Bonded body

Abstract

A bonded body 10 includes: a first plate 11; a second plate 12 that is of a type identical to or different from that of the first plate 11; and an amorphous layer 13 existing at a bonding interface between the first plate 11 and the second plate 12. A first plate altered layer 11a exists on the side of the first plate 11 in contact with the amorphous layer 13, and a second plate altered layer 12a exists on the side of the second plate 12 in contact with the amorphous layer 13.

Description

zygote

[0001] The present invention relates to a conjugate.

[0002] 2. Description of the Related Art Conventionally, a bonded structure in which a Si plate and a piezoelectric material plate are bonded together using a fast atom beam (FAB) has been known (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-102856

[0004] However, depending on the materials of the two plates, it may not be possible to obtain a bonded body with high bonding strength.

[0005] The present invention has been made to solve such problems, and a main object of the present invention is to obtain a bonded body with high bonding strength.

[0006] [1] The bonded structure of the present invention comprises: a first plate; a second plate of the same or different type as the first plate; an amorphous layer present at the bonding interface between the first plate and the second plate; a first-plate altered layer present on the side of the first plate that contacts the amorphous layer; and a second-plate altered layer present on the side of the second plate that contacts the amorphous layer.

[0007] This bonded body has a relatively high bonding strength.

[0008] [2] In the bonded structure of the present invention (the bonded structure according to the above [1]), the amorphous layer may have a thickness of 0.1 nm or more.

[0009] [3] In the bonded body of the present invention (the bonded body described in [1] or [2] above), the thickness of the first plate alteration layer may be 10 nm or more, and the thickness of the second plate alteration layer may be 10 nm.

[0010] [4] In the bonded body of the present invention (the bonded body according to any one of [1] to [3] above), the first plate and the second plate may be dense bodies.

[0011] [5] In the joined body of the present invention (the joined body according to any one of [1] to [4] above), the first plate may be a plate made of a metal compound, and the second plate may be a plate made of the same or a different metal compound as the first plate. The metal compound may be one selected from metal oxides, metal nitrides, and metal carbides. At least one of the first plate and the second plate may be ceramic, and both the first plate and the second plate may be alumina ceramic.

[0012] [6] In the bonded body of the present invention (the bonded body according to any one of [1] to [5] above), the diameter of the bonded body may be 100 mm or more and 500 mm or less.

[0013] 1 is a perspective view of the bonded body 10. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1. FIG. 3 is an explanatory diagram of a polishing apparatus 20. FIG. 4 is a TEM image of the bonded body 10.

[0014] A preferred embodiment of the present invention will be described below with reference to the drawings, in which: Fig. 1 is a perspective view of a bonded body 10, and Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0015] The bonded structure 10 includes a first plate 11, a second plate 12, and an amorphous layer 13. If the first plate 11 and the second plate 12 are made of different materials, there may be one or more amorphous layers 13. The diameter of the bonded structure 10 may be, for example, 100 mm or more and 500 mm or less.

[0016] The first plate 11 is a plate made of a metal compound. The metal compound may be, for example, one selected from a metal oxide, a metal nitride, and a metal carbide. Examples of metal oxides include Al2O3. Examples of metal nitrides include AlN and Si3N4. Examples of metal carbides include SiC. The thickness of the first plate 11 is, for example, 100 μm or more and 15 mm or less. The first plate 11 may be a dense body.

[0017] The second plate 12 is a plate made of the same or different metal compound as the first plate 11. The second plate 12 may be a plate made of the same metal compound as the first plate 11 but with different properties (e.g., plasma resistance, thermal conductivity, volume resistivity, etc.). The metal compound may be, for example, one selected from metal oxides, metal nitrides, and metal carbides. Examples of metal oxides include Al2O3. Examples of metal nitrides include AlN and Si3N4. Examples of metal carbides include SiC. The thickness of the second plate 12 is, for example, 100 μm or more and 15 mm or less. The second plate 12 may be a dense body.

[0018] At least one of the first plate 11 and the second plate 12 may be made of ceramic. Alternatively, both the first plate 11 and the second plate 12 may be made of alumina ceramic. Alternatively, the first plate 11 may be made of sapphire and the second plate 12 may be made of alumina ceramic.

[0019] The amorphous layer 13 is present at the bonding interface between the first plate 11 and the second plate 12. For example, when XRD is measured, the amorphous layer 13 exhibits a broader peak than the first plate 11 or the second plate 12. In a cross-sectional enlarged image of the bonded body 10 taken by a transmission electron microscope (TEM), the amorphous layer 13 is observed as a thin band. The thickness of the amorphous layer 13 is preferably 0.1 nm or more, more preferably 0.1 nm to 30 nm, and even more preferably 1 nm to 20 nm. The thickness of the amorphous layer 13 measured by TEM observation is measured using the following procedure. On a TEM photograph (magnification: 4,000,000 times) of one field of view, the thickness of the amorphous layer 40 is measured at five locations along the bonding interface at 10 nm intervals, and the average thickness of the amorphous layer in one field of view is calculated. The thickness measurement by the TEM observation is performed equally in three fields of view, including the vicinity of the center, the vicinity of the outer periphery, and the vicinity of the center of the radius when the semiconductor manufacturing equipment member is viewed in plan view. The average value of the thickness of the amorphous layer 13 in the three fields of view is then taken as the measured value.

[0020] The first plate 11 has a first-plate-altered layer 11a on the side in contact with the amorphous layer 13. When, for example, XRD is measured, the first-plate-altered layer 11a exhibits a broader peak than the portion of the first plate 11 other than the first-plate-altered layer 11a, but a sharper peak than the amorphous layer 13. In an enlarged cross-sectional image of the bonded body 10 taken by TEM, the first-plate-altered layer 11a is observed as having a different form from the portion of the first plate 11 other than the first-plate-altered layer 11a. The thickness of the first-plate-altered layer 11a is preferably 10 nm or more, more preferably 100 nm or more and 1 μm or less, and even more preferably 100 nm or more and 600 nm or less.

[0021] The second plate 12 has a second-plate-altered layer 12a on the side in contact with the amorphous layer 13. For example, when XRD is measured, the second-plate-altered layer 12a exhibits a broader peak than the remaining portion of the second plate 12, but a sharper peak than the amorphous layer 13. In a TEM enlarged cross-sectional image of the bonded body 10, the second-plate-altered layer 12a is observed as having a different form from the remaining portion of the second plate 12. The thickness of the second-plate-altered layer 12a is preferably 10 nm or more, more preferably 100 nm or more and 1 μm or less, and even more preferably 100 nm or more and 600 nm or less. The thicknesses of the first-plate-altered layer 11a and the second-plate-altered layer 12a measured by TEM observation are measured using the following procedure. On a TEM photograph (magnification: 500,000 times) of one field of view, the thicknesses of the first plate altered layer 11a and the second plate altered layer 12a are measured at five locations 200 nm apart along the bonding interface, and the average thickness of the first plate altered layer 11a and the second plate altered layer 12a in one field of view is calculated. Similar thickness measurements by TEM observation are performed evenly on three fields of view, including near the center, near the outer periphery, and near the center of the radius when the semiconductor manufacturing equipment component is viewed in plan. The average thickness of the first plate altered layer 11a and the second plate altered layer 12a in the three fields of view is then taken as the measured value.

[0022] Next, a description will be given of an example of use of the bonded body 10. The bonded body 10 can be used as an electrostatic chuck. In this case, the first plate 11 is formed of a dense ceramic body (e.g., alumina ceramic), and an electrostatic electrode is embedded inside the first plate 11.

[0023] Next, a manufacturing example of the bonded body 10 will be described. First, the first plate 11 and the second plate 12 are manufactured. For example, the first plate 11 may be manufactured by hot-pressing and firing a molded body containing a metal compound powder (e.g., ceramic powder). In this way, the first plate 11 can be made into a dense body. The second plate 12 is manufactured in the same manner as the first plate 11. At this stage, the first plate 11 does not have a first-plate altered layer 11a. The second plate 12 also does not have a second-plate altered layer 12a.

[0024] Next, the first plate 11 is subjected to lapping using a polishing apparatus 20 shown in FIG. 3 . The polishing apparatus 20 includes a large-diameter disc-shaped polishing platen 22 equipped with a polishing pad 24, a small-diameter disc-shaped carrier 26, and a pipe 28 for supplying a slurry containing abrasive grains to the polishing pad 24. The polishing platen 22 has a shaft at the center of its underside, which is rotated by a drive motor (not shown), thereby rotating about its axis (spinning). The carrier 26 has a shaft at the center of its upper surface, which is rotated by a drive motor (not shown), thereby rotating about its axis (spinning). The carrier 26 is positioned off-center on the polishing platen 22. To polish the first plate 11 using this polishing apparatus 20, the first plate 11 is attached to the underside of the carrier 26, and the first plate 11 is sandwiched between the polishing pad 24 of the polishing platen 22 and the carrier 26. A slurry containing abrasive grains is then supplied to the polishing pad 24 from the pipe 28. This supplies slurry between the first plate 11 and the polishing pad 24 of the polishing table 22. In this state, the first plate 11 is pressed against the polishing pad 24 by the carrier 26, while the polishing table 22 and the carrier 26 are rotated to perform polishing. The polishing conditions are set so that the surface roughness (arithmetic mean roughness) Ra of the underside of the first plate 11 is 1 nm or less. For example, the polishing conditions are set such that a slurry with an average abrasive grain size of 1 μm or less is used, and the polishing table 22 and the carrier 26 are rotated at a speed of 20 to 200 rpm. As a result, the surface roughness Ra of the polished surface of the first plate 11 is 1 nm or less. Furthermore, a first-plate altered layer 11a is formed on the polished surface side of the first plate 11. The surface roughness (arithmetic mean roughness) Ra of the polished surface is measured using a non-contact surface roughness meter in accordance with ISO 25178.

[0025] The second plate 12 is also subjected to lapping using the polishing device 20 in the same manner as the first plate 11. As a result, the surface roughness Ra of the polished surface of the second plate 12 becomes 1 nm or less. In addition, a second-plate altered layer 12a is formed on the polished surface side of the second plate 12.

[0026] Next, the polished surface of the first plate 11 is irradiated with a fast atom beam (FAB) under high vacuum, and the polished surface of the second plate 12 is also irradiated with the FAB under high vacuum. The FAB conditions are set, for example, at a voltage of 0.5 to 2 kV, a current of 50 to 200 mA, and an irradiation time of 30 to 300 seconds. This removes oxides and adsorbed molecules from the polished surfaces of the first plate 11 and the second plate 12, causing the polished surfaces to become amorphous (activated). The two plates 11 and 12 are then superimposed so that the polished surface of the first plate 11 faces the polished surface of the second plate 12, and are bonded while being pressed. The load during pressing is set, for example, to 0.1 to 50 kN. This results in a bonded body 10 with high bonding strength.

[0027] The bonded body 10 described above has a relatively high bond strength between the plates 11 and 12. In particular, even if the first plate 11 and the second plate 12 are both ceramic (e.g., alumina ceramic), the bonded body 10 has a good bond strength. Because the bonded body 10 has a good bond strength, it can be used for reworking, in porous parts, and the like.

[0028] It goes without saying that the present invention is not limited to the above-described embodiment, and can be embodied in various forms as long as they fall within the technical scope of the present invention.

[0029] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0030] (Example) Dense alumina ceramic plates with a diameter of 100 mm, a thickness of 600 μm, and a purity of 99.9% or higher were prepared as the first plate 11 and the second plate 12. Next, using a polishing device 20, the first plate 11 was subjected to lapping using small abrasive grains (average abrasive grain size 0.1 μm) so that one side of the first plate 11 had a surface roughness Ra of 0.5 nm or less. Similarly to the first plate 11, one side of the second plate 12a was also subjected to lapping so that the surface roughness Ra of the second plate 12a was 0.5 nm or less. Next, the polished surface of the first plate 11 was irradiated with an Ar beam under high vacuum as FAB, and the polished surface of the second plate 12 was also irradiated with an Ar beam under high vacuum as FAB. The two plates 11 and 12 were then overlapped so that the polished surface of the first plate 11 and the polished surface of the second plate 12 faced each other, and were bonded under pressure. This resulted in a bonded body 10. A cross-section near the bonding interface of the bonded body 10 was magnified using a TEM to obtain an image. The resulting image is shown in FIG. 4 . FIG. 4(A) is an image magnified 500,000 times, and FIG. 4(B) is an image magnified 4,000,000 times. The cross-sectional TEM observation using the above method revealed the presence of an amorphous layer 13 (a thin white band-like portion) measuring 4.5 nm in thickness at the bonding interface between the first plate 11 and the second plate 12. Furthermore, a first-plate altered layer 11a was observed on the side of the first plate 11 that contacted the amorphous layer 13, and a second-plate altered layer 12a was also observed on the side of the second plate 12 that contacted the amorphous layer 13. The measured thicknesses of the altered layers were confirmed using the cross-sectional TEM observation using the above method, and altered layers measuring 300 nm in thickness were formed on both the first and second plates 11 and 12. The bond strength of the resulting bonded body 10 was measured by a crack opening method and was found to be 0.5 to 3.0 J / m 2 It was.

[0031] (Comparative Example) FAB bonding was performed in the same manner as in Example 1, except that large abrasive grains (average abrasive grain size 20 μm) were used during lapping. A degraded layer with a measured thickness exceeding 1 μm was obtained, but bonding was not possible. This is thought to be due to the roughness of the surface (surface roughness Ra of 100 nm) caused by the use of large abrasive grains.

[0032] This application claims priority from Japanese Patent Application No. 2023-077440, filed on May 9, 2023, the entire contents of which are incorporated herein by reference.

[0033] The present invention can be used for joining bodies, for example, bodies made of ceramics joined together.

[0034] 10 Bonded body, 11 First plate, 11a First plate altered layer, 12 Second plate, 12a Second plate altered layer, 13 Amorphous layer, 20 Polishing device, 22 Polishing surface plate, 24 Polishing pad, 26 Carrier, 28 Pipe.

Claims

1. A first plate; A second plate of the same type or a different type as the first plate; an amorphous layer present at a bonding interface between the first plate and the second plate; a first plate affected layer present on a side of the first plate that contacts the amorphous layer; a second plate affected layer present on a side of the second plate that contacts the amorphous layer; Equipped with The first plate and the second plate are the same dense alumina ceramic plate. zygote.

2. The thickness of the amorphous layer is 0.1 nm or more. The joint body according to claim 1 .

3. The thickness of the first plate altered layer is 10 nm or more, and the thickness of the second plate altered layer is 10 nm or more. The bonded body according to claim 1 or 2.

4. The diameter of the joint is 100 mm or more and 500 mm or less. The bonded body according to claim 1 or 2.