Ceramic Structures

Abstract

The ceramic structure comprises: a first layer having first crystalline particles; a second layer situated on top of the first layer and having second crystalline particles; and an amorphous layer situated between the first and second layers. The first and second crystalline particles each contain: one or more metallic elements selected from Al, Si, Ti, Cr, Zr, and Y; and one or more non-metallic elements selected from N, C, and B. The first and second crystalline particles are of the same compound. The amorphous layer contains both metallic and non-metallic elements.

Description

[Technical Field]

[0001] The embodiments of the invention relate to ceramic structures. [Previous Technology]

[0002] Ceramic structures having a thin film formed on a substrate by chemical vapor deposition (CVD) as described in Patent Document 1 are known. Patent Document 2 describes a film formed by chemical vapor deposition that is dense and pore-free, exhibiting high smoothness. Furthermore, Patent Document 3 describes a method that reduces the pore content to less than 3% of the area.

[0003] Prior art documents Patent document 1: Japanese Patent Application Publication No. Sho 63-40314 Patent document 2: Japanese Patent Application Publication No. Hei 7-180057 Patent document 3: Japanese Patent Application Publication No. 2020-53579 [Summary of the Invention]

[0004] One embodiment of the ceramic structure includes: a first layer having first crystal particles; a second layer situated on the first layer and having second crystal particles; and an amorphous layer situated between the first and second layers. The first and second crystal particles each contain: one or more metallic elements selected from Al, Si, Ti, Cr, Zr, and Y; and one or more non-metallic elements selected from N, C, and B. The first and second crystal particles are the same compound. The amorphous layer contains both the metallic and non-metallic elements.

Implementation Method

[0006] In the above structure, there is room for further improvement in terms of enhancing the durability of the ceramic structure.

[0007] Therefore, there is an expectation to provide ceramic structures with excellent durability.

[0008] Hereinafter, embodiments of the ceramic structure disclosed in this application will be described with reference to the accompanying drawings. It should be noted that the invention is not limited to the embodiments shown below.

[0009] <Embodiment> FIG1 is a cross-sectional view showing an example of a ceramic structure according to an embodiment. In the example shown in FIG1, the ceramic structure 1 has a first layer 10, a second layer 20, and an amorphous layer 30. The first layer 10 has first crystal particles 11. The second layer 20 has second crystal particles 21. The first crystal particles 11 and the second crystal particles 21 each contain one or more metallic elements selected from Al, Si, Ti, Cr, Zr, and Y, and one or more non-metallic elements selected from N, C, and B.

[0010] The first layer 10 may contain more than 50% of the first crystal particles 11. The first layer 10 may also contain more than 80% of the first crystal particles 11. The first layer 10 may also contain more than 90% of the first crystal particles 11.

[0011] The second layer 20 may contain more than 50% area of ​​second crystal particles 21. The second layer 20 may also contain more than 80% area of ​​second crystal particles 21. The second layer 20 may also contain more than 90% area of ​​second crystal particles 21.

[0012] Furthermore, the amount of second crystal particles 21 contained in the second layer 20 can be greater than the amount of first crystal particles 11 contained in the first layer 10. The first crystal particles 11 and the second crystal particles 21 are the same compound. The first crystal particles 11 and the second crystal particles 21 can be any one of AlN, Si3N4, SiC, TiN, TiC, ZrN, ZrB, and YN. In particular, the first crystal particles 11 can be AlN. "The same compound" means, for example, if it is AlN, then Al and N are the main components, and it can be identified as AlN by XRD. For example, Al and N may not be contained in a 1:1 ratio. The Al content can differ between the first crystal particles 11 and the second crystal particles 21.

[0013] The amorphous layer 30 is located between the first layer 10 and the second layer 20. The amorphous layer 30 contains the metallic and non-metallic elements contained in the first crystal particles 11 and the second crystal particles 21. When such a structure is present, the stress generated between the first layer 10 and the second layer 20 is mitigated, providing a ceramic structure 1 with excellent durability.

[0014] The amorphous layer 30 may contain all the metallic and non-metallic elements contained in the first crystal particle 11 and the second crystal particle 21. Alternatively, the amorphous layer 30 may not contain a portion of the metallic and non-metallic elements contained in the first crystal particle 11 and the second crystal particle 21. Furthermore, the amorphous layer 30 may contain elements different from the metallic and non-metallic elements contained in the first crystal particle 11 and the second crystal particle 21.

[0015] The amorphous layer 30 may contact the surface 101 of the first layer 10 and the second layer 20 that are opposite to each other. The amorphous layer 30 may also contact the first surface 201 of the second layer 20 that is opposite to the first layer 10.

[0016] The thickness of the amorphous layer 30 may be less than 200 nm, for example. The ceramic structure 1 may have a portion between the first layer 10 and the second layer 20 where the amorphous layer 30 is not disposed.

[0017] The thickness of the amorphous layer 30 can be measured using the following methods. For example, it can be measured using a transmission electron microscope. For example, it can be measured using a JEM-ARM200F NEOARM transmission electron microscope manufactured by JEOL Ltd. Amorphous materials do not have the precise periodicity of crystals; they are random atomic arrangements. Therefore, in the presence of an amorphous layer, a distinct diffraction spot is not observed, but rather a blurry, concentric halo pattern is observed.

[0018] The crystalline phase can be determined by the following method. Low-angle incident measurements are performed using a thin-film X-ray diffraction apparatus, the X'Pert PRO-MRD (DY1878) manufactured by PANalytical. The optical system is configured as follows: X-ray mirror (automatic insertion attenuator, 5-gauge, 0.02 rad Solar slit, 1 / 8 slit), flat collimator, tube: CuKα, X-ray: 45 kV, 40 mA, 2θ scan: 10°~100°, incident angle: 0.1°, step size: 0.02°, time: 4.0 seconds / step. For example, whether the crystal particle is AlN can also be determined based on JCPDS No. 00-025-1133.

[0019] In the example shown in Figure 1, the first layer 10 is a substrate, which may be generally circular. In the example shown in Figure 1, the second layer 20 is located on the substrate (first layer 10) and may be in contact with the substrate (first layer 10).

[0020] The matrix (first layer 10) contains, for example, ceramics such as aluminum nitride (AlN) as the main component. Alternatively, the first layer 10 may also contain, for example, alumina (Al2O3) or yttrium oxide (Y2O3). Furthermore, the first layer 10 may be a sintered body obtained by firing raw material powder. When the first layer 10 is a sintered body, the crystallinity of the first crystal particles 11 is relatively high. When such a structure is present, a ceramic structure with excellent durability can be provided.

[0021] In addition, the first crystal particle 11 and the second crystal particle 21 can also be hexagonal crystals. In the case of hexagonal crystals, the crystal exhibits anisotropy, and by utilizing this anisotropy, a ceramic structure with excellent durability can be provided.

[0022] In addition, the first crystal particle 11 and the second crystal particle 21 can also be AlN.

[0023] The second layer 20 may have a void 22 located inside the second layer 20. The void 22 may be longer in the thickness direction of the second layer 20 and blocked at both ends in the thickness direction. The void 22 may also have at least one of a first void 22a that contacts the first layer 10 at one end in the thickness direction and a second void 22b that is separated from the first layer 10 at one end. By having such a structure, for example, the residual stress inside the second layer 20 can be reduced. Therefore, delamination and cracking between the first layer 10 and the second layer 20 are difficult to occur, and the durability of the ceramic structure 1 is improved.

[0024] The void 22 may also have a longitudinally elongated shape that is longer in the thickness direction than in the width direction of the second layer 20. The void 22 may also have both ends blocked in the thickness direction of the second layer 20. That is, the void 22 may also be located between the first surface 201 of the second layer 20 opposite to the first layer 10 and the second surface 202 of the second layer 20 opposite to the first surface 201, and is not exposed as the second surface 202, which is the interface with the outside. Therefore, the second layer 20 has the desired durability even though it has void 22 inside. The void 22 is not a lattice defect, so-called nanopore, that may exist in the second crystal particles 21. The width of the void 22 may, for example, be 0.01 μm or more. The width of the void 22 may, for example, be 0.05 μm or more. The width of the void 22 may, for example, be 1 μm or less. The width of the void 22 may, for example, be 0.5 μm or less. The length of the void 22 may, for example, be 0.2 μm or more. The length of the pore 22 can be, for example, 0.5 μm or more. The length of the pore 22 can also be, for example, 5 μm or less. The length of the pore 22 can also be, for example, 1 μm or less.

[0025] The presence or absence of the gap 22 can be confirmed, for example, by observation based on an electron microscope. The area percentage occupied by the gap 22 in the second layer 20 can be, for example, 3% or more. The area percentage of the gap 22 can also be, for example, 4% or more. The area percentage of the gap 22 can be, for example, 5% or less. The determination of the area percentage occupied by the gap 22 in the second layer 20 can be performed, for example, at the center of the cross-section after mirror finishing of the cross-section of the second layer 20. The observation based on an electron microscope can be performed at a magnification of 1000x to 50000x. For example, an electron microscope can be used with a JSM7900F manufactured by Nippon Electronics and an accelerating voltage of 5.0kV. The area percentage of the gap 22 can also be calculated based on the SEM image using the image analysis software IMAGE Pro10 manufactured by MEDIA CYBERNETICS. In this case, the SEM image can also be binarized using the Ward method, and the calculation can be performed using the binarized image.

[0026] Alternatively, the gap 22 may have a first gap 22a and a second gap 22b. The first gap 22a is a gap 22 whose lower end, as one end of the second layer 20 in the thickness direction, contacts the surface 101 of the first layer 10. The second gap 22b is a gap 22 whose one end is separated from the surface 101 of the first layer 10. The second layer 20 may also have both the first gap 22a and the second gap 22b internally. The second layer 20 may also have only either the first gap 22a or the second gap 22b.

[0027] Next, the details of the second layer 20 will be further explained using Figure 2. Figure 2 is an enlarged view of region A shown in Figure 1.

[0028] The second crystal particles 21 of the second layer 20 may have columnar crystals 21a. The columnar crystals 21a may, for example, extend in a direction intersecting the surface 101 of the first layer 10. That is, the columnar crystals 21a may extend along the thickness direction of the second layer 20. The second layer 20 may have a plurality of columnar crystals 21a arranged along the surface 101 of the first layer 10. By having columnar crystals 21a in the second crystal particles 21, the thermal conductivity in the thickness direction of the second layer 20 is improved. Therefore, the temperature deviation in the thickness direction of the second layer 20 is reduced, and durability is improved.

[0029] Furthermore, regarding the width of the void 22, that is, the length of the void 22 in the direction along the surface 101 of the first layer 10, the second end 222, which is farther away from the first layer 10, is smaller than the first end 221 located in the thickness direction on the side of the first layer 10. Therefore, the void 22 is less likely to become a crack and propagate from the second end 222 towards the second surface 202. Thus, the durability of the ceramic structure 1 including the second layer 20 is improved. The void 22 may also be located between adjacent columnar crystals 21a. The void 22 may be larger or smaller than the columnar crystals 21a.

[0030] Additionally, a space 40 may be provided between the first layer 10 and the second layer 20. Here, space 40 refers to a space extending along the surface 101 of the first layer 10. More specifically, it refers to a space in cross-section where the length connecting the two ends of space 40 in the direction along surface 101 using an imaginary line segment is longer than the maximum height of space 40 in the direction intersecting surface 101. More specifically, the length connecting the two ends of space 40 in the direction along surface 101 using an imaginary line segment is at least 5 times, preferably at least 10 times, the height of space 40 in the direction intersecting surface 101.

[0031] In the second layer 20, the first portion, which is closer to the first layer 10, can have a larger porosity compared to the second portion, which is farther away from the first layer 10. This allows the thermal conductivity of the first portion to be lower than that of the second portion. Therefore, when a thermal shock is applied to the ceramic structure 1 from the second layer 20 side, abrupt changes in the temperature difference between the first layer 10 and the second layer 20 are suppressed. As a result, the durability of the ceramic structure 1 against thermal shock is improved. It should be noted that the first portion can, for example, be the region including the first surface 201 in the aforementioned SEM image, and the second portion can, for example, be the region including the second surface 202 in the aforementioned SEM image. Furthermore, the first and second portions can be partially repeated.

[0032] The amorphous layer 30 can be configured to contact both the first layer 10 and the second layer 20. The amorphous layer 30 can also be separated from either the first layer 10 or the second layer 20.

[0033] Figures 3 and 4 are cross-sectional views showing another example of the ceramic structure according to the embodiment. As shown in Figure 3, the second layer 20 may have a plurality of columnar crystals 21a inclined relative to the surface 101 of the first layer 10. Furthermore, voids 22 may be located between adjacent columnar crystals 21a. Therefore, when the leading edge of a columnar crystal 21a contacts a void 22, the residual stress of the columnar crystal 21a is reduced, thus improving the durability of the second layer 20. It should be noted that while Figure 3 illustrates a first void 22a as an example of void 22, it could also be a second void 22b.

[0034] Furthermore, as shown in FIG4, the first layer 10 may have uneven surfaces on its surface 101 opposite to the second layer 20. Additionally, the first end portion 221 of the gap 22, which is one end in the thickness direction, may be located within the recess 101b of the first layer 10. This prevents the gap 22 from extending along the surface 101 of the first layer 10 at the first end portion 221. As a result, the formation of cracks in the columnar crystals 21a adjacent to the first end portion 221 is suppressed, and the durability of the ceramic structure 1 is improved. The same applies when the gap 22 is located on the protrusion 101a of the first layer 10. It should be noted that FIG4 illustrates the first gap 22a as an example of the gap 22, but it could also be the second gap 22b. Furthermore, the gap 22 may also be located on the protrusion 101a of the first layer 10. In addition, Figure 4 illustrates an example in which multiple columnar crystals 21a extend along the thickness direction of the second layer 20, but they may also extend obliquely relative to the thickness direction of the second layer 20 in a manner corresponding to the unevenness of the surface 101 of the first layer 10.

[0035] The volume resistivity of the second layer 20 at 25°C can be greater than that of the first layer 10 at 25°C. The volume resistivity of the second layer 20 at 500°C can be greater than that of the first layer 10 at 500°C. The volume resistivity of the second layer 20 at 25°C can be 1×10¹² Ω·m or higher. The volume resistivity of the second layer 20 at 500°C can be 1×10⁵ Ω·m or higher.

[0036] The volume resistivity of the second layer 20 and the first layer 10 can be determined using the three-terminal method according to JIS C 2141:1992.

[0037] The ceramic structure 1 may have a conductive layer inside. The conductive layer may also function as a heater. In addition, the conductive layer may also have an adsorption function. The conductive layer may be, for example, a metal such as W, Mo, Ni, or Pt.

[0038] FIG5 is a cross-sectional view showing another example of the ceramic structure according to the embodiment. FIG6 is an enlarged view of region B shown in FIG5.

[0039] The second crystal particles 21 of the second layer 20 may have a dendritic structure 210. The dendritic structure 210 may have stem portions 210a and dendritic portions 210b. In the stem portion 210a, for example, the second crystal particles 21 are arranged in a direction intersecting the surface 101 of the first layer 10 (see FIG5). That is, the stem portion 210a has the second crystal particles 21 arranged in the thickness direction of the second layer 20. The stem portion 210a may also have the second crystal particles 21 arranged in a direction perpendicular to the surface 101 of the first layer 10. The stem portion 210a may also include a stem portion 210c in which the second crystal particles 21 are arranged obliquely relative to the thickness direction of the first layer 10.

[0040] The second layer 20 may also have a plurality of dry portions 210a arranged along the surface 101 of the first layer 10. By having such a structure, the thermal conductivity of the second layer 20 in the thickness direction is improved. Therefore, the temperature deviation in the thickness direction of the second layer 20 is reduced, and the durability is improved.

[0041] The second layer 20 may have a dendritic portion 210b in which second crystal particles 21 are arranged in a direction having a different crystal structure from that of the stem portion 210a. By having such a structure, for example, the residual stress inside the second layer 20 can be reduced. Therefore, delamination and cracking between the first layer 10 and the second layer 20 are difficult to occur, and the durability of the ceramic structure 1 is improved.

[0042] The second layer 20 may have a plurality of first regions 20a arranged along the surface 101 of the first layer 10 and second regions 20b located between adjacent first regions 20a. Stem-like portions 210a may be located in the first regions 20a. A plurality of branch-like portions 210b may be located in the second regions 20b.

[0043] FIG7 is a cross-sectional view showing an example of a dendritic structure. The dendritic structure 210 has a trunk portion 210a and a crystal structure different from the trunk portion 210a. As shown in FIG7, the trunk portion 210a has side surfaces 23, 24 located at both ends in the width direction intersecting the length direction.

[0044] The dendritic structure 210 can have dendritic portions 210b as a crystal structure different from the trunk portion 210a. The dendritic portion 210b can have multiple dendritic portions 210b1 located on the side 23 of the trunk portion 210a. The dendritic portion 210b can also have multiple dendritic portions 210b2 located on the side 24 of the trunk portion 210a. The dendritic structure 210 can have dendritic portions 210b in which second crystal particles 21 are arranged at an angle θ of 30° or more and 60° or less relative to the trunk portion 210a.

[0045] The dry portion 210a may be configured to contact the first surface 201 (see FIG. 5) of the second layer 20, which is opposite to the first surface 201. The dry portion 210a may also be configured to contact the second surface 202 (see FIG. 5) of the second layer 20, which is opposite to the first surface 201. Alternatively, the dry portion 210a may be configured separately from the first surface 201 and the second surface 202.

[0046] In addition, the branch-like portion 210b may contact the trunk-like portion 210a. The branch-like portion 210b may also be disposed separately from the trunk-like portion 210a.

[0047] Furthermore, as shown in FIG7, the dendritic structure 210 may have voids 25 without trunk portions 210a and dendrite portions 210b. By having such a structure, for example, the residual stress inside the second layer 20 is further reduced. Therefore, delamination and cracking between the first layer 10 and the second layer 20 are difficult to occur, and the durability of the ceramic structure 1 is improved.

[0048] It should be noted that the second layer 20 of the ceramic structure 1 can be a second crystal particle 21 and have one or both of columnar crystal 21a and dendritic structure 210.

[0049] <Method for Manufacturing Ceramic Structures> An example of a method for manufacturing ceramic structures will be described using FIG8. FIG8 is a flowchart showing an example of a method for manufacturing ceramic structures according to an embodiment.

[0050] A disk-shaped sintered body containing 90% to 99.9% by mass of AlN is prepared as the matrix (first layer 10). Furthermore, a second layer, primarily composed of AlN, is formed on the surface of this matrix in the following sequence: First, a catalyst is applied to a first gas (step S11). The first gas can be a nitrogen-containing gas, such as ammonia. The catalyst can be, for example, tungsten. For example, when the catalyst is applied to the first gas at an environment of approximately 1600°C to 2200°C, the first gas decomposes through catalysis, generating multiple active species.

[0051] Next, the active species generated in step S11 and the second gas are supplied to the first layer 10 (step S12). Trimethylaluminum can be used as the second gas, for example.

[0052] Next, a second layer 20 is formed on the first layer 10 (step S13). The first layer 10 may also be heated as needed. The temperature of the first layer 10 can be set to, for example, 420°C to 1000°C, especially a temperature exceeding 700°C but below 1000°C. The film formation time can be set to, for example, 0.5 hours to 20 hours depending on the desired thickness. The pressure during film formation (film formation pressure) can be set to 10 Pa to 100 Pa. The film formation pressure can be set to 20 Pa or less, or even 10 Pa. For example, a ceramic structure 1 with a second layer 20 having a different crystal structure on the first layer 10 and an amorphous layer 30 located between the second layer 20 and the first layer 10 is obtained based on the set temperature during film formation (film formation temperature), etc.

[0053] Example: An AlN sintered body containing 98% by mass of AlN crystals as the main phase was prepared. The AlN sintered body was processed into a first layer of 100 mm square. It should be noted that a conductive layer containing W as a metal was disposed inside the AlN sintered body. This conductive layer was formed into a heating pattern. Then, on one surface of the first layer, ammonia was used as the first gas, trimethylaluminum was used as the second gas, and tungsten was used as the catalyst to form a second layer. The film formation temperature and film formation pressure in step S13 are shown in Table 1. As one comparative example, the aforementioned AlN sintered body without the second layer was used. In addition, as another comparative example, sample No. 8 is shown as an example of film formation without the use of a catalyst.

[0054] Furthermore, the presence and shape of voids were observed using a cross-section of the second layer of the obtained ceramic structure. As a comparative example, a structure equivalent to the first and second layers was fabricated using a sintered body, and this is also recorded in Table 1. The film-forming temperature and the aforementioned measured values ​​are recorded in Table 1. It should be noted that in Table 1, columns that are empty or marked with "-" are those that were not measured or calculated.

[0055] [Table 1]

[0056] Sample No. 1 lacks an interface. Sample No. 8 has an interface but lacks an amorphous layer. Sample No. 8, lacking an amorphous layer, exhibits a lower film formation rate and poorer productivity. On the other hand, amorphous layers were confirmed in Samples No. 2 to No. 7. In Samples No. 5 to No. 7, amorphous layers with thicknesses ranging from 50 nm to 200 nm were confirmed. Samples No. 6 and No. 7, with amorphous layer thicknesses ranging from 50 nm to 200 nm, exhibit particularly excellent durability. It should be noted that Sample No. 7, with an amorphous layer thickness of 50 nm, shows the best bonding strength. Regarding the durability of the ceramic structure, the bonding strength between the first and second layers was measured, and samples with excellent bonding strength were identified as samples with excellent durability. According to the results in Table 1, the thickness of the amorphous layer is less than 200 nm, and there is a tendency for the bonding strength to be higher the thinner the layer.

[0057] It should be noted that the bonding strength is calculated based on values ​​measured using an Autograph AG-IS manufactured by Shimadzu Corporation. First, a Φ20 mm flat thread clamp was bonded to the surface of the second layer of a plate-shaped sample (20 mm × 40 mm) with a second layer using adhesive. The maximum force at which the bonded portion breaks when the flat thread clamp is lifted approximately perpendicularly to the surface of the plate-shaped sample was measured. The value obtained by dividing this maximum force by the area of ​​the bonded portion is taken as the bonding strength.

[0058] In one embodiment, (1) the ceramic structure has: a first layer having first crystal particles; a second layer located above the first layer and having second crystal particles; and an amorphous layer located between the first layer and the second layer, wherein the first crystal particles and the second crystal particles respectively contain: one or more metallic elements selected from Al, Si, Ti, Cr, Zr and Y; and one or more non-metallic elements selected from N, C and B, wherein the first crystal particles and the second crystal particles are the same compound, and the amorphous layer contains the metallic element and the non-metallic element.

[0059] In the ceramic structure of (1) above, the thickness of the amorphous layer may be less than 200 nm.

[0060] (3)In the ceramic structure of (1) or (2) above, the second layer may have a void located inside the second layer, the void being longer in the thickness direction of the second layer, and both ends of the void in the thickness direction being blocked, the void having at least one of a first void with one end in the thickness direction in contact with the first layer and a second void with one end separated from the first layer.

[0061] (4)In the ceramic structure of the above (3), the porosity of the cross section of the second layer parallel to the thickness direction may be more than 3% and less than 5%.

[0062] (5)In the ceramic structure of the above (3) or (4), the second layer may have a plurality of columnar crystals inclined relative to the surface of the first layer, and the voids are located between adjacent plurality of columnar crystals.

[0063] (6)In any of the ceramic structures in (3) to (5) above, the first layer may have uneven surfaces on the surface opposite to the second layer, and one end of the void in the thickness direction may be located in the recess of the first layer.

[0064] (7)In any of the ceramic structures in (3) to (6) above, the second end of the void, which is farther away from the first layer, is smaller in length along the direction of the surface of the first layer than the first end of the void in the thickness direction located on the side of the first layer.

[0065] (8)In any of the ceramic structures in (3) to (7) above, it is also possible that in the second layer, the first part closer to the first layer has a larger porosity than the second part farther away from the first layer than the first part.

[0066] (9) Any one of the ceramic structures in (1) to (8) above can have a conductive layer inside.

[0067] Further effects and variations can be readily derived by those skilled in the art. Therefore, the broader scope of the invention is not limited to the specific details and representative embodiments shown and described above. Thus, various changes can be made without departing from the conceptual spirit or scope of the invention as defined by the appended technical solutions and their equivalents. [Simplified Explanation of the Diagram]

[0005] FIG1 is a cross-sectional view showing an example of the ceramic structure according to the embodiment. FIG2 is an enlarged view of region A shown in FIG1. ​​FIG3 is a cross-sectional view showing another example of the ceramic structure according to the embodiment. FIG4 is a cross-sectional view showing another example of the ceramic structure according to the embodiment. FIG5 is a cross-sectional view showing another example of the ceramic structure according to the embodiment. FIG6 is an enlarged view of region B shown in FIG5. FIG7 is a cross-sectional view showing an example of a dendritic structure. FIG8 is a flowchart showing an example of a method for manufacturing the ceramic structure according to the embodiment.

Claims

1. A ceramic structure comprising: a first layer having first crystal particles; a second layer situated above the first layer and having second crystal particles; and an amorphous layer situated between the first layer and the second layer, wherein the first crystal particles and the second crystal particles each contain: one or more metallic elements selected from Al, Si, Ti, Cr, Zr, and Y; and one or more non-metallic elements selected from N, C, and B, wherein the first crystal particles and the second crystal particles are the same compound, and the amorphous layer contains the metallic element and the non-metallic element.

2. The ceramic structure as described in claim 1, wherein, The thickness of the amorphous layer is less than 200 nm.

3. The ceramic structure as described in claim 1 or 2, wherein, The second layer has a void located inside the second layer, the void being longer in the thickness direction of the second layer, and both ends of the void in the thickness direction being blocked, the void having at least one of a first void with one end in the thickness direction in contact with the first layer, and a second void with one end separated from the first layer.

4. The ceramic structure as described in claim 3, wherein, The porosity of the cross section parallel to the thickness direction of the second layer is more than 3% and less than 5%.

5. The ceramic structure as described in claim 3, wherein, The second layer has a plurality of columnar crystals inclined relative to the surface of the first layer, and the voids are located between adjacent columnar crystals.

6. The ceramic structure as described in claim 3, wherein, The first layer has an uneven surface on the surface opposite to the second layer, and one end of the gap in the thickness direction is located in the recess of the first layer.

7. The ceramic structure as described in claim 3, wherein, The second end of the void, which is farther from the first layer, is smaller in length along the surface of the first layer than the first end in the thickness direction located on the side of the first layer.

8. The ceramic structure as described in claim 3, wherein, In the second layer, the first portion closer to the first layer has a larger porosity compared to the second portion farther away from the first layer than the first portion.

9. The ceramic structure as claimed in claim 1 or 2, wherein, The ceramic structure has an internal conductive layer.

Images