Joining device, joining method, and method for manufacturing article

Abstract

To provide a technique advantageous for obtaining a relative position between a pattern of a first member and a pattern of a second member after joining the first member and the second member to each other.SOLUTION: A joining device joins a second member having a second surface to be joined provided with a second pattern to a first member having a first surface to be joined provided with a first pattern, and comprises: a first imaging unit that picks up an image of the first surface to be joined; and a control unit that controls joining processing of aligning and joining the first member and the second member to each other. The control unit acquires, after the joining processing, feature position information indicating a position of a feature part of the second member with respect to the first member on the basis of an image obtained by picking up an image of the second member joined to the first member with the first imaging unit, and estimates a relative position between the first pattern and the second pattern after the joining processing on the basis of the feature position information and positional relationship information indicating a positional relationship between the feature part and the second pattern of the second member acquired in advance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a joining apparatus, a joining method, and a method for manufacturing an article. [Background technology]

[0002] Patent Document 1 describes a method for judging the quality of the bond between a chip and a substrate by measuring the amount of distortion of the chip and the substrate when ultrasonically bonding the chip to the substrate. Patent Document 2 describes a method for inspecting the quality of a bond between a substrate and a semiconductor chip by measuring the inclination of the semiconductor chip relative to the substrate based on an image obtained by imaging the bond between the substrate and the semiconductor chip from the side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-190527 [Patent Document 2] JP 2011-169816 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a bonding device for bonding a first member and a second member, it is important to reduce the deviation in the relative position between the pattern provided on the bonded surface of the first member and the pattern provided on the bonded surface of the second member after the first member and the second member are bonded. However, after the first member and the second member are bonded, the bonded surfaces of the first member and the second member cannot be confirmed from the outside. Therefore, it is difficult to easily and accurately obtain the relative position between the pattern of the first member and the pattern of the second member after bonding. In the methods described in Patent Documents 1 and 2, the quality of the bond between the first member (substrate) and the second member (chip) is judged only based on the appearance, and the relative position between the pattern of the first member and the pattern of the second member after bonding cannot be obtained.

[0005] Therefore, an object of the present invention is to provide an advantageous technique for obtaining the relative positions of a pattern of a first member and a pattern of a second member after the first member and the second member are joined. [Means for solving the problem]

[0006] In order to achieve the above object, a joining device as one aspect of the present invention is a joining device that joins a second member having a second joining surface on which a second pattern is provided to a first member having a first joining surface on which a first pattern is provided, and includes a first imaging unit that images the first joining surface of the first member, a second imaging unit that images the second joining surface of the second member, and a control unit that controls a joining process of aligning the first member and the second member and joining the second member to the first member based on a position of the first pattern in an image obtained by the first imaging unit and a position of the second pattern in an image obtained by the second imaging unit, wherein the control unit acquires, after the joining process, feature position information indicating a position of a characteristic portion of the second member relative to the first member based on an image obtained by imaging the second member joined to the first member by the first imaging unit, and estimates a relative position of the first pattern and the second pattern after the joining process based on positional relationship information indicating a positional relationship between the characteristic portion of the second member and the second pattern acquired in advance and the feature position information.

[0007] Further objects and other aspects of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. Effect of the Invention

[0008] According to the present invention, for example, it is possible to provide an advantageous technique for obtaining the relative position between a pattern of a first member and a pattern of a second member after the first member and the second member are joined. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram showing a bonding device according to a first embodiment; [Diagram 2] View of the stage from the +Z direction [Diagram 3] A schematic diagram showing how a die is imaged and an example of a die configuration [Figure 4] 1 is a flowchart showing an operation flow of the joining device in the first embodiment. [Diagram 5] FIG. 1 is a schematic diagram showing bonding of a wafer 6 and a die 51. [Figure 6] 1 is a flowchart showing an operation flow of a joining device in the first embodiment (modification). [Figure 7] FIG. 13 is a schematic diagram showing a joining device according to a second embodiment. [Figure 8] 11 is a flowchart showing an operation flow of the joining device in the third embodiment. [Figure 9] 11 is a flowchart showing the operation flow of the joining device in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0011] In this specification and the accompanying drawings, directions are typically shown in an XYZ coordinate system in which a plane parallel to a horizontal plane is the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X direction, the Y direction, and the Z direction, respectively, and the rotation around the X-axis, the Y axis, and the Z axis are θX, θY, and θZ, respectively. Control and drive (movement) regarding the X-axis, Y-axis, and Z-axis respectively mean control or drive (movement) regarding the direction parallel to the X-axis, the direction parallel to the Y axis, and the direction parallel to the Z axis. In addition, control or drive regarding the θX-axis, θY-axis, and θZ-axis respectively mean control or drive regarding the rotation around an axis parallel to the X-axis, the rotation around an axis parallel to the Y axis, and the rotation around an axis parallel to the Z axis.

[0012] In the embodiments described below, an example will be described in which a wafer (substrate) on which a semiconductor device is formed is used as a first member (first bonded object), and a die (chip) obtained by dividing the wafer on which the semiconductor device is formed is used as a second member (second bonded object). However, the first member and the second member are not limited to these bonded objects, and various modifications and changes are possible within the scope of the gist of the invention.

[0013] The first member may be a substrate having a bonding surface (first bonding surface) on which a pattern (first pattern) is provided. Examples of the substrate include a wafer on which a semiconductor device is formed, a silicon wafer, a silicon wafer on which wiring is formed, a glass wafer, a glass panel on which wiring is formed, an organic panel (PCB) on which wiring is formed, and a metal panel. The substrate may be a wafer on which one or more dies are already bonded.

[0014] The second member may be a chip having a bonding surface (second bonding surface) on which a pattern (second pattern) is provided. Examples of the chip include dies obtained by dividing a wafer on which semiconductor devices are formed, stacks of several dies, small pieces of material, optical elements, MEMS, and structures.

[0015] In the embodiments described below, various temporary or permanent bonding methods can be used to bond the first and second members, such as bonding with an adhesive, temporary bonding with a temporary adhesive, hybrid bonding, atomic diffusion bonding, vacuum bonding, bump bonding, and the like.

[0016] Next, examples of industrial applications of the embodiments described below will be described. A first application example is the manufacture of a stacked memory. When a bonding apparatus according to an embodiment described later is applied to the manufacture of a stacked memory, a wafer (substrate) on which a memory, which is a semiconductor device, is formed is used as a first member, and a die (chip) on which the memory is formed is used as a second member. For example, in the manufacture of a stacked memory having eight memory layers, a second member (die) formed as the eighth memory layer is bonded onto a first member (substrate) that already has seven memory layers. Note that the final layer of the stacked memory need not be a memory layer, but may be a layer on which a driver for driving the memory is formed.

[0017] A second application example is heterogeneous integration of a processor. Conventional processors are mainly SoCs (System on Chip) in which logic circuits and SRAMs (Random Access Memory) are configured in one semiconductor element. In contrast, heterogeneous integration is a method of manufacturing a processor by creating multiple types of elements on separate wafers by applying the optimal process for each element and bonding them together. This can reduce the cost of the processor and improve the yield. When the bonding apparatus of the embodiment described later is applied to heterogeneous integration, a wafer (substrate) on which a logic device, which is a semiconductor device, is formed is used as the first member. Then, dies (chips) such as SRAMs, antennas, and drivers that are singulated after probing are used as the second member. In heterogeneous integration, for example, different types of dies are bonded together in sequence, so that the number of objects bonded to the first member increases in sequence. Specifically, when a die having an SRAM is bonded onto a logic wafer, the logic wafer is the first member, and the die having an SRAM is the second member. In addition, when a die having an element to be formed on the SRAM is bonded on a die having the SRAM, the bonded product of the logic wafer and the die having the SRAM becomes the first member, and the die having the element becomes the second member. When multiple dies are stacked and bonded, it is desirable to bond them in the order of thinnest dies first so that the bonding head does not interfere with the dies already bonded.

[0018] A third application example is 2.5D bonding using a silicon interposer. A silicon interposer is a silicon wafer on which wiring is formed. In 2.5D bonding, multiple types of dies are bonded onto a silicon interposer, and the multiple types of dies are electrically connected to each other by the wiring on the interposer. When a bonding device according to an embodiment described later is applied to 2.5D bonding, a silicon wafer on which wiring is formed is used as a first member, and individualized dies are used as a second member. In 2.5D bonding, for example, since multiple types of dies are bonded to a silicon interposer, a silicon interposer structure to which one or more dies have already been bonded may be treated as the first member. Note that when multiple types of dies are bonded to a silicon interposer, it is desirable to bond the dies from the thinnest dies so that the bonding head does not interfere with the dies already bonded.

[0019] A fourth application example is 2.1D bonding using an organic interposer or a glass interposer. An organic interposer is an organic panel (PCB substrate, CCL substrate) used as a package substrate on which wiring is formed. A glass interposer is a glass panel on which wiring is formed. 2.1D bonding is a bonding of multiple types of dies onto an organic interposer or a glass interposer, and electrical connection between the multiple types of dies is performed by wiring on the interposer. When a bonding device of an embodiment described later is applied to 2.1D bonding, in 2.1D bonding using an organic interposer, an organic panel on which wiring is formed is used as a first member, and a singulated die is used as a second member. On the other hand, in 2.1D bonding using a glass interposer, a glass panel on which wiring is formed is used as a first member, and a singulated die is used as a second member. In 2.1D bonding, for example, multiple types of dies are bonded to an organic interposer or glass interposer, so the organic interposer or glass interposer structure to which one or more dies have already been bonded may be treated as the first component. When multiple types of dies are bonded to an interposer, it is desirable to bond them in the order of thin dies first, so that the bonding head does not interfere with the dies that have already been bonded.

[0020] A fifth application example is a temporary bonding in a fan-out package manufacturing process. For example, fan-out packages as advanced packages applied to semiconductor manufacturing processes include fan-out wafer level packages and fan-out panel level packages. A fan-out wafer level package is a package in which individualized dies are reconstructed into a wafer shape using mold resin. A fan-out panel level package is a package in which individualized dies are reconstructed into a panel shape using mold resin. In such a fan-out package, when packaging, rewiring from the die to the bumps or rewiring for bonding different types of dies together is formed on a molded reconstructed substrate. At this time, if the arrangement accuracy of the dies is low, it may be difficult to align the rewiring pattern with high accuracy when transferring the rewiring pattern using a step-and-repeat exposure device. Therefore, in a fan-out package, it is required to arrange multiple dies with high accuracy. When a bonding device of an embodiment described later is applied to a fan-out package manufacturing process, a metal panel is used as a first member, and an individualized die is used as a second member. Specifically, a bonding device is used to temporarily bond the individual dies to a metal panel in sequence using a temporary bonding agent. The dies temporarily bonded on the metal panel are then molded into a wafer shape or a panel shape by a molding device, and the molded dies are peeled off from the metal panel. This produces a reconstituted wafer or a reconstituted panel in which the dies are arranged. Note that in the fan-out package manufacturing process, the arrangement of the dies may change in the molding process. Therefore, when the dies are temporarily bonded on the metal panel using the bonding device, it is desirable to adjust the bonding position of each die on the metal panel so that the change in the arrangement that occurs in the molding process is corrected.

[0021] A sixth application example is heterogeneous substrate bonding. For example, in an infrared image sensor, InGaAs, which is known as a highly sensitive material, is used for the sensor part that receives light, and silicon, which is capable of high-speed processing, is used for the logic circuit that extracts data. This makes it possible to manufacture a highly sensitive and high-speed infrared image sensor. However, InGaAs crystals are mass-produced only in small diameters such as 4 inches, which are smaller than the 300 mm that is the mainstream for silicon wafers. For this reason, a method has been proposed in which a die obtained by dividing an InGaAs substrate is bonded onto a 300 mm silicon wafer on which a logic circuit is formed. In this way, the bonding device of the embodiment described below can be applied to heterogeneous substrate bonding in which substrates made of different materials and having different sizes are bonded together. When the bonding device is applied to heterogeneous substrate bonding, a large-diameter substrate such as a silicon wafer is used as the first member, and a die (small piece) of a material such as InGaAs is used as the second member. The die (small piece) of a material such as InGaAs may be a sliced ​​crystal, but it is preferable to cut it into a square shape.

[0022] First Embodiment A first embodiment of the present invention will be described. Fig. 1 is a schematic diagram showing a bonding apparatus 100 of the first embodiment. In Fig. 1, a direction perpendicular to a holding surface of a stage 43 (described later) that holds a wafer 6 (substrate) is defined as a Z direction, and directions perpendicular to each other in a plane parallel to the holding surface of the stage 43 are defined as an X direction and a Y direction. The bonding apparatus 100 is an apparatus that sequentially bonds each of a plurality of dies 51, which are second objects to be bonded, to a predetermined position on a wafer 6, which is a first member (first object to be bonded). The plurality of dies 51 are arranged on a dicing tape attached to a dicing frame 5.

[0023] In this embodiment, the bonding device 100 includes a pickup unit 3, a bonding unit 4, and a control unit CNT, as shown in Fig. 1. The pickup unit 3 and the bonding unit 4 are mounted on a base 1 that is vibration-damped by a mount 2. In this embodiment, the pickup unit 3 and the bonding unit 4 are mounted on the same base 1, but they may be mounted individually on different bases.

[0024] The pickup unit 3 includes a pickup head 31, a release head 32, and a frame holding unit 33, and picks up the dies 51 one by one from the dicing tape attached to the dicing frame 5. The frame holding unit 33 holds the dicing frame 5. The release head 32 pushes up the target die 51 from the back side of the dicing tape attached to the dicing frame 5 so that the die 51 to be picked up protrudes above the other dies. At this time, the target die 51 is partially peeled off from the dicing tape. The pickup head 31 holds (adsorbs) the target die 51 pushed up by the release head 32 by vacuum force or the like, and peels (separates) the target die 51 from the dicing tape. The pickup head 31 is configured to be movable from the pickup unit 3 to the bonding unit 4. The pickup head 31 rotates (flip-chips) the die 51 so that the top and bottom are inverted while moving from the pickup unit 3 to the bonding unit 4, and delivers the die 51 to a bonding head 44 described later. Here, the pickup head 31 comes into contact with the joining surface (second joining surface) of the die 51. Therefore, when making it compatible with a joining method that activates the surface for joining, such as hybrid bonding, it is advisable to apply a highly stable surface treatment, such as a diamond-like carbon (DLC) coat or a fluorine coat, to the joining surface of the die 51.

[0025] The bonding section 4 includes a stage 43, a bonding head 44, a die observation camera 45, a wafer observation camera 46, and an interferometer 47. The stage 43 is configured to be movable on a stage base 41, and the die observation camera 45 is mounted on the stage 43. In addition, the bonding head 44, the wafer observation camera 46, and the interferometer 47 are mounted on an upper base 42.

[0026] First, a description will be given of the configuration on the stage base 41. On the stage base 41, a stage 43 and a die observation camera 45 are provided.

[0027] The stage 43 (first holding unit) includes a chuck 431 that holds the wafer 6 (substrate) on a holding surface parallel to the XY directions by vacuum force or the like, and a driving mechanism 432 that drives the chuck 431 (wafer 6). The driving mechanism 432 includes an actuator such as a linear motor, and is configured to be able to drive the wafer 6 in the XY directions and the θZ directions. The driving mechanism 432 may be configured to be able to drive the wafer 6 in the Z direction. The relative rotational movement of the wafer 6 and the die 51 in the θZ direction may be performed by rotating the wafer 6 by the stage 43, but in addition to or instead of that, it may be performed by rotating the die 51 by a bonding head 44 described later. In addition, the stage 43 is provided with a mirror 433 for measuring the position of the stage 43 in the XY directions. The mirror 433 is a target of an interferometer 47 described later that measures the position of the stage 43 in the XY directions.

[0028] The die observation camera 45 (second imaging unit) is a camera for observing the bonded surface (second bonded surface) of the die 51, and can be disposed so as to be able to image the bonded surface of the die 51 while the die 51 is held by the bonding head 44 (second holding unit). In this embodiment, the die observation camera 45 is mounted on the stage 43, and is movable in the XY directions in accordance with the movement of the stage 43. The die observation camera 45 is used to acquire (measure) information indicating the position of a pattern (second pattern) provided on the bonded surface of the die 51, and information indicating the positional relationship between a characteristic portion of the die 51 and the pattern provided on the bonded surface of the die 51.

[0029] The characteristic part of the die 51 is, for example, an index that can be confirmed in both an image obtained by imaging the surface to be joined of the die 51 and an image obtained by imaging the back surface (the surface opposite to the surface to be joined) of the die 51. In other words, the characteristic part of the die 51 is an index that can be used as a positional reference on both the surface to be joined and the back surface of the die 51. Specifically, examples of the characteristic part of the die 51 include the outer edge of the die 51 and / or a through via (through hole) that penetrates from the surface to be joined of the die 51 to the back surface.

[0030] The die observation camera 45 is also used to measure the distance in the height direction (Z direction) between multiple points on the bonded surface of the die 51, i.e., the height distribution of the bonded surface of the die 51. That is, the die observation camera 45 can be used to measure the position in the height direction, the inclination, and / or the flatness of the bonded surface of the die 51 held by the bonding head 44. Note that in this embodiment, the pattern provided on the bonded surface of the die 51 can be defined to include marks for measuring the position of the die 51 in addition to the circuit pattern.

[0031] Next, a description will be given of the mechanisms mounted on the upper base 42. A bonding head 44, a wafer observation camera 46, and an interferometer 47 are mounted on the upper base 42.

[0032] The bonding head 44 (second holding unit) holds the die 51 delivered from the pickup head 31 by vacuum force or the like, and drives the die 51 in the -Z direction to bond the die 51 to the wafer 6. In this embodiment, the bonding of the die 51 to the wafer 6 is performed by driving the die 51 in the -Z direction by the bonding head 44, but this is not limited thereto. For example, the bonding of the die 51 to the wafer 6 may be performed by driving the wafer 6 in the +Z direction by the stage 43, or may be performed by driving the die 51 and the wafer 6 relatively by the bonding head 44 and the stage 43.

[0033] The wafer observation camera 46 (first imaging unit) is a camera for observing the bonded surface (first bonded surface) of the wafer 6, and can be arranged so as to be able to image the wafer 6 while the wafer 6 is held by the stage 43 (first holding unit). The wafer observation camera 46 is used to acquire (measure) information indicating the position of a pattern (first pattern) provided on the bonded surface of the wafer 6, and information indicating the position of a characteristic part of the die 51 with respect to the wafer 6 after the wafer 6 and the die 51 are bonded. The wafer observation camera 46 is also used to measure the distance in the height direction (Z direction) of a plurality of points on the bonded surface of the wafer 6, that is, the height distribution of the bonded surface of the wafer 6. That is, the wafer observation camera 46 can be used to measure the position in the height direction, the inclination, and / or the flatness of the bonded surface of the wafer 6 held by the stage 43. Further, the interferometer 47 irradiates light onto a mirror 433 provided on the stage 43 , and measures the position of the stage 43 based on the light reflected from the mirror 433 .

[0034] Here, the bonding apparatus 100 of the present embodiment is configured such that the pick-up head 31 rotates (flip-chips) to deliver the die 51 to the bonding head 44, but is not limited thereto. For example, two or more die holders may be provided between the pick-up head 31 and the bonding head 44, and the die 51 may be delivered to the bonding head 44 after flip-chip by delivering the die 51 to the two or more die holders. Also, a drive mechanism for driving the bonding head 44 may be provided between the pick-up unit 3 and the bonding unit 4, and the bonding head 44 itself may go to the bonding unit 4 to receive the die 51. Also, in order to improve productivity, the bonding apparatus 100 may be provided with a plurality of pick-up units 3, a plurality of pick-up heads 31, a plurality of release heads 32, and a plurality of bonding heads 44.

[0035] The control unit CNT is composed of a computer (information processing device) having a processor such as a CPU (Central Processing Unit) and a storage unit such as a memory, and controls each unit of the bonding device 100 to control the bonding process. The bonding process is a process of aligning the wafer 6 and the die 51 so that the pattern (first pattern) of the wafer 6 and the pattern (second pattern) of the die 51 overlap with each other, and bonding the die 51 to the wafer 6. Specifically, the control unit CNT determines the position of the pattern (first pattern) provided on the bonded surface of the wafer 6 based on an image of the bonded surface (first bonded surface) of the wafer 6 captured by the wafer observation camera 46. In addition, the control unit CNT determines the position of the pattern (second pattern) provided on the bonded surface of the die 51 based on an image of the bonded surface (second bonded surface) of the die 51 captured by the die observation camera 45. Thereby, the control unit CNT can control the bonding process based on the position of the pattern of the wafer 6 and the position of the pattern of the die 51.

[0036] FIG. 2 is a view of the stage 43 as seen from the +Z direction. The wafer 6 is held by a chuck 431. To perform two-dimensional positioning, the stage 43 is provided with a bar mirror 433x for measuring the position in the X direction and the θZ direction (rotation direction) and a bar mirror 433y for measuring the position in the Y direction. The bar mirror 433x is a target of the interferometer 47a and the interferometer 47c for measuring the position in the X direction. The interferometer 47a and the interferometer 47c are arranged apart from each other in the Y direction, and the amount of rotation (θZ direction) of the stage 43 can be obtained from the difference between the measurement result of the interferometer 47a and the measurement result of the interferometer 47c. The bar mirror 433y is a target of the interferometer 47b for measuring the position in the Y direction. The interferometers 47a to 47c measure the position of the stage 43 in the X direction, the position in the Y direction, and the amount of rotation in the θZ direction in real time. Thereby, the control unit CNT can feedback-control the driving of the stage 43 in real time and perform two-dimensional highly accurate positioning of the stage 43. In the bonding device 100 of this embodiment, the highly accurate position measurement by the interferometers 47a to 47c and the feedback control of the driving mechanism of the stage 43 based on the result of the measurement can function as a positioning mechanism for the stage 43.

[0037] Further, the stage 43 is mounted with a reference plate 434 having a plurality of marks 434a to 434c. The reference plate 434 is made of a material with a low thermal expansion coefficient, and has marks 434a to 434c formed (drawn) with high positional accuracy. For example, the reference plate 434 may be a quartz substrate on which marks are drawn using a drawing method for a semiconductor lithography process. The reference plate 434 may be configured so that its upper surface is at approximately the same height as the upper surface of the wafer 6 held on the stage 43 (chuck 431). In this embodiment, the reference plate 434 may be observed by the wafer observation camera 46, but this is not limited to the case where a camera for observing the reference plate is separately configured. Here, the stage 43 may be configured by a coarse movement stage capable of driving in a large range, and a fine movement stage capable of driving in a small range with high accuracy on the coarse movement stage. In this case, the die observation camera 45, the mirror 433, the chuck 431, and the reference plate 434 need to be positioned with high accuracy, so they are preferably fixed to a fine movement stage.

[0038] A method of guaranteeing the origin position, magnification, rotation in the θZ direction, and orthogonality of the stage 43 using the reference plate 434 will be described. The control unit CNT acquires the measurement values ​​of the interferometers 47a to 47c when the mark 434a is placed at the center of the image acquired by the wafer observation camera 46 while having the wafer observation camera 46 image (observe) the mark 434a, and sets the measurement values ​​as the origin of the stage 43. Next, the control unit CNT acquires the measurement values ​​of the interferometers 47a to 47c when the mark 434b is placed at the center of the image acquired by the wafer observation camera 46 while having the wafer observation camera 46 image (observe). Then, the control unit CNT determines the Y-axis direction and Y magnification of the stage 43 from the acquired measurement values. Next, the control unit CNT acquires the measurement values ​​of the interferometers 47a to 47c when the mark 434c is placed at the center of the image acquired by the wafer observation camera 46 while making the wafer observation camera 46 capture (observe) the mark 434c. Then, from the acquired measurement values, the direction of the X axis and the X magnification of the stage 43 are determined. That is, the direction from the mark 434b to the mark 434c on the reference plate 434 is set as the Y axis of the bonding apparatus 100, and the direction from the mark 434a to the mark 434c is set as the X axis of the bonding apparatus 100, and the calibration of the axis direction and the orthogonality is performed. Then, the calibration is performed with the interval between the mark 434b and the mark 434c as the scale reference in the Y direction of the bonding apparatus 100, and the interval between the mark 434a and the mark 434c as the scale reference in the X direction of the bonding apparatus 100. Since the refractive index of the interferometer optical path changes due to fluctuations in air pressure and temperature, causing fluctuations in the measurement values ​​of the interferometers 47a to 47c, it is desirable to perform calibration at any timing to ensure the origin position, magnification, rotation, and orthogonality of the stage 43. Note that, in order to reduce fluctuations in the measurement values ​​of the interferometers 47a to 47c, the space in which the stage 43 moves may be enclosed in a temperature-controlled chamber to control the temperature.

[0039] In the present embodiment, an example has been described in which the reference plate 434 is attached to the stage 43 and the reference plate 434 is imaged (observed) by the wafer observation camera 46, but the present invention is not limited thereto. For example, the reference plate 434 may be attached to the upper base 42 and the reference plate 434 may be imaged (observed) by the die observation camera 45. Even in this configuration, the origin position, magnification, rotation, and orthogonality of the stage 43 can be guaranteed. In addition, in the present embodiment, an example has been described in which the reference plate 434 is imaged (observed) and calibration is performed, but the present invention is not limited thereto. For example, calibration may be performed by abutting against a reference surface. Furthermore, the stage 43 may be positioned with high accuracy by using a position measuring means whose absolute value is guaranteed, such as a white light interferometer.

[0040] In the bonding apparatus 100 configured as described above, it is important to reduce the deviation of the relative position between the pattern provided on the bonded surface of the wafer 6 (first member) and the pattern provided on the bonded surface of the die 51 after the die 51 is bonded to the wafer 6. However, after the die 51 is bonded to the wafer 6, the bonded surfaces of the wafer 6 and the die 51 cannot be confirmed from the outside. Therefore, it has been difficult to easily and accurately obtain the relative position between the pattern of the wafer 6 and the pattern of the die 51 after bonding. Here, there is a method of using an infrared camera as the wafer observation camera 46. In this method, infrared light is used to transmit through the die 51 and capture an image, and the relative position between the pattern of the wafer 6 and the pattern of the die 51 after bonding is measured. However, such an infrared camera is expensive, and may be disadvantageous in terms of the equipment cost of the bonding apparatus 100. Furthermore, even when an infrared camera was used, it was not possible to clearly capture the pattern of the wafer 6 and the pattern of the die 51 after bonding, making it difficult to accurately measure the relative positions of the pattern of the wafer 6 and the pattern of the die 51 after bonding.

[0041] Therefore, in the bonding apparatus 100 of this embodiment, after the bonding process between the wafer 6 (first member) and the die 51 (second member), the control unit CNT causes the wafer observation camera 46 (first imaging unit) to capture an image of the appearance of the die 51 bonded to the wafer 6. Then, based on the image obtained by the wafer observation camera 46, the control unit CNT acquires feature position information indicating the position of the feature of the die 51 relative to the wafer 6. Next, based on the positional relationship information indicating the positional relationship between the feature of the die 51 and the pattern of the die 51 acquired in advance and the feature position information, the control unit CNT estimates the relative position between the pattern of the wafer 6 and the pattern of the die 51 after the bonding process. This makes it possible to easily and accurately obtain the pattern of the wafer 6 and the pattern of the die 51 after the bonding process. Hereinafter, an example of this embodiment will be described.

[0042] [Example 1] The operation of the bonding apparatus 100 in the first embodiment will be described with reference to FIGS. 3 and 4. FIG. 3(a) is a schematic diagram showing an image of the die 51, and FIG. 3(b) is a schematic diagram showing a configuration example of the die 51 used in the first embodiment. As shown in FIG. 3(b), the die 51 used in the first embodiment has a bonded surface 51a and a back surface 51b, which is the surface opposite to the bonded surface. The bonded surface 51a is provided with an element pattern 501 (second pattern) and an alignment mark 502. The die 51 is provided with a through via 503 that penetrates from the bonded surface 51a to the back surface 51b. In FIG. 3(b), the through via 503 is illustrated only on the back surface 51b, but it may be understood that at least a part of the through via 503 is exposed also on the bonded surface 51a. In this case, the through via 503 can be used as the above-mentioned characteristic part. FIG. 4 is a flowchart showing the operation flow of the bonding apparatus 100 in the first embodiment. Each step in the flowchart of FIG. 4 can be executed by the control unit CNT.

[0043] In step S101, the control unit CNT uses a wafer transport mechanism (not shown) to load the wafer 6, which is a first member (first bonded object), onto the stage 43 (chuck 431) of the bonding apparatus 100. At this time, if a foreign object adheres to the bonded surface of the wafer 6, bonding failure occurs, so it is desirable that the inside of the bonding apparatus 100 is a space with a high cleanliness level of about class 1. In order to maintain the high cleanliness of the wafer 6 as well, it is desirable to store the wafer 6 in a container that is highly airtight and maintains a high level of cleanliness, and transport the wafer 6 from the container onto the stage 43 of the bonding apparatus 100. An example of the container is a FOUP (Front Opening Unify Pod).

[0044] Here, in order to improve the cleanliness of the wafer 6, a cleaning mechanism for cleaning the wafer 6 may be provided inside the bonding apparatus 100. Also, a mechanism for performing pre-processing of the wafer 6 for the bonding process may be provided inside the bonding apparatus 100. Examples of pre-processing include a process of applying an adhesive to the surface to be bonded of the wafer 6 in the case of bonding with an adhesive, and a process of activating the surface to be bonded of the wafer 6 in the case of hybrid bonding. The positions of the wafer 6 in the θZ direction and the XY direction are measured by a pre-alignment unit (not shown), and the wafer 6 is roughly positioned based on the measurement results, and then transferred onto the chuck 431 of the stage 43. The position of the wafer 6 in the θZ direction is measured by detecting the notch or orientation flat of the wafer 6, and the position of the wafer 6 in the XY direction can be measured by detecting the outer shape of the wafer 6.

[0045] In step S102, the control unit CNT performs wafer alignment using the wafer observation camera 46. In the wafer alignment, the wafer observation camera 46 captures an image of a bonding surface of a target area (bonding target) of the wafer 6 to which the die 51 is to be bonded, and based on the image thus obtained, the position of a pattern (first pattern) provided on the wafer 6 (target area) is obtained. Note that the wafer 6 has a plurality of target areas.

[0046] The focus adjustment when imaging the bonded surface of the wafer 6 may be performed by a focus adjustment mechanism provided in the wafer observation camera 46, or may be performed by driving the wafer 6 in the Z direction by the Z drive mechanism of the stage 43. If an alignment mark is provided on the bonded surface of the wafer 6, the position of the pattern on the wafer 6 can be obtained using the alignment mark. On the other hand, if no alignment mark is provided on the bonded surface of the wafer 6, the position of the pattern on the wafer 6 may be obtained using a portion of the test surface where the position of the pattern can be identified (hereinafter, sometimes referred to as an identifiable portion). For example, a part of the pattern on the wafer 6 can be used as the identifiable portion.

[0047] For example, the control unit CNT can measure the position of the pattern of the wafer 6 by measuring the image position of the projected alignment mark or identifiable location with respect to the center of the image acquired by the wafer observation camera 46. In the following, the alignment mark or identifiable location may be referred to as the alignment mark or the like. As an example, there is a method for measuring the position of the alignment mark or the like with respect to the reference point of the bonding device 100 with high accuracy. In this method, the stage 43 is driven in advance so that the mark formed on the reference plate 434 falls within the imaging field of the wafer observation camera 46, and the mark on the reference plate 434 is imaged by the wafer observation camera 46. Based on the position of the stage 43 at that time and the mark position in the image obtained by the wafer observation camera 46, the reference point of the bonding device 100 is determined. Then, based on the image obtained by imaging the alignment mark or the like by the wafer observation camera 46, the offset amount of the position of the alignment mark or the like with respect to the reference point is obtained. As a result, the position of the alignment mark can be measured with high accuracy from the position of the reference point and the offset amount. In the first embodiment, the position of the mark on the reference plate 434 is used as the position of the reference point of the bonding apparatus 100, but another position may be used as long as it serves as a reference position.

[0048] Here, since the interferometer 47 has a narrow measurement range in the θZ direction, the amount of rotation in the θZ direction that can be corrected by the stage 43 is relatively small. Therefore, when the amount of rotation in the θZ direction of the wafer 6 is large, it is desirable to rearrange the wafer 6 on the stage 43 so that the amount of rotation in the θZ direction of the wafer 6 is corrected. When the wafer 6 is rearranged on the stage 43, it is necessary to measure the position of the wafer 6 again. Also, during the execution of step S102, it is preferable to measure the surface position of the wafer 6 using a first height measuring means (not shown) that measures the surface position of the surface to be bonded of the wafer 6. This is because the thickness of the wafer 6 varies, and the surface position of the wafer 6 is important for managing (controlling) the gap between the wafer 6 and the die 51 with high accuracy during the bonding process.

[0049] Since the stage 43 uses a reference plate to guarantee the origin position, magnification, position in the XY direction, rotation in the θZ direction, and orthogonality, the position of the wafer 6 mounted on the stage 43 relative to the origin position of the stage 43, etc., can be measured. The wafer 6 has target areas (bonding targets, target areas) in which semiconductor devices are formed, which are repeatedly arranged at a constant period within the wafer 6. That is, the wafer 6 includes a plurality of target areas to which the dies 51 are respectively bonded. Since the semiconductor devices in each target area are positioned and manufactured with high accuracy using a semiconductor manufacturing device, the plurality of target areas in the wafer 6 are generally arranged with high accuracy at a repeating period of nano-level accuracy. Therefore, in the wafer alignment in step S102, it is not necessary to measure the positions of all the target areas in the wafer 6, and it is sufficient to measure the positions of some of the bonding targets among the plurality of target areas in the wafer 6. Specifically, the positions of the semiconductor devices (patterns, marks) in three or more target areas among the plurality of target areas in the wafer 6 are measured and statistically processed. This makes it possible to calculate the array of the target area, the origin position of the array, the position in the XY directions, the amount of rotation and orthogonality in the θZ direction, and the magnification error of the repetition period.

[0050] The chuck 431 may also include a mechanism for adjusting the temperature of the wafer 6. For example, the thermal expansion coefficient of a silicon wafer is 3 ppm / °C, and in the case of a wafer with a diameter of 300 mm, a 1°C rise in temperature will cause the position to move by 150 mm x 0.000003 = 0.00045 mm = 450 nm at the outermost periphery. If the bonding position (e.g., the position of the target area) moves after wafer alignment, it may be difficult to bond the wafer 6 and the die 51 with high accuracy. For this reason, it is preferable to adjust the temperature of the wafer 6 so that the temperature change of the wafer 6 is 0.1 degrees or less.

[0051] In Example 1, the wafer 6 was used as the first member (first bonded object), but when an interposer on which wiring is formed is used as the first member, the arrangement of the repeatedly formed wiring is measured, not the arrangement of the semiconductor devices. Also, when a wafer or panel on which no pattern is formed is used as the first member, the wafer alignment in step S102 does not need to be performed.

[0052] The above steps S101 and S102 are steps related to the first member (first object to be bonded) which is the wafer 6. Meanwhile, in parallel with steps S101 and S102, steps (steps S201 to S203) related to the die 51 which is the second member (second object to be bonded) are carried out.

[0053] In step S201, the control unit CNT uses a conveying mechanism (not shown) to carry the dicing frame 5 into the pickup unit 3 (on the frame holding unit 33). The dicing frame 5 is a frame with an opening in the center, and a dicing tape is attached to the dicing frame 5 so as to cover the opening. A plurality of dies 51, which have been cut into individual pieces by a cutting device such as a dicer, are arranged on the dicing tape. Conventionally, the dicing frame 5 has been transported in an unsealed magazine. However, if foreign matter adheres to the bonded surface 51a of the die 51, bonding failure occurs, so it is necessary to transport the die 51 in a container that is highly sealed and kept clean. Here, in order to increase the cleanliness of the die 51, a cleaning mechanism for cleaning the die 51 on the dicing frame 5 (dicing tape) may be provided inside the bonding device 100. Furthermore, the dicing frame 5 can be transported onto the frame holding part 33 after the rotation in the θZ direction and the shift position (position in the XY directions) are roughly positioned based on the outer shape of the dicing frame 5 by a pre-alignment unit (not shown).

[0054] In step S202, the control unit CNT controls the pickup head 31 and the release head 32 to pick up one die 51 from the dicing frame 5 (dicing tape). Specifically, the control unit CNT first moves the pickup head 31 and the release head 32 to the position of the target die 51 to be picked up (hereinafter, may be referred to as the target die 51). Then, the control unit CNT drives the release head 32 in the +Z direction to push up the target die 51 from the back side of the dicing tape, and in that state, drives the pickup head 31 in the -Z direction so that the pickup head 31 and the target die 51 come into contact with each other. As a result, the target die 51 is held (adsorbed) by the pickup head 31 with a vacuum force or the like, and the target die 51 can be peeled off from the dicing tape by driving the pickup head 31 in the +Z direction. The target die 51 to be picked up can be determined based on known good die (KGD) information transmitted online to the bonding device 100. Usually, only good dies are picked up as the target dies 51 , but for target areas of the wafer 6 that have defective devices, known bad dies (KBDs) may be picked up as the target dies 51 .

[0055] In step S203, the control unit CNT transfers (transfers) the target die 51 picked up by the pick-up head 31 to the bonding head 44 of the bonding unit 4. Specifically, as shown in FIG. 1, the control unit CNT drives the pick-up head 31 that picked up the target die 51 in the X direction to place the pick-up head 31 below the bonding head 44. Then, the control unit CNT drives the pick-up head 31 in the +Z direction to transfer the target die 51 from the pick-up head 31 to the bonding head 44. Here, when the pick-up head 31 picks up the target die 51, the bonded surface 51a of the target die 51 faces the +Z direction, and the bonded surface 51a comes into contact with the pick-up head 31. On the other hand, when the target die 51 is transferred from the pick-up head 31 to the bonding head 44, it is necessary that the bonded surface 51a of the target die 51 faces the -Z direction. Therefore, while the pickup head 31 is transporting the target die 51 to the bonding head 44, the pickup head 31 can be rotated so that the target die 51 is turned upside down (flip chip).

[0056] In the first embodiment, the pickup head 31 directly transports the target die 51 to the bonding head 44, but the present invention is not limited thereto. For example, when one or more transport mechanisms are provided on the transport path of the target die 51 to the bonding head 44, the target die 51 may be transported to the bonding head 44 through a process of transferring the target die 51 to the one or more transport mechanisms. In addition, a mechanism for performing a pre-processing for the bonding process on the target die 51 may be provided inside the bonding apparatus 100. Examples of the pre-processing include a process of applying an adhesive to the bonded surface 51a of the target die 51 in the case of bonding with an adhesive, and a process of activating the bonded surface 51a of the target die 51 in the case of hybrid bonding. As the pre-processing, a cleaning process of the target die 51 may be performed. The pre-processing may be performed during the transport of the target die 51 to the bonding head 44.

[0057] Through the above steps, the wafer 6 is held by the stage 43 and the target die 51 is held by the bonding head 44 .

[0058] Subsequently, in step S103, the control unit CNT performs die alignment using the die observation camera 45. In the die alignment, as shown in FIG. 3(a), the stage 43 on which the die observation camera 45 is mounted is driven to position the die observation camera 45 below the target die 51 held by the bonding head 44. Next, the bonded surface 51a of the target die 51 is imaged by the die observation camera 45, and the position of the pattern 501 (second pattern) provided on the bonded surface 51a of the target die 51 is obtained based on the image thus obtained.

[0059] The focus adjustment when imaging the bonded surface 51a of the target die 51 may be performed by a focus adjustment mechanism provided in the die observation camera 45, or may be performed by driving the die observation camera 45 in the Z direction by the Z drive mechanism of the stage 43. When the bonding head 44 is provided with a Z drive mechanism, the focus adjustment may be performed by driving the target die 51 in the Z direction by the Z drive mechanism of the bonding head 44. In addition, in the first embodiment, since the alignment mark 502 is provided on the bonded surface 51a of the target die 51, the position of the pattern 501 of the target die 51 can be obtained using the alignment mark 502. On the other hand, in a general die, the alignment mark is often disposed on the scribe line, and the alignment mark is often removed together with the scribe line. In this case, the position of the die pattern may be obtained using a portion of the bonded surface where the position of the pattern can be specified (hereinafter, may be referred to as a specifiable portion). Examples of identifiable locations include the very end of an array of pads or bumps arranged on the bonded surface, a region in a non-periodic array, or the outer edge (outer shape) of the die.

[0060] For example, the control unit CNT can measure the position of the pattern 501 of the target die 51 by measuring the image position of the projected alignment mark 502 or the identifiable location with respect to the center of the image acquired by the die observation camera 45. Measuring the position of the target die 51 can include measuring the amount of rotation (rotation in the θZ direction) of the target die 51. The amount of rotation of the target die 51 can be measured, for example, by determining the position of each of a plurality of identifiable locations on the bonded surface 51a of the target die 51 based on the image obtained by the die observation camera 45. The position of each of the plurality of identifiable locations can be determined based on a plurality of images obtained by individually imaging each identifiable location while driving the die observation camera 45 by the stage 43. Alternatively, when the entire target die 51 fits within the imaging field of the die observation camera 45, the position of each of the plurality of identifiable locations can be determined from an image obtained by imaging the entire bonded surface 51a of the target die 51 by the die observation camera 45. The amount of rotation of the target die 51 can be corrected by rotating the wafer 6 by the stage 43 during the bonding process. However, since the measurement range of the interferometer 47 in the θZ direction is narrow, if the amount of rotation of the target die 51 is large, it is desirable to rearrange the target die 51 on the bonding head 44 so that the amount of rotation of the target die 51 is corrected. When the target die 51 is rearranged on the bonding head 44, it is necessary to measure the position of the target die 51 again.

[0061] During the execution of step S103, the surface position of the target die 51 may be measured using a second height measuring means (not shown) for measuring the surface position of the bonded surface 51a of the target die 51. This is because the thickness of the target die 51 varies, and the surface position of the target die 51 is important for managing (controlling) the gap between the wafer 6 and the target die 51 with high accuracy during the bonding process. Furthermore, the heights of a plurality of positions on the bonded surface 51a of the target die 51 (i.e., the height distribution of the bonded surface 51a) may be measured, and the relative attitude between the wafer 6 and the target die 51 may be adjusted during the bonding process based on the measurement results. The adjustment of the relative attitude may be performed by a tilt mechanism mounted on the stage 43 and / or the bonding head 44.

[0062] Here, in step S103, the control unit CNT acquires positional relationship information using the die observation camera 45. The positional relationship information is information indicating the positional relationship between the characteristic part of the target die 51 and the pattern 501 of the target die 51, as described above. Also, the characteristic part of the target die 51 is an index that can be confirmed in both the image obtained by imaging the bonded surface 51a of the target die 51 and the image obtained by imaging the back surface 51b of the target die 51, as described above. The characteristic part of the target die 51 includes the outer edge (outer shape) of the target die 51 and / or the through via 503. For example, the control unit CNT can cause the die observation camera 45 to image the bonded surface 51a of the target die 51, and obtain the positional relationship between the characteristic part of the target die 51 in the image obtained thereby and the pattern 501 of the target die 51 as the positional relationship information. When the outer edge of the target die 51 is used as the characteristic part, the die observation camera 45 is preferably configured so that the entire target die 51 fits within the imaging field of view. In the first embodiment, in step S103, the positional relationship information is obtained using the die observation camera 45. However, the positional relationship information only needs to be obtained before the joining process (step S105) described later, and may be obtained in advance using an external device, for example.

[0063] In step S104, the control unit CNT aligns the wafer 6 and the target die 51 by driving the stage 43 so that the pattern of the wafer 6 and the pattern 501 of the target die 51 overlap with each other. Specifically, the control unit CNT drives the stage 43 so that the target area of ​​the wafer 6 to which the target die 51 should be bonded is disposed below the target die 51 held by the bonding head 44. Then, the control unit CNT aligns the wafer 6 and the target die 51 based on the position of the pattern of the wafer 6 obtained in step S102 and the position of the pattern 501 of the target die 51 obtained in step S103. At this time, it is preferable to align the wafer 6 and the target die 51 so that the relative rotational deviation and / or posture deviation between the wafer 6 and the target die is reduced. Furthermore, when the relative positions of the wafer 6 and the target die 51 in the XY directions change (shift) in a bonding process described later, the change in the relative positions may be used as an offset amount to align the wafer 6 and the target die 51. The offset amount can be obtained in advance by an experiment, a simulation, or the like.

[0064] In step S105, the control unit CNT bonds the target die 51 to the wafer 6 by narrowing the gap between the wafer 6 and the target die 51 (bonding process). The bonding process may be performed by driving the target die 51 in the Z direction by the bonding head 44, or by driving the wafer 6 in the Z direction by the stage 43. Alternatively, the bonding process may be performed by driving the target die 51 and the wafer 6 relatively in the Z direction by the bonding head 44 and the stage 43. In order to control the gap between the wafer 6 and the target die 51 with high accuracy, a detection unit (e.g., an encoder) that detects the position of the bonding head 44 and / or the stage 43 in the Z direction may be provided. In addition, in the bonding process, ultrasonic waves may be applied to the bonding head 44 and / or the stage 43 while the wafer 6 and the target die 51 are in contact with each other (i.e., ultrasonic bonding may be applied). After the wafer 6 and the target die 51 are bonded to each other, the control unit CNT releases the target die 51 from the bonding head 44 and widens the gap between the wafer 6 and the target die 51. The bonding process may be understood to include the alignment in step S104 described above.

[0065] Here, even during the bonding process, the relative positions of the wafer 6 and the target die 51 in the XY directions can be controlled to improve the alignment accuracy between the wafer 6 and the target die 51. For example, when controlling the relative positions of the wafer 6 and the target die 51 in the XY directions by driving the stage 43, the width of the mirror 433 in the Z direction may be set so that the light from the interferometer 47 is irradiated onto the mirror 433 even when the stage 43 is driven in the Z direction. Also, a detection unit (e.g., an encoder, a gap sensor) that detects the relative positions of the bonding head 44 and the stage 43 in the XY directions may be provided. In this case, feedback control of the relative positions can be performed while the detection unit detects (monitors) the relative positions of the bonding head 44 and the stage 43 in the XY directions during the bonding process. Note that if the wafer 6 and the target die 51 come into contact with each other, the position of the stage 43, which is feedback-controlled based on the measurement results of the interferometer 47, is constrained. Therefore, it is advisable to switch the control method of the relative positions between the wafer 6 and the target die 51 in the XY directions before and after the contact, for example, by stopping the feedback process when the wafer 6 starts to come into contact with the target die 51. In addition, in the case of bump bonding, a process required for bump bonding, such as pressing the target die 51 against the wafer 6 with a predetermined pressure (bonding pressure), can also be performed in step S105.

[0066] In step S106, the control unit CNT judges whether the die 51 has been bonded to all of the multiple target areas in the wafer 6. Usually, several tens to several hundreds of semiconductor devices are formed as multiple target areas in one wafer 6, and the die 51 can be bonded to each of the multiple target areas. If the target area (next target area) to which the die 51 should be bonded next exists in the wafer 6, the process returns to step S202. On the other hand, if the next target area does not exist in the wafer 6, that is, if the die 51 has been bonded to all of the multiple target areas in the wafer 6, the process proceeds to step S107.

[0067] Here, in the first embodiment, an example has been described in which it is determined whether or not there is a next target area after the bonding process and the process returns to step S202, but the determination of whether or not there is a next target area may be performed before the end of the bonding process. In this case, step S202 may be performed in parallel with the execution of the bonding process. That is, in parallel with the execution of the bonding process, the die 51 to be bonded to the next target area is picked up from the dicing frame 5 (dicing tape). Also, when multiple types of die 51 are bonded to each target area (semiconductor device) on the wafer 6, bonding of one type of die is performed on all of the target areas on the wafer 6, and then bonding of the next type of die is started. When bonding of the next type of die is started, a carry-in operation (step S201) of the dicing frame 5 on which the next type of die is arranged is performed, and then die pick-up of step S202 may be performed.

[0068] In step S107, the control unit CNT performs an estimation process to estimate a relative position between the pattern of the wafer 6 after the bonding process and the pattern 501 of the target die 51. The estimation process may include steps S107a to S107c. In the first embodiment, the estimation process may be performed on each of a plurality of target regions in the wafer 6, that is, on each of a plurality of dies 51 bonded to the wafer 6.

[0069] In step S107a, the control unit CNT captures an image of the appearance of the die 51 bonded to the wafer 6 by the wafer observation camera 46, as shown in FIG. 3(a). The image thus obtained includes the back surface 51b of the die 51 bonded to the wafer 6 and a part of the wafer 6 around the die 51. Next, in step S107b, the control unit CNT acquires feature position information based on the image obtained in step S107a. As described above, the feature position information is information indicating the position of the feature of the die 51 relative to the wafer 6. The feature of the die 51 includes the outer edge (outline) of the die 51 and / or the through via 503, and in step S107b, the position of the feature on the back surface 51b of the die 51 is obtained.

[0070] In step S107c, the control unit CNT estimates (calculates) the relative position between the pattern of the wafer 6 and the pattern 501 of the die 51 after the bonding process, based on the feature position information obtained in step S107b and the positional relationship information obtained in step S103. Specifically, the control unit CNT can estimate the relative position by converting the position of the feature of the die 51 in the feature position information into the position of the pattern 501 of the die 51, based on the positional relationship information.

[0071] In step S107d, the control unit CNT outputs the estimation result in step S107c. The estimation result may be output by displaying information of the estimation result on a user interface (e.g., a display) of the bonding apparatus 100, or by transmitting the information of the estimation result to an external computer. In addition, the control unit CNT may output, as the estimation result, information indicating the relative position between the pattern of the wafer 6 and the pattern 501 of the die 51 after the bonding process (e.g., numerical information indicating the deviation of the relative position), or may output information indicating an evaluation result of the relative position. The evaluation result may be, for example, a result of evaluating whether or not the deviation of the estimated relative position is within an allowable range.

[0072] FIG. 5 is a diagram showing a schematic diagram of bonding between the wafer 6 and the die 51. FIG. 5(a) shows the surface to be bonded of the target area 6a of the wafer 6, and the pattern 601 is represented by nine circles. FIG. 5(b) shows the surface to be bonded of the die 51, and the pattern 501 is represented by lines. FIG. 5(c) shows the relative positions of the pattern 601 of the wafer 6 and the pattern 501 of the die 51 recognized by the control unit CNT in the alignment of step S104. In the alignment of step S104, the control unit CNT recognizes the relative positions based on the position of the pattern 601 of the wafer 6 obtained in advance in step S102 and the position of the pattern 501 of the die 51 obtained in advance in step S103. That is, the control unit CNT does not actually observe the pattern 601 of the wafer 6 and the pattern 501 of the die 51 in the alignment of step S104. 5(d) shows the relative position between the pattern 601 of the wafer 6 and the pattern 501 of the die 51 after the bonding process. In the following, the relative position between the pattern 601 of the wafer 6 and the pattern 501 of the die 51 may be simply referred to as the "relative position."

[0073] (Case 1) in FIG. 5 is an ideal state in which the relative position recognized by the control unit CNT in the alignment coincides with the relative position after the bonding process. However, in reality, as shown in (Case 2) to (Case 4) in FIG. 5, an error may occur between the relative position recognized by the control unit CNT in the alignment and the relative position after the bonding process. According to the first embodiment, the relative position after the bonding process can be easily and accurately estimated by the estimation process in step S107. Such an estimation result of the relative position after the bonding process may be used, for example, to grasp (recognize) the bonding state between the wafer 6 and the die 51, or may be used as feedback to the bonding process to be performed later.

[0074] In step S108, the control unit CNT uses a wafer transport mechanism (not shown) to carry the wafer 6 with the die 51 bonded thereto out of the stage 43 (chuck 431). The wafer 6 may be returned to the FOUP used to carry the wafer 6 in or to a container other than the FOUP. However, since the overall thickness of the wafer 6 with the die 51 bonded thereto changes, it is preferable to return the wafer 6 to a different container. The above describes the operation flow of the bonding device 100 for bonding the die 51 to one wafer 6, but when bonding the die 51 to each of a plurality of wafers 6, the flowchart of FIG. 4 is repeated.

[0075] In addition, since the number of dies 51 on the dicing frame 5 and the number of target areas on the wafer 6 generally differ, the loading of the wafer 6 and the loading of the dicing frame 5 are often not synchronized. When the dies 51 on the dicing frame 5 run out during bonding of the dies 51 to one wafer 6, the next dicing frame 5 can be loaded into the bonding apparatus 100. On the other hand, if the dies 51 remain on the dicing frame 5 even after bonding of the dies 51 to one wafer 6 is completed, the remaining dies 51 can be used for the next wafer 6.

[0076] Here, in the flowchart of FIG. 4, after the judgment of step S106, the estimation process of step S107 is performed on each of the multiple target areas on the wafer 6 (i.e., each of the multiple dies 51 bonded to the wafer 6). However, as shown in the flowchart of FIG. 6, the estimation process of step S107 may be performed on the die 51 bonded to the wafer 6 in the bonding process immediately after the bonding process of step S105. This is for the purpose of reducing unnecessary waiting time when waiting time occurs in the bonding unit 4, such as when it takes time to pick up the die 51 in step S202. In this way, the bonding process of step S105 and the estimation process of step S107 may be flexibly switched or exchanged depending on the timing of picking up the die 51 in step S202. Also, depending on the bonding method, it may take a certain amount of time until the bonded state of the die 51 on the wafer 6 is stabilized after the bonding process of step S105. For example, the appropriate time may be the curing time of the adhesive in the case of adhesive bonding, or the time required for covalent bonding at the activated bonding surface from start to finish in the case of room temperature bonding using a surface activation method. If the estimation process in step S107 is performed before the bonding state is stabilized, an error may occur between the final bonding state and the estimation result. In order to deal with such a case, it is preferable to provide an arbitrary delay time between the bonding process in step S105 and the estimation process in step S107 in FIG. 6. Note that steps S101 to S108 in FIG. 6 are similar to steps S101 to S108 in FIG. 4, respectively, and therefore detailed description thereof will be omitted here.

[0077] [Example 2] In the second embodiment, a method for handling the estimation result obtained in step S107 described in the first embodiment will be described. That is, an example of outputting the estimation result in step S107d will be described. Note that the second embodiment basically follows the first embodiment, and can follow the first embodiment except for the matters mentioned below.

[0078] The simplest way to handle the estimation result is to display the estimation result in step S107 on the user interface (for example, a display) of the bonding apparatus 100 as information indicating the bonding accuracy between the pattern of the wafer 6 and the pattern of the die 51. The estimation result may be output as additional information of the wafer 6 carried out in step S108. The estimation result may be displayed on the user interface as information indicating the bonding accuracy of all or some of the dies 51 bonded on the wafer 6. In addition, in many semiconductor manufacturing sites, in addition to the bonding apparatus 100, manufacturing devices and processing devices for performing other processes are connected by a network, and information is exchanged between these devices online. The bonding apparatus 100 may also notify information indicating the bonding accuracy of all or some of the dies bonded on the wafer online, or may output information indicating the bonding accuracy online at any time in response to an information request from online. In addition, all information obtained in each process of the flowcharts of FIG. 4 and FIG. 6 described in the first embodiment can also be output online.

[0079] As described above, the bonding apparatus 100 of this embodiment performs a bonding process between the wafer 6 (first member) and the die 51 (second member) and then causes the wafer observation camera 46 (first imaging unit) to capture an image of the appearance of the die 51 bonded to the wafer 6. Then, based on the characteristic position information obtained from the image obtained by the wafer observation camera 46 and the positional relationship information acquired in advance, the relative positions of the pattern of the wafer 6 and the pattern of the die 51 after the bonding process are estimated. This makes it possible to easily and accurately obtain the pattern of the wafer 6 and the pattern of the die 51 after the bonding process.

[0080] <Second embodiment> A second embodiment of the present invention will be described. This embodiment basically follows the first embodiment, and can follow the first embodiment except for the points mentioned below.

[0081] Fig. 7 is a schematic diagram showing a bonding apparatus 100' of the second embodiment. The bonding apparatus 100 of this embodiment includes a die recovery section 61 (second recovery container) that recovers dies 51 that have been poorly bonded in the bonding section 4. Note that the bonding apparatus 100' of this embodiment has the same configuration as the bonding apparatus 100 of the first embodiment except for including the die recovery section 61, so that a description of the components other than the die recovery section 61 will be omitted here. Also, the pickup section 3 and the control section CNT are not shown in Fig. 7.

[0082] The die recovery unit 61 has a structure capable of receiving the die 51 from the pick-up head 31, and may be configured to hold (store) the multiple dies 51 received from the pick-up head 31. The die recovery unit 61 may be mounted on the base 1 on which the bonding unit 4 is mounted, or may be mounted on another base, or may be a mechanism independent of other components. The die recovery unit 61 may be configured to be easily detached from the bonding apparatus 100'. For example, the die recovery unit 61 may be configured to be detached from the bonding apparatus 100' while the recovered die 51 remains in a stored state. An example of this embodiment will be described below.

[0083] [Example 3] Fig. 8 is a flowchart showing an operation flow of the bonding device 100' in Example 3. Each step of the flowchart in Fig. 8 can be executed by the control unit CNT. Note that steps S101 to S108 and S201 to S203 in the flowchart in Fig. 8 are the same as those described in the first embodiment using the flowcharts in Fig. 4 and Fig. 6, and therefore detailed description thereof will be omitted here.

[0084] In step S301, the control unit CNT judges whether or not the deviation of the relative position between the pattern of the wafer 6 and the pattern 501 of the target die 51 after the bonding process is within the allowable range based on the estimation result in the estimation process in step S107. The allowable range may be set in advance based on, for example, the line width or dimensions of the pattern of the wafer 6 and / or the pattern of the target die 51. The allowable range may be set based on the electrical characteristics of the bonded material between the wafer 6 and the target die 51. If the deviation of the relative position is within the allowable range, the process proceeds to step S106, and if the deviation of the relative position is not within the allowable range, the process proceeds to step S302. Note that the die 51 whose deviation of the relative position is not within the allowable range may be understood as a die 51 whose bonding is poor. In the following, the die 51 whose deviation of the relative position is not within the allowable range may be referred to as a "die 51 whose bonding is poor."

[0085] In step S302, the control unit CNT separates the defectively bonded die 51 from the wafer 6 (separation process). Specifically, the control unit CNT drives the stage 43 so that the defectively bonded die 51 on the wafer 6 is disposed below the bonding head 44. Next, the control unit CNT narrows the gap between the bonding head 44 and the wafer 6 (defectively bonded die 51), and when the defectively bonded die 51 and the bonding head 44 come into contact with each other, causes the bonding head 44 to hold (pick up) the die 51. Then, while the bonding head 44 holds the defectively bonded die 51, the control unit CNT widens the gap between the bonding head 44 and the wafer 6. This allows the defectively bonded die 51 to be separated from the wafer 6.

[0086] This separation process focuses on the fact that the die 51 can be separated from the wafer 6 before the bonding between the wafer 6 and the die 51 is complete. In other words, the separation process can be performed before the bonding between the wafer 6 and the die 51 is complete. For example, in room temperature bonding using a surface activation method, the covalent bond between molecules does not start unless the gap between the wafer 6 and the die 51 is on the order of 0.1 nm or less, and the state is maintained just before the complete bonding state, so that it is possible to separate the die 51 from the wafer 6. In room temperature bonding using a surface activation method, the gap between the wafer 6 and the die 51 does not generally become on the order of 0.1 nm or less unless the die 51 is pressed onto the wafer 6. Therefore, in room temperature bonding using a surface activation method, the estimation process of step S107 is performed before the die 51 is pressed onto the wafer 6, and the die 51 can be pressed onto the wafer 6 according to the estimation result. If the estimation result is good (i.e., the deviation in relative position is within the allowable range), the die 51 is pressed onto the wafer 6, and if the estimation result is bad (i.e., the deviation in relative position is outside the allowable range), a separation process can be performed. In addition, in adhesive bonding, before the adhesive hardens, it is in a state immediately before a complete bonding state is reached, so it is possible to separate the die 51 from the wafer 6. The separation process in step S302 is performed at a timing when the bonded state can be released, depending on the bonding method.

[0087] In step S303, the control unit CNT passes (transfers) the die 51 held by the bonding head 44 to the pick-up head 31. Specifically, the control unit CNT drives the pick-up head 31 in the X direction to place the pick-up head 31 below the bonding head 44. Then, the control unit CNT passes the die 51 from the bonding head 44 to the pick-up head 31 by driving the pick-up head 31 in the +Z direction.

[0088] In step S304, the control unit CNT moves the pick-up head 31 to the die recovery unit 61, and transfers the die 51 held by the pick-up head 31 to the die recovery unit 61. This completes the separation and recovery of the defectively bonded die 51. After step S304 is completed, the process proceeds to step S106. Note that a bonding process for a new die 51 may be performed again on the target area of ​​the wafer 6 from which the bonded die 51 was separated.

[0089] [Example 4] Fig. 9 is a flowchart showing an operation flow of the bonding device 100' in Example 4. Each step of the flowchart in Fig. 9 can be executed by the control unit CNT. Note that steps S101 to S108 and S201 to S203 in the flowchart in Fig. 9 are the same as those described in the first embodiment using the flowcharts in Fig. 4 and Fig. 6, and therefore detailed description thereof will be omitted here.

[0090] In step S301, the control unit CNT judges whether or not the relative positional deviation between the pattern of the wafer 6 after the bonding process and the pattern 501 of the target die 51 is within an allowable range based on the estimation result in the estimation process in step S107. Next, in step S302, the control unit CNT separates the defectively bonded die 51 from the wafer 6 (separation process). Steps S301 to S302 are as described in the third embodiment, and therefore detailed description thereof will be omitted here.

[0091] In step S401, the control unit CNT re-bonds the die 51 separated from the wafer 6 in step S302 onto the wafer 6. Specifically, the control unit CNT realigns the wafer 6 and the die 51 so that the amount of deviation of the relative position is corrected based on the amount of deviation of the relative position estimated in step S107. Then, the control unit CNT re-bonds the die 51 to the wafer 6 by narrowing the gap between the wafer 6 and the die 51. This process makes it possible to re-bond the die 51 to the wafer 6 so that the deviation of the relative position between the pattern of the wafer 6 and the pattern of the die 51 that occurred during the first bonding is corrected. After the die 51 is re-bonded to the wafer 6, the process proceeds to step S107.

[0092] As described above, in this embodiment, based on the estimation result in the estimation process in step S107, it is determined whether or not the deviation in the relative position between the pattern of the wafer 6 and the pattern of the die 51 after the bonding process is within the allowable range. Then, if the deviation in the relative position is not within the allowable range, the die 51 is separated from the wafer 6. This makes it possible to bond a new die 51 to the target area of ​​the wafer 6 from which the die 51 was separated, or to re-bond the separated die 51.

[0093] <Embodiments of the method for manufacturing an article> A method for manufacturing an article (such as a semiconductor IC element, a liquid crystal display element, or a MEMS) using the above-mentioned bonding apparatus will be described. The method for manufacturing an article according to the embodiment of the present invention is suitable for manufacturing an article such as a microdevice such as a semiconductor device or an element having a fine structure. The method for manufacturing an article according to the present embodiment includes a step of bonding a second member to a first member using the above-mentioned bonding apparatus, a step of processing the first member to which the second member is bonded, and a step of manufacturing an article from the processed first member. In the above-mentioned bonding apparatus, the bonding state between the first member and the second member can be easily and accurately grasped by estimating the relative position between the pattern of the first member and the pattern of the second member after the bonding process. In addition, it is possible to re-bond the die in the bonding apparatus based on the estimation result of the relative position. Furthermore, it is also possible to reflect the information on the estimation result of the relative position in a subsequent process. The subsequent process here refers to other well-known processes, and includes probing, dicing, bonding, packaging, and the like. The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article compared to conventional methods.

[0094] <Summary of the embodiment> The disclosure of the present specification includes the following bonding apparatus, bonding method, and method for manufacturing an article.

[0095] (Item 1) A joining device that joins a second member having a second joined surface provided with a second pattern to a first member having a first joined surface provided with a first pattern, A first imaging unit that images the first joined surface of the first member; A second imaging unit that images the second joined surface of the second member; a control unit that controls a joining process of joining the second member to the first member by aligning the first member and the second member based on a position of the first pattern in the image obtained by the first imaging unit and a position of the second pattern in the image obtained by the second imaging unit; Equipped with The control unit, after the joining process, acquiring characteristic position information indicating a position of a characteristic portion of the second member relative to the first member based on an image obtained by imaging the second member joined to the first member with the first imaging unit; a joining device that estimates a relative position of the first pattern and the second pattern after the joining process based on positional relationship information indicating a positional relationship between the characteristic portion of the second component and the second pattern that has been acquired in advance and the characteristic position information.

[0096] (Item 2) 2. The joining device according to item 1, wherein the characteristic portion of the second member is an index that can be confirmed in both an image obtained by imaging the second joining surface and an image obtained by imaging a surface opposite to the second joining surface.

[0097] (Item 3) 3. The joining device according to item 1 or 2, characterized in that the characteristic portion of the second member is an outer edge of the second member.

[0098] (Item 4) 3. The joining device according to item 1 or 2, characterized in that the characteristic portion of the second member is a through hole that penetrates from the second joined surface to a surface opposite the second joined surface.

[0099] (Item 5) 5. The joining device according to any one of items 1 to 4, wherein the control unit acquires the feature position information based on an image obtained by the second imaging unit before the joining process.

[0100] (Item 6) The joining device described in any one of items 1 to 5, characterized in that the control unit estimates the relative position by converting a position of the characteristic portion of the second member in the characteristic position information into a position of the second pattern based on the positional relationship information.

[0101] (Item 7) The joining device according to any one of items 1 to 6, wherein the control unit outputs information indicating the relative position estimated based on the positional relationship information and the characteristic position information.

[0102] (Item 8) The joining device according to any one of items 1 to 6, wherein the control unit outputs an evaluation result of the relative position estimated based on the positional relationship information and the characteristic position information.

[0103] (Item 9) The joining device described in any one of items 1 to 8, characterized in that the control unit executes a separation process to separate the second member from the first member depending on an evaluation result of the relative position estimated based on the positional relationship information and the characteristic position information.

[0104] (Item 10) A first holding portion that holds the first member; A second holding portion that holds the second member, 10. The bonding apparatus according to any one of claims 1 to 9, wherein the control unit controls the bonding process by driving the first holding unit and the second holding unit relatively to each other.

[0105] (Item 11) the first imaging unit is disposed so as to be able to image the first joined surface of the first member in a state in which the first member is held by the first holding unit, Item 11. The joining device according to item 10, characterized in that the second imaging unit is positioned so as to be able to image the second joined surface of the second member in a state in which the second member is held by the second holding unit.

[0106] (Item 12) A method for joining a second member having a second joined surface provided with a second pattern to a first member having a first joined surface provided with a first pattern, comprising: a first imaging step of imaging the first joined surface of the first member; a second imaging step of imaging the second joined surface of the second member; a joining process of joining the second member to the first member by aligning the first member and the second member based on a position of the first pattern in the image obtained in the first imaging process and a position of the second pattern in the image obtained in the second imaging process; an acquisition step of acquiring, after the joining step, characteristic position information indicating a position of a characteristic portion of the second member relative to the first member, based on an image obtained by imaging the second member joined to the first member; an estimation step of estimating a relative position between the first pattern and the second pattern after the first member and the second member are joined based on positional relationship information indicating a positional relationship between the characteristic portion of the second member and the second pattern, which has been acquired in advance, and the characteristic position information; A bonding method comprising the steps of:

[0107] (Item 13) A step of joining a second member to a first member using the joining method according to item 12; processing the first member to which the second member is joined; producing an article from the processed first member; A method for producing an article, comprising:

[0108] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0109] 3: Pickup section, 31: Pickup head, 32: Release head, 4: Bonding section, 43: Stage, 44: Bonding head, 45: Die observation camera, 46: Wafer observation camera, 5: Dicing frame, 51: Die, 6: Wafer

Claims

A bonding device for bonding a second member to a first member, comprising: a first imaging unit; a control unit configured to obtain information regarding the relative position between the first member and the second member based on an image obtained by the first imaging unit capturing the second member bonded to the first member; A bonding device characterized by comprising the above. The bonding device according to claim 1, further comprising a second imaging unit configured to image a second pattern provided on the second member, wherein the first imaging unit images a first pattern provided on the first member, and the control unit obtains information regarding the relative position between the first member and the second member based on the position of the first pattern in the image obtained by the first imaging unit and the position of the second pattern in the image obtained by the second imaging unit, and controls a bonding process of aligning the first member and the second member based on the obtained information regarding the relative position between the first member and the second member and bonding the second member to the first member. The bonding device according to claim 1, characterized by the above. The bonding device according to claim 2, wherein the information regarding the relative position includes information on the relative position between the first pattern and the second pattern. The control unit of the bonding device according to claim 4 obtains characteristic position information indicating the position of a characteristic portion of the second member, and obtains information on the relative position between the first pattern and the second pattern after the bonding process based on position relationship information indicating the positional relationship between the characteristic portion and the second pattern obtained in advance and the characteristic position information. Claim 5 The characteristic portion of the second member is an index that can be confirmed in both an image obtained by imaging a second bonded surface, which is a surface to be bonded of the second member, and an image obtained by imaging a surface on the opposite side of the second bonded surface. Claim 6 The characteristic portion of the second member is an outer edge of the second member. Claim 7 The characteristic portion of the second member is a through hole that penetrates from a second bonded surface, which is a surface to be bonded of the second member, to a surface on the opposite side of the second bonded surface. Claim 8 The control unit obtains the characteristic position information based on an image obtained by the second imaging unit before the bonding process. Claim 9 The control unit acquires the relative position by converting the position of the feature portion of the second member in the feature position information to the position of the second pattern based on the position relationship information. The bonding device according to claim 4, characterized in that.

10. The control unit outputs information indicating the relative position acquired based on the position relationship information and the feature position information. The bonding device according to claim 4, characterized in that.

11. The control unit outputs an evaluation result of the relative position acquired based on the position relationship information and the feature position information. The bonding device according to claim 4, characterized in that.

12. The control unit executes a separation process of separating the second member from the first member according to the evaluation result of the relative position acquired based on the position relationship information and the feature position information. The bonding device according to claim 4, characterized in that.

13. A first holding unit that holds the first member, A second holding unit that holds the second member, and further includes, The control unit controls the bonding process by relatively driving the first holding unit and the second holding unit. The bonding device according to claim 2, characterized in that.

14. The first imaging unit is disposed so as to be able to image a first bonded surface that is a bonded surface of the first member in a state where the first member is held by the first holding unit, The second imaging unit is disposed so as to be able to image a second bonded surface that is a bonded surface of the second member in a state where the second member is held by the second holding unit. The bonding device according to claim 13, characterized in that.

15. A bonding method for bonding a second member to a first member, comprising: A bonding step of bonding the second member to the first member; An acquisition step of acquiring information regarding the relative position between the first member and the second member based on an image obtained by imaging the second member bonded to the first member after the bonding step; A bonding method characterized by including.

16. A step of bonding a second member to a first member using the bonding method according to claim 15; A step of processing the first member to which the second member is bonded; A step of manufacturing an article from the processed first member; A method for manufacturing an article, characterized by including.

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