JP2000327424A - Aluminum nitride base sintered compact, its production and susceptor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sintered compact, containing silicon carbide of a specific ratio and the balance aluminum nitride and inevitable impurities, excellent in plasma resistance after used for a long period of time and high in radiation absorptivity and coefficient of thermal conductivity by limiting the average crystal particle size and CIE 1976 lightness L* of the sintered compact to specific values or low. SOLUTION: This aluminum nitride(AlN) base sintered compact contains 0.1-20 wt.% silicon carbide and the balance aluminum nitride and inevitable impurities and has <=20 μm average crystal particle size and <=30 CIE 1976 lightness L*. It is preferably obtained by sintering AlN powder containing 0.1-20 wt.% SiC powder synthesized in gas phase by a plasma CVD method to have 10-100 nm average particle size under >=10 MPa at 1,700-2,300 deg.C. One or more of yttria, calcia and magnecia can be added as a sintering aid by 1.0-10.0 wt.% in total to improve the sinterability. This sintered compact is suitable for a susceptor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum nitride-based sintered body, a method for producing the same, and a susceptor using the same, and more particularly, to a plasma-resistant, high radiation-absorbing and thermal-conducting material. The present invention relates to an aluminum nitride-based sintered body that does not have a risk of deteriorating the characteristics of a thin film on an object to be processed, a method of manufacturing the same, and a susceptor using the same.

[0002]

2. Description of the Related Art Conventionally, in a production line for semiconductor devices such as ICs, LSIs, and VLSIs, for example, a silicon oxide film (SiO ₂ ) or a silicon nitride film (Si ₃ N ₄ ) is formed on a surface of a substrate such as a silicon wafer. In order to form an insulating film such as an insulating film or a conductor film such as a silicide film (WSi ₂ ), a thermal CVD method,
A plasma CVD method or the like is preferably used. In these CVD methods, a silicon wafer as an object to be processed is placed on a sample table (pedestal) called a susceptor and subjected to a predetermined process.

The susceptor is required to have excellent plasma resistance and high thermal conductivity because it needs to withstand use in plasma and keep the whole heat uniform. One type of susceptor having such characteristics is one using an aluminum nitride sintered body.

However, in a susceptor using this aluminum nitride sintered body, the amount of radiant heat absorbed is small because the color tone of the aluminum nitride sintered body itself, which is a material, is white, and therefore, the heat conversion efficiency of radiant energy is high. Was insufficient. For example, when the susceptor is irradiated with infrared rays from an external resistance heating element, an infrared lamp, or the like, the heat conversion efficiency is reduced due to a low absorption rate of the infrared rays.

[0005] The aluminum nitride sintered body itself has a complicated microstructure in which particles, grain boundaries, pores, and the like are connected three-dimensionally, and is accompanied by grain growth during the firing process. However, it is inevitable that a certain degree of spread occurs in the distribution of the crystal grain size. Therefore, color unevenness due to relatively large crystal grains occurs on the surface of the aluminum nitride sintered body, and as a result, the radiation absorptivity varies, and the heat uniformity decreases.

Furthermore, since the plasma resistance is not sufficient, coarse particles are generated and scattered from the susceptor by plasma irradiation, and there is a problem that an object to be processed on the susceptor has a problem. For example, in a semiconductor manufacturing line, when plasma is irradiated, particles are generated from an aluminum nitride sintered body, and the particles are deposited on a silicon wafer or a thin film to be formed, thereby breaking a metal wiring, There has been a problem that a problem such as deterioration of the characteristics of the semiconductor layer occurs.

Therefore, this aluminum nitride sintered body is
For example, a metal element such as tungsten (W), nickel (Ni), palladium (Pd) is added, or
Attempts have been made to blacken the aluminum nitride sintered body by forming a second layer such as an AlON phase or a C phase on the surface of the aluminum nitride sintered body. In addition, in order to improve the plasma resistance of the aluminum nitride sintered body, an aluminum nitride thin film having a high-purity and uniform structure by a gas-phase synthesis method and an excellent plasma-resistant A susceptor having a thin film formed of a metal fluoride, yttrium aluminum garnet (YAG), or the like has been proposed.

[0008]

In a susceptor obtained by adding a metal element to a sintered body, the radiant absorptivity of the aluminum nitride sintered body is improved, but the metal impurity concentration in the sintered body is affected by the additive. Therefore, when plasma is irradiated, there is a problem that the metal impurities obtain energy and are scattered to contaminate an object to be processed and a thin film.
In particular, when this susceptor is used in a semiconductor device manufacturing line, the silicon wafer and the semiconductor layer are contaminated by metal impurities in the sintered body, and the characteristics of the obtained semiconductor device are greatly deteriorated.

In the susceptor having the second layer formed on the surface, the thermal conductivity of the susceptor is reduced due to the low thermal conductivity of the second layer. There was a problem of doing. Furthermore, these susceptors have not yet been improved in improving color unevenness due to crystal grain size.

On the other hand, in the case of a susceptor having a thin film formed on the surface for the purpose of improving plasma resistance, only the thin film portion on the surface shows corrosion resistance against plasma, and therefore, a short-term improvement in plasma resistance is recognized. However, when used for a long time, the thin film on the surface disappears due to plasma irradiation, and it is difficult to maintain the initial plasma resistance for a long time. Further, when the composition, crystal structure, coefficient of thermal expansion, and the like are different between the thin film and the aluminum nitride sintered body, there is a possibility that peeling, tearing, and the like may occur in the thin film by repeating a cycle of increasing and decreasing the temperature. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has excellent plasma resistance during long-term use, high radiation absorption and thermal conductivity, and also has a large An object of the present invention is to provide an aluminum nitride-based sintered body having no risk of deteriorating the properties of a thin film, a method for producing the same, and a susceptor using the same.

[0012]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have obtained the following knowledge. A predetermined amount of the silicon carbide powder synthesized in the gas phase is added to the aluminum nitride powder, and the mixed powder is subjected to pressure sintering under conditions such that the crystal grain size is equal to or smaller than a predetermined value, thereby adding a metal element. Alternatively, the sintered body could be blackened without forming a second phase or the like, and there was no color unevenness due to crystal grain boundaries, and a material excellent in corrosion resistance to plasma was obtained. And it became clear that the problem in the conventional susceptor can be solved by using this material for the susceptor. The present inventors,
The present invention has been completed based on the above findings.

That is, the aluminum nitride-based sintered body according to the first aspect of the present invention comprises silicon carbide in an amount of 0.1 to 20% by weight.
Containing, with the balance being aluminum nitride and inevitable impurities, having an average crystal grain size of 20 μm or less,
Further, the CIE 1976 lightness L ^* is 30 or less.

According to a second aspect of the present invention, there is provided an aluminum nitride-based sintered body selected from the group consisting of the yttria (Y ₂ O ₃ ), calcia (CaO), and magnesia (MgO). It is characterized in that one or more kinds are contained in a total of 1.0 to 10.0% by weight.

According to a third aspect of the present invention, there is provided a method for producing an aluminum nitride-based sintered body, comprising: applying an aluminum nitride powder containing 0.1 to 20% by weight of silicon carbide powder having an average particle diameter of 10 to 100 nm under a pressure of 10 MPa or more. , 1700-2300
It is characterized by firing at a temperature of ° C.

According to a fourth aspect of the present invention, in the method for manufacturing an aluminum nitride-based sintered body according to the third aspect, the silicon carbide powder is synthesized in a gas phase by a gas phase reaction method. It is characterized by:

According to a fifth aspect of the present invention, there is provided a method of manufacturing an aluminum nitride-based sintered body according to the fourth aspect of the present invention, wherein the gas phase reaction method comprises a plasma CVD method.
It is characterized by the VD method.

A susceptor according to a sixth aspect is characterized in that the substrate is made of the aluminum nitride-based sintered body according to the first or second aspect.

In the aluminum nitride-based sintered body of the present invention,
By setting the average crystal grain size of a sintered body having a composition containing 0.1 to 20% by weight of silicon carbide and the remainder being aluminum nitride and unavoidable impurities to 20 μm or less, distribution of the crystal grain size in the sintered body Becomes sharp and uniform.
Thereby, color unevenness due to the crystal grain size is eliminated, and as a result, the variation in the radiation absorptivity becomes extremely small, and the heat uniformity is improved. Also, the CIE 1976 lightness L ^{* is set} to 3
By setting the value to 0 or less, the sintered body is blackened, and the radiation absorptivity is increased. Moreover, since there is no second component such as the AlON phase and the C phase as in the conventional case, there is no possibility that the thermal conductivity is reduced, and the uniformity is not reduced.

In the method for producing an aluminum nitride-based sintered body according to the present invention, an aluminum nitride powder containing 0.1 to 20% by weight of silicon carbide powder having an average particle diameter of 10 to 100 nm is subjected to a pressure of 1 MPa or more under 1700 MPa. By firing at a temperature of 2300 ° C., a black sintered body is obtained, which has a high radiation absorptance, has excellent color uniformity due to crystal grain size, has excellent heat uniformity, and has no pores. .

[0021] In the susceptor of the present invention, the substrate is made of the following.
Or, by using the aluminum nitride-based sintered body described in 2, the sintered body does not disappear even when plasma irradiation is performed for a long time, and the initial plasma resistance is maintained for a long time. Becomes possible. Further, since the base is made of a single aluminum nitride-based sintered body, even if the cycle of temperature rise and fall is repeated, there is no possibility that the sintered body will be peeled, broken, etc. As the reliability increases.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the aluminum nitride-based sintered body of the present invention, a method for producing the same, and a susceptor using the same will be described. However, this embodiment does not limit the contents of the invention unless otherwise specified.

The aluminum nitride (AlN) -based sintered body of the present invention has a composition containing 0.1 to 20% by weight of silicon carbide (SiC), with the balance being aluminum nitride (AlN) and unavoidable impurities. Average crystal grain size of 20 μm or less,
Further, blackening is achieved by setting the CIE 1976 lightness L ^* to 30 or less.

SiC is an important compound for adjusting the brightness of the AlN-based sintered body and improving the plasma resistance, and its content is in the range of 0.1 to 20% by weight. The reason is that if the content is less than 0.1% by weight, sufficient brightness is not obtained due to whitening and no improvement in plasma resistance is observed, and the content is 20% by weight.
This is because, if it exceeds, it becomes difficult to obtain a dense sintered body, and the plasma resistance is greatly reduced.

The SiC is α-SiC, β-SiC,
a-SiC (amorphous SiC) or a mixed phase thereof may be used. Among them, β-SiC has a small aspect ratio and is excellent in dispersibility. The color tone of the AlN-based sintered body
IE 1976 Blackness with a lightness L ^* of 30 or less can be obtained, and plasma resistance can be improved.

The average crystal grain size of the AlN-based sintered body needs to be 20 μm or less. The reason is,
If the average crystal grain size exceeds 20 μm, color unevenness which can be visually confirmed is generated, which causes non-uniformity of thermal efficiency and greatly reduces plasma resistance. When an AlN-based sintered body having an average crystal grain size exceeding 20 μm is applied to a susceptor, the particle size of particles generated by plasma irradiation increases, and there is a possibility that a defect such as disconnection of wiring may occur in the obtained semiconductor. .

The CIE 19 of this AlN-based sintered body was
The 76 lightness L ^* needs to be 30 or less. This lightness L ^*
Represents the degree of radiation absorption on the surface of the AlN-based sintered body. When the value is 30 or less, excellent performance of absorbing external radiant energy as heat is obtained.

This CIE 1976 lightness L^*Is Nippon Kogyo
Industry Standards Specified in JIS Z8729 “Color Display Method”
And recommended by the International Commission on Lighting (CIE)
CIE1976 (L^*a^*b^*Color space) (CIE LAB
Abbreviation) is the value defined as lightness,
The launch surface is 100, the perfect black body is 0, and the degree between them is
Expressed by an expression related to the value of Y in the tristimulus values of color
It is. This lightness L ^*Means that the smaller the value, the more radiation
It is close to a perfect black body that absorbs 100%, and has an external heating element and run
Absorbs energy radiated from pumps as heat
Excellent ability.

This AlN-based sintered body has an average particle diameter of 10
AlN powder containing 0.1 to 20% by weight of SiC powder having a thickness of 100
It can be obtained by firing at a temperature of 2300 ° C. As the SiC powder, for example, a fine powder having an average particle diameter of 10 to 100 nm synthesized by a gas phase using a plasma CVD method is used. Due to this, corrosion resistance to plasma,
In particular, it has excellent corrosion resistance to fluorine-based plasma. As the plasma CVD method, a method using high-frequency plasma (RF plasma) capable of achieving high purity is preferable. Since this high-frequency plasma has no electrodes, it is possible to obtain, for example, ultra-high-purity SiC fine powder having an impurity concentration of 1 ppm or less.

S synthesized in a gas phase by a plasma CVD method
The iC powder is not particularly limited in terms of the vapor phase synthesis conditions and its crystal phase, but from the viewpoint of improving the sinterability of the AlN-based sintered body and improving its thermal and mechanical properties, in particular, β- S
Preferred are iC fine powder, amorphous SiC fine powder, or SiC fine powder composed of a mixed phase thereof. Above all, β-S
Since the iC fine powder has a small aspect ratio and excellent dispersibility, the color tone of the obtained AlN-based sintered body can be blackened by simply mixing a small amount with the AlN powder, and the plasma resistance is also improved. Can be done.

The SiC fine powder is prepared by introducing a raw material gas composed of a mixed gas of a silane compound or a silicon halide and a hydrocarbon into plasma in a non-oxidizing atmosphere, and reducing the pressure of the reaction system from less than 1 atm to 0.1. It can be obtained by performing a gas phase reaction while controlling within a range of 1 Torr.

The average particle size of the SiC powder is 10 to 10
0 nm (0.1 μm). A more preferred value of the upper limit of the average particle size is 30 nm or less. S of this average particle diameter
By using iC powder, SiC easily dissolves into AlN during firing, and an AlN-based sintered body having a uniform composition can be obtained. This AlN-based sintered body is excellent in plasma resistance because there is no segregation of substances having different compositions in the grain boundary layer, for example, unreacted SiC or the like. In addition, this AlN
When the base sintered body is applied to the susceptor, there is no possibility that particles are generated during plasma irradiation. The reason for setting the average particle diameter to 10 nm or more is that if the average particle diameter is less than 10 nm, it is too fine to handle, and the cost is disadvantageous.

The content of the SiC powder is 0.1 to 20% by weight based on the mixed powder including the SiC powder and the AlN powder.
It is necessary to be. The reason is that the content is 0.1
If the content is less than 20% by weight, sufficient brightness cannot be obtained, and no improvement in plasma resistance is observed. If the content exceeds 20% by weight, grain growth proceeds too much during firing, resulting in a dense sintered body. This is because it becomes difficult to obtain, and the plasma resistance is greatly reduced.

The AlN powder is not particularly limited, but for example, a commercially available powder obtained by an alumina reduction method, a direct nitriding method of aluminum, or the like can be used. Further, the average particle size of the AlN powder may be any range as long as the average crystal grain size after firing does not exceed 20 μm, and is, for example, in the range of 0.1 to 10 nm. In order to improve the sinterability of the AlN-based sintered body, yttria (Y ₂ O ₃ ),
One or more selected from calcia (CaO) and magnesia (MgO) may be added in a total amount of 1.0 to 10.0% by weight.

The mixed powder containing the SiC powder and the AlN powder may be formed into a green compact having a predetermined shape by pressure molding with a powder molding machine or the like, or a pressure sintering machine such as a hot press (HP). May be filled in a pressurized container. The method of press molding is not particularly limited, and a known molding method may be used. Further, at the time of molding, an organic compound such as polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP) or ethyl cellulose may be used as a binder, and if necessary, a dispersant such as stearic acid or a stearic acid salt may be added. May be.

As the pressure sintering method, hot press (HP), high-temperature isotropic pressure sintering (HIP), etc., which can obtain a high-density and high-strength sintered body in a short time, are preferably used. The pressure during pressure sintering needs to be 10 MPa or more. Al
The N-based sintered body is made of AlN
However, as the uniaxial pressure during pressure sintering increases, the diffusion amount of SiC increases, and the color tone of the sintered body also changes from white to gray-white and further to black.
In particular, by sintering under a uniaxial pressure of 10 MPa or more, all the brightness L ^* of the obtained AlN-based sintered body becomes 30 or less. Therefore, the AlN-based sintered body has a large absorption amount of radiant energy, and has an excellent efficiency of absorbing externally radiated energy as heat.

The firing temperature during pressure sintering is 1700-2.
The temperature must be in the range of 300 ° C. The reason is that if the firing temperature is lower than 1700 ° C., the diffusion of SiC into the AlN crystal lattice is insufficient, the color tone of the obtained AlN-based sintered body does not turn black, and the density of the sintered body is high. On the other hand, if the temperature exceeds 2300 ° C., A
This is because the decomposition reaction of 1N proceeds, the number of pores in the sintered body increases, the density of the sintered body is significantly reduced, and a dense AlN-based sintered body cannot be obtained. The atmosphere during the pressure sintering is not particularly limited, and any of a vacuum atmosphere, an inert atmosphere such as N ₂ gas, and a reducing atmosphere such as CO gas can be used.

In such an AlN-based sintered body, the average crystal grain size of a sintered body containing 0.1 to 20% by weight of silicon carbide and the balance of aluminum nitride and unavoidable impurities is 20 μm. Since the CIE 1976 lightness L ^{* is set} to 30 or less, there is no color unevenness due to the crystal grain size, the variation in the radiation absorptivity is extremely small, and the heat uniformity is improved. Further, since the color tone is black, the efficiency of absorbing energy applied as radiation from the outside as heat is increased.

In such a method for producing an AlN-based sintered body, an aluminum nitride powder containing 0.1 to 20% by weight of a silicon carbide powder having an average particle diameter of 10 to 100 nm is placed under a pressure of 10 MPa or more. Since it is fired at a temperature of 1700 to 2300 ° C., a dense sintered body having a high radiation absorption rate, excellent color uniformity due to crystal grain size, excellent heat uniformity, and no pores can be obtained.

By forming a susceptor base using such an AlN-based sintered body, the color tone is black, there is no color unevenness, and a high thermal conductivity and high radiation absorption are provided. In addition, since the susceptor is excellent in corrosion resistance to plasma, particularly to fluorine plasma, plasma cleaning can be performed when this susceptor is used in a thermal CVD apparatus. Can be.

Hereinafter, Examples and Comparative Examples of the present invention will be described. (Example 1) "Preparation of AlN-based sintered body" A? -SiC fine powder having an average particle diameter of 30 nm was synthesized in a gas phase by a plasma CVD method.
Here, SiH ₄ and C ₂ H ₄ are used as source gases,
With the pressure of the reaction system controlled at 0.08 Torr, argon thermal plasma was excited by high frequency, and gas phase synthesis was performed in the argon thermal plasma.

Next, this β-SiC fine powder and a commercially available AlN powder (manufactured by Tokuyama Corporation, average particle size: 0.6 μm)
Was mixed in the ratio shown in Table 1, and this mixed powder was charged into a ball mill together with isopropyl alcohol (solvent), and the ball mill was run for a predetermined time to obtain a slurry. Next, this slurry was spray-dried using a spray dryer or the like to obtain granulated powder. Next, the granulated powder is filled in a graphite hot press container, and baked under a uniaxial pressure of 20 MPa, 1 atmosphere and 1800 ° C. in a nitrogen atmosphere for 2 hours to obtain a disc-shaped AlN-based sintered body. Was.

Next, the average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and the plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results. "Average crystal grain size" The average crystal grain size of the AlN-based sintered body was observed by a scanning electron microscope (SEM) and measured by an intersect method.

[Sputter Mark Size and Plasma Resistance] The sputter mark size on the surface of the AlN-based sintered body after plasma irradiation was measured by the following method. The obtained AlN-based sintered body was placed in an ECR etching apparatus, and a CF ₄ plasma generated by applying a voltage of 500 V and a current of 0.16 A in CF ₄ gas to the AlN-based sintered body for 1000 minutes. Irradiation resulted in plasma exposure.

The sputter marks on the surface of the AlN-based sintered body, which were marks removed by the plasma irradiation, were observed with a scanning electron microscope (SEM), and the average of the top 10 sputter marks existing in 1 mm ² was measured. The value was taken as the sputter mark size. In addition, the size of the sputter mark obtained by the measurement was estimated to be equivalent to the size of the scattered particles, and the plasma resistance was evaluated.

"Lightness L ^* and color tone (degree of blackening)" Color analyzer (TC-180 manufactured by Tokyo Denshoku Center)
0MKII), the JIS of the surface of the AlN-based sintered body
The lightness L ^* specified in Z8729 was measured, and the color tone (degree of blackening) of the AlN-based sintered body was evaluated.

(Examples 2-5) β-SiC fine powder and Al
An AlN-based sintered body was obtained in the same manner as in Example 1, except that the mixing ratio of the N powder was changed to the ratio shown in Table 1. Next, the average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results.

(Examples 6 and 7) The same procedure as in Example 1 was carried out except that the uniaxial pressing force was changed to the pressure shown in Table 1.
An N-based sintered body was obtained. Next, the average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results.

Comparative Example 1 AlN used in Examples 1 to 7
An AlN-based sintered body was obtained in the same manner as in Example 1, except that only the powder was used as the raw material powder. Next, the average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results.

Comparative Example 2 An AlN-based sintered body was obtained in the same manner as in Example 1, except that the mixing ratio between the β-SiC fine powder and the AlN powder was changed to the ratio shown in Table 1. Then
The average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results.

Comparative Example 3 A mixed powder obtained by mixing a commercially available SiC powder (manufactured by Ibiden Co., Ltd., average crystal grain size: 0.3 μm) and the AlN powder used in Examples 1 to 7 at a ratio shown in Table 1 was used. Except for the point of use, the same procedure as in Example 1 was performed to obtain an AlN-based sintered body. Next, the average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results.

Comparative Example 4 An AlN-based sintered body was obtained in the same manner as in Example 1 except that the uniaxial pressing force was changed to the pressure (3 MPa) shown in Table 1. Next, the average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results.

Comparative Example 5 An AlN-based sintered body was obtained in the same manner as in Example 1, except that the uniaxial pressing force was changed to the pressure (4 MPa) shown in Table 1. Next, the average crystal grain size, sputter mark size, and lightness L ^* of the AlN-based sintered body were measured, and plasma resistance and color tone (degree of blackening) were evaluated. Table 1 shows the results.

[0054]

[Table 1]

The AlN-based sintered bodies of Examples 1 to 7 are all black, but the AlN-based sintered bodies of Comparative Examples 1 and 4 are white, that of Comparative Example 3 is gray-green, and that of Comparative Example 5 is gray-white. there were. Therefore, the AlN-based sintered bodies of Examples 1 to 7 were excellent in thermal conductivity and highly efficient in absorbing radiation as heat.

In Examples 1 to 7 and Comparative Examples 1 to 3, A
When the 1N-based sintered body was used as a base of the susceptor and the size of particles generated when the susceptor was irradiated with CF ₄ plasma was compared, the susceptors using the AlN-based sintered bodies of Examples 1 to 7 were compared. It was smaller than those of Examples 1 to 3 and was found to be excellent in plasma resistance.

Further, Examples 1, 6, 7 and Comparative Examples 4, 5
From the relationship between the uniaxial pressing force and the color tone of the AlN-based sintered body of
When the uniaxial pressure during sintering is 10 MPa or more, a black AlN-based sintered body is obtained, but the uniaxial pressure is 10 MPa.
It was found that below a, only a white or gray-white AlN-based sintered body could be obtained.

[0058]

As described above, according to the aluminum nitride-based sintered body of the present invention, the sintered body has a composition containing 0.1 to 20% by weight of silicon carbide, with the balance being aluminum nitride and unavoidable impurities. Since the average crystal grain size of the body is set to 20 μm or less, the crystal grain size in the sintered body can be made uniform, thereby eliminating color unevenness due to the crystal grain size, and making the variation in radiation absorptivity extremely small. And the heat uniformity can be improved.

Further, since the CIE 1976 lightness L ^{* is set} to 30 or less, the color tone becomes black, and the efficiency of absorbing externally applied energy as heat can be increased. Furthermore, there is no second component such as the AlON phase and the C phase as in the conventional case, and there is no fear that the thermal conductivity is reduced or the uniformity is reduced.

According to the method for producing an aluminum nitride-based sintered body of the present invention, aluminum nitride powder containing 0.1 to 20% by weight of silicon carbide powder having an average particle size of 10 to 100 nm is subjected to a pressure of 10 MPa or more. , 1700-2300
Since it is fired at a temperature of ° C., it is possible to obtain a dense sintered body having high radiation absorptivity, excellent color uniformity due to crystal grain size, excellent thermal uniformity, and no pores. In addition, since an ordinary pressure sintering method can be applied, an expensive and complicated manufacturing apparatus is not required, and an aluminum nitride-based sintered body having excellent characteristics can be easily manufactured.

According to the susceptor of the present invention, since the substrate is made of the aluminum nitride-based sintered body according to claim 1 or 2, it has excellent corrosion resistance to plasma, and coarse particles even when exposed to plasma. There is no danger of occurrence, and the initial plasma resistance can be maintained for a long time even when plasma irradiation is performed for a long time.

Moreover, since it does not contain any impurity element such as a metal element for making the color tone black, there is no risk of contaminating the semiconductor, and a susceptor suitable for a thermal CVD apparatus or a plasma CVD apparatus can be obtained. Further, since the base is made of a single aluminum nitride-based sintered body, even if the cycle of temperature rise and fall is repeated, there is no possibility that the sintered body will be peeled, broken, etc. Reliability can be increased.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C04B 35/64 302Z (72) Inventor Hiroshi Lightning 585 Tomicho, Funabashi-shi, Chiba Sumitomo Osaka Cement Co., Ltd. New Technology Research Laboratory (72) Inventor Yoshiki Yoshioka 585 Tomicho, Funabashi City, Chiba Prefecture Sumitomo Osaka Cement Co., Ltd.New Technology Research Laboratory (72) Inventor Masayuki Ishizuka 585 Tomimachi, Funabashi City, Chiba Prefecture Sumitomo Osaka Cement Co., Ltd. 4G001 BA06 BA07 BA09 BA22 BA36 BB06 BB07 BB09 BB22 BB36 BC01 BC42 BD03 BD38 5F045 AA08 BB14 BB15 EM01 EM09

Claims (6)

[Claims] Claims: 1. A silicon carbide content of 0.1 to 20% by weight,
The balance consists of aluminum nitride and unavoidable impurities, the average crystal grain size is 20 μm or less, and CIE 1
An aluminum nitride-based sintered body, wherein 976 lightness L ^* is 30 or less. 2. One or more selected from yttria, calcia, and magnesia in total of 1.0 to 10.
The aluminum nitride-based sintered body according to claim 1, which contains 0% by weight. 3. An aluminum nitride powder containing 0.1 to 20% by weight of a silicon carbide powder having an average particle diameter of 10 to 100 nm is subjected to a pressure of 1 MPa or more under a pressure of 1700 to 2300.
A method for producing an aluminum nitride-based sintered body, characterized by firing at a temperature of ° C. 4. The method for producing an aluminum nitride-based sintered body according to claim 3, wherein said silicon carbide powder is synthesized by a gas phase reaction method. 5. The method according to claim 4, wherein the gas phase reaction method is a plasma CVD method. 6. A susceptor, wherein the base is made of the aluminum nitride-based sintered body according to claim 1.