laminate 230 is made to coincide with the center of the DRAM substrate 213 is maintained, and the DRAM substrate 213 is rotated around the central axis with respect to the intermediate laminate 230, and is represented by an angle. In addition, the crystal orientation of each substrate can be known based on the grooves, orientation planes, specifications, etc. of the substrate 210. Further, the crystal orientation of the substrate 210 or the intermediate laminate 230 at the time of bonding can be known from the position of the groove or the like with respect to the center of the bonding surface of the substrate 210 or the intermediate laminate 230. The rotation angle is not limited to 45°, and as long as it is in the range of 22.5° or more and 67.5° or less, the strain generated by the second bonding can be reduced as compared with the case where the crystal orientations are made the same. By bonding the DRAM substrate 213 manufactured in this way to the intermediate laminate 230, the strain caused by the distribution of the anisotropic stiffness based on the crystal orientation can be offset, and the strain generated by the bonding can be suppressed.

[0218] In addition, as a second method for reducing the strain remaining in the CIS substrate 211, after bonding the DRAM substrate 213 in the second bonding, another substrate can be bonded to the DRAM substrate 213 as a support substrate, and then the CIS substrate 211 can be thinned. Thereby, the strain generated in the DRAM substrate 213 during the second bonding is suppressed from being transferred to the CIS substrate 211 by the support substrate, and the strain distributed to the CIS substrate 211 can be reduced.

[0219] Furthermore, as a third method, after bonding the DRAM substrate 213 in the second bonding, the DRAM substrate 213 can be thinned before thinning the CIS substrate 211, and then, after bonding another support substrate to the thinned DRAM substrate 213, the CIS substrate 211 can be thinned. Thereby, most of the strain is transferred to the DRAM substrate 213, and the strain of the CIS substrate 211 can be reduced.

[0220] In addition, in the second method and the third method described above, it is preferable to use a support substrate that is less likely to generate strain. Specifically, in the second method described above, a substrate having a crystal orientation rotated, for example, 45° with respect to the crystal orientation on the bonding surface of the DRAM substrate 213 can be used on the bonding surface. In the third method described above, a substrate having a crystal orientation rotated, for example, 45° with respect to the crystal orientation on the bonding surface of the CIS substrate 211 can also be used on the bonding surface. Additionally, a circuit substrate that is another layer of the laminate, for example, a substrate connected to the DRAM substrate 213 and having a circuit for performing processing, can be used as the support substrate. Furthermore, a substrate in which the crystal orientation is inclined, for example, 45° with respect to the crystal orientation of the other can be used for either the CIS substrate 211 or the LOGIC substrate 212. The CIS substrate 211 and the LOGIC substrate 212 are bonded to form a laminate. A substrate in which the crystal orientation is inclined, for example, 45° with respect to the crystal orientation of the other can be used for either the DRAM substrate 213 or the support substrate. The DRAM substrate 213 and the support substrate are bonded to form a laminate, and the LOGIC substrate 212 and the DRAM substrate 213 are opposed to each other to bond the laminates to each other.

[0221] In addition, in this embodiment, an example is shown in which structures are respectively formed on the two substrates bonded in the first bonding. However, instead, a substrate that is not formed with a structure such as a bare silicon wafer can be used for the substrate on the side that is not released from holding during the bonding among the two substrates bonded in the first bonding. In this case, even if a positional shift occurs between the substrate on the side that is released from holding and the other substrate due to the strain generated during the bonding process, it does not pose a problem. Therefore, it is not necessary to pre-deform the substrate on the side corresponding to the strain generated in the other substrate. In this case, the bonding conditions in the first bonding can be determined based on the information related to the strain inferred to be generated in the third substrate that is related to the strain generated in the other substrate in the second bonding in such a way that the strain generated in the other substrate in the first bonding and the strain generated in the third substrate bonded to the intermediate laminate including the other substrate have the same shape. Alternatively, the bonding conditions in the second bonding can be determined based on the information related to the strain generated in the substrate on the side in the first bonding.

[0222] In addition, in the present embodiment, an example is shown in which the CIS substrate 211, the LOGIC substrate 212, and the DRAM substrate 213 are stacked in sequence. However, instead, they may be stacked in the order of the CIS substrate 211, the DRAM substrate 213, and the LOGIC substrate 212. In addition, at least two of the three or more stacked substrates may be of the same type. In this case, for example, two DRAM substrates may be joined to each other to form an intermediate laminate, and the LOGIC substrate may be stacked on the intermediate laminate. In this case, the one of the two DRAM substrates that releases the holding during joining is the first substrate, and the other becomes the second substrate, and either one of the DRAM substrates is thinned.

[0223] As described above, the present invention has been described using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is self-evident to those skilled in the art that various changes or improvements can be made to the above embodiments. From the description of the claims, it can be seen that the manner of making such changes or improvements can also be included in the technical scope of the present invention.

[0224] It should be noted that the execution order of each process such as the actions, sequences, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings can be implemented in any order as long as it is not specifically stated as "before", "in advance", etc., or as long as the output of the previous process is not used in the subsequent process. Regarding the action flow in the claims, the specification, and the drawings, even if it is described using "first", "next", etc. for convenience, it does not mean that it must be implemented in that order.

[0225] Description of Reference Numerals

[0226] 100... Substrate stacking device; 110... Housing; 120, 130... Substrate cassettes; 140... Conveyor unit; 150... Control unit; 210... Substrate; 211... CIS substrate; 212... LOGIC substrate; 213... DRAM substrate; 217... Scoring line; 218... Mark; 219... Circuit region; 221, 222, 223... Substrate holders; 230... Intermediate laminate; 240... Completed laminate; 300... Joining portion; 310... Frame; 311... Top plate; 313... Bottom plate; 321... Fixed stage; 322, 342... Microscopes; 323, 343... Activation devices; 331... X-direction drive unit; 332... Y-direction drive unit; 333... Z-direction drive unit; 341... Moving stage; 400... Holder storage cabinet; 500... Pre-aligner.

Claims

1. A bonding method, wherein, comprising: A first bonding stage, bonding the first substrate and the second substrate by releasing the holding of the first substrate, thereby forming a first laminate; A stage of thinning the bonded first substrate; and A second bonding stage, bonding the first substrate and the third substrate, which are thinned in the thinning stage, among the bonded first substrate and the second substrate, thereby forming a second laminate, releasing the holding of the third substrate among the first laminate and the third substrate in the second bonding stage.

2. A bonding method, wherein, comprising: A first bonding stage, bonding the first substrate and the second substrate by releasing the holding of the first substrate, thereby forming a first laminate; A stage of thinning the bonded second substrate; and A second bonding stage, bonding the second substrate and the third substrate, which are thinned in the thinning stage, among the bonded first substrate and the second substrate, thereby forming a second laminate, releasing the holding of the first laminate in the second bonding stage.

3. A bonding method, wherein, comprising: A first bonding stage, bonding the first substrate and the second substrate by releasing the holding of the first substrate, thereby forming a first laminate; A stage of thinning one of the bonded first substrate and the second substrate; and A second bonding stage, bonding the one substrate and the third substrate, which are thinned in the thinning stage, among the bonded first substrate and the second substrate, thereby forming a second laminate, based on information for determining which of the first substrate and the second substrate is thinned, when the first substrate is thinned, releasing the holding of the third substrate in the second bonding stage, when the second substrate is thinned, releasing the holding of the first laminate in the second bonding stage.

4. The bonding method according to any one of claims 1 to 3, wherein, the first laminate includes: a light-receiving element substrate having a plurality of light-receiving elements; and a processing substrate for processing signals generated by the light-receiving element substrate.

5. The bonding method according to claim 4, wherein, the third substrate is a memory substrate having a plurality of memory cells.

6. The bonding method according to claim 5, wherein, the crystal orientation in the direction parallel to the surface of the first substrate that is bonded to the second substrate is configured to rotate by an angle of 22.5° or more and 67.5° or less with respect to the crystal orientation in the direction parallel to the surface of the second substrate that is bonded to the first substrate.

7. The bonding method according to claim 5, wherein, further comprising: A third bonding stage of bonding a support substrate on the memory substrate of the second laminate; and A stage of thinning the light-receiving element substrate after the bonded support substrate is thinned.

8. The bonding method according to claim 7, wherein, In the case of bonding the support substrate, after forming a third region where a part of the memory substrate and a part of the support substrate are bonded, the holding of the support substrate is released to expand the third region.

9. The bonding method according to claim 5, wherein, it further includes a third bonding stage. After the memory substrate of the second laminate is thinned, a support substrate is bonded to the thinned memory substrate. In the surface where the thinned memory substrate and the support substrate are bonded, the directions of the crystal orientations parallel to this surface of the memory substrate and the support substrate are rotated 45° relative to each other.

10. The bonding method according to claim 9, wherein, the support substrate has a circuit connected to the memory substrate.

11. The bonding method according to any one of claims 1 to 10, wherein, in the first bonding stage, after forming a first bonding region by bonding a part of the first substrate and a part of the second substrate, the holding of the first substrate is released to expand the first bonding region and form the first laminate. In the second bonding stage, after bonding a part of the thinned substrate among the first substrate and the second substrate to a part of the third substrate to form a second bonding region, the holding of either the first laminate or the third substrate is released to expand the second bonding region and form the second laminate.

12. A bonding method, wherein, it includes: a first bonding stage of bonding a first substrate and a second substrate; and a second bonding stage of bonding the thinned one of the already-bonded first substrate and second substrate and a third substrate. In the second bonding stage, the one substrate and the third substrate are bonded in such a manner that the positional offset amount between the structure of the one substrate that has developed strain in the first bonding stage and the structure of the third substrate becomes equal to or less than a specified size.

13. A bonding method, wherein, it includes: a first bonding stage of bonding a first substrate and a second substrate to form a first laminate; a second bonding stage of bonding the thinned one of the already-bonded first substrate and second substrate and a third substrate to form a second laminate; and a determination stage of determining which one of the first laminate and the third substrate to release the holding of in the second bonding stage in such a manner that the positional offset amount between the structure of the one substrate that has developed strain in the first bonding stage and the structure of the third substrate becomes equal to or less than a specified size.

14. A bonding method, wherein, it includes: a first bonding stage of bonding a first substrate and a second substrate; and a second bonding stage of bonding the thinned one of the already-bonded first substrate and second substrate and a third substrate. In the second bonding stage, the one substrate and the third substrate are bonded in such a manner that the distribution of stress generated in the third substrate in the second bonding stage is the same as the distribution of stress generated in the one substrate in the first bonding stage.

15. A bonding device, wherein, it includes: a bonding part that bonds a laminate and a third substrate, the laminate having a first substrate and a second substrate that are already bonded, and one of the first substrate and the second substrate being thinned; and a receiving part that receives an instruction indicating which one of the laminate and the third substrate is to have its holding released during bonding, the bonding part releases the holding of one of the laminate and the third substrate based on the instruction received by the receiving part, thereby bonding the laminate and the third substrate.

16. A bonding device, wherein, it includes: a first holding part that holds a laminate formed by thinning the first substrate among the first substrate and the second substrate that are bonded by releasing the holding of the first substrate; and a second holding part that holds a third substrate bonded to the first substrate of the laminate, when the third substrate is laminated on the laminate, the holding of the third substrate by the second holding part among the holding of the laminate by the first holding part and the holding of the third substrate by the second holding part is released.

17. A bonding device, wherein, it includes: a first holding part that holds a laminate formed by thinning the second substrate among the first substrate and the second substrate that are bonded by releasing the holding of the first substrate; and a second holding part that holds a third substrate bonded to the second substrate of the laminate, when the third substrate is laminated on the laminate, the holding of the laminate by the first holding part among the holding of the laminate by the first holding part and the holding of the third substrate by the second holding part is released.

18. A bonding device, wherein, it includes: an acquisition part that, when a second laminate is formed by laminating a third substrate on a first laminate formed by thinning one of the first substrate and the second substrate that are bonded by releasing the holding of the first substrate, acquires information for determining which one of the first substrate and the second substrate is thinned; a determination part that, based on the information acquired by the acquisition part, determines the third substrate when the first substrate is thinned, and determines the first laminate when the second substrate is thinned; and a bonding part that releases the holding of the first laminate or the third substrate determined by the determination part, and laminates the first laminate and the third substrate.

19. A bonding device, wherein, it includes a bonding part that bonds a laminate and a third substrate, the laminate having a first substrate and a second substrate that are already bonded, and one of the first substrate and the second substrate being thinned, The joint releases the holding of the one determined to release the holding during bonding between the laminate and the third substrate based on which of the first substrate and the second substrate is thinned, thereby bonding the laminate and the third substrate.

20. A bonding device, wherein, it includes a joint that bonds a first substrate and a second substrate, and bonds the thinned substrate of the bonded first substrate and second substrate and a third substrate, the joint bonds the one substrate and the third substrate in such a manner that the positional offset between the structure of the one substrate strained due to bonding and the structure of the third substrate is equal to or less than a specified magnitude.

21. A bonding device, wherein, it includes: a joint that bonds a first substrate and a second substrate to form a first laminate, and bonds the thinned substrate of the bonded first substrate and second substrate and a third substrate to form a second laminate; and a determination unit that determines which of the first laminate and the third substrate is to have its holding released when bonding the one substrate and the third substrate in such a manner that the positional offset between the structure of the one substrate strained due to bonding by the joint and the structure of the third substrate is equal to or less than a specified magnitude.

22. A bonding device, wherein, it includes a joint that bonds a first substrate and a second substrate, and bonds the thinned substrate of the bonded first substrate and second substrate and a third substrate, the joint bonds the one substrate and the third substrate in such a manner that the stress distribution generated in the third substrate due to bonding with the one substrate is the same as the stress distribution generated in the one substrate.

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