JP2010221253A - Joining device, joining method, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining technique capable of preventing deposits adhered to one material to be joined from re-adhering to the other material to be joined, when subjecting various kinds of materials to surface activation treatment. <P>SOLUTION: The joint surfaces of both materials 91, 92 to be joined are arranged in parallel and adversely to each other, and further both materials 91, 92 to be joined are arranged in a manner of being mutually deviated in X direction so that the joint surfaces of both materials 91, 92 to be joined are not overlapped as seen from Z direction. In this state, a specific substance (Argon or the like) is discharged by radiation of an atom beam (or an ion beam or the like) from beam radiating parts 11, 21, so that the joint surfaces of both materials 91, 92 to be joined are activated. Thereafter, the joint surfaces of both materials 91, 92 to be joined are relatively moved in the X direction, so that the joint surfaces of both materials to be joined are brought into an opposite state to each other. Further, both materials 91, 92 to be joined, which are in the opposite state, are relatively moved in the Z direction so that they come closer to each other, and both materials to be joined are joined. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a technique for activating and bonding a bonding surface of an object to be bonded.

  There is a technique of joining both objects to be bonded after plasma cleaning (surface activation treatment) of the bonding surfaces of both objects to be bonded in a state where the two objects to be bonded are arranged to face each other.

  However, when the surface activation treatment is performed on both the objects to be bonded in such a facing arrangement state, there is a problem that the objects adhering to one object to be bonded reattach to the other object to be bonded.

  Therefore, there is a technique described in Patent Document 1 as a technique for solving such a problem.

  In the technology of Patent Document 1, both objects to be joined are arranged so as to face each other in a state where their joining surfaces are moved to a lateral position where the joining surfaces do not overlap (in top view), and the joining surfaces of both objects to be joined are arranged. After the plasma cleaning, the objects to be joined are slid relative to each other. Thereafter, both objects to be bonded are relatively moved in a direction perpendicular to the bonding surface, and both objects to be bonded are bonded.

JP 2005-268766 A

  However, the joining technique using the retractable electric field plasma (hereinafter also simply referred to as “plasma”) described in Patent Document 1 is applicable when gold or copper is used as an object to be joined. This material is difficult to apply when a material such as sapphire is used as an object to be bonded.

  Here, in a bonding technique using plasma, an alternating voltage is applied to an electrode holding an object to be bonded to impart an electrical polarity (for example, negative polarity), and a specific substance having a reverse polarity (for example, argon ions). By pulling in, it is made to collide with the said specific substance joining surface, and an impurity is removed by the collision force. However, since an alternating voltage (alternating electric field) is applied to the electrode that holds the object to be bonded, the electrode may further have a reverse polarity, and if an ionized substance other than the specific substance exists, The material will also be drawn. However, since gold and copper are substances that do not react easily with other substances, even when there is another substance (for example, oxygen) different from a specific substance (for example, argon) in plasma processing, It is hard to react. Therefore, when gold or copper is used as the object to be bonded, surface activation treatment can be performed by plasma. On the other hand, in the case of a substance that easily reacts with another type of substance (for example, oxygen), it reacts not only with the specific substance (such as argon) but also with the other substance, so the surface activation treatment is appropriately performed. I can't.

  As described above, the plasma bonding technique described in Patent Document 1 has a problem that it can be applied only to limited types of objects to be bonded.

  In view of this, the present invention provides that, when surface activation treatment is performed on various types of objects to be bonded, the objects that have adhered to one object to be reattached to the other object to be bonded. It is an object to provide a bonding technique that can be prevented.

  In order to solve the above-mentioned problems, the invention of claim 1 is a bonding apparatus, wherein the bonding surfaces of both the first and second objects to be bonded are substantially parallel to each other and to each other. A state in which both the objects to be bonded are arranged so as to be shifted from each other in the first direction so that the bonding surfaces of the objects to be bonded do not overlap each other when viewed from the normal direction of the bonding surface. The ionized specific substance is accelerated by an electric field, and the specific substance is released toward the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded, respectively. First and second surface activating means for activating each of a bonding surface of one object to be bonded and a bonding surface of the second object to be bonded; and the first and second surface activating means. The two objects to be joined that have been subjected to surface activation treatment using the 1st relative movement means which moves relatively in the direction of 1, and makes the joining surface of both said to-be-joined objects oppose, and both said to-be-joined objects made into the opposing state by the said 1st relative movement means And a second relative moving means for relatively moving both the objects to be joined together to join the objects to be joined.

  According to a second aspect of the present invention, in the bonding apparatus according to the first aspect of the present invention, an ionized specific substance is applied by an electric field from the side of the facing space of the two objects to be bonded having the facing state toward the facing space. A third surface activation means for activating the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded by accelerating and releasing the specific substance; The second relative moving means joins both the objects to be joined after the surface activation process by the third surface activating means is performed.

  According to a third aspect of the present invention, in the joining apparatus according to the second aspect of the present invention, the second relative movement means is configured to perform the two joints in parallel with the surface activation process by the third surface activation means. The two objects to be joined are relatively moved so as to bring the objects close to each other.

  According to a fourth aspect of the present invention, there is provided a bonding apparatus according to any one of the first to third aspects, wherein the first and second surface activations are applied to the pressure in the processing space in which the objects to be bonded are arranged. Before the surface activation treatment by the means, the pressure reduction means further reduces the pressure value to a value lower than the pressure value at the time of the surface activation treatment by the first and second surface activation means.

  According to a fifth aspect of the present invention, in the bonding apparatus according to any one of the first to fourth aspects of the present invention, during the surface activation treatment by the first and second surface activation means, the first object is provided. The bonded surface of the bonded object and the bonded surface of the second bonded object are arranged so as to be shifted from each other in the first direction and face each other, and include the bonded surface of the first bonded object. The flat surface and the flat surface including the bonding surface of the second object to be bonded are arranged close to each other.

  According to a sixth aspect of the present invention, in the joining apparatus according to the fifth aspect of the invention, the surface of the first object to be joined is included during the surface activation treatment by the first and second surface activating means. The distance between the plane and the plane including the bonding surface of the second workpiece is 20 millimeters or less.

  According to a seventh aspect of the present invention, in the bonding apparatus according to any one of the first to sixth aspects, the first and second surface activation means are ionized after accelerating the ionized specific substance with an electric field. It is characterized by having at least one of ion beam irradiation means for emitting the ionized material as it is and atomic beam irradiation means for neutralizing and discharging the ionized specific substance after accelerating it with an electric field.

  The invention according to claim 8 is a joining method, wherein a) the joining surfaces of both of the first and second objects to be joined are arranged substantially parallel to each other and opposite to each other. In addition, in the state where both the objects to be bonded are arranged so as to be shifted from each other in the first direction so that the bonding surfaces of the objects to be bonded do not overlap each other when viewed from the normal direction of the bonding surface, By accelerating the substance with an electric field and releasing the specific substance toward the bonding surface of the first bonded object and the bonding surface of the second bonded object, A step of activating each of the bonding surface and the bonding surface of the second object to be bonded; and b) after the step a), both the first object to be bonded and the second object to be bonded. The bonded surfaces of both objects to be bonded are moved relative to each other in the first direction. Causes opposing to, characterized in that it comprises a step of bonding the two objects to be bonded to the normal direction to move relatively to the two objects to be bonded.

  According to a ninth aspect of the present invention, in the joining method according to the eighth aspect of the invention, the step b) comprises the steps of b-1) the step a), and the first and second objects to be joined. And a step of relatively moving the objects to be bonded in the first direction so as to oppose the bonding surfaces of the objects to be bonded, and b-2) a state in which the bonding surfaces of the objects to be bonded are opposed to each other. Then, the ionized specific substance is accelerated by an electric field from the side of the opposing space of the both objects to be opposed to the opposing space to release the specific substance, thereby the bonding surfaces of the both objects to be bonded. A step of activating, and b-3) after the step b-2), a step of joining the two objects to be joined.

  A tenth aspect of the present invention is the joining method according to the ninth aspect of the present invention, wherein the step b-2) includes the step b-2-1) performing the surface activation process on the both objects to be bonded, A step of relatively moving both the objects to be bonded so as to reduce a distance between the objects to be bonded.

  The invention of claim 11 is the joining method according to any one of claims 8 to 10, wherein both the step a) and the step b) are performed in the same joining apparatus. And

  A twelfth aspect of the present invention is the bonding method according to the eleventh aspect of the present invention, in which c) the processing space in which the first object and the second object are arranged before the step a). The method further includes a step of reducing the pressure to a value lower than the pressure value of the processing space in the step a).

  A thirteenth aspect of the present invention is the bonding method according to any one of the eighth to twelfth aspects, wherein in the step a), the bonding surface of the first bonded object and the second bonded object. The bonding surface of the first object to be bonded and a plane including the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded to each other. It is characterized in that it is arranged close to the plane containing it.

  A fourteenth aspect of the present invention is a semiconductor device, which is a semiconductor device produced by bonding by the bonding method according to any of the eighth to thirteenth aspects.

  According to the first to thirteenth aspects of the present invention, the surface activation treatment for both objects to be bonded is performed in a state in which both objects to be bonded are shifted from each other in the first direction. It is possible to prevent the adhered matter that has adhered to the object to be bonded again from adhering to the other object to be bonded. In particular, various types of objects to be joined can be favorably joined.

  In addition, according to the invention described in claim 14, it is possible to obtain a semiconductor device that is formed by being satisfactorily bonded with a small amount of impurities.

  In particular, according to the second aspect of the present invention, deposits adhered after the surface activation treatment by the first and second surface activation means are reduced by the surface activation treatment by the third surface activation means. Therefore, it is possible to join the objects to be joined more satisfactorily. Similarly, according to the ninth aspect of the present invention, the objects to be joined can be further satisfactorily bonded by reducing the deposits reattached after the movement in step a).

  In particular, according to the inventions according to claim 3 and claim 10, since the opportunity of reattachment is minimized by surface activating the objects to be bonded until immediately before bonding, the objects to be bonded are bonded more satisfactorily. can do.

  In particular, according to the inventions of claims 4 and 11, unnecessary floating matters can be reduced by increasing the degree of vacuum in advance.

It is a longitudinal cross-sectional view which shows the whole structure of a joining apparatus. It is a cross-sectional view of a joining apparatus. It is sectional drawing which shows an II cross section. It is sectional drawing which shows the II-II cross section. It is sectional drawing which shows an III-III cross section. It is a figure which shows the structure etc. of a position recognition part. It is a figure which shows the operation | movement in a joining apparatus. It is a figure which shows the operation | movement in a joining apparatus. It is a figure which shows the operation | movement in a joining apparatus. It is a figure which shows the operation | movement in a joining apparatus. It is a figure which shows the operation | movement in a joining apparatus. It is a figure which shows the operation | movement in a joining apparatus. It is a figure which shows the operation | movement in a joining apparatus. It is a figure which shows a pressure change. In the schematic diagram showing the principle of surface activation treatment It is a schematic diagram which shows the principle of ion beam irradiation. It is a schematic diagram which shows the principle of atomic beam irradiation. It is a figure which shows the surface activation process using plasma. It is a figure which shows the operation | movement which concerns on a modification. It is a figure which shows the joining apparatus which concerns on a modification. It is a figure which shows the operation | movement which concerns on a modification. It is a figure which shows the operation | movement which concerns on a modification. It is a figure which shows the surface activation process which concerns on a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. Device>
1 and 2 are views showing a joining device 1 according to the present invention. FIG. 1 is a longitudinal sectional view of the joining apparatus 1, and FIG. 2 is a transverse sectional view of the joining apparatus 1. In each figure, directions and the like are shown using an XYZ orthogonal coordinate system for convenience.

  This bonding apparatus 1 activates the bonding surface of the object to be bonded 91 and the bonding surface of the object to be bonded 92 with an atomic beam or the like in a chamber (vacuum chamber) 2 under reduced pressure, and both the objects to be bonded 91 and 92 are activated. Is a device for joining. According to this apparatus 1, it is possible to perform surface activation processing on the bonding surfaces of both objects to be bonded 91 and 92 and to perform solid-phase bonding of both objects to be bonded 91 and 92. Note that various materials (for example, a semiconductor wafer) are used as the objects to be bonded 91 and 92.

  The bonding apparatus 1 includes a vacuum chamber 2 which is a processing space for both the objects to be bonded 91 and 92, and a load lock chamber 3 connected to the vacuum chamber 2. The vacuum chamber 2 is connected to a vacuum pump 5 via an exhaust pipe 6 and an exhaust valve 7. The vacuum chamber 2 is put into a vacuum state by reducing (reducing pressure) the pressure in the vacuum chamber 2 in accordance with the suction operation of the vacuum pump 5. Further, the exhaust valve 7 can adjust the degree of vacuum in the vacuum chamber 2 by the opening / closing operation and the exhaust flow rate adjusting operation.

  Both objects 91 and 92 are held in the load lock chamber 3 by the clamping chuck 4 c at the tip of the introduction rod 4 and then moved into the vacuum chamber 2. Specifically, the upper article 92 is held at the tip of the introduction rod 4, moved in the X direction to the position PG <b> 2 immediately below the head 22, and then held by the head 22. Similarly, the lower workpiece 91 is moved to the position PG <b> 1 toward the stage 12 in the X direction while being held at the tip of the introduction rod 4, and is held by the stage 12.

  Both the head 22 and the stage 12 are installed in the vacuum chamber 2. Further, the head 22 is heated by the heater 24, and the temperature of the workpiece 92 held by the head 22 can be adjusted. Similarly, the stage 12 is heated by a heater 12 h (not shown) built in the stage 12, and the temperature of the workpiece 91 on the stage 12 can be adjusted.

  The head 22 is moved (translationally moved) in the X direction and the Y direction by the alignment table 23, and is rotated in the θ direction (rotation direction about the Z axis) by the rotation drive mechanism 25. The head 22 is driven by the alignment table 23 and the rotation drive mechanism 25 based on a position detection result by a position recognition unit 28 described later, and alignment operations in the X direction, the Y direction, and the θ direction are executed.

  The head 22 is moved (lifted / lowered) in the Z direction by the Z-axis lifting / lowering drive mechanism 26. The Z-axis raising / lowering drive mechanism 26 can control the applied pressure at the time of joining based on a signal detected by a pressure detection sensor (not shown).

  The stage 12 can be moved (translated) in the X direction by the slide moving mechanism 14. The stage 12 moves in the X direction between a standby position (near position PG1) near the beam irradiation unit 11 and a bonding position just below the head 22 (near position PG2). The slide moving mechanism 14 has a highly accurate position detector (linear scale), and the stage 12 is positioned with high accuracy.

  Moreover, the joining apparatus 1 includes position recognition units 18 and 28 that recognize the positions of the workpieces 91 and 92. The position recognizing units 18 and 28 have imaging units (cameras) 18b and 28b, respectively, that acquire optical images related to the objects to be joined as image data. Further, both the objects to be bonded 91 and 92 are each provided with a position identification mark (hereinafter also simply referred to as a mark). For example, two position identification marks are provided on one workpiece 91, and two position identification marks are provided on the other workpiece 92. Each mark preferably has a specific shape. However, the present invention is not limited to this, and a portion of the orientation flat of the wafer or a circuit pattern formed on the wafer may be used as a position identification mark.

  The positioning operation of both the workpieces 91 and 92 is executed by recognizing the positions of the marks attached to both the workpieces 91 and 92 by the position recognition unit (camera or the like).

  For example, the position recognition unit 18 acquires an optical image of the workpiece 91 existing at the position PG1 as image data. Specifically, light emitted from the light source 18a disposed above the outside of the vacuum chamber 2 passes through the window portion 2a of the vacuum chamber 2 and reaches the object to be bonded 91 (position PG1) to be reflected. . And the light reflected by the to-be-joined object 91 permeate | transmits the window part 2a of the vacuum chamber 2, and advances again, and reaches | attains the imaging part 18b. In this way, the position recognizing unit 18 acquires an optical image related to the workpiece 91 as image data. Then, the position recognition unit 18 extracts a mark based on the image data, recognizes the position of the mark, and eventually recognizes the position of the workpiece 91.

  Similarly, the position recognition unit 28 acquires an optical image of the object 92 present at the position PG2 as image data. Specifically, the light emitted from the light source 28a disposed below the vacuum chamber 2 passes through the window 2b of the vacuum chamber 2 and reaches the object 92 (position PG2) to be reflected. . Then, the light reflected by the object to be bonded 92 (specifically, a part thereof) travels again through the window 2b of the vacuum chamber 2 and reaches the imaging unit 28b. In this way, the position recognizing unit 28 acquires an optical image related to the workpiece 92 as image data. Further, the position recognition unit 28 extracts a mark based on the image data, recognizes the position of the mark, and consequently recognizes the position of the workpiece 92.

  Further, as will be described later, in this bonding apparatus 1, the stage 91 moves in the X direction, whereby the article 91 is moved to the position PG2, and the objects 91 and 92 are opposed to each other (FIG. 10). Transition to Reference). As shown in FIG. 6, the position recognizing unit 28 can also acquire an optical image related to both the objects to be bonded 91 and 92 as image data in a state where the objects to be bonded 91 and 92 are opposed to each other. Specifically, the light emitted from the light source 28a disposed below the vacuum chamber 2 passes through the window portion 2b of the vacuum chamber 2 and is bonded to both objects 91 and 92 (specifically, part thereof). Is transmitted through the window 2b of the vacuum chamber 2 again, and reaches the imaging unit 28b. The position recognizing unit 28 acquires, as image data, the optical images (images related to the reflected light) regarding both the objects 91 and 92 acquired in this way, and recognizes the position of the mark based on the image data. In addition, as the light source 28a, the light (for example, infrared light) which permeate | transmits both the to-be-joined objects 91 and 92, the stage 12, etc. should just be used.

  In this embodiment, as shown in FIG. 6, the position recognition unit 28 also has other light sources 28c and 28d. The position recognizing unit 28 recognizes the positions of the objects to be bonded 91 and 92 using image data relating to the transmitted light from the light sources 28c and 28d in a state where the objects to be bonded 91 and 92 face each other. Is also possible. Specifically, the light emitted from the light sources 28c and 28d disposed on the outer side of the vacuum chamber 2 is transmitted through the windows 2c and 2d of the vacuum chamber 2, and then reflected by the mirrors 28e and 28f. The direction of travel is changed and proceeds downward. The light further passes through both of the objects to be joined 91 and 92 (specifically, a part thereof), and then passes through the window portion 2b to reach the imaging unit 28b. The position recognizing unit 28 acquires, as image data, the optical images (images related to transmitted light) relating to the both objects 91 and 92 acquired in this way, and recognizes the position of the mark based on the image data.

  As described above, the joining apparatus 1 includes two types of an imaging system using reflected light (including the light source 28a and the imaging unit 28b) and an imaging system using transmitted light (including the light sources 28c and 28d and the imaging unit 28b). An imaging system is provided. The joining apparatus 1 can recognize the position of each mark by appropriately switching between these two types of imaging systems according to the situation.

  The positions of the workpieces 91 and 92 are recognized by the position recognition units 18 and 28 as described above. Then, based on the recognized position information, the head 22 is driven in the X direction, the Y direction, and / or the θ direction by the alignment table 23 and the rotation drive mechanism 25, so And the alignment operation is performed. For example, by moving the workpieces 91 and 92 slightly so that two marks attached to the workpiece 91 and two marks attached to the workpiece 92 overlap, 92 can be precisely positioned.

  The bonding apparatus 1 includes three beam irradiation units 11, 21, and 31. In the bonding apparatus 1, the surface activation process is executed using these three beam irradiation units 11, 21, and 31. As shown in FIG. 1, the beam irradiation units 11 and 21 are provided on the side wall surface on the back side (+ Y side) of the vacuum chamber 2, and the beam irradiation unit 31 is on the right side (+ X side) of the vacuum chamber 2. It is provided on the side wall surface (see also FIG. 2). Each of the beam irradiation units 11, 21, 31 irradiates a specific material beam toward a corresponding position in the vacuum chamber 2.

  More specifically, as shown in FIGS. 1 and 2, the beam irradiation unit 11 is disposed near the position PG1 on the relatively left side (−X side) in the vacuum chamber 2, and the beam irradiation unit 21 is a vacuum. It is disposed near the position PG2 on the relatively right side (+ X side) in the chamber 2.

  As shown in the cross-sectional view of FIG. 3, the beam irradiator 11 is installed facing obliquely downward at a position near the upper side of the + Y side wall surface of the vacuum chamber 2. Thereby, the beam irradiation part 11 irradiates a beam from diagonally upward with respect to the bonding surface of the said to-be-joined object 91, when the to-be-joined object 91 hold | maintained at the stage 12 exists in position PG1. The beam irradiation direction by the beam irradiation unit 11 is a direction parallel to a plane (YZ plane) perpendicular to the X axis. 3 is a cross-sectional view taken along the line II of FIG.

  As shown also in the cross-sectional view of FIG. 4, the beam irradiation unit 21 is installed facing obliquely upward at a position closer to the lower side of the + Y side wall surface of the vacuum chamber 2. Thereby, the beam irradiation part 21 irradiates a beam from diagonally downward with respect to the joining surface of the said to-be-joined object 92, when the to-be-joined object 92 hold | maintained at the head 22 exists in position PG2. The beam irradiation direction by the beam irradiation unit 21 is also a direction parallel to a plane (YZ plane) perpendicular to the X axis. 4 is a cross-sectional view taken along the line II-II in FIG.

  As shown in the cross-sectional view of FIG. 5, the beam irradiation unit 31 is installed in parallel to the horizontal plane on the + X side wall surface of the vacuum chamber 2. As a result, the beam irradiation unit 31 is configured such that both the workpiece 91 held by the stage 12 and the workpiece 92 held by the head 22 are arranged opposite to each other at the position PG <b> 2. A beam is emitted from the side of the facing space SP (see FIG. 11) toward the facing space SP. The beam irradiation direction by the beam irradiation unit 31 is a direction parallel to the X axis. 5 is a cross-sectional view taken along the line III-III in FIG.

  In this bonding apparatus 1, in a slide arrangement state (see FIG. 8) as will be described later, a specific substance (for example, argon) is released using the beam irradiation units 11 and 21, whereby both of the objects 91 and 92 are bonded. A surface activation process for activating the bonding surface is performed. Then, the joining apparatus 1 brings both the objects to be joined 91 and 92 subjected to the surface activation process into a close-to-opposed state (FIG. 10), and then brings them close to each other to join the objects to be joined 91 and 92 (FIG. 10). 12 and FIG. 13).

  Moreover, in this embodiment, after making both the to-be-joined objects 91 and 92 close to each other, a specific substance (for example, argon) is further emitted by using the beam irradiation unit 31, thereby both the to-be-joined objects 91 and 92. A surface activation process for activating the bonding surface is also performed (FIG. 11).

  Here, the beam irradiation units 11, 21, 31 accelerate the ionized specific substance (here, argon) by an electric field and release the specific substance toward the bonding surfaces of both the objects to be bonded 91, 92, The bonding surfaces of both workpieces 91 and 92 are activated.

  In this embodiment, an atomic beam irradiation device is used as the beam irradiation units 11 and 21, and an ion beam irradiation device is used as the beam irradiation unit 31.

  FIG. 15 is a schematic diagram showing the principle of the surface activation treatment. FIG. 16 is a schematic diagram showing the principle of ion beam irradiation, and FIG. 17 is a schematic diagram showing the principle of atomic beam irradiation.

  As shown in FIG. 15, in this surface activation treatment, a specific substance (for example, argon) is caused to collide with the bonding surface of the object to be bonded, thereby removing the deposit 99 on the bonding surface, and the object to be bonded (for example, 91). ), Dangling bonds (indicated by short line segments in FIG. 15), which are dangling bonds of surface atoms, are exposed. Then, after such a state is formed on the bonding surfaces of the two objects to be bonded 91 and 92, the bonding surfaces of the objects to be bonded 91 are brought into contact with each other to bond the dangling bonds. As a result, the objects to be bonded 91 and 92 are bonded at the atomic level. According to this, a very strong joined state can be realized.

  As a technique for causing a specific substance to collide with the bonding surface in this way, for example, there are an ion beam irradiation technique and an atomic beam irradiation technique.

  As shown in FIG. 16, in ion beam irradiation, a specific ionized substance (such as argon) is accelerated by an electric field E and then released while being ionized. And the said specific substance heads to a to-be-joined object with an ion state. Note that argon or the like in an ionic state is electrically neutralized by being combined with electric charges before reaching the surface of the object to be bonded.

  On the other hand, as shown in FIG. 17, in the atomic beam irradiation, an ionized specific substance (such as argon) is accelerated by the electric field E and then immediately combined with the electric charge supplied in the beam irradiation section, and its electrical characteristics. Is neutralized. And the specific substance electrically neutralized goes to a to-be-joined object at high speed.

  As described above, the timing of electrical neutralization differs between the ion beam and the atom beam, but they are common in that the ionized specific substance (such as argon) is accelerated by the electric field E. And it is common also in the point that the surface activation process as shown in FIG. 15 is performed when the accelerated specific substance collides with a joining surface at high speed.

  In this embodiment, surface activation processing or the like is performed using such beam irradiation. According to this, compared with the surface activation process by the above-mentioned plasma cleaning, it can be applied to a wider variety of types of objects to be bonded. Hereinafter, the principle will be described.

  FIG. 18 is a diagram for explaining the surface activation process using plasma cleaning. As shown in FIG. 18, in the surface activation process using plasma cleaning, electrical polarity (for example, negative polarity) is imparted to the bonding surface of the object to be processed (bonded object). Then, a specific substance (for example, positive polarity argon) having a polarity opposite to the polarity of the bonding surface is drawn toward the bonding surface by a Coulomb force and collides with the bonding surface. Removal is performed. At this time, if another ionized substance (for example, oxygen having positive polarity) other than the specific substance (such as argon) is present, that substance is also drawn. That is, not only the specific substance (such as argon) but also other substances (for example, oxygen having positive polarity) collide with the surface of the object to be bonded. Further, since an alternating voltage (alternating electric field) is applied to the electrode that holds the object to be bonded, the bonding surface of the electrode and the object to be bonded may have a reverse polarity (for example, positive polarity). Therefore, another substance (for example, oxygen having negative polarity) having a reverse polarity of the reverse polarity also collides with the surface of the object to be bonded.

  Here, gold and copper are difficult to react with other substances even when other substances (for example, oxygen) different from the specific substances (for example, argon) in the plasma treatment are present. Therefore, when gold or copper is used as the object to be bonded, the surface activation treatment can be performed relatively well with the plasma of the specific substance.

  On the other hand, when the object to be joined is a substance that easily reacts with a substance other than the specific substance (for example, oxygen), the object to be joined reacts with not only the specific substance (such as argon) but also the other substance. . For this reason, it is not possible to appropriately perform the surface activation process for the object to be bonded.

  In contrast, in this embodiment, an atomic beam and an ion beam are used. In these beams, as described above, an ionized specific substance (such as argon) is accelerated by an electric field and emitted toward the surface of the object to be bonded. Therefore, it is possible to selectively irradiate the bonding surface of the object to be bonded with a desired specific substance (for example, argon) instead of a substance inappropriate for generating dangling bonds (for example, oxygen). In other words, a desired specific substance can be supplied abundantly (in a large amount) onto the bonding surface while suppressing supply of an inappropriate substance.

  Therefore, according to this embodiment, even when a substance that easily reacts with another type of substance (such as oxygen) (a substance that easily oxidizes) is used as the object to be bonded, the surface of the object to be bonded to the bonding surface The activation process can be performed satisfactorily. That is, it is possible to satisfactorily execute the surface activation treatment of various substances. For example, even when a metal such as Al (aluminum) that is easily oxidized, silicon, a compound semiconductor (for example, GaS (gallium arsenide)), SiO2 (silicon dioxide), sapphire, or the like is used as an object to be bonded, the surface is excellent. It can be activated and joined. Further, the present invention can be applied not only to the case of joining the same type of both objects to be joined, but also to the case of joining both kinds of objects to be joined. In particular, when both the objects to be bonded are different materials, warpage and cracking are likely to occur due to the difference in thermal expansion between the both objects to be bonded, and therefore it is preferable to bond both the objects to be bonded at a low temperature. Therefore, direct bonding by dangling bonds as described above is very suitable for bonding different materials. Various semiconductor devices can be generated (manufactured) by bonding the various objects to be bonded 91 and 92.

<2. Operation>
Next, the joining operation in the joining apparatus 1 will be described with reference to the schematic diagrams of FIGS. FIG. 7 to FIG. 13 are diagrams sequentially showing each time-series process in the joining operation (joining method). 7 to 13, the stage 12 and the head 22 are not shown for convenience.

  FIG. 7 shows a state in which the workpieces 91 and 92 are introduced into the vacuum chamber 2 using the introduction rod 4 (FIG. 1) or the like. This introduction operation is performed under reduced pressure. In FIG. 7, immediately after the introduction, the upper workpiece 92 is held by the head 22 at the position PG2, and the lower workpiece 91 is held by the stage 12 at the position PG1. .

After that, as shown in FIG. 14, in the period TM0, the bonding apparatus 1 further performs a pressure reducing operation by the vacuum pump 5 to reduce the pressure in the vacuum chamber 2 to the pressure value PR0, so that the high vacuum state or the ultra high vacuum is obtained. Put it in a state. For example, vacuuming is performed to about 10 ⁻¹⁰ Torr to ^{10 −6} Torr. Thereby, unnecessary floating matters (impurities and the like) in the vacuum chamber 2 can be reduced. As shown in FIG. 14, the pressure value PR0 in this period TM0 is lower than the pressure value PR1 (for example, 10 ⁻⁴ Torr) in the period TM1 accompanied by beam irradiation (FIG. 8) described below. That is, the degree of vacuum in the period TM0 is higher than the degree of vacuum in the period TM1. In other words, the degree of vacuum in the vacuum chamber 2 is increased in advance in the period TM0 prior to the period TM1. Note that the decompression process in the period TM0 is a process executed before the beam irradiation (FIG. 8), and is also referred to as a “background decompression process”.

  Next, as shown in FIG. 8, the bonding apparatus 1 executes a surface activation process (hereinafter also referred to as a first surface activation process) F <b> 1 using the beam irradiation units 11 and 21.

  In the first surface activation treatment F1, the objects to be bonded 91 and 92 are arranged as follows. That is, the bonding surfaces of the workpieces 91 and 92 are arranged substantially parallel to each other and opposite to each other. Specifically, the bonding surface of the relatively lower workpiece 91 is arranged substantially parallel to the XY plane and upward, and the bonding surface of the relatively upper workpiece 92 is arranged substantially parallel and downward to the XY plane. Be placed. In other words, the objects to be joined 91 and 92 are arranged in a direction facing each other. However, both the objects to be joined 91 and 92 do not have an opposing state. Specifically, when viewed from the normal direction (Z direction) of the bonding surfaces of the objects to be bonded 91 and 92, both the objects to be bonded 91 and 92 are provided so that the bonding surfaces of the objects to be bonded 91 and 92 do not overlap each other. 92 are displaced from each other in the X direction (direction perpendicular to the Z direction). Such an arrangement state is also referred to as a “slide arrangement state” because both the objects 91 and 92 are slid relative to the opposed state.

  Then, beam irradiation (in this case, atomic beam irradiation) is performed by the beam irradiation units 11 and 21. Specifically, the bonding surface of the workpiece 91 is activated by the beam irradiation by the beam irradiation unit 11, and the bonding surface of the workpiece 92 is activated by the beam irradiation by the beam irradiation unit 21. Further, the beam irradiation by the beam irradiation units 11 and 21 is executed simultaneously in parallel.

  Here, with respect to the objects to be bonded 91 and 92, in the vicinity of the corresponding positions PG1 and PG2, respectively, a plane perpendicular to the arrangement direction (X direction) of the objects to be bonded 91 and 92 (parallel to the YZ plane). Beam irradiation is performed along a plane.

  Specifically, as shown in FIG. 3, the irradiation port of the beam irradiation unit 11 is to be joined from a relatively upper position on the + Y side to a relatively lower position on the −Y side in the vicinity of the position PG1. It is inclined with respect to the bonding surface of the object 91 at a predetermined inclination angle (for example, 45 degrees). Then, the beam irradiation unit 11 performs beam irradiation on the workpiece 91 from obliquely above.

  Further, as shown in FIG. 4, the irradiation port of the beam irradiation unit 21 is located near the position PG2 from the relatively lower position on the + Y side toward the relatively upper position on the −Y side. It is arranged to be inclined at a predetermined inclination angle (for example, 30 degrees) with respect to the bonding surface. Then, the beam irradiation unit 21 performs beam irradiation on the workpiece 92 from obliquely below.

  When the first surface activation process F1 as shown in FIG. 8 is completed (see FIG. 9), the stage 12 and the workpiece 91 are moved in the X direction (+ X by the slide moving mechanism 14 as shown in FIG. Moved to the side). In this way, both the objects 91 and 92 subjected to the surface activation process by the beam irradiation by the beam irradiation units 11 and 21 are relatively moved in the X direction. Then, after the movement operation is completed, both the objects to be bonded 91 and 92 have a state in which the bonding surfaces face each other (opposing state).

  Here, a rough position measurement operation is performed in the state of FIG. 9 (that is, before the movement), the movement operation of FIG. 10 is performed based on the position measurement operation, and a more accurate positioning operation ( Fine alignment operation) is executed. Specifically, first, after the execution of the first surface activation process F1, each position is measured in a state where the workpiece 91 is present at the position PG1 and the workpiece 92 is present at the position PG2. Keep it. Then, both the objects to be bonded 91 and 92 are slid to move both the objects to be bonded 91 and 92 to the proximity facing state (FIG. 10). After the movement, the position is measured using one or both of the reflected light imaging system and the transmitted light imaging system as described above, and a fine position adjustment operation (fine alignment) is performed based on the measurement result. Operation). According to this, it is possible to adjust the positions of the workpieces 91 and 92 very accurately.

  Next, as shown in FIG. 11, a second surface activation process F2 is further performed.

  In the second surface activation treatment F2, the ionized specific substance is accelerated by an electric field from the side of the facing space of both the objects to be bonded 91 and 92 having the facing state toward the facing space to This is a process of activating the bonding surfaces of both the objects to be bonded 91 and 92 by discharging. Specifically, the bonding surfaces of both objects 91 and 92 are activated by beam irradiation by the beam irradiation unit 31. Here, a case where an ion beam is irradiated by the beam irradiation unit 31 is illustrated.

  Thereafter, as shown in FIG. 12, after the second surface activation process F <b> 2 is completed, the objects to be bonded 91 and 92 are brought closer to each other. And as shown in FIG. 13, both the to-be-joined objects 91 and 92 are joined. Thereby, both the to-be-joined objects 91 and 92 are joined in a good state.

  In this embodiment, the operation as described above is executed.

  Here, when the surface activation treatment as shown in FIG. 8 is performed, the bonding surface is activated. Then, both the objects to be bonded 91 and 92 are satisfactorily bonded by sliding the both objects to be bonded 91 and 92 in the X direction after the surface activation treatment and further bringing them into the Z direction. In particular, as shown in FIG. 8, since both the objects to be bonded 91 and 92 are arranged so as to be shifted from each other in the X direction, even if the object adhered to one of the objects to be bonded rebounds. The possibility of scattering toward the other object to be bonded is reduced. Therefore, it is possible to prevent the deposit that has adhered to one workpiece to be reattached to the other workpiece.

  In particular, since surface activation processing using beam irradiation of a specific substance (here, atomic beam irradiation) is executed, various types of objects to be bonded are compared with the case where surface activation processing using plasma is executed. Can be bonded satisfactorily. Specifically, in the above-described embodiment, since an irradiation method is adopted in which only a specific substance is ionized and accelerated, and remains in an ion or neutralized and collides with an object to be joined in an atomic state, other than the specific substance. It is possible to prevent re-deposition of these substances.

  As the specific substance, for example, argon that does not react with other substances is preferably used. In addition, since argon has a large molecular weight, it is particularly suitable for surface activation treatment by separating the surface molecules of the object to be bonded by collision and exposing the bonds (producing dangling bonds). And it is possible to implement | achieve a favorable joining state by joining both the to-be-joined surfaces in which such a dangling bond was produced | generated appropriately.

  During the surface activation process using the beam irradiation units 11 and 21 as described above (FIG. 8), the plane PL1 including the bonding surface of the article 91 and the plane PL2 including the bonding surface of the article 92 are joined. Are preferably arranged close to each other. According to this, even if the deposit adhered to one of the objects to be bonded rebounds, the possibility of scattering toward the other object to be bonded further decreases. Therefore, it is possible to more reliably prevent the adhered matter that has adhered to one of the objects to be bonded from reattaching to the other object to be bonded.

  More specifically, the distance D1 (see FIG. 8) between the plane PL1 including the bonding surface of the workpiece 91 and the plane PL2 including the bonding surface of the workpiece 92 is preferably 20 millimeters or less.

  In the apparatus according to the above-described prior art in which the objects to be bonded are bonded after the surface activation treatment by plasma cleaning is performed on both the objects to be bonded, the both objects to be bonded 91 and 92 facing each other are usually provided. They are arranged at least 30 mm apart.

  On the other hand, when the distance D1 between the planes PL1 and PL2 is 20 millimeters or less, the first surface activation process F1 is executed in a closer state. Therefore, it is possible to more reliably prevent the adhered matter that has adhered to one of the objects to be bonded from reattaching to the other object to be bonded.

  Further, when the distance D1 is relatively large, misalignment may occur when the head is lowered due to the inclination of the Z axis or the like. On the other hand, by setting the distance between the two planes PL1, PL2 to 20 millimeters or less, it is possible to suppress the positional deviation when the head is lowered and to improve the alignment accuracy.

  As described above, the distance D1 is preferably small.

  The distance D1 is preferably even smaller, for example, 5 μm or less. According to this, it is possible to more reliably prevent the adhered matter that has adhered to one of the objects to be bonded again from adhering to the other object to be bonded.

  In this embodiment, in the first surface activation treatment F1, as shown in FIGS. 3, 4, and 8, a plane perpendicular to the arrangement direction (X direction) of the objects to be bonded 91, 92 ( Beam irradiation is performed obliquely from above and obliquely downward along a plane parallel to the YZ plane. Therefore, the substance removed from one of the objects to be bonded is scattered around the Y direction and the Z direction, and hardly scattered in the X direction where the other object to be bonded exists. According to this, it is possible to more reliably prevent the adhered matter that has adhered to one of the objects to be bonded again from adhering to the other object to be bonded.

  Note that, in the first surface activation process F1, if beam irradiation is performed on the object to be bonded from the side, it is difficult to perform a uniform process on the object to be bonded. In particular, the first surface activation treatment F1 preferably involves beam irradiation with a relatively large output. In such a situation, surface activation is performed between a portion near the beam irradiation port and a portion away from the beam irradiation port. It is difficult to make the degree of the conversion process comparable. On the other hand, in the above-described embodiment, beam irradiation is performed obliquely with respect to both the workpieces 91 and 92. Therefore, it is relatively easy to perform a uniform surface activation process on the object to be bonded. As a result, even when an object to be bonded having a relatively large bonding surface is to be processed, good bonding can be realized. For example, it is possible to satisfactorily perform bonding not in units of chips but in units of substrates (semiconductor wafers). Furthermore, it is possible to satisfactorily bond a larger substrate.

  In this embodiment, the second surface activation process F2 (FIG. 11) is performed after the first surface activation process F1 (FIG. 8) is completed and the movement operation to the facing state is performed. Is done. That is, the surface activation process for both the workpieces 91 and 92 is performed again after the movement period. And the to-be-joined object 92 is joined after that. Therefore, even if an unnecessary substance is reattached to the bonding surfaces of the objects to be bonded 91 and 92 in the transfer period after the surface activation process F1 (FIG. 10), the surface activation process F1. Deposits and the like attached after the end of the step can be further removed by surface activation processing by the beam irradiation unit 31. In short, the surface activation process by the beam irradiation unit 31 is performed immediately before bonding, and the period from the end of the surface activation process to the bonding time is shortened, so that bonding can be performed in a state in which deposits are suppressed. it can. Therefore, it is possible to join the workpieces 91 and 92 in a very good state.

  Moreover, according to this embodiment, by performing the surface activation process in two times of the first surface activation process F1 and the second surface activation process F2, both the objects to be bonded 91 are obtained. , 92 can be suppressed.

  For example, suppose a case where a treatment for a predetermined time T10 (for example, about 10 minutes) is performed in order to obtain the same effect by only one surface activation treatment. In this case, the temperatures of the objects to be bonded 91 and 92 are increased to, for example, a relatively high temperature (for example, about 120 ° C.).

  On the other hand, if the surface activation process is performed in two steps as in the above-described embodiment, it is possible to suppress the temperature rise of both objects 91 and 92. For example, it is possible to suppress the temperature to about 100 ° C. in the first time T11 (for example, 8 minutes) and to about 80 ° C. in the second time T11 (for example, 2 minutes).

  In this embodiment, an atomic beam is used in the first surface activation process F1, and an ion beam is used in the second surface activation process F2. Here, the energy by the ion beam is smaller than the energy by the atomic beam. Therefore, in particular, it is possible to suppress an increase in temperature of both objects 91 and 92 immediately before bonding, and more specifically, an increase in temperature of both objects 91 and 92 after fine alignment (FIG. 10). Therefore, it is possible to suppress deformation and the like due to the temperature rise of both objects to be joined 91 and 92.

  If a relatively large temperature rise occurs, the substrate may be warped or cracked. Such warpage induces misalignment at the time of joining. Even if warpage does not occur, for example, when both the objects 91 and 92 are of different kinds of materials, both the objects to be bonded are caused by the difference in thermal expansion coefficient between the objects to be bonded 91 and 92. Misalignment may occur between the objects 91 and 92. On the other hand, such a situation can be avoided by suppressing the temperature rise of both the workpieces 91 and 92. In particular, it is possible to prevent warpage and cracking due to a difference in thermal expansion between different materials, and it is possible to improve alignment accuracy, which is alignment accuracy between objects to be joined.

  Moreover, in the said embodiment, the beam irradiation parts 11, 21, and 31 are provided in the same joining apparatus 1 (specifically in the same vacuum chamber 2). In other words, in this embodiment, the first surface activation process F1, the second surface activation process F2, and the bonding process are performed in the same apparatus. Therefore, it is not necessary to move both the objects 91 and 92 to another apparatus, and the second surface activation treatment F2 is performed in a relatively short period after the completion of the first surface activation treatment F1. It is possible to join both the workpieces 91 and 92 by execution. For example, compared with a case where a processing chamber for performing the surface activation process F1 and a bonding chamber for performing the bonding process are provided separately and the workpiece is transferred from the processing chamber to the bonding chamber using a transfer robot or the like, The time from the end of the first surface activation process to the completion of bonding is shortened. Therefore, it is possible to perform good bonding while suppressing reattachment.

  In particular, after the first surface activation treatment F1 is completed, both the objects to be bonded can be opposed to each other by sliding both objects in the same bonding apparatus 1, so that the objects can be bonded. The time until joining can be further shortened. Therefore, it is possible to further suppress the reattachment and perform good bonding.

  Moreover, in the said embodiment, the beam irradiation parts 11, 21, and 31 are each being fixed to the joining apparatus 1. FIG. The power supply to the beam irradiation units 11, 21, 31 can be performed from outside the vacuum chamber 2. Therefore, it is not necessary to provide a power supply path in the vacuum chamber 2. On the other hand, in the technique described in Patent Document 1, it is necessary to supply power to a movable stage or the like for plasma processing, so that the electrical configuration is relatively complicated. As described above, according to the embodiment, the electrical configuration can be easily constructed as compared with the technique described in Patent Document 1.

  In the above embodiment, since the background decompression process (FIG. 14) is executed in advance during the period TM0, unnecessary floating matters can be reduced in advance. Therefore, both the objects to be bonded 91 and 92 can be bonded very well. In particular, when the background decompression process is performed, the probability that a relatively large suspended matter or impurity exists in the second surface activation process F2 is very low. In the second surface activation treatment F2, impurities that can be removed with a relatively small impact force (for example, moisture or hydrocarbon (reaction product of water and carbon)) become the main suspended matter. . Therefore, the irradiation energy in the second surface activation treatment F2 is reduced, and the adhering material is removed by the beam irradiation of the relatively small energy by the beam irradiation unit 31 while suppressing the temperature rise of the both objects 91 and 92. It is possible. Thus, the background decompression process is a particularly effective technique for the two-stage process including the first surface activation process F1 and the second surface activation process F2 as described above.

  In addition, the atomic beam irradiation treatment and the ion beam irradiation treatment can be performed in a relatively high vacuum state (relatively low pressure) as compared with the plasma treatment. Therefore, by executing a combination of the background decompression process and the atomic beam irradiation process (and / or the ion beam irradiation process), after reducing unnecessary floating substances and the like in advance, a state in which the floating substances and the like are small is obtained. The surface activation treatment and the bonding treatment can be performed very well while maintaining.

  Furthermore, the idea related to the combination of the beam irradiation process and the background decompression process can be applied to the continuous process of a plurality of sets of both objects to be bonded as compared to the idea of combining the plasma process and the background process. The Specifically, in a technique in which a surface activation process for a certain object to be bonded and a background decompression process for the next both objects to be bonded are successively performed, a beam irradiation process is employed as the surface activation process. In this case, since the surface activation process is performed in a relatively high vacuum state as compared with the case where the plasma treatment is adopted as the surface activation process, the pressure during the surface activation process and the back The difference (pressure difference) from the pressure during ground decompression is relatively small. Therefore, after the surface activation treatment for both of the objects to be bonded, the time for evacuating again to realize a predetermined pressure state (high vacuum state or the like) in the background decompression process for the next both objects to be bonded is obtained. Can be shortened. Thus, the technique combining the background decompression process and the beam irradiation process is suitable for continuous processing of a plurality of sets of both objects to be bonded, that is, mass production.

  In addition, the treatment according to the above embodiment is suitable for bonding of the above-described substances (such as aluminum) other than gold (and copper), but can also be suitably used for bonding gold (and copper). It is.

<3. Modified example>
Although the embodiments of the present invention have been described above, the present invention is not limited to the contents described above.

  For example, in the above-described embodiment, during the second surface activation process F2, the objects to be bonded 91, 92 are not moved, and after the second surface activation process F2 is completed, the objects to be bonded 91, Although the case where the operation | movement which makes 92 approach mutually is started (FIGS. 11-13) was illustrated, it is not limited to this.

  Specifically, as shown in FIG. 19, both the objects to be bonded 91 and 92 are brought close to each other while performing the second surface activation process F <b> 2 by the beam irradiation unit 31. May be joined. In other words, in parallel to the second surface activation process F2 by the beam irradiation unit 31, the objects to be bonded 91 and 92 are relatively moved so that the objects to be bonded 91 and 92 are close to each other. May be. According to this, the surface activation process is continued until the time when the bonding is completed or the time immediately before the time when the bonding is completed. For this reason, the opportunity for the deposits to re-adhere is minimized, so that the workpieces 91 and 92 can be joined in a better state. In particular, it is preferable that the surface activation treatment is continued until the completion of bonding.

  Further, in such a modification, the beam irradiation unit 31 may be further modified to move in the Z direction in accordance with the relative movement in the Z direction of both the workpieces 91 and 92.

  Specifically, as shown in FIG. 20, in the bonding apparatus 1, a drive unit 33 that drives the beam irradiation unit 31 in the Z direction is provided. Then, as shown in FIGS. 21 and 22, when the second surface activation process F2 and the approaching operation of the objects to be bonded 91 and 92 are executed in parallel, the irradiation port of the beam irradiation unit 31 is used. The irradiation port and both the objects to be bonded 91, 92 are relatively moved so that there is a central position CT between the objects to be bonded 91, 92.

  More specifically, for example, immediately before the movement in the Z direction (see FIG. 19), the irradiation port of the beam irradiation unit 31 is arranged at the center position between the objects to be bonded 91 and 92, and then the head 22 starts to descend. Accordingly, the beam irradiation unit 31 may be lowered at half the lowering speed of the head 22. At this time, the stage 12 remains stopped. According to this, when the head 22 and the beam irradiation unit 31 are lowered, the irradiation port of the beam irradiation unit 31 always exists at the center position CT between the objects to be bonded 91 and 92 (see FIG. 21). . Therefore, the beam from the beam irradiation unit 31 can be evenly applied to both the workpieces 91 and 92.

  In the above embodiment, the case where the beam irradiation units 11 and 21 irradiate the atomic beam and the beam irradiation unit 31 irradiates the ion beam is exemplified, but the present invention is not limited to this. For example, all of the beam irradiation units 11, 21 and 31 may irradiate an ion beam. Or, conversely, all of the beam irradiation units 11, 21, 31 may irradiate an atomic beam. In other words, the first surface activation treatment F1 and the second surface activation treatment F2 may be treatments that irradiate the same type of beam.

  Particularly in such a case, the beam irradiation time (specific substance release time) by the beam irradiation unit 31 is preferably shorter than the beam irradiation time by the beam irradiation units 11 and 21. In other words, the beam irradiation time in the second surface activation treatment F2 is preferably shorter than the beam irradiation time in the first surface activation treatment F1. For example, the beam irradiation time T3 of the beam irradiation unit 31 may be set shorter than the beam irradiation times T1 and T2 of the beam irradiation units 11 and 21. For example, when the values T1 and T2 are each 8 minutes, the value T3 may be set to 2 minutes. According to this, the temperature rise of both the to-be-joined objects 91 and 92 immediately before joining, especially the temperature rise of both the to-be-joined objects 91 and 92 after fine alignment (FIG. 10) can be suppressed. Therefore, it is possible to suppress deformation and the like due to the temperature rise of both objects to be joined 91 and 92.

  Similarly, the beam irradiation output (specific substance emission intensity) by the beam irradiation unit 31 is preferably smaller than the beam irradiation output by the beam irradiation units 11 and 21. In other words, the beam irradiation output in the second surface activation process F2 is preferably smaller than the beam irradiation output in the first surface activation process F1. Specifically, the beam irradiation output voltage V3 of the beam irradiation unit 31 may be set smaller than the beam irradiation output voltages V1 and V2 of the beam irradiation units 11 and 21. For example, when the values V1 and V2 are both 80 V (volts), the value V3 may be set to 20 V (volts). According to this, especially the temperature rise of both the to-be-joined objects 91 and 92 just before joining, more specifically, the temperature rise of the to-be-joined objects 91 and 92 after fine alignment can be suppressed. Therefore, it is possible to suppress deformation and the like due to the temperature rise of both objects to be joined 91 and 92.

  Moreover, in the said embodiment, the beam irradiation by the beam irradiation parts 11 and 21 is along a plane (plane parallel to a YZ plane) perpendicular | vertical to the arrangement direction (X direction) of both to-be-joined objects 91 and 92, respectively. Although the case where it was performed was illustrated, it is not limited to this. For example, as shown in FIG. 23, beam irradiation is executed obliquely from above and obliquely downward along a plane (plane parallel to the XZ plane) parallel to the arrangement direction (X direction) of the workpieces 91 and 92. You may make it do. Even in this case, by bringing the bonding surfaces of the objects to be bonded 91 and 92 close to each other, it is possible to more reliably prevent the adhering material adhering to one object to be reattached to the other object to be bonded. Is possible.

  However, it is more preferable that the beam irradiation is performed in the manner as in the above embodiment (see FIGS. 3, 4 and 8). According to the above-described embodiment, the other object to be bonded does not exist in the beam irradiation direction. Therefore, compared to the embodiment illustrated in FIG. It is possible to more reliably prevent reattachment to an object.

  Further, in the above-described embodiment, during the surface activation process using the beam irradiation units 11 and 21, the bonding surfaces of the objects to be bonded 91 and 92 face each other in a state of being shifted from each other in the X direction. Although the case where it arrange | positions closely was illustrated, this invention is not limited to this. For example, both the objects to be bonded 91 and 92 may be arranged in a state where the bonding surface of the object to be bonded 92 exists below the bonding surface of the object to be bonded 91. Specifically, the bonding surface of the workpiece 92 may be arranged with a predetermined distance (for example, several millimeters) shifted downward in the Z direction (−Z direction) from the bonding surface of the workpiece 91. . According to this, similarly to the above, it is possible to avoid the problem that the adhering material adhering to one object to be bonded reattaches to the other object to be bonded.

  In this case, after the surface activation treatment F1 using the beam irradiation units 11 and 21, both the objects to be bonded 91 and 92 are moved relatively in both the X direction and the Z direction, thereby What is necessary is just to join both the to-be-joined objects 91 and 92 after making the joining surface of the to-be-joined objects 91 and 92 oppose. Specifically, the workpieces 91 and 92 may be made to face each other by moving the workpiece 91 in the + X direction and moving (raising) the workpiece 92 in the + Z direction. However, from the viewpoint of operation simplification or the like, it is preferable to cause both the objects to be joined 91 and 92 to transition to the facing state without accompanying movement in the Z direction.

  Moreover, in the said embodiment, although the case where the to-be-joined object 91 was slid in the + X direction and the both to-be-joined objects 91 and 92 were made into the opposing state was illustrated, it is not limited to this. For example, conversely, by moving the workpiece 92 in the X direction, the workpieces 91 and 92 are moved relative to each other in the X direction so that the workpieces 91 and 92 face each other. May be.

  Moreover, in the said embodiment, although the to-be-joined object 92 was moved to -Z direction and the case where both the to-be-joined objects 91 and 92 were joined was illustrated, it is not limited to this. For example, the workpiece 91 may be moved in the + Z direction to move both the workpieces 91 and 92 relatively in the Z direction.

  Moreover, in the said embodiment, although the case where the 2nd surface activation process F2 was further performed after the 1st surface activation process F1 was illustrated, it is not limited to this. For example, the objects to be bonded 91 and 92 may be bonded without executing the second surface activation process F2. Specifically, after the first surface activation process F1 is performed, both the objects to be bonded 91 and 92 are slid in the X direction to face each other. And you may make it join both the to-be-joined objects 91 and 92 of an opposing state relatively moving to a Z direction, without accompanying the 2nd surface activation process F2. Also by such a modification, both the to-be-joined objects 91 and 92 can be joined favorably. Moreover, although the process which concerns on the said modification is suitable also for joining of the above substances (aluminum etc.) other than gold (and copper), it can be used suitably also for joining of gold (and copper). It is.

  For example, the process according to the modified example using ion beam irradiation or the like as the first surface activation process F1 is better bonding than the surface activation process using the plasma process according to the comparative example described below. It is possible to realize the state. Here, in the comparative example, after the first surface activation process F1 is performed using “plasma”, both the objects to be bonded 91 and 92 are slid in the X direction so as to face each other. This is a technique of joining both the workpieces 91 and 92 facing each other in the Z direction without the activation process F2. For example, even if a void having a relatively large area (a gap generated between both objects to be bonded) occurs in the bonding result of the process according to the comparative example (bonding temperature = 25 ° C.), the process according to the modified example (bonding) In the result of bonding by (temperature = 25 ° C.), the void area can be made relatively small.

  In order to reduce the voids, it is preferable that the temperature of both objects to be bonded 91 and 92 is higher than room temperature (25 ° C.). For example, both the objects to be bonded are bonded in a state where the temperatures of the objects to be bonded 91 and 92 are raised to an appropriate temperature (also referred to as void disappearance temperature) TE using the heaters 12h and 24 (FIG. 1). Thus, the void can be almost eliminated. The void extinction temperature TE according to the comparative example is a relatively high temperature TE2 (for example, 150 ° C.), whereas the void extinction temperature TE according to the modification is a relatively low temperature TE1 (for example, 80 ° C.) (<TE2). It is. That is, in the case where such heat treatment is performed, according to the modification, it is possible to substantially eliminate voids at a relatively low temperature TE1. In other words, the temperature TE1 for relatively eliminating the voids may be a relatively low temperature TE1. Therefore, it is possible to realize a good joined state while suppressing or avoiding the occurrence of warpage or the like in the article to be joined.

  In the above embodiment, argon (Ar) is exemplified as the specific substance released by beam irradiation. However, the specific substance is not limited to this, and other substances such as krypton (Kr) or xenon (Xe) may be used. Good.

DESCRIPTION OF SYMBOLS 1 Joining apparatus 2 Vacuum chamber 5 Vacuum pump 6 Exhaust pipe 7 Exhaust valve 11, 21, 31 Beam irradiation part 12 Stage 14 Slide movement mechanism 18, 28 Position recognition part 22 Head 23 Alignment table 25 Rotation drive mechanism 26 Z-axis raising / lowering drive mechanism 28e, 28f Mirror 33 Drive unit 91, 92 Bonded object 99 Adhered substance

Claims (14)

The bonding surfaces of both the objects to be bonded of the first object to be bonded and the second object to be bonded are arranged substantially in parallel with each other and opposite to each other, and the both surfaces are viewed from the normal direction of the bonding surface. In a state where both the objects to be bonded are arranged so as to be shifted from each other in the first direction so that the bonding surfaces of the objects to be bonded do not overlap, the ionized specific substance is accelerated by an electric field to bond the first objects to be bonded. By releasing the specific substance toward each of the surface and the bonding surface of the second object to be bonded, the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded First and second surface activation means for activating each;
The two objects to be bonded that have been subjected to the surface activation process using the first and second surface activating means are moved relative to each other in the first direction, and the bonding surfaces of the two objects to be bonded are moved. First relative movement means to be opposed;
A second relative position for moving both the objects to be bonded together so as to bring the objects to be bonded brought close to each other by the first relative moving means to join the objects to be bonded; Transportation means;
A joining apparatus comprising: The joining apparatus according to claim 1,
By accelerating an ionized specific substance with an electric field from the side of the opposing space of the objects to be bonded having the opposing state toward the opposing space, the specific substance is released. A third surface activation means for activating the bonding surface of the object and the bonding surface of the second object to be bonded;
Further comprising
The second relative moving means joins the objects to be joined after the surface activation treatment by the third surface activating means is performed. The joining apparatus according to claim 2,
The second relative moving means relatively moves the objects to be bonded so that the objects to be bonded approach each other in parallel with the surface activation processing by the third surface activating means. A joining apparatus characterized by. In the joining apparatus in any one of Claims 1 thru | or 3,
The surface activation by the first and second surface activation means is performed before the surface activation treatment by the first and second surface activation means by applying the pressure in the treatment space in which both the objects to be bonded are arranged. Pressure reducing means for reducing the pressure value to a value lower than the pressure value during processing,
The joining apparatus further comprising: In the joining apparatus in any one of Claims 1 thru | or 4,
During the surface activation treatment by the first and second surface activation means, the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded are in the first direction. The plane including the bonding surface of the first object to be bonded and the plane including the bonding surface of the second object to be bonded are arranged close to each other and arranged to face each other. Characteristic joining device. The joining apparatus according to claim 5,
During the surface activation process by the first and second surface activation means, a distance between a plane including the bonding surface of the first object to be bonded and a plane including the bonding surface of the second object to be bonded. Is 20 mm or less. In the joining apparatus in any one of Claims 1 thru | or 6,
The first and second surface activation means include:
An ion beam irradiation means for accelerating an ionized specific substance with an electric field and then releasing the ionized substance as it is,
An atomic beam irradiation means for neutralizing and discharging the ionized specific substance after accelerating it with an electric field;
A joining apparatus comprising at least one of the following. a) The bonding surfaces of both of the first and second objects to be bonded are arranged substantially parallel to each other and opposite to each other, and are viewed from the normal direction of the bonding surface. In a state where both the objects to be bonded are arranged so as to be shifted from each other in the first direction so that the bonding surfaces of both objects to be bonded do not overlap, the ionized specific substance is accelerated by an electric field, and the first object to be bonded is obtained. The specific surface is released toward each of the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded, whereby the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded are released. And a step of activating each of
b) After the step a), both the objects to be bonded of the first object to be bonded and the second object to be bonded are moved relative to each other in the first direction to bond the objects to be bonded. A process of facing the surfaces and moving both the objects to be bonded relative to each other in the normal direction to bond the objects to be bonded;
A bonding method comprising: The joining method according to claim 8,
Said step b)
b-1) After the step a), both the objects to be bonded of the first object to be bonded and the second object to be bonded are moved relative to each other in the first direction, and the both objects to be bonded. A step of facing the bonding surface of
b-2) With the bonding surfaces of the objects to be bonded facing each other, the ionized specific substance is accelerated by an electric field from the side of the space facing the objects to be bonded to the space facing the object. Activating the bonding surfaces of both objects to be bonded by releasing a specific substance;
b-3) After the step b-2), joining both the objects to be joined;
A bonding method comprising: The joining method according to claim 9,
The step b-2)
b-2-1) a step of relatively moving the objects to be bonded so as to reduce the distance between the objects to be bonded while performing a surface activation process on the objects to be bonded;
A bonding method comprising: In the joining method in any one of Claims 8 thru | or 10,
The step a) and the step b) are both performed in the same bonding apparatus. The joining method according to claim 11,
c) Before the step a), the pressure of the processing space in which the first and second objects are arranged is lower than the pressure value of the processing space in the step a). Process to reduce to the value,
The joining method characterized by further including. The bonding method according to any one of claims 8 to 12,
In the step a), the bonding surface of the first object to be bonded and the bonding surface of the second object to be bonded are arranged so as to be shifted from each other in the first direction and facing each other, A bonding method characterized in that a plane including a bonding surface of the first object to be bonded and a plane including a bonding surface of the second object to be bonded are arranged close to each other.   A semiconductor device formed by bonding by the bonding method according to claim 8.

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