Atomic beam generator and bonding device

Abstract

This atomic beam generation device (10) comprises: a planar anode (11);a planar cathode (12) disposed facing the anode (11); a gas introduction part (15) which introduces a gas between the anode (11) and the cathode (12); and a power supply (20) which applies a high voltage between the anode (11) and the cathode (12) and generates an atomic beam from the gas. The cathode (12) comprises an emission port (16) for emitting the atomic beam from the gas.

Description

[Technical field]

[0001] The present disclosure relates to an atomic beam generating device and a bonding device. [Background technology]

[0002] A technique for bonding wafers is to remove contaminants and oxide films from the wafer surface by irradiating it with a fast atom beam (FAB) and then activate the surface to bond them at room temperature. Plasma is generated when a rare gas is introduced into an atomic beam generator and a voltage is applied between the cathode and anode to form a discharge space. Gas ions generated within the plasma are accelerated by an electric field. Among these, gas ions moving toward an irradiation port provided in a part of the housing receive electrons from the wall of the irradiation port, become neutral, and are emitted from the irradiation port as an atomic beam.

[0003] As such an atomic beam generator, for example, Patent Document 1 discloses an atomic beam generator having a cathode, which is a housing having an emission surface with an irradiation port capable of emitting atomic beams, an anode disposed inside the cathode and generating plasma between the anode and the cathode, and a first magnetic field generating unit that generates a first magnetic field and a second magnetic field generating unit that generates a second magnetic field, the first magnetic field and the second magnetic field generating unit generating a first magnetic field and a second magnetic field within the cathode parallel to the emission surface such that when viewed from the emission surface side with the first magnetic field above the second magnetic field, the magnetic field directions are leftward for the first magnetic field and rightward for the second magnetic field, and the magnetic field generating unit directs cations generated within the cathode to the emission surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 207958 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional atomic beam generators have small irradiation ports compared to the overall size of the device, so when performing surface activation processing to bond large-diameter 300mm-class wafers, which have been developed and spread in recent years, or 450mm-class wafers, which are expected to spread in the future, four or more atomic beam generators must be used per wafer. Furthermore, if these atomic beam generators were to be enlarged while maintaining the same structure, the entire bonding device would also need to be enlarged. Therefore, there was a need to develop a new atomic beam generator with a different structure from the conventional one, which would enable a larger irradiation surface.

[0006] In addition to the large area of ​​the irradiation surface, another problem with conventional atomic beam generators is the issue of fine particles being emitted from the device as the irradiation time increases. This occurs due to a sputtering phenomenon caused by the collision of gas ions inside the device with the inside of the device, which wears away the inside of the device, and the wear powder turns into fine particles and is emitted. These fine particles adhere to the joining surface of the surface activated bonding, causing bonding failure.

[0007] In the atomic beam generator of Patent Document 1, a magnetic field generating unit that guides positive ions to the radiation surface by a magnetic field reduces the collision of gas ions inside the device with the inner surface of the device, thereby reducing the emission of fine particles. However, a magnetic field parallel to the radiation surface is required, and the magnetic field generating unit for generating the magnetic field must be installed near the irradiation port. For this reason, if the irradiation port is made larger, the magnetic field decreases exponentially, and it becomes necessary to apply a high magnetic field that is difficult to achieve in order to obtain the required magnetic field.

[0008] The present disclosure has been made in view of the above problems, and has an object to provide an atomic beam generating device and a bonding device that enable an increased area of ​​the irradiation surface and reduced emission of fine particles. [Means for solving the problem]

[0009] In order to achieve the above object, an atomic beam generator according to an embodiment of the present disclosure includes a planar anode, a planar cathode arranged to face the anode, a gas inlet for introducing a gas between the anode and the cathode, and a power source for applying a high voltage between the anode and the cathode to generate an atomic beam of the gas. The cathode includes an irradiation port for irradiating the atomic beam of the gas. Also, the distance between the anode and cathode can be varied.

[0010] Moreover, the atom beam generator according to an embodiment of the present disclosure may include a magnetic field generating unit that generates a magnetic field parallel to the opposing direction of the anode and the cathode. Effect of the Invention

[0011] According to the present disclosure, it is possible to provide an atomic beam generating device and a bonding device that are capable of increasing the area of ​​the irradiation surface and reducing the emission of fine particles. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a schematic configuration and operation of an atomic beam generating apparatus according to a first embodiment of the present disclosure. [Diagram 2] 1 is a diagram showing a structure of an atomic beam generating device according to a first embodiment. [Diagram 3] FIG. 1 is a diagram showing a configuration for carrying out an oxide film removal test in Example 1. [Figure 4] FIG. 13 is a diagram showing the results of an oxide film removal test. [Diagram 5] FIG. 11 is a diagram showing details of the conditions and results of an oxide film removal test. [Figure 6] FIG. 4 is a diagram showing the results of an oxide film removal test using the atom beam generator of the first embodiment and a conventional atom beam generator. [Figure 7] FIG. 1 is a diagram showing irradiation ports of the atom beam generator of Example 1 and a conventional atom beam generator. [Figure 8] FIG. 1 is a diagram showing the irradiation ports of the atom beam generating apparatus of Example 1 and the irradiation ports of the atom beam generating apparatus of Example 2 in which the distribution of the irradiation ports is improved. [Figure 9]FIG. 4 is a diagram showing the results of an oxide film removal test using the atomic beam generator of Example 1. [Figure 10] FIG. 11 is a diagram showing the results of an oxide film removal test using the atomic beam generator of Example 2. [Figure 11] FIG. 11 is a diagram showing the results of an oxide film removal test using the atomic beam generator of Example 2. [Figure 12] FIG. 11 is a diagram showing the results of an oxide film removal test using the atomic beam generator of Example 2. [Figure 13] FIG. 13 is a diagram showing a comparison of the results of an oxide film removal test using Example 2-6 and a conventional atomic beam generator. [Figure 14] FIG. 1 is a diagram showing a calculation model used in a simulation. [Figure 15] FIG. 2 is a diagram showing the potential distribution in (a) a conventional atomic beam generator, (b) an atomic beam generator according to an embodiment having a φ80 mm electrode plate, and (c) an atomic beam generator according to an embodiment having a large diameter φ120 mm electrode plate. [Figure 16] FIG. 2 is a diagram showing the density distribution of Ar+ in (a) a conventional atomic beam generator, (b) an atomic beam generator according to an embodiment having a plate diameter of 80 mm, and (c) an atomic beam generator according to an embodiment having a large diameter plate diameter of 120 mm. [Figure 17] FIG. 11 is a diagram showing a comparison of potential distributions when the inter-electrode distance D is changed. [Figure 18] FIG. 11 is a diagram showing a comparison of potential distributions when the inter-electrode distance D is changed. [Figure 19] FIG. 13 is a diagram showing a comparison of the density distribution of Ar+ when the inter-electrode distance D is changed. [Figure 20] FIG. 11 is a diagram showing a simulation result of the potential distribution in the atomic beam generating apparatus of the second embodiment. [Figure 21] 1A and 1B are diagrams illustrating a configuration and an operation of an atomic beam generating device according to a comparative example. [Figure 22] FIG. 11 is a schematic front view of a joining device according to a second embodiment of the present disclosure. [Figure 23] FIG. 11 is a diagram showing a part of a joining device according to a second embodiment. [Figure 24]FIG. 11 is a schematic perspective view of an atomic beam generating apparatus according to a second embodiment. [Figure 25A] FIG. 11 shows a part of the bonding apparatus according to the second embodiment, illustrating a state in which the stage-head distance is at its shortest. [Figure 25B] FIG. 11 shows a part of the bonding apparatus according to the second embodiment, illustrating a state in which the stage-head distance is at its maximum. [Figure 26A] 13 is a diagram showing an atomic beam irradiation region on a stage according to the second embodiment. FIG. [Figure 26B] 11 is a diagram showing an atomic beam irradiation region in a head according to the second embodiment. FIG. [Figure 27] 5A to 5C are explanatory diagrams illustrating the operation of the joining device according to the embodiment. [Figure 28] FIG. 13 is a diagram showing a configuration of an atomic beam generating apparatus according to a modified example. [Figure 29] FIG. 13 is a diagram showing a configuration of an atomic beam generating apparatus according to a modified example. [Diagram 30] 11A and 11B are diagrams illustrating the configuration and operation of an atomic beam generating device according to a modified example. [Figure 31A] FIG. 1 is a diagram illustrating a schematic configuration of an atomic beam generating device according to a comparative example. [Figure 31B] 11A and 11B are diagrams showing simulation results of density distribution of Ar+ and incident energy distribution of Ar+ in an atomic beam generating device according to a comparative example. [Figure 32A] FIG. 13 is a diagram illustrating a schematic configuration of an atomic beam generating device according to a modified example. [Figure 32B] 13A to 13C are diagrams showing the results of simulating the density distribution of Ar+ and the incident energy distribution of Ar+ in the atomic beam generating device according to the modified example. [Figure 33A] FIG. 13 is a diagram showing a part of an atomic beam generating device according to a modified example. [Figure 33B] FIG. 13 is a diagram showing a part of an atomic beam generating device according to a modified example. [Figure 33C] FIG. 13 is a diagram showing a part of an atomic beam generating device according to a modified example. [Figure 33D] FIG. 13 is a diagram showing a part of an atomic beam generating device according to a modified example. [Diagram 34]FIG. 13 is a diagram showing a part of a joining device according to a modified example. [Diagram 35] 13A to 13C are explanatory views of the operation of the joining device according to the modified example. [Diagram 36] 13A to 13C are explanatory views of the operation of the joining device according to the modified example. [Figure 37] 13A to 13C are explanatory views of the operation of the joining device according to the modified example. [Figure 38] 13A to 13C are explanatory views of the operation of the joining device according to the modified example. [Figure 39] 13A to 13C are explanatory views of the operation of the joining device according to the modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (Embodiment 1) 1 is a schematic diagram showing the configuration and operation of an atomic beam generator according to an embodiment of the present disclosure. The atomic beam generator 10 includes an anode 11, a cathode 12, a power supply 20, an insulator 13, a housing 14, and a gas inlet 15.

[0014] The anode 11 and the cathode 12 are carbon electrodes formed into a disk shape and are arranged in parallel to face each other. A high DC voltage is applied to the anode 11 from a power source 20, and the cathode 12 is grounded. The anode 11 and the cathode 12 may be made of a metal, an alloy, or the like.

[0015] The insulator 13 is provided on the outside of the anode 11 and protects the outside of the anode 11 to which a high DC voltage is applied. The insulator 13 may be made of any material having insulating properties.

[0016] The housing 14 has a cylindrical structure made of stainless steel or the like, and contains the anode 11, the cathode 12, the insulator 13, and other components.

[0017] The gas introduction part 15 introduces a gas into the space between the anode 11 and the cathode 12. The gas introduction part 15 is provided between the anode 11 and the cathode 12 on the side surface of the housing 14. The gas is, for example, argon (Ar), N (nitrogen), O (oxygen), Xe (xenon), Ne (neon), etc. The type of gas is not particularly limited.

[0018] The power supply 20 applies a high DC voltage between the anode 11 and the cathode 12 in order to generate an atomic beam of the gas introduced through the gas inlet portion 15 .

[0019] The cathode 12 is provided with a plurality of through holes penetrating the cathode 12 as irradiation ports 16 for irradiating high-energy neutral atoms generated between the electrodes to the outside. Here, the ratio of the irradiation ports 16 to the total area of ​​the cathode 12 is 10% or more. This irradiation port ratio is preferably 30% or more. When the irradiation port ratio is 30% or more, Ar generated between the anode 11 and the cathode 12 is irradiated with the ion beam. + The ions collide with the cathode 12 at a rate of less than 30%, and the carbon atoms thus generated are redeposited on the cathode 12, thereby reducing the rate of carbon atoms redeposited on the cathode 12.

[0020] An atomic beam generator 10 is installed in a vacuum chamber of a bonding apparatus for bonding wafers, and Ar gas is introduced between the anode 11 and the cathode 12 from a gas inlet 15. When a high DC voltage is applied between the anode 11 and the cathode 12 from a power source 20 to generate a glow discharge, electrons 18 emitted into the gas convert Ar + Plasma 17 is generated. Here, the plasma is generated throughout the interior of the atomic beam generating device 10. Ar + moves at high speed between the electrodes, and when it collides with an Ar atom, it receives an electron and becomes a high-energy neutral Ar atom. +The Ar atoms receive electrons from the cathode 12 and are neutralized. Some of these neutralized high-energy Ar atoms are emitted from the irradiation port 16 to become a fast Ar atom beam 19. The fast Ar atom beam 19 is irradiated onto a wafer 30 to perform a surface activation process for bonding the wafer 30.

[0021] Conventional atomic beam generators have a structure in which Ar atoms generated between a carbon cathode provided on the inner wall of a box-shaped housing and a cylindrical anode penetrating the inside of the housing are irradiated from an irradiation port provided on the side of the housing, making it difficult to increase the area of ​​the irradiation surface. On the other hand, the atomic beam generator 10 of the present embodiment has a structure in which Ar atoms generated between a disk-shaped anode 11 and a cathode 12 provided in parallel are irradiated from an irradiation port 16 provided on the cathode 12, making it easy to increase the area of ​​the irradiation surface, and an atomic beam generator 10 having an irradiation surface with an appropriate diameter depending on the application can be realized.

[0022] 2 shows the structure of an atomic beam generator 10 according to an embodiment. The atomic beam generator 10 is configured such that an upper unit 21 including an anode 11 and a lower unit 22 including a cathode 12 can adjust their relative positions in the vertical direction using a shaft 23 and a nut 24. This allows the distance between the anode 11 and the cathode 12 (hereinafter, this inter-plate distance will be represented as D) to be variably adjusted and fixed at a desired distance. As an adjustment mechanism for changing the distance between the anode 11 and the cathode 12, any mechanism other than the shaft 23 and the nut 24 can be used.

[0023] The periphery between the upper unit 21 and the lower unit 22 is connected by an adapter 25 including a plurality of cylinders. When the distance between the upper unit 21 and the lower unit 22 is arbitrarily adjusted, in order to maintain the plasma space between the anode 11 and the cathode 12, the side portion covering the periphery between the upper unit 21 and the lower unit 22 must have a structure that can follow the change in the distance between the upper unit 21 and the lower unit 22. Therefore, the adapter 25 includes a plurality of thin cylindrical side plates. When the distance between the upper unit 21 and the lower unit 22 is changed, the plurality of cylindrical side plates are displaced from each other in the vertical direction to cover the periphery between the upper unit 21 and the lower unit 22. This allows the anode 11 and the cathode 12 to have a degree of airtightness that allows the plasma space to be maintained between them. In addition, various inter-electrode distances can be realized by combining the dimensions and numbers of the plurality of side plates. A gas supply pipe 26 for flowing gas between the anode 11 and the cathode 12 is provided in one of the plurality of side plates. By adding side panels evenly spaced in the vertical direction around this side panel, it is possible to prevent uneven distribution of gas pressure inside the chamber.

[0024] An access port 28 for observing and measuring the inside is provided on the top of the atomic beam generator 10. Normally, the access port 28 is blocked with a carbon plug and an insulator and functions as a part of the anode 11, but if necessary, the plug can be removed and the port can be used for visual observation of the inside or as an insertion port for measuring instruments.

[0025] The cathode 12 is charged with Ar during operation of the atomic beam generator 10. + It is assumed that the atomic beam generator 10 will be heated due to the sputtering caused by the electrons. For this reason, a heat sink (not shown) that utilizes circulation of cooling water and a cooling water supply pipe 29 for supplying cooling water are provided. This allows the atomic beam generator 10 to operate continuously for a long period of time. A configuration for cooling the entire atomic beam generator 10 may be provided.

[0026] [Example 1: Oxide film removal test] An oxide film removal test was carried out using the atomic beam generator 10 according to the embodiment, and the irradiation performance of the atomic beam generator 10 was investigated. A 4-inch diameter Si wafer with a 500 nm oxide film was used. The wafer and the atomic beam generator 10 were placed facing each other in a vacuum chamber, and the wafer was irradiated with a fast atomic beam from the atomic beam generator 10. An experiment was carried out in which D was fixed at 30.0 mm and the applied voltage V was changed to 350 V, 500 V, and 700 V, and an experiment was carried out in which V was fixed at 500 V and D was changed to 30.0 mm, 40.0 mm, and 50.0 mm. The film thickness was measured using an optical interference film thickness measuring device (Nanometrics Nanospec M5100).

[0027] 3 shows a configuration for carrying out the oxide film removal test of Example 1. The atomic beam generator 10 was fixed on a test stand 31 by a jig 32. The wafer 30 was placed so as to face the atomic beam generator 10. The distance from the atomic beam generator 10 to the wafer 30 was set to 113 mm.

[0028] FIG. 4 shows the results of the oxide film removal test. "◯" indicates that the oxide film measurement was successful. "△" indicates that the oxide film measurement itself was successful, but the irradiation distribution was unclear, making it impossible to measure the etching rate, which will be described later. "X" indicates that a problem occurred with the atomic beam generator 10 during the test, causing the test to be discontinued, and oxide film removal to fail.

[0029] Figure 5 shows the details of the conditions and results of the oxide film removal test. The conditions of the oxide film removal test are the applied voltage, Ar flow rate, current value, and irradiation time. In addition, the results of the oxide film removal test are the etching rate, the oxide film removal distribution image, and the distribution graph of the etching rate with the removal center as the origin.

[0030] [Example 1-1: D = 30.0 mm, V = 350 V] Although the oxide film measurement itself was successful, the irradiation distribution was unclear and it was impossible to measure the etching rate, etc., so the experimental results are not shown in Figure 5.

[0031] [Example 1-2: D = 30.0 mm, V = 500 V] The oxide film was successfully removed, and a circular irradiation distribution was confirmed near the center. An etching rate of 9.8 nm / h was recorded at the deepest point of the distribution center.

[0032] [Example 1-3: D = 30.0 mm, V = 700 V] An etching rate of 29.4 nm / h was recorded at the deepest part. This is the maximum value in Example 1. Example 1-3 has the highest voltage and the lowest Ar flow rate among the five conditions. Compared to Example 1-2, although D and current are the same conditions, the etching rate is about three times higher due to the difference in voltage and Ar flow rate. Therefore, it is considered that these conditions contribute greatly to the improvement of the etching rate.

[0033] [Example 1-4: D = 40.0 mm, V = 500 V] An etching rate of 9.1 nm / h was recorded. This is a value close to that of Example 1-2. Comparing Example 1-2 and Example 1-4, it is considered that the etching rates are close to each other because the voltage and current are the same. Here, when paying attention to the Ar flow rate of Example 1-2 and Example 1-4, it is 10 sccm higher in Example 1-2. Furthermore, the value of D is smaller in Example 1-2, and since the internal volume of the atomic beam generator 10 is smaller in Example 1-2, it is considered that the internal pressure of the atomic beam generator 10 is also higher in Example 1-2. Therefore, since the collision interval between electrons and Ar is smaller, it is considered that the electron acceleration period is shorter in Example 1-2. However, it is considered that a larger electric field is formed than in Example 1-4 because D is smaller, and a high-speed atomic beam exceeding that of Example 1-4 is generated even with a shorter electron acceleration period. For this reason, it is considered that the etching rate of Example 1-2 is higher than that of Example 1-4. Furthermore, when comparing the cross-sectional profiles of Example 1-2 and Example 1-4, the change in the cross-sectional shape of Example 1-4 is linear, whereas Example 1-2 is etched further to the periphery. This is thought to be due to the difference in potential distribution. The smaller D is, the more vertical potential gradient is seen to the periphery of the cathode 12, which is thought to increase the amount of fast atom beam irradiation from the periphery of the irradiation port 16.

[0034] [Example 1-5: D = 50.0 mm, V = 500 V] After 26 minutes of irradiation, the current became unstable and it became impossible to control it by the Ar flow rate. Furthermore, the plasma disappeared and it became impossible to re-discharge, so the test was discontinued. For this reason, the experimental results are not shown in Figure 5.

[0035] [Example 2: Improvement of the irradiation port] 6 shows the results of an oxide film removal test using the atomic beam generator 10 of the embodiment and a conventional atomic beam generator. As the results of the oxide film removal test using the atomic beam generator 10 of the embodiment, the results of Example 1-3, which had the highest etching rate among Example 1, are shown. The conventional atomic beam generator was manufactured by Oxford Instruments and is used in bonding equipment as a mass production machine.

[0036] The etching rate of the atomic beam generator 10 in Examples 1-3 was about 1 / 3 of that of the conventional type. This is believed to be due to the area and distribution of the irradiation port 16. A high etching rate leads to a reduction in the irradiation time of the high-speed atomic beam during wafer bonding, and is therefore advantageous in terms of improving productivity. In order to improve the etching rate of the atomic beam generator 10 of the embodiment, improvements to the irradiation port 16 were considered.

[0037] FIG. 7 shows the irradiation ports of the atom beam generator 10 of Example 1 and a conventional atom beam generator. In the atom beam generator 10 of Example 1, the irradiation ports 16 are provided radially. The total area of ​​the irradiation ports 16 of the atom beam generator 10 of Example 1 is about 1 / 4 of that of the conventional type. The etching rate per total area of ​​the irradiation ports 16 of the conventional type is 0.32 nm / h mm 2 whereas the atomic beam generator 10 of the first embodiment has a wavelength of 0.42 nm / h mm 2It was found that the atomic beam generator 10 of Example 1 has a higher etching rate. Therefore, it is considered that the etching rate can be improved by increasing the number of irradiation ports 16 to increase the total area. In addition, the density of the irradiation ports 16 of the atomic beam generator 10 of Example 1 decreases as the distance from the center increases. For this reason, it is considered that the etching rate decreases as the distance from the center increases. Therefore, it is considered that uniform irradiation of fast atomic beams can be achieved by distributing the irradiation ports 16 so that the density of the irradiation ports 16 is uniform.

[0038] 8 shows the irradiation ports 16 of the atom beam generator 10 of Example 1 and the irradiation ports 16 of the atom beam generator 10 of Example 2 in which the distribution of the irradiation ports 16 is improved. In the atom beam generator 10 of Example 2, the irradiation ports 16 are provided at a higher density and more uniform in the radial direction than in the atom beam generator 10 of Example 1 so that the total area of ​​the irradiation ports 16 is equivalent to that of the conventional type.

[0039] Using the atomic beam generator 10 of Example 2, an oxide film removal test was carried out in the same manner as in Example 1. The experimental conditions were as follows: Example 2-1 (D=50 mm, 500 V, 100 mA, 60 min irradiation), Example 2-2 (D=50 mm, 700 V, 100 mA, 30 min irradiation), Example 2-3 (D=40 mm, 500 V, 40 mA, 60 min irradiation), Example 2-4 (D=40 mm, 700 V, 100 mA, 30 min irradiation), Example 2-5 (D=30 mm, 700 V, 100 mA, 30 min irradiation), and Example 2-6 (D=30 mm, 1000 V, 100 mA, 30 min irradiation). In addition, the oxide film removal test was carried out again in the experiments of Example 1-1 (D=30 mm, V=350 V, 50 mA, 60 min irradiation) and Example 1-5 (D=50 mm, V=500 V, 100 mA, 60 min irradiation) where the measurement failed in Example 1, and the oxide film removal test was also carried out under the conditions of Example 1-6 (D=50 mm, V=700 V, 100 mA, 30 min irradiation).

[0040] 9 shows the results of an oxide film removal test using the atomic beam generator 10 of Example 1. Under the conditions of Example 1, etching hardly progressed, but under the conditions of Examples 1-5 and 1-6, etching rates of 10.4 nm / h and 24.2 nm / h were achieved, respectively. Although the irradiation time of Example 1-6 was shorter than that of Example 1-5, a higher etching rate was achieved, which is believed to be due to the higher voltage.

[0041] 10, 11, and 12 show the results of an oxide film removal test using the atomic beam generator 10 of Example 2. There is a tendency that the etching rate increases as D decreases and V increases, and the etching rate of Example 2-6, where D is the smallest and V is the largest, was 101 nm / h.

[0042] Figure 13 shows a comparison of the results of the oxide film removal test using Example 2-6 and the conventional atom beam generator. Although the maximum etching rate of Example 2-6 was slightly lower than that of the conventional atom beam generator, the removal volume rate of Example 2-6 was higher than that of the conventional atom beam generator. Also, Example 2-6 achieved uniform removal over a wider area than the conventional atom beam generator.

[0043] [Example 3: Consideration of increasing the area of ​​the irradiated surface] In order to study the enlargement of the irradiation surface, an operation simulation was performed for the atomic beam generator 10. The software used for the simulation was "PEGASUS" manufactured by Pegasus Software.

[0044] FIG. 14 shows the calculation model used in the simulation. The calculation region was set on a plane, but the analysis was performed in a cylindrical coordinate system with the left outer edge as the center of rotation. The right half cross-sectional shape of the atomic beam generator 10 was set to imitate a simple cylinder. Four types of models were created with D=20.5 mm, 30.0 mm, 40.0 mm, and 50.0 mm, and a gap with a width of 0.3 mm and a pitch of 4.0 mm was provided on the bottom surface of each model to serve as the irradiation port 16. In addition, the element division by the mesh was set to 0.5 mm on one side, and only the irradiation port 16 was divided to 0.3 mm on one side because the structure was fine. The initial Ar pressure inside the atomic beam generator 10 was unified at 3 Pa. Furthermore, the calculation time was set to 20 μs.

[0045] 15 and 16 show the potential distribution and Ar in (a) a conventional atomic beam generator, (b) the atomic beam generator 10 according to the embodiment with a plate diameter of 80 mm, and (c) the atomic beam generator 10 according to the embodiment with a large diameter plate diameter of 120 mm. + In the figure, the white curly brackets indicate the position and width of the irradiation port 16.

[0046] Looking at the potential distribution, (a) in the conventional atomic beam generator, a potential gradient perpendicular to the irradiation port can be seen over the entire width of the irradiation port. However, (b) in the atomic beam generator 10 of the embodiment, the direction of the potential gradient gradually changes to the side direction as it approaches the periphery of the irradiation port 16. This is thought to cause the ratio of Ar atoms entering the irradiation port 16 to decrease near the side, resulting in non-uniformity in the irradiation distribution. By increasing the aperture as in (c), a potential gradient perpendicular to the irradiation port 16 can be obtained over the entire width of the irradiation port 16, so it is thought that a uniform irradiation distribution can be achieved.

[0047] Also, Ar + Regarding the density of Ar, (a) in the conventional atomic beam generator, a high density distribution is observed over the entire width of the irradiation port. However, (b) in the atomic beam generator 10 of the embodiment, a high density distribution of Ar is observed near the center. + The distribution of Ar is biased, which is thought to result in non-uniform irradiation distribution. +It is believed that the density distribution of the laser beam spreads, thereby realizing a uniform irradiation distribution.

[0048] Figures 17 and 18 show a comparison of the potential distribution when the inter-electrode distance D is changed. Figure 17 shows the case of V=250V, and Figure 18 shows the case of V=700V. Under either condition, no abnormality occurs in the potential distribution up to 20μs, and it is shown that the device operates stably. It is also shown that the distribution of the potential gradient perpendicular to the cathode 12 becomes wider as D becomes smaller.

[0049] Figure 19 shows the relationship between the distance D between the electrodes and the Ar + Figure 19 shows a comparison of the density distributions of Ar and Ar+ for 20 μs under all conditions. + It was shown that no abnormality occurs in the density distribution of Ar and that the atomic beam generator 10 operates stably. + was shown to be more evenly distributed.

[0050] 20 shows the simulation results of the potential distribution in the atomic beam generator 10 of Example 2. The simulation was performed using a model imitating the atomic beam generator 10 of Example 2 in which the total area of ​​the irradiation port 16 was increased. The flow rate of Ar gas was increased in accordance with the increase in the total area of ​​the irradiation port 16. It was shown that no abnormality occurred in the potential distribution up to 20 μs, and stable operation was achieved.

[0051] To summarize the above results, in order to irradiate a large area with a fast atomic beam from the atomic beam generator 10 in a uniform manner, it is important to expand the atomic beam generator 10 itself in the radial direction and to find operating conditions that make the inter-plate distance D as small as possible.

[0052] 21, an atomic beam generator 9010 according to a comparative example includes an anode 9011, a box-shaped cathode 9012 made of carbon with the anode 9011 disposed inside, and a gas inlet (not shown) for introducing Ar gas into the cathode 9012. The cathode 9012 is made of carbon because carbon is a conductive material that is relatively difficult to etch and has an etching rate of about 1 / 100 of that of metal. Even if carbon atoms generated by etching the cathode 9012 pass through the irradiation port 9016 and are irradiated onto the bonding surface of the substrate to be bonded, for example, and adhere to the bonding surface, they are repelled by the Ar particles irradiated from the atomic beam generator 9010, so that the amount of carbon atoms attached to the bonding surface is below the detection limit. In the atomic beam generator 9010 according to this comparative example, a plasma PLM is generated between the two anodes 9011, and the Ar atoms contained in the Ar gas are irradiated onto the bonding surface. + The ions fly toward the inner wall of the cathode 9012 and are irradiated onto the entire inner wall of the cathode 9012. + A part of the ions passes through the irradiation port 9016 and is emitted as a particle beam to the outside of the cathode 9012. On the other hand, the Ar + Most of the ions contribute to etching the inner wall of the cathode 9012 made of carbon. However, the part of the inner wall of the cathode 9012 located on the side of the anode 9011 is in the shadow of the anode 9011, so that the Ar + Etching by ions is difficult. Therefore, carbon particles generated by etching are likely to accumulate. In particular, when the energy of the carbon particles colliding with the inner wall of the cathode 9012 is 1 eV or less, they are likely to reattach to the inner wall of the cathode 9012. Therefore, carbon lumps 9012a grow on the part of the inner wall of the cathode 9012 located to the side of the anode 9011. Then, this carbon lump 9012a is mixed with Ar +By etching with ions, relatively large carbon particles PA1 having a diameter of 0.5 μm or more fall toward the irradiation port 9016 and are emitted from the irradiation port 9016 to the outside of the cathode 9012. In addition, a thin plasma is generated around the anode 9011, so that the deposition portion (lump 9012a) on the back of the anode 9011 is also filled with Ar + Some ions fly, causing the carbon particles PA1 to fall. On the other hand, when the anode 11 and the cathode 12 are so-called parallel plates as in the present embodiment, Ar + This is different from the above because the ions do not fly as described above. In this case, if the emitted carbon particles PA1 fall onto the surface of the wafer irradiated with the atomic beam of the atomic beam generator 9010, this may cause voids of 0.5 μm or more in diameter to occur when the wafers are bonded together. In contrast, in the atomic beam generator 10 according to this embodiment, the Ar + Since the structure is such that ions are irradiated to the cathode 12 and are not easily irradiated to the anode 11 side and the housing 14, the housing 14 is not etched. Therefore, carbon lumps and the like are not easily generated in the housing 14, and the emission of carbon particles from the irradiation port 16 is suppressed. For example, even if carbon particles are etched and attached to the anode 11 or the housing 14 made of an insulator near the irradiation port 16, the carbon particles are not etched by Ar + Since the material is not etched by ions, it is unlikely to become a carbon lump and be emitted from the irradiation port.

[0053] (Embodiment 2) The bonding apparatus according to the present embodiment performs activation processing on the bonding surfaces of two wafers in a chamber in a reduced pressure atmosphere, and then brings the wafers into contact with each other and applies pressure to bond the two wafers together. The bonding apparatus includes a stage for holding one of the two wafers, a head for holding the other of the two wafers, and an atomic beam generator for irradiating an atomic beam onto an area including at least a part of the bonding surfaces of the two wafers. The wafers to be bonded include, for example, Si wafers, glass wafers such as SiO2 glass wafers, oxide wafers (e.g., silicon oxide (SiO2) wafers, alumina wafers (Al2O3) including sapphire wafers, gallium oxide (Ga2O3), etc.), nitride wafers (e.g., silicon nitride (SiN), aluminum nitride (AlN), gallium nitride (GaN)), GaAs wafers, silicon carbide (SiC) wafers, lithium tantalate (Lt:LiTaO3) wafers, lithium niobate wafers (Ln:LiNbO3), diamond wafers, etc. Alternatively, the wafers W1 and W2 may be wafers having electrodes formed of metals such as Au, Cu, Al, and Ti on their bonding surfaces. In addition, it is preferable that the wafers W1 and W2 are each circular wafers having a diameter of 6 inches or less in plan view. In the activation process, the bonding surfaces of the two wafers are activated by irradiating the bonding surfaces of the two wafers with atomic beams. The wafers may be heated before the activation process, or may be heated when the two wafers are brought into contact with each other and pressurized.

[0054] As shown in FIG. 22, the bonding apparatus according to the present embodiment includes a chamber 2120, a stage 2141, a head 2142, a stage driving unit 2143, a head driving unit 2144, wafer heating units 21411 and 21421, a positional deviation measuring unit 2150, and atomic beam generators 2161 and 2162. In the following description, the ±Z direction in FIG. 23 is appropriately defined as the up-down direction, and the XY direction is appropriately defined as the horizontal direction. The chamber 2120 is connected to a vacuum pump 2121a via an exhaust pipe 2121b and an exhaust valve 2121c. When the exhaust valve 2121c is opened and the vacuum pump 2121a is operated, the gas in the chamber 2120 is exhausted to the outside of the chamber 2120 through the exhaust pipe 2121b, and the air pressure in the chamber 2120 is reduced (decompressed). The air pressure in the chamber 2120 is 10 -5 The pressure (degree of vacuum) within the chamber 2120 can be adjusted by adjusting the amount of exhaust by varying the opening / closing amount of the exhaust valve 2121c.

[0055] The stage 2141 and the head 2142 are disposed in the chamber 2120 so as to face each other in the Z direction. The stage 2141 is a first bonded object holder that holds the wafer W1 on its upper surface, and the head 2142 is a second bonded object holder that holds the wafer W2 on its lower surface. The upper surface of the stage 2141 and the lower surface of the head 2142 may be roughened in consideration of the case where the contact surfaces of the wafers W1 and W2 with the stage 2141 and the head 2142 are mirror-finished and difficult to peel off from the stage 2141 and the head 2142. The stage 2141 and the head 2142 each have a holding mechanism (not shown) that holds the wafers W1 and W2. The holding mechanism has an electrostatic chuck, a mechanical clamp, or the like. The stage driving unit 2143 can move the stage 2141 in the XY directions and rotate it around the Z axis.

[0056] The head driving unit 2144 has an elevation driving unit 21441 that raises and lowers the head 2142 as shown by an arrow AR1, an XY direction driving unit 21442 that moves the head 2142 in the X and Y directions, and a rotation driving unit 21443 that rotates the head 2142 in a rotation direction around the Z axis. The head driving unit 2144 also has a piezo actuator 21444 that adjusts the inclination of the head 2142 with respect to the stage 2141, and a pressure sensor 21445 that measures the pressure applied to the head 2142. The XY direction driving unit 21442 and the rotation driving unit 21443 move the head 2142 relative to the stage 2141 in the X direction, the Y direction, and the rotation direction around the Z axis, thereby enabling alignment between the wafer W1 held by the stage 2141 and the wafer W2 held by the head 2142. In addition, the stage driving unit 2143 is not limited to a configuration in which it is arranged vertically below the stage 2141, and for example, a backup unit (not shown) that receives pressure vertically below the stage 2141 may be provided, and the stage driving unit 2143 may be arranged on the outer periphery of the stage 2141 to drive the stage 2141 from the side of the stage 2141.

[0057] The lifting / lowering driver 21441 moves the head 2142 vertically downward to bring the head 2142 closer to the stage 2141. The lifting / lowering driver 21441 moves the head 2142 vertically upward to move the head 2142 away from the stage 2141. When the lifting / lowering driver 21441 applies a driving force to the head 2142 in a direction toward the stage 2141 while the wafers W1 and W2 are in contact with each other, the wafer W2 is pressed against the wafer W1. The lifting / lowering driver 21441 is provided with a pressure sensor 21441a that measures the driving force applied to the head 2142 in a direction toward the stage 2141. From the measured value by the pressure sensor 21441a, the pressure acting on the bonding surfaces of the wafers W1 and W2 when the wafer W2 is pressed against the wafer W1 by the lifting / lowering driver 21441 can be detected. The pressure sensor 21441a includes, for example, a piezoelectric element.

[0058] A plurality of pairs of the piezo actuator 21444 and the pressure sensor 21445 are arranged between the head 2142 and the XY direction drive unit 21442. The pressure sensor 21445 is interposed between the upper end of the piezo actuator 21444 and the lower side of the XY direction drive unit 21442. The piezo actuators 21444 can be individually extended and contracted in the vertical direction, and by extending and contracting, the tilt of the head 2142 around the X axis and the Y axis and the vertical position of the head 2142 are finely adjusted. In addition, the pressure sensor 21445 has, for example, a piezoelectric element and measures the pressure at a plurality of points on the lower surface of the head 2142. Then, by driving each of the plurality of piezo actuators 21444 so that the pressures measured by the plurality of pressure sensors 21445 are equal, the wafers W1 and W2 can be brought into contact with each other while maintaining the lower surface of the head 2142 and the upper surface of the stage 2141 parallel to each other.

[0059] When the holding mechanism is an electrostatic chuck, for example, the wafer heating units 21411 and 21421 are first bonded object heating units having electric heaters embedded in the back side of the holding mechanism as viewed from the surface side where the wafers W1 and W2 abut on the stage 2141 and head 2142. The wafer heating units 21411 and 21421 heat the wafers W1 and W2 by transferring heat to the wafers W1 and W2 supported by the stage 2141 and head 2142. In addition, the temperature of the wafers W1 and W2 or their bonding surfaces can be adjusted by adjusting the heat generation amount of the wafer heating units 21411 and 21421. The positional deviation amount measuring unit 2150 measures the horizontal positional deviation amount of the wafer W1 with respect to the wafer W2 by recognizing the positions of alignment marks (alignment marks) provided on the wafers W1 and W2, respectively. The misalignment amount measuring unit 2150 recognizes the alignment marks of the wafers W1 and W2, for example, by using light (for example, infrared light) that passes through the wafers W1 and W2. The stage driving unit 143 moves and rotates the stage 2141 in the horizontal direction based on the misalignment amount measured by the misalignment amount measuring unit 2150, thereby performing an alignment operation between the wafers W1 and W2.

[0060] As shown in Fig. 23, the atomic beam generators 2161 and 2162 are fixed to the stage 2141 and the head 2142 via the atomic beam source supports 2122A and 2122B, respectively. Here, the irradiation direction AR21 along the irradiation axis J1 of the atomic beam of the atomic beam generator 2161 is inclined with respect to the perpendicular line n2 of the bonding surface of the wafer W2. Moreover, the irradiation direction AR22 along the irradiation axis J2 of the atomic beam of the atomic beam generator 2162 is inclined with respect to the perpendicular line n1 of the bonding surface of the wafer W1. Each of the atomic beam generators 2161 and 2162 has a housing 21601, an anode 21602 arranged in the housing 21601, a power source (not shown), and a gas supply unit 21604 that supplies argon gas into the housing 1601. 24, the housing 21601 is made of a carbon material and has a long box shape, and an irradiation port 21601a for emitting an atomic beam is provided on the peripheral wall. An anode 21602 and a cathode are disposed inside the housing 21601. The cathode 21602 is in the form of a long plate. A plurality of irradiation ports 21601a are formed in a row along the longitudinal direction of the cathode 21602.

[0061] The power supply applies a DC voltage between the anode 21602 and the cathode while generating argon gas plasma within the housing 21601. At this time, argon ions in the plasma are attracted to the peripheral wall of the housing 1601.

[0062] Next, the operation of the bonding apparatus according to the present embodiment will be described. As shown in FIG. 25A, the atomic beam generator 2161 irradiates the wafer W2 held by the head 2142 with an atomic beam, and the atomic beam generator 2162 irradiates the wafer W1 held by the stage 2141 with an atomic beam. Here, the atomic beam generator 2161 irradiates the area P12 on the -Y direction side of the wafer W2 with an atomic beam, and the atomic beam generator 2162 irradiates the area P11 on the +Y direction side of the wafer W1 with an atomic beam. From this state, when the bonding apparatus moves the head 2142 in a direction away from the stage 2141 as shown by the arrow AR11, the area on the wafer W1 irradiated with the atomic beam moves from the area P11 in the -Y direction as shown by the arrow AR31 in FIG. 26A. Also, the area on the wafer W2 irradiated with the atomic beam moves from the area P12 in the +Y direction as shown by the arrow AR32 in FIG. 26B. Then, as shown in FIG. 26B, the atomic beam generator 2161 irradiates the region P22 on the +Y direction side of the wafer W2 with the atomic beam, and the atomic beam generator 2162 irradiates the region P21 on the -Y direction side of the wafer W1 with the atomic beam. Next, when the bonding device moves the head 2142 in a direction approaching the stage 2141 as shown by the arrow AR12, the region on the wafer W1 irradiated with the atomic beam moves from the region P21 in the +Y direction, and the region on the wafer W2 irradiated with the atomic beam moves from the region P22 in the -Y direction. Then, the state shown in FIG. 25A is reached again. Here, the head 2142 repeatedly moves up and down between a position spaced a distance H1 from the stage 2141 and a position spaced a distance H2 from the stage 2141. It is preferable to raise and lower the head 2142 so that it moves from a state in which the edge on the -Y direction side of the area on the wafers W1 and W2 where the atomic beam is irradiated coincides with the edge on the +Y direction side of the wafers W1 and W2, until the edge on the +Y direction side coincides with the edge on the -Y direction side of the wafers W1 and W2.

[0063] 27, the bonding apparatus changes the moving speed of the head 2142 according to the distance between the stage 2141 and the head 2142. Specifically, when the distance between the stage 2141 and the head 2142 is relatively long and the density of the atomic beams reaching the wafers W1 and W2 is low, the moving speed of the head 2142 is slowed down. On the other hand, when the distance between the stage 2141 and the head 2142 is relatively short and the density of the atomic beams reaching the wafers W1 and W2 is high, the moving speed of the head 2142 is increased. This makes it possible to make the amount of atomic beams reaching the wafers W1 and W2 per unit time uniform regardless of the position of the head 2142 relative to the stage 2141, and therefore makes it possible to make the etching rate by the atomic beams uniform within the bonding surfaces of the wafers W1 and W2.

[0064] In the conventional bonding apparatus using an atomic beam generator, the cations generated in the plasma are irradiated onto the inner wall of the housing, which is the cathode. In this case, for example, if the inner wall of the housing is made of carbon, carbon atoms knocked out from the inner wall of the housing gather to generate carbon particles, which may adhere to the bonding surface of the wafers and cause voids to occur at the interface between the bonded wafers. In contrast, the bonding apparatus according to the present embodiment uses the atomic beam generators 2161 and 2162, and controls the cations generated in the plasma to be guided to the irradiation port 21601a, thereby preventing the cations from being irradiated onto the inner wall of the housing 21601. Therefore, the generation of carbon particles caused by the irradiation of the cations onto the inner wall of the housing 21601 made of carbon can be prevented, and therefore the adhesion of the carbon particles to the bonding surface of the wafers W1 and W2 to be bonded can be prevented, and the generation of the above-mentioned voids can be prevented.

[0065] In the atomic beam generators 2161 and 2162 according to the present embodiment, the carbon atoms emitted from the irradiation port 21601a are scattered toward the periphery of the cathode with an energy of 1 eV or more. In this case, the scattered carbon atoms are unlikely to become fine particles formed by the aggregation of carbon atoms as described above. Therefore, the adhesion of carbon fine particles to the bonding surfaces of the wafers W1 and W2 is suppressed.

[0066] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the configurations of the above-mentioned embodiments. For example, as shown in FIG. 28 and FIG. 29, the atomic beam generator 10 further includes a magnetic field generating unit for applying a magnetic field parallel to the central axis of the anode 11 and the cathode 12 in addition to the atomic beam generator 10 configuration shown in FIG. 1. In the configuration example shown in FIG. 28, an air-core coil 34 is provided as the magnetic field generating unit. In the example shown in FIG. 28, the air-core coil 34 is arranged so that its winding axis is parallel to the facing direction of the anode 11 and the cathode 12. Note that the air-core coil may be arranged so that its winding axis is perpendicular to the facing direction of the anode 11 and the cathode 12, that is, along the longitudinal direction of the housing 14, at both ends in the longitudinal direction of the housing 14. Note that the housing 14 may be, for example, in the shape of a long box. This suppresses sputtering on the side wall of the housing 14. In the configuration example shown in FIG. 29, a magnet 35 is provided as the magnetic field generating unit. Other configurations and operations are similar to those of the atomic beam generating device 10 shown in FIG. 1 or the atomic beam generating device 10 shown in FIG.

[0067] The air-core coil 34 is provided on the outer periphery of the anode 11 and the cathode 12 so as to generate a magnetic field parallel to the central axes of the anode 11 and the cathode 12. The magnet 35 is provided on the outside of the anode 11 so as to generate a magnetic field parallel to the central axes of the anode 11 and the cathode 12.

[0068] By applying a magnetic field parallel to the central axis of the anode 11 and the cathode 12 between the anode 11 and the cathode 12, Ar + The Lorentz force causes the Ar to move in a circular motion, suppressing collisions with the side surfaces and the generation of carbon particles due to sputtering. + Since the movement of the atom is not affected, the life of the side portion can be extended and the amount of carbon particles can be reduced without affecting the generation of the fast atomic beam.

[0069] 30, the atomic beam generator 7010 may include a cylindrical housing 7014, a cathode 7012 disposed at one end of the housing 7014 in the cylindrical axis direction, a cylindrical anode 7011 with a bottom disposed so as to cover the other end of the housing 7014, and a gas introduction part 7015. Here, a part of the anode 7011 is disposed so as to cover the side of a region where plasma is generated between the anode 7011 and the cathode 7012.

[0070] Here, the features of the atomic beam generator 7010 according to this modification will be described in comparison with an atomic beam generator 11010 according to a comparative example shown in Fig. 31A. The atomic beam generator 11010 comprises a cylindrical housing 11014, a cylindrical cathode 11012 with a bottom arranged so as to cover one end side in the cylindrical axis direction of the housing 11014, and an anode 11011 arranged so as to cover the other end side of the housing 11014. Regarding this atomic beam generator 11010, the voltage applied between the anode 11011 and the cathode 11012 is 1 kV, the pressure of the gas inside the atomic beam generator 11010 is 5 Pa, and the Ar + Ion density distribution, Ar irradiated to the inner wall + The result of calculating the ion incident energy by simulation is shown in FIG. 31B. As shown in FIG. 31B, the Ar + The ion density was particularly high near the center of the anode 11011. In addition, the incident energy of the Ar+ ions irradiated onto the side wall of the cathode 11012 was relatively high. From this, it is believed that sputtering was relatively strong due to the Ar+ ions on the side wall of the cathode 11012, causing particles to be generated from the cathode 11012. In addition, since the Ar+ ions were mostly irradiated onto areas of the cathode 11012 other than the irradiation port 11016, it is believed that the irradiation efficiency was also low.

[0071] On the other hand, as shown in FIG. 32A, the atomic beam generator 7010 according to this modification includes a cylindrical housing 7014, a cathode 7012 disposed at one end side in the cylindrical axis direction of the housing 7014, and a cylindrical anode 7011 with a bottom disposed so as to cover the other end of the housing 7014. The voltage applied between the anode 7011 and the cathode 7012 of this atomic beam generator 7010 is 1 kV, and the pressure of the gas in the atomic beam generator 7010 is 5 Pa. The results of simulating the density distribution of Ar+ ions in the atomic beam generator 7010 and the incident energy of the Ar+ ions irradiated to the inner wall are shown in FIG. 32B. As shown in FIG. 32B, the density of the Ar+ ions in the atomic beam generator 7010 is uniformly distributed over the entire inside of the anode 7011. The incident energy of the Ar+ ions irradiated to the anode 7011 is approximately 0, and only the incident energy of the Ar+ ions irradiated to the cathode 7012 is high. From this, it is considered that there is almost no sputtering due to the Ar+ ions on the side wall of the anode 7011, and almost no particles are generated from the anode 7011. In addition, since the Ar+ ions are irradiated intensively near the irradiation port 11016 of the cathode 11012, it is considered that the irradiation efficiency is high. As a result, the Ar + This is preferable because the ion irradiation area is limited to the cathode 7012 side.

[0072] In the first embodiment, for example, as shown in FIG. 33A, the cathode 1212 may be in the form of a long plate and have one long slit-shaped irradiation port 12016 formed therein. Here, the ratio of the irradiation port 8016 to the total area of ​​the cathode 8012 is 30% or more, and preferably 50% or more. Alternatively, for example, as shown in FIG. 33B, the cathode 8012 may be in the form of a long plate and have a plurality of long slit-shaped irradiation ports 8016 formed therein. Note that the number of the irradiation ports 8016 of the cathode 8012 is not particularly limited. The irradiation ports 8016 are each formed along the longitudinal direction of the cathode 8012. Here, the ratio of the irradiation port 8016 to the total area of ​​the cathode 8012 is preferably 50% or more. In the atomic beam generator according to this modification, ions generated inside the housing pass through the irradiation port 8016 and are emitted to the outside of the housing. Therefore, for example, a wafer to be irradiated with an atomic beam is preferably a wafer that is permitted to be charged up.

[0073] Incidentally, in an atomic beam generator equipped with a cathode 131012 having a plurality of hole-shaped 13016 irradiation ports as shown in Fig. 33C, the irradiation port ratio is usually less than 10%, and can be increased to 30% by widening the area in which the irradiation ports 14016 are formed in the cathode 14012 as shown in Fig. 33D. Also, as shown in Fig. 33A, the irradiation port ratio can be increased to 30% by making the irradiation port 12016 of the cathode 12012 slit-shaped, and as shown in Fig. 33B, the irradiation port ratio can be increased to 50% by widening the area in which the irradiation ports are formed in the cathode 8012.

[0074] In the first embodiment, for example, a magnetic field generating unit that generates a magnetic field perpendicular to the opposing direction of the anode and the cathode may be provided. Here, the atomic beam generating device may include a cylindrical housing, a cathode having an irradiation port and disposed at one end of the housing in the axial direction, an anode disposed at the other end of the housing in the axial direction, and a gas introduction unit. The magnetic field generating unit generates a magnetic field perpendicular to the opposing direction of the anode and the cathode. Here, the atomic beam generating device may include a cylindrical housing having an irradiation port and disposed at one end of the housing in the axial direction, an anode disposed at the other end of the housing in the axial direction, and a gas introduction unit. +A magnetic field perpendicular to the thickness direction of the cathode as shown in FIG. 1 is generated so as to guide ions to the cathode. The magnetic field generating unit includes a pair of sub-magnetic field generating units each having a permanent magnet arranged so that a south pole and a north pole appear at both ends in a direction perpendicular to the cylindrical axis direction of the housing and along the outer wall of the housing, and two yokes extending in a C-shape from both ends of the permanent magnet in a direction perpendicular to the cylindrical axis direction of the housing and along the outer wall of the housing, with their tips facing the side wall of the housing. The sub-magnetic field generating units generate magnetic fields in mutually opposite directions. The yokes are formed of, for example, ferrite. The permanent magnets can be, for example, neodymium magnets. By generating a magnetic field, Ar + The direction of flight of ions is more directed toward the irradiation port, and etching of the side wall of the housing is suppressed, and thus generation of particles can be suppressed. Here, the ends of the two yokes opposite to the permanent magnet side are arranged on the outside of the housing so as to face each other in a direction perpendicular to the cylindrical axis direction of the housing. The permanent magnet may be arranged at a position facing the side wall of the housing, or may be arranged on the back side of the housing opposite to the irradiation port side. The housing may be, for example, in the shape of a long box.

[0075] In the second embodiment, the atomic beam generators 2161 and 2162 are fixed to the stage 2141 and the head 2142, respectively. However, the present invention is not limited to this. For example, as shown in FIG. 34, the atomic beam generators 2161 and 2162 may not be fixed to the stage 2141 and the head 2142, respectively. In FIG. 34, the same components as those in the embodiment are denoted by the same reference numerals as those in FIG. 22. The bonding apparatus according to this modification includes a horizontal drive unit 3163 that collectively supports the atomic beam generators 2161 and 2162 and moves the atomic beam generators 2161 and 2162 in a horizontal direction perpendicular to the facing direction of the wafers W1 and W2. In the bonding apparatus according to this modification, as shown in FIG. 35, the atomic beam generators 2161 and 2162 move as indicated by the arrow AR32 while irradiating the bonding surfaces of the wafers W1 and W2 with atomic beams.

[0076] In the bonding apparatus described in the second embodiment, the distance between the atomic beam generators 2161, 2162 and the wafers W1, W2 changes during irradiation of the wafers W1, W2 with atomic beams, and the dose of the atomic beams irradiated to the wafers W1, W2 changes, which changes the etching rate of the wafers W1, W2 surfaces. In contrast, according to the present configuration, the particle beam can be irradiated to the wafers W1, W2 while the distance between the atomic beam generators 2161, 2162 and the wafers W1, W2 is kept constant, so that the dose of the atomic beams irradiated to the wafers W1, W2 can be made uniform while keeping the moving speed of the atomic beam generators 2161, 2162 constant.

[0077] In the second embodiment, the distance between the stage 2141 and the head 2142 may be fixed.

[0078] In the second embodiment, an example in which two wafers W1 and W2 are irradiated with an atomic beam simultaneously has been described, but the present invention is not limited to this, and may be modified such that, for example, as shown in Fig. 36, the wafers W1 and W2 are held one by one under the stage 4140, and the wafers W1 and W2 are irradiated with an atomic beam from the atomic beam generator 2161 in sequence. Then, when the process of irradiating the wafer W1 with the atomic beam is completed, the wafer W1 may be turned upside down and held on the stage 4141, and when the process of irradiating the wafer W2 with the atomic beam is completed, the wafer W2 may be held on the head 4142 in the same position.

[0079] In the second embodiment, an example of a bonding apparatus including two atomic beam generators 2161 and 2162 has been described, but the present invention is not limited thereto. For example, as shown in Fig. 37, the bonding apparatus may include one atomic beam generator 5161 and an attitude changer (not shown) that changes the attitude of the atomic beam generator 5161 in order to change the irradiation direction of the atomic beam of the atomic beam generator 5161. The attitude changer may change the attitude of the atomic beam generator 5161 as shown by the arrow AR51, thereby irradiating the wafer W1 held by the stage 5141 with the atomic beam or irradiating the wafer W2 held by the head 5142 with the atomic beam.

[0080] 38, the bonding apparatus may include an atomic beam generator 5161, a position changer for changing the position of the atomic beam generator 5161, and a horizontal drive unit (not shown) for collectively supporting the atomic beam generator 5161 and the position changer and moving the atomic beam generator 5161 and the position changer in a horizontal direction perpendicular to the facing direction of the wafers W1 and W2. In this case, the atomic beam generator 5161 may be moved as shown by the arrow AR62 in a state where the position of the atomic beam generator 5161 is set so that its irradiation direction is toward the stage 6141 holding the wafer W1, and then the atomic beam generator 5161 may be moved as shown by the arrow AR62 in a state where the position of the atomic beam generator 5161 is set so that its irradiation direction is toward the head 6142 holding the wafer W2.

[0081] Alternatively, as shown in FIG. 39, the bonding apparatus may include an attitude changing unit that changes the attitude of the atomic beam generator 5161, and a head driving unit (not shown) that moves the head 5142 holding the wafer W2 in the vertical direction as shown by the arrow AR71.

[0082] In the embodiment, the side surface portion covering the periphery between the upper unit 21 and the lower unit 22 may be formed from an insulating material. The side surface portion may be maintained at the same potential as the anode.

[0083] In the embodiment, the housing may be a long box-like shape, and the anode and the long plate-like cathode may be disposed inside the housing. The irradiation ports may be formed in a plurality of locations along the longitudinal direction of the cathode.

[0084] In an embodiment, the magnetic field generating unit may have a first sub-magnetic field generating unit that generates a first magnetic field and a second sub-magnetic field generating unit that generates a second magnetic field, and may generate a first magnetic field and a second magnetic field within the cathode that are perpendicular to the thickness direction of the cathode so that the direction of the magnetic field when viewed from the cathode side with the first magnetic field above the second magnetic field is leftward for the first magnetic field and rightward for the second magnetic field, and may guide the generated positive ions to the irradiation port.

[0085] In the second embodiment, the atomic beam generating device may have a first atomic beam generating unit that irradiates an atomic beam to a region including at least a part of the bonding surface of one of the two objects to be bonded, and a second atomic beam generating unit that irradiates an atomic beam to a region including at least a part of the bonding surface of the other of the two objects to be bonded. The first atomic beam generating unit and the second atomic beam generating unit may each be in the shape of a long box and have a housing with an anode and a cathode disposed inside, the cathode may be in the shape of a long plate, and a plurality of irradiation ports provided on the cathode may be formed along the longitudinal direction of the cathode.

[0086] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. The above-described embodiments are for the purpose of explaining the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0087] This application is based on Japanese Patent Application No. 2022-138910 filed on September 1, 2022. The entire specification, claims and drawings of Japanese Patent Application No. 2022-138910 are incorporated herein by reference. [Industrial Applicability]

[0088] The present invention is suitable for the manufacture of, for example, CMOS (Complementary MOS) image sensors, memories, computing elements, and MEMS (Micro Electro Mechanical Systems). [Explanation of symbols]

[0089] 10,2161,2162,7010,10010: Atomic beam generator, 11,7011,10011,21602: Anode, 12,7012,8012,10012: Cathode, 13: Insulator, 14,7014,10014: Housing, 15,7015,10015: Gas introduction part, 16,7016,8016,10016, 21601a: irradiation port, 17: plasma, 18: electrons, 19: fast atomic beam, 20: power supply, 21: upper unit, 22: lower unit, 23: shaft, 24: nut, 25: adapter, 26: gas supply pipe, 28: access port, 29: cooling water supply pipe, 30, W1, W2: wafer, 31: test stand, 32: fixture, 33: exhaust port, 2 120: chamber, 2121a: vacuum pump, 2121b: exhaust pipe, 2121c: exhaust valve, 2122A, 2122B: atomic beam source support, 2141: stage, 2142: head, 2143: stage drive, 2144: head drive, 2150: position deviation measurement, 10040: magnetic field generation, 10040A, 10040B: sub-magnetic field generation, 10041: yoke, 10042: permanent magnet, 21411, 21421: wafer heating, 21441: lift drive, 21441a, 21445: pressure sensor, 21442: XY direction drive, 21443: rotation drive, 21444: piezoelectric actuator, 21601: housing, J1, J2: irradiation axis, n1, n2: perpendicular line

Claims

1. A planar anode; a planar cathode disposed opposite the anode; a gas inlet for introducing a gas between the anode and the cathode; a power source that applies a high voltage between the anode and the cathode to generate an atomic beam of the gas; the cathode has an irradiation port for irradiating the atomic beam of the gas; The distance between the anode and the cathode is variable. Atomic beam generator.

2. a side portion covering the periphery between the anode and the cathode; 2. The atomic beam generating device according to claim 1.

3. the side portion includes a plurality of side plates provided so as to overlap each other in a direction perpendicular to the anode and the cathode, When the distance between the anode and the cathode is changed, the side plates are displaced from each other in a direction perpendicular to the anode and the cathode, thereby covering the periphery between the anode and the cathode.

3. The atomic beam generating device according to claim 2.

4. The gas inlet portion is provided on one of the plurality of side plates, and the side plates are provided in a direction perpendicular to the anode and the cathode with the side plate on which the gas inlet portion is provided being the center.

4. The atomic beam generating device according to claim 3.

5. The side surface portion is formed from an insulating material.

5. The atomic beam generating device according to claim 2,

6. The side portion is maintained at the same potential as the anode.

5. The atomic beam generating device according to claim 2,

7. The ratio of the plurality of irradiation ports to the total area of ​​the cathode is 10% or more; 5. The atomic beam generating device according to claim 1.

8. The irradiation port ratio is 30% or more.

8. The atomic beam generating device according to claim 7.

9. a cooling unit for cooling heat generated when generating the gas atomic beam; 5. The atomic beam generating device according to claim 1.

10. The cooling unit is provided in the cathode.

10. The atomic beam generating device according to claim 9.

11. A magnetic field generating unit is provided which generates a magnetic field parallel to the opposing direction of the anode and the cathode.

5. The atomic beam generating device according to claim 1.

12. A magnetic field generating unit is provided which generates a magnetic field perpendicular to the opposing direction of the anode and the cathode.

5. The atomic beam generating device according to claim 1.

13. The carbon particles emitted from the irradiation port are scattered toward the periphery of the cathode with energy of 1 eV or more.

5. The atomic beam generating device according to claim 1.

14. a magnetic field generating unit that generates a magnetic field perpendicular to a direction in which the anode and the cathode face each other; the magnetic field generating unit has a first sub-magnetic field generating unit that generates a first magnetic field and a second sub-magnetic field generating unit that generates a second magnetic field, and generates the first magnetic field and the second magnetic field in the cathode so that the magnetic field directions when the first magnetic field is viewed from the cathode side with the first magnetic field above the second magnetic field are leftward in the first magnetic field and rightward in the second magnetic field, and guides the generated positive ions to the irradiation port; 5. The atomic beam generating device according to claim 1.

15. The anode generates a plasma between the anode and the cathode, a housing in which the anode is disposed; A magnetic field generating unit that generates a magnetic field in a direction in which the anode and the cathode face each other or in a direction perpendicular to the facing direction, The magnetic field generating unit has a first sub-magnetic field generating unit that generates a first magnetic field and a second sub-magnetic field generating unit that generates a second magnetic field, and generates the first magnetic field and the second magnetic field in the housing, and guides the generated positive ions to the irradiation port.

5. The atomic beam generating device according to claim 1.

16. The ratio of the at least one irradiation port to the total area of ​​the cathode is 50% or more; 5. The atomic beam generating device according to claim 1.

17. A joining apparatus for joining two objects to be joined, A first object holding part that holds one of the two objects to be bonded; a second object holding part that is disposed opposite to the first object holding part and holds the other of the two objects to be bonded; an atomic beam generating device for irradiating an atomic beam onto a region including at least a part of a bonding surface of one of the two objects to be bonded, The atomic beam generator includes: A planar anode; a planar cathode disposed opposite the anode; a gas inlet for introducing a gas between the anode and the cathode; a power source that applies a high voltage between the anode and the cathode to generate an atomic beam of the gas; the cathode is provided with an irradiation port for irradiating the atomic beam of the gas; The distance between the anode and the cathode is variable. Bonding equipment.

18. The atomic beam generator further comprises: a housing in which the anode is disposed; a magnetic field generating unit that generates a magnetic field in a direction in which the anode and the cathode face each other or in a direction perpendicular to the facing direction; The anode generates a plasma between the anode and the cathode, The magnetic field generating unit has a first sub-magnetic field generating unit that generates a first magnetic field and a second sub-magnetic field generating unit that generates a second magnetic field, and generates the first magnetic field and the second magnetic field in the housing, and guides the generated positive ions to the irradiation port. The joining device according to claim 17.

19. The adhesion of carbon particles emitted from the atomic beam generator to the bonding surfaces of the two objects to be bonded is suppressed. The joining device according to claim 17 or 18.

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