Particle beam source, bonding system, and bonding method

Abstract

A particle beam source (1) comprises: a housing (14); an anode (11) which is disposed inside the housing (14); a cathode (12) which covers an opening (14a) of the housing (14), is disposed away from the anode (11), and has formed therein a radiation hole (12a) that emits a particle beam; and a gas supply source (30) which introduces a gas into the housing (14). A discharge hole (14b) for discharging a gas present inside the housing (14) to the outside of the housing (14) is formed in a portion of the peripheral wall of the housing (14) excluding the opening (14a), whereby an airflow is generated inside the housing (14), the airflow flowing from the gas supply source (30) into a position closer to the cathode (12) as compared with the discharge hole (14b) inside the housing (14) and flowing in a direction away from the cathode (12) so as to flow out from the discharge hole (14b).

Description

PARTICLE BEAM SOURCE, BONDING SYSTEM AND BONDING METHOD

[0001] The present invention relates to a particle beam source, a bonding system and a bonding method.

[0002] One technique for bonding wafers is to remove contaminants and oxide films from the wafer surface by irradiating them with fast atom beams (FAB), followed by surface activation, enabling room-temperature bonding. Plasma is generated when a rarefied gas is introduced into a particle beam source 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. Gas ions moving toward an emission hole located in a part of the housing receive electrons from the emission hole wall, become neutralized, and are then emitted from the emission hole as an atomic beam.

[0003] As such a particle beam source, for example, Patent Document 1 discloses a particle beam source including a cathode which is a housing having an emission surface with an emission hole capable of emitting an atomic beam, an anode disposed inside the cathode and generating plasma between the anode and the cathode, and a magnetic field generating unit which has a first magnetic field generating unit which generates a first magnetic field and a second magnetic field generating unit which generates a second magnetic field, the first magnetic field and the second magnetic field generating unit generating the first and second magnetic fields parallel to the emission surface in the cathode so that when viewed from the emission surface side with the first magnetic field above the second magnetic field, the magnetic fields point to the left for the first magnetic field and to the right for the second magnetic field, and guiding the positive ions generated in the cathode to the emission surface.

[0004] International Publication No. 2019 / 207958

[0005] In the particle beam source described in Patent Document 1, the internal surface of the device is worn away due to a sputtering phenomenon caused by collision of gas ions inside the device with the internal surface of the device, and the resulting wear powder turns into fine particles that may be emitted in the direction of emission of the atomic beam. As a result, the fine particles emitted from the particle beam source may adhere to the bonding surface of the substrate, which is the target of irradiation with the atomic beam emitted from the particle beam source, and may cause poor bonding of the substrate.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a particle beam source, a bonding system, and a bonding method in which the emission of foreign matter is suppressed.

[0007] In order to achieve the above object, the particle beam source of the present invention comprises: a box-shaped housing having an opening formed in a part of a peripheral wall, and having a first exhaust hole formed in a part of the peripheral wall excluding the opening, for exhausting gas present inside the housing to the outside of the housing; an anode arranged inside the housing; a cathode covering the opening and arranged spaced apart from the anode, having at least one emission hole formed therein that penetrates from a part exposed inside the housing to a part exposed outside the housing and radiates a particle beam; a gas supply source that introduces gas to a position inside the housing closer to the cathode than the first exhaust hole; and a voltage application unit that applies a voltage between the anode and the cathode, wherein an airflow is generated inside the housing, flowing from the gas supply source to a position inside the housing closer to the cathode than the first exhaust hole, flowing in a direction away from the cathode, and exiting through the first exhaust hole.

[0008] According to the present invention, an airflow is generated inside the housing, flowing from the gas supply source to a position inside the housing closer to the cathode than the first discharge hole, flowing in a direction away from the cathode, and flowing out through the first discharge hole. As a result, foreign matter, including abrasion powder from the inner wall of the housing caused by sputtering due to collisions of gas ions present inside the housing with the inner wall of the housing, is carried by the airflow to the discharge hole and discharged from the discharge hole to the outside of the housing. Therefore, foreign matter generated inside the housing is prevented from being released to the outside of the housing through the discharge hole of the cathode.

[0009] 1 is a schematic cross-sectional view of a particle beam source according to a first embodiment of the present invention; FIG. 2 is a plan view of a particle beam source according to a first embodiment of the present invention; FIG. 3 is a schematic cross-sectional view of a particle beam source according to a first comparative example; FIG. 4 is a schematic view showing Ar+ ions irradiating an inner wall of a cathode; FIG. 5 is a schematic view showing aggregates being formed on the inner wall of a cathode; FIG. 6 is a schematic view showing carbon particles peeling off; and FIG. 7 is an SEM photograph of the aggregate. FIG. 4 is an explanatory diagram of the operation of a particle beam source according to a first comparative example; FIG. 5 is an explanatory diagram of the operation of a particle beam source according to a second comparative example; FIG. 6 is an explanatory diagram of the operation of a particle beam source according to a first embodiment; FIG. 7 is a diagram showing the dependency of the number of particles on an object to be irradiated with a particle beam on the number of irradiations for the particle beam sources according to the first comparative example and the first embodiment; FIG. 8 is a schematic cross-sectional view of a particle beam source according to a second embodiment; FIG. 9 is a schematic plan view of a cathode according to the second embodiment; FIG. 10 is a schematic plan view of a cover according to the second embodiment; FIG. 11 is a schematic cross-sectional view of a particle beam source according to a third embodiment; FIG. 12 is a diagram showing the results of irradiating a silicon wafer with particle beams from the particle beam sources according to the first comparative example, the first embodiment, and the third embodiment; and FIG. 13 is a diagram showing the configuration and operation of a particle beam source according to a fourth embodiment. 10 is a diagram showing the structure of a particle beam source according to embodiment 4. FIG. 11 is a schematic cross-sectional view of a particle beam source according to embodiment 5. FIG. 12 is a diagram showing the results of simulating the potential distribution in the particle beam source according to embodiment 5 and comparative example 1. FIG. 13 is a schematic diagram showing the operation of the particle beam source according to comparative example 1. FIG. 14 is a schematic diagram showing the operation of the particle beam source according to embodiment 5. FIG. 15 is a schematic diagram of a second portion of the cathode according to example 3. FIG. 16 is a schematic diagram of a first portion of the particle beam source according to examples 3 to 8. FIG. 17 is a schematic diagram of a second portion of the cathode according to example 4. FIG. 18 is a diagram showing the results of irradiating a silicon wafer with a particle beam from a particle beam source according to comparative example 2, examples 3 and 4. FIG. 19 is a schematic diagram of a second portion of the cathode according to example 5. FIG. 19 is a schematic diagram of a second portion of the cathode according to example 6. FIG. 19 is a diagram showing the results of irradiating a silicon wafer with a particle beam from a particle beam source according to comparative example 2, examples 3, 5 and 6. FIG. 19 is a diagram showing the results of irradiating a silicon wafer with a particle beam from a particle beam source according to comparative example 2, examples 3, 7 and 8. FIG. 19 is a schematic front view of a bonding apparatus according to embodiment 6. FIG. 19 is a diagram showing a part of the bonding apparatus according to embodiment 6.FIG. 10 is a schematic perspective view of a particle beam source according to a sixth embodiment. FIG. 11 is a schematic cross-sectional view of another example of a particle beam source according to the sixth embodiment. FIG. 12 is a schematic cross-sectional view of another example of a particle beam source according to the sixth embodiment. FIG. 13 is a diagram showing a part of a bonding apparatus according to the sixth embodiment, illustrating a state in which the stage-head distance is at its shortest. FIG. 14 is a diagram showing a part of a bonding apparatus according to the sixth embodiment, illustrating a state in which the stage-head distance is at its longest. FIG. 15 is a diagram showing an irradiation area of ​​a particle beam on a stage according to the sixth embodiment. FIG. 16 is a diagram showing an irradiation area of ​​a particle beam on a head according to the sixth embodiment. FIG. 17 is a diagram explaining the operation of a bonding apparatus according to the sixth embodiment. FIG. 18 is a schematic configuration diagram of a bonding system according to the seventh embodiment. FIG. 19 is a schematic configuration diagram of an activation treatment apparatus according to the seventh embodiment. FIG. 19 is a schematic front view of a bonding apparatus according to the seventh embodiment. FIG. 19 is a diagram showing a part of a bonding apparatus according to the seventh embodiment. FIG. 19 is a schematic configuration diagram of a particle beam source according to the seventh embodiment. FIG. 19 is a schematic diagram showing an example of a state immediately after bonding of two substrates bonded to each other. FIG. 19 is a schematic diagram showing another example of a state immediately after bonding of two substrates bonded to each other. FIG. 19 is a schematic diagram showing a state of substrates immediately before bonding by the bonding system according to the seventh embodiment. FIG. 19 is an explanatory diagram of activation treatment according to the seventh embodiment. FIG. 1 is a schematic configuration diagram of a particle beam source according to a modified example. FIG. 2 is a schematic configuration diagram of a particle beam source according to a modified example. FIG. 3 is a schematic front view of a particle beam source according to a modified example. FIG. 4 is a schematic front view of a particle beam source according to a modified example. FIG. 5 is a schematic front view of a particle beam source according to a modified example. FIG. 6 is a schematic front view of a particle beam source according to a modified example. FIG. 7 is a schematic front view of a particle beam source according to a modified example. FIG. 8 is a diagram schematically showing the configuration and operation of a particle beam source according to a modified example. FIG. 9 is a diagram showing a part of a particle beam source according to a modified example. FIG. 10 is a diagram showing a part of a particle beam source according to a modified example. FIG. 11 is a diagram showing a part of a particle beam source according to a modified example. FIG. 12 is a diagram explaining the operation of a bonding apparatus according to a modified example. FIG. 13 is a diagram explaining the operation of a bonding apparatus according to a modified example. FIG. 14 is a diagram explaining the operation of a bonding apparatus according to a modified example. FIG. 15 is a diagram explaining the operation of a bonding apparatus according to a modified example.FIG. 10 is a schematic diagram of a particle beam source according to a modified example.

[0010] 1A , a particle beam source 1 according to this embodiment includes a housing 14, an anode 11, a cathode 12, a gas supply source 30, an insulating section 13, and a cover 15. The housing 14 is a long rectangular box having an opening 14a formed in a portion of its peripheral wall. The housing 14 also has an exhaust hole 14b formed in the peripheral wall except for the opening 14a, for exhausting gas present in a region S1 inside the housing 14 to the outside of the housing 14. An exhaust pipe 172 is connected to the exhaust hole 14b, for exhausting gas present in the region S1 inside the housing 14 to the outside of the housing 14. The gas present in the region S1 of the housing 14 is exhausted to the outside of the housing 14 through the exhaust pipe 172 by a vacuum pump 40. The vacuum pump 40 may include, for example, a turbomolecular pump and a rotary pump connected downstream of the turbomolecular pump.

[0011] The anode 11 is disposed in contact with the inner wall of the housing 14. The cathode 12 is disposed to cover the opening 14a of the housing 14 and to be spaced apart from the anode 11.

[0012] The cathode 12 has a plurality of emission holes 12a formed therein, which penetrate from the portion exposed inside the housing 14 to the portion exposed outside the housing 14 and emit a particle beam. The cathode 12 is made of, for example, carbon. Carbon is a conductive material that is relatively resistant to etching, and has an etching rate approximately 1 / 100 that of metal, making it a preferred material for forming the cathode 12. Alternatively, the surface of the carbon portion inside the housing 14 may be impregnated and coated with glassy carbon or its precursor resin. This makes the carbon portion even more resistant to etching. In fact, by applying this coating, the amount of carbon particles emitted from the particle beam source 1 can be reduced to approximately 1 / 10.

[0013] The insulating portion 13 is interposed between the housing 14 and the anode 11 and cathode 12 .

[0014] The gas supply source 30 introduces gas into the housing 14. Then, as shown by arrow AR11, an airflow is generated inside the housing 14 such that the gas flows from the gas supply source 30 through the multiple emission holes 12a to a position inside the housing 14 closer to the cathode 12 than the exhaust hole 14b, flows in a direction away from the cathode 12, and flows out of the exhaust hole 14b. Here, the average radiation direction of the particle beams emitted from the multiple emission holes 12a and the average flow direction of the airflow generated inside the housing 14 are opposite to each other.

[0015] The cover 15 is disposed so as to cover the cathode 12 from the outside of the housing 14. The cover 15 has a plurality of transmission holes 15a formed in portions facing the plurality of emission holes 12a of the cathode 12 in the emission direction of the particle beam emitted from the plurality of emission holes 12a. The transmission holes 15a allow the particle beam to pass from the cathode 12 side to the opposite side of the cathode 12 side. The gas supply source 30 supplies gas to a region S2 between the cathode 12 and the cover 15 through a gas supply pipe 171, as indicated by arrow AR12. Here, as shown in FIG. 1B , the gas supply pipes 171 are provided at a plurality of locations parallel to each other along the longitudinal direction of the cover 15. The gas supplied to the region S2 shown in FIG. 1B is introduced into a region S1 inside the housing 14 through the plurality of emission holes 12a. In other words, the gas supply source 30 introduces gas into the region S1 inside the housing 14 through the region S2 between the cathode 12 and the cover 15. Here, the opening area of ​​each of the plurality of transmission holes 15a is larger than the opening area of ​​the emission hole 12a that faces each of the plurality of transmission holes 15a in the emission direction of the particle beam.

[0016] Here, the characteristics of the particle beam source 1 according to this embodiment will be described in comparison with Comparative Examples 1 and 2, which will be described later. As shown in Fig. 2, the particle beam source 9001 according to Comparative Example 1 includes two cylindrical anodes 9011 and a box-shaped cathode 9012 made of carbon and having the two anodes 9011 disposed inside. In this particle beam source 9001, Ar is introduced into the cathode 9012 under high vacuum and a high DC voltage is applied to generate plasma PLM. Then, Ar in the generated plasma PLM ＋The ions are accelerated by an electric field generated inside the cathode 9012, neutralized when passing through the emission hole 9012a, and emitted outside the cathode 9012. A gas inlet hole 9012b for introducing Ar gas into the cathode 9012 is formed in the side wall of the cathode 9012 opposite to the side wall where the emission hole 9012a is formed. In the particle beam source 9001 according to Comparative Example 1, a plasma PLM is generated between the two anodes 9011, and the Ar gas contained in the Ar gas is neutralized. ＋ As shown by the arrow AR9001, the ions fly toward the inner wall of the cathode 9012 and are irradiated onto the entire inner wall of the cathode 9012. ＋ Some of the ions pass through the emission hole 9016 and are emitted as a particle beam to the outside of the cathode 9012. On the other hand, as shown in FIG. ＋ Sputtering by ions releases carbon atoms from the inner wall of the cathode 9012, which is made of carbon. The released carbon atoms are redeposited on the inner wall of the cathode 9012, as shown in FIG. 3B, to form aggregates (particles) De1 of the DLC layer. However, since the portions of the inner wall of the cathode 9012 located to the sides of the anode 9011 are in the shadow of the anode 9011, Ar ＋ Sputtering by ions is difficult. Therefore, carbon atoms generated by sputtering are likely to be deposited. In particular, when the energy of carbon particles colliding with the inner wall of the cathode 9012 is 1 eV or less, they are likely to be redeposited on the inner wall of the cathode 9012. Therefore, carbon aggregates De1 grow on the part of the inner wall of the cathode 9012 located to the side of the anode 9011. Here, since a thin plasma is generated around the anode 9011, the aggregates De1 generated on the back of the anode 9011 are also irradiated with Ar. ＋ Then, the aggregate De1 is irradiated with Ar ions. ＋ Repeated ion irradiation generates thermal stress and distortion in the aggregate De1, and voids are formed within the aggregate De1 as shown in Fig. 3(D) The formation of these voids causes particles PA1 to peel off from the surface of the aggregate De1 as shown in Fig. 3(C) .

[0017] In the particle beam source 9001 according to Comparative Example 1, Ar is emitted from the plurality of emission holes 12a indicated by arrows AR101 in FIG. ＋ The average radiation direction of the particle beam including ions and the average flow direction of the air current generated in the cathode 9012 indicated by the arrow AR102 are substantially the same direction. ＋ When sputtered with ions, relatively large carbon particles PA1 having a diameter of 0.5 μm or more are generated, and these particles PA1 are carried by the air current inside the cathode 9012, flow into the emission hole 9012a of the cathode 9012, and are emitted from the emission hole 9012a to the outside of the cathode 9012. In this case, if the carbon particles PA1 emitted from the emission hole 9012a fall onto the surface of the wafer W1 that is to be irradiated with a particle beam from the particle beam source 9011, this may cause voids having a diameter of 0.5 μm or more to be generated when the wafers W1 are bonded together.

[0018] 5A , in the particle beam source 9101 according to Comparative Example 2, a cover 15 having transmission holes 15a formed therein is disposed opposite the emission holes 9012a of the cathode 9012. Gas present in the cathode 9012 is exhausted to the outside of the cathode 9012 through an exhaust pipe 172 connected to an exhaust hole 9012b. A gas supply source (not shown) supplies Ar gas to the region between the cathode 9012 and the cover 15 through a gas supply pipe 171, as indicated by arrow AR12. The gas supplied to the region between the cathode 9012 and the cover 15 is then introduced into the region inside the housing 14 through the plurality of emission holes 9012a. As a result, an airflow is generated within the cathode 9012 such that gas that flows from the gas supply source through the multiple emission holes 9012a, as indicated by arrow AR12, to a position inside the cathode 9012 closer to the cathode 12 than the exhaust holes 9012b flows in a direction away from the cathode 12 and flows out of the exhaust holes 9012b. As a result, the average radiation direction of the particle beam containing Ar ions emitted from the multiple emission holes 12a, as indicated by arrow AR101 in Fig. 5A, is opposite to the average flow direction of the airflow generated within the cathode 9012, as indicated by arrow AR102. Furthermore, carbon particles PA1 generated within the cathode 9012 are exhausted to the outside of the cathode 9012 through the exhaust pipe 172, as indicated by arrow AR13.

[0019] In contrast to Comparative Examples 1 and 2, in the particle beam source 1 according to this embodiment, the anode 11 is box-shaped as shown in FIG. 5B, so that the plasma PLM is generated near the cathode 12. Therefore, compared to the configurations including the columnar anode 9011 of Comparative Examples 1 and 2, the carbon lumps De1 are less likely to be generated, and the carbon lumps De1 are less likely to be generated. ＋Carbon particles PA1 caused by sputtering by ions are also less likely to be generated. Furthermore, with the particle beam source 1 according to this embodiment, an airflow is generated inside the housing 14. The airflow flows from the gas supply source 30 to a position inside the housing 14 closer to the cathode 12 than the exhaust hole 14b, flows in a direction away from the cathode 12, and then flows out through the exhaust hole 14b. As a result, foreign matter, including abrasion powder from the inner wall of the housing 14, caused by a sputtering phenomenon due to collision of gas ions present inside the housing 14 with the inner wall of the housing 14, is carried by the airflow to the exhaust hole 14b and discharged from the exhaust hole 14b to the outside of the housing 14. Therefore, foreign matter generated inside the housing 14 is prevented from being emitted outside the housing 14 through the emission hole 12a of the cathode 12. This reduces the amount of carbon particles PA1 that fall onto the surface of the wafer W1 that is the target of particle beam irradiation by the particle beam source 1, thereby suppressing the generation of voids when the wafers W1 are bonded together.

[0020] 6 shows the results of counting the number of particles PA1 present on the wafer W1 when the wafer W1 is irradiated with a particle beam multiple times using the particle beam source 9001 according to Comparative Example 1 and the particle beam source 1 according to this embodiment. As shown in Fig. 6, when the particle beam source 9001 according to Comparative Example 1 was used, a tendency for the number of particles PA1 to increase as the number of times the wafer W1 is irradiated with the particle beam increases. In contrast, when the particle beam source 1 according to this embodiment was used, the result was that the number of particles PA1 hardly changed even when the number of times the wafer W1 is irradiated with the particle beam increases.

[0021] Furthermore, in the particle beam source 9001 according to Comparative Example 1, as described above, a plasma PLM is generated between the two anodes 9011, and Ar ions contained in the Ar gas fly toward the inner wall of the cathode 9012 as indicated by the arrows AR9001 and irradiate the entire inner wall of the cathode 9012. Here, six surfaces of the inner wall of the cathode 9012 face the anode 9011. In contrast, in the particle beam source 1 according to the present embodiment, the cathode 12 is provided only on one surface covering the opening 14a of the housing 14. Therefore, the area of ​​the portion of the cathode 12 irradiated with Ar ions is smaller than that of Comparative Example 1. This reduces the amount of carbon atoms generated by sputtering of the cathode 12 by Ar ions. Furthermore, impregnating and coating the surface of the cathode 12 with the aforementioned glassy carbon or its precursor resin is preferable because it further reduces the amount of carbon atoms generated by sputtering of the cathode 12 by Ar ions.

[0022] 7 , in a particle beam source 2001 according to this embodiment, a gas inlet hole 2012b is formed in the cathode 2012, which penetrates from a portion exposed inside the housing 14 to a portion exposed outside the housing 14 and is used to introduce gas from the outside of the housing 14 to the inside of the housing 14. The particle beam source 2001 also includes a cover 2015 attached to the housing 14 so as to cover the gas inlet hole 2012b of the cathode 2012. The cover 2015 is in contact with the cathode 2015 via an O-ring 2016.

[0023] As shown in Figure 8A, the cathode 2012 is in the form of a long rectangular plate, and multiple gas introduction holes 2012b are formed in a row along the p-axis direction on both sides in the q-axis direction of the area where multiple emission holes 12a are formed.

[0024] 8B , the cover 2015 is a long, flat, rectangular box-like structure with one side open in the thickness direction, and has a window 2015d formed in the bottom wall that is rectangular in plan view. The cover 2015 also has an annular rib 2015a that protrudes from the outer periphery of the window 2015d in the bottom wall in the same direction as the protrusion of the side wall 2015c, and a groove 2015b formed in the outer periphery of the rib 2015a in the bottom wall.

[0025] In the particle beam source 2001 according to this embodiment, the gas supply source 30 supplies gas to the region S2 inside the groove 2015b of the cover 2015. Then, the gas supplied to the region S2 inside the groove 2015b of the cover 2015 flows through the gas inlet hole 2012b of the cathode 2012 into a position inside the housing 14 closer to the cathode 12 than the outlet hole 14b.

[0026] (Embodiment 3) As shown in Figure 9, in a particle beam source 3001 according to this embodiment, a gas inlet hole 3014c is formed in a housing 3014, and a gas inlet hole 3013c communicating with the gas inlet hole 3014c is formed in a portion of an insulating part 3013 between an anode 3011 and a cathode 12.

[0027] In the particle beam source 3001 according to this embodiment, the gas supply source 30 introduces gas through the gas inlet 3014c of the housing 3014 to a position inside the housing 14 closer to the cathode 12 than the exhaust hole 14b.

[0028] Here, the results of measuring the particle beam irradiation characteristics of the particle beam source 3001 according to this embodiment and the particle beam source 1 according to embodiment 1 will be described. Here, the particle beam source according to Example 1 of embodiment 1, the particle beam source according to Example 2 of embodiment 3, and the particle beam source according to Comparative Example 1 were used to compare the distribution of oxide film etching amounts when a 4-inch silicon wafer with an oxide film was irradiated with a particle beam for one hour. The irradiation conditions for Comparative Example 1 were an acceleration voltage of 1.0 kV, a cathode current of 100 mA, and an Ar flow rate of 55 sccm. The irradiation conditions for Example 1 were an acceleration voltage of 1.0 kV, a current of 100 mA, and an Ar flow rate of 7 sccm. The irradiation conditions for Example 2 were an acceleration voltage of 1.0 kV, a cathode current of 100 mA, and an Ar flow rate of 5 sccm. As shown in FIG. 10 , Examples 1 and 2 exhibited better oxide film surface flatness than Comparative Example 1. This demonstrates that the configurations of Examples 1 and 2 can irradiate a silicon wafer with a particle beam more uniformly than the configuration of Comparative Example 1.

[0029] (Embodiment 4) FIG. 11 schematically illustrates the configuration and operation of a particle beam source according to this embodiment. The particle beam source 4001 includes an anode 11, a cathode 12, a voltage application unit 20, an insulating unit 13, a housing 4014, and a gas introduction unit 4015. The anode 11 and the cathode 12 are disk-shaped carbon electrodes arranged parallel to each other and facing each other. A high DC voltage is applied to the anode 11 from the voltage application unit 20, and the cathode 12 is grounded. That is, the anode 11 and the cathode 12 are each disk-shaped and arranged facing each other in the thickness direction. The anode 11 and the cathode 12 may be made of a metal, an alloy, or the like. The insulating unit 13 is provided on the outside of the anode 11 and protects the outside of the anode 11 to which the high DC voltage is applied. The insulating unit 13 may be made of any insulating material. The housing 4014 has a cylindrical structure made of stainless steel or the like, and houses components such as the anode 11, the cathode 12, and the insulating portion 13.

[0030] The gas introduction unit 4015 introduces a gas into the space between the anode 11 and the cathode 12. The gas introduction unit 4015 is provided on the side of the housing 4014 between the anode 11 and the cathode 12. The gas is, for example, argon (Ar), N (nitrogen), O (oxygen), Xe (xenon), Ne (neon), etc. The type of gas is not particularly limited. The voltage application unit 20 applies a high DC voltage between the anode 11 and the cathode 12 to generate a particle beam of the gas introduced by the gas introduction unit 4015.

[0031] The cathode 12 is provided with a plurality of through-holes 16 penetrating the cathode 12 for irradiating high-energy neutral atoms generated between the electrodes to the outside. Here, the ratio of the number of radiation holes 16 to the total area of ​​the cathode 12 is 10% or more. This radiation hole ratio is preferably 30% or more. When the radiation hole ratio is 30% or more, Ar generated between the anode 11 and the cathode 12 is irradiated to the outside. ＋ 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 at which the carbon atoms are redeposited on the cathode 12.

[0032] A particle beam source 4001 is installed in a vacuum chamber of a bonding apparatus for wafer bonding, and Ar gas is introduced between the anode 11 and the cathode 12 from a gas inlet 4015. When a high DC voltage is applied between the anode 11 and the cathode 12 from a voltage application unit 20 to generate a glow discharge, electrons 18 emitted into the gas cause Ar ＋ A plasma 17 is generated. Here, the plasma is generated throughout the interior of the particle beam source 4001. 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. ＋ receive electrons from the cathode 12 and are neutralized. Some of these neutralized high-energy Ar atoms fly out of the emission hole 16 to become an Ar particle beam 19. The Ar particle beam 19 is irradiated onto the wafer W1 to perform a surface activation process for bonding the wafer W1.

[0033] Conventional particle beam sources 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 emission hole provided on the side of the housing, making it difficult to increase the area of ​​the irradiation surface.In contrast, particle beam source 4001 of this embodiment has a structure in which Ar atoms generated between disk-shaped anode 11 and cathode 12 provided in parallel are irradiated from emission hole 16 provided in cathode 12, making it easy to increase the area of ​​the irradiation surface, and particle beam source 4001 having an irradiation surface with a diameter appropriate for the application can be realized.

[0034] 12 shows the structure of a particle beam source 4001 according to an embodiment. The particle beam source 4001 is configured such that the relative positions of an upper unit 21 including an anode 11 and a lower unit 22 including a cathode 12 can be adjusted 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 referred to 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.

[0035] The periphery between the upper unit 21 and the lower unit 22 is connected by an adapter 25 including multiple cylinders. To maintain a plasma space between the anode 11 and the cathode 12 when the distance between the upper unit 21 and the lower unit 22 is adjusted as desired, the side surfaces covering the periphery between the upper unit 21 and the lower unit 22 must be structured to accommodate changes in the distance between the upper unit 21 and the lower unit 22. Therefore, the adapter 25 includes multiple thin, cylindrical side plates. When the distance between the upper unit 21 and the lower unit 22 is changed, the multiple cylindrical side plates shift relative to each other in the vertical direction to cover the periphery between the upper unit 21 and the lower unit 22. This provides sufficient airtightness to maintain a plasma space between the anode 11 and the cathode 12. Various inter-electrode distances can be achieved by combining the dimensions and number of the multiple side plates. A gas supply pipe 26 is provided in one of the multiple side plates to allow gas to flow between the anode 11 and the cathode 12. By adding side panels evenly in the vertical direction around this side panel, it is possible to prevent uneven distribution of gas pressure inside the chamber.

[0036] An access port 28 for internal observation and measurement is provided at the top of the particle beam source 4001. Normally, the access port 28 is blocked with a carbon plug and an insulator, and functions as part of the anode 11, but the plug can be removed as needed to use it for visual observation of the interior or as an insertion port for measuring equipment.

[0037] In the configuration according to Comparative Example 1, as described above, the entire inner wall of the cathode 9012 is irradiated with Ar particles. For this reason, in the configuration according to Comparative Example 1, the portion of the peripheral wall of the cathode 9012 opposite to the side of the emission hole 9012a is cooled. In contrast, in the particle beam source 4001 according to this embodiment, the anode 11 and the cathode 12 are each formed in a plate shape and are arranged opposite to each other in the thickness direction. For this reason, Ar particles in the plasma generated between the anode 11 and the cathode 12 are irradiated intensively, particularly onto the cathode 12. For this reason, the cathode 12 is cooled by the Ar particles during the operation of the particle beam source 4001. ＋It is expected that heat will be generated due to sputtering by the cathode 12. For this reason, the temperature of the cathode 12 in particular is likely to rise in the particle beam source 4001. Therefore, the particle beam source 4001 according to this embodiment is preferably provided with a cooling mechanism for cooling the cathode 12. This cooling mechanism may include, for example, a heat sink (not shown) that is in contact with at least a portion of the cathode 12 and cools the cathode 12 by circulating a coolant, a coolant flow path (not shown) provided in the heat sink through which the coolant flows, and a coolant supply pipe for supplying the coolant to the coolant flow path. This allows the particle beam source 4001 to operate continuously for a long period of time. Note that the cooling mechanism may also be one that cools the entire particle beam source 4001.

[0038] In the particle beam source 4001 according to the present embodiment, Ar generated between a disk-shaped anode 11 and a cathode 12 arranged in parallel is ＋ The cathode 12 is irradiated with ions, and the anode 11 and the housing 4014 are structured to be less susceptible to irradiation, so the housing 4014 is not etched. Therefore, carbon lumps are less likely to be generated in the housing 4014, and the emission of carbon particles from the emission holes 16 is suppressed. For example, even if carbon particles are etched and adhere to the anode 11 or the housing 4014 made of an insulator near the emission holes 16, the carbon particles are not etched by Ar. ＋ Since the carbon is not etched by ions, it is unlikely to form carbon clumps and be emitted from the emission hole.

[0039] 13 , a particle beam source 5001 according to this embodiment includes a housing 5014, an anode 5011, a cathode 5012, and a gas supply source 30. In FIG. 13 , components similar to those in the first embodiment are denoted by the same reference numerals as those in FIG. 1 . The housing 5014 is a long rectangular box with one side open along its longitudinal direction. The housing 5014 has an exhaust hole 5014 b formed in a portion of the peripheral wall excluding the open portion, for exhausting gas present in a region S5001 inside the housing 5014 to the outside of the housing 5014. An exhaust pipe 172 is connected to the exhaust hole 5014 b, for exhausting gas present in the region S5001 inside the housing 5014 to the outside of the housing 5014.

[0040] The anode 5011 has a long cylindrical shape and is disposed inside the housing 5014 so that its longitudinal direction is along the longitudinal direction of the housing 5014. The cathode 5012 has a long rectangular box shape and is disposed inside the housing 5014, with the anode 5011 disposed at a position spaced apart from the inner peripheral wall. The cathode 5012 has a first portion 5121 in its peripheral wall that is exposed to the outside of the housing 5014, and multiple emission holes 5121a that emit a particle beam are formed in the first portion 5121. The cathode 5012 is also plate-shaped, with its peripheral portion continuing to the inner wall and an opening 5122a formed in the center, and has a second portion 5122 that is disposed so as to divide the cathode 5012 into a region where the anode 5011 is disposed and a region on the first portion 5121 side. Here, the distance W51 between the first portion 5121 and the second portion 5122 is preferably 10 mm or more and 24 mm or less, and the cathode 5012 is made of, for example, carbon. A gas inlet 5012c for introducing Ar gas into the cathode 5012 is formed in a portion of the peripheral wall of the cathode 5012 facing the first portion 5121.

[0041] 14A , it was found that the potential distribution in the cathode 5012 of the particle beam source 5001 according to this embodiment extends from the anode 5011-side region in the cathode 5012 through the opening 5122 a toward the first portion 5121, as compared with the potential distribution in the cathode 9012 of the particle beam source 9001 according to the above-described comparative example 1. In the particle beam source 9001 according to comparative example 1, as shown in FIG. 14B , equipotential lines near the emission port 9012 a in the cathode 9012 extend substantially parallel to the peripheral wall of the cathode 9012. Therefore, it is considered that Ar particles in the Ar plasma generated in the cathode 9012 are accelerated in a direction perpendicular to the equipotential lines substantially parallel to the peripheral wall and are emitted with high directivity in the thickness direction of the peripheral wall. 14C , in the particle beam source 5001 according to the present embodiment, the equipotential lines near the radiation port 5121a of the first portion 5121 extend in a curved manner relative to the first portion 5121. For this reason, it is considered that the Ar particles in the Ar plasma generated in the cathode 9012 are accelerated in a direction perpendicular to the equipotential lines curved relative to the first portion 5121, and are emitted from the radiation port 5121a in a diffusive manner.

[0042] Here, the results of an experiment conducted on the particle beam irradiation characteristics of the particle beam source 5001 according to this embodiment when the shape or size of the opening 5122a of the second portion 5122 was changed will be described. Here, the particle beam sources according to Examples 3 to 8 of the fifth embodiment and the particle beam source according to Comparative Example 2 were used to compare the distribution of the etching amount of an oxide film when a 4-inch silicon wafer with an oxide film was irradiated with a particle beam for one hour. In the particle beam source according to Example 3, the shape of the opening 5122a of the second portion 5122A was square in plan view, as shown in FIG. 15A , and the length W5122A of one side was 23.3 mm. In the particle beam source according to Example 3, the distance W51 between the first portion 5121 and the second portion 5122 shown in FIG. 13 was set to 17 mm. In each of the particle beam sources according to Examples 3 to 8, the emission region A5121 in which the emission port 5121a is formed is square in plan view, as shown in FIG. 15B, and a plurality of emission ports 5121a are arranged in a lattice pattern in the emission region A5121. The length W5121 of one side of the emission region A5121 is 23.3 mm. In the particle beam source according to Example 4, the shape of the opening 5122a of the second portion 5122B is rectangular in plan view, as shown in FIG. 15C, with the length W5122B1 of the long side being 33 mm and the length W5122B2 of the short side being 16.5 mm. That is, the length W5122B1 of the long side is longer than the length W5121 of one side of the emission region A5121, and the length W5122B2 of the short side is shorter than the length W5121 of one side of the emission region A5121. In the particle beam source according to Example 4, the distance W51 between the first portion 5121 and the second portion 5122 shown in FIG. 13 was set to 17 mm. The particle beam source according to Comparative Example 2 has the same configuration as the particle beam source according to Comparative Example 1 described above. The irradiation conditions for Comparative Example 2 were an acceleration voltage of 1.0 kV, a cathode current of 100 mA, and an Ar flow rate of 50 sccm. The irradiation conditions for Example 3 were an acceleration voltage of 0.98 kV, a current of 100 mA, and an Ar flow rate of 35 sccm. The irradiation conditions for Example 4 were an acceleration voltage of 1.0 kV, a cathode current of 100 mA, and an Ar flow rate of 37 sccm.

[0043] 16, the distribution of the amount of etching of the oxide film in Examples 3 and 4 was more uniform than that in Comparative Example 2. Furthermore, the distribution of the amount of etching of the oxide film in Example 3 was more uniform than that in Example 4. This shows that the configurations of Examples 3 and 4 can irradiate the particle beam more uniformly onto the silicon wafer than the configuration of Comparative Example 2.

[0044] 17A , the shape of the opening 5122a of the second portion 5122C is rectangular in plan view, with the long side length W5122C1 being 44.6 mm and the short side length W5122C2 being 11.7 mm. That is, compared to Example 4, the long side length W5122C1 is longer than the side length W5121 of the emission region A5121, and the short side length W5122C2 is shorter than the side length W5121 of the emission region A5121. Furthermore, in the particle beam source of Example 6, the shape of the opening 5122a of the second portion 5122D is isosceles triangular in plan view, with the base-to-apex length W5122D1 being 45.0 mm and the base length W5122D2 being 24.1 mm. In the particle beam sources according to Examples 5 and 6, the distance W51 between the first portion 5121 and the second portion 5122 shown in Fig. 13 was set to 17 mm. The irradiation conditions in Example 5 were an acceleration voltage of 1.0 kV, a cathode current of 100 mA, and an Ar flow rate of 30 sccm. The irradiation conditions in Example 6 were an acceleration voltage of 1.0 kV, a current of 100 mA, and an Ar flow rate of 34 sccm.

[0045] 18, the distribution of the amount of etching of the oxide film in Examples 5 and 6 was more uniform than that in Comparative Example 2. This shows that the configurations of Examples 5 and 6 allow the particle beam to be irradiated more uniformly onto the silicon wafer than the configuration of Comparative Example 2.

[0046] As described above, as shown by the distributions of the etching amount of the oxide film in Examples 3 to 6, it was found that the distribution of the etching amount of the oxide film can be changed by changing the shape and size of the opening 5122a in the second portion 5122. In other words, it was discovered that it is possible to control the distribution of the irradiation intensity of the particle beam by changing the shape and size of the opening 5122a in the second portion 5122.

[0047] In the particle beam sources according to Examples 7 and 8, the shape of the opening 5122a of the second portion 5122A was the same as that in Example 3. In the particle beam source according to Example 7, the distance W51 between the first portion 5121 and the second portion 5122 shown in Fig. 13 was set to 10 mm. In the particle beam source according to Example 7, the distance W51 between the first portion 5121 and the second portion 5122 was set to 24 mm.

[0048] 19 , the distribution of the amount of etching of the oxide film in Example 3 was more uniform than those in Examples 7 and 8. When the distance W51 between the first portion 5121 and the second portion 5122 was less than 10 mm or more than 24 mm, the distribution of the amount of etching of the oxide film was less uniform than those in Examples 3, 7, and 8. For this reason, the distance W51 between the first portion 5121 and the second portion 5122 is preferably 10 mm or more and 24 mm or less, and in particular, setting it to 17 mm is preferable from the viewpoint of improving the uniformity of the particle beam.

[0049] Sixth Embodiment A bonding apparatus according to this embodiment performs an activation process 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. This bonding apparatus includes a stage that holds one of the two wafers, a head that is disposed opposite the stage and holds the other of the two wafers, and a particle beam source that irradiates a particle beam onto an area that includes at least a portion of the bonding surface of each of the two wafers. Examples of wafers that can be used include Si wafers, SiO ２ Glass wafers such as glass wafers, oxide wafers (e.g., silicon oxide (SiO ２) wafers, alumina wafers including sapphire wafers (Al ２ O ３ ), gallium oxide (Ga ２ O ３ ) etc.), nitride wafers (e.g., silicon nitride (SiN), aluminum nitride (AlN), gallium nitride (GaN)), GaAs wafers, silicon carbide (SiC) wafers, lithium tantalate (Lt:LiTaO ３ ) wafer, lithium niobate wafer (Ln:LiNbO ３ The bonded objects are made of a metal wafer, a diamond wafer, or the like. Alternatively, the wafer may be a wafer having a metal region formed of a metal such as Au, Cu, Al, or Ti on the bonding surface. Here, the wafer having a metal region formed thereon may be a wafer in which the irradiation surface of the wafer irradiated with the particle beam includes an insulator region formed of an insulator, and the metal region and the insulator region are flush with each other. Alternatively, the irradiation surface of the wafer irradiated with the particle beam may include a metal region and an insulator region, and the metal region protrudes compared to the insulator region. Alternatively, the irradiation surface of the wafer irradiated with the particle beam may include a metal region and an insulator region, and the metal region is recessed compared to the insulator region. Preferably, each wafer is a circular wafer with a diameter of 6 inches or less in a plan view. In the activation process, the bonding surfaces of the two wafers to be bonded are activated by irradiating the bonding surfaces of the wafers with a particle beam. The wafers may be heated before the activation process, or may be heated when the two wafers are brought into contact and pressurized.

[0050] As shown in Fig. 20 , the bonding apparatus according to this embodiment includes a chamber 2120, a stage 2141, a head 2142, a stage driver 2143, a head driver 2144, wafer heating units 21411 and 21421, a misalignment measurement unit 2150, and particle beam sources 2161 and 2162. In the following description, the ±Z direction in Fig. 20 will be referred to as the vertical direction, and the XY direction 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) inside the chamber 2120 can be adjusted by adjusting the amount of exhaust by varying the opening / closing amount of the exhaust valve 2121c.

[0051] 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 object holder that holds the wafer W1 on its upper surface, and the head 2142 is a second 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 to prevent the wafers W1 and W2 from peeling off from the stage 2141 and head 2142 if the contact surfaces of the wafers W1 and W2 with the stage 2141 and head 2142 are mirror-finished. The stage 2141 and the head 2142 each have a holding mechanism (not shown) that holds the wafers W1 and W2. The holding mechanism includes an electrostatic chuck, a mechanical clamp, or the like. The stage driver 2143 can move the stage 2141 in the X and Y directions and rotate it around the Z axis.

[0052] The head driving unit 2144 includes an elevation driving unit 21441 that raises and lowers the head 2142 as indicated by 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 rotational direction around the Z axis. The head driving unit 2144 also includes a piezo actuator 21444 that adjusts the tilt 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 rotational direction around the Z axis, thereby enabling alignment of the wafer W1 held on the stage 2141 and the wafer W2 held on the head 2142. It should be noted that the stage driving unit 2143 is not limited to a configuration in which it is arranged vertically below the stage 2141, and may be configured, for example, such that a backup unit (not shown) that receives pressure is provided vertically below the stage 2141, and the stage driving unit 2143 is arranged on the outer periphery of the stage 2141, driving the stage 2141 from the side of the stage 2141.

[0053] 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 also 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 also provided with a pressure sensor 21441a that measures the driving force acting on the head 2142 in a direction toward the stage 2141. The pressure acting on the bonding surfaces of the wafers W1 and W2 when the lifting / lowering driver 21441 presses the wafer W2 against the wafer W1 can be detected from the value measured by the pressure sensor 21441a. The pressure sensor 21441a includes, for example, a piezoelectric element.

[0054] Multiple pairs of piezo actuators 21444 and pressure sensors 21445 are arranged between the head 2142 and the XY-direction drive unit 21442. The pressure sensors 21445 are interposed between the upper ends of the piezo actuators 21444 and the lower side of the XY-direction drive unit 21442. The piezo actuators 21444 are individually expandable and contractible in the vertical direction, and by expanding 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. The pressure sensors 21445 have, for example, piezoelectric elements and measure the pressure at multiple locations on the lower surface of the head 2142. By driving each of the multiple piezo actuators 21444 so that the pressures measured by the multiple 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.

[0055] For example, when the holding mechanism is an electrostatic chuck, the wafer heating units 21411 and 21421 are first object-to-be-bonded heating units having electric heaters embedded on the back side of the holding mechanism of the stage 2141 and head 2142, as viewed from the side where the wafers W1 and W2 contact. The wafer heating units 21411 and 21421 heat the wafers W1 and W2 supported by the stage 2141 and head 2142 by transferring heat to the wafers W1 and W2. The temperatures of the wafers W1 and W2 or their bonding surfaces can be adjusted by adjusting the heat generation amounts of the wafer heating units 21411 and 21421. The positional deviation measuring unit 2150 measures the horizontal positional deviation of the wafer W1 relative to the wafer W2 by recognizing the positions of alignment marks (alignment marks) provided on each of the wafers W1 and W2. The misalignment amount measuring unit 2150 recognizes the alignment marks of the wafers W1 and W2, for example, by using light (e.g., infrared light) that passes through the wafers W1 and W2. The stage driving unit 143 performs an operation of aligning the wafers W1 and W2 relative to each other (alignment operation) by moving or rotating the stage 2141 in the horizontal direction based on the amount of misalignment measured by the misalignment amount measuring unit 2150.

[0056] 21 , the particle beam sources 2161 and 2162 are fixed to the stage 2141 and the head 2142 via particle beam source supports 2122A and 2122B, respectively. An irradiation direction AR21 along the irradiation axis J1 of the particle beam from the particle beam source 2161 is inclined with respect to a normal n2 to the bonding surface of the wafer W2. Furthermore, an irradiation direction AR22 along the irradiation axis J2 of the particle beam from the particle beam source 2162 is inclined with respect to a normal n1 to the bonding surface of the wafer W1. Each of the particle beam sources 2161 and 2162 includes a housing 21603, an anode 21602 disposed in the housing 21603, a cathode 21601 disposed opposite the anode 21602, a voltage application unit (not shown), and a gas supply unit 21604 that supplies argon gas into the cathode 21601. As shown in FIG. 22A , the cathode 21601 is formed from a carbon material in a long box shape, and has emission holes 21601 a formed in its peripheral wall for emitting a particle beam. An anode 21602 is disposed inside the cathode 21601. The anode 21602 is in the shape of a long plate. A plurality of emission holes 21601 a are formed in a row along the longitudinal direction of the cathode 21602. Note that the particle beam sources 2161 and 2162 are not limited to the configuration shown in FIG. 22A . For example, as shown in FIG. 22B , a cathode 21601A may be provided that is in the shape of a rectangular box and has emission holes 21601 a formed in each of its opposing side walls, and a cylindrical anode 21602A disposed inside the cathode 21601A. 22C , the cathode 21601A may have an exhaust hole 21601b formed in a side wall thereof where the exhaust hole 21601a is not formed, for exhausting gas from the cathode 21601A. Alternatively, as shown in FIG. 22C , the cathode 21601B may have a cylindrical insulating portion 21604, two plate-shaped cathodes 21601B each having an exhaust hole 21601a penetrating the thickness direction and disposed so as to cover both ends of the insulating portion 21604, and a plate-shaped anode 21602B disposed inside the insulating portion 21604. The insulating portion 21604 may have two exhaust holes 21604b formed in a side wall thereof for exhausting gas from the insulating portion 21604.

[0057] The voltage application unit applies a DC voltage between the anode 21602 and the cathode while generating argon gas plasma inside the housing 21601. At this time, argon ions in the plasma are attracted to the peripheral wall of the housing 1601.

[0058] Next, the operation of the bonding apparatus according to this embodiment will be described. As shown in FIG. 23A, the particle beam source 2161 irradiates the wafer W2 held by the head 2142 with a particle beam, and the particle beam source 2162 irradiates the wafer W1 held by the stage 2141 with a particle beam. Here, the particle beam source 2161 irradiates the region P12 on the −Y direction side of the wafer W2 with a particle beam, and the particle beam source 2162 irradiates the region P11 on the +Y direction side of the wafer W1 with a particle beam. From this state, when the bonding apparatus moves the head 2142 away from the stage 2141 as indicated by the arrow AR11, the region on the wafer W1 irradiated with the particle beam moves from the region P11 in the −Y direction as indicated by the arrow AR31 in FIG. 23A. Furthermore, the region on the wafer W2 irradiated with the particle beam moves from the region P12 in the +Y direction as indicated by the arrow AR32 in FIG. 24B. 24B, the particle beam source 2161 irradiates a region P22 on the +Y direction side of the wafer W2 with a particle beam, and the particle beam source 2162 irradiates a region P21 on the −Y direction side of the wafer W1 with a particle beam. Next, when the bonding apparatus moves the head 2142 toward the stage 2141 as indicated by arrow AR12, the region on the wafer W1 irradiated with the particle beam moves from the region P21 in the +Y direction, and the region on the wafer W2 irradiated with the particle beam moves from the region P22 in the −Y direction. Then, the state shown in FIG. 23A 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 that the head 2142 is raised and lowered so as to move from a state in which the edge on the -Y direction side of the area on the wafers W1 and W2 irradiated with the particle beam 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.

[0059] 25 , the bonding apparatus changes the movement speed of the head 2142 depending on 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 particle beam reaching the wafers W1 and W2 is low, the movement speed of the head 2142 is slowed. On the other hand, when the distance between the stage 2141 and the head 2142 is relatively short and the density of the particle beam reaching the wafers W1 and W2 is high, the movement speed of the head 2142 is increased. This makes it possible to make the amount of particle beam reaching the wafers W1 and W2 per unit time uniform regardless of the position of the head 2142 relative to the stage 2141, thereby making the etching rate by the particle beam within the bonding surfaces of the wafers W1 and W2 uniform.

[0060] In a conventional bonding apparatus using a particle beam source, cations generated in the plasma are irradiated onto the inner wall of the housing, which serves as 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 together, generating carbon particles that adhere to the bonding surfaces of the wafers and may cause voids at the interface between the bonded wafers. In contrast, the bonding apparatus according to the present embodiment uses particle beam sources 2161 and 2162, which controls the cations generated in the plasma to be guided to the emission hole 21601a, thereby preventing the cations from irradiating the inner wall of the housing 21601. This prevents the generation of carbon particles due to cations being irradiated onto the inner wall of the housing 21601, which is made of carbon. This prevents the carbon particles from adhering to the bonding surfaces of the wafers W1 and W2, thereby preventing the above-mentioned voids from occurring.

[0061] Furthermore, in the particle beam sources 2161 and 2162 according to this embodiment, the carbon atoms emitted from the emission holes 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.

[0062] 26 , a bonding system according to this embodiment includes an introduction port 22811, an extraction port 22812, a first transfer device 2282, a cleaning device 2204, an activation treatment device 2203, bonding devices 2201 and 2202, a second transfer device 2284, a control unit 2209, and a load lock chamber 2283. The control unit 2209 controls the first transfer device 2282, the cleaning device 2204, the activation treatment device 2203, the bonding devices 2201 and 2202, and the second transfer device 2284. The first transfer device 2282, the second transfer device 2284, and the cleaning device 2204 are provided with HEPA (High Efficiency Particulate Air) filters (not shown). This creates an atmospheric pressure environment with extremely few particles inside the first transfer device 2282, the second transfer device 2284, and the cleaning device 2204.

[0063] The first transfer device 2282 includes a transfer robot 22821 having an arm with a holder at its tip that holds a wafer. The transfer robot 22821 is movable along the alignment direction of the introduction port 22811 and the removal port 22812, and can rotate to change the orientation of the arm's tip. The second transfer device 2284 also includes a transfer robot 22841 having an arm with a holder at its tip that holds a wafer. The transfer robot 22841 can rotate to change the orientation of the arm's tip. The holder has a vacuum chuck, electrostatic chuck, or the like, and adsorbs and holds the wafer on the side opposite to the bonding surface.

[0064] The cleaning device 2204 cleans the transported wafer by discharging a liquid such as water or a cleaning solution onto the wafer. The cleaning device 2204 includes a stage (not shown) that supports the wafer, an XY-direction drive unit (not shown) that drives the stage in two directions (X and Y directions) that are perpendicular to the vertical direction and perpendicular to each other, and a cleaning head (not shown) that discharges water or cleaning solution to which ultrasonic or megasonic vibrations have been applied. The cleaning device 2204 also includes a rotation drive unit (not shown) that rotates the stage in a plane perpendicular to the vertical direction. The cleaning device 2204 then scans the stage in the X and Y directions while spraying water to which ultrasonic waves have been applied onto the wafer's bonding surface using the cleaning head, thereby cleaning the entire bonding surface of the wafer. The cleaning device 2204 then stops discharging water from the cleaning head and rotates the stage to spin-dry the wafer.

[0065] 27 , the activation treatment device 2203 includes a particle beam source 22361, a stage 22341 that suction-holds the wafers W1 and W2, a chamber 22320 inside which the particle beam source 22361 and the stage 22341 are disposed, and a gas supply source 22308 that introduces gas into the chamber 22320. The activation treatment device 2203 also includes a stage driver 22343 that moves the stage 22341 in a direction perpendicular to the thickness direction of the wafers W1 and W2 as indicated by arrow AR2201, and a particle beam source driver (not shown) that oscillates the particle beam source 22361 as indicated by arrow AR2202. The particle beam source driver may also move the particle beam source 22361 parallel to the bonding surfaces of the wafers W1 and W2 as indicated by arrow AR2203. The chamber 22320 is formed with a gas inlet hole 22320a for introducing gas into the inside of the chamber 22320 and an exhaust hole 22320b for exhausting gas present in the chamber 22320 to the outside of the chamber 22320. The gas supply source 22308 introduces N 2 into the chamber 22320 through the gas inlet hole 22320a. ２The exhaust hole 22320b is connected to a vacuum pump 2240, which exhausts gas present in the chamber 22320 to the outside of the chamber 22320 through the exhaust hole 22320b. The vacuum pump 2240 includes, for example, a turbomolecular pump and a rotary pump connected downstream of the turbomolecular pump. The gas flowing into the chamber 22320 from the gas supply source 22308 through the gas inlet hole 22320a flows out of the exhaust hole 22320b, generating an airflow in the chamber 22320 that flows from the stage 22341 toward the particle beam source 22361. That is, by generating an airflow that flows from the vicinity of the bonding surfaces of the wafers W1 and W2 placed on the stage 22341 toward the particle beam source 22361, adhesion of particles floating in the chamber 22320 to the bonding surfaces of the wafers W1 and W2 can be suppressed.

[0066] As shown in Fig. 28 , the bonding apparatus 2201 includes a chamber 2120, a stage 2141, a head 2142, a stage driver 2143, a head driver 2144, wafer heating units 21411 and 21421, a positional deviation measurement unit 2150, and particle beam sources 22161 and 22162. In Fig. 28 , the same components as those in the sixth embodiment are denoted by the same reference numerals as in Fig. 20 . As shown in Fig. 29 , the particle beam sources 22161 and 22162 are fixed to the stage 2141 and the head 2142 via particle beam source support units 22122A and 22122B, respectively. Here, the particle beam sources 22161 and 22162 are arranged such that an emission area ARA1 of the particle beam emitted from the particle beam source 22161 and an emission area ARA2 of the particle beam emitted from the particle beam source 22162 partially overlap. As in the sixth embodiment, the irradiation direction AR2221 of the particle beam from the particle beam source 22161 is inclined with respect to a perpendicular to the bonding surface of the wafer W2, and the irradiation direction AR2222 of the particle beam from the particle beam source 22162 is inclined with respect to a perpendicular to the bonding surface of the wafer W1. Furthermore, the distance L2201 between the bonding surface of the wafer W1 held by the stage 2141 and the bonding surface of the wafer W2 held by the head 2142 is shorter than the distance L2201 in the sixth embodiment. This allows the inclination angles of the irradiation directions AR2221 and AR2221 of the particle beam sources 22161 and 22162 with respect to a perpendicular to the bonding surface to be acute, thereby improving the etching performance. Furthermore, since the particle beam sources 22161 and 22162 can be arranged together on one side in the Y-axis direction, the bonding device 2201 as a whole can be made smaller.

[0067] As shown in Fig. 30 , the particle beam source 22361 of the activation treatment device 2203 and the particle beam sources 22161 and 22162 of the bonding device 2001 each include a housing 14, an anode 2211, a cathode 2212, a gas supply source 30, an insulating part 13, and a cover 15. In Fig. 30 , the same components as those in the particle beam source 1 according to the first embodiment are denoted by the same reference numerals as in Fig. 1A. Gas present in the region S1 inside the housing 14 is exhausted to the outside of the housing 14 through an exhaust pipe 172 by vacuum pumps 2240 and 2121a.

[0068] The anode 2211 is disposed in contact with the inner wall of the housing 14, and the cathode 2212 is formed from Si, covers the opening 14a of the housing 14, and is disposed at a distance from the anode 2211. The cathode 2212 is formed with a plurality of emission holes 2212a that penetrate from the portion exposed inside the housing 14 to the portion exposed outside the housing 14 and emits a particle beam. Note that the anode 2211 and the cathode 2212 may be configured such that only the portion exposed inside the housing 14 is made of Si, and the portion embedded in the inner wall of the housing 14 and not exposed inside the housing 14 is made of carbon.

[0069] The particle beams emitted from such particle beam sources 22361 , 22161 , and 22162 contain Si particles scattered from the cathode 2212 .

[0070] Here, a vacuum pump for discharging the gas present in the region S1 inside the housing 14 of the particle beam source 22361 through the exhaust pipe 172 may be provided separately from the vacuum pump 2240 for discharging the gas present in the chamber 22320 to the outside of the chamber 22320. In the case where one vacuum pump 2240 is configured to discharge the gas present in the region S1 inside the housing 14 of the particle beam source 22361 and to discharge the gas present in the chamber 22320 to the outside of the chamber 22320, there have been cases where the degree of vacuum in the chamber 22320 has dropped to about 100 Pa when a particle beam is irradiated from the particle beam source 22361. In contrast, by separately providing a vacuum pump for exhausting gas present in the region S1 inside the housing 14 of the particle beam source 22361 and a vacuum pump 2240 for exhausting gas present in the chamber 22320 to the outside of the chamber 22320, it is possible to irradiate the particle beam while maintaining a high degree of vacuum within the chamber 22320. Conventionally, in order to maintain dangling bonds generated on the bonding surfaces of the wafers W1 and W2 at a vacuum of approximately 100 Pa, the particles contained in the particle beam were limited to inert particles such as Ar particles. In contrast, in this embodiment, the high degree of vacuum in the chamber 22320 allows dangling bonds to be maintained, allowing the particle beam to be optimally activated. Furthermore, while conventional particle beam sources emit particle beams accompanied by gas molecules, the particle beam source 22361 according to this embodiment emits only a particle beam without accompanying gas molecules, which is a groundbreaking invention. Furthermore, since the particle beam source 22361 according to this embodiment does not involve gas molecules, at least a portion of the irradiation areas of the particle beam can overlap with each other. On the other hand, if gas molecules are involved, at least a portion of the irradiation areas of the particle beam cannot overlap with each other. However, in this embodiment, since no gas molecules are involved, the probability of particles colliding with each other is extremely low. Furthermore, the probability of the particle beam colliding with gas molecules remaining in the chamber 22320 is reduced, improving the etching efficiency of the surfaces of the wafers W1 and W2, and making it possible to efficiently generate dangling bonds on the bonding surfaces of the wafers W1 and W2.

[0071] In the bonding system according to this embodiment, first, the transfer robot 22821 of the first transfer device 2282 transfers the wafers W1 and W2 from the introduction port 22811 to the cleaning device 2204. The cleaning device 2204 then cleans the bonding surfaces of the loaded wafers W1 and W2. Next, the transfer robot 22821 of the first transfer device 2282 transfers the wafers W1 and W2 from the cleaning device 2204 to the load lock unit 2285. Subsequently, the transfer robot 22861 of the second transfer device 2284 transfers the wafers W1 and W2 from the load lock unit 2285 to the activation treatment device 2203. The activation treatment device 2203 then performs an activation treatment process to activate at least one of the bonding surfaces of the wafers W1 and W2. Thereafter, the transfer robot 22841 of the second transfer device 2284 transfers the wafers W1 and W2 from the activation treatment device to the bonding device 2201. The bonding apparatus 2201 then performs an activation process to activate the bonding surfaces of the wafers W1 and W2 by irradiating them with a particle beam, and then temporarily bonds the wafers W1 and W2 together. Next, the transfer robot 22841 of the second transfer apparatus 2284 transfers the wafers W1 and W2 from the bonding apparatus 2201 to the bonding apparatus 2202. The bonding apparatus 2201 then heats and pressurizes the temporarily bonded wafers W1 and W2 to finally bond the wafers W1 and W2 together. Next, the transfer robot 22841 of the second transfer apparatus 2284 transfers the bonded wafers W1 and W2 from the bonding apparatus 2202 to the load lock unit 2285. Then, the transfer robot 22821 of the first transfer apparatus 2282 transfers the bonded wafers W1 and W2 from the load lock unit 2285 to the unload port 22812.

[0072] Furthermore, the bonding system according to this embodiment, in particular, directly bonds the bonds generated on the bonding surfaces of the workpieces in an ultra-high vacuum environment where almost no other molecules are present, by irradiating the workpieces with a particle beam to activate the bonding surfaces and generating bonds on the bonding surfaces. In particular, the metal regions are made of a material that is easily bonded, such as Cu. Therefore, bonding is easiest when the metal regions protrude beyond the insulator regions, and next, it is preferable for the metal regions and the insulator regions to be flush with each other. When the surface roughness is 10 nm or less, the workpieces can be naturally bonded to each other due to the attractive force between the generated bonds. Even if the metal regions are recessed relative to the insulator regions, even if the depth of the metal regions relative to the insulator regions is 10 nm or less, preferably 1 nm or less, the workpieces can be bonded to each other. Furthermore, if the areas of the metal regions are relatively large, bonding proceeds after partial contact even if the depth is 10 nm or less. On the other hand, if the areas of the metal regions are small, bonding may not proceed unless the depth is 1 nm or less. For example, if the area of ​​the metal region is 10,000 nm for the aforementioned depth of 10 nm, ２ In other words, if there is a gap of 1 nm to 10 nm between the metal regions, if the area of ​​the metal regions is large, bonding will naturally proceed when even a part of the metal regions comes into contact, but if the area is small, there is no contact in part, and bonding will not proceed.

[0073] Therefore, when the bonding surfaces of the wafers W1 and W2 include a metal region and an insulator region and these are flush with each other, the surface roughness of the metal region may be 10 nm or less. Here, the bonding surfaces of the wafers W1 and W2 correspond to the irradiation surfaces irradiated with the particle beam in the activation treatment device 2203 and the bonding device 2201. Furthermore, as shown in Figure 31A, it is preferable that the bonding surfaces of the wafers W1 and W2 include metal regions M1 and M2 and insulator regions I1 and I2, and that the metal regions M1 and M2 protrude compared to the insulator regions I1 and I2.

[0074] 31B, the bonding surfaces of the wafers W1 and W2 may include metal regions M1 and M2 and insulator regions I1 and I2, with the metal regions M1 and M2 recessed relative to the insulator regions I1 and I2. Here, the depth WS2 of the metal regions M1 and M2 relative to the insulator regions I1 and I2 is preferably a distance that allows the metal regions M1 and M2 to bond naturally with the insulator regions I1 and I2 in contact with each other, and is preferably 1 nm to 10 nm or less. Specifically, for example, when the area of ​​the metal regions is 10,000 nm or less, the depth WS2 may be 1 nm to 10 nm or less. ２ If the depth WS2 is 10 nm or less, the area of ​​the metal region may be 10,000 nm or less. ２ If it is less than 1 nm, the depth WS2 is preferably 1 nm or less.

[0075] In this direct bonding method using particle beams, metal regions can be easily bonded together, but the bonding strength between insulator regions formed from oxide films or the like does not increase. For example, when the bonding strength between metal regions is 2 J / m ２ or more, whereas the bonding strength between the insulating regions is 0.5 J / m ２ The bonding strength between the insulator regions is reduced to below 1000 kJ / cm. Therefore, a configuration in which, for example, a particle beam containing Ar and a particle beam containing Si can be simultaneously irradiated onto the insulator region is preferable. Specifically, by arranging Si inside the housing of the particle beam source or in the region irradiated with the particle beam emitted from the particle beam source, the particle beam containing Ar and the particle beam containing Si can be irradiated onto the metal region and the insulator region, and the bonding strength between the insulator regions can be increased via the Si adhering to the insulator regions.

[0076] In addition, the bonding system according to this embodiment may bond a wafer W1 including a metal region M1 and an insulator region I1, where the metal region M1 and the insulator region I1 are flush with each other, as shown in FIG. 32A , to a wafer W2 including a metal region M2 and an insulator region I2, where the metal region M2 and the insulator region I2 are flush with each other. In this case, as shown in FIG. 32A , Si particles may be deposited on the metal region M1 and the insulator region I1. However, in the bonding system according to this embodiment, a particle beam including Ar particles or the like is irradiated onto the bonding surface of the wafer W1, as shown in FIG. 32B , so that Si particles do not accumulate on the bonding surface to form a layer. Therefore, even when wafers W1 and W2 including metal regions M1 and M2 and insulator regions I1 and I2 are bonded together, electrical short-circuiting between adjacent metal regions M1 and M2 through the Si layer can be prevented.

[0077] As described above, in the particle beam source 22361 of the activation treatment device 2203 and the particle beam sources 22161 and 22162 of the bonding device 2201 according to this embodiment, at least the portions of the anode 2211 and the cathode 2212 that are exposed to the inside of the housing 14 are made of Si. This prevents carbon particles from being emitted from the particle beam sources 22361, 22161, and 22162, and therefore prevents the carbon particles emitted from the particle beam sources 22361, 22161, and 22162 from adhering to the bonding surfaces of the wafers W1 and W2.

[0078] If the anode is made of carbon, Si adhering to the anode may be discharged outside the housing 14. In contrast, the portions of the anode 2211 and the cathode 2212 exposed to the inside of the housing 14 are made of Si, are plate-shaped, and are arranged opposite each other in the thickness direction, so-called parallel plate types. This suppresses the adhesion of Si to the anode 2211, and therefore reduces the amount of Si fine particles discharged outside the housing 14.

[0079] Furthermore, in the activation treatment device 2203 according to this embodiment, an airflow is generated in the chamber 22320, flowing from the stage toward the particle beam source 22361. This forces particles floating near the wafers W1 and W2 held on the stage 22341 in the chamber 22320 to be carried by the airflow and forcibly expelled outside the chamber 22320, thereby suppressing particle adhesion to the wafers W1 and W2. In the activation treatment device 2203, the type of so-called reactive gas contained in the particle beam and the type of so-called particle prevention gas flowing from near the wafers W1 and W2 into the chamber 22320 are not particularly limited. Both may be inert gases such as Ar, Xe, or Ne, or other gases. To prevent metal contamination, it is preferable to cover the particle beam irradiation area except for the wafers W1 and W2 with a non-metallic material such as Si, glass, or ceramics. Furthermore, by using Si, etched Si particles can be irradiated onto the bonding surfaces of the wafers W1 and W2.

[0080] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the above-described embodiments. For example, particle beam sources 15001 and 16001 shown in FIGS. 33 and 34 may further include a magnetic field generator for applying a magnetic field parallel to the central axis of the anode 11 and the cathode 12 in addition to the configuration of the particle beam source 4001 shown in FIG. 11 . In the particle beam source 15001 shown in FIG. 34 , an air-core coil 33 is provided as the magnetic field generator. The air-core coil 33 is arranged so that its winding axis is parallel to the opposing direction of the anode 11 and the cathode 12. The air-core coil may be arranged, for example, at each of both longitudinal ends of the housing 4014 so that its winding axis is perpendicular to the opposing direction of the anode 11 and the cathode 12, i.e., along the longitudinal direction of the housing 4014. The housing 4014 may be, for example, in the shape of a long box. This suppresses sputtering on the sidewalls of the housing 4014. In the particle beam source 16001 shown in Fig. 34, a magnet 34 is provided as a magnetic field generating unit. Other configurations and operations are similar to those of the particle beam source 4001 shown in Fig. 11 or the particle beam source 15001 shown in Fig. 33. The air-core coil 33 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 34 is provided outside the anode 11 so as to generate a magnetic field parallel to the central axes of the anode 11 and the cathode 12.

[0081] 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, which can prevent collisions with the side surfaces and the generation of carbon particles due to sputtering. ＋ Since this has no effect on the movement of the particle beam, it is possible to extend the life of the side portion and reduce carbon particles without affecting the generation of the particle beam.

[0082] 35A and 35B , the particle beam source 17001 may further include magnetic field generators 17034 and 17035 for applying a magnetic field parallel to the central axis perpendicular to the opposing direction of the anode 11 and the rectangular plate-shaped cathode 17012. In FIGS. 35A and 35B , components similar to those of the particle beam source 4001 according to the fourth embodiment are denoted by the same reference numerals as in FIG. 11 . A radiation port 17016 having a long, rectangular shape in a plan view and extending along the longitudinal direction is formed in the approximate center of the cathode 17012. The magnetic field generators 17034 and 17035 each include a long, plate-shaped permanent magnet 17341 or 17351 magnetized in the thickness direction, and spacers 17342 or 17352 supporting the permanent magnets 17341 or 17342 at their distal ends and fixed to the outer wall of the housing 4014 at their proximal ends. The magnetic field generating units 17034, 17035 are arranged on both sides of the housing 4014 in the p-axis direction, with the permanent magnets 17034, 17035 facing each other with opposite polarities. Within the housing 4014, as shown by the arrow AR1701 in FIG. 35A , an electric field is generated in a direction from the anode 11 toward the cathode 17012. Furthermore, as shown by the arrow AR1702 in FIG. 35B , a magnetic field is formed parallel to the cathode 17012. This improves the plasma density generated between the anode 11 and the cathode 17012, thereby enabling a reduction in the Ar flow rate and an improvement in the intensity of the particle beam.

[0083] 36A and 36B , particle beam source 18001 may further include two pairs of magnetic field generators 18034 and 18035 for applying a magnetic field parallel to the central axis in a direction perpendicular to the opposing direction of anode 11 and rectangular plate-shaped cathode 17012. In Figures 36A and 36B , the same components as those of particle beam source 4001 according to embodiment 4 and the aforementioned particle beam source 17001 are denoted by the same reference numerals as in Figures 11 , 35A, and 35B . Magnetic field generators 18034 and 18035 each include long, plate-shaped permanent magnets 18341 and 18351 magnetized in the thickness direction, and spacers 18342 and 18352 supporting permanent magnets 18341 and 18342 at their distal ends and fixed to the outer wall of housing 4014 at their proximal ends. An electric field is generated within the housing 4014 in a direction from the anode 11 to the cathode 17012, as indicated by the arrow AR1801 in Fig. 36A. Furthermore, as indicated by the arrows AR1802 and AR1803 in Fig. 36B, a first magnetic field and a second magnetic field are formed by two pairs of magnetic field generating units 18034 and 18035 disposed on either side of the longitudinal center of the radiation port 15011a. Here, the directions of the magnetic fields generated by the two pairs of magnetic field generating units 18034 and 18035 are opposite to each other. That is, the two sets of magnetic field generating units 18034, 18035 generate the first and second magnetic fields described above so that the direction of the first magnetic field generated on one side of the projection area of ​​the emission port 17016 in the cathode 17012 in the opposing direction of the anode 11 and cathode 17012 is opposite to the direction of the second magnetic field generated on the other side. This makes it possible to increase the plasma density in the area between the first and second magnetic fields compared to the particle beam source 17001 shown in Figures 35A and 35B, and to make the intensity distribution of the particle beam emitted from the emission port 17016 uniform.

[0084] 37 , the particle beam source 19001 may have a plurality of pairs of magnetic field generators 18034, 18035 arranged along the longitudinal direction of the housing 4014. Two pairs of magnetic field generators 18034, 18035 adjacent to each other along the longitudinal direction of the housing 4014 are arranged such that the direction of the magnetic field generated by one pair is opposite to the direction of the magnetic field generated by the other pair. In this case, regions of high magnetic flux density and regions of low magnetic flux density are alternately generated along the longitudinal direction of the cathode 19012. Therefore, the size of the emission hole 19016A, which is positioned opposite the region of high magnetic flux density, is set to be smaller than the size of the emission hole 19016B, which is positioned opposite the region of low magnetic flux density, thereby making the irradiation intensity of the particle beam emitted from the particle beam source 19001 uniform. 37 , when the shapes of the emission holes 19016A and 19016B are circular, the diameter D19016A of the emission hole 19016A is shorter than the diameter D19016B of the emission hole 19016B. Alternatively, the emission holes may be provided so as to penetrate in a direction inclined with respect to the thickness direction of the cathode 19012, so that the emission direction of the particle beam from some of the emission holes arranged opposite the region of high magnetic flux density is aligned with the emission direction of the particle beam emitted from the emission holes arranged opposite the region of low magnetic flux density. This may also make the overall irradiation intensity of the particle beam emitted from the particle beam source 19001 uniform.

[0085] 38 , the magnetic field generating units 20034, 20035 may each include a long, plate-shaped permanent magnet 20341, 20351 magnetized in the thickness direction, and a spacer 20342, 20352 supporting the permanent magnets 20341, 20342 at its tip and fixed to the outer wall of the casing 4014 at its base, with one longitudinal end of the permanent magnets 20341, 20351 being positioned closer to the region between the anode 11 and the cathode 17012 than the other longitudinal end. That is, the permanent magnets 20341, 20351 may be positioned at an angle with respect to the side wall of the casing 4014. This makes it possible to increase the magnetic flux density in regions facing both ends of the radiation hole 17016 in the casing 4014 compared to the magnetic flux density in a region facing the center, thereby making the plasma density uniform throughout the entire longitudinal direction of the region facing the radiation hole 17016 in the casing 4014. Therefore, the intensity of the particle beam emitted from the emission hole 17016 can be made uniform.

[0086] 39 , the particle beam source 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 inlet 7015. Here, a portion 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.

[0087] In the first embodiment, for example, as shown in FIG. 40A , the cathode 12012 may be provided with a long, plate-like cathode 12012 having a single long, slit-shaped emission hole 12016 formed therein. Here, the emission hole ratio of the emission hole 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. 40B , the cathode 8012 may be provided with a long, plate-like cathode 8012 having a plurality of long, slit-shaped emission holes 8016 formed therein. Note that the number of emission holes 8016 in the cathode 8012 is not particularly limited. The emission holes 8016 are each formed along the longitudinal direction of the cathode 8012. Here, the emission hole ratio of the emission hole 8016 to the total area of ​​the cathode 8012 is preferably 50% or more. In the particle beam source according to this modification, ions generated inside the housing pass through the emission hole 8016 and are emitted to the outside of the housing. Therefore, for example, it is preferable that the wafer to be irradiated with the particle beam is a wafer that is allowed to be charged up.

[0088] Incidentally, in a particle beam source equipped with a cathode 13012 having a plurality of emission holes 13016 formed therein as shown in Fig. 40C, the emission hole ratio is normally less than 10%, but by widening the area in which emission holes 14016 are formed in cathode 14012 as shown in Fig. 40D, the emission hole ratio can be increased to 30%. Also, by making emission holes 12016 of cathode 12012 slit-shaped as shown in Fig. 40A, the emission hole ratio can be increased to 30%, and by widening the area in which emission holes are formed in cathode 8012 as shown in Fig. 40B, the emission hole ratio can be increased to 50%. Although these emission holes 13016, 14016 are drawn at equal pitches in Figs. 40C and 40D, they may also be drawn at unequal pitches. When a particle beam is irradiated obliquely, the particle beam that reaches the wafer surface farther from the particle beam source is diffused, resulting in a reduced etching rate. However, by providing an uneven pitch such that the pitch of the row of emission holes is closer to the wafer surface, the reduced etching rate can be compensated for. Similarly, the etching rate generally tends to decrease at both ends of the wafer, but this can be compensated for by providing an uneven pitch at both ends of the row of emission holes. In the present invention, the low argon flow rate and the fact that almost no argon gas flows out of the emission holes result in a highly linear particle beam, and the effect of providing the emission holes with an uneven pitch is particularly significant.

[0089] In the first to fifth embodiments, for example, a magnetic field generating unit may be provided that generates a magnetic field perpendicular to the opposing direction of the anode and the cathode. Here, the magnetic field generating unit may have a permanent magnet 5018 as a magnetic field generating unit that generates a magnetic field perpendicular to the opposing direction of the anode 11 and the cathode 12 in the housing 14, as shown in FIG. 41. This allows the Ar present inside the housing 14 to be ＋ The ions are prevented from colliding with the inner wall of the housing 14 and are guided in a direction toward the cathode emission port. ＋ It is possible to further reduce carbon particles generated by sputtering of the housing 14 by ions. Although an example in which the anode 11 is flat has been described in FIG. 41, it is also possible to use a configuration in which, for example, two columnar anodes are disposed inside the housing 14.＋ The method for generating plasma containing ions is not particularly limited, and an inductive coupling method, a microwave introduction method, or the like can be adopted.

[0090] Alternatively, the particle beam source may include a cylindrical housing, a cathode having an emission hole formed therein and disposed at one end of the housing in the axial direction of the cylinder, an anode disposed at the other end of the housing in the axial direction of the cylinder, and a gas introduction unit. ＋ The magnetic field generating unit generates a magnetic field perpendicular to the thickness direction of the cathode as shown in Fig. 1 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 opposite directions. The yokes are made of, for example, ferrite. The permanent magnets can be, for example, neodymium magnets. By generating a magnetic field, Ar ＋ The direction of ion flight is more directed toward the radiation hole, which prevents etching of the sidewalls of the housing, thereby suppressing the generation of particles. Here, the ends of the two yokes opposite the permanent magnet side are arranged outside the housing so as to face each other in a direction perpendicular to the cylindrical axis direction of the housing. The permanent magnets may be arranged in a position facing the sidewalls of the housing, or on the back side of the housing opposite the radiation hole side. The housing may be, for example, in the shape of a long box.

[0091] In the fifth embodiment, an example has been described in which the anodes 5011 are arranged in parallel in a direction perpendicular to the radiation direction of the particle beam, but this is not limiting, and the anodes 5011 may be arranged in parallel along the radiation direction of the particle beam.

[0092] In the sixth embodiment, the particle beam sources 2161 and 2162 are fixed to the stage 2141 and the head 2142, respectively. However, this is not limiting. For example, as shown in FIG. 42 , the particle beam sources 2161 and 2162 may not be fixed to the stage 2141 and the head 2142, respectively. In FIG. 42 , the same components as those in the embodiment are denoted by the same reference numerals as in FIG. 21 . The bonding apparatus according to this modification includes a horizontal drive unit 3163 that collectively supports the particle beam sources 2161 and 2162 and moves the particle beam sources 2161 and 2162 in a horizontal direction perpendicular to the opposing direction of the wafers W1 and W2. In the bonding apparatus according to this modification, as shown in FIG. 43 , the particle beam sources 2161 and 2162 move as indicated by arrow AR32 while irradiating the bonding surfaces of the wafers W1 and W2 with particle beams.

[0093] In the bonding apparatus described in the sixth embodiment, the distance between the particle beam sources 2161 and 2162 and the wafers W1 and W2 changes during irradiation of the particle beams onto the wafers W1 and W2, which changes the dose of the particle beams irradiated onto the wafers W1 and W2, and accordingly changes the etching rate of the surfaces of the wafers W1 and W2. In contrast, according to the present configuration, the particle beams can be irradiated onto the wafers W1 and W2 while maintaining a constant distance between the particle beam sources 2161 and 2162 and the wafers W1 and W2, so that the dose of the particle beams irradiated onto the wafers W1 and W2 can be made uniform while keeping the moving speed of the particle beam sources 2161 and 2162 constant.

[0094] In the sixth embodiment, the distance between the stage 2141 and the head 2142 may be fixed.

[0095] In the sixth embodiment, an example in which two wafers W1 and W2 are simultaneously irradiated with a particle beam has been described, but the present invention is not limited to this. For example, as shown in Fig. 44, the wafers W1 and W2 may be held one by one below the stage 4140, and the particle beam from the particle beam source 2161 may be irradiated to the wafers W1 and W2 sequentially. Then, when the process of irradiating the wafer W1 with the particle 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 by the head 4142 in the same position.

[0096] In the fifth embodiment, an example of a bonding apparatus including two particle beam sources 2161 and 2162 has been described. However, the present invention is not limited to this. For example, as shown in FIG. 45 , the bonding apparatus may include one particle beam source 5161 and an attitude changer (not shown) that changes the attitude of the particle beam source 5161 to change the irradiation direction of the particle beam from the particle beam source 5161. The attitude changer may change the attitude of the particle beam source 5161 as indicated by arrow AR51 to irradiate the particle beam onto the wafer W1 held on the stage 5141 or onto the wafer W2 held on the head 5142. Furthermore, each component may be positioned such that the +Y direction in FIG. 45 is vertically upward. In this case, the emission hole of the particle beam source 5161 does not face vertically downward, thereby suppressing adhesion of particles to the bonding surfaces of the wafers W1 and W2.

[0097] 46 , the bonding apparatus may include a particle beam source 5161, an attitude changer for changing the attitude of the particle beam source 5161, and a horizontal drive unit (not shown) for collectively supporting the atom generator 5161 and the attitude changer and for moving the particle beam source 5161 and the attitude changer in a horizontal direction perpendicular to the opposing direction of the wafers W1 and W2. In this case, the particle beam source 5161 may be moved as shown by arrow AR62 while the particle beam source 5161 is positioned so that its irradiation direction is directed toward the stage 6141 holding the wafer W1, and then the particle beam source 5161 may be moved as shown by arrow AR62 while the particle beam source 5161 is positioned so that its irradiation direction is directed toward the head 6142 holding the wafer W2.

[0098] Alternatively, as shown in FIG. 47, the bonding apparatus may be provided with an attitude changer that changes the attitude of the particle beam source 5161, and a head drive unit (not shown) that moves the head 5142 holding the wafer W2 in the vertical direction as shown by the arrow AR71.

[0099] 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.

[0100] In the embodiment, the housing may be a long box-like structure in which the anode and the long plate-like cathode are disposed inside. The cathode may have a plurality of radiation holes formed along its longitudinal direction.

[0101] 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 the first magnetic field and the second magnetic field within the cathode so that the magnetic field direction is leftward for the first magnetic field and rightward for the second magnetic field when viewed from the cathode side with the first magnetic field above the second magnetic field, and may guide the generated positive ions to the emission hole.

[0102] In the sixth embodiment, the particle beam source may include a first particle beam source that irradiates a region including at least a part of a joining surface of one of the two objects with a particle beam, and a second particle beam source that irradiates a region including at least a part of a joining surface of the other of the two objects with a particle beam. Each of the first particle beam source and the second particle beam source may be in the shape of a long box and have a housing inside which an anode and a cathode are disposed, the cathode may be in the shape of a long plate, and a plurality of emission holes may be formed in the cathode along the longitudinal direction of the cathode.

[0103] In the seventh embodiment, the particle beam sources 22161 and 22162 are fixed to the stage 2141 and the head 2142, respectively. However, this is not limiting, and for example, as shown in FIG. 48 , the particle beam sources 22161 and 22162 may not be fixed to the stage 2141 and the head 2142, respectively. In FIG. 48 , the same components as those in the seventh embodiment are denoted by the same reference numerals as those in FIG. 28 . The bonding apparatus according to this modification includes a horizontal drive unit (not shown) that collectively supports the particle beam sources 22161 and 22162 and moves the particle beam sources 22161 and 22162 in a horizontal direction perpendicular to the opposing direction of the wafers W1 and W2. In the bonding apparatus according to this modification, the particle beam sources 22161 and 22162 move as indicated by arrow AR2232 while irradiating the bonding surfaces of the wafers W1 and W2 with particle beams. In addition, in this configuration, for example, an airflow may be generated between the stage 2141 and the head 2142 by introducing gas between the stage 2141 and the head 2142 as indicated by arrow AR2233 and discharging the gas as indicated by arrow AR2234. This allows particles present near the bonding surfaces of the wafers W1 and W2 to be carried by the airflow and discharged behind the particle beams 22161 and 22162. Furthermore, the particle beam sources 22161 and 22162 move only within the region between the wafers W1 and W2, i.e., only within the region outside the region between the two dashed lines in the Y-axis direction. This prevents particles generated by the particle beam sources 22161 and 22162 from falling onto the wafer W1. Furthermore, a vacuum pump for discharging gas from the housing 14 of the particle beam sources 22161 and 22162 and a vacuum pump for discharging gas from the chamber inside which the stage 2141 and head 2142 are located may be separately arranged behind the particle beam sources 22161 and 22162.

[0104] 42 , two particle beam sources 2161 and 2162 are arranged spaced apart in the Y-axis direction, so sufficient space is required to arrange the particle beam sources on both sides of the stage 2141 and head 2142 in the Y-axis direction. In contrast, with the present configuration, the particle beam sources 22161 and 22162 are arranged side by side in the Z-axis direction, so sufficient space is required to arrange the particle beam sources on only one side of the stage 2141 and head 2142 in the Y-axis direction, thereby enabling the overall apparatus to be made more compact. Furthermore, with this configuration, the distance between the bonding surface of the wafer W1 held on the stage 2141 and the bonding surface of the wafer W2 held on the head 2142 can be made shorter than the same distance in the configuration described with reference to FIG. 42 , enabling the overall apparatus to be made more compact.

[0105] Furthermore, according to this configuration, by overlapping at least a portion of the irradiation areas of the particle beams emitted from the particle beams 22161 and 22162, the inclination angle of the irradiation direction of the particle beam sources 22161 and 22162 with respect to the perpendicular to the bonding surface can be made acute, thereby improving the etching ability accordingly.

[0106] 48 may further include a swing drive unit (not shown) that swings the two particle beam sources 22161 and 22162 to change the radiation direction of the particle beams of the particle beam sources 22161 and 22162. The two particle beam sources 22161 and 22162 may move horizontally while changing the radiation direction of their particle beams, or the two particle beam sources 22161 and 22162 may change the radiation direction of their particle beams while their horizontal positions are fixed. Furthermore, the components may be positioned such that the +Y direction in FIG. 48 is vertically upward. In this case, the radiation holes of the particle beam sources 22161 and 22162 do not face vertically downward, thereby suppressing particle adhesion to the bonding surfaces of the wafers W1 and W2.

[0107] Furthermore, in the configuration shown in FIG. 48, instead of the two particle beam sources 22161 and 22162, one particle beam source and a swing drive unit for swinging the particle beam source may be provided.

[0108] In the seventh embodiment, the activation treatment device 2203 and the bonding device 2001 may each include particle beam sources 23361, 23161, and 23162 as shown in FIG. 49 . The particle beam sources 23361, 23161, and 23162 include a housing 5014, an anode 5011, a cathode 23012, and a gas supply source 30. In FIG. 49 , the same components as those in the fifth embodiment are denoted by the same reference numerals as in FIG. 13 . The housing 5014 is a long rectangular box with one side open along its longitudinal direction. The cathode 23012 is formed from silicon in a long rectangular box shape and is disposed inside the housing 5014. The anode 5011 is disposed at a position spaced apart from the inner peripheral wall of the housing 5014. The cathode 23012 has a first portion 23121 in its peripheral wall that is exposed to the outside of the housing 5014, and multiple emission holes 23121a that emit particle beams are formed in that first portion 23121. The cathode 23012 is plate-shaped, with its peripheral portion continuing to the inner wall and an opening 23122a formed in the center, and also has a second portion 23122 that is arranged to divide the inside of the cathode 23012 into a region where the anode 5011 is arranged and a region on the first portion 23121 side. A gas inlet hole 23012c that introduces Ar gas into the cathode 5012 is formed in a portion of the peripheral wall of the cathode 23012 that faces the first portion 23121.

[0109] According to this configuration, adhesion of Si scattered from the cathode 23012 to the anode 5011 can be suppressed, and therefore, release of Si particles adhered to the anode 5011 to the outside of the housing 5014 can be suppressed.

[0110] In each embodiment, the particle beam emitted from the particle beam source is not limited to one containing Ar.

[0111] It should be noted that claim 1 includes all variations of the particle beam source described in the first to fifth embodiments and the modified examples.

[0112] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is defined 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.

[0113] This application is based on Japanese Patent Application No. 2024-031875 filed on March 4, 2024, and Japanese Patent Application No. 2024-148321 filed on August 30, 2024. The entire specifications, claims and drawings of Japanese Patent Application No. 2024-031875 and Japanese Patent Application No. 2024-148321 are incorporated herein by reference.

[0114] The present invention is suitable for manufacturing, for example, CMOS (Complementary MOS) image sensors, memories, computing elements, and MEMS (Micro Electro Mechanical Systems).

[0115] 1, 2001, 3001, 4001, 2161, 2162, 7010, 15001, 16001, 17001, 18001, 19001, 20001: particle beam source, 11, 7011, 21602: anode, 12, 7012, 8012, 17012, 19012, 21601: cathode, 13, 3013, 21604: insulating part, 14, 4014, 7014: housing, 15: cover, 16 , 8016, 17016, 19016A, 19016B, 21601a: radiation hole, 17, PLM: plasma, 18: electron, 19: particle 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, 21604: gas supply source, 2120: chamber, 2121a : vacuum pump, 2121b: exhaust pipe, 2121c: exhaust valve, 2122A, 2122B: particle beam source support, 2141: stage, 2142: head, 2143: stage drive unit, 2144: head drive unit, 2150: positional deviation amount measurement unit, 4015, 7015, 10015: gas introduction unit, 5018, 17341, 17351, 18341, 18351, 20341, 20351: permanent magnet Stone, 17342, 17352, 18342, 18352, 20342, 20352: Spacer, 21411, 21421: Wafer heating unit, 21441: Elevation driving unit, 21441a, 21445: Pressure sensor, 21442: XY direction driving unit, 21443: Rotation driving unit, 21444: Piezo actuator, 21601: Housing, J1, J2: Irradiation axis, n1, n2: Perpendicular line, W1, W2: Wafer

Claims

1. A particle beam source comprising: a box-shaped housing having an opening formed in part of a peripheral wall, and a first exhaust hole formed in the peripheral wall excluding the opening, for exhausting gas present inside the housing to the outside of the housing; an anode disposed inside the housing; a cathode covering the opening and disposed spaced from the anode, the cathode having at least one emission hole formed therein that penetrates from a part exposed inside the housing to a part exposed outside the housing and emits a particle beam; a gas supply source that introduces gas to a position inside the housing closer to the cathode than the first exhaust hole; and a voltage application unit that applies a voltage between the anode and the cathode, wherein a gas flow is generated inside the housing that flows from the gas supply source to a position inside the housing closer to the cathode than the first exhaust hole, flows in a direction away from the cathode, and exits through the first exhaust hole.

2. A particle beam source according to claim 1, wherein an average radiation direction of the particle beam emitted from the at least one emission hole and an average flow direction of the gas flow are opposite to each other.

3. A particle beam source according to claim 1 or 2, wherein a gas inlet hole is formed in the housing or the cathode, penetrating from the part exposed on the inside of the housing to the part exposed on the outside of the housing, for introducing gas from the outside of the housing into the inside of the housing.

4. A particle beam source according to claim 3, wherein the gas introduction hole is formed in a portion of the cathode surrounding a portion in which the at least one emission hole is formed.

5. A particle beam source according to claim 3, wherein the gas inlet hole is formed in a portion of the peripheral wall of the housing closer to the cathode than the first exhaust hole.

6. A particle beam source according to claim 1 or 2, wherein the gas supply introduces gas into the inside of the housing through the at least one emission hole.

7. A particle beam source according to claim 1 or 2, further comprising a cover arranged to cover the cathode from the outside of the housing, the cover having at least one transmission hole formed in a portion facing each of the at least one emission hole in the emission direction of the particle beam emitted from the at least one emission hole, the transmission hole allowing the particle beam to pass from the cathode side to the opposite side of the cathode side, and the gas supply unit introducing gas through a region between the cathode and the cover.

8. A particle beam source according to claim 7, wherein the opening area of ​​each of said at least one transmission aperture is larger than the opening area of ​​an emission aperture facing said at least one transmission aperture in the emission direction of said particle beam.

9. A particle beam source according to claim 1 or 2, wherein the anode is cylindrical.

10. A particle beam source according to claim 1 or 2, wherein the cathode is box-shaped and has a first section in which the at least one radiation hole is formed in the peripheral wall, and a second section whose peripheral section is continuous with the inner wall of the cathode, has an opening formed in the center, and is arranged to separate the inside of the cathode into a region in which the anode is arranged and a region of the first section.

11. A particle beam source according to claim 10, wherein the first portion and the second portion are flat and arranged to face each other in the thickness direction, and the distance between the first portion and the second portion is 10 mm or more and 24 mm or less.

12. A particle beam source according to claim 10, wherein the distribution of irradiation intensity of the particle beam can be controlled by changing the shape and size of the opening formed in the second portion.

13. A particle beam source according to claim 1 or 2, further comprising a magnetic field generating unit that generates a magnetic field inside the housing, at least some of whose magnetic field lines intersect with the opposing direction of the anode and the cathode.

14. A particle beam source according to claim 1 or 2, wherein the anode is plate-shaped, and at least a part of one surface in the thickness direction faces the cathode.

15. The particle beam source according to claim 14, further comprising a magnetic field generating unit that generates a magnetic field inside the housing, at least some of whose magnetic field lines intersect with the opposing direction of the anode and the cathode.

16. A particle beam source according to claim 15, wherein the magnetic field generating unit generates the first magnetic field and the second magnetic field such that the direction of the first magnetic field generated on one side of a projection area in the opposing direction of the emission area in which the at least one emission port is provided in the cathode is opposite to the direction of the second magnetic field generated on the other side.

17. A particle beam source according to claim 16, wherein first magnetic field generating units that generate a first magnetic field in a direction perpendicular to the thickness direction of the cathode and along one of the shorter sides of the cathode, and second magnetic field generating units that generate a second magnetic field in a direction opposite to that of the first magnetic field, are alternately arranged along the longer side of the cathode.

18. A particle beam source as described in claim 15, wherein the size of the first radiation hole arranged at a position facing the region of high magnetic flux density is set to be smaller than the size of the second radiation hole arranged at a position facing the region of low magnetic flux density.

19. A particle beam source as described in claim 14, wherein the first emission holes are arranged to penetrate in a direction inclined with respect to the thickness direction of the cathode so that the emission direction of a particle beam from at least one of the plurality of first emission holes arranged at a position facing the region of high magnetic flux density is aligned with the emission direction of a particle beam emitted from the plurality of emission holes arranged at a position facing the region of low magnetic flux density.

20. A particle beam source according to claim 14, wherein the magnetic field generating unit has a long permanent magnet, and the permanent magnet is arranged in such a position that one end of the permanent magnet in the longitudinal direction is closer to the region between the anode and the cathode than the other end.

21. A particle beam source according to claim 1 or 2, further comprising a magnetic field generating unit that generates a magnetic field inside the housing, at least some of whose magnetic field lines intersect the opposing direction of the anode and the cathode.

22. A particle beam source according to claim 1 or 2, wherein the surface of the portion inside the housing made of carbon is coated with glassy carbon or a resin that is a precursor of the glassy carbon.

23. A particle beam source according to claim 1 or 2, wherein the anode is plate-shaped, the cathode is plate-shaped, and the anode and the cathode are arranged opposite each other in the thickness direction.

24. A particle beam source according to claim 23, wherein the surface of the portion inside the housing made of carbon is coated with glassy carbon or a resin that is a precursor of the glassy carbon.

25. A particle beam source according to any one of claims 1, 2 and 23, wherein at least the portions of the anode and the cathode exposed to the inside of the housing are made of Si.

26. A particle beam source according to any one of claims 1, 2, 23 and 24, further comprising a cooling mechanism for cooling the cathode.

27. A gas supply device comprising: a first particle beam source that emits a particle beam vertically downward; and a stage that is positioned vertically below the first particle beam source and supports a first object that is irradiated with the particle beam emitted from the first particle beam source, wherein the first particle beam source comprises: a box-shaped housing having an opening formed in a part of its peripheral wall; an anode that is positioned inside the housing; a cathode that covers the opening and is positioned spaced apart from the anode, and has at least one emission hole that penetrates from a part exposed inside the housing to a part exposed outside the housing and through which the particle beam is emitted; a gas supply source that introduces gas into the inside of the housing; and a voltage application unit that applies a voltage between the anode and the cathode, wherein a gas introduction hole that penetrates from the part exposed inside the housing to a part exposed outside the housing and through which gas is introduced from the outside of the housing into the inside of the housing is formed in the housing or the cathode; a first exhaust hole is formed in the housing in a portion of the peripheral wall excluding the opening, for exhausting gas present inside the housing to the outside of the housing; and an airflow is generated inside the housing, flowing from the gas inlet hole, flowing in a direction away from the cathode, and flowing out from the first exhaust hole.

28. A particle beam source further comprising: a second particle beam source that emits a particle beam vertically upward; a head that is positioned vertically above the second particle beam source and supports a second object to be irradiated with the particle beam emitted from the second particle beam source; and a horizontal drive unit that moves either the first particle beam source or the stage in a direction perpendicular to the vertical relative to the other, and moves either the second particle beam source or the head in a direction perpendicular to the vertical relative to the other, wherein the second particle beam source comprises: a box-shaped housing having an opening formed in part of its peripheral wall; an anode positioned inside the housing; a cathode that covers the opening and is positioned spaced from the anode, and has at least one emission hole that penetrates from a part exposed inside the housing to a part exposed outside the housing and emits a particle beam; a gas supply source that introduces gas into the inside of the housing from the gas inlet hole; and a voltage application unit that applies a voltage between the anode and the cathode, 28. The bonding system according to claim 27, wherein a gas inlet hole is formed in the housing or the cathode, the gas inlet hole passing through from a portion exposed to the inside of the housing to a portion exposed to the outside of the housing, for introducing gas from outside the housing to inside the housing; a first exhaust hole is formed in the housing in a portion excluding the opening in the peripheral wall, for exhausting gas present inside the housing to the outside of the housing; and an airflow is generated inside the housing, flowing in from the gas inlet hole, flowing in a direction away from the cathode, and flowing out from the first exhaust hole.

29. The bonding system of claim 28, wherein the first particle beam source and the second particle beam source are arranged such that an emission area of ​​a particle beam emitted from the first particle beam source and an emission area of ​​a particle beam emitted from the second particle beam source at least partially overlap.

30. The bonding system described in claim 27 or 28, further comprising: a chamber in which the first particle beam source and the stage are disposed; and a second gas supply source for introducing gas into the chamber, wherein the chamber is formed with a second gas inlet hole for introducing gas into the chamber and a second exhaust hole for exhausting gas present in the chamber to the outside, and wherein gas flowing into the chamber from the second gas supply source through the second gas inlet hole flows out of the second exhaust hole, thereby generating an airflow within the chamber that flows from the stage toward the first particle beam source.

31. The bonding system of claim 30, comprising: a first vacuum pump that exhausts gas present inside the housing through the first exhaust hole; and a second vacuum pump different from the first vacuum pump that exhausts gas present inside the chamber through the second exhaust hole.

32. A bonding system according to any one of claims 27 to 29, wherein the irradiation surface of the first object, which is irradiated with the particle beam, includes a metal region made of metal and an insulator region made of insulator, and the metal region and the insulator region are flush with each other.

33. The joining system of claim 32, wherein the metal region is formed from Cu.

34. A bonding system according to any one of claims 27 to 29, wherein the irradiation surface of the first object that is irradiated with the particle beam includes a metal region made of metal and an insulator region made of insulator, and the metal region protrudes compared to the insulator region.

35. A bonding system according to any one of claims 27 to 29, wherein the irradiation surface of the first object onto which the particle beam is irradiated includes a metal region formed from a metal and an insulator region formed from an insulator, the metal region being recessed relative to the insulator region, and the depth of the metal region relative to the insulator region is 10 nm or less.

36. The bonding method according to any one of claims 27 to 29, wherein the particle beam includes Si particles.

37. A bonding method for irradiating an object with a particle beam emitted from a particle beam source using a particle beam source comprising: a box-shaped housing having an opening formed in part of a peripheral wall and having a first exhaust hole formed in the peripheral wall excluding the opening for exhausting gas present inside to the outside; an anode disposed inside the housing; and a cathode covering the opening and disposed spaced apart from the anode, the cathode having at least one emission hole formed therein that penetrates from a part exposed inside the housing to a part exposed outside the housing and emits a particle beam, wherein an airflow is generated inside the housing, flowing into a position inside the housing closer to the cathode than the first exhaust hole, flowing in a direction away from the cathode, and flowing out of the first exhaust hole.

38. The bonding method according to claim 37, wherein the average radiation direction of the particle beam emitted from the at least one radiation hole and the average flow direction of the gas flow are opposite to each other.

39. The bonding method according to claim 37 or 38, further comprising generating an airflow flowing from the object toward the particle beam source inside a chamber in which the particle beam source and the object are placed.

40. A bonding method according to claim 37 or 38, wherein the irradiation surface of the object onto which the particle beam is irradiated includes a metal region made of metal and an insulator region made of insulator, and the metal region and the insulator region are flush with each other.

41. The bonding method according to claim 40, wherein the metal region is formed from Cu.

42. A bonding method according to claim 37 or 38, wherein the irradiation surface of the object that is irradiated with the particle beam includes a metal region made of metal and an insulator region made of insulator, and the metal region protrudes compared to the insulator region.

43. A bonding method according to claim 37 or 38, wherein the irradiation surface of the object that is irradiated with the particle beam includes a metal region made of metal and an insulator region made of insulator, and the metal region is recessed compared to the insulator region.

44. The bonding method according to claim 37 or 38, wherein the particle beam includes Si particles.

45. A particle beam source comprising: a box-shaped housing having an opening formed in a portion of a peripheral wall; a plate-shaped anode arranged inside the housing; a cathode covering the opening and arranged spaced apart from the anode, the cathode having at least one emission hole formed therein, which penetrates from a portion exposed inside the housing to a portion exposed outside the housing and emits a particle beam; a gas supply source which introduces gas into the inside of the housing; and a voltage application unit which applies a voltage between the anode and the cathode.

46. ​​A first particle beam source that emits a particle beam vertically downward; a stage that is positioned vertically below the first particle beam source and supports a first object that is irradiated with the particle beam emitted from the first particle beam source; a second particle beam source that emits a particle beam vertically upward; a head that is positioned vertically above the second particle beam source and supports a second object that is irradiated with the particle beam emitted from the second particle beam source; a particle beam source drive unit that oscillates or moves the first particle beam source and the second particle beam source outside a region between the first object and the second object; a chamber in which the first particle beam source, the second particle beam source, the stage, and the head are positioned; and a first gas supply source that introduces gas into a region between the first object and the second object from a side opposite to the first particle beam source and the second particle beam source outside the region between the first object and the second object in the chamber. a first vacuum pump that exhausts gas introduced into a region between the first object and the second object from a side where the first particle beam source and the second particle beam source are disposed relative to the region between the first object and the second object, wherein the first particle beam source and the second particle beam source have: a box-shaped housing having an opening formed in a part of a peripheral wall; an anode disposed inside the housing; a cathode that covers the opening and is disposed spaced apart from the anode, the cathode having at least one emission hole formed therein that penetrates from a part exposed inside the housing to a part exposed outside the housing and emits a particle beam; a second gas supply source that causes gas to flow in from the opening side inside the housing; and a voltage application unit that applies a voltage between the anode and the cathode, and further comprises a second vacuum pump that exhausts gas present inside the housing from the side inside the housing opposite to the opening side, the first particle beam source and the second particle beam source are arranged such that an emission region of a particle beam emitted from the first particle beam source and an emission region of a particle beam emitted from the second particle beam source at least partially overlap with each other.

47. The bonding system of claim 46, wherein the first vacuum pump is separate from the second vacuum pump.

48. A bonding method comprising: arranging a first object to be irradiated with a particle beam emitted from a first particle beam source vertically below the first particle beam source that emits a particle beam vertically downward; and arranging a second object to be irradiated with a particle beam emitted from a second particle beam source vertically above the second particle beam source inside a chamber; moving one of the first particle beam source and the stage in a direction perpendicular to the vertical relative to the other while irradiating the first object with a particle beam from the first particle beam source; and moving one of the second particle beam source and the head in a direction perpendicular to the vertical relative to the other while irradiating the second object with a particle beam from the second particle beam source, the method comprising: the first particle beam source and the second particle beam source comprising: a box-shaped housing having an opening formed in a part of a peripheral wall; an anode disposed inside the housing; a cathode covering the opening and disposed spaced apart from the anode, the cathode having at least one emission hole formed therein that penetrates from a portion exposed inside the housing to a portion exposed outside the housing and that emits a particle beam; a second gas supply source that causes gas to flow in from the opening side inside the housing; and a voltage application unit that applies a voltage between the anode and the cathode, wherein the gas is introduced into the region between the first object and the second object from a side opposite to the first particle beam source and the second particle beam source outside the region between the first object and the second object in the chamber, and the gas introduced into the region between the first object and the second object is discharged from a side where the first particle beam source and the second particle beam source are disposed relative to the region between the first object and the second object, and the gas present inside the housing is discharged to the outside of the housing from a side opposite to the opening side inside the housing, A bonding method, wherein an emission area of ​​the particle beam emitted from the first particle beam source and an emission area of ​​the particle beam emitted from the second particle beam source at least partially overlap with each other.

49. A bonding system for bonding a first object to be bonded and a second object to be bonded, comprising a bonding device that activates the bonding surfaces of the first object to be bonded and the second object to be bonded by irradiating them with a particle beam in an ultra-high vacuum, and then directly bonds the first object to be bonded and the second object to be bonded, wherein the bonding surfaces include a metal region formed from a metal and an insulator region formed from an insulator, and the metal region and the insulator region are flush with each other.

50. A bonding system for bonding a first object to be bonded and a second object to be bonded, comprising a bonding device that activates the bonding surfaces of the first object to be bonded and the second object to be bonded by irradiating them with a particle beam in an ultra-high vacuum, and then directly bonds the first object to the second object to be bonded, wherein the bonding surfaces of the first object to be bonded and the second object to be bonded include a metal region formed from a metal and an insulator region formed from an insulator, and the metal region protrudes compared to the insulator region.

51. A bonding system for bonding a first object to be bonded and a second object to be bonded, comprising a bonding device that, in an ultra-high vacuum, activates the bonding surfaces of the first object to be bonded and the second object to be bonded by irradiating them with a particle beam, and then directly bonds the first object to the second object to be bonded, wherein the irradiation surface of the first object to be bonded, which is irradiated with the particle beam, includes a metal region made of metal and an insulator region made of an insulator, the metal region being recessed compared to the insulator region, and the depth of the metal region relative to the insulator region is 10 nm or less.

52. The joining system of any one of claims 49 to 51, wherein the metal region is formed from Cu.

53. The bonding system of any one of claims 49 to 51, wherein the particle beam comprises Si.

54. A method for bonding a first object to be bonded and a second object to be bonded, comprising the steps of irradiating a particle beam onto the bonding surfaces of the first object to be bonded and the second object to be bonded in an ultra-high vacuum to activate them, and then directly bonding the first object to be bonded and the second object to be bonded, wherein the bonding surfaces include a metal region formed from a metal and an insulator region formed from an insulator, and the metal region and the insulator region are flush with each other.

55. A method for bonding a first object to be bonded and a second object to be bonded, comprising the steps of irradiating a particle beam onto the bonding surfaces of the first object to be bonded and the second object to be bonded in an ultra-high vacuum to activate them, and then directly bonding the first object to be bonded and the second object to be bonded, wherein the bonding surfaces of the first object to be bonded and the second object to be bonded include a metal region formed from a metal and an insulator region formed from an insulator, and the metal region protrudes compared to the insulator region.

56. A method for bonding a first object to be bonded and a second object to be bonded, comprising the steps of irradiating a bonding surface of each of the first object to be bonded and the second object to be bonded with a particle beam in an ultra-high vacuum to activate the bonding surface, and then directly bonding the first object to the second object to be bonded, wherein the irradiation surface of the first object to be bonded, which is irradiated with the particle beam, includes a metal region made of metal and an insulator region made of an insulator, the metal region being recessed compared to the insulator region, and the depth of the metal region relative to the insulator region is 10 nm or less.

57. The bonding method according to any one of claims 54 to 56, wherein the metal region is formed from Cu.

58. The bonding method according to any one of claims 54 to 56, wherein the particle beam includes Si.

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