joint

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

Technical Field

[0001] The present invention relates to a joined body.

Background Art

[0002] Conventionally, a joined body obtained by joining a Si plate and a piezoelectric material plate using a fast atom beam (FAB) is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, depending on the materials of the two plates, a joined body with high joining strength may not be obtained in some cases.

[0005] The present invention has been made to solve such a problem, and a main object thereof is to obtain a joined body with high joining strength.

Means for Solving the Problems

[0006] [1] The joined body of the present invention is a first plate, a second plate that is the same type as or different from the first plate, an amorphous layer present at the joining interface between the first plate and the second plate, a first plate altered layer present on the side of the first plate in contact with the amorphous layer, and a second plate altered layer present on the side of the second plate in contact with the amorphous layer.

[0007] ​This type of joint results in a relatively high joint strength.

[0008] [2] In the bonded body of the present invention (the bonded body described in [1] above), the thickness of the amorphous layer may be 0.1 nm or more.

[0009] [3] In the joint of the present invention (the joint described in [1] or [2] above), the thickness of the first plate altered layer may be 10 nm or more, and the thickness of the second plate altered layer may be 10 nm That's all. That's fine.

[0010] [4] In the joint of the present invention (the joint described in any of [1] to [3] above), the first plate and the second plate may be made of a dense material.

[0011] [5] In the joint of the present invention (the joint described in any 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 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 a ceramic, and both the first plate and the second plate may be alumina ceramics.

[0012] [6] In the joint of the present invention (the joint described in any of [1] to [5] above), the diameter of the joint may be 100 mm or more and 500 mm or less. [Brief explanation of the drawing]

[0013] [Figure 1] Perspective view of the joint 10. [Figure 2] Cross-sectional view AA in Figure 1. [Figure 3] Diagram illustrating the polishing device 20. [Figure 4] TEM image of the fused body 10. [Modes for carrying out the invention]

[0014] Preferred embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a perspective view of the joint 10, and Figure 2 is a cross-sectional view of AA in Figure 1.

[0015] The jointed body 10 comprises 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, the amorphous layer 13 may consist of one or more layers. The diameter of the jointed body 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 selected from, for example, 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 first plate 11 is, for example, 100 μm or more and 15 mm or less. The first plate 11 may be a dense material.

[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 but different 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 selected from, for example, 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 material.

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

[0019] The amorphous layer 13 is present at the bonding interface between the first plate 11 and the second plate 12. For the amorphous layer 13, for example, when measured by XRD, a broader peak appears compared to the first plate 11 and the second plate 12. In an enlarged cross-sectional image of the bonded body 10 obtained 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 measured value of the thickness of the amorphous layer 13 by TEM observation is determined by the following procedure. On a TEM photograph (magnification: 4,000,000 times) of one field of view, the amorphous layer is measured at intervals of 10 nm along the bonding interface 13 The thickness is measured at 5 points, and the average value of the thickness of the amorphous layer in one field of view is obtained. The same thickness measurement by TEM observation is performed on 3 fields of view without bias, including the vicinity of the center, the vicinity of the outer periphery, and the vicinity of the radial center when the member for a semiconductor manufacturing apparatus is viewed in plan. Then, the average value of the thickness of the amorphous layer 13 in the 3 fields of view is 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. For the first plate altered layer 11a, for example, when measured by XRD, a peak that is broader than the portion of the first plate 11 other than the first plate altered layer 11a but sharper than that of the amorphous layer 13 appears. In an enlarged cross-sectional image of the bonded body 10 obtained by TEM, the first plate altered layer 11a is observed as a form different 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 to 1 μm, and even more preferably 100 nm to 600 nm.

[0021] The second plate 12 has a second plate alteration layer 12a on the side in contact with the amorphous layer 13. When XRD is measured, for example, the second plate alteration layer 12a shows a broad peak compared to the parts of the second plate 12 other than the second plate alteration layer 12a, but a sharp peak compared to the amorphous layer 13. In a magnified cross-sectional image of the joint 10 taken by TEM, the second plate alteration layer 12a is observed as having a different morphology from the parts of the second plate 12 other than the second plate alteration layer 12a. The thickness of the second plate alteration layer 12a is preferably 10 nm or more, more preferably 100 nm to 1 μm, and even more preferably 100 nm to 600 nm. The thickness of the first plate alteration layer 11a and the second plate alteration layer 12a is measured by the following procedure. On a single-field TEM image (magnification: 500,000x), the thickness of the first plate altered layer 11a and the second plate altered layer 12a is 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 that field of view is calculated. Similar TEM observations are performed on three fields of view, including the area near the center, the outer edge, and the center of the radius when the semiconductor manufacturing equipment component is viewed in plan view, without bias. 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, an example of the use of the joint 10 will be described. The joint 10 can be used as an electrostatic chuck. In this case, the first plate 11 is formed from a dense ceramic material (e.g., alumina ceramic), and electrostatic electrodes are embedded inside the first plate 11.

[0023] Next, an example of manufacturing the joined 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-press firing a molded body containing 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 the first plate altered layer 11a. The second plate 12 also does not have the second plate altered layer 12a.

[0024] Next, the first plate 11 is lapped using the polishing device 20 shown in Figure 3. The polishing device 20 comprises 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 slurry containing abrasive particles to the polishing pad 24. The polishing platen 22 has a shaft in the center of its lower surface, and rotates axially (on its own axis) when the shaft is driven by a drive motor (not shown). The carrier 26 has a shaft in the center of its upper surface, and rotates axially (on its own axis) when the shaft is driven by a drive motor (not shown). The carrier 26 is positioned offset from the center of the polishing platen 22. To polish the first plate 11 with this polishing device 20, the first plate 11 is mounted on the lower surface 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. Then, slurry containing abrasive particles is supplied to the polishing pad 24 from the pipe 28. Then, slurry is supplied between the first plate 11 and the polishing pad 24 of the polishing platen 22. In this state, polishing is performed by rotating the polishing platen 22 and carrier 26 while pressing the first plate 11 against the polishing pad 24 with the carrier 26. Polishing conditions are set so that the surface roughness (arithmetic mean roughness) Ra of the lower surface of the first plate 11 is 1 nm or less. Polishing conditions include, for example, using a slurry with an average abrasive particle size of 1 μm or less, and setting the rotation speed of the polishing platen 22 and carrier 26 to 20 to 200 rpm. As a result, the surface roughness Ra of the polished surface of the first plate 11 becomes 1 nm or less. In addition, 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 with a non-contact surface roughness meter in accordance with the ISO 25178 standard.

[0025] The second plate 12 is also subjected to lapping using the polishing device 20, similar to 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 atomic beam (FAB) under high vacuum, and the polished surface of the second plate 12 is also irradiated with FAB under high vacuum. The FAB conditions are set, for example, to 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). Then, the two plates 11 and 12 are stacked on top of each other so that the polished surfaces of the first plate 11 and the second plate 12 face each other, and joined under pressure. The load during pressing is set, for example, to 0.1 to 50 kN. This results in a joined body 10 with high bonding strength.

[0027] As described above, the bonded structure 10 provides relatively high bonding strength between the two plates 11 and 12. In particular, even if the first plate 11 and the second plate 12 are both ceramic (for example, both alumina ceramics), a bonded structure 10 with good bonding strength can be obtained. As a result of obtaining a bonded structure 10 with good bonding strength, it can be used for rework purposes, as well as in porous areas.

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

[0029] Examples of the present invention will be described below. Note that the following examples do not limit the present invention in any way.

[0030] (Examples) 1 ) First plate 11 and second plate 12 were prepared as dense alumina ceramic plates with a diameter of 100 mm, a thickness of 600 μm, and a purity of 99.9% or higher. Next, using a polishing apparatus 20, the first plate 11 was lapped with small abrasive grains (average abrasive grain size 0.1 μm) so that the surface roughness Ra of one side of the first plate 11 was 0.5 nm or less. The second plate 12 was also lapped in the same manner as the first plate 11. 2 One surface was lapped to a surface roughness Ra of 0.5 nm or less. Next, the polished surface of the first plate 11 was irradiated with an Ar beam as a FAB under high vacuum, and the polished surface of the second plate 12 was also irradiated with an Ar beam as a FAB under high vacuum. Then, the two plates 11 and 12 were stacked on top of each other so that the polished surfaces of the first plate 11 and the second plate 12 faced each other, and joined under pressure. This obtained a joined body 10. A cross-section near the joining interface of the joined body 10 was magnified with a TEM and an image was obtained. The image is shown in Figure 4. Figure 4(A) is an image magnified 500,000 times, and Figure 4(B) is an image magnified 4,000,000 times. From the cross-sectional TEM observation using the above method, an amorphous layer 13 (a thin white band-like portion) with a measured thickness of 4.5 nm was found to exist at the joining interface between the first plate 11 and the second plate 12. Furthermore, a first plate alteration layer 11a was observed on the side of the first plate 11 in contact with the amorphous layer 13, and a second plate alteration layer 12a was observed on the side of the second plate 12 in contact with the amorphous layer 13. Cross-sectional TEM observation using the above method confirmed the measured thickness of the alteration layers, revealing that alteration layers with a thickness of 300 nm were formed on both the first and second plates 11 and 12. The joint strength of the resulting joint 10 was measured using the crack opening method and was found to be 0.5~3.0 J / m². 2 That was the case.

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

[0032] This application is based on Japanese Patent Application No. 2023-077440, filed on 9 May 2023, and the entire contents of that application are incorporated herein by reference. [Industrial applicability]

[0033] The present invention can be used for joints, such as joints between ceramics. [Explanation of Symbols]

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

Claims

1. A first plate having a thickness of 100 μm or more and 15 mm or less, A second plate of the same type as the first plate, with a thickness of 100 μm or more and 15 mm or less, An amorphous layer present at the bonding interface between the first plate and the second plate, The first plate alteration layer located on the side of the first plate that is in contact with the amorphous layer, The altered second plate layer located on the side of the second plate that is in contact with the amorphous layer, Equipped with, The first plate and the second plate are the same dense alumina ceramic plate. The thickness of the amorphous layer is 0.1 nm or more and 30 nm or less. The thickness of the first plate alteration layer and the thickness of the second plate alteration layer are 100 nm or more and 1 μm or less. zygote.

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

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