Joining device and joining method

Abstract

To provide a joining device and a joining method, capable of performing activation treatment uniformly on the entire joint surface of an abject to be joined.SOLUTION: A joining device includes: a stage 141 holding a substrate W1; a head 142 arranged to face the stage 141 and holding a substrate W2; a particle beam source 161 fixed to the stage 141 and radiating a particle beam to a region including a part of a joint surface of the substrate W2 from the outside of a region where the substrate W1 is arranged in the stage 141; and a head drive section 144 moving the head 142 in a first direction where the substrates W1, W2 approach to each other or a second direction where the substrates W1, W2 separate from each other.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] A method has been proposed in which a surface activation treatment is performed by irradiating particle beams onto the bonding surfaces of a pair of substrates to activate each of the bonding surfaces of the pair of substrates, and then the pair of substrates are bonded by bringing the bonding surfaces of the pair of substrates into contact with each other (see, for example, Patent Document 1). In this method, in a chamber, stages holding the pair of substrates are arranged in a state of being separated from each other, and particle beams are irradiated from a particle beam source fixed at a fixed position in the chamber toward the bonding surfaces of the substrates held by the stages, thereby activating the bonding surfaces of the substrates.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the method described in Patent Document 1, the irradiation direction of the particle beam is inclined with respect to the bonding surface of the substrate, resulting in non-uniform particle beam doses incident on the substrate in the direction parallel to the incident plane of the particle beam on the substrate. In addition, a particle beam source may be used that has a discharge chamber that is linear in shape and positioned so that its longitudinal direction is parallel to the bonding surface of the substrate. However, in the case of such a particle beam source, the plasma density generated in the discharge chamber becomes non-uniform in the longitudinal direction of the discharge chamber, and consequently, the particle beam dose in the direction perpendicular to the incident plane of the particle beam on the bonding surface of the substrate becomes non-uniform. Thus, if the particle beam dose incident on the bonding surface of the substrate becomes non-uniform in the direction parallel to the incident plane of the particle beam and in the direction perpendicular to the incident plane, there is a risk that the entire bonding surface cannot be activated uniformly.

[0005] The present invention has been made in view of the above reasons, and aims to provide a joining apparatus and joining method that can uniformly activate the entire joining surface of objects to be joined. [Means for solving the problem]

[0006] To achieve the above objective, the joining apparatus according to the present invention is A joining device for joining two objects to be joined, A first workpiece holding unit that holds one of the two workpieces to be joined, A second workpiece holding portion is positioned opposite the first workpiece holding portion and holds the other of the two workpieces to be joined, A first particle beam source is fixed to the first workpiece holding portion and emits a particle beam from outside the region in the first workpiece holding portion where one workpiece is placed to a region including a part of the joining surface of the other workpiece. The device includes a drive unit that moves at least one of the first workpiece holding unit and the second workpiece holding unit in a first direction in which the first workpiece holding unit and the second workpiece holding unit move closer together, or in a second direction in which the first workpiece holding unit and the second workpiece holding unit move further apart. [Effects of the Invention]

[0007] According to the present invention, the entire bonding surface of the joined objects can be uniformly activated. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic front view of a joining device according to an embodiment of the present invention. [Figure 2] This figure shows a part of the joining device according to the embodiment. [Figure 3] This is a schematic front view of the discharge chamber according to the embodiment. [Figure 4A] This figure shows a part of the bonding apparatus according to the embodiment, representing the state in which the stage-head distance is at its shortest. [Figure 4B] This figure shows a part of the bonding apparatus according to the embodiment, representing the state in which the stage-head distance is at its longest. [Figure 5A] This figure shows the irradiation area of ​​the particle beam in the stage according to the embodiment. [Figure 5B] This figure shows the irradiation area of ​​the particle beam in the head according to the embodiment. [Figure 6] This is an explanatory diagram of the operation of the joining device according to the embodiment. [Figure 7] This is a schematic front view of the discharge chamber according to Comparative Example 1. [Figure 8] This figure shows the locations on the substrate used to measure the film thickness for evaluating the uniformity of the particle beam dose during the activation process. [Figure 9A] This figure shows the film thickness distribution of the SiO2 film before and after the activation treatment for Comparative Example 1, and is a diagram showing the film thickness distribution in the P-axis direction of Figure 8. [Figure 9B]It is a diagram showing the film thickness distribution of the SiO2 film before and after the activation treatment according to Comparative Example 1, and showing the film thickness distribution in the Q-axis direction in FIG. 8. [Figure 10A] It is a diagram showing the film thickness distribution of the SiO2 film before and after the activation treatment according to Comparative Example 1, and showing the film thickness distribution in the P-axis direction in FIG. 8. [Figure 10B] It is a diagram showing the film thickness distribution of the SiO2 film before and after the activation treatment according to Comparative Example 1, and showing the film thickness distribution in the Q-axis direction in FIG. 8. [Figure 11A] It is a diagram showing the film thickness distribution of the SiO2 film before and after the activation treatment according to the embodiment, and showing the film thickness distribution in the P-axis direction in FIG. 8. [Figure 11B] It is a diagram showing the film thickness distribution of the SiO2 film before and after the activation treatment according to the embodiment, and showing the film thickness distribution in the Q-axis direction in FIG. 8. [Figure 12A] It is a diagram showing the film thickness distribution of the SiO2 film before and after the activation treatment according to the embodiment, and showing the film thickness distribution in the P-axis direction in FIG. 8. [Figure 12B] It is a diagram showing the film thickness distribution of the SiO2 film before and after the activation treatment according to the embodiment, and showing the film thickness distribution in the Q-axis direction in FIG. 8. [Figure 13A] It is a diagram showing a part of the bonding device according to Comparative Example 2. [Figure 13B] It is a diagram showing the distribution of the dose amount when the substrate is irradiated with a particle beam by the bonding device according to Comparative Example 2. [Figure 14] It is a schematic diagram of the plasma distribution in the particle beam source according to Comparative Examples 1 and 2 and the embodiment. [Figure 15] It is a diagram showing a part of the bonding device according to the modified example. [Figure 16] It is an operation explanatory diagram of the bonding device according to the modified example. [Figure 17] It is a schematic front view of the discharge chamber according to the modified example.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, a bonding apparatus according to Embodiment 1 of the present invention will be described with reference to the figures. In this embodiment, the bonding apparatus performs an activation treatment on the bonding surfaces of two substrates in a chamber under reduced pressure, and then bonds the two substrates by bringing them into contact and applying pressure. Here, the substrates are, for example, glass substrates such as Si substrates and SiO2 glass substrates, oxide substrates (for example, silicon oxide (SiO2) substrates, alumina substrates including sapphire substrates (Al2O3), gallium oxide (Ga2O3), etc.), nitride substrates (for example, silicon nitride (SiN), aluminum nitride (AlN), gallium nitride (GaN)), GaAs substrates, silicon carbide (SiC) substrates, lithium tantalate (Lt:LiTaO3) substrates, lithium niobate (Ln:LiNbO3) substrates, diamond substrates, etc. Alternatively, the substrates W1 and W2 may be substrates on which electrodes made of metals such as Au, Cu, Al, and Ti are provided on the bonding surface. Furthermore, it is preferable that substrates W1 and W2 are circular in plan view with a diameter of 6 inches or less. In the activation treatment, the bonding surfaces of the two substrates are activated by irradiating them with a particle beam. The substrates may be heated before the activation treatment, or they may be heated when the two substrates are brought into contact and pressurized.

[0010] The bonding apparatus according to this embodiment, as shown in Figure 1, comprises a chamber 120, a stage 141, a head 142, a stage drive unit 143, a head drive unit 144, substrate heating units 1411 and 1421, a positional displacement measurement unit 150, and particle beam sources 161 and 162. In the following description, the ±Z direction in Figure 2 will be used as the vertical direction and the XY direction as the horizontal direction. The chamber 120 is connected to the vacuum pump 121a via an exhaust pipe 121b and an exhaust valve 121c. When the exhaust valve 121c is opened and the vacuum pump 121a is operated, the gas inside the chamber 120 is discharged outside the chamber 120 through the exhaust pipe 121b, and the air pressure inside the chamber 120 is reduced (depressurized). The air pressure inside the chamber 120 is 10 -5The pressure can be reduced to below Pa. Furthermore, the air pressure (vacuum level) inside the chamber 120 can be adjusted by varying the opening and closing amount of the exhaust valve 121c to control the exhaust volume.

[0011] The stage 141 and the head 142 are arranged in the chamber 120 so as to face each other in the Z direction. The stage 141 is a first workpiece holding part that holds the substrate W1 on its upper surface, and the head 142 is a second workpiece holding part that holds the substrate W2 on its lower surface. The upper surface of the stage 141 and the lower surface of the head 142 may be roughened to account for cases where the contact surfaces of the substrates W1 and W2 with the stage 141 and head 142 are mirror-finished and difficult to peel off from the stage 141 and head 142. The stage 141 and the head 142 each have a holding mechanism (not shown) for holding the substrates W1 and W2. The holding mechanism may be an electrostatic chuck, a mechanical clamp, etc. The stage 141 also has a shape in which a stepped portion 141a is formed on its periphery. When the substrates W1 and W2 are placed on the stage 141, the periphery of the substrates W1 and W2 is positioned above the stepped portion 141a.

[0012] The stage drive unit 143 can move the stage 141 in the XY direction or rotate it around the Z axis.

[0013] The head drive unit 144 includes a lifting drive unit 1441 for raising and lowering the head 142 as shown by arrow AR1, an XY direction drive unit 1442 for moving the head 142 in the XY direction, and a rotation drive unit 1443 for rotating the head 142 in the rotational direction around the Z axis. The head drive unit 144 also includes a piezo actuator 1444 for adjusting the tilt of the head 142 relative to the stage 141, and a pressure sensor 1445 for measuring the pressure applied to the head 142. The XY direction drive unit 1442 and the rotation drive unit 1443 move the head 142 relative to the stage 141 in the X direction, Y direction, and rotational direction around the Z axis, thereby enabling alignment between the substrate W1 held on the stage 141 and the substrate W2 held on the head 142. Furthermore, the stage drive unit 143 is not limited to being positioned vertically below the stage 141. For example, a backup unit (not shown) that receives pressure may be provided vertically below the stage 141, and the stage drive unit 143 may be positioned on the outer periphery of the stage 141 to drive the stage 141 from the side.

[0014] The lifting drive unit 1441 moves the head 142 vertically downward, bringing it closer to the stage 141. The lifting drive unit 1441 also moves the head 142 vertically upward, moving it away from the stage 141. When the substrates W1 and W2 are in contact, the lifting drive unit 1441 applies a driving force to the head 142 in the direction of approaching the stage 141, causing substrate W2 to be pressed against substrate W1. The lifting drive unit 1441 is also equipped with a pressure sensor 1441a to measure the driving force applied to the head 142 in the direction of approaching the stage 141. From the measurement value of the pressure sensor 1441a, the pressure acting on the bonding surface of substrates W1 and W2 when substrate W2 is pressed against substrate W1 by the lifting drive unit 1441 can be detected. The pressure sensor 1441a may, for example, have a piezoelectric element.

[0015] Multiple sets of piezo actuators 1444 and pressure sensors 1445 are arranged between the head 142 and the XY direction drive unit 1442. The pressure sensors 1445 are interposed between the upper end of the piezo actuator 1444 and the lower side of the XY direction drive unit 1442. Each piezo actuator 1444 can extend and retract individually in the vertical direction, and by extending and retracting them, the tilt of the head 142 around the X and Y axes and the vertical position of the head 142 are finely adjusted. The pressure sensors 1445, for example, have piezoelectric elements and measure the applied pressure at multiple points on the lower surface of the head 142. By driving each of the multiple piezo actuators 1444 so that the applied pressure measured by the multiple pressure sensors 1445 is equal, the lower surface of the head 142 and the upper surface of the stage 141 can be kept parallel while the substrates W1 and W2 can be brought into contact with each other.

[0016] The substrate heating units 1411 and 1421 are, for example, when the aforementioned holding mechanism is an electrostatic chuck, first workpiece heating units having electric heaters embedded on the back side of the holding mechanism on the stage 141 and head 142, as viewed from the side where the substrates W1 and W2 are in contact. The substrate heating units 1411 and 1421 heat the substrates W1 and W2 by transferring heat to the substrates W1 and W2 supported by the stage 141 and head 142. Furthermore, the temperature of the substrates W1 and W2 or their bonding surface can be adjusted by adjusting the amount of heat generated by the substrate heating units 1411 and 1421. The misalignment measurement unit 150 measures the amount of horizontal misalignment of substrate W1 relative to substrate W2 by recognizing the position of alignment marks provided on each of the substrates W1 and W2. The misalignment measurement unit 150 recognizes the alignment marks on substrates W1 and W2 using, for example, light transmitted through the substrates W1 and W2 (e.g., infrared light). The stage drive unit 143 performs alignment operations between the substrates W1 and W2 by moving or rotating the stage 141 horizontally based on the amount of misalignment measured by the misalignment measurement unit 150.

[0017] The particle beam sources 161 and 162 are, for example, fast atomic beam (FAB) sources and are fixed to the stage 141 and head 142 via beam source support parts 122A and 122B, respectively. Here, the irradiation direction AR21 of the particle beam of particle beam source 161 along the irradiation axis J1 is inclined with respect to the perpendicular n2 of the bonding surface of the substrate W2. Similarly, the irradiation direction AR22 of the particle beam of particle beam source 162 along the irradiation axis J2 is inclined with respect to the perpendicular n1 of the bonding surface of the substrate W1. The particle beam sources 161 and 162 each include, for example, a discharge chamber 1601, an electrode 1602 placed inside the discharge chamber 1601, a beam source drive unit (not shown), and a gas supply unit 1604 that supplies argon gas into the discharge chamber 1601, as shown in Figure 2. The discharge chamber 1601 is formed from a carbon material in the shape of a long box, and its peripheral wall is provided with multiple emission ports 1601a, 1601b, and 1601c that emit a particle beam containing neutral atoms.

[0018] The multiple radiating ports 1601a, 1601b, and 1601c are arranged in a row along the longitudinal direction of the discharge chamber 1601, as shown in Figure 3, for example. Here, the orientation of the radiating ports 1601a, 1601b, and 1601c is such that it is parallel to the joint surfaces of the substrates W1 and W2 to which the particle beams emitted from the radiating ports 1601a, 1601b, and 1601c are irradiated. In other words, the multiple radiating ports 1601a, 1601b, and 1601c are arranged in a direction along the joint surfaces of the substrates W1 and W2 to which the particle beams are irradiated. Furthermore, the opening area of ​​each of the multiple radiating ports 1601a, 1601b, and 1601c is set to be larger the further away the radiating ports 1601a, 1601b, and 1601c are located in the direction of their arrangement, that is, the further away they are from the center in the longitudinal direction of the discharge chamber 1601. The opening diameter D2 of the multiple radiating ports 1601b located in region Po2 adjacent to region Po1 in the longitudinal direction of the discharge chamber 1601 is larger than the opening diameter D1 of the multiple radiating ports 1601a located in region Po1. Also, the opening diameter D3 of the multiple radiating ports 1601c located in regions Po3 at both ends in the longitudinal direction of the discharge chamber 1601 is larger than the opening diameter D2 of the multiple radiating ports 1601c located in region Po2.

[0019] The beam source drive unit includes a plasma generation unit (not shown) that generates argon gas plasma in the discharge chamber 1601, and a DC power supply (not shown) that applies a DC voltage between the electrode 1602 and the peripheral wall of the discharge chamber 1601. With argon gas plasma generated in the discharge chamber 1601, the beam source drive unit applies a DC voltage between the peripheral wall of the discharge chamber 1601 and the electrode 1602. At this time, argon ions in the plasma are attracted to the peripheral wall of the discharge chamber 1601. When argon ions heading towards the discharge port 1601a pass through the discharge port 1601a, they receive electrons from the peripheral wall of the discharge chamber 1601, which is made of carbon material, on the outer periphery of the discharge port 1601a. ​​These argon ions are then released outside the discharge chamber 1601 as electrically neutralized argon atoms. Here, the power supplied to the particle beam sources 161 and 162 is set to, for example, 1kV and 100mA. The flow rate of argon gas introduced into the discharge chambers 1601 of particle beam sources 161 and 162 is set to, for example, 50 sccm. In addition, the argon-containing plasma generated in the discharge chamber 1601 has a lower density at both ends in the longitudinal direction of the discharge chamber 1601 compared to the density in the center of the discharge chamber 1601. In response to this, the multiple radiating ports 1601a, 1601b, and 1601c of the discharge chamber 1601 are set such that the aperture diameters D2 and D3 become larger for radiating ports 1601b and 1601c that are located further away from the center (region Po1) in the longitudinal direction of the discharge chamber 1601, as described above. Therefore, the dose of the particle beam irradiated from the particle beam source 161 to regions P11 and P21 on the substrate W1 can be made uniform in the X-axis direction of regions P11 and P21. Furthermore, the density of the particle beam irradiated from the particle beam source 161 to regions P12 and P22 in the substrate W2 can be made uniform in the X-axis direction in regions P12 and P22.

[0020] Next, the operation of the bonding apparatus according to this embodiment will be described. As shown in Figure 4A, the particle beam source 161 irradiates the substrate W2 held by the head 142 with a particle beam, and the particle beam source 162 irradiates the substrate W1 held by the stage 141 with a particle beam. Here, it is assumed that the particle beam source 161 irradiates the region P12 on the -Y direction side of the substrate W2 with a particle beam, and the particle beam source 162 irradiates the region P11 on the +Y direction side of the substrate W1 with a particle beam. From this state, when the bonding apparatus moves the head 142 away from the stage 141 as shown by arrow AR11, the region on the substrate W2 irradiated with the particle beam moves from region P12 to the +Y direction as shown by arrow AR21 in Figure 5A. Also, the region on the substrate W1 irradiated with the particle beam moves from region P11 to the -Y direction as shown by arrow AR22 in Figure 5B. Then, as shown in Figure 4B, particle beam source 161 irradiates region P22 on the +Y side of substrate W2 with a particle beam, and particle beam source 162 irradiates region P21 on the -Y side of substrate W1 with a particle beam. Next, as shown by arrow AR12, when the bonding apparatus moves head 142 toward stage 141, the region on substrate W2 irradiated with the particle beam moves from region P22 toward the -Y direction, and the region on substrate W1 irradiated with the particle beam moves from region P12 toward the +Y direction. Then, the state shown in Figure 4A returns. Here, head 142 repeatedly moves up and down between a position a distance H1 away from stage 141 and a position a distance H2 away from stage 141. Distances H1 and H2 are set to be, for example, 1:3. Specifically, distance H1 is set to 50 mm and distance H2 to 150 mm. Furthermore, it is preferable to raise and lower the head 142 so that it moves from a state where the -Y side edge of the region on the substrates W1 and W2 irradiated with the particle beam coincides with the +Y side edge of the substrates W1 and W2, until that +Y side edge coincides with the -Y side edge of the substrates W1 and W2.

[0021] Furthermore, as shown in Figure 6, the bonding apparatus changes the movement speed of the head 142 according to the distance between the stage 141 and the head 142. Specifically, when the distance between the stage 141 and the head 142 is relatively long and the density of particle beams reaching the substrates W1 and W2 is low, the movement speed of the head 142 is slowed down. On the other hand, when the distance between the stage 141 and the head 142 is relatively short and the density of particle beams reaching the substrates W1 and W2 is high, the movement speed of the head 142 is increased. This makes it possible to make the amount of particle beams reaching the substrates W1 and W2 per unit time uniform, regardless of the position of the head 142 relative to the stage 141, and thus make the etching rate by the particle beam within the bonding surface of the substrates W1 and W2 uniform.

[0022] Here, we will describe the results of evaluating the uniformity of the particle beam dose to the bonding surfaces of substrates W1 and W2 during the activation process using the bonding apparatus according to this embodiment, in comparison with the bonding apparatus according to Comparative Example 1. The bonding apparatus according to Comparative Example 1 includes particle beam sources 9161 and 9162, which are formed in the shape of a long box from a carbon material, as shown in Figure 7, and have a discharge chamber 91601 with a plurality of radiating ports 91601a having the same aperture diameter D1 for radiating particle beams on its peripheral wall. The bonding apparatuses according to Comparative Examples 1 and 2 differ from the bonding apparatus according to the embodiment only in the particle beam sources 9161 and 9162; the other configurations and operations are the same as those of the bonding apparatus according to the embodiment. Therefore, the configuration of the bonding apparatus according to Comparative Example 1 will be described below using the same reference numerals as used for each component of the bonding apparatus according to the embodiment, as appropriate. However, the bonding apparatus according to Comparative Example 1 raises and lowers the head 142 at a constant moving speed. In this evaluation, substrates W1 and W2 were 4-inch diameter substrates on which an SiO2 film was formed by thermal oxidation treatment. Then, the film thickness distribution of the SiO2 film on the substrate before and after activation treatment using particle beam sources 9161 and 9162 according to the comparative example was compared with the film thickness distribution of the SiO2 film on the substrate W1 and W2 before and after activation treatment using particle beam sources 161 and 162 according to the embodiment. Here, the stage 141 and head 142 of the bonding apparatus according to Comparative Example 1 and the embodiment were held so that the SiO2 film side of the substrates W1 and W2 faced the particle beam sources 9161, 9162, 161, and 162, respectively. In addition, in the bonding apparatus according to Comparative Example 1, the head 142 was raised and lowered 10 times at a moving speed of 3.5 mm / sec. In the bonding apparatus according to the embodiment, the moving speed of the head 142 was varied between 3.5 mm / sec and 1.5 mm sec depending on the distance between the stage 141 and the head 142, and the head 142 was raised and lowered 10 times.

[0023] The film thickness distribution of the SiO2 film on substrates W1 and W2 was determined by measuring the film thickness in 13 regions P1 to P13 on substrates W1 and W2, as shown in Figure 8. The center positions of each region P1 to P13 were determined to be as shown in Table 1 below, with the P-axis and Q-axis coordinates of the centers of substrates W1 and W2 respectively set to 0 [mm].

[0024] [Table 1]

[0025] In Comparative Example 1, the SiO2 film on substrate W2 held by head 142 obtained the film thickness distributions shown in Figures 9A and 9B before and after the activation treatment, and the SiO2 film on substrate W1 held by stage 141 obtained the film thickness distributions shown in Figures 10A and 10B before and after the activation treatment. Here, the in-plane uniformity of the film thickness of the SiO2 film on substrate W2 held by head 142 after the activation treatment was 4.0%, and the in-plane uniformity of the film thickness of the SiO2 film on substrate W1 held by stage 141 after the activation treatment was 4.0%. Note that "in-plane uniformity" corresponds to the ratio of the median of the SiO2 film thickness in regions P1 to P13 of substrate W1 and W2, respectively, to the average value of the SiO2 film thickness in regions P1 to P13, respectively.

[0026] Furthermore, in this embodiment, the SiO2 film on the substrate W2 held by the head 142 obtained the film thickness distributions shown in Figures 11A and 11B before and after the activation treatment, and the SiO2 film on the substrate W1 held by the stage 141 obtained the film thickness distributions shown in Figures 12A and 12B before and after the activation treatment. Here, the in-plane uniformity of the film thickness of the SiO2 film on the substrate W2 held by the head 142 after the activation treatment was 1.2%, and the in-plane uniformity of the film thickness of the SiO2 film on the substrate W1 held by the stage 141 after the activation treatment was 1.1%. From the results of Comparative Example 1 and the embodiment, it can be seen that the in-plane uniformity of the SiO2 film on substrates W1 and W2 is improved when the movement speed of the head 142 is changed according to the distance between the stage 141 and the head 142, and when the multiple radiation ports 1601a, 1601b, and 1601c of the discharge chamber 1601 are set such that the aperture diameter is larger for radiation ports 1601b and 1601c that are located further from the center in the longitudinal direction of the discharge chamber 1601, as in the particle beam sources 161 and 162 of the embodiment. Here, the in-plane uniformity of the SiO2 film on substrates W1 and W2 depends on the uniformity of the dose amount of the particle beam irradiated onto substrates W1 and W2, and it can be seen that the particle beam sources 161 and 162 of the embodiment have improved uniformity of the dose amount of the particle beam irradiated into the plane of substrates W1 and W2 compared to the particle beam sources 9161 and 9162 of Comparative Example 1. In other words, in this embodiment, it can be seen that the uniformity of the dose amount of the particle beam irradiated into the plane of substrates W1 and W2 is improved compared to Comparative Example 1.

[0027] Incidentally, in a conventional bonding apparatus as shown in Figure 13A, the positions of the particle beam sources 161 and 162 are fixed, and the particle beam is irradiated from the outside of the substrates W1 and W2 toward the bonding surface of the substrates W1 and W2. In this configuration, the dose amount on the side of the substrates W1 and W2 closer to the particle beam sources 161 and 162 is larger than the dose amount on the side farther from the particle beam sources. As a result, the etching amount on the side of the substrates W1 and W2 closer to the particle beam sources 161 and 162 is larger than the etching amount on the side farther from the particle beam sources, resulting in a difference in etching amount at both ends of the substrates W1 and W2 in the ±Y direction. Furthermore, as shown in Figure 13B, if the conventional particle beam source 9161 has a long, box-shaped discharge chamber 91601, the plasma generated in the discharge chamber 91601 has a lower density at both ends in the longitudinal direction compared to the density in the central part in the longitudinal direction of the discharge chamber 1601. Therefore, when the aperture areas of the radiation ports 91601a arranged in a row along the longitudinal direction of the discharge chamber 91601 are equal, the dose of the particle beam emitted from the radiation ports 91601a located near both ends in the longitudinal direction of the discharge chamber 91601 becomes smaller than the dose of the particle beam emitted from the radiation ports 91601a located near the center of the discharge chamber 91601. As a result, there is a difference in the amount of etching of substrates W1 and W2 between the center in the X-axis direction and both ends in the X-axis direction. Consequently, as shown in Figure 14, uneven etching occurs in the X and Y directions of substrates W1 and W2.

[0028] In contrast, in the bonding apparatus according to this embodiment, the particle beam source 161 is fixed to the stage 141, and while radiating a particle beam from outside the area on the stage 141 where the substrate W1 is placed to an area including a part of the bonding surface of the substrate W2, the head drive unit 144 moves the head 142 in the ±Z direction. As a result, as the head 142 moves in the ±Z direction, the area on the bonding surface of the substrate W2 that is irradiated with the particle beam moves within the bonding surface of the substrate W2. Therefore, by repeatedly moving the head 142 in the ±Z direction, the particle beam can be uniformly irradiated in the Y-axis direction of the substrate W2. Furthermore, the particle beam sources 161 and 162 according to this embodiment have a plurality of radiation ports 1601a, 1601b, and 1601c arranged in a direction along the joint surface of the substrates W1 and W2 to which the particle beam is irradiated. The aperture area of ​​each of the plurality of radiation ports 1601a, 1601b, and 1601c is set to be larger the further away the radiation port (for example, 1601c) is located in the direction of the arrangement of the plurality of radiation ports 1601a, 1601b, and 1601c, i.e., the further away the radiation port is located from the center in the longitudinal direction of the discharge chamber 1601. As a result, the dose of the particle beam emitted from each of the plurality of radiation ports 1601a, 1601b, and 1601c is uniform, so that the particle beam can be uniformly irradiated in the X-axis direction of the substrates W1 and W2. Therefore, the entire joint surface of the substrates W1 and W2 can be uniformly activated.

[0029] Since the bonding apparatus according to this embodiment has a somewhat limited range in which the particle beam can be irradiated, it is particularly preferable to apply it to so-called small-diameter substrates where the substrates W1 and W2 are less than 4 inches in diameter.

[0030] Furthermore, in the bonding apparatus according to this embodiment, the particle beam source 161 is fixed to the stage 141, and while radiating a particle beam from outside the area on the stage 141 where the substrate W1 is placed to an area including a part of the bonding surface of the substrate W2, the head drive unit 144 moves the head 142 in the ±Z direction. As a result, as the head 142 moves in the ±Z direction, the area on the bonding surface of the substrate W2 that is irradiated with the particle beam moves within the bonding surface of the substrate W2. Therefore, by repeatedly moving the head 142 in the ±Z direction, the particle beam can be uniformly irradiated over the entire bonding surface of the substrate W2, and the entire bonding surface can be uniformly activated. Moreover, since a transport mechanism for supporting the particle beam source 161 and moving it in a direction horizontal to the substrate W2 is unnecessary, the overall size of the apparatus can be reduced accordingly.

[0031] Although embodiments of the present invention have been described above, the present invention is not limited to the configurations of the embodiments described above. For example, as shown in Figure 15, the particle beam sources 161 and 162 may not be fixed to the stage 141 and head 142, respectively. In Figure 15, components similar to those in the embodiments are denoted by the same reference numerals as in Figure 2. The bonding apparatus according to this modified example includes a horizontal drive unit 3163 that supports the particle beam sources 161 and 162 together and moves the particle beam sources 161 and 162 in a horizontal direction perpendicular to the opposing direction of the substrates W1 and W2. In the bonding apparatus according to this modified example, as shown in Figure 16, the particle beam sources 161 and 162 move as shown by arrow AR32 while irradiating the bonding surfaces of the substrates W1 and W2 with particle beams. The bonding apparatus according to this modified example may also include particle beam sources 2161 and 2162 having a discharge chamber 21601 as shown in Figure 17, which will be described later, instead of the particle beam sources 161 and 162.

[0032] In the bonding apparatus described in the above-mentioned embodiment, the distance between the particle beams 161 and 162 and the substrates W1 and W2 changes during irradiation of the substrates W1 and W2 with the particle beam. As a result, the dose of the particle beam irradiated onto the substrates W1 and W2 changes, and consequently, the etching rate of the substrate surfaces W1 and W2 changes. In contrast, with this configuration, the particle beam can be irradiated onto the substrates W1 and W2 while maintaining a constant distance between the particle beam sources 161 and 162 and the substrates W1 and W2. Therefore, the movement speed of the particle beams 161 and 162 can be kept constant, and the dose of the particle beam irradiated onto the substrates W1 and W2 can be made uniform.

[0033] In the embodiment, for example, as shown in Figure 17, the particle beam sources 2161 and 2162, the discharge chamber 21601 may have multiple types of radiation ports 21601a, 21601b, and 21601c with different radiation directions. Here, the orientation of each of the radiation ports 21601a, 21601b, and 21601c is such that it is parallel to the joint surface of the substrates W1 and W2 to which the particle beams emitted from the radiation ports 21601a, 21601b, and 21601c are irradiated. That is, the multiple radiation ports 21601a, 21601b, and 21601c are arranged in a direction along the joint surface of the substrates W1 and W2 to which the particle beams are irradiated. Furthermore, the aperture area of ​​each of the multiple radiating ports 21601a, 21601b, and 21601c is set such that the angle of inclination from the direction perpendicular to the longitudinal direction of the discharge chamber 21601 toward one end of the longitudinal direction is larger for radiating ports 21601a, 21601b, and 21601c that are located further away from the center in the longitudinal direction of the discharge chamber 21601. Specifically, the radiation axis J21 of the particle beams from the multiple radiating ports 21601a, which are located in the central region Po21 in the longitudinal direction of the discharge chamber 21601, is approximately parallel to the direction perpendicular to the longitudinal direction of the discharge chamber 21601. Furthermore, the radiation axes J22 of the multiple radiation ports 21601b located in region Po22 adjacent to region Po21 in the longitudinal direction of the discharge chamber 21601 are inclined in a direction perpendicular to the longitudinal direction of the discharge chamber 21601, i.e., at an angle θ21 with respect to the radiation axis J21. In addition, the radiation axes J23 of the multiple radiation ports 21601c located in regions Po23 at both ends in the longitudinal direction of the discharge chamber 21601 are inclined in a direction perpendicular to the longitudinal direction of the discharge chamber 21601, i.e., at an angle θ22 with respect to the radiation axis J21, and angle θ22 is greater than angle θ21.

[0034] In the particle beam sources 2161 and 2162 according to this modified example, the particle beam is emitted from near the center of the discharge chamber 21601 in the longitudinal direction, where the plasma density generated in the discharge chamber 21601 is relatively high, through the radiation ports 21601c located at both ends in the longitudinal direction of the discharge chamber 21601. Therefore, the difference in the dose amount of the particle beam emitted from the radiation ports 21601a, 21601b, and 21601c can be reduced. As a result, the dose amount of the particle beam reaching the substrates W2 and W1 from the particle beam sources 2161 and 2162 can be made uniform in the X-axis direction in the regions P12, P22, P11, and P21 on the substrates W2 and W1 that are irradiated with the particle beam. Consequently, the etching rates of substrates W1 and W2 can be made uniform in the Y-axis direction in the regions P11 and P21 of substrate W1 and regions P12 and P22 of substrate W2.

[0035] In this embodiment, the system may include a radiation direction changing unit (not shown) that changes the radiation direction of at least one of the particle beams from the particle beam sources 161 and 162 according to the distance between the stage 141 and the head 142.

[0036] In the embodiment described, an example was described in which two particle beam sources 161 and 162 are fixed to the stage 141 and the head 142, respectively. However, the invention is not limited to this, and for example, the bonding apparatus may have one particle beam source fixed to the stage 141, or one particle beam source fixed to the head 142.

[0037] In this embodiment, an example of raising and lowering the head 142 has been described, but it is not limited to this. For example, the stage 141 may be raised and lowered while the vertical movement of the head 142 is restricted, or both the stage 141 and the head 142 may be raised and lowered.

[0038] In the embodiments described, an example was given in which a particle beam is irradiated onto the bonding surface of substrates W1 and W2 during the activation process. However, the invention is not limited to this, and for example, an ion gun may be used to irradiate the bonding surface of substrates W1 and W2 with an ion beam. Furthermore, in each embodiment, the particle beam sources 161 and 162 may irradiate the bonding surface of substrates W1 and W2 with Si particles along with argon.

[0039] In each embodiment, examples were described in which the objects to be bonded are substrates W1 and W2, but the invention is not limited to this, and for example, the objects to be bonded may be a chip and a substrate.

[0040] This invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of the invention is indicated not by the embodiments, but by the claims. Various modifications made within the scope of the claims and the equivalent scope of the meaning of the invention are considered to be within the scope of this invention.

[0041] This application is based on Japanese Patent Application No. 2022-100457, filed on 22 June 2022. The entire specification, claims, and drawings of Japanese Patent Application No. 2022-100457 are incorporated herein by reference. [Industrial applicability]

[0042] The present invention is suitable for, for example, the manufacture of CMOS (Complementary MOS) image sensors, memory, computing elements, and MEMS (Micro Electro Mechanical Systems). [Explanation of Symbols]

[0043] 120: Chamber, 121a: Vacuum pump, 121b: Exhaust pipe, 121c: Exhaust valve, 122A, 122B: Beam source support, 141: Stage, 142: Head, 143: Stage drive unit, 144: Head drive unit, 150: Positional displacement measurement unit, 161, 162, 2161, 2162: Particle beam source, 1411, 1421: Substrate heating unit, 1441: Lifting drive unit, 1441a, 1445: Pressure sensor, 1442: XY direction drive unit, 1443: Rotation drive unit, 1444: Piezo actuator, 1601: Discharge chamber, 1601a, 21601a: Radiation port, 1602: Electrode, J1, J2: Irradiation axis, n1, n2: Perpendicular line, W1, W2: Substrate

Claims

1. A joining device for joining two objects to be joined, A first workpiece holding unit that holds one of the two workpieces to be joined, A second workpiece holding portion is positioned opposite the first workpiece holding portion and holds the other of the two workpieces to be joined, A first particle beam source is fixed to the first workpiece holding portion and emits a particle beam from outside the region in the first workpiece holding portion where one workpiece is placed to a region including a part of the joining surface of the other workpiece. The device comprises a drive unit that moves at least one of the first workpiece holding unit and the second workpiece holding unit in a first direction toward the first workpiece holding unit and the second workpiece holding unit toward each other, or in a second direction toward the first workpiece holding unit and the second workpiece holding unit toward each other. Bonding equipment.

2. The present invention further comprises a second particle beam source fixed to the second workpiece holding portion, which emits a particle beam from outside the area in the second workpiece holding portion where the other workpiece is positioned to an area in the first workpiece holding portion that includes a portion of the joining surface of the one workpiece, The joining device according to claim 1.

3. The irradiation direction of the particle beam from the first particle beam source is inclined with respect to the perpendicular to the joining surface of the other workpiece, The irradiation direction of the particle beam from the second particle beam source is inclined with respect to the perpendicular to the joint surface of the one of the objects to be joined. The joining device according to claim 2.

4. At least one of the first particle beam source and the second particle beam source has a plurality of emission ports arranged in a row for emitting a particle beam, and the orientation of the plurality of emission ports is such that it is parallel to the joining surface of one of the two workpieces to be joined, which is irradiated by the particle beam emitted from the emission ports. The joining device according to claim 2 or 3.

5. At least one of the first particle beam source and the second particle beam source is It has multiple emission ports arranged in a direction along the joint surface of the object to be joined to be irradiated with a particle beam, The opening area of ​​each of the multiple radiating ports is set to be larger the further away the radiating port is from the center in the direction in which the multiple radiating ports are arranged. The joining device according to claim 2 or 3.

6. At least one of the first particle beam source and the second particle beam source is It has multiple emission ports arranged in a direction along the joint surface of the object to be joined to be irradiated with a particle beam, The direction of emission of the particle beam from each of the plurality of emission ports is set such that the emission port located further from the center in the direction of alignment of the plurality of emission ports has a larger inclination angle from the direction perpendicular to the alignment direction toward one end of the alignment direction. The joining device according to claim 2 or 3.

7. The drive unit moves at least one of the first workpiece holding unit and the second workpiece holding unit such that the speed of movement decreases as the distance between them increases. The joining device according to any one of claims 1 to 3.

8. At least one of the two objects to be joined is a substrate that is circular in plan view with a diameter of 6 inches or less. The joining device according to any one of claims 1 to 3.

9. An activation step is performed in which, with one of the two objects to be joined being held in the first object to be joined, and the other object to be joined being held in the second object to be joined, a first particle beam source fixed to the first object to be joined irradiates a region in the second object to be joined that includes a part of the joining surface of the other object to be joined from outside the region in the first object to be joined in the first object to be joined to be held, and moves at least one of the first object to be joined and the second object to be joined in either a first direction in which the first object to be joined and the second object to be joined are moved toward each other or toward a second direction in which the first object to be joined and the second object to be joined are moved toward each other, thereby activating the joining surfaces of the two objects to be joined. A joining step is to join the two objects to be joined by bringing the joining surfaces of the two objects to be joined, whose joining surfaces have been activated, into contact with each other. Joining method.

10. In the joining process, the second particle beam source fixed to the second workpiece holder irradiates a particle beam from outside the area in the second workpiece holder where the other workpiece is placed to an area including a part of the joining surface of the first workpiece, while moving at least one of the first workpiece holder and the second workpiece holder in the first or second direction. The joining method according to claim 9.

11. At least one of the two objects to be joined is a substrate that is circular in plan view with a diameter of 6 inches or less. The joining method according to claim 9 or 10.

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