CERAMIC SUSCEPTOR AND SiC BASE MEMBER

Abstract

To provide a technique for joining AlN and SiC ceramic members, which are two mutually different ceramic members, and also to provide a ceramic susceptor and a SiC base member having a primary surface with low warpage and high dimensional accuracy.SOLUTION: A ceramic susceptor 100 comprises a plate-shaped AlN ceramic member 110 primarily composed of AlN, and a plate-shaped SiC composite material 120 primarily composed of SiC. The SiC composite material 120 contains 30 wt.% to 49 wt.% of a metal boride. The average difference in thermal linear expansion coefficient between the average linear expansion coefficient of the AlN ceramic member 110 at 800°C and the average linear expansion coefficient of the SiC composite material 120 at 800°C is 0.2 ppm / K or less.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a ceramic susceptor and a SiC substrate member. [Background technology]

[0002] Patent Document 1 discloses a bonded body having a wafer mounting surface for holding a substrate such as a wafer. The bonded body described in Patent Document 1 is a bonded body of an upper plate and a lower plate made of the same ceramic material, and an intermediate plate disposed between the upper plate and the lower plate. The intermediate plate has a larger coefficient of linear expansion (CTE) than the upper plate and the lower plate. In Patent Document 1, the upper plate and the lower plate made of the same ceramic material are bonded via the intermediate plate having a larger CTE than the upper plate and the lower plate to produce a bonded body having a wafer mounting surface with high dimensional accuracy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-92824 A Summary of the Invention [Problem to be solved by the invention]

[0004] When joining two different types of ceramic members, such as an AlN ceramic member and a SiC ceramic member, the technique disclosed in Patent Document 1 cannot be applied as is.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a technique for joining two different types of ceramic members, an AlN ceramic member and a SiC ceramic member, and to provide a ceramic susceptor and a SiC substrate member having main surfaces with little warping and high dimensional accuracy. [Means for solving the problem]

[0006] According to an aspect of the present invention, there is provided an AlN ceramic member having an upper surface and a lower surface facing the upper surface in a vertical direction, the AlN ceramic member being mainly composed of AlN; The present invention provides a ceramic susceptor comprising: a plate-shaped SiC composite material having a main surface joined to the upper surface or the lower surface of the AlN ceramic member, containing SiC as a main component and containing 30 wt% to 49 wt% of a metal boride, and having an average linear expansion coefficient whose difference from the average linear expansion coefficient of the AlN ceramic member at 800°C is 0.2 ppm / K or less. Effect of the Invention

[0007] According to the configuration of the present invention, the SiC composite contains 30wt% to 49wt% of metal boride. The difference in average thermal expansion coefficient between the average thermal expansion coefficient of the AlN ceramic member at 800°C and the average thermal expansion coefficient of the SiC composite at 800°C is 0.2ppm / K or less. In this case, it is possible to suppress the occurrence of cracks after bonding the AlN ceramic member and the SiC composite. Also, it is possible to suppress warping of the upper surface of the AlN ceramic member. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a ceramic susceptor 100. As shown in FIG. [Diagram 2] FIG. 2 is a schematic explanatory diagram of the ceramic susceptor 100. As shown in FIG. [Diagram 3] 1(a) to 1(d) are diagrams illustrating a flow of a method for manufacturing the AlN ceramic member 110. [Figure 4] FIG. 4 is a flowchart showing a method for manufacturing the SiC composite material 120. [Diagram 5] FIG. 5 is a table summarizing the results of Examples 1 to 4. [Figure 6] FIG. 6 is a table summarizing the results of Examples 5 to 7. [Figure 7] FIG. 7 is a table summarizing the results of Comparative Examples 1 to 3. [Figure 8] FIG. 8 is a schematic explanatory view of the SiC substrate member 120A.

DETAILED DESCRIPTION OF THE INVENTION

[0009] <Ceramic susceptor 100> The ceramic susceptor 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The ceramic susceptor 100 according to the present embodiment is used, for example, as a stage for holding a semiconductor wafer such as a silicon wafer (hereinafter simply referred to as wafer 10) inside a semiconductor manufacturing apparatus. Further, when an electrode 140 (see FIG. 2) is embedded in the ceramic susceptor 100 as described later, it can also be used as a heater for heating the wafer 10. In the following description, the vertical direction 5 is defined based on the state in which the ceramic susceptor 100 is installed so as to be usable (the state in FIG. 1). As shown in FIG. 1, the ceramic susceptor 100 according to the present embodiment includes an AlN ceramic member 110, a SiC composite material 120, and an electrode 140 (see FIG. 2).

[0010] <AlN ceramic member 110> The AlN ceramic member 110 is a member having a circular plate shape with a diameter of 200 mm or more and a thickness (length in the vertical direction 5) of 2 mm to 50 mm. The wafer 10 is placed on the upper surface 111 of the AlN ceramic member 110. In FIG. 1, the wafer 10 and the AlN ceramic member 110 are shown separated from each other for easy viewing of the drawing. The AlN ceramic member 110 is formed of AlN ceramics containing AlN as a main component. Here, the AlN ceramics containing AlN as a main component refers to a ceramic sintered body containing 50 wt% or more of AlN.

[0011] <Electrode 140> As shown in FIG. 2, an electrode 140 is embedded at a position 0.05 mm or more below the upper surface 111 of the AlN ceramic member 110. As shown in FIG. 2, the electrode 140 is a metal mesh or foil cut in a strip shape. The outer diameter of the electrode 140 is slightly smaller than the outer diameter of the AlN ceramic member 110, and the electrode 140 does not protrude from the side surface of the AlN ceramic member 110. A terminal portion 141 connected to a power supply line (not shown) is provided at approximately the center of the electrode 140. The electrode 140 is formed of a heat-resistant metal (high melting point metal) such as a mesh or foil woven from wires of an alloy containing tungsten (W), molybdenum (Mo), molybdenum and / or tungsten. The purity of tungsten and molybdenum is preferably 99% or more. The thickness of the electrode 140 is 0.15 mm or less. From the viewpoint of increasing the resistance value of the electrode 140 and reducing the consumption current, it is preferable that the wire diameter of the wire is 0.1 mm or less and the thickness of the electrode 140 is 0.1 mm or less. Further, the width of the electrode 140 cut in a strip shape is preferably 2.5 mm to 20 mm, and more preferably 5 mm to 15 mm. In the present embodiment, the electrode 140 is cut into the shape shown in FIG. 2, but the shape of the electrode 140 is not limited to this and can be changed as appropriate. In addition to the electrode 140, or instead of the electrode 140, an electrostatic adsorption electrode or a plasma electrode for generating plasma may be embedded above the AlN ceramic member 110 inside the AlN ceramic member 110. Further, the electrode 140 does not necessarily have to be embedded in the AlN ceramic member 110. For example, the electrode 140 may be embedded in the SiC composite material 120. Alternatively, the electrode 140 may be embedded in both the AlN ceramic member 110 and the SiC composite material 120.

[0012] <SiC composite material 120> The SiC composite material 120 is formed of SiC ceramics containing SiC as a main component, and has a circular plate shape. The SiC ceramics containing SiC as a main component is a ceramic sintered body containing 50 wt% or more of SiC. In this case, the balance contains sintering aid components such as B and C, as well as 20 to 49 wt% of metal borides. For example, borides of metals in groups 4 to 6 of the periodic table can be used as the metal borides. There is no particular limit to the size of the SiC composite material 120, but it can have a diameter of 150 mm or more and a thickness of 20 mm to 50 mm because of its use as a substrate holding member for semiconductor manufacturing equipment. As shown in FIGS. 1 and 2, the SiC composite material 120 is disposed below the AlN ceramic member 110. The SiC composite material 120 may be disposed above the AlN ceramic member 110.

[0013] A hollow flow path F is formed inside the SiC composite 120. As described later, the SiC composite 120 is formed by bonding an upper plate 122 and a lower plate 126 (see FIG. 2) together. A groove 124 is formed on at least one of the lower surface 122b (surface facing the lower plate 126) of the upper plate 122 and the upper surface 126a (surface facing the upper plate 122) of the lower plate 126, and then the upper plate 122 and the lower plate 126 are bonded together in a superposed state, thereby forming a hollow flow path F inside the SiC composite 120. The shape of the flow path F can be any shape. For example, the flow path F may be a substantially spiral shape when viewed from above. The cross-sectional shape of the flow path F can also be any shape. For example, the cross-sectional shape of the flow path F may be rectangular or circular.

[0014] The metal borides contained in the SiC composite 120 are evenly dispersed in the SiC structure. 2 In the SiC composite 120 to which TiB was added, 2 The particle size (hereinafter, TiB 2 The ratio of the particle diameter of the TiB2 particles (hereinafter referred to as the SiC particle diameter) to the particle diameter of the SiC particles (hereinafter referred to as the SiC particle diameter) is 0.3 to 1.0 (0.3≦TiB 2Particle size / SiC particle size≦1.0). The particle size is an average particle size calculated using an appropriate evaluation method. For example, it is an average particle size calculated by the intercept method. The intercept method involves drawing any straight lines (called scanning lines) at equal intervals in parallel in the structure of a crystal aggregate, measuring the lengths of the line segments cut by the scanning lines at the grain boundaries, and determining the average particle size from the distribution of these lengths (intercept diameters). Alternatively, the particles in a specified region (for example, a rectangular region with one side of 50 μm) may be approximated as an ellipse, and the average particle size may be determined by averaging the lengths of the major axes.

[0015] <Method for manufacturing ceramic susceptor 100> Next, a description will be given of a manufacturing method of the ceramic susceptor 100. For the sake of simplicity, it is assumed that the electrode 140 is embedded in the AlN ceramic member 110, but not in the SiC composite material 120.

[0016] The manufacturing method of the ceramic susceptor 100 includes preparing a plate-shaped AlN ceramic member 110 mainly composed of AlN, preparing a plate-shaped SiC composite material 120 mainly composed of SiC, and joining the AlN ceramic member 110 and the SiC composite material 120.

[0017] First, a method for manufacturing the AlN ceramic member 110 will be described. As shown in Fig. 3(a), granulated powder P mainly composed of aluminum nitride (AlN) powder is charged into a bed-equipped carbon mold 601 and pre-pressed with a punch 602. The granulated powder P contains 7 wt% or less of a sintering aid (for example, Y 2 O 3 3(b), an electrode 140 cut into a predetermined shape is placed on the pre-pressed granulated powder P. The electrode 140 is placed parallel to a surface perpendicular to the pressing direction (the bottom surface of the bed-equipped mold 601). At this time, a pellet of W or a pellet of Mo may be embedded at the position of the terminal 141 (see FIG. 3) of the electrode 140.

[0018] As shown in FIG. 3(c), granulated powder P is further poured into bed mold 601 so as to cover electrode 140, and pressed and molded with punch 602. Next, as shown in FIG. 3(d), granulated powder P with electrode 140 embedded therein is fired in a pressed state. The pressure applied during firing is preferably 1 MPa or more. Also, firing is preferably performed at a temperature of 1800°C or more. After firing, a blind hole is drilled up to electrode 140, not shown, in order to insert a power supply line for supplying power to terminal 141 of electrode 140. If a pellet is embedded, a blind hole may be drilled up to the pellet.

[0019] Next, a method for manufacturing the SiC composite material 120 will be described with reference to FIG. 4. The SiC composite material 120 includes an upper plate 122 and a lower plate 126. First, a predetermined amount of metal boride is added to the SiC raw material powder. Furthermore, 4 wt % or less of a sintering aid (B 4 C, C) are added. For example, 20 to 49 wt % of metal boride can be added. As described later, by adding metal boride, the CTE (coefficient of linear thermal expansion) value of the SiC composite material 120 can be adjusted to be close to the CTE value of the AlN ceramic member 110. A PVA (polyvinyl alcohol) binder is added to the SiC raw material powder to which the metal boride has been added, and the mixture is mixed in ethanol and dried, and then granulated into granules to produce granulated powder Q containing SiC as a main component (S101). Note that when producing the granulated powder Q, the addition rate of the metal boride can be the same for the granulated powder Q for producing the upper plate 122 and the granulated powder Q for producing the lower plate 126, but can also be different. For example, when the upper plate 122 and the AlN ceramic member 110 are joined together, in order to suppress the difference in the average linear expansion coefficient between them, when preparing the granulated powder Q for manufacturing the upper plate 122, 35 to 49 wt % of TiB 2 Also, TiB 2 When the addition rate is high (e.g., 35 to 49 wt%), hot press sintering is required, but TiB 2When the additive rate of TiB is low (for example, 20 wt % or less), atmospheric sintering is possible. When atmospheric sintering is possible, atmospheric sintering can be performed after grooves 124 are formed in the green body before sintering, so that the manufacturing cost of lower plate 126 having grooves 124 formed therein can be reduced. Therefore, in order to make it easier to form grooves 124 on upper surface 126a of lower plate 126, TiB is added at a lower additive rate (for example, 20 wt %) than upper plate 122 when granulated powder Q for manufacturing lower plate 126 is prepared. 2 can be added.

[0020] Next, the granulated powder Q is filled into a rubber mold and isostatically pressurized (CIP) by water pressure to produce a CIP molded body that will become the upper plate 122 and a CIP molded body that will become the lower plate 126 (S102). For example, CIP molding can be performed at a pressure of 130 MPa. Next, the CIP molded body is degreased to remove the binder. Thereafter, the degreased CIP molded body is heat treated in a vacuum atmosphere at a temperature of 1500°C for 2 hours, and then fired at normal pressure in an Ar atmosphere at a temperature of 2000°C or higher for 3 hours (S103). Alternatively, the CIP molded body may be placed in a bedded mold 601 made of carbon and hot-press fired while pressed with a punch 602. For example, hot-press firing can be performed in an Ar atmosphere at a temperature of 2000°C or higher for 3 hours (S103). The firing time is not necessarily limited to 3 hours. The firing time is preferably 0.1 to 10 hours, and more preferably 1 to 5 hours.

[0021] However, the method is not necessarily limited to producing a CIP molded body and firing the produced CIP molded body. As in the above-mentioned method for producing the AlN ceramic member 110, the granulated powder Q may be placed in a bedded carbon mold 601 and hot-press fired in a state pressed with a punch 602. For example, the hot-press firing may be performed for 3 hours at a temperature of 2000° C. or higher in an Ar atmosphere.

[0022] Next, the sintered body is externally processed to produce the upper plate 122 and the lower plate 126 (S104). At this time, grooves 124 (see FIG. 2) that will later become the flow paths F are formed in the upper surface 126a of the lower plate 126 and / or the lower surface 122b of the upper plate 122. Note that the grooves 124 do not necessarily have to be formed in the sintered body. The grooves 124 can also be formed in the calcined body before the main sintering or in the CIP molded body. As described above, when the lower plate 126 is sintered by normal pressure sintering, it is preferable to form the grooves 124 in the calcined body before the main sintering or in the CIP molded body.

[0023] Next, a description will be given of a method for joining the SiC composite material 120 (upper plate 122) and the AlN ceramic member 110. Note that the method for joining the upper plate 122 and the lower plate 126 is similar to this, so the description will be omitted.

[0024] The SiC composite material 120 and the AlN ceramic member 110 can be bonded by diffusion bonding at a temperature of 1500°C or higher and a pressure of 1 MPa or higher. In this case, it is not necessary to interpose a bonding material between the SiC composite material 120 and the AlN ceramic member 110. The absence of a bonding material means that no bonding layer is observed at an optical microscope level (magnification of about 500 times). Therefore, the upper plate 122 and the lower plate 126 can be bonded in a state of direct contact. When the SiC composite material 120 and the AlN ceramic member 110 are bonded by diffusion bonding, the center line average roughness Ra of the bonding surface before bonding is preferably 0.2 μm or less, and more preferably 0.1 μm or less.

[0025] The SiC composite material 120 and the AlN ceramic member 110 can be joined by hard brazing. The hard brazing is a brazing material having a melting point (including liquidus temperature and glass transition temperature) of 450°C or more. By heating the SiC composite material 120 and the AlN ceramic member 110 to a temperature of 450°C or more while the hard brazing material is interposed between them, the SiC composite material 120 and the AlN ceramic member 110 can be joined by the fluidized hard brazing material or the molten hard brazing material. At this time, the heat joining is performed while a load of 0.001 MPa or more is applied. The atmosphere can be appropriately selected from air, inert gas, and vacuum. For example, silver brazing (BAg-8, melting point 780°C), aluminum brazing (A4047, eutectic point 577°C), gold brazing (BAu-4, liquidus temperature 950°C), nickel brazing (BNi-2, liquidus temperature 1000°C), etc. can be used as the hard brazing material. These brazing materials may contain active metals such as Ti, Hf, and Zr. Metal foils such as Al foils may also be used as the brazing materials. When the SiC composite material 120 and the AlN ceramic member 110 are joined by brazing, it is preferable that the center line average roughness Ra of the joining surfaces before joining is 1.6 μm or less.

[0026] The SiC composite material 120 and the AlN ceramic member 110 can be joined by soft soldering. The soft solder is a solder material having a melting point (including liquidus temperature and glass transition temperature) of less than 450°C. The SiC composite material 120 and the AlN ceramic member 110 can be joined by the fluidized soft solder material or the molten soft solder material by heating to a temperature of less than 450°C with the soft solder material interposed between them. At this time, the heat joining is performed with a load of 0.001 MPa or more applied. The atmosphere can be appropriately selected from air, inert gas, and vacuum. In addition, for example, In, Sn, Pb, and alloys (solder) thereof can be used as the soft solder material. When the SiC composite material 120 and the AlN ceramic member 110 are joined by soft soldering, it is preferable that the center line average roughness Ra of the joining surface before joining is 1.6 μm or less.

[0027] The joining method of the SiC composite material 120 and the AlN ceramic member 110 is not limited to the above-mentioned diffusion joining, hard soldering, and soft soldering, and known anodic joining or the like can also be used.

[0028] Next, the evaluation of the coefficient of thermal expansion (hereinafter referred to as CTE) will be described. CTE indicates the rate at which the length of an object expands due to a temperature increase per degree of temperature. Since CTE is not always a constant value, it is represented by the average value (average coefficient of linear expansion) within a certain temperature range. The length L of the object at room temperature 0 and the temperature difference ΔT between the temperatures T 1 and T 2 and the difference in length ΔL of the object between the temperatures T 1 and T 2 are used, and the average coefficient of linear expansion α between the temperatures T 1 and T 2 is expressed as α = ΔL / (L 0 × ΔT).

[0029] In addition, the inventors have found that when producing the SiC composite material 120, by adding a metal boride to the SiC raw material powder, the value of the CTE (average coefficient of linear expansion) of the SiC composite material 120 can be adjusted to be close to the value of the CTE (average coefficient of linear expansion) of the AlN ceramic member 110. And when joining the SiC composite material 120 produced by adding a metal boride to the AlN ceramic member 110, it has been found that it is preferable that the difference Δ in the average coefficient of linear expansion at 800 °C is 0.2 ppm / K or less. Also, when the addition rate of the metal boride is different between the upper plate 122 and the lower plate 126 constituting the SiC composite material 120, it has been found that it is preferable that the difference Δ in the average coefficient of linear expansion at 800 °C between the upper plate 122 and the lower plate 126 is 0.5 ppm / K or less.

Example

[0030] The present invention will be further described below using Examples 1 to 7 and Comparative Examples 1 to 3. However, the present invention is not limited to the Examples described below. Note that Fig. 5 shows a table summarizing the results of Examples 1 to 4, Fig. 6 shows a table summarizing the results of Examples 5 to 7, and Fig. 7 shows a table summarizing the results of Comparative Examples 1 to 3.

[0031] [Example 1] A ceramic susceptor 100 (see FIG. 2) of Example 1 will be described. In Example 1, 5 wt % of a sintering aid (Y 2 O 3 A disk-shaped AlN ceramic member 110 having a diameter of 150 mm and a thickness of 10 mm was fabricated by the above-mentioned manufacturing method using aluminum nitride (AlN) to which ZnO was added as a raw material. Note that no electrode 140 was embedded in the AlN ceramic member 110 of Example 1.

[0032] TiB as metal boride 2 Using silicon carbide (SiC) doped with TiB as a raw material, a disk-shaped upper plate 122 having a diameter of 150 mm and a thickness of 5 mm and a disk-shaped lower plate 126 having a diameter of 150 mm and a thickness of 30 mm were manufactured by the above-mentioned manufacturing method. Both the upper plate 122 and the lower plate 126 were hot-pressed for 3 hours at a temperature of 2000°C or higher in an Ar atmosphere. When manufacturing the lower plate 126, a plurality of concentric grooves 124 (see FIG. 2) that will later become the flow paths F were formed in the CIP molded body before sintering. The TiB 2 The addition rate of TiB in the lower plate 126 was set at 47 wt%. 2 The addition rate was also set at 47 wt%.

[0033] In Example 1, the upper plate 122 and the lower plate 126 were bonded by diffusion bonding at a temperature of 1800° C. to produce the SiC composite material 120. In addition, the SiC composite material 120 and the AlN ceramic member 110 were hard brazed at a temperature of 600° C. with an Al foil sandwiched between them to produce the ceramic susceptor 100.

[0034] In Example 1, the relative density of the upper plate 122 was 95.7%, and the thermal conductivity was 91 W / mK. The relative density is the ratio of the bulk density of the upper plate 122 to the theoretical density calculated from the composition of the upper plate 122, and complies with the water displacement method (Archimedes' method) JIS R1634, JIS C2141.

[0035] Using Thermo plus TMA8310 manufactured by Rigaku, the average linear expansion coefficient α of the AlN ceramic member 110 at 20°C to 800°C 1 and the average linear expansion coefficient β of the upper plate 122 at 20°C to 800°C 1 and the average linear expansion coefficient β of the lower plate 126 at 20°C to 800°C 2 were each measured. Based on the measurement results, the absolute value of the difference Δ in the average linear expansion coefficient between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C 1 (|α 1 -β 1 |) and the absolute value of the difference Δ in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20°C to 800°C 2 (|β 1 -β 2 |) were calculated. The measurement method for the average linear expansion coefficient complied with JIS R1618 and JIS Z2285. In the following description, the absolute value of the difference in the average linear expansion coefficient is simply referred to as the difference in the average linear expansion coefficient (or CTE difference).

[0036] In Example 1, the difference Δ in the average linear expansion coefficient between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C 1 was 0.05 ppm / K. The difference Δ in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20°C to 800°C 2 was 0 ppm / K.

[0037] In Example 1, the ceramic susceptor 100 was visually inspected for cracks to check the bonding state. For those without cracks, the warpage of the upper surface 111 of the AlN ceramic member 110 was measured, and a warpage of less than 0.1 mm per 150 mm diameter was evaluated as ⊚, a warpage of 0.1 mm or more and less than 0.5 mm was evaluated as ◯, and a warpage of 0.5 mm or more was evaluated as x. In Example 1, no cracks were observed in the ceramic susceptor 100. The warpage of the upper surface 111 of the AlN ceramic member 110 was evaluated as ⊚.

[0038] [Example 2] The ceramic susceptor 100 of Example 2 has a TiB 2 The SiC composite material 120 was produced by the same manufacturing method as the ceramic susceptor 100 of Example 1, except that the additive rate of was 35 wt% and that an Al foil was sandwiched between the upper plate 122 and the lower plate 126 and hard soldered at a temperature of 600°C to produce the SiC composite material 120. In Example 2, the relative density of the upper plate 122 was 95.7%, and the thermal conductivity was 91 W / mK. The difference in the average linear expansion coefficient Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0.2 ppm / K.

[0039] In Example 2, no cracks were observed in the ceramic susceptor 100. The evaluation of the warpage of the upper surface 111 of the AlN ceramic member 110 was rated as ⊚. 2 By setting the addition rate of TiB to 47 wt %, it is possible to suppress the difference in the average linear expansion coefficient between the upper plate 122 and the AlN ceramic member 110, and it is possible to suppress the stress between the upper plate 122 and the AlN ceramic member 110. 2 By setting the addition rate at 35 wt %, the thermal conductivity could be improved to 107 W / mK compared to the upper plate 122, and the thermal conductivity of the entire SiC composite material 120 could be further increased.

[0040] [Example 3] The ceramic susceptor 100 of Example 3 has a TiB 2 The SiC composite material 120 was produced by the same manufacturing method as that of the ceramic susceptor 100 of Example 1, except that the additive rate of was 20 wt%, the lower plate 126 was sintered at normal pressure at a temperature of 2150°C, and the upper plate 122 and the lower plate 126 were hard soldered at a temperature of 600°C with Al foil sandwiched between them. In Example 3, the relative density of the upper plate 122 was 95.7%, and the thermal conductivity was 91 W / mK. The difference in the average linear expansion coefficient Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0.5 ppm / K.

[0041] In Example 3, no cracks were found in the ceramic susceptor 100. The evaluation of the warpage of the upper surface 111 of the AlN ceramic member 110 was ◯. 2 By setting the addition rate of TiB to 47 wt %, it is possible to suppress the difference in the average linear expansion coefficient between the upper plate 122 and the AlN ceramic member 110, and it is possible to suppress the stress between the upper plate 122 and the AlN ceramic member 110. 2 By setting the TiB content at 20 wt %, the lower plate 126 could be sintered at atmospheric pressure. Therefore, as described above, it became easier to process the grooves 124 in the lower plate 126, and the manufacturing cost could be reduced. 2 By setting the additive rate at 20 wt %, the thermal conductivity could be improved to 165 W / mK compared to the upper plate 122, and the thermal conductivity of the entire SiC composite material 120 could be further increased.

[0042] [Example 4] The ceramic susceptor 100 of Example 4 has a TiB 2The addition rate of TiB in the lower plate 126 is 35 wt%. 2 The ceramic susceptor 100 of Example 4 was manufactured by the same manufacturing method as that of the ceramic susceptor 100 of Example 1, except that the additive rate of was 35 wt %. In Example 4, the relative density of the upper plate 122 was 96.2%, and the thermal conductivity was 107 W / mK. The difference in the average linear expansion coefficient Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0 ppm / K.

[0043] In Example 4, no cracks were found in the ceramic susceptor 100. The warpage of the upper surface 111 of the AlN ceramic member 110 was evaluated as ◯.

[0044] [Example 5] The ceramic susceptor 100 of Example 5 has a TiB 2 The addition rate of TiB in the lower plate 126 is 35 wt%. 2 The SiC composite material 120 was produced by the same manufacturing method as the ceramic susceptor 100 of Example 1, except that the additive rate was 20 wt%, the lower plate 126 was sintered at normal pressure at a temperature of 2150°C, and the upper plate 122 and the lower plate 126 were hard soldered at a temperature of 600°C with Al foil sandwiched between them. In Example 5, the relative density of the upper plate 122 was 96.2%, and the thermal conductivity was 107 W / mK. The difference in the average linear expansion coefficient Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0.3 ppm / K.

[0045] In Example 5, no cracks were found in the ceramic susceptor 100. The evaluation of the warpage of the upper surface 111 of the AlN ceramic member 110 was ◯. In Example 5, as in Example 3, the TiB 2By setting the TiB content at 20 wt %, the lower plate 126 could be sintered at atmospheric pressure. Therefore, as described above, it became easier to process the grooves 124 in the lower plate 126, and the manufacturing cost could be reduced. 2 By increasing the addition rate to 20 wt %, the thermal conductivity of the upper plate 122 was 107 W / mK and the thermal conductivity of the lower plate 126 was 165 W / mK, and the thermal conductivity of the entire SiC composite material 120 was further increased.

[0046] [Example 6] The ceramic susceptor 100 of Example 6 was fabricated using NbB 2 30 wt% was added, and NbB 2 The SiC composite material 120 was produced by the same manufacturing method as the ceramic susceptor 100 of Example 1, except that 30 wt% of AlN was added, the upper plate 122 and the lower plate 126 were hot-pressed and fired at a temperature of 2125°C, and an Al foil was sandwiched between the upper plate 122 and the lower plate 126 and hard soldered at a temperature of 600°C to produce the SiC composite material 120. In Example 6, the relative density of the upper plate 122 was 96.7%, and the thermal conductivity was 101 W / mK. The difference in the average linear expansion coefficient Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0 ppm / K.

[0047] In Example 6, no cracks were observed in the ceramic susceptor 100. The evaluation of the warpage of the upper surface 111 of the AlN ceramic member 110 was ◯. In addition, NbB 2 By adding the metal boride, the thermal conductivity of the upper plate 122 became 101 W / mK, and the thermal conductivity of the lower plate 126 became 101 W / mK, thereby improving the thermal conductivity of the entire SiC composite 120. It was thus inferred that the boron component of the metal boride contributed to the densification of the SiC composite.

[0048] [Example 7] The ceramic susceptor 100 of Example 7 was produced by the same manufacturing method as the ceramic susceptor 100 of Example 5, except that the electrode 140 was embedded in the AlN ceramic member 110. In Example 7, the upper plate 122 had a relative density of 96.2% and a thermal conductivity of 107 W / mK, similar to Example 5. The difference in the average linear expansion coefficient Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0.3 ppm / K. In Example 7, similarly to Example 5, no cracks were found in the ceramic susceptor 100, and the warpage of the upper surface 111 of the AlN ceramic member 110 was evaluated as good.

[0049] In Example 7, a power supply terminal was connected to the electrode 140, and a heating test was performed up to 350° C. As a result of the heating test, it was found that the ceramic susceptor 100 of Example 7 was able to function as a heater for heating a substrate.

[0050] In the ceramic susceptors 100 of Examples 1 to 7, the relative density of the SiC composite 120 could be set to 95% or more, and a dense SiC composite 120 could be formed. 2 is evenly distributed in the SiC structure, and TiB 2 The ratio of the particle size to the SiC particle size is 0.3 to 1.0 (0.3≦TiB 2 It was found that the ratio of SiC particle diameter to SiC particle diameter was ≦1.0.

[0051] [Comparative Example 1] The ceramic susceptor 100 of Comparative Example 1 was manufactured by the same manufacturing method as the ceramic susceptor 100 of Example 1, except that 40 wt% of TiC was added when the upper plate 122 was manufactured, 40 wt% of TiC was added when the lower plate 126 was manufactured, the upper plate 122 and the lower plate 126 were hot-pressed and fired at a temperature of 2125°C, and the upper plate 122 and the lower plate 126 were hard soldered at a temperature of 600°C with an Al foil sandwiched between them to manufacture the SiC composite material 120. In Comparative Example 1, the relative density of the upper plate 122 was 84.1%, and the thermal conductivity was 79 W / mK. The average linear expansion coefficient difference Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0 ppm / K.

[0052] In the ceramic susceptor 100 of Comparative Example 1, the relative density of the SiC composite 120 was less than 95%, and it was not possible to form a dense SiC composite 120. No cracks were found in the ceramic susceptor 100, and the warpage of the upper surface 111 of the AlN ceramic member 110 was evaluated as good.

[0053] [Comparative Example 2] The ceramic susceptor 100 of Comparative Example 2 was produced by the same manufacturing method as the ceramic susceptor 100 of Example 1, except that 35 wt% of TiN was added when producing the upper plate 122, and 35 wt% of TiN was added when producing the lower plate 126, the upper plate 122 and the lower plate 126 were sintered at normal pressure at a temperature of 2125°C, and the upper plate 122 and the lower plate 126 were hard soldered at a temperature of 600°C with Al foil sandwiched between them to produce the SiC composite material 120. In Comparative Example 2, the relative density of the upper plate 122 was 49.0%, and the thermal conductivity was 48 W / mK. The average linear expansion coefficient difference Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0 ppm / K.

[0054] In the ceramic susceptor 100 of Comparative Example 2, the relative density of the SiC composite 120 was less than 95%, and it was not possible to form a dense SiC composite 120. No cracks were found in the ceramic susceptor 100, and the warpage of the upper surface 111 of the AlN ceramic member 110 was evaluated as excellent.

[0055] [Comparative Example 3] In the ceramic susceptor 100 of Comparative Example 3, ZrB 2 The lower plate 126 was prepared by adding 49 wt% of ZrB 2 The SiC composite material 120 was produced by the same manufacturing method as the ceramic susceptor 100 of Example 1, except that 49 wt% of AlN was added, the upper plate 122 and the lower plate 126 were hot-pressed and fired at a temperature of 2125°C, and an Al foil was sandwiched between the upper plate 122 and the lower plate 126 and hard soldered at a temperature of 600°C to produce the SiC composite material 120. In Comparative Example 3, the relative density of the upper plate 122 was 90.0%, and the thermal conductivity was 84 W / mK. The difference in the average linear expansion coefficient Δ between the AlN ceramic member 110 and the upper plate 122 at 20°C to 800°C was 1 The difference in the average linear expansion coefficient between the upper plate 122 and the lower plate 126 at 20° C. to 800° C., Δ 2 was 0 ppm / K.

[0056] In the ceramic susceptor 100 of Comparative Example 3, the relative density of the SiC composite 120 was less than 95%, and it was not possible to form a dense SiC composite 120. Cracks were confirmed in the ceramic susceptor 100, and the warpage of the upper surface 111 of the AlN ceramic member 110 was evaluated as ×.

[0057] <Effects of the embodiment> In the above embodiment and examples 1 to 7, the ceramic susceptor 100 includes a plate-shaped AlN ceramic member 110 mainly composed of AlN, and a plate-shaped SiC composite material 120 mainly composed of SiC. "Mainly composed of AlN (or SiC)" means that the proportion of AlN (SiC) in the ceramic material constituting the AlN ceramic member 110 (SiC composite material 120) is 50 wt % or more.

[0058] Conventionally, it has been difficult to join ceramic members whose main component is AlN and ceramic members whose main component is SiC because the CTE values ​​are significantly different (that is, the CTE difference is large).

[0059] In contrast, in the above embodiment and Examples 1 to 7, when the SiC composite 120 is produced, the metal boride is added to the SiC raw powder at an addition rate of 30 wt% to 49 wt%, so that the average thermal expansion coefficient difference between the average thermal expansion coefficient of the AlN ceramic member 110 at 800°C and the average thermal expansion coefficient of the SiC composite 120 at 800°C can be reduced to 0.2 ppm / K or less. As a result, it was found that the occurrence of cracks after bonding the AlN ceramic member 110 and the SiC composite 120 can be suppressed. It was also found that the warping of the upper surface 111 of the AlN ceramic member 110 can be suppressed. It was also found that the thermal conductivity can be increased to 90 W / mK or more. It was found that the relative density of the SiC composite 120 can be increased to 95% or more, and a dense SiC composite 120 can be formed.

[0060] In the above embodiment and Examples 1 to 7, the upper plate 122 of the SiC composite material 120 contains 30 wt % to 49 wt % of metal boride. The lower plate 126 of the SiC composite material 120 contains metal boride. The difference in average linear expansion coefficient between the upper plate 122 at 800° C. and the lower plate 126 at 800° C. is 0.5 ppm / K or less. In addition, when the lower plate 126 is produced, a groove 124 is formed in an upper surface 126a of the lower plate 126.

[0061] By joining the lower plate 126, in which the groove 124 is formed on the upper surface 126a, to the upper plate 122, it is possible to form the SiC composite material 120 having the flow path F formed therein. This allows a coolant such as cooling water to flow through the flow path F, so that the SiC composite material 120 can be easily water-cooled.

[0062] In the first to seventh embodiments, a bonding layer can be disposed between the AlN ceramic member 110 and the SiC composite 120. Also, a bonding layer can be disposed between the AlN ceramic member 110 and the upper plate 122 of the SiC composite 120, or between the upper plate 122 and the lower plate 126 of the SiC composite 120. An Al foil can be used as the bonding layer. By using a bonding layer, bonding can be performed at a lower temperature than in the case of direct bonding (diffusion bonding) without using a bonding layer. This can suppress the stress remaining after bonding, and suppress the warping of the ceramic susceptor 100 after bonding. In addition, by using an Al foil as the bonding layer, a stress buffering effect due to the plastic deformation of Al on the bonding surface can be expected. This can further suppress the stress remaining after bonding, and suppress the warping of the ceramic susceptor 100 after bonding.

[0063] In Examples 1 to 3, the difference in average thermal expansion coefficient between the average thermal expansion coefficient of the AlN ceramic member 110 at 800° C. and the average thermal expansion coefficient of the SiC composite material 120 at 800° C. could be reduced to 0.1 ppm / K or less. Also, in Examples 1, 4, and 6, the difference in average thermal expansion coefficient between the average thermal expansion coefficient of the upper plate 122 at 800° C. and the average thermal expansion coefficient of the lower plate 126 at 800° C. could be reduced to 0.1 ppm / K or less. This further reduced the stress remaining between the AlN ceramic member 110 and the SiC composite material 120 and / or between the upper plate 122 and the lower plate 126, and suppressed warping of the ceramic susceptor 100 after bonding.

[0064] In Examples 1, 4, and 6, the upper plate 122 and the lower plate 126 were directly bonded (diffusion bonding) without interposing a bonding layer such as Al foil between them. In addition, although not disclosed in Examples 1 to 7, in this embodiment, the AlN ceramic member 110 and the SiC composite material 120 can also be directly bonded (diffusion bonding) without interposing a bonding layer such as Al foil between them. In these cases, the produced ceramic susceptor 100 can be used even at a high temperature exceeding the melting point of the bonding layer such as Al foil.

[0065] <Modification form> The above-mentioned embodiment and examples are merely illustrative and may be modified as appropriate. For example, the shapes and dimensions of the AlN ceramic member 110 and the SiC composite material 120 are not limited to those in the above-mentioned embodiment and examples and may be modified as appropriate.

[0066] In the above embodiment and examples, the SiC composite 120 is bonded to the AlN ceramic member 110 to form the ceramic susceptor 100, but the present invention is not limited to such an embodiment. The SiC composite 120 can be used as a SiC matrix member 120A without being bonded to the AlN ceramic member 110 (see FIG. 8). In this case, by adding a metal boride to the raw SiC powder at an addition rate of 20 wt % to 49 wt %, a dense SiC matrix member 120A can be formed, as in the SiC composites 120 of Examples 1 to 7. At this time, the TiB contained in the SiC matrix member 120A 2 is evenly distributed in the SiC structure, and TiB 2 The ratio of the particle size to the SiC particle size is 0.3 to 1.0 (0.3≦TiB 2 Particle size / SiC particle size≦1.0) TiB 2 The fact that the difference between the particle size and the SiC particle size is relatively close is believed to facilitate adjustment of the CTE and to be a factor in making the SiC substrate member 120A structurally stable, which is believed to be a favorable embodiment of the SiC substrate member 120A.

[0067] In the above embodiment and examples, the SiC composite 120 is bonded to the AlN ceramic member 110 to form the ceramic susceptor 100, but the present invention is not limited to such an embodiment. Any member having an average linear expansion coefficient that differs from the average linear expansion coefficient of the SiC composite 120 at 800°C by 0.2 ppm / K or less can be used in place of the AlN ceramic member 110. Also, a ceramic susceptor can be formed by bonding another ceramic member to the above-mentioned SiC substrate member 120A.

[0068] As described above, the lower plate 126 having the groove 124 formed in the upper surface 126a and the lower surface 122b of the upper plate 122 are joined together to form the SiC substrate member 120A having the flow path F formed therein. The groove 124 can also be formed in the lower surface 122b of the upper plate 122. Alternatively, the groove 124 can be formed in both the lower surface 122b of the upper plate 122 and the upper surface 126a of the lower plate 126. This allows a coolant such as cooling water to flow through the flow path F, so that the SiC substrate member 120A can be easily water-cooled. The upper surface 122a of the upper plate 122 becomes the main surface of the SiC substrate member 120A.

[0069] Although the present invention has been described above using the embodiment and its modified form, the technical scope of the present invention is not limited to the above description. It is obvious to those skilled in the art that various modifications or improvements can be made to the above embodiment. It is also clear from the claims that such modifications or improvements can be included in the technical scope of the present invention.

[0070] The order of execution of each process in the manufacturing method shown in the specification and drawings is not particularly specified, and may be any order unless the output of a previous process is used in a subsequent process. For convenience, even if the description uses "first," "next," etc., it does not mean that the process must be performed in that order. [Explanation of symbols]

[0071] 100 Ceramic susceptor 110 AlN ceramics components 120 SiC composite 120A SiC substrate material 140 electrodes

Claims

1. an AlN ceramic member having an upper surface and a lower surface facing the upper surface in the vertical direction, the AlN ceramic member being mainly composed of AlN; and a plate-shaped SiC composite material having a main surface joined to the upper surface or the lower surface of the AlN ceramic member, containing SiC as a main component and containing 30 wt % to 49 wt % of a metal boride, and having an average linear expansion coefficient whose difference from the average linear expansion coefficient of the AlN ceramic member at 800°C is 0.2 ppm / K or less.

2. The SiC composite material is An upper plate mainly composed of SiC and containing 35 wt % to 49 wt % of the metal boride; a lower plate having an upper surface bonded to a lower surface of the upper plate, the lower plate being composed mainly of SiC, containing the metal boride, and having an average linear expansion coefficient whose difference from the average linear expansion coefficient of the upper plate at 800° C. is 0.5 ppm / K or less; 2. The ceramic susceptor according to claim 1, wherein a groove is formed in at least one of the lower surface of the upper plate and the upper surface of the lower plate.

3. The ceramic susceptor according to claim 1 , further comprising a bonding layer disposed between the AlN ceramic member and the SiC composite material.

4. The ceramic susceptor according to claim 2 , further comprising a bonding layer disposed between the AlN ceramic member and the upper plate of the SiC composite, or between the upper plate and the lower plate of the SiC composite.

5. 5. The ceramic susceptor according to claim 3, wherein the bonding layer contains Al.

6. 2. The ceramic susceptor according to claim 1, wherein a difference in average linear expansion coefficient between said AlN ceramic member and said SiC composite material at 800° C. is 0.1 ppm / K or less.

7. A ceramic susceptor as described in claim 2, wherein the difference in average linear expansion coefficient between the average linear expansion coefficient of the AlN ceramic member and the average linear expansion coefficient of the upper surface of the SiC composite material, or the difference in average linear expansion coefficient between the average linear expansion coefficient of the upper plate and the average linear expansion coefficient of the lower plate at 800°C, is 0.1 ppm / K or less.

8. 7. The ceramic susceptor according to claim 6, wherein the AlN ceramic member and the SiC composite material are directly bonded to each other.

9. 8. The ceramic susceptor according to claim 7, wherein the upper plate and the lower plate of the SiC composite are directly bonded to each other.

10. Contains SiC as a main component and TiB ２ The TiB ratio is 20 wt% to 49 wt% relative to the average grain size R1 of SiC. ２ The ratio (R2 / R1) of the average particle diameter R1 to the average particle diameter R2 of the plate-shaped SiC substrate member is 0.3 or more and 1.0 or less, and the plate-shaped SiC substrate member has a flow path formed therein.

11. Contains SiC as a main component and TiB ２ The average particle size R1 of SiC is 35 wt% to 49 wt%. ２ an upper plate having an average particle size R2 of 0.3 or more and 1.0 or less (R2 / R1); Contains SiC as a main component and TiB ２ The TiB content is 20 wt% to 35 wt%, and the average particle size R1 of SiC is ２ a ratio (R2 / R1) of the average particle diameter R2 of the upper plate to the average particle diameter R3 of the lower plate is 0.3 or more and 1.0 or less, and a lower plate having an upper surface joined to the lower surface of the upper plate, A SiC substrate member having grooves formed in at least one of the lower surface of the upper plate and the upper surface of the lower plate.

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