JP4429742B2 - Sintered body and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sintered body and a method for manufacturing the same, and more specifically, for example, is suitably used for a structural member in a semiconductor manufacturing apparatus such as a dry etching apparatus or a cleaning apparatus, an etching electrode, and a dielectric material for an electrostatic chuck. Further, the present invention relates to a sintered body having high corrosion resistance against halogen-based corrosive gases such as fluorine-based corrosive gas and chlorine-based corrosive gas, and plasmas thereof, and excellent conductivity, and a method for producing the same.

Conventionally, in the production line of semiconductor devices such as IC, LSI, VLSI, etc., there are processes using halogen-based corrosive gas such as fluorine-based corrosive gas, chlorine-based corrosive gas and their plasma, especially dry etching process. In the cleaning process, corrosion of the components in the semiconductor manufacturing apparatus due to the corrosive gas and plasma is a problem. Therefore, an aluminum oxide sintered body, an yttrium oxide sintered body, etc. are used as a corrosion-resistant member (for example, refer patent documents 1 and 2).
Further, in the process using the halogen-based corrosive gas and the plasma described above, there are members that require corrosion resistance and conductivity, such as an etching electrode, for example, but at present, both the conductivity and the corrosion resistance are provided. Since there is no suitable material, silicon or a silicon-based compound having insufficient corrosion resistance is used as a material for constituting the etching electrode or the like (see, for example, Patent Documents 3 and 4).
Japanese Patent Laid-Open No. 11-246263 JP 2002-255647 A JP 2002-231698 A JP 2002-353294 A

By the way, although the conventional aluminum oxide sintered body and yttrium oxide sintered body have excellent corrosion resistance, since the sintered body itself is insulative, it cannot be used for a member requiring electrical conductivity. There was a point.
Further, since conventional silicon or silicon-based compounds have insufficient corrosion resistance against halogen-based corrosive gases and their plasmas, when used as a corrosion-resistant member, consumption is severe, and parts associated with these consumption There was a problem that the exchange had a great influence on the throughput reduction of the semiconductor manufacturing.
Thus, there is a strong demand for the emergence of halogen-based corrosive gases and materials that have both corrosion resistance and conductivity against these plasmas, but such materials have not yet been proposed.

  The present invention has been made to solve the above-described problems, and aims to provide a sintered body having both corrosion resistance and conductivity against halogen-based corrosive gases and their plasmas, and a method for producing the same. To do.

  The present inventor pays attention to the yttrium oxide-based sintered body, which is one of the most excellent corrosion resistance materials in the existing ceramics, and reduces the corrosion resistance of the yttrium oxide-based sintered body to the halogen-based corrosive gas and these plasmas. As a result of intensive studies to provide excellent conductivity, the present invention has been completed.

That is, the sintered body of the present invention is characterized by comprising metal yttrium and yttrium oxide, and the content of the metal yttrium is 0.5 vol% or more and 10 vol% or less .

Another sintered body of the present invention comprises at least one selected from the group of carbon, yttrium nitride, and yttrium carbide, and yttrium oxide, and at least one of aluminum oxide, zirconium oxide, and silicon oxide. At least one selected from the group consisting of yttrium nitride and yttrium carbide is 5% by volume to 30% by volume, and the yttrium oxide is 60% by volume to 95% by volume.

In the sintered body of the present invention, the metal yttrium is preferably segregated at grain boundaries.

The method for producing a sintered body of the present invention comprises forming a mixed powder comprising a metal yttrium powder and an yttrium oxide powder, wherein the content of the metal yttrium powder is 0.5 volume% or more and 10 volume% or less. A molded body is formed, and the molded body is fired.

Another method for producing the sintered body of the present invention is a mixed powder comprising metal yttrium powder and yttrium oxide powder, wherein the content of the metal yttrium powder is 0.5 volume% or more and 10 volume% or less. The mixed powder is heated and pressurized.

Still another method for producing the sintered body of the present invention includes at least one selected from the group consisting of carbon powder, yttrium nitride powder, and yttrium carbide powder, yttrium oxide powder, aluminum oxide powder, zirconium oxide powder, and silicon oxide. And at least one selected from the group consisting of the carbon powder, the yttrium nitride powder, and the yttrium carbide powder, 5 vol% or more and 30 vol% or less, and the yttrium oxide powder is 60 vol% or more. The mixed powder having a volume of 95% by volume or less is molded to form a molded body, and the molded body is fired.

Still another method for producing the sintered body of the present invention includes at least one selected from the group consisting of carbon powder, yttrium nitride powder, and yttrium carbide powder, yttrium oxide powder, aluminum oxide powder, zirconium oxide powder, and silicon oxide. And at least one selected from the group consisting of the carbon powder, the yttrium nitride powder, and the yttrium carbide powder, 5 vol% or more and 30 vol% or less, and the yttrium oxide powder is 60 vol% or more. The mixed powder set to 95% by volume or less is filled in a mold, and the mixed powder is heated and pressurized.

According to the sintered body of the present invention, since it is made of yttrium metal and yttrium oxide, it has excellent conductivity in addition to the corrosion resistance against halogen-based corrosive gases and these plasmas.
Moreover, since the content of metal yttrium is 0.5 volume% or more and 10 volume% or less, the conductivity can be further enhanced without any loss of the corrosion resistance against halogen-based corrosive gases and their plasmas. .

According to another sintered body of the present invention, it comprises at least one selected from the group consisting of carbon, yttrium nitride, and yttrium carbide, and yttrium oxide, and at least one of aluminum oxide, zirconium oxide, and silicon oxide. Since at least one selected from the group consisting of carbon, yttrium nitride, and yttrium carbide is 5 volume% or more and 30 volume% or less, and yttrium oxide is 60 volume% or more and 95 volume% or less. In addition to the corrosion resistance to plasma, it can have excellent conductivity.

  Also, if metal yttrium is segregated at the grain boundaries, a small amount of conductive substance called metal yttrium is segregated at the grain boundaries, so that the corrosion resistance to halogen-based corrosive gases and these plasmas is not impaired. The conductivity can be further increased, and no generation of particles is caused.

According to the method for producing a sintered body of the present invention, a mixed powder comprising metal yttrium powder and yttrium oxide powder and having a metal yttrium powder content of 0.5 volume% or more and 10 volume% or less is formed. Since the molded body is fired, the sintered body having excellent conductivity in addition to the halogen-based corrosive gas and corrosion resistance to these plasmas can be used without any change to the existing ceramic manufacturing equipment. Can be manufactured at low cost.

According to another method for producing a sintered body of the present invention, a mixed powder comprising metal yttrium powder and yttrium oxide powder, wherein the content of the metal yttrium powder is 0.5 volume% or more and 10 volume% or less. Since the mixed powder is heated and pressurized, in addition to the corrosion resistance to halogen-based corrosive gases and their plasma, a sintered body with excellent conductivity is changed to existing ceramic manufacturing equipment. It can be manufactured inexpensively without adding.

According to still another method for producing a sintered body of the present invention, at least one selected from the group of carbon powder, yttrium nitride powder, yttrium carbide powder, yttrium oxide powder, aluminum oxide powder, zirconium oxide powder, And at least one selected from the group consisting of the carbon powder, yttrium nitride powder, and yttrium carbide powder. The volume of the yttrium oxide powder is 60% by volume. Since the mixed powder having a volume of 95% by volume or less is molded into a molded body and the molded body is fired, the sintered body has excellent conductivity in addition to the corrosion resistance to halogen-based corrosive gas and plasma. Can be manufactured at low cost without any modification to the existing ceramic manufacturing apparatus.

According to still another method for producing a sintered body of the present invention, at least one selected from the group of carbon powder, yttrium nitride powder, yttrium carbide powder, yttrium oxide powder, aluminum oxide powder, zirconium oxide powder, And at least one selected from the group consisting of the carbon powder, yttrium nitride powder, and yttrium carbide powder. The volume of the yttrium oxide powder is 60% by volume. Since the mixed powder of 95 volume% or less is filled in the mold, and this mixed powder is heated and pressurized, the sintered body has excellent conductivity in addition to the corrosion resistance to the halogen-based corrosive gas and these plasmas. Can be manufactured at low cost without any modification to the existing ceramic manufacturing apparatus.

The best mode of the sintered body and the manufacturing method thereof of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

"Sintered body"
The sintered body of the present invention contains at least one selected from the group consisting of metal yttrium, carbon, yttrium nitride, and yttrium carbide, and yttrium oxide. The yttrium oxide constitutes a matrix and is a conductive component. At least one selected from the group of certain metal yttrium, carbon, yttrium nitride, and yttrium carbide constitutes the grain boundary.
This sintered body includes a composite sintered body structure in which a plurality of kinds of metal oxides form a matrix, for example, yttrium oxide and lanthanum oxide, in addition to a normal sintered body structure in which yttrium oxide forms a matrix. It is.
As said carbon, a graphite is suitable.

  In this sintered body, the content of at least one selected from the group of metal yttrium, carbon, yttrium nitride, and yttrium carbide constituting the conductive grain boundary is not particularly limited. If the content is limited in this way, it is preferable because good conductivity can be expressed without impairing the corrosion resistance to halogen-based corrosive gases and their plasmas.

(1) When containing only metal yttrium a. The content of metal yttrium is 0.5 volume% or more and 10 volume% or less b. When the content of yttrium oxide is 60 volume% or more and 99.5 volume% or less (2) When containing any of carbon, yttrium nitride, and yttrium carbide a. Carbon, yttrium nitride, or yttrium carbide content is 5% by volume
More than and 30 volume% or less b. When the content of yttrium oxide is 60% by volume or more and 95% by volume or less (3) When containing two or more of yttrium metal, carbon, yttrium nitride, and yttrium carbide
Although the conductivity improves as the content of the conductive component increases, the corrosion resistance against the halogen-based corrosive gas and these plasmas decreases, so adjust as appropriate to obtain the desired conductivity and corrosion resistance.

In this sintered body, there is no possibility that it becomes a contamination source to the semiconductor wafer or the like, and it is allowed that components other than the above that have excellent corrosion resistance against the halogen-based corrosive gas and these plasmas coexist. Examples of such components include aluminum oxide, zirconium oxide, silicon oxide and the like.
Content of these components should just be in the range which does not impair the corrosion resistance with respect to halogen type corrosive gas and these plasma, Usually, 30 volume% or less is preferable, More preferably, it is 25 volume% or less.
Here, if the content of these components exceeds 30% by volume, the corrosion resistance to halogen-based corrosive gases and their plasmas is lowered, and the characteristics of the matrix, for example, the mechanical strength is significantly lowered. .

The sintered body of the present invention has excellent corrosion resistance against halogen-based corrosive gases and their plasmas, as well as a conductivity of about 1 × 10 ⁻² Ω · cm to 1.0 × 10 ¹⁰ Ω · cm. It has sex.

Next, the sintered body of the present invention will be described in detail by taking as an example the case of using only metal yttrium as the conductive component.
This sintered body contains 0.5% by volume or more and 10% by volume or less of metal yttrium, and 60% by volume or more and 99.5% by volume or less of yttrium oxide, and this yttrium oxide constitutes a matrix. Metal yttrium, which is a conductive component, constitutes the grain boundary.

  Here, the reason why the content of metal yttrium is limited to 0.5% by volume or more and 10% by volume or less is that the content of metal yttrium in the sintered body is less than 0.5% by volume. If the body does not exhibit electrical conductivity and exceeds 10% by volume, the corrosion resistance against halogen-based corrosive gases and their plasmas is reduced, and the proportion of the liquid phase mainly composed of yttrium metal during firing is excessive. This is because the liquid phase oozes out and the composition of the sintered body may become non-uniform.

Also in this sintered body, there is no possibility of becoming a contamination source to the semiconductor wafer or the like, and it is allowed that components other than the halogen-based corrosive gas and metal yttrium having excellent corrosion resistance against these plasmas coexist. Examples of such components include aluminum oxide, zirconium oxide, silicon oxide and the like.
Content of these components should just be in the range which does not impair the corrosion resistance with respect to halogen type corrosive gas and these plasma, Usually, 30 volume% or less is preferable, More preferably, it is 25 volume% or less.
If the content of these components exceeds 30% by volume, the corrosion resistance to halogen-based corrosive gases and their plasmas is lowered, and the characteristics of the matrix, for example, the mechanical strength is significantly lowered.

In this sintered body, it is more preferable that the metal yttrium is 3% by volume or more and 5% by volume or less, and the balance is yttrium oxide and inevitable impurities.
By setting it as such a composition, it becomes a sintered compact which has the outstanding corrosion resistance with respect to halogen type corrosive gas and these plasma, and favorable electroconductivity of about 1 * 10 ^<-2 > ohm * cm.

In this case, the metal yttrium is preferably segregated at the grain boundaries of the yttrium oxide crystal particles constituting the matrix of the sintered body.
When this metal yttrium segregates at the network grain boundaries existing in the sintered body, this metal yttrium forms a continuous conductive path in the sintered body, and the metal yttrium which is a conductive component is reduced. Despite the addition of a small amount, excellent conductivity is exhibited without further impairing the excellent corrosion resistance to halogen-based corrosive gases and these plasmas.

  In addition, since metal yttrium exists at the grain boundaries of the yttrium oxide crystal particles constituting the matrix, the individual particles of metal yttrium are small, and even if they are exhausted by exposure to halogen-based corrosive gases and their plasmas, The generation of coarse particles due to yttrium is suppressed and does not cause generation of particles.

Such a sintered body has a conductivity of about 1 × 10 ⁻² Ω · cm to 1.0 × 10 ¹⁰ Ω · cm, a uniform composition, a halogen-based corrosive gas, and these The corrosion resistance to plasma is further improved.

  For example, oxygen or a fluorine compound is mixed in plasma used in a semiconductor manufacturing process. When oxygen atoms or fluorine atoms excited by plasma come into contact with metal yttrium, metal yttrium is converted into yttrium oxide or yttrium fluoride. To change. These compounds are compounds having the same or similar properties as yttrium oxide constituting the matrix, and therefore, between yttrium oxide constituting the matrix and metal yttrium which is a conductive component segregated at the grain boundary. There is no difference in consumption rate due to plasma irradiation. Therefore, the generation of particles can be prevented, and the size of the generated particles can be reduced even when there is a possibility of the generation.

"Sintered body manufacturing method"
The sintered body of the present invention can be produced by any of the following production methods.
(1) Atmospheric pressure sintering method A mixed powder containing at least one selected from the group of metal yttrium powder, carbon powder, yttrium nitride powder, and yttrium carbide powder and yttrium oxide powder is formed into a molded body, A method of firing the molded body.
(2) Pressure sintering method A mixed powder containing at least one selected from the group consisting of metal yttrium powder, carbon powder, yttrium nitride powder, and yttrium carbide powder and yttrium oxide powder is filled in a mold and mixed. A method of heating and pressurizing powder.

Next, these manufacturing methods will be described in detail.
(1) Pressureless sintering method a. Mixed At least one selected from the group consisting of metal yttrium powder, carbon powder, yttrium nitride powder, and yttrium carbide powder and yttrium oxide powder are weighed in predetermined amounts, and then mixed to obtain a mixed powder.
The content of the conductive component in the mixed powder, the other components allowed to coexist, and the content thereof are as described in the sintered body.

The particle diameter of the metal yttrium powder is not particularly limited, and usually a metal yttrium powder having a particle size of 0.1 μm to 500 μm is used. In addition, the particle size of other conductive components such as carbon powder, yttrium nitride powder, yttrium carbide powder, yttrium oxide powder, and other powders that are allowed to coexist is not particularly limited, and usually 0.1 μm or more. And the thing of a particle size of 10 micrometers or less is used.
As a method for mixing these raw material powders, a known mixing method can be used. For example, a wet mixing method using a ball mill, a vibration mill or the like, or a dry mixing method using an automatic mortar or the like can be used.

b. Molding Fill the above-mentioned mixed powder into a metal mold such as steel and press it up and down using a molding machine (uniaxial pressing) to form a disk, rectangular plate, rectangular parallelepiped, etc. To do.
c. Firing The above-mentioned formed body is fired by holding it at a predetermined maximum holding temperature (firing temperature) for a predetermined time (firing time) in a predetermined atmosphere to obtain a sintered body.

The atmosphere may be an atmosphere in which metal yttrium powder, carbon powder, yttrium nitride powder, yttrium carbide powder or the like is not oxidized, and is an inert atmosphere such as an argon atmosphere or a nitrogen atmosphere, or 5 v / v% H ₂ —N ₂ or the like. The reducing atmosphere is preferred.
The firing temperature is not particularly limited as long as the densification is achieved. For example, when the mixed powder is a mixed powder of metal yttrium and yttrium oxide, the firing temperature is metal yttrium (melting point: 1520 ° C. / A temperature higher than the melting temperature under normal pressure is preferable because a dense sintered body can be obtained.
The firing time is not particularly limited as long as the densification is achieved, but is preferably a time sufficient to make the temperature distribution inside the molded body uniform.

  According to this atmospheric pressure sintering method, a mixed powder containing at least one selected from the group consisting of metal yttrium powder, carbon powder, yttrium nitride powder, and yttrium carbide powder and yttrium oxide powder is molded to form a compact. Since this molded body is fired, the sintered body having excellent conductivity as well as the corrosion resistance to halogen-based corrosive gas and plasma is changed to existing ceramic manufacturing equipment. It can be manufactured inexpensively without adding.

(2) Pressure sintering method a. Mixing The method for producing the mixed powder is exactly the same as the above-mentioned normal pressure sintering method.
b. Heating / Pressing Heating / pressing can be performed by a hot pressing method (HP method), a hot isostatic pressing method (HIP (Hot Isostatic Pressing) method), or the like.
Here, the hot press method (HP method) will be described.
The above mixed powder is filled in a mold made of graphite, alumina, silicon carbide, etc., and this mixed powder is heated simultaneously while being uniaxially pressed to have a predetermined maximum holding temperature (firing temperature) and a predetermined maximum holding pressure (firing pressure). And firing for a predetermined time (firing time) to obtain a sintered body.

According to this pressure sintering method, a mixed powder containing at least one selected from the group of metal yttrium powder, carbon powder, yttrium nitride powder, and yttrium carbide powder and yttrium oxide powder is heated and pressurized, Because it is a sintered body, it has a corrosion resistance to halogen-based corrosive gases and plasmas, and it has a superior electrical conductivity, without any changes to existing ceramic manufacturing equipment. Can be manufactured at low cost.
Furthermore, compared with a normal pressure sintering method, a calcination temperature can be lowered | hung and the sintered compact close | similar to a theoretical density can be produced in a short time. In addition, a sintered body of a hardly sinterable material such as nitride or carbide can be obtained.

Next, the method for producing a sintered body of the present invention will be described in detail by taking as an example the case of using only metal yttrium as the conductive component.
Here, mixed powder containing 0.5% to 10% by volume of metal yttrium and 60% to 99.5% by volume of yttrium oxide is prepared, and the mixed powder is molded and predetermined The formed body is fired at a temperature equal to or higher than the melting temperature of metal yttrium (melting point: 1520 ° C./under normal pressure) to obtain a sintered body.

  Also in this manufacturing method, the content of the conductive component in the mixed powder, other components that are allowed to coexist and the content thereof are as described in the above “sintered body”, and the metal yttrium powder to be used In addition, the particle diameter, sintering method, sintering atmosphere, and the like of the yttrium oxide powder are as described in the above-described sintered body manufacturing method.

Here, the reason why the firing temperature is set to a temperature higher than the melting temperature of metal yttrium is that metal yttrium becomes a liquid phase during the firing process, and enters the solid phase yttrium oxide particles and segregates at the grain boundaries. This is because a dense sintered body can be obtained even at a relatively low temperature as in the case of typical liquid phase sintering.
In addition, since the molten metal yttrium penetrates into the grain boundaries of the yttrium oxide crystal particles constituting the matrix and segregates to form a network-like conductive path, the amount of metal yttrium, which is a conductive component, is small. However, the resistivity of the sintered body can be significantly reduced, and the corrosion resistance of the yttrium oxide to the halogen-based corrosive gas and these plasmas is not reduced.

The melting temperature of metal yttrium varies depending on the pressure change (pressurization or the like) in the firing process, but it is usually only required to be within a temperature range of 1500 ° C to 1800 ° C.
The reason is that if the sintering temperature is less than 1500 ° C., the metal yttrium does not melt in the firing process, and therefore segregates at the grain boundaries of the yttrium oxide crystal particles constituting the matrix to form a conductive path. On the other hand, if the firing temperature exceeds 1800 ° C., the metal yttrium is evaporated and volatilized, and cannot be segregated at the grain boundaries of the yttrium oxide crystal particles constituting the matrix. Because. Also, the sintering energy cost is increased, which is not preferable.

In this manufacturing method, by setting the sintering temperature to be equal to or higher than the melting temperature of metal yttrium, the metal yttrium becomes a liquid phase during the firing process, and in the same way as general liquid phase sintering, dense sintering is performed even at a relatively low temperature. You can get a body.
This molten metal yttrium penetrates into the grain boundaries of the yttrium oxide crystal particles constituting the matrix and segregates to form a network-like conductive path. Therefore, even if the amount of the conductive component added is relatively small, The resistivity of the aggregate can be remarkably lowered, and the excellent corrosion resistance against the halogen-based corrosive gas of yttrium oxide constituting the matrix and these plasmas is not impaired.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely by Examples 1-10 and Comparative Examples 1-3, this invention is not limited by these Examples.

"Production of sintered body"
Example 1
Table 1 shows commercially available yttrium oxide powder (manufactured by Japan Yttrium Co., Ltd., average particle size: 1.5 μm) and commercially available metal yttrium powder (manufactured by Japan Yttrium Co., Ltd., 20 mesh product). It weighed so that it might become a composition ratio, and wet-mixed in the ethanol solvent using the planetary ball mill.
The obtained mixed powder was uniaxially pressed and then sintered under normal pressure at a firing temperature of 1550 ° C. in an argon (Ar) atmosphere for 2 hours, and a disc-shaped metal yttrium-containing yttrium oxide having a diameter of 60 mm and a thickness of 8 mm. A sintered body was obtained.

(Examples 2 to 7)
The metal yttrium-containing yttrium oxide sintered bodies of Examples 2 to 7 were obtained according to Example 1 except that the composition ratio was changed as shown in Table 1.

(Example 8)
A graphite-containing yttrium oxide sintered body of Example 8 was obtained according to Example 1, except that the metal yttrium powder was changed to a commercially available graphite powder (manufactured by Tokai Carbon Co., Ltd., average primary particle size: 30 nm). .

Example 9
The yttrium nitride-containing yttrium oxide sintered body of Example 9 was obtained according to Example 1 except that the metal yttrium powder was changed to yttrium nitride powder (average particle size: 0.2 μm).

(Example 10)
The yttrium carbide-containing yttrium oxide sintered body of Example 10 was obtained according to Example 1 except that the metal yttrium powder was changed to yttrium carbide powder (average particle size: 0.2 μm).

(Comparative Examples 1-3)
Except that the composition ratio was changed as shown in Table 1, the metal yttrium-containing yttrium oxide sintered bodies of Comparative Examples 1 to 3 were obtained according to Example 1.

"Evaluation of sintered body"
The volume resistivity (Ω · cm) of the sintered bodies of Examples 1 to 10 and Comparative Examples 1 to 3 and the relative density of the sintered bodies were measured, and the corrosion resistance was examined.
Moreover, about Examples 1-7 and Comparative Examples 2 and 3, the composition analysis of the matrix grain boundary was implemented and the precipitation state of the metal yttrium in a grain boundary was investigated.
The above evaluation results are shown in Table 1.

The evaluation method is as follows.
(1) Volume resistivity value Japanese Industrial Standard: Measured according to the method defined in JIS C2141.
(2) the true density of the relative density sintered body of _{(d 0)} was measured by the Archimedes method, it represents the ratio _(d 0 / _{d r)} with respect to the theoretical density _{(d r)} of the true density _{(d 0)} in percentage, Relative density (%) was used.

(3) Corrosion resistance A mixed gas composed of CF ₄ (20 vol%) and O ₂ (80 vol%) is introduced into a chamber under reduced pressure (1.0 torr) and exposed to plasma generated for 10 hours to scan the exposed surface. Surface roughness was evaluated by observation using a scanning electron microscope (SEM).
The evaluation criteria are as follows.
○: Surface roughness is not recognized Δ: Surface roughness is slightly recognized ×: Surface roughness is recognized

(4) Precipitation state of metal yttrium One surface of the sintered body is mirror-polished, and the composition of the mirror-polished surface is analyzed using an electron beam microanalyzer (EPMA). Evaluated.
The evaluation criteria are as follows.
A: A small amount of metal yttrium segregates and precipitates intermittently.
B: A large amount of metal yttrium is segregated and continuously deposited.

According to these evaluation results,
The sintered bodies of Examples 1 to 10 were found to be excellent in conductivity, although the corrosion resistance was substantially the same as that of the sintered bodies of Comparative Examples 1 and 2.
Moreover, it turned out that the sintered compact of Examples 1-10 is excellent in corrosion resistance compared with the sintered compact of the comparative example 3.

FIG. 1 is a scanning electron microscope image (SEM image) showing a mirror-polished surface when the surface of a sintered metal yttrium-containing sintered body in Example 5 is mirror-polished. Here, the magnification was 1000 times.
According to this SEM image, it was found that metal yttrium was segregated at the grain boundaries of the yttrium oxide crystal particles, and a network-like continuous conductive path was formed by the segregated metal yttrium.

  The sintered body of the present invention contains at least one selected from the group consisting of metal yttrium, carbon, yttrium nitride, and yttrium carbide, which are conductive components, and yttrium oxide constituting the matrix, thereby causing halogen-based corrosion. As a structural member in semiconductor manufacturing equipment, as well as etching electrodes, dielectric materials for electrostatic chucks, etc., semiconductor manufacturing The present invention can be applied to various members that are simultaneously required to have corrosion resistance and conductivity other than the apparatus, and its usefulness is very large.

It is a SEM image which shows the surface state of the metal yttrium containing yttrium oxide sintered compact of Example 5 of this invention.

Claims (7)

It consists of metal yttrium and yttrium oxide,
A sintered body characterized in that the content of the metal yttrium is 0.5 vol% or more and 10 vol% or less. And at least one selected from the group consisting of carbon, yttrium nitride, and yttrium carbide, and yttrium oxide, and at least one of aluminum oxide, zirconium oxide, and silicon oxide,
Sintering characterized in that at least one selected from the group consisting of carbon, yttrium nitride and yttrium carbide is 5% by volume to 30% by volume, and the yttrium oxide is 60% by volume to 95% by volume. body. The sintered body according to claim 1, wherein the metal yttrium is segregated at grain boundaries. Forming a mixed powder composed of a metal yttrium powder and an yttrium oxide powder, the content of the metal yttrium powder being 0.5 volume% or more and 10 volume% or less to form a molded body, and firing the molded body The manufacturing method of the sintered compact characterized by these. Filling a mold with mixed powder consisting of metallic yttrium powder and yttrium oxide powder, the content of the metallic yttrium powder being 0.5 volume% or more and 10 volume% or less, and heating and pressing this mixed powder The manufacturing method of the sintered compact characterized by these. And at least one selected from the group consisting of carbon powder, yttrium nitride powder, and yttrium carbide powder, and yttrium oxide powder, and aluminum oxide powder, zirconium oxide powder, and silicon oxide powder.
A mixed powder in which at least one selected from the group consisting of the carbon powder, yttrium nitride powder, and yttrium carbide powder is 5% by volume to 30% by volume, and the yttrium oxide powder is 60% by volume to 95% by volume. A method for producing a sintered body, characterized in that the green body is molded into a molded body and the molded body is fired. And at least one selected from the group consisting of carbon powder, yttrium nitride powder, and yttrium carbide powder, and yttrium oxide powder, and aluminum oxide powder, zirconium oxide powder, and silicon oxide powder.
A mixed powder in which at least one selected from the group consisting of the carbon powder, yttrium nitride powder, and yttrium carbide powder is 5% by volume to 30% by volume, and the yttrium oxide powder is 60% by volume to 95% by volume. A method for producing a sintered body, comprising filling a mold and heating and pressing the mixed powder.

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