JP6206613B1 - Ceramic structure and structural member for semiconductor manufacturing apparatus - Google Patents

Abstract

An object of the present invention is to provide a ceramic structure capable of suppressing variation in strength at an interposition part.
A first member including silicon and silicon carbide, a second member including silicon and silicon carbide, and interposed between the first member and the second member, and silicon and silicon carbide are provided. A ratio of the area of silicon included in the cross section of the interposition part to the area of the cross section of the interposition part is A, and the first part relative to the area of the cross section of the first member The ratio of the area of silicon included in the cross section of the member is B1, and the ratio of the area of silicon included in the cross section of the second member to the area of the cross section of the second member is B2. A, B1, and B2 satisfy at least one of 1.0 <A / B1 <1.3 and 1.0 <A / B2 <1.3. Is done.
[Selection] Figure 1

Description

  Aspects of the present invention generally relate to ceramic structures and structural members for semiconductor manufacturing equipment.

Reaction-sintered silicon carbide member (silicon-impregnated silicon carbide member) is a material having excellent specific rigidity and electrical conductivity and few pores. For this reason, the ceramic structure containing the reaction sintered silicon carbide member is used as a member for a semiconductor manufacturing apparatus. In particular, high precision, low outgas, and electrical conductivity are required in the operating part of an apparatus using an electron beam (such as an exposure apparatus or an inspection apparatus) or in a vacuum environment. For this reason, the reaction sintered silicon carbide member is suitable for these apparatuses.
Recently, the development of apparatuses for improving the performance of semiconductor devices and improving the throughput is progressing. For this reason, complex shaped products and large structures are required as members used in the apparatus. It is difficult to create a complex shape product or a large structure from a single molded body. Therefore, for example, a method is used in which a plurality of members (molded bodies) are bonded together with an adhesive containing carbon and subjected to reactive sintering. Patent Document 1 describes a method of controlling the microstructure of the joint in order to improve the reliability of the joint that joins the members.

JP 2005-22905 A

  However, residual voids or a large free silicon phase may occur in intervening portions that are interposed between members, such as joints. For example, when joining large members, voids remain and free silicon phases are likely to occur. In this case, since the structure | tissue of the member joined and the structure | tissue of a junction part differ from each other, the stable physical property may not be obtained. For example, the bonding strength at the bonding portion may vary or the bonding strength may decrease.

  The present invention has been made on the basis of recognition of such a problem, and an object thereof is to provide a ceramic structure capable of suppressing variation in strength at an interposition part.

A first invention includes a first member containing silicon and silicon carbide, a second member containing silicon and silicon carbide, and interposed between the first member and the second member, and silicon and silicon carbide. 10 observation regions having a size of 128 μm × 128 μm are set in the cross section of the interposed portion, and the area occupied by silicon in each of the 10 observation regions of the interposed portion is set. ratio is calculated and the average of the ratio of the 10 locations of the intermediate portion is a, the size of the observation region 128 .mu.m × 128 .mu.m set point 10 in the cross section of the first member, said first member 10 in each of the observation area locations, and calculate the ratio of the area occupied by the silicon, the average of the ratio of the 10 points of the first member and B1, sectional smell of the second member Ten observation regions each having a size of 128 μm × 128 μm are set, the ratio of the area occupied by Si in each of the ten observation regions of the second member is calculated, and the ten regions of the second member are Assuming that the average of the ratios is B2 , the A, the B1, and the B2 satisfy at least one of 1.0 <A / B1 <1.3 and 1.0 <A / B2 <1.3. The standard deviation of the ratio at the ten locations of the interposition part is C, the standard deviation of the ratio at the ten locations of the first member is D1, and the standard of the ratio at the ten locations of the second member When the deviation and D2, the C, the D1 and the D2 are 1.3 <C / D1 <3.3, and 1.3 <a Succoth satisfy at least one of C / D2 <3.3 Characteristic ceramic It is a concrete body.

  According to this ceramic structure, the segregation of silicon and the porosity of the interposition part are reduced, and variation in strength can be suppressed. It is considered that the residual stress is reduced by reducing the difference between the linear expansion coefficient of the first and second members and the linear expansion coefficient of the interposition part, so that variation in strength can be suppressed.

A second invention is the ceramic structure according to the first invention, wherein the A is 23% or more and 30% or less.
According to this ceramic structure, the segregation of silicon and the porosity of the interposition part are reduced, and variation in strength can be suppressed.

According to a third invention, in the first or second invention, the interposition part includes a central layer, a first side layer located between the central layer and the first member, the central layer, and the first A ratio of the area of silicon included in the cross section of the first side surface layer to the area of the cross section of the first side surface layer is E1. The ratio of the area of the silicon included in the cross section of the second side surface layer to the area of the cross section of the second side surface layer is E2, and is included in the cross section of the central layer relative to the area of the cross section of the central layer. The ratio of the area of silicon to be obtained is F, and at least one of E1 and E2 is a ceramic structure characterized by being lower than F.

  According to this ceramic structure, the ratio of silicon carbide increases in at least one of the vicinity of the interface between the first member and the interposition part and the vicinity of the interface between the second member and the interposition part. Thereby, the improvement in strength can be improved, and variations in strength can be suppressed.

According to a fourth invention, in the third invention, the E1, the E2, and the F satisfy at least one of E1 / F <0.95 and E2 / F <0.95. It is a ceramic structure.

  According to this ceramic structure, the ratio of silicon carbide increases in at least one of the vicinity of the interface between the first member and the interposition part and the vicinity of the interface between the second member and the interposition part. Thereby, intensity | strength can be improved. Moreover, variation in strength can be suppressed.

In a fifth aspect based on the third or fourth aspect , the cross section of the central layer is parallel to the first direction perpendicular to the interface between the first member and the interposition part, and to the interface. In the plane including the second direction, and in the cross section of the central layer, the chord length in the first direction of the silicon included in the central layer is the first length of the silicon included in the central layer. It is a ceramic structure characterized by being shorter than the chord length in two directions.

  According to this ceramic structure, the strength of the ceramic structure can be improved. Moreover, variation in strength can be suppressed.

In a sixth aspect based on the fifth aspect , a ratio of the chord length in the first direction of silicon contained in the central layer to the chord length in the second direction of silicon contained in the central layer. Is a ceramic structure characterized by being less than 0.9.

  According to this ceramic structure, the strength of the ceramic structure can be improved. Moreover, variation in strength can be suppressed.

A seventh invention is the ceramic structure according to any one of the first to sixth inventions, wherein an average thickness of the interposition portion is not less than 100 micrometers and not more than 400 micrometers.

  The strength of the interposition part may be lower than the strength of the first member or the second member. According to this ceramic structure, variation in strength can be suppressed due to the thin interposition portion.

An eighth invention is the ceramic according to the seventh invention, wherein the difference between the maximum thickness of the interposition part and the minimum thickness of the interposition part is 100 micrometers or less. It is a structure.
According to this ceramic structure, variation in strength can be suppressed.

According to a ninth invention, in any one of the first to eighth inventions, the interface between the first member and the interposition part includes a first interface and a second interface inclined with respect to the first interface. And the interface between the second member and the interposition part is inclined with respect to the third interface, the third interface facing the first interface via the interposition part, and the interposition part is And a fourth interface opposite to the second interface, wherein the first interface and the second interface are located between the third interface and the fourth interface. It is a structure.

The strength of the interposition part may be lower than the strength of the first member and the strength of the second member.
On the other hand, according to this ceramic structure, in the cross section perpendicular to the direction from the first member to the second member, the ratio of the interposition portion occupying the cross section is small, and the decrease in strength can be suppressed.

Invention of the first zero in the ninth aspect, wherein the interface between the first member and the intermediate portion includes a first curved surface connecting the second interface and the first interface, the second member And the intervening portion has a second curved surface connecting the third interface and the fourth interface.

When forming the ceramic structure, two or more pre-sintered calcined bodies are joined with an adhesive containing silicon carbide powder and a resin. A ceramic structure is formed by impregnating the bonded calcined body with molten Si and performing heat treatment. The joint portion at this time becomes an interposition portion. When the tip of the interface of the joint portion is sharp, the fluidity of the adhesive is lowered at the time of bonding at the sharp portion. For this reason, it is difficult to fill the adhesive in the pointed portion.
On the other hand, according to this ceramic structure, it becomes easy to fill the adhesive by making the tip of the interface a curved surface. Further, by making the tip a curved surface, the occurrence of chipping of the calcined body, the generation of voids, and the occurrence of segregation of silicon can be suppressed.

First aspect of the invention, in the invention of the first 0 and the direction perpendicular to the first surface, in a cross section in a plane containing the direction perpendicular to the third interface, of the first curved surface The ceramic structure is characterized in that a radius of curvature is smaller than a radius of curvature of the second curved surface.

Since the strength of the interposition portion may be lower than the strength of the first member and the strength of the second member, the strength may be partially reduced if the interposition portion is thick.
On the other hand, according to this ceramic structure, since the curvature radius of the first curved surface is smaller than the curvature radius of the second curved surface, the distance between the first curved surface and the second curved surface is reduced. Thereby, the fall of intensity | strength can be suppressed.

First and second invention is the first 0 or the first aspect of the invention, the distance between the first curved surface and the second curved surface, than the distance between said third interface and said first interface The ceramic structure is short and shorter than a distance between the second interface and the fourth interface.

When forming the ceramic structure, two or more pre-sintered calcined bodies are joined with an adhesive containing silicon carbide powder and a resin. A ceramic structure is formed by impregnating the bonded calcined body with molten Si and performing heat treatment. The joint portion at this time becomes an interposition portion.
According to this ceramic structure, since the distance between the first curved surface and the second curved surface is short, it is possible to prevent the adhesive from being filled between the first curved surface and the second curved surface. Therefore, the strength can be increased.

Invention of the first 3, the first to any one invention of the first 2, Weibull modulus from flexural strength was calculated in the ceramic structure is a ceramic structure, characterized in that at least 10 .
According to this ceramic structure, an integrated ceramic structure having a large size and a complicated shape can be manufactured with excellent reliability.

Invention of the first 4, in any one invention of the first to 1 3, open porosity in the intermediate part is a ceramic structure, characterized in that 0.1% or less.

  According to this ceramic structure, it is possible to manufacture an integrated ceramic structure having a large size and a complicated shape that is excellent in durability, generates little outgas. For example, by using this ceramic structure for a member (structure) in a vacuum chamber of a semiconductor manufacturing apparatus or the like, the time to reach the target vacuum can be shortened.

Invention of the first 5, in any one invention of the first to 1 4, the volume resistivity of the ceramic structure is characterized in that it is 2.0 × 10 ^-2 ohm-cm or less It is a ceramic structure.

  For example, if this ceramic structure is used in a semiconductor manufacturing apparatus using an electron beam, the volume resistivity is low, so that the influence of a magnetic field caused by eddy current can be suppressed.

Invention of the first 6, in any one invention of the first to 1 5, the length of the at least one side is longer than 1 meter that has a plurality of inter-sky surrounded by at least three faces It is the ceramic structure characterized.

  According to this ceramic structure, variation in strength can be suppressed in a ceramic structure having a large and complicated shape.

Invention of the first 7 is a structural member for a semiconductor manufacturing apparatus which comprises a first through ceramic structure of any one invention of the first 6.
According to the structural member for a semiconductor manufacturing apparatus, variation in strength can be suppressed.

  According to the aspect of the present invention, a ceramic structure that can suppress variation in strength in the interposition portion is provided.

FIG. 1A and FIG. 1B are diagrams illustrating a ceramic structure according to an embodiment. It is sectional drawing which illustrates the ceramic structure which concerns on embodiment. It is a table | surface which shows the evaluation result of a ceramic structure. It is sectional drawing explaining the thickness of a junction part. It is a graph which shows the relationship between the average thickness of a junction part, and bending strength. It is a graph which shows the relationship between the average thickness of a junction part, and a Weibull coefficient. It is a table | surface which shows the evaluation result of a ceramic structure. It is a laser microscope image in the cross section of a ceramic structure. It is a graph which shows the relationship between Si area ratio and bending strength. It is a graph which shows the relationship between Si area ratio and a Weibull coefficient. It is a graph which shows the relationship between Si area standard deviation ratio and bending strength. It is a graph which shows the relationship between Si area standard deviation ratio and a Weibull coefficient. It is a laser microscope image of the ceramic structure which concerns on embodiment. It is a table | surface which shows the evaluation result of a ceramic structure. FIG. 15A and FIG. 15B are schematic diagrams for explaining the chord length. It is sectional drawing which illustrates another ceramic structure which concerns on embodiment. It is sectional drawing which illustrates a ceramic structure. It is sectional drawing which illustrates another ceramic structure which concerns on embodiment. It is a flowchart which illustrates the manufacturing method of a ceramic structure. It is a schematic diagram which illustrates an electronic exposure apparatus. FIG. 21A to FIG. 21C are perspective views illustrating the ceramic structure according to the embodiment. FIG. 22A and FIG. 22B are perspective views illustrating the ceramic structure according to the embodiment.

Embodiments of the present invention will be described below with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.
FIG. 1A and FIG. 1B are diagrams illustrating a ceramic structure according to an embodiment. FIG. 1A is a perspective view illustrating a ceramic structure 100 according to the embodiment. FIG. 1B is a cross-sectional view showing a part of the cross section of the ceramic structure 100 taken along the line A1-A2 shown in FIG.
As shown in FIGS. 1A and 1B, the ceramic structure 100 includes a first member 10, a second member 20, and a joint (intervening portion) 30. The first member 10 and the second member 20 each contain silicon (Si) and silicon carbide (SiC). The joint portion 30 is an intermediate layer provided between the first member 10 and the second member 20. Bonding portion 30 is a layer for bonding first member 10 and second member 20 and includes silicon and silicon carbide. For example, each of the first member 10, the second member 20, and the joint portion 30 is made of reaction sintered silicon carbide (reaction sintered SiC).

  The first member 10 has a joint surface 11, the second member 20 has a joint surface 12, and the joint portion 30 joins the joint surface 11 and the joint surface 12.

  In the following description, a direction from the joint surface 11 to the joint surface 12 is defined as an X direction (first direction). A direction perpendicular to the X direction is defined as a Y direction, and a direction perpendicular to the X direction and the Y direction is defined as a Z direction (second direction).

  The joint surface 11 is a surface extending along the YZ plane. The X direction is a direction substantially perpendicular to the joint surface 11, in other words, a direction perpendicular to the interface (first interface) between the first member 10 and the joint portion 30. The Y direction and the Z direction are substantially parallel to the joint surface 11, in other words, are directions parallel to the interface between the first member 10 and the joint portion 30. The bonding surface 12 is a surface substantially parallel to the bonding surface 11.

  In this example, the ceramic structure 100 has a rectangular parallelepiped shape. However, the shape of the ceramic structure according to the embodiment is not limited to a rectangular parallelepiped.

FIG. 2 is a cross-sectional view illustrating a ceramic structure according to the embodiment.
FIG. 2 is an enlarged view of the region R (in the vicinity of the joint 30) shown in FIG.
In the following description, the value of the Si area average ratio in the cross section of the joint (for example, the joint 30) is represented as A. The Si area average ratio in the cross section of the joint is the average ratio of the area of Si included in the cross section with respect to the area of the cross section of the joint.
Moreover, the value of the Si area average ratio in the cross section of the 1st member 10 is represented as B1. The Si area average ratio in the cross section of the first member 10 is the average ratio of the area of Si included in the cross section to the cross section area of the first member 10. Similarly, the value of the Si area average ratio in the cross section of the second member 20 is represented as B2.

Here, calculation of the Si area average ratio (percent:%) will be described. In the present specification, the Si area average ratio is as follows.
First, a plurality of observation regions are set in a cross section of a certain member. For example, as shown in FIG. 2, a plurality of observation regions R <b> 3 are set in the case of the joint portion 30, a plurality of observation regions R <b> 1 are set in the case of the first member 10, and in the case of the second member 20. A plurality of observation regions R2 are set. Next, the Si area ratio (%) is calculated for one observation region. This Si area ratio is the ratio of the area of silicon (Si) contained in the observation region to the area of one observation region. In other words, the Si area ratio is the ratio of the area occupied by Si in one observation region. A method for measuring the area of Si included in the observation region will be described later.

The Si area average ratio is an average value of a plurality of observation areas of the Si area ratio. That is, the Si area average ratio is calculated by the equation (1).
n is the number of samples (the number of observation regions in the target member). X _i is the Si area ratio in the i-th sample.

  Therefore, in the example shown in FIG. 2, the Si area average ratio (A) in the cross section of the joint portion 30 is an average value of the Si area ratios in the plurality of observation regions R3. Similarly, the Si area average ratio (B1) in the cross section of the first member 10 is an average value of the Si area ratios in the plurality of observation regions R1. The Si area average ratio (B2) in the cross section of the second member 20 is an average value of the Si area ratios in the plurality of observation regions R2.

  In the following example, the material of the first member 10 (material of the ceramic bonded body) and the material of the second member 20 (material of the ceramic bonded body) are substantially the same. Therefore, B1 is substantially equal to B2. Below, the value of the Si area average ratio in the cross section of a base material (one of the ceramic joined bodies) is represented by B. In the ceramic structure 100, B means either B1 or B2. However, B1 and B2 may be different from each other.

In the ceramic structure 100 according to the embodiment, A and B are:
1.0 <A / B <1.3 (2)
Meet. (That is, one or both of 1.0 <A / B1 <1.3 and 1.0 <A / B2 <1.3 are satisfied.)
In the following description, the value of the Si area standard deviation in the cross section of the joint (for example, the joint 30) is represented by C. The Si area standard deviation in the cross section of the joint is the standard deviation of the ratio of the area of Si included in the cross section to the area of the cross section of the joint.
The value of the Si area standard deviation in the cross section of the first member 10 is represented as D1. The Si area standard deviation in the cross section of the first member 10 is the standard deviation of the ratio of the area of Si contained in the cross section to the area of the cross section of the first member 10. Similarly, the value of the Si area standard deviation in the cross section of the second member 20 is represented as D2.

Here, calculation of the Si area standard deviation will be described. In the present specification, the Si area standard deviation is as follows.
The Si area standard deviation is a standard deviation in a plurality of observation regions of the Si area ratio. That is, the Si area standard deviation is calculated by the equation (3).

n is the number of samples (the number of observation regions in the target member). X _i is the Si area ratio in the i-th sample.

  Therefore, in the example shown in FIG. 2, the Si area standard deviation (C) in the cross section of the joint portion 30 is the standard deviation of the Si area ratio in the plurality of observation regions R3. Similarly, the Si area standard deviation (D1) in the cross section of the first member 10 is a standard deviation of the Si area ratio in the plurality of observation regions R1. The Si area standard deviation (D2) in the cross section of the second member 20 is the standard deviation of the Si area ratio in the plurality of observation regions R2.

  In the following example, D1 is substantially equal to D2. Below, the value of Si area average ratio in the cross section of a base material is represented as D. In the ceramic structure 100, D means either D1 or D2. However, D1 and D2 may be different from each other.

In the ceramic structure 100 according to the embodiment, C and D are:
1.3 <C / D <3.3 (4)
Meet. (That is, one or both of 1.3 <C / D1 <3.3 and 1.3 <C / D2 <3.3 are satisfied.)

  The illustrated cross section and observation region are examples. The cross section for calculating the Si area ratio is, for example, the ZX plane, but the cross section for calculating the Si area ratio and the positions and the number of observation regions in the cross section are not limited to the above.

By joining a plurality of members such as the first member 10 and the second member 20 by the joint portion, a member having a complicated shape or a large-sized member can be formed.
Here, as a method of bonding a plurality of members, there is a method of bonding a plurality of members (bonded bodies) with an adhesive and bonding them by reactive sintering. However, after bonding the object to be bonded (adhered object) with an adhesive, the adhesive causes curing shrinkage. At this time, a reaction force may act on the shrinkage force of the adhesive. For example, a frictional force may be received from the surface with which the object is in contact, or a frictional force may be generated in a moving mechanism such as a stage to which the object is fixed. When such a reaction force is generated, curing shrinkage of the adhesive is inhibited. Thereby, a space | gap and a crack may generate | occur | produce in the interface of an adhesive bond layer or a to-be-joined body, and an adhesive bond layer. For this reason, voids and cracks remain or a large free silicon phase may be generated in the finally obtained sintered joined body. If the structure of the object to be bonded is different from the structure of the bonded portion (adhesive layer after sintering), residual stress due to a difference in thermal expansion may occur in the vicinity of the bonded portion. Further, the bonding strength may vary due to the residual stress.

On the other hand, the inventors of the present application have found that the variation in the bonding strength in the ceramic structure 100 can be suppressed by the configuration shown in the above formulas (2) and (4). Furthermore, when the average thickness of the bonding portion 30 is set to 100 micrometers (μm) or more and 400 μm or less, variation in bonding strength can be further suppressed.
Hereinafter, the examination by the inventors will be described.

(Example)
The inventors of the present application evaluated the physical properties of the ceramic structures (Examples 1 to 8) according to the present embodiment described with reference to FIGS. 1 and 2 and the ceramic structures (Comparative Examples 1 to 3) according to Comparative Examples. .
Each example and each comparative example are similar to the ceramic structure 100 described with reference to FIG. 1A and FIG. 1B, and include two ceramic joined bodies (for example, the first member 10) containing reactively sintered silicon carbide. And a second member 20). Two ceramic to-be-joined bodies have the joining surfaces (for example, joining surface 11 and joining surface 12) which are arrange | positioned substantially parallel. Each example and each comparative example includes reaction-sintered silicon carbide and has a joint (for example, joint 30) that joins the joint surfaces.

FIG. 3 is a table showing the evaluation results of the ceramic structure.
FIG. 3 shows the average thickness (μm), bending strength (megapascal: MPa), and Weibull coefficient of the joints for Examples 1 to 5, Comparative Example 1 and Comparative Example 2.

Here, the average thickness of the joint will be described.
FIG. 4 is a cross-sectional view illustrating the thickness of the joint. This is an enlarged view schematically showing the vicinity of the joint 30 in the cross-sectional view shown in FIG. As already described, the joint surface 11 is a surface extending along the YZ plane. Further, the joint surface 11 and the joint surface 12 are arranged substantially in parallel. However, as shown in FIG. 4, the joint surface may have a slight unevenness when viewed in an enlarged manner. Moreover, the joint surface 11 and the joint surface 12 may be slightly inclined with respect to each other.

  The junction thickness T (μm) refers to the length of the junction along the X direction. For example, the thickness T of the joint portion 30 is a distance along the X direction between the joint surface 11 of the first member 10 and the joint surface 12 of the second member 20. The average thickness Tave (μm) of the joint portion means an average value of the thickness T in the YZ plane. The maximum value of the thickness of the bonded portion is the maximum value of the thickness T (μm), and corresponds to, for example, the thickness Tmax shown in FIG. Moreover, the minimum value of the thickness of a junction part is the minimum value of thickness T (micrometer), for example, is equivalent to thickness Tmin shown in FIG.

  The bending strength shown in FIG. 3 is a measurement result of a three-point bending strength measured according to JIS R 1601. In the measurement of the three-point bending strength, a weight is applied so that the joint is at the center, and the three-point bending strength of the sample is measured.

The Weibull coefficient shown in FIG. 3 is a Weibull coefficient calculated according to JIS R 162 5 from measured three-point bending strength data. The Weibull coefficient means that the larger the Weibull coefficient, the smaller the variation in bending strength.

FIG. 5 is a graph showing the relationship between the average thickness of the joint and the bending strength.
FIG. 6 is a graph showing the relationship between the average thickness of the joint and the Weibull coefficient.
These are graphs of the values shown in FIG.
As shown in FIG. 5, when the average thickness of the joint exceeds 700 μm, the bending strength rapidly decreases. In addition, as shown in FIG. 6, the Weibull coefficient decreases when the average thickness of the joint portion exceeds 200 μm, and further, the Weibull coefficient rapidly decreases when the average thickness of the joint portion exceeds 500 μm. In general, the Weibull coefficient is required to be 10 or more. However, when the average thickness of the joint exceeds 500 μm, the Weibull coefficient is less than 10.

As described above, the average thickness of the bonded portion is desirably 500 μm or less. As a result, a ceramic structure having high bending strength and high reliability can be obtained.
On the other hand, when joining non-sintered members, sufficient processing accuracy may not be obtained in processing of the joint surface. In addition, when a relatively large member having a width exceeding 500 mm is joined, the accuracy with which joint surfaces facing each other through the joint portion are arranged in parallel may be reduced. However, the range in which the distance between the joint surfaces (thickness T of the joint portion) varies by adjusting the setup when joining the joint surfaces and performing high-accuracy processing suitable for the ceramic workpiece. (Difference between the thickness Tmax and the thickness Tmin) can be 100 μm or less.

  Therefore, in the embodiment, the average thickness of the joint portion 30 is set to, for example, 100 μm or more and 400 μm or less. Further, the difference between the maximum value of the thickness of the bonding portion 30 and the minimum value of the thickness of the bonding portion 30 is 100 μm or less. At this time, the Weibull coefficient is 10 or more. The strength of the joint 30 may be lower than the strength of the first member 10 and the strength of the second member 20, but by reducing the average thickness of the joint 30 as described above, a stable strength can be obtained. can get. Variations in bonding strength at the bonding portion 30 can be suppressed. Thereby, it is possible to manufacture an integrated ceramic structure having a large size and a complicated shape with excellent reliability.

FIG. 7 is a table showing the evaluation results of the ceramic structure.
FIG. 7 shows Si area ratio (%), Si area average ratio (%), Si area standard deviation, Si area ratio, Si area standard deviation ratio, bending strength (Examples 6 to 8 and Comparative Example 3). MPa), Weibull coefficient, open porosity (%), and volume resistivity (ohm centimeter: Ω · cm).

  A laser microscope was used for analysis of the Si area ratio. Olympus OLS4100 was used for the laser microscope. The objective lens magnification was 100 times, the zoom magnification was 1 time, and the size of one field of view (one observation area) was 128 μm × 128 μm, and a luminance image in the range was taken. An example of a photographed image is shown in FIG.

FIG. 8 is a laser microscope image in a cross section of the ceramic structure.
As shown in FIG. 8, the reaction-sintered silicon carbide includes a plurality of SiC particles 71 and a Si portion 75 (free silicon phase). The SiC particles 71 include coarse particle raw material SiC particles and fine particle raw material SiC particles. The Si portion 75 is located between a plurality of SiC particles and is continuous in a network shape (network shape).

  The photographed image is, for example, a monochrome image. In the photographed image, the luminance of the Si portion 75 is higher than the luminance of other portions. The high luminance part can be separated by image analysis. For image analysis, WinROOF ver6.5 made by Mitani Corporation was used. An image obtained by a laser microscope is separated into an Si portion 75 and other portions by binarization (valley method). Then, the ratio of the area of the Si portion 75 to the visual field area (Si area ratio) was calculated.

  In each of the examples and comparative examples, the Si area ratio at 10 locations (10 visual fields) of the joint and the Si area ratio at 10 locations (10 visual fields) of the base material were calculated. FIG. 7 shows the calculated range of the Si area ratio of the joint and the calculated range of the Si area ratio of the base material in each of the example and the comparative example. Then, according to the equations (1) and (3) described with reference to FIG. 2, in each of the examples and comparative examples, the Si area average ratio (A and B) for the cross section of each part (joint part and base material) and the Si area Standard deviations (C and D) were calculated.

  The Si area ratio shown in FIG. 7 is a value (A / B) obtained by dividing A by B in each of the example and the comparative example. Further, the Si area standard deviation ratio is a value obtained by dividing C by D (C / D) in each of the example and the comparative example.

The method for calculating the bending strength and the Weibull coefficient is the same as that described with reference to FIG.
The open porosity shown in FIG. 8 is a measurement result of the open porosity of the joint measured according to JIS R 1634.
The volume resistivity shown in FIG. 8 is a measurement result of the volume resistivity of a member including a joint portion measured according to JIS R 1650-2. In the measurement of the volume resistivity, an electrode is attached to each of the two ceramic bonded bodies bonded to each other, and the resistance through the bonded portion is measured.

FIG. 9 is a graph showing the relationship between the Si area ratio and the bending strength.
FIG. 10 is a graph showing the relationship between the Si area ratio and the Weibull coefficient.
Each of the horizontal axis of FIG. 9 and the horizontal axis of FIG. 10 represents the Si area ratio (A / B) shown in FIG. The vertical axis in FIG. 9 and the vertical axis in FIG. 10 represent the bending strength shown in FIG. 7 and the Weibull coefficient shown in FIG. In each of Examples 6 to 8 and Comparative Example 3, the average thickness of the bonded portion is set to 200 μm.

  As shown in FIG. 9, high bending strength is obtained in the range of 1.0 <A / B <1.3. Further, although the Weibull coefficient is required to be 10 or more, as shown in FIG. 10, a high Weibull coefficient of 10 or more is obtained in the range of 1.0 <A / B <1.3. And when A / B becomes 1.3 or more, it turns out that a Weibull coefficient falls rapidly. As shown in FIG. 7, the average Si area product ratio (A) of the joint in Example 6 is 23.22%, and the average Si area ratio (A) of the joint in Example 8 is 30.22%. 36%. In the embodiment, the Si area average ratio (A) of the joint is desirably 23% or more and 30% or less.

FIG. 11 is a graph showing the relationship between the Si area standard deviation ratio and the bending strength.
FIG. 12 is a graph showing the relationship between the Si area standard deviation ratio and the Weibull coefficient.
Each of the horizontal axis of FIG. 11 and the horizontal axis of FIG. 12 represents the Si area standard deviation ratio (C / D) shown in FIG. The vertical axis in FIG. 11 and the vertical axis in FIG. 12 represent the bending strength shown in FIG. 7 and the Weibull coefficient shown in FIG.

  As shown in FIG. 11, high bending strength is obtained in the range of 1.3 <C / D <3.3. Further, as shown in FIG. 12, a high Weibull coefficient of 10 or more is obtained in the range of 1.3 <C / D <3.3.

  Furthermore, as shown in FIG. 7, in the example satisfying 1.0 <A / B <1.3 and 1.3 <C / D <3.3, the open porosity is small, 0.01% or less. It is. On the other hand, in the comparative example in which A / B and C / D deviate from the above ranges, the open porosity rapidly increases to 0.91%. Accordingly, the bending strength is low in the comparative example. Moreover, in the comparative example, it can be seen that the Weibull coefficient is small and the variation in bonding strength is large.

  If the structure of the object to be joined is different from the structure of the joint, residual stress due to a difference in thermal expansion may occur in the vicinity of the joint. Residual stress may cause variations in bonding strength. On the other hand, in the embodiment, A and B satisfy 1.0 <A / B <1.3. C and D satisfy 1.3 <C / D <3.3. Thereby, for example, it is considered that the difference between the linear expansion coefficient of the first member 10 and the linear expansion coefficient of the joint portion 30 is small and the residual stress is small. In the embodiment, the segregation of silicon and the open porosity of the bonded portion are reduced, and variations in bonding strength can be suppressed.

In the ceramic structure according to the embodiment, the Weibull coefficient calculated from the bending strength is 10 or more. For this reason, it is excellent in reliability (durability), generation | occurrence | production of outgas is small, and the monolithic ceramic structure which has a large and complicated shape can be manufactured.
For example, by using the ceramic structure according to the embodiment as a member in a vacuum chamber of a semiconductor manufacturing apparatus or the like, it is possible to shorten the time for reaching the target vacuum degree.

Furthermore, as shown in FIG. 7, the volume resistivity of the member including the joint portion 30 is low and is 1.8 × 10 ⁻² Ωcm or less. In particular, in Example 6, the volume resistivity of the member including the joint portion 30 is 7.8 × 10 ⁻³ Ωcm. In the embodiment, the volume resistivity of the member including the joint portion 30 is preferably 2.0 × 10 ⁻² Ωcm or less. Thereby, for example, when the ceramic structure according to the embodiment is used in a semiconductor manufacturing apparatus (see FIG. 20) using an electron beam, the influence of a magnetic field caused by an eddy current can be suppressed.

FIG. 13 is a laser microscope image of the ceramic structure according to the embodiment.
FIG. 13 shows a cross section in the ZX plane in the vicinity of the joint 30. Olympus OLS4100 was used for cross-sectional observation, and the objective lens magnification was 20 times, the zoom magnification was 1 time, and the field of view was 640 μm × 640 μm.
As shown in FIG. 13, the joint portion 30 includes a central layer (central region) 31 and a side layer (side region) 32. The side layer 32 (the first side layer 32 a and the second side layer 32 b) is located on both sides of the joint portion 30. That is, the first side layer 32 a is located between the central layer 31 and the first member 10. The second side layer 32 b is located between the central layer 31 and the second member 20.

In the following description, the value of the Si area ratio in the cross section of the central layer (for example, the central layer 31) is represented as F. That is, F is the ratio of the area of Si included in the cross section to the area of the cross section of the central layer.
Further, the value of the Si area ratio in the cross section of the first side layer (for example, the first side layer 32a) is represented as E1. That is, E1 is the ratio of the area of Si included in the cross section to the area of the cross section of the first side layer. Similarly, the value of the Si area ratio in the cross section of the second side layer (for example, the second side layer 32b) is represented as E2. That is, E2 is the ratio of the area of Si contained in the cross section to the area of the cross section of the second side layer.

In the present specification, E1, E2 and F are calculated as follows.
First, in the same manner as described with reference to FIG. 13, a laser microscope image of the cross section of the joint is obtained. In the obtained image, WinROOF ver6.5 manufactured by Mitani Corporation is used, and the Si portion and other portions are separated by binarization (valley method). That is, the portion with high luminance is the Si portion. In the region of 65 μm × 252 μm in the central layer, F is the ratio of the area of the Si part included in the region to the area of the region. In the 65 μm × 252 μm region of the first side surface layer, the ratio of the area of the Si portion included in the region to the area of the region is E1. In the region of 65 μm × 252 μm in the second side layer, the ratio of the area of the Si part included in the region to the area of the region is E2.

In the following example, E1 is substantially equal to E2. Hereinafter, the value of the Si area ratio in the cross section of the side layer is represented by E. E means either E1 or E2. However, E1 and E2 may have different values.
In addition, when the junction part 30 has the center layer 31 and the side layer 32, when calculating the Si area average ratio (A) in the cross section of the junction part 30, it is biased to either the center layer 31 or the side layer 32. The position, size, number, etc. of the plurality of observation regions R3 are set so as not to be present. For example, when calculating the Si area average ratio (A) in the cross section of the joint 30, the observation region is set so that the average of the Si area ratio in the entire joint 30 included in the observed cross section is calculated. The

FIG. 14 is a table showing the evaluation results of the ceramic structure.
FIG. 14 shows the Si area ratio (E) in the cross section of the side layer, the Si area ratio (F) in the cross section of the central layer, and the ratio of E to F (E) for each of Examples 6 to 8 and Comparative Example 3. / F). Further, the bending strength and the Weibull coefficient shown in FIG. 14 are the same as those shown in FIG.

  As shown in FIG. 14, in the example, the ratio (E / F) is less than 1. That is, the Si area ratio (E) in the cross section of the side layer 32 is lower than the Si area ratio (F) in the cross section of the central layer 31. In other words, in the embodiment, at least one of E1 and E2 is lower than F (E1 / F <1.0 and E2 / F <1.0 are satisfied).

  When the ratio (E / F) is less than 1, the proportion of SiC particles in the side layer 32 is considered to be higher than the proportion of SiC particles in the central layer 31. That is, by setting the ratio (E / F) to less than 1, the ratio of silicon carbide (SiC) in the vicinity of the interface between the base material (first member 10 or second member 20) and joint 30 increases. Thereby, strength (bending strength) can be improved. Moreover, variation in strength can be suppressed. In an embodiment, the ratio (E / F) is preferably less than 1.0, more preferably less than 0.95 (E1 / F <0.95 and / or E2 / F <0.95). Hold).

  Further, FIG. 14 shows the chord length (Lx) in the X direction of silicon included in the center layer, the chord length (Lz) in the Z direction of silicon included in the center layer, and the ratio of Lx to Lz (Lx). / Lz).

FIG. 15A and FIG. 15B are schematic diagrams for explaining the chord length.
FIG. 15A is a laser microscope image similar to FIG. As shown in FIG. 15A, in the cross section of the central layer 31 of the joint portion, the Si portion 75 includes a plurality of Si spots 75s. In this cross section, each of the plurality of Si spots 75s is surrounded by SiC particles 71, and the plurality of Si spots 75s are separated from each other.

FIG. 15B is a schematic view illustrating one Si spot 75s.
The chord length Lxs in the X direction of the Si spot 75s is a length when the Si spot 75s is cut in the X direction. In other words, the chord length Lxs in the X direction of the Si spot 75s is a distance between two points separated from each other in the X direction on the outer periphery of the Si spot 75s.
Similarly, the chord length Lzs in the Z direction of the Si spot 75s is a length when the Si spot 75s is cut in the Z direction. In other words, the chord length Lzs in the Z direction of the Si spot 75s is a distance between two points separated from each other in the Z direction on the outer periphery of the Si spot 75s.

In the present specification, Lx and Lz are calculated as follows.
First, in the same manner as described with reference to FIG. 13, a laser microscope image of the cross section of the joint is obtained. In the obtained image, WinROOF ver6.5 manufactured by Mitani Corporation is used, and a 65 μm × 640 μm region in the central layer is separated into an Si portion and other portions by binarization (valley method). That is, the portion with high luminance is the Si portion. For the separated Si part, the chord length is calculated using WinROOF ver6.5. That is, the average value of the chord length in the horizontal direction (X direction) is obtained for each Si spot in the Si portion. Among the average values of the chord lengths in the horizontal direction of the plurality of Si spots, the maximum value is defined as “chord length (Lx) in the X direction of silicon included in the center layer”. Further, an average value of chord lengths in the vertical direction (Z direction) is obtained for each Si spot in the Si portion. Of the chord lengths in the vertical direction of the plurality of Si spots, the maximum value is defined as “the chord length (Lz) in the Z direction of silicon included in the center layer”.

  As shown in FIG. 14, in Examples 6 to 8, the ratio (Lx / Lz) is less than 1. That is, in the ZX cross section of the central layer 31 in the embodiment, the chord length in the X direction (first direction) of silicon included in the central layer 31 is the same as that in the Z direction (second direction) of silicon included in the central layer 31. Shorter than string length. In an embodiment, the ratio (Lx / Lz) is preferably less than 0.9, more preferably less than 0.7. Thereby, for example, residual voids in the central layer 31 can be suppressed. Strength (bending strength) can be improved and variation in strength can be suppressed.

FIG. 16 is a cross-sectional view illustrating another ceramic structure according to the embodiment.
As illustrated in FIG. 16, the first member 10 of the ceramic structure 101 according to the embodiment further includes a bonding surface 14. The second member 20 further has a joint surface 15. The joint portion 30 includes a first portion 30p that joins the joint surface 11 and the joint surface 12, and a second portion 30q that joins the joint surface 14 and the joint surface 15.

In other words, the interface 40 a between the first member 10 and the joint portion 30 includes the first interface 41 and the second interface 42. The first interface 41 is an interface between the bonding surface 11 and the first portion 30p. The second interface 42 is an interface between the bonding surface 14 and the second portion 30q. The second interface 42 is inclined with respect to the first interface 41.
Further, the interface 40 b between the second member 20 and the joint portion 30 includes a third interface 43 and a fourth interface 44. The third interface 43 is an interface between the bonding surface 12 and the first portion 30p, and faces the first interface 41 through the first portion 30p. The fourth interface 44 is an interface between the joint surface 15 and the second portion 30q. The fourth interface 44 is inclined with respect to the third interface 43 and faces the second interface 42 via the second portion 30q.

  Each of the first to fourth interfaces 41 to 44 is planar. The first interface 41 and the third interface 43 are arranged substantially in parallel. The second interface 42 and the fourth interface 44 are disposed substantially in parallel. FIG. 16 shows a cross section of the ceramic structure 101 in a plane including the direction D1 perpendicular to the first interface 41 and the direction D2 perpendicular to the second interface 42.

  The first interface 41 and the second interface 42 are located between the third interface 43 and the fourth interface 44. That is, the first member 10 has a convex shape toward the second member 20 between the first interface 41 and the second interface 42. The second member 20 has a concave shape corresponding to the convex shape of the first member.

  Thereby, the ratio of the joint portion 30 occupying the cross section of the ceramic structure 101 is reduced, and a decrease in strength can be suppressed. For example, FIG. 17A shows a cross section of a ceramic structure similar to that in FIG. 16, and FIG. 17B shows a cross section of the ceramic structure in the plane PL shown in FIG. FIG. 17C shows a cross section of the ceramic structure when the joint 30 is parallel to the plane PL, and FIG. 17D shows the ceramic structure in the plane PL shown in FIG. A cross section of the body is shown. The plane PL is a plane perpendicular to the direction from the first member 10 toward the second member 20. In the example of FIG. 17B, the proportion of the joint portion 30 occupying the cross section of the ceramic structure is smaller than in the example of FIG.

  Further, as shown in FIG. 16, the interface 40 a between the first member 10 and the joint portion 30 has a first curved surface 51 that connects the first interface 41 and the second interface 42. That is, the tip of the interface 40a has an R shape. In addition, the interface 40 b between the second member 20 and the joint portion 30 has a second curved surface 52 that connects the third interface 43 and the fourth interface 44. That is, the tip of the interface 40b has an R shape.

  When forming the ceramic structure, two or more pre-sintered calcined bodies are joined with an adhesive containing silicon carbide powder and a resin. A ceramic structure is formed by impregnating the bonded calcined body with molten Si and performing heat treatment. When the tip of the interface of the joint portion is sharp, the fluidity of the adhesive is lowered at the time of bonding at the sharp portion. For this reason, in the pointed part, it is difficult to fill the adhesive on the calcined body side having a concave shape. On the other hand, it becomes easy to fill the adhesive by making the tip of the interface a curved surface. In addition, by making the tip part a curved surface, the occurrence of chipping of the calcined body, the generation of voids, and the occurrence of segregation of silicon can be suppressed.

FIG. 18 is a cross-sectional view illustrating another ceramic structure according to the embodiment.
FIG. 18 is an enlarged view of the region RA shown in FIG.
As shown in FIG. 18, the curvature of the first curved surface 51 is higher than the curvature of the second curved surface 52 in this cross section. That is, the curvature radius Ra of the first curved surface 51 is smaller than the curvature radius Rb of the second curved surface 52. Further, the distance Da between the first curved surface 51 and the second curved surface is shorter than the distance Db between the first interface 41 and the third interface 43, and the distance between the second interface 42 and the fourth interface 44. It is shorter than the distance Dc.

  The distance Da is the minimum value of the distance between the first curved surface 51 and the second curved surface 52 along the normal direction of the first curved surface 51. The distance Db is a distance between the first interface 41 and the third interface 43 along the direction D1. The distance Dc is a distance between the second interface 42 and the fourth interface 44 along the direction D2.

  The strength of the joint portion 30 may be lower than the strength of the first member 10 and the strength of the second member 20. When the curvature radius Ra is larger than the curvature radius Rb, the distance Da becomes longer than the distances Db and Dc, and the strength may be partially reduced. On the other hand, by making the curvature radius Ra smaller than the curvature radius Rb, the distance Da becomes shorter than the distances Db and Dc, and a decrease in strength can be suppressed. Further, since the distance Da is short, it is possible to prevent the adhesive from being filled between the first curved surface 51 and the second curved surface 52 when the calcined body is bonded in the formation of the ceramic structure. Therefore, the strength can be increased.

Next, with respect to Examples 1 to 8 and Comparative Examples 1 to 3, a method for preparing samples will be described.
FIG. 19 is a flowchart illustrating a method for manufacturing a ceramic structure.
In step S110, a molded body to be a ceramic bonded body is molded and dried. First, two types of raw materials, a coarse SiC raw material and a fine SiC raw material, were prepared. The average particle diameter in the coarse SiC raw material is about 20 to 100 μm, and the average particle diameter in the fine SiC raw material is about 0.1 to 1 μm. These two kinds of raw materials are blended in a range where high density filling is achieved. In this blending, the blending amount in which the ratio of the weight of the coarse particles to the weight of the fine particles was 7: 3 was set as the basic blending amount, and the blending amount was adjusted based on the selection conditions for the particle diameter of the starting material. 5 to 15% by weight of carbon powder was prepared with respect to the total amount of SiC raw material. The dispersant, the prepared SiC powder, and the carbon powder were added to water, mixed with a ball mill, and then added with 1 to 10% by weight of an acrylic binder to prepare a raw material for casting. After the defoaming treatment was performed on the casting raw material, a molded body was obtained by casting. The obtained molded body was demolded and dried. In casting molding, the amount of water added was adjusted so that the viscosity of the casting raw material was such that the casting raw material was poured into the casting mold. Moreover, an antifoamer was added as needed to assist the defoaming step.

  In step S120, the molded body obtained by casting is temporarily fired. The obtained molded body is calcined in a temperature range of 1600 to 2000 ° C. Thus, the formed body was a ceramic bonded body.

  In step S130, the ceramic bonded body (calcined body) is processed. If necessary, the ceramic workpiece was mechanically processed to form a joining surface. A plurality of ceramic workpieces necessary for bonding were prepared, and a bonding surface was formed by machining or the like in each. On the joint surface, removal work such as processing waste and chips was performed.

  In step S140, the ceramic workpiece is joined. First, the same raw material as the above-mentioned SiC powder and carbon powder was blended in the same blending amount as the above-mentioned blending amount to prepare an adhesive. A solvent and a dispersant were added to this and mixed to form a slurry. Antifoam was added as needed. In order to promote the improvement of wettability at the interface, a surfactant may be added in a few percent. Various mixing methods such as propeller stirring, ball mill, or centrifugal mixing can be used for the mixing step. After mixing, 5-30% by weight of epoxy resin was added to the slurry. When the solvent was water, an emulsion type resin with a good water compatibility was selected. After thoroughly stirring the bonding agent to which the resin was added, defoaming treatment was performed. The amount of water was adjusted so that the adhesive had a viscosity suitable for the joining operation. The obtained adhesive was applied to the joint surface (joint part surface) of the ceramic joined body prepared in advance, and the joint part of the ceramic joined body was pressed and adhered.

  In Examples 1 to 5 and Comparative Examples 1 and 2, in order to examine the relationship between the average thickness of the joint and the bending strength, and the relationship between the average thickness of the joint and the Weibull coefficient of the bending strength, the average of the joint Adhesion was performed so that the thickness was 100 to 1000 μm. Thereafter, the moving amount and moving speed of the ceramic bonded body were controlled so that the ceramic bonded body followed the shrinkage of the adhesive without resistance.

  In Examples 6 to 8 and Comparative Example 3, in order to investigate the relationship between the difference between the structure of the ceramic body to be bonded and the structure of the bonded portion and the Weibull coefficient of bending strength, the average thickness of the bonded portion is The thickness after shrinkage of the adhesive was adjusted to 200 μm. Moreover, the space | gap which generate | occur | produces in an adhesive agent was controlled by adjusting the moving speed of a ceramic to-be-joined body suitably with respect to the shrinkage | contraction rate of an adhesive agent. Thereby, the above-mentioned Si area ratio can be controlled.

The formed adhesive layer was dried and the resin was cured.
In step S150, firing (impregnation) of the bonded ceramic joined body (and adhesive layer) is performed. First, the fully cured adhesive layer is carbonized by heating at a temperature of 300 ° C. or higher in an inert atmosphere. Then, calcination was performed at 1700 ° C. under vacuum. Thereafter, Si impregnation treatment was performed at a temperature in the range of 1400 ° C. to 1800 ° C. to form reaction sintered silicon carbide, thereby forming a joint.

  In step S160 and step S170, sand blasting and finishing of the main body (impregnated) ceramic joined body are performed. This removed excess Si adhering to the surface.

  By the above, the ceramic structure (sintered body) which concerns on Examples 1-8 and Comparatives 1-3 was created. And the completed sintered compact was evaluated. The evaluation results are as described above with reference to FIGS.

(Use)
The ceramic structure according to the embodiment includes, for example, a structural member for a semiconductor manufacturing apparatus, a structural member for a liquid crystal manufacturing apparatus, a semiconductor-related component (such as a heat sink or a dummy wafer), a high temperature structural member, a mechanical seal member, a brake member, and a sliding component. , Used for apparatus parts and apparatus members such as mirror parts, pump parts and heat exchanger parts. In particular, the ceramic structure according to the embodiment is suitably used for apparatus parts and apparatus members that require low dust generation, low outgas, and conductivity under high vacuum.

An example of a semiconductor manufacturing apparatus is an electron beam exposure apparatus.
FIG. 20 is a schematic view illustrating an electron beam exposure apparatus.
As shown in FIG. 20, the electron exposure apparatus 200 includes an electron beam source 210 (electron gun), a stage 220 on which a processing object W (substrate or the like) is placed, an electromagnetic lens 230, and a deflection that deflects the electron beam. Instrument 240. These are provided in the vacuum chamber 250.

  For example, the ceramic structure according to the embodiment can be used as a member of such an electron beam deflector 240. The deflector 240 has an electrode plate, and scans an electron beam in a predetermined region of the processing object W by a generated electric field. An eddy current may be generated in the deflector 240 by the magnetic field of the electromagnetic lens 230. The magnetic field generated by the generated eddy current may reduce the accuracy of the electron beam. On the other hand, since the volume resistivity of the ceramic structure according to the embodiment is low, the influence of the magnetic field due to the overcurrent can be suppressed.

  You may use the ceramic structure which concerns on embodiment as a structural member for semiconductor manufacturing apparatuses of another semiconductor manufacturing apparatus. The semiconductor manufacturing apparatus includes not only an apparatus used for semiconductor processing such as lithography, CVD (chemical vapor deposition), annealing, and etching, but also an apparatus used when manufacturing a semiconductor product such as an inspection apparatus. The semiconductor manufacturing apparatus is, for example, an exposure apparatus or an inspection apparatus (microscope apparatus). The structural member for a semiconductor manufacturing apparatus is, for example, a member of the above-described deflector 240, a stage or a surface plate such as an exposure apparatus or an inspection apparatus (microscope apparatus), a frame that holds an optical system, a member of a mirror member, or the like. .

(Production method)
A method for manufacturing a ceramic structure according to the embodiment will be described.
In the manufacture of the ceramic structure according to the embodiment, the bonding is performed when the ceramic joined body to be the first member 10 and the second member 20 is in a stage of any one of a molded body, a calcined body, and a reactive sintered body. Do. At least one of the ceramic bonded bodies includes silicon carbide powder and carbon powder.

  Prepare two or more ceramic workpieces. As these ceramic bonded bodies, a molded body formed by casting or a calcined body obtained by calcining the molded body in an inert atmosphere or vacuum is used. In casting molding, a slurry in which silicon carbide and carbon are dispersed in a solvent such as water by using a dispersant and a binder added as a binder is poured into gypsum.

  However, the molded body used as the ceramic article to be bonded is not limited to a cast molding. You may use the molded object formed by granulating the said slurry composition and forming by a mechanical press or CIP shaping | molding. Moreover, you may use the calcined body of these molded objects. Extrusion molding, injection molding, gel cast molding or the like may be used, and the molding method is not limited.

  The bonding surface of the ceramic bonded body may be an unprocessed surface. However, in order to increase the reliability of bonding, it is preferable to process the bonding surface to form a flat surface. In order to improve the adhesion between the bonding surfaces, the surface roughness of the bonding surfaces is preferably large. The increase in surface roughness can increase the adhesion between the bonded portion formed by impregnation with molten Si and the ceramic bonded body, and further the bonding strength thereof.

  Next, the ceramic body is bonded with an adhesive (bonding agent) containing silicon carbide powder and a resin. Bonding is performed by applying an adhesive to the surface of the bonded portion of the ceramic bonded body and pressing the bonded ceramic bodies together. The ceramic workpiece is pressurized until the required thickness is formed. Thereafter, the adhesive is dried. At that time, the adhesive cures and shrinks. In the curing shrinkage, the adhesive receives a reaction force from the surface in contact with the ceramic workpiece. Due to this reaction force, the shrinkage of the adhesive is inhibited, and cracks or voids may be generated in the adhesive or at the interface between the adhesive and the ceramic joined body. For this reason, the amount and speed of movement of the ceramic bonded body are controlled using a uniaxial stage or the like so that the ceramic bonded body follows the shrinkage of the adhesive without resistance.

  The adhesive may contain carbon powder. Regarding the particle size of the silicon carbide powder, the particle size of the carbon powder, and the blending ratio, it is preferable to use the same blending conditions as the blending conditions in the production of the ceramic bonded body. Thereby, at the interface, it is assumed that the adhesive structure and the ceramic structure of the ceramic joined body are approximated to improve the adhesion. In the manufacturing process, it is preferable to select a step of spreading the adhesive as the bonding step. In this case, the viscosity can be arbitrarily adjusted by diluting the adhesive with a solvent or the like. There is no restriction | limiting in the solvent which adjusts a viscosity, Water, alcohol, etc. can be selected arbitrarily. The adhesive is present as an adhesive layer (bonding agent layer) between the ceramics to be bonded. The resin serving as the adhesive component of the adhesive is preferably a thermosetting resin such as a phenol resin, a furan resin, an epoxy resin, or a polyimide resin.

  The average particle size of the silicon carbide powder contained in the adhesive is preferably 0.1 micrometer (μm) or more and 100 μm or less. If the average particle size of the silicon carbide powder is less than 0.1 μm, the dispersion state tends to be non-uniform, and the distribution state of SiC particles and free Si phase becomes non-uniform. If the average particle size of the silicon carbide powder exceeds 100 μm, the size of the free Si phase increases, and the strength of the joint may not be sufficiently increased.

  The average particle size of the carbon powder is preferably 0.01 μm or more and 20 μm or less. If the average particle size of the carbon powder is less than 0.01 μm, the particles of the carbon powder are likely to aggregate, and the preparation of the adhesive becomes unstable. Furthermore, the distribution state of SiC particles and free Si phase at the joint becomes non-uniform. In the embodiment, highly reliable adhesion is achieved by highly dispersing fine carbon powder of 0.01 to 0.08 μm. If the average particle size of the carbon powder exceeds 20 μm, a choking phenomenon is likely to occur, and the strength of the joint may be reduced. Further, the average diameter of the free Si phase becomes large, which may cause a decrease in bonding strength and variations.

  The adhesive preferably contains the silicon carbide powder in a range of 50 to 95 mass% with respect to the total amount of the silicon carbide powder, the carbon powder, and the carbon component derived from the resin. It is preferable that the weight ratio (C / SiC) of the carbon component derived from the carbon powder and the resin to the silicon carbide powder is in the range of 20% by weight or less. Although it is not always necessary to add carbon powder as a raw material, it is preferable that a carbon component is present. Even when carbon powder is not added, there is a slight amount of carbon because there is a carbon component that carbonizes from the resin. When the carbon component exceeds 20% by weight, the carbon reacts with Si to generate SiC. It is assumed that the strength cannot be sufficiently developed due to the influence of the volume expansion generated at this time.

  Next, heat treatment is performed on the bonded ceramic bonded body and the adhesive layer. Thereby, an adhesive bond layer is carbonized and it is set as a porous part. The porous part functions as a Si infiltration part. The heat treatment for making the adhesive layer porous is preferably performed at a temperature in the range of 300 ° C. to 2000 ° C. in a vacuum or in an inert gas atmosphere. The porosity of the porous portion can be selected within the range of the porosity used in a general reaction sintered body. In order to secure a supply path for molten Si, the porosity of the porous portion is preferably more than 20%. If the Si supply path is not secured, the amount of residual carbon increases at the joint. When the porosity of the porous portion exceeds 80%, the amount of free Si phase increases. Both of these are factors that reduce the strength of the joint.

  Next, the ceramic joined body and the porous portion are heated to a temperature equal to or higher than the melting point of Si, and the porous portion in the heated state is impregnated with molten Si. The porous part is heated to a temperature of 1400 ° C. or higher, and the porous part is impregnated with molten Si in a vacuum or in an inert atmosphere. The porous portion is reacted and sintered by such impregnation with molten Si to form the joint portion 30. A ceramic structure (joined body) is formed by such joining.

  It is also possible to simultaneously perform the heating step for forming the porous portion and the impregnation step. That is, the resin is carbonized in the temperature raising process up to 1400 ° C. to obtain a porous portion. Furthermore, by continuing heating and heating, the porous part can be subjected to reaction sintering to obtain a ceramic joined body.

  The carbon component and carbon powder derived from the resin present in the porous portion react with contact with molten Si at a high temperature to generate silicon carbide (SiC). Although the silicon carbide powder as a starting material hardly changes, in some silicon carbide powders, SiC produced by the reaction sintering covers the silicon carbide powder as a starting material. If the carbon itself becomes SiC, SiC particles having a small particle size are formed. Further, Si is continuously present as free Si in a network form in the gaps between these SiC particles.

  By applying the joining process as described above, a joined body of a plurality of ceramic workpieces having a joint including reactively sintered silicon carbide is obtained.

FIG. 21A to FIG. 21C are perspective views illustrating another ceramic structure according to the embodiment.
FIG. 21A illustrates ceramic joined bodies 10a to 10d before joining the ceramic structure 100a according to the embodiment. FIG. 21B is a perspective view of the ceramic structure 100a in which the ceramic bonded bodies 10a to 10d are bonded by the bonding portion 30a. FIG.21 (c) is a perspective view which shows the cross section of the ceramic structure 100a in the A3-A4 line | wire shown in FIG.21 (b).

  Each of the ceramic bonded bodies 10a to 10d has a box shape having an opening on the upper surface or the lower surface, and has a partition inside. Except for this, the same description as the first member 10 and the second member 20 described above can be applied to the ceramic bonded bodies 10a to 10d. Moreover, the description similar to the above-mentioned junction part 30 is applicable to the junction part 30a.

  The length of one side of the ceramic structure 100a is longer than 1 meter (m). As shown in FIG. 21B, the length L1 of the longest side E1 of the ceramic structure 100a is, for example, 1 m or more. Further, for example, the length L1 is not less than 1 and not more than 25 times the length L2 of the shortest side of the ceramic structure 100a.

  Moreover, the ceramic structure 100a has a plurality of spaces 60 surrounded by at least three surfaces. Each space 60 is closed, for example. One of the spaces 60 shown in FIG. 21C is surrounded by the surfaces f1 to f3.

  According to the embodiment, high bonding strength can be obtained, and variations in bonding strength can be suppressed. Thereby, a ceramic structure having a large shape, a high aspect ratio, and a complicated shape as shown in FIGS. 21A to 21C can be manufactured.

FIG. 22A and FIG. 22B are perspective views illustrating another ceramic structure according to the embodiment.
FIG. 22A illustrates ceramic bonded bodies 10e to 10h before bonding of the ceramic structure 100b according to the embodiment. FIG. 22B is a perspective view of the ceramic structure 100b in which the ceramic bonded bodies 10e to 10f are bonded by the bonding portion 30b.

  Each of the ceramic bonded bodies 10e to 10h has a box shape having an opening on the upper surface or the lower surface, and has a partition inside. Except for this, the same description as the first member 10 and the second member 20 described above can be applied to the ceramic bonded bodies 10e to 10h. Moreover, the description similar to the above-mentioned junction part 30 is applicable to the junction part 30b.

  As shown in FIG. 22B, the length L3 of one side (side E2) of the ceramic structure 100b is, for example, 1 m or more. For example, the length L3 is 1 to 25 times the length L4 of the other side of the ceramic structure 100b. The ceramic structure 100b has a plurality of spaces 61 surrounded by at least three surfaces. For example, one of the spaces 61 shown in FIG. 22B is surrounded by the surfaces f4 to f6. According to the embodiment, a ceramic structure having a large shape, a high aspect ratio, and a complicated shape can be manufactured.

The embodiment of the present invention has been described above. However, the present invention is not limited to these descriptions. As long as the features of the present invention are provided, those skilled in the art appropriately modified the design of the above-described embodiments are also included in the scope of the present invention. For example, the shape, size, material, arrangement, and the like of each element included in the first member 10, the second member 20, and the joint portion 30 are not limited to those illustrated, but can be changed as appropriate.
Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

  DESCRIPTION OF SYMBOLS 10 1st member, 10a-10h Ceramics to-be-joined body, 11, 12, 14, 15 joint surface, 20 2nd member, 30, 30a, 30b Joint part (interposition part), 30p 1st part, 30q 2nd part, 31 central layer, 32 side layer, 32a first side layer, 32b second side layer, 40a, 40b interface, 41-44 first to fourth interface, 51 first curved surface, 52 second curved surface, 60, 61 space, 71 SiC particles, 75 Si part, 100, 100a, 100b, 101 ceramic structure, 200 electron exposure device, 210 electron beam source, 220 stage, 230 electromagnetic lens, 240 deflector, 250 vacuum chamber, Da to Dc distance, L1 ~ L4 length, Lxs, Lzs chord length, R, RA region, R1-R3 observation region, S110-S17 Step, T, Tmax, Tmin thickness, Tave average thickness, W the processing object, f1 to f6 surface

Claims (17)

A first member comprising silicon and silicon carbide;
A second member containing silicon and silicon carbide;
An intervening portion interposed between the first member and the second member and including silicon and silicon carbide;
With
Ten observation regions each having a size of 128 μm × 128 μm are set in the cross section of the interposition part, the ratio of the area occupied by silicon in each of the ten observation regions of the interposition part is calculated, and the interposition part the average of the ratio as a in 10 locations,
Ten observation regions each having a size of 128 μm × 128 μm are set in the cross section of the first member, and the ratio of the area occupied by silicon in each of the ten observation regions of the first member is calculated. the average of the percentage of the 10 locations 1 member and B1,
Ten observation regions having a size of 128 μm × 128 μm are set in the cross section of the second member, and the ratio of the area occupied by Si in each of the ten observation regions of the second member is calculated. When the average of the ratio of the 10 points of the two members and B2,
Wherein A, the B1 and the B2 is 1.0 <A / B1 <1.3, and 1.0 <meets at least one of A / B2 <1.3,
The standard deviation of the ratio at the ten locations of the interposition part is C,
The standard deviation of the ratio at the 10 locations of the first member is D1,
When the standard deviation of the ratio at the ten locations of the second member is D2,
Wherein C, the D1 and the D2 are, 1.3 <C / D1 <3.3, and a ceramic structure, wherein 1.3 <C / D2 <Succoth meet at least one of 3.3 . Wherein A is a ceramic structure according to claim 1 Symbol mounting, characterized in that 30% or less than 23%. The interposition part is
The middle layer,
A first side layer located between the central layer and the first member;
A second side layer located between the central layer and the second member;
Including
Of the cross section of the first side surface layer, to the area of the size of the area of 65μm × 252μm, the ratio of the area of the silicon contained in the region of the first side layer, and E1,
Of the cross section of the second side surface layer, to the area of the size of the area of 65μm × 252μm, the ratio of the area of the silicon contained in the region of the second side layer, and E2,
Among the cross-section of the central layer, to the area of the size of the area of 65μm × 252μm, the ratio of the area of the silicon contained in the region of the central layer, when F,
The ceramic structure according to claim 1 or 2, wherein at least one of the E1 and the E2 is lower than the F. The ceramic structure according to claim 3 , wherein the E1, the E2, and the F satisfy at least one of E1 / F <0.95 and E2 / F <0.95. The cross section of the central layer is a cross section in a plane including a first direction perpendicular to the interface between the first member and the interposition part and a second direction parallel to the interface;
In the cross section of the central layer, the central layer includes a plurality of silicon spots;
In each of the plurality of silicon spots, an average value of the chord lengths in the first direction is calculated, and a maximum value of the average values of the chord lengths in the first direction in the plurality of silicon spots is Lx,
In each of the plurality of silicon spots, an average value of the chord lengths in the second direction is calculated, and a maximum value of the average values of the chord lengths in the second direction is Lz. ,
The ceramic structure according to claim 3 or 4 , wherein the Lx is smaller than the Lz . The ceramic structure according to claim 5 , wherein a ratio of the Lx to the Lz is less than 0.9. The ceramic structure according to any one of claims 1 to 6 , wherein an average thickness of the interposition part is not less than 100 micrometers and not more than 400 micrometers. The ceramic structure according to claim 7 , wherein a difference between a maximum value of the thickness of the interposition part and a minimum value of the thickness of the interposition part is 100 micrometers or less. The interface between the first member and the interposition part is
A first interface;
A second interface inclined with respect to the first interface;
Have
The interface between the second member and the interposition part is
A third interface facing the first interface via the interposition part;
A fourth interface inclined with respect to the third interface and facing the second interface via the interposition part;
Have
The ceramic structure according to any one of claims 1 to 8 , wherein the first interface and the second interface are located between the third interface and the fourth interface. The interface between the first member and the interposition part has a first curved surface that connects the first interface and the second interface;
10. The ceramic structure according to claim 9 , wherein an interface between the second member and the interposition part has a second curved surface connecting the third interface and the fourth interface. In a cross section in a plane including a direction perpendicular to the first interface and a direction perpendicular to the third interface, the radius of curvature of the first curved surface is smaller than the radius of curvature of the second curved surface. ceramic structure according to claim 1 0, characterized in that. The distance between the first curved surface and the second curved surface is shorter than the distance between the first interface and the third interface, and is shorter than the distance between the second interface and the fourth interface. ceramic structure according to claim 1 0 or 1 1, wherein the shorter. The ceramic structure according to any one of claims 1 to 12 , wherein a Weibull coefficient calculated from a bending strength of the ceramic structure is 10 or more. The open porosity in the intermediate portion, the ceramic structural body according to any one of claims 1 to 1 3, characterized in that 0.1% or less. The volume resistivity of the ceramic structure, 2.0 × 10 ^-2, wherein the ohm-cm or less claims 1 to 1 4 ceramic structure according to any one of. At least one side is longer than 1 meter,
Ceramic structure according to any one of claims 1 to 1 5, characterized in that it comprises a plurality of inter-sky surrounded by at least three faces. A structural member for a semiconductor manufacturing apparatus, comprising the ceramic structure according to any one of claims 1 to 16 .