Substrate bonding device, calculation device, substrate bonding method and calculation method

Abstract

The present invention relates to a substrate bonding device, a calculation device, a substrate bonding method and a calculation method. The substrate bonding device comprises: a first holding portion that holds a first substrate; and a second holding portion that holds a second substrate, an initial bonding area is formed between a portion of the first substrate and a portion of the second substrate, and the first substrate and the second substrate are bonded by releasing the second substrate having the initial bonding area formed thereon from the second holding portion, and the initial bonding area is set based on information related to deformation of the second substrate.

Description

Technical Field

[0001] The invention relates to a substrate laminating device, a calculating device, a substrate laminating method and a calculating method. Background Art

[0002] There is known a substrate bonding method in which a pair of substrates is bonded while one of the pair of substrates is held and the other substrate is released from the holding state to be released toward the one substrate (for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2015-95579

[0004] In the above method, regardless of the curvature of one substrate released during bonding, the center portion is pressed under the same conditions to deform into a convex shape, so that the center portion abuts against the center portion of the other substrate, and the bonded area is gradually expanded toward the peripheral direction. Therefore, depending on the curvature of one substrate to be bonded, the positional offset amount generated between the two bonded substrates may vary greatly. Summary of the invention

[0005] In one embodiment of the present invention, a substrate bonding device is provided, comprising: a first holding portion, which holds a first substrate; and a second holding portion, which holds a second substrate, wherein an initial bonding area is formed between a portion of the first substrate and a portion of the second substrate, and the first substrate and the second substrate are bonded by releasing the second substrate having the initial bonding area formed thereon from the second holding portion, wherein the initial bonding area is set based on information related to deformation of the second substrate.

[0006] In one embodiment of the present invention, there is provided a computing device for calculating parameters used when a first substrate and a second substrate deformed into a convex shape are brought into contact with each other while being held separately and the first substrate and the second substrate are bonded together by releasing the holding of the second substrate, wherein at least one of the amount of convexity for deforming the second substrate into a convex shape, the adsorption area of ​​the outer peripheral portion of the second substrate for holding the second substrate, and the timing for releasing the holding of the second substrate is calculated based on information related to the deformation of the second substrate.

[0007] In one embodiment of the present invention, a substrate bonding device is provided, comprising: a first holding portion, which holds a first substrate; and a second holding portion, which holds the second substrate, wherein an initial bonding area is formed after a portion of the first substrate is brought into contact with a portion of the second substrate, and the first substrate and the second substrate are bonded by releasing the second substrate having the initial bonding area formed thereon from the second holding portion, wherein the initial bonding area is a size in which the positional offset between the first substrate and the second substrate after bonding is below a threshold value.

[0008] In one embodiment of the present invention, a substrate bonding device is provided, comprising: a first holding portion, which holds a first substrate; and a second holding portion, which holds a second substrate, and forms an initial bonding area between a portion of the first substrate and a portion of the second substrate, and the first substrate and the second substrate are bonded by releasing the second substrate with the initial bonding area formed from the second holding portion. The substrate bonding device also comprises a judging portion, which judges whether the initial bonding area is formed, and when the judging portion judges that the initial bonding area is formed, the second holding portion releases the second substrate.

[0009] In one embodiment of the present invention, a substrate bonding method is provided, comprising: a stage of holding a first substrate on a first holding portion; a stage of holding a second substrate on a second holding portion; a stage of forming an initial bonding area between a portion of the first substrate and a portion of the second substrate; and a stage of bonding the first substrate and the second substrate by releasing the second substrate having the initial bonding area formed thereon from the second holding portion, wherein the initial bonding area is set based on information related to deformation of the second substrate.

[0010] In one embodiment of the present invention, a calculation method is provided, which calculates parameters used when a first substrate and a second substrate deformed into a convex shape are brought into contact with each other while being held separately and the first substrate and the second substrate are bonded together by releasing the holding of the second substrate, wherein the calculation method has the following stages: calculating at least one parameter of the amount of convexity that causes the second substrate to be deformed into a convex shape, the adsorption area of ​​the outer peripheral portion of the second substrate to be adsorbed in order to hold the second substrate, and the timing of releasing the holding of the second substrate based on information related to the deformation of the second substrate.

[0011] In one embodiment of the present invention, a substrate bonding method is provided, comprising: a stage of holding a first substrate on a first holding portion; a stage of holding a second substrate on a second holding portion; a stage of forming an initial bonding area between a portion of the first substrate and a portion of the second substrate; and a stage of bonding the first substrate and the second substrate by releasing the second substrate having the initial bonding area formed thereon from the second holding portion, wherein the initial bonding area is a size at which the positional offset between the first substrate and the second substrate after bonding is below a threshold value.

[0012] In one embodiment of the present invention, a substrate bonding method is provided, comprising: a stage of holding a first substrate on a first holding portion; a stage of holding a second substrate on a second holding portion; a stage of forming an initial bonding area between a portion of the first substrate and a portion of the second substrate; a stage of judging whether the initial bonding area is formed; and a stage of bonding the first substrate and the second substrate by releasing the second substrate having the initial bonding area formed thereon from the second holding portion when it is judged that the initial bonding area is formed.

[0013] The above summary of the invention does not list all the essential features of the present invention. Sub-combinations of these feature groups may also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a schematic top view of the substrate bonding apparatus 100 .

[0015] Figure 2 is a schematic top view of the substrates 210 and 230 .

[0016] Figure 3 This is a flowchart showing a procedure for laminating the substrates 210 and 230 to produce the laminated substrate 290 .

[0017] Figure 4 1 and 2 . A schematic plan view (A) of the substrate holder 220 and a schematic cross-sectional view (B) of the substrate holder 220 holding the substrate 210 when cut along line II of the schematic plan view (A).

[0018] Figure 5 1 and 2 are a schematic plan view (A) of the substrate holder 240 and a schematic cross-sectional view (B) of the substrate holder 240 holding the substrate 230 when cut along line II-II of the schematic plan view (A).

[0019] Figure 6 3 is a schematic cross-sectional view of the bonding portion 300 .

[0020] Figure 7 3 is a schematic cross-sectional view of the bonding portion 300 .

[0021] Figure 8 3 is a schematic cross-sectional view of the bonding portion 300 .

[0022] Fig. 9 3 is a schematic cross-sectional view of the bonding portion 300 .

[0023] Fig.10 It is a schematic cross-sectional view showing the state of the substrates 210 and 230 in the process of bonding.

[0024] Fig.11 3 is a schematic cross-sectional view of the bonding portion 300 .

[0025] Fig.12 It is a schematic cross-sectional view showing the state of the substrates 210 and 230 in the process of bonding.

[0026] Fig.13 It is a schematic plan view showing the state of the substrates 210 and 230 during the bonding process.

[0027] Fig.14It is a schematic cross-sectional view showing the state of the substrates 210 and 230 in the process of bonding.

[0028] Fig.15 This is a schematic cross-sectional view for explaining the operation of the detector 342 .

[0029] Fig.16 This is a schematic cross-sectional view for explaining the operation of the detector 342 .

[0030] Fig.17 It is a schematic plan view showing the state of the substrates 210 and 230 during the bonding process.

[0031] Fig.18 It is a schematic cross-sectional view showing the state of the substrates 210 and 230 in the process of bonding.

[0032] Fig.19 It is a partially enlarged view showing a bonding process of the substrates 210 and 230 on the substrate holder 240 for the fixed side having a flat holding surface.

[0033] Fig. 20 It is a partially enlarged view showing a bonding process of the substrates 210 and 230 on the substrate holder 240 for the fixed side having a flat holding surface.

[0034] Fig.21 It is a partially enlarged view showing a bonding process of the substrates 210 and 230 on the substrate holder 240 for the fixed side having a flat holding surface.

[0035] Fig. 22 This is a schematic diagram showing positional deviation on a stacked substrate 290 due to magnification strain caused by air resistance generated when a substrate holder 240 for the fixed side having a flat holding surface is used.

[0036] Fig.23 This is a partially enlarged view showing a bonding process of the substrates 210 and 230 on the substrate holder 240 when the magnification distortion caused by air resistance is corrected using the substrate holder 240 for the fixed side having a curved holding surface.

[0037] Fig.24 This is a model showing the relationship between the crystal anisotropy and the Young's modulus in the silicon single crystal substrate 208 .

[0038] Fig.25 This is a model showing the relationship between the crystal anisotropy and the Young's modulus in the silicon single crystal substrate 209 .

[0039] Fig.26It is a schematic diagram of substrates 610, 630 having a plurality of circuit areas 216 formed on the surface thereof, the configuration of which is pre-corrected in such a manner that the amount of positional deviation on the stacked substrate 290 caused by the magnification deformation due to air resistance generated during bonding and the deformation due to crystal anisotropy is below a predetermined threshold.

[0040] Fig. 27 This is a schematic diagram showing positional deviation on the stacked substrate 290 due to nonlinear deformation generated when the substrate 210 on the release side has a local bend.

[0041] Fig.28 This is a diagram for explaining the method of measuring deflection and calculating warpage.

[0042] Fig.29 The diagram is an explanatory diagram for explaining a comparison between a process (A) of laminating substrates 210 and 230 using a substrate holder 820 having an outer peripheral ventilation path 822 and a process (B) of laminating substrates 210 and 230 using a substrate holder 220 having an outermost peripheral ventilation path 622 .

[0043] Fig.30 is a schematic top view of the substrate holder 920 .

[0044] Fig.31 is Fig.30 Schematic cross-sectional view of the substrate holder 920 holding the substrate 210 when the schematic top view is cut along line III-III.

[0045] Fig.32 This is an explanatory diagram for explaining a process of bonding the substrates 210 and 230 together using a substrate holder 920 having an inner peripheral ventilation path 931 , an outer peripheral ventilation path 932 , and an outermost peripheral ventilation path 933 .

[0046] Fig.33 This is an explanatory diagram for explaining a case where the setting of the initial bonding region is changed according to the presence or absence of overall warping in the substrate 210 on the release side. DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the invention will be described. The following embodiments do not limit the invention according to the claims. All combinations of features described in the embodiments are not necessarily essential to the solution means of the invention.

[0048] Figure 11 is a schematic top view of a substrate bonding apparatus 100. The substrate bonding apparatus 100 includes: a housing 110; a substrate box 120 for storing substrates 210 and 230 to be bonded; a substrate box 130 for storing a laminated substrate 290 formed by bonding at least two substrates 210 and 230; a control unit 150; a conveying unit 140; a bonding unit 300; a holder stocker 400 for storing substrate holders 220 and 240 for holding the substrates 210 and 230; and a pre-aligner 500. The interior of the housing 110 is temperature-controlled, for example, maintained at room temperature.

[0049] The conveying unit 140 conveys individual substrates 210, 230, substrate holders 220, 240, substrate holders 220, 240 holding substrates 210, 230, and a stacked substrate 290 formed by stacking a plurality of substrates 210, 230. The control unit 150 coordinates the various parts of the substrate bonding apparatus 100 to perform unified control. In addition, the control unit 150 receives instructions from an external user and sets manufacturing conditions when manufacturing the stacked substrate 290. In addition, the control unit 150 also has a user interface for displaying the operating state of the substrate bonding apparatus 100 to the outside.

[0050] The laminating unit 300 has a pair of opposing work tables that hold substrates 210 and 230 via substrate holders 220 and 240, respectively. After the pair of substrates 210 and 230 held on the pair of work tables are aligned with each other, the laminating unit 300 releases the holding of the other substrate while maintaining the holding of one of the pair of substrates 210 and 230, and releases the other substrate toward one of the pair of substrates, thereby bringing the pair of substrates 210 and 230 into contact with each other and laminating them, thereby forming a stacked substrate 290. In the following description, the substrate 210 is sometimes referred to as a substrate 210 on the fixed side, and the substrate 230 is sometimes referred to as a substrate 230 on the released side.

[0051] The pre-aligner 500 aligns the substrates 210, 230 with the substrate holders 220, 240, respectively, and holds the substrates 210, 230 on the substrate holders 220, 240. The substrate holders 220, 240 are formed of hard materials such as alumina ceramics, and hold the substrates 210, 230 by suction using an electrostatic chuck, a vacuum chuck, or the like.

[0052] In the above-mentioned substrate bonding device 100, in addition to the substrates 210 and 230 formed with elements, circuits, terminals, etc., it is also possible to bond unprocessed silicon wafers, SiGe substrates with Ge added, Ge single crystal substrates, III-V group or II-VI group compound semiconductor wafers, glass substrates, etc. The bonding object can be a circuit substrate and an unprocessed substrate, or unprocessed substrates can be each other. The bonded substrates 210 and 230 themselves can also be a stacked substrate 290 having a plurality of stacked substrates.

[0053] Figure 2 2 is a schematic top view of substrates 210 and 230 bonded in the substrate bonding apparatus 100. The substrates 210 and 230 have notches 214 and 234, a plurality of circuit regions 216 and 236, and a plurality of alignment marks 218 and 238, respectively.

[0054] The plurality of circuit regions 216 and 236 are examples of structures formed on the surfaces of the substrates 210 and 230, and are periodically arranged on the surfaces of the substrates 210 and 230 in the surface direction. Each of the plurality of circuit regions 216 and 236 is provided with structures such as wiring and protective films formed by photolithography technology or the like. The plurality of circuit regions 216 and 236 are also provided with connection portions such as pads and bumps that serve as connection terminals when the substrates 210 and 230 are electrically connected to other substrates 230 and 210, lead frames, etc. The connection portion is also an example of a structure formed on the surfaces of the substrates 210 and 230.

[0055] In addition, the plurality of alignment marks 218, 238 are also examples of structures formed on the surfaces of the substrates 210, 230, and are disposed on the scribe lines 212, 232 disposed between the plurality of circuit regions 216, 236. The plurality of alignment marks 218, 238 are indicators for aligning the substrates 210, 230 with other substrates 230, 210.

[0056] Figure 3 It is a flowchart showing the order of laminating a pair of substrates 210 and 230 to form a laminated substrate 290 in the substrate laminating device 100. Here, it is predetermined that the substrate 230 is the fixed side of a pair of workbenches of the laminating section 300, and the substrate 210 is the release side. First, the control section 150 obtains at least information related to the local bending in the substrate 210 on the release side (step S101), and based on the characteristics of the local bending of the substrate 210 contained in the acquired information, a partial area of ​​the laminating surface of the substrate 210 on the release side, that is, the initial laminating area is pre-set (step S102). In addition, the information related to the local bending is included in the information related to the deformation. In addition, the control section 150 is an example of a setting section that sets the initial laminating area based on the information related to the deformation.

[0057] Next, based on the output from the control unit 150, the conveying unit 140 sequentially carries the substrate holder 220 for the release side and the substrate 210 on the release side into the pre-aligner 500 (step S103). In the pre-aligner 500, the substrate 210 is held by the substrate holder 220 for the release side (step S104). As for the substrate 230 on the fixed side, similarly to the substrate 210, based on the output from the control unit 150, the conveying unit 140 sequentially carries the substrate holder 240 for the fixed side and the substrate 230 on the fixed side into the pre-aligner 500 (step S103), and in the pre-aligner 500, the substrate 230 is held by the substrate holder 240 for the fixed side (step S104).

[0058] Figure 4 1 and 2. The schematic top view (A) of the substrate holder 220 used in step S104 and the schematic cross-sectional view (B) of the substrate holder 220 holding the substrate 210 when cut along the line II bent at the center of the substrate holder 220 in the schematic top view (A). The substrate holder 220 has a main body 229 and a protruding member 250.

[0059] The main body 229 has: a flat holding surface 221; three annular support parts 225, 226, and 227, which are formed concentrically with the center of the substrate holder 220 on the holding surface 221; a plurality of support pins 224, which are formed at approximately equal intervals between the plurality of support parts 225 on the holding surface 221; and a recess 223, which is formed in a cylindrical shape with one end released in the approximate center of the holding surface 221. The three support parts 225, 226, and 227 are arranged in sequence from the center side of the substrate holder 220. The inner peripheral surface of the support part 225 is aligned with the inner peripheral surface of the cylindrical recess 223, and surrounds the periphery of the recess 223 on the holding surface 221. The support part 227 has an outer shape that is approximately the same as the outer shape of the substrate 210 held by the substrate holder 220. The support portion 226 is located on the holding surface 221 slightly closer to the center than the support portion 227, and together with the support portion 227, forms an annular groove on the outermost peripheral side of the substrate holder 220. The density of the plurality of support pins 224 formed between the support portion 225 and the support portion 226 is sparser than the density of the plurality of support pins 224 formed between the support portion 226 and the support portion 227. The support portion 225 and the plurality of support pins 224 protrude from the holding surface 221 by the same amount, and the protruding front ends are located on the same plane. Therefore, the support portion 225 and the plurality of support pins 224 all contact the substrate 210 placed on the substrate holder 220. In addition, in Figure 4In (A), for the sake of clarity of the description, the illustration of the plurality of support pins 224 is omitted. Hereinafter, the region on the radially central side of the surface of the substrate 210 and the region adsorbed between the support portion 225 and the support portion 226 of the substrate holder 220 is sometimes referred to as the inner peripheral region of the substrate 210. In addition, the region on the radially outer side of the surface of the substrate 210 and the region adsorbed between the support portion 226 and the support portion 227 of the substrate holder 220 is sometimes referred to as the outermost peripheral region of the substrate 210.

[0060] The main body 229 further includes: two leaf springs 255, the outer peripheries of which are connected to the inner periphery of the recess 223; and a cylindrical protruding member 250, the outer periphery of which is connected to the inner periphery of the two leaf springs 255. The leaf springs 255 are elastically deformed by receiving a force in a direction away from the recess 223 of a certain value or more from the outside, so that the protruding member 250 protrudes from the plane where the respective protruding front ends of the support portion 225 and the plurality of support pins 224 are located. The protruding member 250 does not protrude from the plane when the leaf springs 255 do not receive a force in a direction away from the recess 223 of a certain value or more from the outside. In addition, the protruding member 250 may be configured such that it protrudes from the plane by the elastic force of the leaf springs 255, and is pressed into the recess 223 when receiving a pressing load of a certain value or more from the outside toward the recess 223. In this case, the elastic force of the leaf springs 255 has at least the force required to deform the substrate 210.

[0061] The main body 229 further includes a central ventilation path 625, an inner peripheral ventilation path 621, and an outermost peripheral ventilation path 622. The central ventilation path 625 has an exhaust hole opened at the bottom surface of the recess 223 at one end, and the other end is selectively connected to the positive pressure source 731 and the open end 741 via the control valve 721 outside the substrate holder 220. The inner peripheral ventilation path 621 has a plurality of suction holes arranged at approximately equal intervals at one end, and the plurality of suction holes are opened at a portion between the support portion 225 and the support portion 226 on the holding surface 221 and where the plurality of support pins 224 are not formed, and the other end is selectively connected to the negative pressure source 734 and the open end 744 via the control valve 724 outside the substrate holder 220. The outermost peripheral ventilation path 622 has a plurality of suction holes arranged at approximately equal intervals at one end, and the plurality of suction holes are open between the support portion 226 and the support portion 227 on the holding surface 221 and at a portion where the plurality of support pins 224 are not formed, and the other end is selectively connected to the negative pressure source 737 and the open end 747 via a control valve 727 outside the substrate holder 220. The number of the plurality of suction holes at one end of the outermost peripheral ventilation path 622 is greater than the number of the plurality of suction holes at one end of the inner peripheral ventilation path 621, and they are arranged more densely. The plurality of suction holes at one end of the outermost peripheral ventilation path 622 are provided at the outermost periphery of the substrate holder 220 in order to be able to adsorb the outermost peripheral region of the substrate 210, but as Figure 4 As shown in (B), the outermost peripheral ventilation path 622 is formed to extend in the surface direction inside the substrate holder 220, so that the other end thereof is arranged close to the center side of the substrate holder 220. Thus, the substrate holder 220 can also be applied to a vacuum plate or a substrate bonding workbench, which holds the substrate holder 220 and concentrates air pipes for providing suction or exhaust to each ventilation path of the substrate holder 220 at the center of the holding surface of the substrate holder 220.

[0062] Under the control of the control unit 150, the control valves 724 and 727 selectively connect the inner circumferential ventilation path 621 and the outermost circumferential ventilation path 622 to the negative pressure sources 734 and 737, respectively. When the substrate 210 is placed on the support portion 225 and the plurality of support pins 224, and the control valves 724 and 727 connect the inner circumferential ventilation path 621 and the outermost circumferential ventilation path 622 to the negative pressure sources 734 and 737, respectively, negative pressure is applied to the plurality of suction holes of the inner circumferential ventilation path 621 and the outermost circumferential ventilation path 622. As a result, the space between the substrate 210 and the holding surface 221 and between the support portion 225 and the support portion 226, and the space between the support portion 226 and the support portion 227 are decompressed, and the substrate 210 is adsorbed to the substrate holder 220. On the other hand, when the substrate 210 is adsorbed on the substrate holder 220, the control valves 724 and 727 communicate the inner peripheral ventilation path 621 and the outermost peripheral ventilation path 622 with the open ends 744 and 747, respectively, and the substrate holder 220 releases the adsorption of the substrate 210. The inner peripheral ventilation path 621 and the outermost peripheral ventilation path 622 are respectively connected to the control valves 724 and 727 controlled individually by the control unit 150, and the plurality of adsorption holes at one end of each are opened in each space isolated from each other by the support unit 226. Therefore, the substrate holder 220 can adsorb the inner peripheral region and the outermost peripheral region of the substrate 210 separately under the control of the control unit 150, and can release the adsorption separately. In other words, the substrate holder 220 has two adsorption regions that are isolated and independent from each other.

[0063] The control valve 721 selectively connects the central air passage 625 with the positive pressure source 731 and the open end 741 under the control of the control unit 150. When the control valve 721 connects the central air passage 625 with the positive pressure source 731, positive pressure acts on the exhaust hole of the central air passage 625, and the space surrounded by the recess 223, the plate spring 255, and the protruding member 250 is pressurized. The plate spring 255 is elastically deformed in a direction away from the recess 223, so that the protruding member 250 protrudes from the above-mentioned plane, and as a result, a part of the substrate 210 located inside the support portion 225 is deformed in this direction. The substrate holder 220 deforms the substrate 210 in this way while adsorbing the substrate 210 under the control of the control unit 150, so that the part of the substrate 210 can be rapidly protruded in a direction away from the substrate holder 220, and the amount of protrusion can be adjusted by adjusting the applied load. The control unit 150 sets the protrusion amount of the protrusion member 250 based on the local bending characteristics of the substrate 210. The control unit 150 adjusts the size of the initial bonding area 803 by adjusting the protrusion amount of the protrusion member 250.

[0064] exist Figure 4 The schematic cross-sectional view of (B) shows a state in which, in a state in which the substrate holder 220 adsorbs the substrate 210, the protruding member 250 is made to protrude from the above-mentioned plane, so that the area C near the center of the substrate 210 protrudes sharply. In the figure, the height A to the abutment portion 251 of the protruding member 250 is higher than the sum B of the depth of the recessed portion 223 and the height of the supporting portion 225, and the abutment portion 251 protrudes from the above-mentioned plane. As a result, a bulge 215 protruding sharply is formed in the area C near the center of the flat substrate 210 adsorbed on the substrate holder 220. The height D of the bulge 215 is the same as or slightly higher than the amount by which the abutment portion 251 of the protruding member 250 protrudes from the above-mentioned plane. For example, when the amount by which the abutment portion 251 protrudes is 50 μm, the height D of the bulge 215 is about 70 μm.

[0065] The main body 229 further includes: three observation holes 601, 602, and 603 that penetrate the substrate holder 220 in the thickness direction, which are formed between the support portion 225 and the support portion 226 on the holding surface 221 and at three locations where the plurality of support pins 224 are not formed; and an observation hole 604 that penetrates the substrate holder 220 in the thickness direction, which is formed between the support portion 226 and the support portion 227 on the holding surface 221. The four observation holes 601, 602, 603, and 604 are as shown in Figure 4As shown in the schematic top view of (A) of FIG. 1 , which overlaps with the straight II line bent at the center of the substrate holder 220, it is located on the substantially same straight line along the radial direction of the substrate holder 220. The three observation holes 601, 602, and 603 are arranged near the center of the substrate holder 220 and are arranged in sequence at substantially equal intervals from the center side of the substrate holder 220. In addition, the observation holes 601 and the like are filled with a material that is transparent to the wavelength of the illumination light used when observing the substrate 210, and both ends of the observation holes 601 and the like are smoothly formed together with the two planes of the substrate holder 220.

[0066] The substrate holder 220 is aligned with the substrate 210 in such a manner that a predetermined portion of the substrate 210 faces the observation hole 601 of the substrate holder 220. Specifically, based on the information on the local curvature of the substrate 210 transmitted from the control unit 150 of the substrate bonding apparatus 100, the pre-aligner 500 aligns the substrate holder 220 with the substrate 210 in such a manner that the predetermined portion of the substrate 210 is located on the line where the observation holes 601 to 604 provided in the substrate holder 220 are located. For example, the pre-aligner 500 performs alignment in such a manner that the portion of the substrate 210 with the largest local curvature in the plane is located on the line where the observation holes 601 to 604 provided in the substrate holder 220 are located.

[0067] Furthermore, although the structure in which the protrusion amount of the protrusion member 250 of the substrate holder 220 is adjusted by air pressure has been described, the protrusion member 250 may be replaced with a detachable structure, and the protrusion amount may be variable by replacing a plurality of protrusion members 250 of different heights. Thus, as with the protrusion member 250 of air pressure type, a desired protrusion amount can be provided.

[0068] Figure 5 1 and 2 are a schematic plan view (A) of the substrate holder 240 and a schematic cross-sectional view (B) of the substrate holder 240 holding the substrate 230 when cut along line II-II of the schematic plan view (A). The substrate holder 240 has a main body 249 .

[0069] The main body 249 has: a flat holding surface 241; an annular support portion 247, which is formed concentrically with the center of the substrate holder 240 on the holding surface 241; and a plurality of support pins 244, which are formed at approximately equal intervals on the inner side of the support portion 247 on the holding surface 241. The support portion 247 has an outer shape that is approximately the same as the outer shape of the substrate 230 held on the substrate holder 240. The support portion 247 and the plurality of support pins 244 protrude from the holding surface 241 by the same amount, and the protruding front ends are located on the same plane. Therefore, the support portion 247 and the protruding front ends of the plurality of support pins 244 are in contact with the substrate 230 placed on the substrate holder 240. In addition, in Figure 5 In (A), for the sake of clarity of explanation, illustration of the plurality of support pins 244 is omitted.

[0070] The main body 249 further includes a ventilation path 640, which has a plurality of air intake holes arranged at approximately equal intervals at one end, the plurality of air intake holes opening at a location where the plurality of support pins 244 are not formed and the other end selectively connected to the negative pressure source 761 and the open end 771 via a control valve 751 outside the substrate holder 240. The plurality of air intake holes at one end of the ventilation path 640 are provided to the outermost periphery of the substrate holder 240, but as shown in FIG. Figure 5 As shown in (B), the ventilation path 640 is formed to extend in the surface direction inside the substrate holder 240, so that the other end thereof is arranged approximately in the center of the substrate holder 240. Thus, the substrate holder 240, like the substrate holder 220, can also be applied to a vacuum plate or a substrate bonding workbench, which holds the substrate holder 240 and concentrates the air piping for applying suction to the ventilation path 640 of the substrate holder 240 at the center of the holding surface of the substrate holder 240.

[0071] Under the control of the control unit 150, the control valve 751 selectively connects the ventilation path 640 with the negative pressure source 761. When the substrate 230 is placed on the support portion 247 and the plurality of support pins 244, and when the control valve 751 connects the ventilation path 640 with the negative pressure source 761, negative pressure is applied to the plurality of suction holes of the ventilation path 640. As a result, the space between the substrate 230 and the holding surface 241 and inside the support portion 227 is decompressed, and the substrate 230 is adsorbed onto the substrate holder 240. On the other hand, when the control valve 751 connects the ventilation path 640 with the open end 771 from the state where the substrate 230 is adsorbed onto the substrate holder 240, the adsorption of the substrate 230 by the substrate holder 240 is released. Figure 5 The schematic cross-sectional view of (B) shows a state where the substrate holder 240 absorbs the substrate 230 , and the substrate 230 absorbed by the substrate holder 240 is located on the above-mentioned plane and is in a flat state.

[0072] In addition, it is explained Figure 4 and Figure 5The substrate holders 220 and 240 shown respectively are both cases where the cross-sectional shape of the main body 229 and 249 is approximately square, but instead, they may have a cross-sectional shape in which the thickness gradually increases from the peripheral portion toward the central portion. As a result, the substrates 210 and 230 adsorbed and held by the substrate holders 220 and 240 are closely attached to the holding surfaces 221 and 241, and the entirety is curved to imitate the shape of the holding surfaces 221 and 241. Therefore, when the surfaces of the holding surfaces 221 and 241 are curved surfaces, such as cylindrical surfaces, spherical surfaces, parabolic surfaces, etc., the shape of the entirety of the adsorbed substrates 210 and 230 also changes to form such a curved surface.

[0073] like Figure 6 As shown in FIG. 1 , the substrate holders 220 and 240 that individually hold the substrates 210 and 230 are sequentially carried into the laminating unit 300 and fixed to each workbench (step S105). Figures 6 to 9 and Fig.11 3 is a schematic cross-sectional view of the laminating unit 300. Here, the laminating unit 300 includes a frame 310, an upper stage 322, and a lower stage 332.

[0074] The upper workbench 322 is fixed downward to the top plate 316 of the frame 310. The upper workbench 322 has a holding function of a vacuum chuck, an electrostatic chuck, etc. In the state shown in the figure, the substrate holder 220 holding the substrate 210 is already held on the upper workbench 322. The upper workbench 322 has four observation windows 361, 362, 363, and 364 arranged corresponding to the positions of the four observation holes 601, 602, 603, and 604 of the held substrate holder 220. The observation windows 361, etc. are respectively filled with a material that is transparent to the wavelength of the illumination light used when observing the substrate 210, and the lower surface of the upper workbench 322 also includes the area where the observation windows 361, etc. are formed, forming a flat surface.

[0075] The laminating section 300 further includes four detectors 341, 342, 343, and 344 provided at positions corresponding to the four observation windows 361 of the upper work table 322 and penetrating the top plate 316 of the frame body 310 in the thickness direction. The four detectors 341 and the like form an observation section 345, which observes the expansion of the laminating area between the substrates 210 and 230 in the laminating section 300 through the four observation windows 361 and the like optically connected to the lower surface of the upper work table 322 and the four observation holes 601 and the like of the substrate holder 220. The observation section 345 is an example of a determination section that determines that the initial laminating area is laminating.

[0076] The four detectors 341, etc. can be formed, for example, using a light receiving unit and a light source. In this case, if the substrate holder 220 holding the substrate 210 is held on the upper workbench 322, the light intensity of the reflected light based on the substrates 210, 230, etc. can be detected by the four detectors 341, etc. through the four observation windows 361, etc. and the four observation holes 601, etc.

[0077] The lower workbench 332 of the laminating unit 300 is mounted on the upper surface of the Y-direction driving unit 333 in the figure, which overlaps with the X-direction driving unit 331 provided on the bottom plate 312 of the frame 310. The lower workbench 332 also has a holding function of a vacuum chuck, an electrostatic chuck, etc. In the state shown in the figure, the substrate holder 240 holding the substrate 230 is already held on the lower workbench 332.

[0078] On the top plate 316, a microscope 324 and an activation device 326 are fixed to the side of the upper stage 322. The microscope 324 can observe the upper surface of the substrate 230 indirectly held by the lower stage 332. The activation device 326 generates plasma to purify the upper surface of the substrate 230 indirectly held by the lower stage 332.

[0079] The X-direction driving unit 331 moves in the direction indicated by the arrow X in the figure in parallel with the bottom plate 312. The Y-direction driving unit 333 moves in the direction indicated by the arrow Y in the figure in parallel with the bottom plate 312 on the X-direction driving unit 331. By combining the actions of the X-direction driving unit 331 and the Y-direction driving unit 333, the lower worktable 332 moves two-dimensionally in parallel with the bottom plate 312.

[0080] In addition, the lower table 332 is supported by a lifting drive unit 338 that is lifted and lowered in the direction indicated by the arrow Z perpendicular to the bottom plate 312. Thus, the lower table 332 can be lifted and lowered relative to the Y-direction drive unit 333. In this way, the lower table 332 is between the upper table 322 that holds the substrate holder 220 holding the substrate 210, and the relative position of the substrate 210 held by the substrate holder 220 and the substrate 230 held by the substrate holder 240 is displaced.

[0081] The amount of movement of the lower table 332 by the X-direction drive unit 331 , the Y-direction drive unit 333 , and the lifting drive unit 338 is precisely measured using an interferometer or the like.

[0082] In the Y-direction driving unit 333, a microscope 334 and an activation device 336 are respectively mounted on the side of the lower workbench 332. The microscope 334 can observe the lower surface of the substrate 210 facing downward and indirectly held by the upper workbench 322. The activation device 336 generates plasma for purifying the lower surface of the substrate 210 indirectly held by the upper workbench 322. In addition, the activation devices 326 and 336 may be provided in a device different from the laminating unit 300, and the substrate and the substrate holder whose upper surface is activated may be transported from the activation devices 326 and 336 to the laminating unit 300 by a robot.

[0083] In addition, the laminating unit 300 may further include: a rotation drive unit that rotates the lower table 332 around a rotation axis perpendicular to the bottom plate 312; and a swing drive unit that swings the lower table 332. Thus, the lower table 332 is parallel to the upper table 322, and the substrate 210 indirectly held by the lower table 332 is rotated, which can improve the alignment accuracy of the substrates 210 and 230.

[0084] The microscopes 324 and 334 are focused on each other or observe a common index, and then are calibrated by the control unit 150. Thus, the relative positions of the pair of microscopes 324 and 334 in the bonding unit 300 are measured.

[0085] Next Figure 6 The status shown is Figure 7 As shown, the control unit 150 operates the X-direction drive unit 331 and the Y-direction drive unit 333 to detect the alignment marks 218 and 238 respectively provided on the substrates 210 and 230 by the microscopes 324 and 334 (step S106).

[0086] Next, the positions of the alignment marks 218 and 238 of the substrates 210 and 230 are detected by using the microscopes 324 and 334 whose relative positions are known, thereby calculating the relative positions of the substrates 210 and 230 (step S107). Thus, when the substrates 210 and 230 are aligned, the relative movement amount of the substrates 210 and 230 can be calculated in such a way that the positional offset between the corresponding alignment marks 218 and 238 in a pair of substrates 210 and 230 is less than a predetermined threshold value, or the positional offset between the corresponding circuit regions 216 and 236 or the connection parts between the substrates 210 and 230 is less than a predetermined threshold value. The positional offset refers to the positional offset between the corresponding alignment marks 218 and 238 between the stacked substrates 210 and 230, and the positional offset between the corresponding connection parts, including the positional offset caused by the difference in the deformation amount generated in the two substrates 210 and 230.

[0087] Here, the so-called threshold value for the above-mentioned positional offset may be an offset at which electrical conduction can be achieved between the substrates 210 and 230 when the mutual bonding of the substrates 210 and 230 is completed, or an offset when the structures respectively provided on the substrates 210 and 230 are in contact with each other at least in part. When the positional offset between the substrates 210 and 230 is greater than the threshold value, the control unit 150 may also determine that the connection parts are not in contact with each other or cannot obtain appropriate electrical conduction, or that the specified bonding strength cannot be obtained between the bonding parts. In addition, in the case of pre-processing the deformation of the substrates 210 and 230 generated during the bonding process before bonding, that is, in the case of deforming at least one of the substrates 210 and 230 before bonding to correct the positional offset caused by the deformation when the bonding is completed, the position of one substrate in a deformed state may be used as a reference to set the threshold value.

[0088] Next Figure 7 The status shown is Figure 8 As shown, the control unit 150 records the relative positions of a pair of substrates 210 and 230, and chemically activates the respective bonding surfaces of the pair of substrates 210 and 230 (step S108). First, the control unit 150 resets the position of the lower workbench 332 to the initial position and then moves it horizontally, and scans the surfaces of the substrates 210 and 230 through the plasma generated by the activation devices 326 and 336. As a result, the surfaces of the substrates 210 and 230 are purified and the chemical activity is improved. In addition, the activation of the substrates 210 and 230 in step S108 can also be performed before step S106. In addition, the activation of the substrates 210 and 230 can also be performed before the substrates 210 and 230 are moved into the substrate bonding device 100. In addition, the substrates 210 and 230 can also be temporarily moved out of the substrate bonding device 100, and after being activated outside, they can be moved into the substrate bonding device 100 again.

[0089] In addition to the method of exposing to plasma, the surfaces of the substrates 210 and 230 can also be activated by sputter etching using an inert gas, an ion beam, or a high-speed atomic beam. In the case of using an ion beam or a high-speed atomic beam, the bonding portion 300 can be generated under reduced pressure. In addition, the substrates 210 and 230 can also be activated by ultraviolet irradiation, an ozone ashing machine, or the like. Moreover, for example, the surfaces of the substrates 210 and 230 can be chemically cleaned and activated by using a liquid or gaseous etchant. After the activation of the surfaces of the substrates 210 and 230, the surfaces of the substrates 210 and 230 can also be hydrophilized by a hydrophilizing device.

[0090] Next Figure 8 The status shown is Fig. 9 As shown, the control unit 150 aligns the substrates 210 and 230 with each other ( Figure 3 First, based on the relative positions of the microscopes 324 and 334 detected initially and the positions of the alignment marks 218 and 238 of the substrates 210 and 230 detected in step S106, the control unit 150 moves the lower workbench 332 so that the positional offset of the structures corresponding to each other on the substrates 210 and 230 is at least below the threshold value when the bonding is completed.

[0091] Fig.10 It is a schematic cross-sectional view showing the state of the substrates 210 and 230 in the process of bonding. Fig.10 express Fig. 9 The state of the substrates 210 and 230 in the state of step S109 shown in the figure. As shown in the figure, the substrates 210 and 230 held on the upper worktable 322 and the lower worktable 332 via the substrate holders 220 and 240 are opposed to each other in a mutually aligned state. As shown in the figure, a sharply protruding ridge 215 is formed in a region C near the center of the flat substrate 210 adsorbed by the substrate holder 220, so that the interval between the opposing substrates 210 and 230 is smaller near the center than the interval at the peripheral portion.

[0092] Next Fig. 9 and Fig.10 The status shown is Fig.11 As shown, the control unit 150 operates the lifting drive unit 338 to raise the lower workbench 332, so that the substrates 210 and 230 are close to each other. Moreover, a part of the substrates 210 and 230 contact each other, and a contact area, that is, a bonding area, is formed (step S110). Specifically, the raised portion 215 of the substrate 210 and a part of the region of the substrate 230 opposite to the raised portion 215 contact each other, and a bonding area is formed at the activated contact portion.

[0093] Fig.12 It is a schematic cross-sectional view showing the state of the substrates 210 and 230 in the process of bonding. Fig.12 Schematically shown in cross section Fig.11The state of the substrates 210 and 230 in the state of step S110 shown in the figure. At this stage, the control unit 150 controls the control valves 724, 727, and 751 to connect the inner peripheral ventilation path 621 and the outermost peripheral ventilation path 622 of the substrate holder 220 and the ventilation path 640 of the substrate holder 240 to the negative pressure sources 734, 737, and 761, respectively. Therefore, the substrates 210 and 230 are respectively adsorbed on the substrate holders 220 and 240, and the contact of the substrates 210 and 230 at the parts other than the above-mentioned contact parts is suppressed. In this way, by using the substrate holder 220 having the protruding part 250, only one contact part is formed on the substrates 210 and 230, and as a result, the generation of gaps in the bonding surface caused by forming multiple contact parts alone can be suppressed.

[0094] Fig.13 2 is a schematic top view showing the state of the substrates 210 and 230 during the bonding process. Specifically, the schematic top view from the back side of the substrate 210 shows Fig.11 and 12 The state of the substrates 210 and 230 in step S110 is shown. A bonding region 801 is formed near the center in the plane direction between the substrates 210 and 230. Therefore, the bonding region 801 of the substrates 210 and 230 expands from the center toward the radially outer sides of the substrates 210 and 230.

[0095] exist Fig.13 In the figure, a circular initial bonding area 803 which is pre-set by the control unit 150 and is substantially concentric with the substrates 210 and 230 is represented. In the present embodiment, the structure is as follows: the control unit 150 pre-determines three concentric initial bonding areas 803 with different radii, and selects one initial bonding area 803 from the three initial bonding areas 803 based on the characteristics of the local bending of the substrate 210 contained in the information related to the local bending of the substrate 210 on the release side. With such a structure, corresponding to the three initial bonding areas 803, three observation holes 601, 602, and 603 are pre-set in the substrate holder 220, and three observation windows 361 to 363 are set on the upper workbench 322 of the bonding unit 300. When the control unit 150 selects an initial bonding area 803 based on the characteristics of the local bending of the substrate 210 on the release side, the corresponding observation holes, observation windows, and detectors are used. Fig.13 , it represents the situation where the corresponding observation hole 602 is located at the periphery of the selected initial bonding area 803.

[0096] Fig.14 2 is a schematic cross-sectional view showing the state of the substrates 210 and 230 during the bonding process. Fig.12 and Fig.13 The status shown is Fig.14As shown, the control unit 150 switches the control valve 724 on the upper workbench 322 to connect the inner peripheral ventilation path 621 of the substrate holder 220 to the open end 744. As a result, the inner peripheral area of ​​the substrate 210 on the upper side of the figure is released from the retention based on the substrate holder 220 (step S111), and the substrates 210 and 230 are autonomously bonded to each other through the intermolecular forces between the activated surfaces. During this period, the outermost peripheral ventilation path 622 of the substrate holder 220 is still maintained in a state of being connected to the negative pressure source 737. As a result, the outermost peripheral area of ​​the substrate 210 on the upper side of the figure continues to be maintained by the substrate holder 220.

[0097] Since the surfaces of the substrates 210 and 230 are activated, if they are partially in contact, the adjacent regions are autonomously adsorbed and bonded to each other due to the intermolecular force between the substrates 210 and 230. Therefore, for example, the substrate 230 is held by the substrate holder 240 held by the upper stage 322, and the bonded region of the substrates 210 and 230 is sequentially expanded from the contacted portion to the adjacent region. Thus, a bonding wave is generated in which the bonded region is sequentially expanded, and the bonding of the substrates 210 and 230 proceeds.

[0098] After executing step S111 , the control unit 150 determines whether the initial bonding area 803 has been bonded (step S112 ). Fig.15 and 16 This is a schematic cross-sectional view for explaining the operation of the detector 342 . Fig.15 This is a diagram showing a state before the substrates 210 and 230 come into contact with each other in a partially enlarged manner in the detection range of the detector 342 used for one initial bonding area 803 selected from the three initial bonding areas 803 after the execution of step S111. Fig.15 The area shown is Fig.14 The area indicated by the dotted line B corresponds to this.

[0099] In the state shown in the figure, a gap G2 remains between the substrates 210 and 230. The gap G2 is formed by the substrates 210 and 230 being sandwiched by the ambient gas or the like inside the bonding unit 300. The ambient gas or the like sandwiched by the substrates 210 and 230 is squeezed out because the adjacent regions are autonomously adsorbed to each other and sequentially bonded due to the intermolecular force between the substrates 210 and 230, and finally the substrates 210 and 230 are closely bonded to each other, but due to the local bending characteristics of the substrate 210 on the release side, the density of the sandwiched ambient gas, etc., the time required until the substrates 210 and 230 are bonded may be different in the circumferential direction of the substrates 210 and 230. Of course, the time may be different for each substrate 210 and 230, each type of substrate 210 and 230, each manufacturing process, or each manufacturing batch.

[0100] In the laminating section 300, even when the substrates 210 and 230 are sandwiched between the upper stage 322 and the lower stage 332, the peripheral area of ​​the initial laminating area 803 of the substrate 210 is optically connected to the detector 342 through the observation hole 602 and the observation window 362. In the example shown in the figure, the detector 342 includes a light source 351 and a light receiving unit 352.

[0101] The light source 351 generates irradiation light of a wavelength that at least partially transmits the substrate 210. The irradiation light generated by the light source 351 is irradiated toward the substrate 210 through the observation window 362 and the observation hole 602. The light receiving unit 352 has a photoelectric conversion element such as a photodiode, receives the irradiation light reflected by the substrates 210, 230, etc., and generates an electrical signal corresponding to the intensity of the reflected light. The electrical signal generated by the light receiving unit 352 is input to the control unit 150.

[0102] As indicated by the single-dot chain line in the figure, a reflection surface is formed at the boundary of the media with different bending rates between the upper worktable 322 and the lower worktable 332. In the example shown in the figure, reflection surfaces O, P, Q, R, S, and T are formed at the boundary between the observation hole 602 and the gap G1, the boundary between the gap G1 and the substrate 210, the boundary between the substrate 210 and the gap G2, the boundary between the gap G2 and the substrate 230, the boundary between the substrate 230 and the gap G3, and the boundary between the gap G3 and the substrate holder 240, respectively. Therefore, the irradiation light irradiated from the light source 351 of the detector 342 through the observation window 362 and the observation hole 602 is reflected on each of the reflection surfaces O, P, Q, R, S, and T, and is incident on the light receiving unit 352 through the observation hole 602 and the observation window 362 again, thereby detecting the intensity of the reflected light.

[0103] Fig.16 is with Fig.15 In the same viewpoint, after executing step S111, a partially enlarged diagram shows the state of the initial bonding area 803 of the substrate 210 being bonded. If the substrates 210 and 230 are bonded and closely attached to each other, the pair of reflection surfaces R and Q formed between the substrates 210 and 230 and the gap G2 disappear. Therefore, the number of reflection surfaces that reflect the irradiated light of the detector 342 is reduced, and the intensity of the reflected light detected by the detector 342 is reduced. Therefore, the control unit 150 can determine that the initial bonding area 803 of the substrate 210 is bonded based on the detection information output from the detector 342. In addition, during the reduction process of the gap G2 before the gap G2 disappears, the intensity of the reflected light detected by the detector 342 changes, but the intensity of the reflected light does not decrease as the gap G2 decreases, but the light and dark of the reflected light are repeated due to interference between the irradiated light and the reflected light.

[0104] Fig.172 is a schematic top view showing the state of the substrates 210 and 230 during the bonding process. Specifically, the schematic top view from the back side of the substrate 210 shows Fig.16 The state of the substrates 210 and 230 is shown. Fig.13 The bonding region 801 of the substrates 210 and 230 shown in the figure expands from the vicinity of the center of the substrates 210 and 230 toward the radially outer side, but the extent of the expansion of the bonding region 801 is irregular in the circumferential direction of the substrates 210 and 230 .

[0105] After executing step S111, the control unit 150 continues to receive detection information from the detector 342 and continues to make judgments when it is determined that the initial bonding area 803 of the substrate 210 is not bonded based on the detection information output from the detector 342 (step S112: No). When it is determined that the initial bonding area 803 of the substrate 210 is bonded (step S112: Yes), the control valve 727 is switched on the upper workbench 322 to connect the outermost peripheral ventilation path 622 of the substrate holder 220 with the open end 747. As a result, the outermost peripheral area of ​​the substrate 210 on the upper side of the figure is also released from the holding by the substrate holder 220 (step S113), and the surfaces are bonded autonomously to each other until the periphery of the substrates 210 and 230 by the intermolecular force between the activated surfaces.

[0106] That is, in the example shown in the figure, during the period from when the inner peripheral ventilation path 621 of the substrate holder 220 is connected with the open end 744 by switching the control valve 724 to generate a bonding wave of the substrate 210 until the bonding wave is stopped by the lifting force generated on the substrate 210 due to the outermost peripheral area of ​​the substrate 210 held by the substrate holder 220, when or after it is determined that the initial bonding area 803 is bonded, the outermost peripheral ventilation path 622 is connected with the open end 747, thereby releasing the outermost peripheral area of ​​the substrate 210 from the substrate holder 220.

[0107] In addition, Fig.15 and Fig.16 In the figure, in order to easily distinguish the irradiated light from the reflected light, it is described that the irradiated light is irradiated obliquely to the substrates 210 and 230. However, even if the irradiated light is irradiated perpendicularly to the substrates 210 and 230, an optical system for detecting the intensity of the reflected light can be formed by using an optical device such as a half mirror. In addition, the detector 342 can also use an image sensor such as a CCD or CMOS sensor instead of the light receiving part 352. In addition, the above-mentioned structure of the detector 342 can also be applied to Figure 6 Other detectors 341, 343, 344 are shown.

[0108] Fig.182 is a schematic cross-sectional view showing the state of the substrates 210 and 230 during the bonding process. After executing step S113, the control unit 150 determines that the bonding of the substrates 210 and 230 is not completed based on the detection information output from the detector 344 located at the periphery of the substrate 210 (step S114: No), and continues to receive the detection information from the detector 344 and continues to make judgments. If it is determined that the bonding of the substrates 210 and 230 is completed (step S114: Yes), that is, Fig.18 As shown, when the progress of the bonding wave in the bonding surface of the substrates 210 and 230 is completed, after a predetermined time, the stacked substrate 290 formed by the substrates 210 and 230 is carried out from the bonding section 300 together with the substrate holder 240 by the conveying section 140 (step S115). Then, the stacked substrate 290 and the substrate holder 240 are separated in the pre-aligner 500, and the stacked substrate 290 is transported to the substrate box 130 by the conveying section 140. In addition, the stacked substrate 290 and the substrate holder 240 may be separated in the bonding section 300, and the stacked substrate 290 alone may be carried out from the bonding section 300 by the conveying section 140 and transported to the substrate box 130.

[0109] Next, a method for setting the initial bonding area 803 is described. In particular, an example of setting the initial bonding area 803 based on the characteristics of local bending is described. Here, if the substrate 210 on the release side before bonding is locally bent, it becomes an important factor that causes nonlinear deformation during bonding. In this case, even if the substrates 210 and 230 are aligned in the surface direction based on the alignment marks 218, 238, etc. in the bonding section 300, the positional offset between the substrates 210 and 230 may not be eliminated. Therefore, in Figure 3 In step S101 and step S102 shown in FIG. 1 , the control unit 150 obtains information related to the local bending of the substrate 210 on the release side, and pre-sets the initial bonding area 803 of the substrate 210 on the release side based on the characteristics of the local bending of the substrate 210 included in the obtained information. Figures 14 to 18 As shown, the control unit 150 maintains the substrate holder 220 holding the outermost peripheral area of ​​the substrate 210 until the bonding is detected in the initial bonding area 803 which is set in advance by the bonding area 801 expanding from the center of the substrate 210 or 230 toward the periphery.

[0110] Here, the deformation generated in the substrates 210 and 230 refers to the displacement of the structures of the substrates 210 and 230 from the design coordinates, that is, the design positions. The deformation generated in the substrates 210 and 230 includes planar deformation and three-dimensional deformation.

[0111] Planar deformation is deformation of the substrates 210 and 230 in the direction along the bonding surface, including linear deformation represented by linear transformation of the positions of the structures of the substrates 210 and 230 after displacement from the designed positions, and nonlinear deformation other than linear deformation that cannot be represented by linear transformation.

[0112] Linear deformation includes rate deformation in which the displacement increases at a certain rate along the radial direction from the center. Rate deformation is a value obtained by dividing the offset from the design value at a distance X from the center of the substrate 210, 230 by X, and the unit is ppm. Rate deformation includes isotropic rate deformation. Isotropic rate deformation is a deformation in which the X component and the Y component of the displacement vector from the design position are equal, that is, the rate in the X direction is equal to the rate in the Y direction. On the other hand, non-isotropic rate deformation, a deformation in which the X component and the Y component of the displacement vector from the design position are different, that is, the rate in the X direction is different from the rate in the Y direction, is included in nonlinear deformation.

[0113] In the present embodiment, the difference in magnification strain based on the design positions of at least the circuit regions 216 and 236 in the structures of the two substrates 210 and 230 is included in the positional offset between the two substrates 210 and 230. In addition, the design positions of the circuit regions 216 and 236 of the two bonded substrates 210 and 230 may be designed to be different in consideration of the positional offset caused by the difference in magnification strain due to bonding.

[0114] In addition, linear deformation includes orthogonal deformation. Orthogonal deformation is a deformation that is displaced parallel to the X-axis direction from the design position when the X-axis and Y-axis are set orthogonal to each other with the center of the substrate as the origin. The farther the structure is from the origin in the Y-axis direction, the greater the amount is. The displacement is equal in each of the multiple areas that cross the Y-axis parallel to the X-axis, and the absolute value of the displacement increases as it moves away from the X-axis. Moreover, the direction of displacement on the positive side of the Y-axis and the direction of displacement on the negative side of the Y-axis are opposite to each other.

[0115] The three-dimensional deformation of the substrate 210, 230 is the displacement of the substrate 210, 230 in a direction other than the direction along the bonding surface, that is, in a direction intersecting the bonding surface. The three-dimensional deformation includes bending of the substrate 210, 230 as a whole or in part due to bending of the substrate 210, 230. Here, "substrate bending" means that the substrate 210, 230 changes into a shape in which a point that does not exist on the plane defined by three points on the substrate 210, 230 is included in the surface of the substrate 210, 230.

[0116] In addition, curvature refers to deformation of the surface of the substrate to form a curved surface, for example, including the warping of the substrates 210 and 230. In the present embodiment, the warping refers to deformation remaining in the substrates 210 and 230 in a state where the influence of gravity is eliminated. The deformation of the substrates 210 and 230 after the influence of gravity is given to the warping is called deflection. In addition, the warping of the substrates 210 and 230 includes: overall warping in which the substrates 210 and 230 are bent with substantially the same curvature as a whole; and local warping in which a part of the substrates 210 and 230 is bent due to a local change in curvature.

[0117] Here, the rate deformation is classified into initial rate deformation, adsorption rate deformation, and lamination process rate deformation according to the cause of occurrence.

[0118] Due to the stress generated in the process of forming the alignment mark 218, the circuit area 216, etc. on the substrates 210 and 230, the periodic rigidity change caused by the arrangement of the scribe line 212, the circuit area 216, etc., etc., as a deviation from the design specifications of the substrates 210 and 230, the initial magnification deformation occurs from the stage before the substrates 210 and 230 are bonded. Therefore, the initial magnification deformation of the substrates 210 and 230 can be known before the lamination of the substrates 210 and 230 is started. For example, the control unit 150 can also obtain information related to the initial magnification deformation from the pre-processing device for manufacturing the substrates 210 and 230.

[0119] Adsorption factor deformation is deformation generated in the substrate 210, 230 when the substrate 210, 230 with deformation such as warping is attached or adsorbed to a flat holding member. If the warped substrate 210, 230 is adsorbed and held on the flat substrate holder 220, 240, or lower stage 332, the substrate 210, 230 is deformed to imitate the shape of the holding surface of the flat substrate holder 220, 240, or lower stage 332. Here, if the substrate 210, 230 changes from a warped state to a state imitating the shape of the holding surface of the substrate holder 220, 240, or lower stage 332, the deformation amount of the substrate 210, 230 changes compared to before being held.

[0120] As a result, the deformation amount of the circuit area 216 on the surface of the substrate 210, 230 relative to the design specification changes compared to before the holding. The change in the deformation amount of the substrate 210, 230 varies depending on the structure of the circuit area 216 and other structures formed on the substrate 210, 230, the process for forming the structure, the size of the warping of the substrate 210, 230 before holding, etc. In the case where the substrate 210, 230 has deformation such as warping, the size of the adsorption factor deformation can be calculated based on the state of the deformation including the warping amount and warping shape of the substrate 210, 230 by investigating the correlation between the deformation and the adsorption factor deformation in advance.

[0121] The lamination process magnification deformation is a change in the magnification deformation newly generated due to the deformation generated in the substrates 210 and 230 during the lamination process. Fig.19 , Fig. 20 and Fig.21 FIG. 2 is a partially enlarged view showing the bonding process of substrates 210 and 230 on a substrate holder 240 for the fixed side having a flat holding surface. Fig.19 , Fig. 20 and Fig.21 , an area Q near a boundary K between a contact area where the substrates 210 and 230 are in contact with each other and a non-contact area where the substrates 210 and 230 are separated from each other and then bonded together is shown in an enlarged manner during the bonding process using the bonding unit 300.

[0122] like Fig.19 As shown, in the process that the contact area of ​​the substrates 210 and 230 that are partially in contact with each other expands from the center to the periphery, the boundary K moves from the center side to the periphery side of the substrates 210 and 230. Near the boundary K, when the substrate 210 that is held by the substrate holder 220 is released, it is stretched due to the ambient gas sandwiched between the substrate 230, more specifically, due to the air resistance when the air sandwiched between the substrate 230 is driven out. More specifically, at the boundary K, with respect to the center plane in the thickness direction of the substrate 210, the substrate 210 is stretched on the lower surface side of the substrate 210 in the figure, and the substrate 210 is contracted on the upper surface side of the figure.

[0123] As a result, as shown by the dotted line in the figure, the outer end of the area bonded to the substrate 230 in the substrate 210 is deformed in such a manner that the positional deviation of the circuit area 216 on the surface of the substrate 210 relative to the design specification is enlarged relative to the substrate 230. Therefore, as shown by the deviation represented by the dotted line in the figure, a positional deviation caused by the difference in the stretching amount of the substrate 210, that is, the ratio of deformation, occurs between the lower substrate 230 held by the substrate holder 240 and the upper substrate 210 released from the holding by the substrate holder 220.

[0124] Moreover, if Fig. 20 As shown in FIG. 1 , if the substrates 210 and 230 are in contact with each other and attached to each other in the above state, the magnification deformation of the substrate 210 is fixed. Fig.21 As shown, the amount of stretching of the substrate 210 fixed by lamination accumulates as the boundary K moves toward the outer periphery of the substrates 210 and 230 .

[0125] The amount of the above-mentioned lamination process factor deformation can be calculated based on physical quantities such as the rigidity of the laminated substrates 210 and 230, the viscosity of the ambient gas sandwiched by the substrates 210 and 230, and the like. In addition, the amount of displacement caused by laminating substrates manufactured in the same batch as the laminated substrates 210 and 230 can be measured and recorded in advance, and the recorded measured value can be obtained by the control unit 150 as information related to the lamination process factor deformation caused by lamination of the substrates 210 and 230 of the batch. In addition, in the present embodiment, the lamination process includes a process from when the substrates 210 and 230 partially contact each other until the expansion of the contact area is completed.

[0126] Fig. 22 It means that due to the use Figures 19 to 21 Schematic diagram of positional offset on the stacked substrate 290 caused by the ratio deformation generated by the described bonding method. The arrow in the figure is a vector indicating the positional offset of the substrate 230 on the fixed side when the substrate 210 on the release side is used as a reference. Its direction indicates the direction of the positional offset, and its length indicates the magnitude of the positional offset. The offset shown in the figure has an offset that increases radially from the center point of the stacked substrate 290 toward the surface direction. In addition, the ratio deformation shown in the figure includes: the initial ratio deformation and the adsorption ratio deformation generated before bonding the substrates 210 and 230, and the bonding process ratio deformation generated during the bonding process of the substrates 210 and 230.

[0127] In addition, by using Figures 19 to 21 In the described bonding method, when bonding the substrates 210 and 230, the substrate holder 220 releases the holding of the substrate 210 while maintaining the holding of the substrate 230 by the substrate holder 240. Therefore, at the moment of bonding the substrates 210 and 230, the shape of the held substrate 230 is fixed, and the substrate 210 whose holding is released is bonded while deforming. Therefore, for the substrate 230 bonded in a fixed state, the bonding process magnification deformation may not be considered, but for the substrate 210 whose holding is released, the bonding process magnification deformation is preferably considered.

[0128] In a case where the substrate 230 on the fixed side is held in a deformed state due to the shape of the substrate holder 240, etc., for the substrate 210 that has been released from the hold, it is preferred to consider both the bonding process factor deformation and the adsorption factor deformation, and it is further preferred to also consider deformation such as the adsorption factor deformation caused by the substrate 210 imitating the shape of the deformed substrate 230.

[0129] In this way, when using Figures 19 to 21In the described bonding method, the final rate deformation difference of the substrates 210 and 230 after bonding is formed by superimposing the difference in the initial rate deformation initially possessed by the substrates 210 and 230, the difference in the adsorption rate deformation generated when the substrates 210 and 230 are held on the substrate holders 220, 240, etc., and the bonding process rate deformation of the substrate 210 that is released during the bonding process.

[0130] As mentioned above, when using Figures 19 to 21 The described method relates the positional deviation generated in the stacked substrate 290 formed by stacking the substrates 210 and 230 to the difference in initial factor deformation, the difference in adsorption factor deformation, and the difference in bonding process factor deformation. In addition, the factor deformation generated in the substrates 210 and 230 is related to deformation of the substrates such as warping.

[0131] Moreover, the difference in initial rate strain, adsorption rate strain, and bonding process rate strain can be estimated by measurement and calculation before bonding, as described above. Therefore, a countermeasure can be taken in advance to correct the difference based on the final rate strain difference estimated for the bonded substrates 210 and 230 after bonding.

[0132] As an example of a countermeasure, it is conceivable to select a substrate holder having a holding surface curvature capable of correcting the final difference in magnification factor strain from the plurality of substrate holders 240 for the fixed side. Fig.23 This is a partially enlarged view showing a bonding process of the substrates 210 and 230 on the substrate holder 240 when the fixed-side substrate holder 240 having a curved holding surface is used to correct the magnification distortion caused by air resistance.

[0133] like Fig.23 As shown in the figure, the holding surface 241 of the substrate holder 240 for the fixed side is curved. When the substrate 230 is adsorbed on the holding surface 241 of such a shape, in the state where the substrate 230 is curved, compared with the center portion A in the thickness direction of the substrate 230 shown by the dashed line in the figure, on the upper surface of the substrate 230 in the figure, i.e., the front surface, the shape of the surface of the substrate 230 changes to expand in the surface direction from the center toward the peripheral portion. In addition, on the lower surface of the substrate 230 in the figure, i.e., the back surface, the shape of the surface of the substrate 230 changes to shrink in the surface direction from the center toward the peripheral portion.

[0134] In this way, by holding the substrate 230 on the substrate holder 240, the upper surface of the substrate 230 in the figure is enlarged compared with the flat state of the substrate 230. By changing the shape in this way, the difference in final magnification deformation with other substrates 210, that is, the positional deviation caused by the difference can be corrected. In addition, by preparing a plurality of substrate holders 240 having different curvatures of the curved holding surfaces 241, the correction amount can be adjusted by selecting the substrate holder 240 having the holding surface 241 with a curvature such that the positional deviation amount caused by the final magnification deformation difference is less than a predetermined threshold value.

[0135] exist Fig.23 In the embodiment of the present invention, the holding surface 241 of the substrate holder 240 has a shape that is raised in the center. Alternatively, the substrate 230 may be held by preparing a substrate holder 240 that is recessed in the center relative to the peripheral portion of the holding surface 241, thereby reducing the magnification of the bonding surface of the substrate 230 and adjusting the positional deviation of the circuit area 236 formed on the bonding surface relative to the design specification.

[0136] Above, refer to Figures 19 to 22 , the magnification deformation in the linear deformation included in the plane deformation generated in the bonded substrates 210 and 230, especially the magnification deformation during the bonding process, is described. Fig.23 , an example of a countermeasure for correcting the difference based on the final magnification strain difference after bonding inferred from the bonded substrates 210 and 230. As another example of the countermeasure, the holding surface of the lower worktable 332 of the bonding unit 300 may be deformed by an actuator.

[0137] Next, among the nonlinear strains included in the planar strains generated in the bonded substrates 210 and 230 , strains due to anisotropy due to the crystal orientation of the substrates 210 and 230 , that is, strains due to crystal anisotropy will be described.

[0138] Fig.24 is a model showing the relationship between the crystal orientation and Young's modulus in the silicon single crystal substrate 208. Fig.24As shown, in the silicon single crystal substrate 208 with the (100) plane as the surface, in the XY coordinates with the direction opposite to the direction of the notch 214 relative to the center set to 0°, the Young's modulus is as high as 169 GPa in the 0° direction and the 90° direction, and as low as 130 GPa in the 45° direction. Therefore, in the substrates 210 and 230 made using the silicon single crystal substrate 208, an uneven distribution of bending rigidity is generated in the circumferential direction of the substrates 210 and 230. That is, the bending rigidity of the substrates 210 and 230 is different depending on the direction of travel when the bonding wave travels from the center of the substrates 210 and 230 toward the peripheral portion. The bending rigidity indicates the ease of deformation relative to the force of bending the substrates 210 and 230, and can also be used as an elastic modulus.

[0139] Fig.25 is a model showing the relationship between the crystal orientation and Young's modulus in the silicon single crystal substrate 209. Fig.25 As shown, in the silicon single crystal substrate 209 with the (110) plane as the surface, in the XY coordinates with the direction opposite to the direction of the notch 214 relative to the center being 0°, the Young's modulus in the 35.3° direction is the highest at 188 GPa, and the Young's modulus in the 0° direction is the second highest at 169 GPa. Moreover, the Young's modulus in the 90° direction is the lowest at 130 GPa. Therefore, in the substrates 210 and 230 manufactured using the silicon single crystal substrate 209, an uneven and complex distribution of bending rigidity is generated in the circumferential direction of the substrates 210 and 230.

[0140] Thus, in the substrates 210 and 230 using either of the silicon single crystal substrates 208 and 209 having different crystal anisotropy, a non-uniform distribution of bending rigidity occurs in the circumferential direction. Figures 19 to 21 The magnitude of the deformation produced during the bonding process described is different. Specifically, the magnitude of the deformation in the area with lower rigidity is smaller than that in the area with higher rigidity. Figures 19 to 21 In the laminated substrate 290 manufactured by laminating the substrates 210 and 230 by the described method, non-uniform positional shifts of the circuit regions 216 and 236 occur in the circumferential direction of the laminated substrate 290. Positional shifts between bonded substrates due to deformation caused by crystal anisotropy are caused by the crystal anisotropy of the substrate 230 on the release side.

[0141] Fig.26The schematic diagram shows a plurality of circuit regions 216 and 236 on the surface of the substrate 610 and 630, which are pre-corrected so that the positional deviation on the laminated substrate 290 caused by the magnification deformation due to air resistance and the deformation due to crystal anisotropy generated during lamination is less than a predetermined threshold value. The substrate 610 is the substrate on the release side of the lamination section 300, and the substrates 610 and 630 are formed by using Fig.24 The illustrated silicon single crystal substrate 208 is formed.

[0142] exist Fig.23 In the embodiment, as a method of pre-correcting the rate deformation caused by air resistance, a substrate holder having a curved holding surface 241 is selected as the substrate holder 240 for the fixed side. However, a structure in which the processing and operation of the substrate holder 220, 240 or the upper workbench 322, the lower workbench 332 are easier is a structure in which their holding surfaces are flat. Therefore, in the present embodiment, instead of the method of correcting the method of using the substrate holder 240 for the fixed side with a curved holding surface 241, the configuration of the plurality of circuit areas 216 formed on the surface of the substrate 610 on the release side is pre-corrected, thereby making the positional deviation on the stacked substrate 290 caused by the rate deformation caused by air resistance and the deformation caused by crystal anisotropy generated during bonding less than a predetermined threshold.

[0143] Regarding the substrate 630 on the fixed side, since it is kept in a fixed state during lamination, it is predicted that no magnification deformation caused by air resistance and deformation caused by crystal anisotropy will occur. Therefore, in the substrate 630, when multiple circuit regions 236 are formed on the entire substrate 630 by repeatedly exposing using the same mask, the exposure region map (ShotMap) is not corrected, and multiple circuit regions 236 are formed on the entire substrate 630 at equal intervals.

[0144] On the other hand, regarding the substrate 610 on the release side, it is predicted that the magnification deformation caused by air resistance and the deformation caused by crystal anisotropy will be generated when it is released during lamination. Therefore, in the case where multiple circuit areas 216 are formed on the entire substrate 610 by repeatedly exposing using the same mask, the exposure area map is corrected so that the positional offset caused by the magnification deformation caused by air resistance and the deformation caused by crystal anisotropy is less than a predetermined threshold value, and the intervals between the multiple circuit areas 216 are gradually narrowed from the center of the substrate 610 toward the peripheral portion within the entire range, and the intervals in the 0° direction and the 90° direction are narrower than the interval in the 45° direction. Thus, even if the holding surface 241 of the substrate holder 240 for the fixed side is flat, the positional offset on the stacked substrate 290 caused by the magnification deformation caused by air resistance and the deformation caused by crystal anisotropy that will occur during lamination can be suppressed to less than a predetermined threshold value.

[0145] Next, nonlinear strain included in the planar strain generated in the bonded substrates 210 and 230 will be described. Fig. 27 The diagram schematically shows positional deviation on the stacked substrate 290 caused by nonlinear deformation when the substrate 210 on the release side has local curvature instead of overall warpage relative to the substrate 230 fixed to the substrate holder 240 in a flat state. Fig. 27 The positional deviation caused by the nonlinear deformation shown does not include Fig. 22 The position shift caused by the magnification deformation shown in FIG. Fig. 27 The positional deviation caused by the nonlinear deformation in the substrate 210 shown may show different results depending on the protrusion amount of the protruding member 250 of the substrate holder 220 that holds the substrate 210.

[0146] The arrow in the figure is a vector indicating the positional deviation of the substrate 230 on the fixed side when the substrate 210 on the release side is used as a reference. Its direction indicates the direction of the positional deviation, and its length indicates the magnitude of the positional deviation. Fig. 27 As shown, the positional offset caused by the nonlinear deformation due to local bending in the laminated substrate 290 shows the same trend in the first quadrant where X is positive and Y is positive, i.e., the 45° direction, and in the third quadrant where X is negative and Y is negative, i.e., the 225° direction, and in the second quadrant where X is negative and Y is positive, i.e., the 315° direction, and in the fourth quadrant where X is positive and Y is negative, i.e., the 135° direction, respectively. Different trends are shown in the first and third quadrants and in the second and fourth quadrants. In addition, there is no regular distribution of the positional offset amount along the radial direction from the center of the laminated substrate 290. Fig. 27It can be seen that the positional offset caused by nonlinear deformation refers to the position of each structure of the substrates 210 and 230 after displacement relative to the designed position, which cannot be represented by linear transformation.

[0147] Nonlinear deformation is caused by the interaction of various important factors, but the main important factor is the reference Fig.24 and Fig.25 The crystal anisotropy of the silicon single crystal substrates 208 and 209 and the manufacturing process of the substrates 210 and 230 are described. Fig. 27 The positional deviation on the stacked substrate 290 shown is also the result of the superposition of nonlinear deformation caused by local warpage while nonlinear deformation caused by crystal anisotropy occurs. Figure 2 As described above, in the manufacturing process of the substrates 210 and 230, a plurality of structures are formed on the substrates 210 and 230. For example, as structures, a plurality of circuit regions 216 and 236, scribe lines 212 and 232, and a plurality of alignment marks 218 and 238 are formed on the substrates 210 and 230. In each of the plurality of circuit regions 216 and 236, as structures, in addition to wiring, protective films, etc. formed by photolithography technology, etc., connection parts such as pads and bumps that serve as connection terminals when the substrates 210 and 230 are electrically connected to other substrates 230 and 210, lead frames, etc. are provided. The construction and arrangement of these structures, that is, the structure of the structures, affects the rigidity distribution and internal surface stress distribution in the plane of the substrates 210 and 230. If the rigidity distribution and internal surface stress distribution are uneven, local bending occurs in the substrates 210 and 230.

[0148] The structures of these structures may also be different for each substrate 210, 230, or may be different for each type of substrate 210, 230 such as a logic chip, a CIS chip, or a storage chip. In addition, even if the manufacturing process is the same, it is considered that the structure of the structure is slightly different depending on the manufacturing device, so the structure of these structures may also be different for each manufacturing batch of the substrates 210, 230. In this way, the structures of the multiple structures formed on the substrates 210, 230 can be different for each substrate 210, 230, for each type of substrate 210, 230, for each manufacturing batch of the substrates 210, 230, or for each manufacturing process of the substrates 210, 230. Therefore, the rigidity distribution within the surface of the substrates 210, 230 is also different. Therefore, the bending state of the substrates 210, 230 generated during the manufacturing process and the bonding process is also different.

[0149] When a pair of substrates 210 and 230 are bonded together, if local bending occurs in the substrate 210 on the release side, the distance between the portion where the local bending occurs and the substrate 230 when bonding with the other substrate 230 may become larger than the portion where the local bending does not occur. For example, warping such as stretching of the bonding surface may occur in the substrate 210 on the release side. Therefore, in the portion where the local bending occurs, the progress of the bonding wave is slower than in the portion where the local bending does not occur, and wrinkles are concentrated in the portion where the local bending occurs in the substrate 210 on the release side, and for this reason, nonlinear deformation occurs in the bonded laminated substrate 290. That is, there is a correlation between local bending and nonlinear deformation, and the portion where the local bending of the substrate 210 on the release side before bonding becomes larger, the nonlinear deformation generated in the laminated substrate 290 after bonding also becomes larger. However, this causal relationship applies to the case where there is no deformation other than the deformation caused by local bending. On the other hand, even when the bonded substrates 210 and 230 have local curvature, nonlinear strain caused by the local curvature may be offset by strain due to, for example, crystal anisotropy.

[0150] In the case where the substrate 230 on the fixed side of the pair of substrates 210 and 230 is partially bent before bonding, the entire back side of the bonding surface is maintained in a state of being fixed by adsorption by the substrate holder 240 or the like, so that nonlinear deformation due to the local bending of the substrate 230 on the fixed side does not occur, and nonlinear positional offset due to the local bending of the substrate 230 on the fixed side does not occur between the substrates 210 and 230 after bonding. However, the substrate 230 on the fixed side may produce adsorption magnification deformation, but such deformation is smaller than the deformation produced in the substrate 210 on the release side, and its influence is almost negligible. On the other hand, in the case where the substrate 210 on the release side is partially bent before bonding, positional offset due to nonlinear deformation occurs between the bonded pair of substrates 210 and 230 for the above-mentioned reasons.

[0151] In order to suppress such positional deviation caused by nonlinear deformation, the control unit 150 obtains at least information related to the local bending of the substrate 210 on the releasing side before the bonding of the substrates 210 and 230, and pre-sets the initial bonding area 803 of the substrate 210 on the releasing side based on the characteristics of the local bending of the substrate 210 contained in the acquired information, and maintains the substrate holder 220 holding at least the outermost area of ​​the substrate 210 until the bonding of the pre-set initial bonding area 803 is detected by expanding the bonding area 801 from near the center of the substrates 210 and 230 toward the periphery.

[0152] For example, as in the present embodiment, assuming that the local curvature in the substrate 210 increases gradually in the radial direction from the center side to the outer peripheral side of the substrate 210 at least partially, until the preset initial bonding area 803 of the substrate 210 is bonded, the state where the local curvature and the non-local curvature in the outermost peripheral area of ​​the substrate 210 are both held by the substrate holder 220. Thus, within the entire range of the outermost peripheral area of ​​the substrate 210, the distance from the other bonded substrate 230 is kept constant within a predetermined range.

[0153] During the period until the predetermined initial bonding area 803 is bonded, a warp of the same magnitude is forcibly formed throughout the entire outermost area of ​​the substrate 210, thereby suppressing the difference in the extent of the bonding wave between the portion of the substrate 210 where local bending occurs and the portion where local bending does not occur.

[0154] In the region where the initial bonding region 803 overlaps with the portion where the local bending occurs, the difference in the extent of the bonding wave can be suppressed, so the greater the degree of overlap, the greater the effect of suppressing the nonlinear positional offset generated between the bonded substrates 210 and 230. Therefore, the control unit 150 pre-sets the initial bonding region 803 of the substrate 210 on the release side so that the amount of nonlinear positional offset generated between the bonded substrates 210 and 230 is less than a predetermined threshold.

[0155] As described above, information on local warping of the substrate 210 is included in information on deformation generated in the substrate 210. The information on deformation generated in the substrate 210 includes information on overall warping in which the entire substrate 210 is bent with substantially the same curvature, and information on local warping in which a part of the substrate 210 has a change in local curvature, that is, local bending.

[0156] The information related to the overall warping includes: information obtained by measuring the overall bending of the substrate 210, such as the overall bending characteristics of the substrate 210, such as the size of the overall warping, the direction of the warping, the size of the bend, the direction of the bend, etc.; and information related to the cause of the overall warping in the substrate 210, such as the crystal anisotropy of the substrate 210, the manufacturing process, the type of substrate 210, and the structure of the structure formed on the substrate 210.

[0157] The information related to the local warping includes: information obtained by measuring the local warping of the substrate 210, such as the characteristics of the local warping, such as the size of the local warping of the substrate 210, the direction of the warping, the part of the warping, the amplitude of the warping, the size of the bend, the direction of the bend, the amplitude of the bend, the part of the bend, the internal stress, and the stress distribution; and information related to the cause of the local warping in the substrate 210, such as the crystal anisotropy of the substrate 210, the manufacturing process, the type of the substrate 210, and the structure of the structure formed on the substrate 210.

[0158] The control unit 150 may also obtain information related to the deformation generated in the substrate 210 from a pre-processing device such as an exposure device and a film forming device used in a process performed before the substrate bonding device 100. In addition, in the substrate bonding device 100, the information may also be obtained from, for example, a pre-aligner 500 used in a process performed before the bonding unit 300. The control unit 150 outputs information determined based on the obtained information to at least one of the conveying unit 140, the pre-aligner 500, and the bonding unit 300.

[0159] In the present embodiment, for example, in the pre-processing device, local warping is actually measured as an example of deformation of the substrates 210 and 230 . Fig.28 This figure explains the method of measuring deflection and calculating warpage. Fig.28 In the method, first, the deflection of the substrate 210, 230 as the target substrate is measured. Specifically, while the center of the surface direction of the back side of the substrate 210, 230 is supported and rotated around the center under gravity, the surface or back side of the substrate 210, 230 is observed by a non-contact distance meter such as a microscope, and the position of the surface or back side is measured based on the distribution of distance information obtained by the automatic focusing function of the optical system of the microscope.

[0160] Thus, the deflection amount including the size and direction of the deflection of the substrates 210 and 230 under gravity can be measured. The deflection amount of the substrates 210 and 230 is calculated based on the displacement of the position of the surface or back surface of the substrates 210 and 230 in the thickness direction when the supported center is used as a reference. Next, the control unit 150 obtains information on the deflection amount of the substrates 210 and 230 and decomposes it into a linear component and a nonlinear component along the radial direction from the center of the substrate. Fig.28 In FIG. 1 , the linear component of the deflection amount of the substrates 210 and 230 is expressed in a parabola as the average deflection (A), and the nonlinear component is expressed in a wave line as the amplitude of the deflection at the periphery (B).

[0161] Next, the deflection of the bare silicon serving as the reference substrate is measured. Bare silicon is a substrate 210, 230 without a structure formed thereon, and can be regarded as a substrate 210, 230 without warping. However, in the case where even the bare silicon has some warping, it is preferable to calculate the deflection amount serving as a reference based on the deflection measurement of the front and back of the bare silicon. The deflection amount of the bare silicon is measured under the same measurement conditions as for the substrates 210, 230. Furthermore, the control unit 150 obtains information on the deflection amount of the bare silicon and decomposes it into a linear component ( Fig.28 (A)) and nonlinear components ( Fig.28 (B)).

[0162] Then, the amplitude of the deflection at the outer periphery of the bare silicon is subtracted from the amplitude of the deflection at the outer periphery of the substrates 210 and 230. Thus, the nonlinear component of the warpage amount of the substrates 210 and 230, which can be regarded as a measurement value under zero gravity, can be calculated. Fig.28 In the calculation, the nonlinear component of the warpage of the substrates 210 and 230 is expressed as a wave line as the amplitude (B) of the warpage at the periphery, which corresponds to the above-mentioned local warpage. In addition, the reason why the warpage, which is the deformation measured under zero gravity, can be calculated by this method is that the deformation due to the dead weight included in the deflection, which is the deformation measured under gravity, is substantially subtracted by the above-mentioned subtraction.

[0163] In addition, by subtracting the average warpage of the bare silicon from the average warpage of the substrates 210 and 230, a linear component of the warpage of the substrates 210 and 230, which can be regarded as a measured value under zero gravity, can be calculated, and this corresponds to the above-mentioned overall warpage. Fig.28 In FIG. 1 , the linear component of the warpage of the substrates 210 and 230 is represented in a parabolic shape as the average warpage (A).

[0164] Finally, the condition of the substrate 210 on the release side during bonding is reflected. Specifically, the amplitude of the warping at the periphery of the substrate 210 is changed by taking into account the downward posture of the surface of the substrate 210 on the release side and the direction of gravity, thereby calculating the amplitude of the warping at the periphery of the substrate 210 when the center of the surface direction of the substrate 210 is supported and measured as described above as a predicted value.

[0165] Based on the amplitude of the warping at least at the outer periphery of the release-side substrate 210, among the amplitudes of the warping at the outer periphery of each of the substrates 210 and 230 calculated as information related to the local warping of the release-side substrate 210 and the fixed-side substrate 230, the control unit 150 presets the initial bonding area 803 of the release-side substrate 210. The initial bonding area 803 may be preset based on, for example, the maximum value or average value of the amplitude of the warping at the outer periphery, or may be preset based on the occurrence position of the warping in the bonding surface of the substrate 210 and the size of the warping.

[0166] As described above, the local curvature of the substrates 210 and 230 may be different for each substrate 210 and 230, for each type of the substrates 210 and 230, for each manufacturing batch of the substrates 210 and 230, or for each manufacturing process of the substrates 210 and 230. Therefore, the control unit 150 may pre-set the initial bonding area 803 of the substrate 210 whenever the substrates 210 and 230 are bonded together, may pre-set it for each type of the substrates 210 and 230, may pre-set it for each manufacturing batch of the substrates 210 and 230, or may pre-set it for each manufacturing process of the substrates 210 and 230. In addition, after the initial bonding area 803 is set for the first substrates 210 and 230 included in the manufacturing batch or the same type, the same initial bonding area 803 may be applied to the substrates 210 and 230 in the same batch or the same type.

[0167] In addition, the residual stress of the substrates 210 and 230 may be measured by Raman scattering or the like while the substrates 210 and 230 are forcibly flattened by adsorbing the substrates 210 and 230 by the substrate holder 240 or the like, and the residual stress may be used as information related to the local curvature of the substrates. In addition, the local curvature of the substrates 210 and 230 may also be measured in the pre-aligner 500.

[0168] On the other hand, instead of measuring the local curvature of the substrates 210 and 230, the control unit 150 may analytically acquire information related to the local curvature of the substrates 210 and 230, and at least infer the characteristics of the local curvature of the substrate 210 based on the acquired information, and pre-set the initial bonding area 803 of the substrate 210 based on the inferred characteristics of the local curvature of the substrate 210. In this case, based on the manufacturing process of the substrates 210 and 230, the structure and material of the structures such as the circuit regions 216 and 236 formed on the substrates 210 and 230, the type of the substrates 210 and 230, and the stress distribution in the substrates 210 and 230, the characteristics of the local curvature such as the size and direction of the warpage generated in the substrates 210 and 230 and the shape of the substrates 210 and 230 may be inferred. In addition, the manufacturing process of the substrates 210 and 230 generated in the process of forming the above-mentioned structure, that is, information related to the thermal history accompanying film formation, chemical processing such as etching, etc., can be used as information on the cause of warping, and the warping generated in the substrates 210 and 230 can be inferred based on this information.

[0169] Furthermore, when estimating the characteristics of the local curvature generated in the substrates 210 and 230, peripheral information such as the surface structure of the substrates 210 and 230, the thickness of the thin film stacked on the substrate 210, the tendency, deviation, order and conditions of the film forming apparatus such as the CVD apparatus used for film forming, etc., which are the causes of the local curvature generated in the substrates 210 and 230, can also be referred to. These peripheral information can also be re-measured for the purpose of estimating the characteristics of the local curvature.

[0170] Furthermore, in order to infer the characteristics of the local bending of the substrates 210 and 230, past data on the same substrates may be referred to, or an experiment of a hypothetical process may be conducted on substrates equivalent to the laminated substrates 210 and 230 to prepare in advance data on the relationship between the local bending, i.e., the amount of warping, and nonlinear deformation, the relationship between the difference in the amount of warping and the difference in nonlinear deformation between the two substrates, or the combination of the amount of warping when the difference in nonlinear deformation between the two substrates, i.e., the amount of positional deviation is below a threshold. Furthermore, the amount of warping may be analytically calculated based on the film formation structure and film formation conditions of the laminated substrates 210 and 230 by the finite element method or the like to prepare data.

[0171] Furthermore, the deformation amount of the substrates 210 and 230 may be measured outside the substrate bonding apparatus 100, or a device for measuring the deformation of the substrates 210 and 230 may be assembled inside the substrate bonding apparatus 100 or a system including the substrate bonding apparatus 100. Furthermore, internal and external measuring devices may be used simultaneously to increase the number of measuring items.

[0172] Here, use Fig.29The advantage of a larger initial bonding area will be described. Fig.29 The diagram is a diagram for explaining the comparison between the process (A) of bonding the substrates 210 and 230 using the substrate holder 820 having the outer peripheral ventilation path 822 and the process (B) of bonding the substrates 210 and 230 using the substrate holder 220 having the outermost peripheral ventilation path 622 .

[0173] like Fig.29 As shown, the peripheral ventilation path 822 of the substrate holder 820 is located inside the outermost peripheral ventilation path 622 of the substrate holder 220. In this case, as shown in FIG. Fig.29 As shown in the left figures of (A) and (B), the outer shape of the initial bonding area 803 bonded while holding the outermost peripheral area of ​​the substrate 210 can be set so that the substrate holder 220 is larger than the substrate holder 820. Therefore, even if the substrate holder 220 does not change the structure of the substrate holder 220 itself, it can correspond to the size of various initial bonding areas.

[0174] And, if Fig.29 As shown in the comparison of the right sides of (A) and (B), when the peripheral ventilation path 822 and the outermost peripheral ventilation path 622 are released after the initial bonding area is bonded, the local curvature generated in the substrate 210 needs to be restored due to the release. In this case, the substrate 210 held by the substrate holder 220 has been bonded to the side closer to the periphery, so the size C2 of the curvature is smaller than the size C1 of the curvature of the substrate 210 held by the substrate holder 820, and the effect of bonding on the deformation is also smaller. Therefore, by making the initial bonding area larger, the effect of the local curvature of the substrate 210 on the deformation of bonding can be suppressed to a small extent.

[0175] In addition, in the main embodiment, the control unit 150 predetermines a predetermined number of initial bonding areas 803, and a corresponding number of observation holes 601, observation windows 361, detectors 341, etc. are pre-set in the substrate holder 220 and the bonding unit 300. Alternatively, when the control unit 150 predetermines an initial bonding area 803 of an arbitrary size based on the local bending characteristics of the substrate 210 on the release side, continuous linear observation holes and windows are pre-set in the substrate holder 220 and the bonding unit 300, and line sensors as detectors are pre-set at positions corresponding to them. Thus, the observation unit 345 can observe the bonding of the initial bonding area 803 of an arbitrary size.

[0176] Fig.30 1 is a schematic top view of a substrate holder 920 according to another embodiment. Fig.31 is Fig.30A schematic cross-sectional view of a substrate holder 920 holding a substrate 210 when the substrate holder 920 is cut along line III-III, which is bent at the center of the schematic top view. In the present embodiment, a substrate holder 920 is used instead of the substrate holder 220 for the release side used in the main embodiment. In addition, the substrate holder 240 for the fixing side has the same structure as that used in the main embodiment, and therefore repeated descriptions are omitted. In addition, for the same structure as that of the substrate holder 220 in the substrate holder 920, the same or corresponding reference numerals are used, and repeated descriptions are omitted. In addition, in Fig.30 In order to clarify the description, illustration of the plurality of support pins 924 is omitted.

[0177] The main body 929 of the substrate holder 920 has four annular support parts 925, 926, 927, and 928 formed concentrically with the center of the substrate holder 920 on the holding surface 921, and a plurality of linear support parts 922 formed radially from the center of the substrate holder 920 on the holding surface 921. The four support parts 925, 926, 927, and 928 are arranged in sequence from the center side of the substrate holder 920. The inner peripheral surface of the support part 925 is aligned with the inner peripheral surface of the cylindrical recessed part 923 provided in the approximate center of the main body 929, and surrounds the periphery of the recessed part 923 on the holding surface 921. The support part 928 has an outer shape that is substantially the same as the outer shape of the substrate 210 held by the substrate holder 920. The support portion 927 is located slightly closer to the center side than the support portion 928 on the holding surface 921, and forms an annular groove together with the support portion 928 on the outermost peripheral side of the substrate holder 920. The support portion 926 is located between the support portion 925 and the support portion 927 in the radial direction of the substrate holder 920, and divides the area between the support portion 925 and the support portion 927 into the inner peripheral side and the outer peripheral side. The plurality of support portions 922 are formed to intersect with the support portion 925, etc., and divide the area between the support portion 925 and the support portion 926, the area between the support portion 926 and the support portion 927, and the area between the support portion 927 and the support portion 928 into a plurality of areas.

[0178] The main body 929 also has an inner peripheral ventilation path 931, an outer peripheral ventilation path 932, and an outermost peripheral ventilation path 933. The inner peripheral ventilation path 931 is located between the support portion 925 and the support portion 926 on the holding surface 921 and each of the multiple fan-shaped areas isolated from each other by the multiple support portions 922, and has a plurality of suction holes opened at a location where the multiple support pins 924 are not formed at one end. The other end of the inner peripheral ventilation path 931 is selectively connected to the negative pressure source 733 and the open end 743 via the control valve 723 outside the substrate holder 920. The outer peripheral ventilation path 932 is located between the support portion 926 and the support portion 927 on the holding surface 921 and each of the multiple fan-shaped areas isolated from each other by the multiple support portions 922, and has a plurality of suction holes opened at a location where the multiple support pins 924 are not formed at one end. The other end of the outer peripheral ventilation path 932 is selectively connected to the negative pressure source 735 and the open end 745 via the control valve 725 outside the substrate holder 920. The outermost peripheral ventilation path 933 is located between the support portion 927 and the support portion 928 on the holding surface 921 and each of the plurality of fan-shaped regions isolated from each other by the plurality of support portions 922, and has a plurality of suction holes opened at a portion where the plurality of support pins 924 are not formed at one end. The other end of the outermost peripheral ventilation path 933 is selectively connected to the negative pressure source 737 and the open end 747 via the control valve 727 outside the substrate holder 920. Hereinafter, the region on the radial central side within the surface of the substrate 210 and the region adsorbed between the support portion 925 and the support portion 926 of the substrate holder 920 is sometimes referred to as the inner peripheral region of the substrate 210. In addition, the radially outer region within the surface of the substrate 210 and the region sucked between the support portions 227 and 228 of the substrate holder 920 is sometimes referred to as the outermost peripheral region of the substrate 210. In addition, the region between the inner peripheral region and the outermost peripheral region within the surface of the substrate 210 and the region sucked between the support portions 226 and 227 of the substrate holder 920 is sometimes referred to as the outer peripheral region of the substrate 210.

[0179] In order to be able to adsorb the outer peripheral area and the outermost peripheral area of ​​the substrate 210, a plurality of suction holes at one end of the outer peripheral ventilation path 932 and the outermost peripheral ventilation path 933 are provided at the outer periphery and the outermost periphery of the substrate holder 920. Fig.31 As shown in FIG. 1 , the peripheral ventilation path 932 and the outermost peripheral ventilation path 933 are formed by deviating from each other in the thickness direction and extending in the surface direction inside the substrate holder 920, so that the other end is arranged close to the center side of the substrate holder 920. Thus, the substrate holder 920 can also be applied to a vacuum plate or a substrate bonding workbench, which holds the substrate holder 920 and concentrates air pipes for providing suction or exhaust to each ventilation path of the substrate holder 920 at the center of the holding surface of the substrate holder 920.

[0180] The control valves 723, 725, and 727 selectively connect the inner circumferential ventilation path 931, the outer circumferential ventilation path 932, and the outermost circumferential ventilation path 933 to the negative pressure sources 733, 735, and 737, respectively, under the control of the control unit 150. When the substrate 210 is placed on the support unit 925 and the plurality of support pins 924, the control valves 723, 725, and 727 connect the inner circumferential ventilation path 931, the outer circumferential ventilation path 932, and the outermost circumferential ventilation path 933 to the negative pressure sources 733, 735, and 737, respectively, and negative pressure acts on the plurality of air intake holes of the inner circumferential ventilation path 931, the outer circumferential ventilation path 932, and the outermost circumferential ventilation path 933. As a result, the spaces between the support portions 925 and 926, the spaces between the support portions 926 and 927, and the spaces between the support portions 927 and 928, which are divided into a plurality of spaces in the circumferential direction by the plurality of support portions 922, are decompressed, and the substrate 210 is adsorbed to the substrate holder 920. On the other hand, when the control valves 723, 725, 727 connect the inner peripheral ventilation path 931, the outer peripheral ventilation path 932, and the outermost peripheral ventilation path 933 to the open ends 743, 745, 747, respectively, from the state where the substrate 210 is adsorbed to the substrate holder 920, the adsorption of the substrate 210 by the substrate holder 920 is released.

[0181] In this way, the inner peripheral ventilation path 931, the outer peripheral ventilation path 932 and the outermost peripheral ventilation path 933 are respectively combined with the control valves 723, 725, and 727 independently controlled by the control unit 150, and the multiple adsorption holes at one end of each are opened in each space isolated from each other by the support part 926, the support part 927 and the support part 928. Thus, under the control of the control unit 150, the substrate holder 920 can independently adsorb the inner peripheral area, the outer peripheral area and the outermost peripheral area of ​​the substrate 210 in the radial direction, and can independently release the adsorption. In other words, the substrate holder 920 has an inner peripheral adsorption area, an outer peripheral adsorption area and an outermost peripheral adsorption area that are isolated and independent from each other and arranged in a concentric circle along the radial direction. In addition, in addition to this, in the circumferential direction of each area, adsorption and release can also be performed independently from each other.

[0182] The main body 929 further comprises: four observation holes 901, 902, 903, 904, which are formed between the support portion 925 and the support portion 926 and between the support portion 926 and the support portion 927 on the holding surface 921 and at four locations where the plurality of support pins 924 are not formed, and penetrate the substrate holder 920 in the thickness direction; and an observation hole 905, which is formed between the support portion 927 and the support portion 928 on the holding surface 921 and penetrates the substrate holder 920 in the thickness direction. The five observation holes 901, 902, 903, 904, 905 are as shown in Fig.30 As shown in the schematic top view of FIG. 21 , the three observation holes 901, 902, and 903 are arranged at approximately equal intervals in sequence from the center side of the substrate holder 920 between the support portion 925 and the support portion 926 near the center of the substrate holder 920. The observation hole 904 is located on the outer peripheral side between the support portion 926 and the support portion 927. In addition, the observation holes 901 and the like are filled with a material that is transparent to the wavelength of the illumination light used when observing the substrate 210, and the two ends of the observation holes 901 and the like are smoothly formed together with the two planes of the substrate holder 920.

[0183] Fig.32 This is an explanatory diagram for explaining the process of bonding substrates 210 and 230 using substrate holder 920. The control unit 150 observes the expansion of bonding area 801 through observation hole 901 of substrate holder 920 etc. with the aid of observation unit 345. As bonding area 801 expands, the adsorption of the above-mentioned multiple adsorption areas is released in sequence from the central side to the peripheral side of substrate holder 920. In substrate holder 920, the timing of releasing the negative pressure of inner peripheral ventilation path 931, outer peripheral ventilation path 932 and outermost peripheral ventilation path 933 is preferably to keep the angle R between the part of substrate 210 standing up from the bonding area and the bonding area as constant as possible and to expand the bonding area. In this way, the deformation caused by air resistance can be kept constant and the nonlinearity of the deformation can be suppressed.

[0184] In particular, the substrate holder 920 has an inner peripheral ventilation path 931, an outer peripheral ventilation path 932, and an outermost peripheral ventilation path 933 from the inner periphery to the outer periphery, so R can be further maintained constant compared to the control by the inner peripheral ventilation path 621 and the outermost peripheral ventilation path 622 as in the substrate holder 220. In addition, R can be maintained constant by changing the protrusion amount of the protruding member 950 as the bonding area is expanded instead of increasing the number of ventilation paths or on the basis of this. In this case, the protrusion amount of the protruding member 950 itself can be actively changed, or the protrusion amount of the protruding member 950 itself can be passively changed through the substrates 210 and 230 by the upward thrust from the opposing substrate holder 240.

[0185] Here, the size of the initial bonding area 803 bonded while holding the outermost peripheral area of ​​the substrate 210 on the release side, the height of the protruding parts 250, 950 in the substrate holder 220, 920 on the release side, and the size of the adsorption area of ​​the substrate 210 adsorbed by the substrate holder 220, 920 on the release side are sometimes correlated. For example, the smaller the height of the protruding parts 250, 950 in the state where the substrate holder 220, 920 holds the substrate 210, the smaller the curvature of the convex shape near the center of the substrate 210 in the state where the substrate 210 is held, so the initial bonding area 803 becomes larger. As a result, the nonlinear deformation caused by local warping is sometimes reduced. In addition, the amount of deformation of the center of the substrate 210 on the release side into a convex shape due to the protruding parts 250, 950 becomes smaller, so the nonlinear deformation near the center of the substrate 210 is sometimes reduced.

[0186] In addition, as an example, if the adsorption area of ​​the substrate holder 220, 920 to the substrate 210 is set small, that is, the substrates 210 and 230 are bonded together while only the outer peripheral end side of the substrate 210 is held, the area of ​​the substrate 210 close to the substrate 230 becomes larger while the substrate 210 is held, and thus the initial bonding area 803 becomes larger. As a result, the nonlinear deformation caused by local warping is reduced, and the adsorption ratio deformation is reduced.

[0187] Fig.33 2 is an explanatory diagram for explaining how to change the setting of the initial bonding area according to the presence or absence of overall warping in the substrate 210 on the release side. Fig.33 In the table, a schematic curve diagram showing the relationship between the radial position of the bonded substrates and the positional offset generated between the bonded substrates is shown for four combinations of the case where there is no overall warping and the case where there is overall warping in the substrate 210 on the release side, the case where the initial bonding area is not formed, and the case where the initial bonding area is formed. Fig.33 In each of the graphs shown, the solid line represents the positional offset, and the dotted line represents the average magnification. More specifically, the average magnification is the magnification obtained by the least square method. In addition, the difference between the solid line and the dotted line in each graph represents the magnitude of the nonlinear deformation.

[0188] If the overall warpage of the substrate 210 on the release side is large, the factor strain caused by air resistance may increase from the center side toward the outer peripheral side of the substrate 210. In this case, in the substrate 210 with large overall warpage, the nonlinear strain increases on the outer peripheral side.

[0189] like Fig.33As shown in the upper left of the table, when there is no overall warpage in the substrate 210 on the release side, nonlinear deformation is not likely to occur even if the initial bonding area is not formed. However, strictly speaking, even in the substrate 210 without overall warpage, the magnification deformation caused by air resistance gradually changes within the surface of the substrate 210, so nonlinear deformation will also occur.

[0190] On the other hand, Fig.33 As shown in the lower left corner of the table, when there is no overall warping in the substrate 210 on the release side, for example, when the initial bonding area is formed by reducing the outermost peripheral adsorption area based on the substrate holder 220 or reducing the convex amount of the protruding part 250, sometimes the nonlinear deformation in the in-plane central area and the in-plane peripheral area of ​​the substrate 210 on the release side becomes larger, resulting in a positional offset caused by the nonlinear deformation.

[0191] In addition, if Fig.33 As shown in the upper right corner of the table, when there is overall warping in the substrate 210 on the release side and when the initial bonding area is not formed, the nonlinear deformation in the inner and outer peripheral areas of the surface of the substrate 210 on the release side sometimes becomes larger, resulting in positional displacement caused by the nonlinear deformation.

[0192] On the other hand, Fig.33 As shown in the lower right of the table, when there is overall warpage in the substrate 210 on the release side, when the initial bonding area is formed, nonlinear deformation may occur in the in-plane central area of ​​the substrate 210 on the release side, but the nonlinear deformation in the outer peripheral area of ​​the surface is alleviated, and the positional deviation caused by the nonlinear deformation is reduced as a whole. It is preferable to generate an initial bonding area of ​​a size suitable for the nonlinear deformation observed in the entire substrate 210.

[0193] As described above, when there is no overall warpage in the substrate 210 on the release side, it is sometimes preferable not to form the initial bonding area compared to forming the initial bonding area, and when there is overall warpage in the substrate 210 on the release side, it is sometimes preferable to expand the size of the initial bonding area. Therefore, the balance between the nonlinear deformation in the in-plane central area of ​​the substrate 210 on the release side and the nonlinear deformation in the in-plane peripheral area can also be considered, and the size of the initial bonding area can be set in a manner that the nonlinear deformation is reduced as a whole. For example, the size of the initial bonding area can also be set in a manner that at least one of the maximum value, average value, and 3σ (σ is the standard deviation) of the size of the nonlinear deformation represented by the difference between the solid line and the dotted line in each curve graph is less than a predetermined threshold.

[0194] In the above multiple embodiments, the substrate bonding device 100 can also execute a sequence of substrate bonding in the order of (1) to (6) below. (1) The inner peripheral area and the outermost peripheral area of ​​the substrate 210, or the inner peripheral area, the outer peripheral area and the outermost peripheral area of ​​the substrate 210 are adsorbed by the substrate holder 220, 920 on the release side. (2) EGA (enhanced, general, alignment) measurement is performed. (3) Parts of the substrates 210 and 230 are brought into contact with each other to form a bonding area 801. (4) The adsorption of the substrate 210 by the substrate holder 220, 920 on the release side is changed to only the outermost peripheral area of ​​the substrate 210. (5) Wait until the initial bonding area 803 pre-set by expanding the above-mentioned bonding area 801 is bonded. (6) Based on the detection of the bonding of the initial bonding area 803, the adsorption of the outermost peripheral area of ​​the substrate 210 by the substrate holder 220, 920 on the release side is also released, thereby releasing the retention of the substrate 210. When the substrates 210 and 230 are aligned with the substrate holder 220 adsorbing the outermost peripheral area of ​​the substrate 210, it is sometimes difficult to detect the EGA measurement mark formed on the substrate 210, but the substrate bonding device 100 can correctly detect the EGA measurement mark by executing this sequence.

[0195] In the above embodiments, the substrate bonding apparatus 100 may further include a calculation device, which calculates at least one of the following parameters: the amount of convexity that causes the substrate 210 to be deformed into a convex shape, the adsorption area of ​​the outer peripheral portion of the substrate 210 adsorbed in order to hold the substrate 210 by the substrate holder 220, and the timing of releasing the substrate 210 from being held by the substrate holder 220, based on information related to the deformation of the substrate 210 on the release side. It is preferable to find the relationship between each parameter and the nonlinear deformation in the substrate 210 in advance. In addition, in this case, each parameter calculated by the calculation device may also be automatically set to the substrate bonding apparatus 100. In addition, the calculation device may also be provided separately from the substrate bonding apparatus 100, for example, the user obtains each parameter calculated by the calculation device and manually inputs it to the substrate bonding apparatus 100. In addition, the amount of convexity that causes the substrate 210 to be deformed into a convex shape may also be, for example, the amount of protrusion of the protruding member 250, or may be a value corresponding to the gap between the substrates 210 and 230 bonded to each other. In addition, the adsorption area for adsorbing the peripheral portion of the substrate 210 may be, for example, the area of ​​the substrate holder 220 corresponding to each of the multiple adsorption areas distinguished by the multiple support portions of the substrate holder 220, or the area of ​​the substrate 210 held by the substrate holder 220 on the back side of the surface of the substrate 210 that is bonded to the substrate 230.

[0196] In the above embodiments, instead of using a plurality of support parts to divide the adsorption area, a plurality of vacuum holes may be provided along the traveling direction of the bonding wave. In this case, the intervals between the vacuum holes may be set to allow the deformation caused by the lifting.

[0197] In the above embodiments, the protruding member is driven by air pressure, but a spring-type protruding member that does not use air pressure may be used instead. In this case, the spring has a pressure that only deforms the substrate, and the pressure of the spring is greater than the pressure load when the pair of substrates are brought into contact. In the case of a spring-type, the protruding member may be gradually pressed in by increasing the pressure load based on the workbench after the pair of substrates are brought into contact, and at this time, the two substrate holders may also be made into a structure with a spring-type protruding member. In this way, the deformation of the pair of substrates that are bonded can be made into a mirror image relationship with each other, and nonlinear deformation can be suppressed.

[0198] In the above multiple embodiments, regardless of whether the protrusion amount of the protruding part is constant or gradually decreases, the protrusion amount of the protruding part or its maximum value can be set in such a way that when the substrate on the release side is deformed due to the protruding part, the amount of nonlinear deformation generated in the substrate is below a predetermined threshold.

[0199] In each of the above multiple embodiments, countermeasures for nonlinear deformation caused by crystal anisotropy, rate deformation caused by air resistance, and nonlinear deformation caused by local bending of the substrate are described separately. In order to eliminate the positional deviation caused by these various deformations in the stacked substrate formed by bonding the substrates, several countermeasures may be combined, and preferably all of the countermeasures may be adopted.

[0200] In the above multiple embodiments, the structure in which the observation unit optically observes the initial bonding area bonding is described. Alternatively or on the basis of this, the observation unit may determine that the initial bonding area is bonded by, for example, detecting that a predetermined time has passed after the substrates first contact each other. In this case, data representing the relationship between the elapsed time and the size of the initial bonding area is pre-stored, and the observation unit determines that the initial bonding area is bonded based on the data. In addition, the observation unit may also determine that the initial bonding area is bonded by observing the change in the distance between the bonded substrates or by observing the change in the distance between the substrate and the substrate holder. In this case, the observation unit may also be provided with, for example: a light source and a shooting unit arranged on the same side relative to the bonded substrates, and a background plate arranged on the opposite side, the light source irradiates the bonded substrate within the shooting field of view of the shooting unit, and the shooting unit shoots an image of the bonding state of the substrate formed on the background plate. In addition, the image obtained by the shooting unit is not limited to the image obtained by directly shooting the shape of the substrate, for example, the state of the bonding of the substrate may also be judged based on the change in the interference fringe image generated by optical phenomena such as interference generated between the bonded substrates.

[0201] In addition, the observation unit can also judge that the initial bonding area is bonded by observing the change of the electrical characteristics of at least one side of the bonded substrates. In this case, the observation unit, for example, has an electrostatic capacitance detection unit, which applies a periodically changing electrical signal to the LC resonance circuit formed by the electrostatic capacitance and standard inductance between a pair of substrates to be measured. At this time, the electrostatic capacitance detection unit superimposes an AC voltage on the DC voltage applied to the substrate holder having the function of an electrostatic chuck, and detects the AC component of the electrical signal that changes according to the change of the electrostatic capacitance in a pair of substrates. As the bonding wave advances, the interval between the bonded substrates becomes narrower, and the narrower the interval, the greater the electrostatic capacitance between the pair of substrates. Therefore, the observation unit can also detect the change of the electrostatic capacitance corresponding to the change of the bonding state of the substrate by making the electrical terminal contact with each bonded substrate, thereby judging the bonding state of the substrate. In the substrate holder on the release side, for example, the protruding member 250 can also be used as an electrical terminal. The control unit can also judge that the bonding is completed by detecting that the value of the electrostatic capacitance is constant and the constant load value is maintained for a threshold time.

[0202] In the above embodiment, the substrate 210 is carried into the upper stage 322 while being held in the substrate holder 220 or 920 on its entire surface, and a bonding wave is generated by releasing the holding of a part of the substrate holder 220 or 920 to form the initial bonding area 803. However, the following embodiment may be used instead. The substrate 210 is carried into the upper stage 322 while being held in the substrate holder 220 or 920 on its entire surface, and a part of the substrate 210 is brought into contact with the substrate 230 to form a contact area. Then, while the outer peripheral portion of the substrate 210 is held in the substrate holder 220 or 920, a bonding wave is autonomously generated between the substrates 210 and 230 by the intermolecular force between the activated surfaces, etc., to form the initial bonding area 803. In this case as well, when or after the determination unit determines that the initial bonding area 803 is formed during the period until the bonding wave stops, the holding of the outer peripheral portion of the substrate 210 by the substrate holder 220 or 920 is released. Alternatively, the size of the holding area of ​​the substrate 210 by the substrate holders 220 and 920 may be set so that the size of the initial bonding region 803 formed when the bonding wave of the substrate 210 stops is a predetermined size.

[0203] The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. According to the description of the claims, the method to which such changes or improvements are made is also included in the technical scope of the present invention.

[0204] It should be noted that the execution order of each process such as actions, sequences, steps and stages in the apparatus, system, program and method shown in the claims, specifications and drawings can be implemented in any order unless "before", "before", etc. are specifically indicated, and the output of the previous process is not used for the subsequent process. Regarding the action flow in the claims, specifications and drawings, "first," "next," etc. are used for convenience, which does not mean that it must be implemented in this order.

[0205] Explanation of reference numerals: 100 ... substrate bonding device; 110 ... housing; 120, 130 ... substrate box; 140 ... conveying unit; 150 ... control unit; 208, 209 ... silicon single crystal substrate; 210, 230, 610, 630 ... substrate; 212, 232 ... scribe line; 214 ... notch; 215 ... raised portion; 216, 236 ... circuit area; 218, 238 ... alignment mark; 220, 240, 920 ... substrate holder; 221, 241, 921 ... holding surface ; 223...recess; 224, 244, 924...support pin; 225, 226, 227, 247, 922, 925, 926, 927, 928...support portion; 229, 929...main body; 250...protruding member; 251...contact portion; 255...leaf spring; 290...laminated substrate; 300...bonding portion; 310...frame; 312...bottom plate; 316...top plate; 322...upper worktable; 324, 334...microscope; 326, 336...activation device 331…X-direction drive unit; 332…lower workbench; 333…Y-direction drive unit; 338…lifting drive unit; 341, 342, 343, 344…detector; 345…observation unit; 351…light source; 352…light receiving unit; 361, 362, 363, 364…observation window; 400…holder storage; 500…pre-aligner; 601, 602, 603, 604, 901, 902, 903, 904, 905…observation hole; 621…inner Peripheral ventilation path; 622, 933…outermost peripheral ventilation path; 625…central ventilation path; 640…ventilation path; 721, 723, 724, 725, 727, 751…control valve; 731…positive pressure source; 733, 734, 735, 737, 761…negative pressure source; 741, 743, 744, 745, 747, 771…open end; 801…fitting area; 803…initial fitting area; 931…inner peripheral ventilation path; 932…peripheral ventilation path.

Claims

1. A substrate bonding device, comprising: a first holding portion that holds a first substrate; a second holding portion that holds a second substrate; and a setting section for setting an initial bonding area, After a contact area is formed between a portion of the first substrate and a portion of the second substrate, the contact area is enlarged to form the initial bonding area, and the first substrate and the second substrate are bonded by releasing the second substrate having the initial bonding area formed thereon from the second holding portion, The setting unit sets the initial bonding area based on information related to deformation of the second substrate.

2. The substrate bonding device according to claim 1, wherein: The setting unit sets the initial bonding region so that a positional deviation amount between the first substrate and the second substrate after bonding is equal to or smaller than a threshold value.

3. The substrate bonding device according to claim 1, wherein: The setting unit sets the initial bonding area based on a location where warping occurs and a size of the warping in the bonding surface of the second substrate.

4. The substrate bonding device according to claim 2, wherein: The setting unit sets the initial bonding area based on a location where warping occurs and a size of the warping in the bonding surface of the second substrate.

5. The substrate bonding device according to any one of claims 1 to 4, wherein: The information related to the deformation includes at least one of a location where warping occurs in the second substrate, a magnitude of the warping, a direction of the warping, an amplitude of the warping, a magnitude of the bending, a direction of the bending, and an amplitude of the bending.

6. The substrate bonding device according to any one of claims 1 to 4, wherein: The information related to the deformation includes at least one of a maximum value and an average value of an amplitude of warpage of the outer peripheral portion of the second substrate.

7. The substrate bonding device according to any one of claims 1 to 4, wherein: The substrate bonding device further includes a measuring unit configured to measure a local bending property of the second substrate. The setting unit sets the initial bonding region based on the characteristic of the local curvature of the second substrate measured by the measuring unit.

8. The substrate bonding device according to any one of claims 1 to 4, wherein: The substrate bonding device further includes an inference unit configured to infer a characteristic of a local bending of the second substrate based on information related to a local bending of the second substrate included in the information related to the deformation of the second substrate. The setting unit sets the initial bonding region based on the characteristic of the local curvature of the second substrate estimated by the estimating unit.

9. The substrate bonding device according to claim 8, wherein: The information related to the local curvature includes at least one of information indicating the type of the second substrate, information indicating a manufacturing process, information indicating stress distribution, and information indicating a structure of a structure formed on the surface.

10. The substrate bonding device according to any one of claims 1 to 4, wherein: The substrate bonding device further comprises a determination unit configured to determine whether the initial bonding area is formed. When the determining unit determines that the initial bonding region is formed, the second holding unit releases the second substrate.

11. The substrate bonding device according to claim 10, wherein: The setting unit sets the initial bonding area and outputs the set information to the determination unit every time the first substrate and the second substrate are bonded together.

12. The substrate bonding device according to claim 10, wherein: The determination unit includes an observation unit that observes expansion of a contact area between the first substrate and the second substrate.

13. The substrate bonding device according to claim 11, wherein: The determination unit includes an observation unit that observes expansion of a contact area between the first substrate and the second substrate.

14. The substrate bonding device according to claim 11, wherein: The setting unit sets the initial bonding region for each manufacturing lot of the first substrate and each manufacturing lot of the second substrate, and outputs the set information to the determination unit.

15. The substrate bonding device according to claim 11, wherein: The setting unit sets the initial bonding region for each type of the first substrate and each type of the second substrate, and outputs the set information to the determination unit.

16. The substrate bonding device according to claim 11, wherein: The setting unit sets the initial bonding area for each manufacturing process of the first substrate and each manufacturing process of the second substrate, and outputs the set information to the determination unit.

17. The substrate bonding device according to claim 1, wherein: The second holding portion has: an adsorption portion that adsorbs at least an outer peripheral portion of the second substrate; as well as a protrusion that presses and deforms a central portion of the second substrate by protruding toward the second substrate, The protrusion amount of the protrusion is variable.

18. The substrate bonding device according to claim 2, wherein: The second holding portion has: an adsorption portion that adsorbs at least an outer peripheral portion of the second substrate; as well as a protrusion that presses and deforms a central portion of the second substrate by protruding toward the second substrate, The protrusion amount of the protrusion is variable.

19. The substrate bonding device according to claim 3, wherein: The second holding portion has: an adsorption portion that adsorbs at least an outer peripheral portion of the second substrate; as well as a protrusion that presses and deforms a central portion of the second substrate by protruding toward the second substrate, The protrusion amount of the protrusion is variable.

20. The substrate bonding device according to claim 4, wherein: The second holding portion has: an adsorption portion that adsorbs at least an outer peripheral portion of the second substrate; as well as a protrusion that presses and deforms a central portion of the second substrate by protruding toward the second substrate, The protrusion amount of the protrusion is variable.

21. The substrate bonding device according to claim 17, wherein: The protrusion is removable. The protrusion amount can be changed by replacing a plurality of protrusions having different heights.

22. The substrate bonding device according to any one of claims 18 to 20, wherein: The protrusion is removable. The protrusion amount can be varied by replacing a plurality of protrusions having different heights.

23. The substrate bonding device according to claim 17, wherein: The protrusion amount can be changed by the protrusion portion moving toward the second substrate.

24. The substrate bonding device according to any one of claims 18 to 20, wherein: The protrusion amount can be changed by the protrusion portion moving toward the second substrate.

25. The substrate bonding device according to claim 23, wherein: The substrate bonding device comprises: Control Department; and a displacement portion that displaces the relative position of the first holding portion and the second holding portion, The control unit controls at least one of the protruding unit and the displacement unit so that the protrusion amount decreases as the initial bonding area increases.

26. The substrate bonding device according to claim 24, wherein: The substrate bonding device comprises: Control Department; and a displacement portion that displaces the relative position of the first holding portion and the second holding portion, The control unit controls at least one of the protruding unit and the displacement unit so that the protrusion amount decreases as the initial bonding area increases.

27. The substrate bonding device according to claim 25, wherein: The control unit controls at least one of the protrusion and the displacement unit so that the initial bonding area is expanded while maintaining a constant deformation angle of an outer peripheral portion of the second substrate when the second substrate is deformed by the second holding unit.

28. The substrate bonding device according to claim 26, wherein: The control unit controls at least one of the protrusion and the displacement unit so that the initial bonding area is expanded while maintaining a constant deformation angle of an outer peripheral portion of the second substrate when the second substrate is deformed by the second holding unit.

29. The substrate bonding device according to any one of claims 17 to 21, 23, 25 to 28, wherein: The protrusion amount is set so that the amount of nonlinear deformation generated in the second substrate when the second substrate is deformed by the second holding portion is equal to or smaller than a predetermined threshold value.

30. The substrate bonding device according to any one of claims 17 to 21, 23, 25 to 28, wherein: The protrusion amount is set based on information related to deformation of the second substrate.

31. The substrate bonding device according to any one of claims 17 to 21, 23, 25 to 28, wherein: The adsorption part includes a plurality of adsorption areas which are isolated and independent from each other. As the initial bonding area expands, the suction of the plurality of suction areas is released sequentially from the center side toward the outer peripheral side of the second holding portion.

32. The substrate bonding device according to any one of claims 1 to 4, 9, 11 to 21, 23, 25 to 28, wherein: Before the initial bonding region is formed, the second holding portion does not hold the inner peripheral portion of the second substrate but holds the outer peripheral portion of the second substrate. When the initial bonding region is formed, the second holding portion releases the outer peripheral portion of the second substrate.

33. The substrate bonding device according to any one of claims 1 to 4, 9, 11 to 21, 23, 25 to 28, wherein: The second holding portion releases the second substrate in a state where the expansion of the contact area has progressed to more than half of the radius of the first substrate.

34. A substrate bonding device comprising: a first holding portion that holds a first substrate; a second holding portion that holds a second substrate; and a setting section for setting an initial bonding area, After forming a contact area between a portion of the first substrate and a portion of the second substrate, the contact area is expanded to form the initial bonding area while at least the outer periphery of the second substrate is held on the second holding portion, and then the first substrate and the second substrate are bonded by releasing the outer periphery of the second substrate from the second holding portion. The setting unit sets the initial bonding area based on information related to the deformation of the second substrate. The second holding portion holds the outer peripheral portion of the second substrate so as to suppress restoration of the curvature of the outer peripheral portion of the second substrate when the second substrate is released.

35. A substrate bonding device comprising: a first holding portion that holds a first substrate; a second holding portion that holds a second substrate; and a setting section for setting an initial bonding area, The first substrate and the second substrate are bonded together by releasing the second substrate from the second holding portion in the process of expanding the contact area formed between a portion of the first substrate and a portion of the second substrate to form the initial bonding area, The setting unit sets the initial bonding area based on information related to the deformation of the second substrate. The timing of releasing the second substrate from the second holding portion is different from the timing of releasing substrates other than the second substrate from the second holding portion.

36. A computing device for computing parameters used when a first substrate and a second substrate deformed into a convex shape are brought into contact with each other while being held separately and the first substrate and the second substrate are bonded together by releasing the holding of the second substrate, wherein: Based on information related to the deformation of the second substrate, at least one of the convex amount that causes the second substrate to deform into the convex shape, the adsorption area of ​​the outer peripheral portion of the second substrate that is adsorbed to hold the second substrate, the radial adsorption position of the second substrate, and the timing for releasing the hold of the second substrate is calculated.

37. A substrate bonding device, wherein: The substrate bonding device comprises the calculation device according to claim 36, The substrate bonding device bonds the first substrate and the second substrate together using the parameters calculated by the calculation device.

38. A substrate bonding method, comprising: A stage of holding a first substrate on a first holding portion; a stage of holding the second substrate on the second holding portion; a stage of setting an initial bonding area based on information related to the deformation of the second substrate; After a contact area is formed between a portion of the first substrate and a portion of the second substrate, the contact area is enlarged to form the initial bonding area; as well as A stage in which the first substrate and the second substrate are bonded together by releasing the second substrate on which the initial bonding area is formed from the second holding portion.

39. The substrate bonding method according to claim 38, wherein: The step of setting the initial bonding region includes the step of setting the initial bonding region so that the positional deviation amount between the first substrate and the second substrate after bonding is equal to or less than a threshold value.

40. The substrate bonding method according to claim 38, wherein: The step of setting the initial bonding region includes a step of setting the initial bonding region based on a location where warping occurs and a size of the warping in the bonding surface of the second substrate.

41. The substrate bonding method according to claim 39, wherein: The step of setting the initial bonding region includes a step of setting the initial bonding region based on a location where warping occurs and a size of the warping in the bonding surface of the second substrate.

42. The substrate bonding method according to any one of claims 38 to 41, wherein: The substrate bonding method further comprises: a stage of determining whether the initial bonding area has been formed; and When it is determined that the initial bonding region is formed, the second substrate on which the initial bonding region is formed is released from the second holding portion to bond the first substrate and the second substrate together.

43. A method for calculating parameters used when a first substrate and a second substrate deformed into a convex shape are brought into contact with each other while being held separately and the first substrate and the second substrate are bonded together by releasing the holding of the second substrate, wherein: The calculation method includes the following stages: based on information related to the deformation of the second substrate, calculating at least one parameter of the convex amount that causes the second substrate to be deformed into the convex shape, the adsorption area of ​​the outer peripheral portion of the second substrate that is adsorbed in order to hold the second substrate, the adsorption position in the radial direction of the second substrate, and the timing of releasing the hold of the second substrate.

44. A substrate bonding method comprising: A stage of calculating parameters using the calculation method of claim 43; and The first substrate and the second substrate are bonded together using the calculated parameters.

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