KR20070095211A - Ceramic coating member for semiconductor processing apparatus - Google Patents

Abstract

A ceramic coating member used as a member or a part disposed in a semiconductor processing container to perform a plasma etching process in a corrosive gas atmosphere, and a member which has an excellent durability to plasma erosion in a corrosive gas atmosphere, can suppress the formation of contaminants(particles) and lessens a load for maintaining an apparatus are provided. A ceramic coating member for a semiconductor processing apparatus comprises: a substrate; a porous layer coated on a surface of the substrate and formed of an oxide of an element in Group IIIa of the periodic table of the elements; and a secondary recrystallized layer of the oxide formed on the porous layer. The ceramic coating member comprises an undercoat is disposed between the substrate and the porous layer. The substrate is (1) aluminum and an alloy thereof, titanium and an alloy thereof, stainless steel and other special steels, Ni-based alloy, and other metals and alloys thereof, (2) a ceramic of quartz, glass or an oxide or a carbide, a boride, a silicide, a nitride or a mixture thereof, (3) a cermet of the ceramic and the metal or alloy, (4) plastics, and (5) a metal plating(electroplating, fusion plating, chemical plating) or a metal deposition film formed on surfaces of the materials (1) to (4). The porous layer is an oxide layer of Sc, Y or a lanthanide of atom number 57 to 71(La, Ce, Pr, Nb, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu).

Description

Ceramic Coating Member for Semiconductor Processing Apparatus {Ceramic Coating Member for Semiconductor Processing Apparatus}

1 is a partial sectional view of a portion (a) of a member having a conventional thermal spray coating, a member (b) formed by forming a secondary recrystallization layer in the outermost layer, and a member (c) having a lower coat;

Fig. 2 is an X-ray diffraction diagram of a secondary recrystallized layer produced when the sprayed coating (porous layer) is subjected to electron beam irradiation.

3 is Y ₂ O ₃ before electron beam irradiation; X-ray diffraction diagram of thermal sprayed coating.

4 is an X-ray diffraction diagram of a secondary recrystallized layer after an electron beam irradiation process.

<Explanation of symbols for main parts of the drawings>

1: description

2: porous layer (spray particle deposition layer)

3: pore (void)

4: particle interface

5: through pore

6: secondary recrystallization layer

7: lower coat

[Document 1] Japanese Unexamined Patent Application Publication No. 10-4083

[Document 2] Japanese Unexamined Patent Publication No. 2001-164354

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic covering member for semiconductor processing apparatus, and is particularly suitably used as a covering member such as a member and a component disposed in a semiconductor processing container for performing a plasma etching process or the like.

Devices used in the fields of semiconductors and liquid crystals are often processed using plasma energy of highly corrosive halogen-based corrosion gases when processing them. For example, a fine wiring pattern formed by a semiconductor processing device generates plasma in a highly corrosive gas atmosphere of fluorine or chlorine or a mixed gas atmosphere of such a gas and an inert gas. It is formed by fine processing (etching) using strong reactivity.

In such a processing technique, members or parts (such as susceptors, electrostatic chucks, electrodes, etc.) disposed in at least part or the inside of the wall of the reaction vessel are easily subjected to corrosion by plasma energy, thereby providing excellent plasma corrosion resistance. It is important to use the material. As a material which can comply with such a request, inorganic materials, such as metal (including alloy) with good corrosion resistance, quartz, and alumina, have conventionally been used. For example, Japanese Patent Application Laid-Open No. 10-4083 discloses coating an inorganic material on the surface of a member in the reaction vessel by PVD or CVD, or forming a dense film made of an oxide of group IIIa element of the periodic table. Or Y ₂ O ₃ A method of coating a single crystal is disclosed. Japanese Unexamined Patent Application Publication No. 2001-164354 discloses a technique for improving plasma corrosion resistance by coating Y ₂ O ₃ , which is an oxide of an element belonging to group IIIa of the periodic table, with a thermal spraying method.

However, the conventional method of coating oxides of group IIIa elements and the like is not a sufficient measure in the field of the recent semiconductor processing technology in which high precision processing and environmental cleanliness are required in a more severe corrosive gas atmosphere.

In addition, Y ₂ O ₃ disclosed in Document 2 Considering that the member coated with the thermal spray coating is processed under the harsh conditions that the processing of the semiconductor member in recent years uses a fluorine-based gas and a hydrocarbon-based gas alternately in addition to the plasma etching action of higher output. Improvement is needed.

For example, the F-containing gas atmosphere generates fluoride with high vapor pressure due to the strong corrosion reaction peculiar to halogen gas, while in the CH-containing gas atmosphere, decomposition is accelerated or formed by fluorine compounds generated in the F-containing gas. Some of the components are converted to carbides, further increasing the reaction of fluoride. In addition, since the above reaction is promoted in a plasma environment in an F-containing gas atmosphere, it becomes a very severe corrosive environment. Alternatively, under such circumstances, particles, which are corrosion products, are generated, which drop onto the surface of the integrated circuit of the semiconductor product, which causes device damage.

The main object of this invention is to propose the ceramic coating member used as a member, a component, etc. which are arrange | positioned in the semiconductor processing container used for plasma etching process in a corrosive gas atmosphere.

Another object of the present invention is to provide a member having excellent durability against plasma corrosion in a corrosive gas atmosphere, suppressing generation of contaminants (particles) and reducing maintenance load of the apparatus.

As a means for realizing the above object, the present invention provides a semiconductor comprising a substrate, a porous layer composed of an oxide of group IIIa element of the periodic table coated on the surface of the substrate, and a secondary recrystallized layer of the oxide provided on the porous layer. A ceramic covering member for a processing apparatus is proposed.

The more preferable solution of this invention is to set it as the structure which has a lower coat between a base material and a porous layer.

More preferred solution of the present invention is that the base material is ① aluminum and its alloys, titanium and its alloys, stainless steel, other special steels, Ni-based alloys, other metals or their alloys, ② quartz, glass or oxides or carbides, Borides, silicides, nitrides and ceramics composed of these mixtures, (3) cermets consisting of the ceramics and the above metals and alloys, (4) plastics, (5) metal plating on the surfaces of the above materials (1) to (4) (electroplating, hot dip plating, chemical plating). One of them is a metal vapor deposition film.

A more preferable solution of the present invention is that the porous layer is Sc, Y or lanthanides (La, Ce, Pr, Nb, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er having an atomic number of 57 to 71). , Tm, Yb, Lu).

A more preferable solution of the present invention is that the porous layer comprises a thermal sprayed coating having a porosity of about 5 to 20% having a layer thickness of about 50 to 2000 µm.

A more preferable solution of the present invention is a high energy irradiation treatment layer in which the secondary recrystallization layer is secondaryly transformed by a high energy irradiation treatment to form a primary transformed oxide.

A more preferable solution of the present invention is a layer having a porosity of less than 5% in which a porous layer containing tetragonal crystals is secondary transformed by a high energy irradiation treatment to form tetragonal structure.

A more preferable solution of the present invention is that the secondary recrystallized layer is a layer in which a primary transformed sprayed coating of yttrium oxide composed of cubic crystal and monoclinic crystal is secondary transformed into a cubic crystal by a high energy irradiation treatment.

A more preferable solution of the present invention is that the secondary recrystallized layer has a maximum roughness (Ry) of about 6 to 16 µm, an average roughness (Ra) of about 3 to 6 µm, and a 10-point average roughness (Rz) of 8 To about 24 μm.

The more preferable solution of this invention is having a layer thickness of about 100 micrometers or less.

According to a more preferable solution of the present invention, the high energy irradiation process is any one of electron beam irradiation and laser beam irradiation.

A more preferable solution of the present invention includes any one or more ceramics, the metals and alloys of which the lower coat is selected from Ni, Al, W, Mo, Ti and alloys thereof, oxides, nitrides, borides and carbides. It is a film in which at least 1 sort (s) chosen from the cermet which consists of said ceramics was formed in the thickness of about 50-500 micrometers.

The ceramic coating member for semiconductor processing apparatuses of the present invention having the above-described structure is a plasma in an atmosphere containing a halogen compound gas and / or an atmosphere containing a hydrocarbon-based gas, particularly in a corrosive environment in which both of these atmospheres are alternately repeated. It exhibits strong resistance to corrosion for a long time and is excellent in durability.

In addition, the ceramic coating member of the present invention is less likely to generate fine particles composed of constituents of the coating film or the like generated in the plasma etching process under the corrosive environment, and does not cause environmental pollution. Therefore, it is possible to efficiently produce high quality semiconductor elements and the like.

In addition, according to the present invention, since contamination by particles is reduced, the cleaning operation of the semiconductor processing apparatus or the like is reduced, contributing to the improvement of productivity. In addition, according to the present invention, the above-described effects can be obtained, so that the plasma output can be increased to increase the etching effect and the speed. Therefore, the overall semiconductor production system can be improved by miniaturization and weight reduction of the apparatus. There is an effect.

The ceramic coating member for semiconductor processing apparatus of this invention functions most effectively when a semiconductor element is used for members, components, etc. which are exposed to a plasma etching processing environment in a corrosive gas atmosphere. Such an environment is severely corroded by members and the like, and particularly, these members include fluorine or a fluorine compound (hereinafter, these are referred to as "F-containing gas") atmospheres such as SF ₆ , CF ₄ , Atmosphere containing gases such as CHF ₃ , ClF ₃ , HF or C ₂ H ₂ , CH ₄ Hydrocarbon-based gas (hereinafter, these are referred to as "CH-containing gas") atmospheres, or an atmosphere in which both of these atmospheres are alternately repeated.

The F-containing gas atmosphere, there is a case mainly contains a fluorine or fluorine compound, or comprising oxygen (O _2). Fluorine is particularly rich in reactivity (highly corrosive) among the halogen elements, and metals are originally characterized by reaction of both oxides and carbides to produce corrosion products having high vapor pressure. Therefore, the metal, oxide, carbide, etc. in the F-containing gas atmosphere do not produce a protective film for suppressing the progress of the corrosion reaction on the surface, and the corrosion reaction proceeds indefinitely. However, although described in detail below, even in such an environment, elements belonging to group IIIa of the periodic table, that is, Sc and Y, elements having atomic numbers 57 to 71, and oxides thereof exhibit relatively good corrosion resistance.

On the other hand, the CH-containing gas atmosphere has no strong corrosiveness to the CH itself, but has a characteristic that a reduction reaction that is completely opposite to the oxidation reaction proceeding in the F-containing gas atmosphere occurs. Therefore, the metal and metal compound which show comparatively stable corrosion resistance in F containing gas atmosphere, when they contact CH-containing gas atmosphere, chemical bonding force becomes weak. When the portion in contact with the CH-containing gas is further exposed to the F-containing gas atmosphere, it is considered that the initial stable compound film is chemically destroyed and finally, the corrosion reaction proceeds.

In particular, in an environment in which plasma is generated in addition to the change of the atmospheric gas, both F and CH are electrolyzed to generate highly reactive F and CH, and thus, corrosiveness and reducibility are further increased and corrosion products are easily generated.

In this way, the resulting corrosion product vaporizes in the plasma environment or becomes fine particles which significantly contaminate the plasma processing vessel. Therefore, in the present invention, it is particularly effective as a countermeasure against corrosion in an environment in which an F-containing gas / CH-containing atmosphere is alternately repeated, and is thought to be useful not only in preventing generation of corrosion products but also in suppressing particle generation.

Next, the inventors examined the material which shows favorable corrosion resistance and environmental pollution resistance together in the atmosphere of F containing gas or CH containing gas first. As a result, it was concluded that in the present invention, an oxide of an element belonging to group IIIa of the periodic table is effective as a material used by coating the surface of the substrate. Specifically, oxides of Sc, Y or lanthanides (La, Ce, Pr, Nb, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) having an atomic number of 57 to 71 Among them, rare earth oxides of La, Ce, Eu, Dy, and Yb are suitable for the lanthanide. In this invention, these oxide can be used individually or in mixture of 2 or more types, a complex oxide, and a process material. In the present invention, the reason for focusing on the metal oxide is because it is excellent in halogen resistance and plasma corrosion resistance compared to other oxides.

In the ceramic coating member of the present invention, as a substrate,

① aluminum and its alloys, titanium and its alloys, stainless steel, other special steels, Ni-based alloys, other metals or their alloys,

(2) quartz, glass, or ceramics consisting of oxides, carbides, borides, silicides, nitrides, and mixtures thereof;

(3) a cermet consisting of the ceramic and the metal and alloy,

④ plastic,

(5) Metal plating (electroplating, hot dip plating, chemical plating) or a metal vapor deposition film formed on the surface of the materials ① to ④ may be used.

As is apparent from the above-mentioned part, the characteristic of this invention is to coat | cover the oxide of group IIIa element of a periodic table which shows the outstanding corrosion resistance, environmental pollution resistance, etc. in a corrosive environment on the surface of the said base material. As a means of the coating, in the present invention, the method described below is adopted.

That is, in this invention, the spraying method is used as a suitable example as a method of forming the film of the porous layer of predetermined thickness on the surface of a base material. Therefore, in this invention, the oxide of group IIIa element is made into the spraying material powder which consists of granules of the particle size of 5-80 micrometers by grinding | pulverization etc. first, and the thermal spraying material powder is sprayed by the predetermined method on the surface of a base material, A porous layer made of a porous spray coating having a thickness of 2000 μm is formed.

In addition, as a method of thermally spraying the oxide powder, an atmospheric plasma spraying method and a reduced pressure plasma spraying method are preferable, but a water plasma spraying method or an explosion spraying method may be applied depending on the use conditions.

The thermal sprayed coating (porous layer) obtained by thermally spraying the oxide powder of group IIIa element, when its thickness is less than 50 µm, does not have sufficient performance as a coating under the corrosive environment, while the thickness of this layer exceeds 2000 µm. As a result, the mutual bonding force of the sprayed particles is weakened, and as a result, the stress generated during the film formation (which is thought to be the main cause of the volume shrinkage due to the rapid cooling of the particles) becomes large, and the film easily breaks.

Further, the porous layer (sprayed coating) forms a lower coat directly or in advance on the substrate, and then forms a thermal sprayed coating of the oxide on the lower coat.

The lower coat is preferably formed of a metallic coating such as Ni and its alloys, Co and its alloys, Al and its alloys, Ti and its alloys, Mo and its alloys, W and its alloys, Cr and its alloys, by thermal spraying or vapor deposition. The film thickness is preferably about 50 to 500 m.

The role of the lower coat is to block the surface of the substrate from the corrosive environment to improve corrosion resistance and to improve the adhesion between the substrate and the porous layer. Therefore, if the film thickness of this lower coat is less than 50 micrometers, sufficient corrosion resistance cannot be obtained but uniform film formation is difficult. On the other hand, even if the film thickness is made thicker than 500 micrometers, the effect of corrosion resistance will be saturated.

The porous layer formed of the thermal sprayed coating made of an oxide of an element belonging to group IIIa has an average porosity of about 5 to 20%. This porosity also depends on the kind of thermal spraying method, for example, which thermal spraying methods, such as a reduced pressure plasma spraying method and an atmospheric plasma spraying method, are employ | adopted. Preferably, the range of average porosity is about 5 to 10%. If the porosity is less than 5%, the relaxation effect of the thermal stress accumulated in the film is poor in thermal shock resistance, while if it exceeds 10%, in particular 20%, the corrosion resistance and plasma corrosion resistance are poor.

The surface of this porous (sprayed coating) has an average roughness (Ra) of about 3 to 6 µm, a maximum roughness (Ry) of about 16 to 32 µm, and a 10-point average roughness (Rz) of 8 To about 24 μm roughness.

In the present invention, the porous layer is used as a thermal sprayed coating. The reason why such a coating is not only excellent in thermal shock resistance, but also that a coating layer having a predetermined thickness can be obtained in a short time and inexpensively. Alternatively, such a coating has a buffering effect of alleviating thermal shock applied to the dense secondary recrystallized layer of the upper layer to alleviate thermal shock applied to the entire coating. According to this meaning, the composite coating formed by arranging the thermal spray coating on the lower layer and forming the secondary recrystallization layer on the upper layer produces an effect of synergistically acting to improve the durability as the coating.

The most characteristic constitution in the present invention is a new layer, ie, in the form of altering a part of the outermost layer of the sprayed coating, for example, on the porous sprayed coating made of the oxide of the group IIIa element. A secondary recrystallization layer is provided by secondary transformation of a porous layer made of an oxide of group IIIa element.

In general, in the case of a metal oxide of a Group IIIa element, for example yttrium oxide (yttria: Y ₂ O ₃ ), the crystal structure is a cubic crystal belonging to a tetragonal system. Plasma spraying the powder of yttrium oxide (hereinafter referred to as "yttria") causes the crystal structure to collide and deposit on the surface of the substrate while supermelting the molten particles at high speed toward the substrate. In addition to cubic cubic (Cubic) cubic system (Cubic) is a crystalline form consisting of a mixed crystal containing monoclinic monoclinic (monoclinic) of the primary transformation.

That is, the crystalline form of the porous layer is formed by a crystalline form composed of a mixed crystal including a tetragonal system and a tetragonal system by primary transformation by supercooling at the time of thermal spraying.

On the other hand, the secondary recrystallized layer is a layer in which the crystalline form consisting of the above-mentioned primary crystals is secondary transformed into a tetragonal crystalline form.

As described above, in the present invention, the porous layer of the group IIIa oxide composed mainly of a mixed crystal structure containing primarily transformed tetragonal crystals is subjected to high energy irradiation, thereby heating the deposited spray particles of the porous layer to at least the melting point or more. The layer was transformed (secondary transformation) again to return the crystal structure to the tetragonal structure and crystallographically stabilized.

At the same time, in the present invention, the thermal distortion and mechanical distortion accumulated in the thermal spray particle deposition layer during the first transformation by thermal spraying are released, thereby physically and chemically stabilizing its properties, and Densification and smoothing were also realized. As a result, the secondary recrystallized layer made of the group IIIa metal oxide becomes a dense and smooth layer as compared with the layer in the thermal sprayed state.

Thus, the secondary recrystallized layer becomes a densified layer having a porosity of less than 5%, preferably less than 2%, while the surface is 0.8 to 3.0 mu m at an average roughness Ra and 6 to 16 mu m at a maximum roughness Ry. And 10-point average roughness Rz, it becomes about 3-14 micrometers, and it becomes a remarkably different layer compared with a porous layer. In addition, control of this maximum roughness Ry is determined from the viewpoint of environmental pollution resistance. The reason is that when the surface of the member in the container is scraped off and generated particles by plasma ions or electrons excited in the etching processing atmosphere, the influence is well represented by the value of the maximum roughness Ry of the surface. If the value is large, the chance of particle generation increases.

Next, the high-energy irradiation method performed in order to form the said secondary recrystallization layer is demonstrated. How to employ the present invention is suitable for the laser irradiation process such as electron beam irradiation treatment, CO ₂ or YAG.

As a condition of the electron beam irradiation treatment, it is recommended to introduce an inert gas such as Ar gas into the irradiation chamber in which the air is exhausted, and to treat it under the conditions shown below, for example.

Irradiation atmosphere: 0.0005 to 10 ㎩

Beam irradiation power: 0.1 to 8 Hz

Processing speed: 1 to 30 kPa

Of course, such conditions are not limited to the above ranges, and as long as the predetermined effects of the present invention can be obtained, they are not limited to these conditions only.

The oxide of the group IIIa element subjected to the electron beam irradiation is elevated in temperature from the surface, and finally reaches a melting point or more to become a molten state. Since the melting phenomenon is carried out to the inside of the film in order by increasing the electron beam irradiation output, increasing the number of irradiation, or increasing the irradiation time, the depth of the irradiation melt layer can be controlled by changing these irradiation conditions. If there is a melting depth of 100 µm or less and practically 1 µm to 50 µm, a secondary recrystallization layer suitable for the above object of the present invention is obtained.

As a laser beam irradiation, a YAG laser using a YAG crystal, or CO ₂ when the medium is a gas It is possible to use a gas laser or the like. As this laser beam irradiation process, the conditions shown below are recommended.

Laser power: 0.1 to 10 Hz

Laser beam area: 0.01 to 2500 mm2

Processing speed: 5 to 1000 mm / s

As described above, the electron beam irradiation treatment or laser beam irradiation treatment layer is transformed into a crystalline form that is transformed into a physicochemically stable crystal by cooling at a high temperature and depositing a secondary recrystallization at the time of cooling. Proceed. For example, Y ₂ O ₃ formed by atmospheric plasma spraying As described above, the coating is a mixed crystal containing tetragonal crystals in a sprayed state, but most of the coating is changed into cubic crystals after electron beam irradiation.

Hereinafter, the characteristic of the secondary recrystallization layer which consists of an oxide of the periodic table IIIa element of the high energy irradiation process is integrated, as follows.

a. The secondary recrystallized layer produced by the high energy irradiation treatment is a secondary transformation of a porous layer made of a metal oxide, etc., which is a lower primary transformation layer, or the oxide particles of the lower layer are heated above the melting point, so that at least some of the pores Is extinguished and densified.

b. The secondary recrystallized layer produced by the high energy irradiation treatment is a layer obtained by further transforming the porous layer made of the lower metal oxide, and when it is a thermal spray coating formed by thermal spraying, the unmelted particles during thermal spraying are also completely Melted and the surface is in a mirror state, the projections easily prone to plasma etching disappear. That is, in the case of the porous layer, the maximum roughness Ry is 16 to 32 μm, but the maximum roughness Ry of the secondary recrystallized layer subjected to this treatment is a remarkably smooth layer of about 6 to 16 μm, and the plasma etching is performed. Generation of particles, which is a cause of contamination during processing, is suppressed.

c. Through the effects of a and b, the porous layer is blocked by the through pores due to the secondary recrystallized layer produced by the high energy irradiation treatment, and there is no corrosive gas penetrating into the interior (substrate) through these through pores. In addition to improving the corrosion resistance, the densified resin exhibits strong resistance to plasma etching, and exhibits excellent corrosion resistance and plasma corrosion resistance over a long period of time.

d. Since the secondary recrystallized layer has a porous layer thereunder, the porous layer functions as a layer having excellent thermal shock resistance, and also serves as a buffer region, and thermal shock applied to the upper densified secondary recrystallized layer. Through the action of mitigating, the effect of softening the thermal shock applied to the entire film formed on the surface of the substrate is produced. In particular, when the porous layer and the secondary recrystallized layer are laminated to form a composite layer, the effect is complex and synergistic.

The secondary recrystallized layer produced by the high energy irradiation treatment is preferably a layer having a thickness of 1 µm or more and 50 µm or less from the surface. The reason for this is that when the thickness is less than 1 m, there is no effect of film formation. On the other hand, when the thickness is more than 50 m, the burden of high-energy irradiation treatment is increased and the effect of film deposition is saturated.

(Example 1)

In the present experimental example, the state of the film formation of the thermal spraying by the oxide of the group IIIa element and the state of the layer formed when the obtained film was subjected to electron beam irradiation and laser beam irradiation were examined. In addition, oxides of Group IIIa for the test are seven kinds of oxide powders of Sc ₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ , CeO ₂ , Eu ₂ O ₃ , Dy ₂ O ₃ and Yb ₂ O ₃ (average Particle diameter: 10 to 50 µm). Then, these powders were sprayed at 100 μm by directly atmospheric plasma spraying (APS) and reduced pressure plasma spraying (LPPS) on one surface of an aluminum test piece (dimensions: width 50 mm × length 60 mm × thickness 8 mm). A film was formed. Then, the surface of these films was subjected to the electron beam irradiation process and the laser beam irradiation process. Table 1 summarizes the results of this test.

In addition, the thermal spraying of the lanthanide-based metal oxides of atomic numbers 57 to 71 has not been reported so far in the test of the thermal spraying method of the group IIIa element, and the formation of a film suitable for the purpose of the present invention and the electron beam irradiation This is to check whether there is an application effect.

According to the test results, as shown in the melting point (2300 to 2600 ° C.) of Table 1, even if the gas plasma heat source melts well enough, the pores peculiar to the oxide thermal spray coating exist, but the film is relatively good. there was. In addition, the electron beam irradiation and the laser beam irradiation of these coating surfaces confirmed that the projections disappeared by the melting phenomenon in all the coatings and were changed into a dense and smooth surface as a whole.

TABLE 1

(Example 2)

This experiment example, for a high thermal sprayed coating of from among energy irradiation processed specimen Y ₂ O ₃ prepared in the above Test 1, a thermally sprayed coating section according to the longitudinal electron beam irradiation treatment of the coating film was observed by an optical microscope The microstructural change of the film caused by the high energy irradiation treatment was observed.

1 is Y ₂ O ₃ It shows typically the microstructure change in the vicinity of the surface in the thermal spray coating (porous membrane), the composite | film | coat after the electron beam irradiation process, and the composite coating which has a lower coat layer. In the non-irradiated test piece shown in Fig. 1A, it can be seen that the sprayed particles constituting the coating are present independently, and the surface roughness is large. On the other hand, a new layer having different microstructures is formed on the thermal spray coating by the electron beam irradiation process shown in Fig. 1B. This layer is a dense layer in which the thermal spray particles are fused to each other and have few voids. 1C shows an example having a lower coat.

On the other hand, under the dense layer produced by electron beam irradiation, a film with many pores unique to the thermal spray coating existed, and it was confirmed that it became a layer excellent in thermal shock resistance.

(Example 3)

This experimental example, Y ₂ O ₃ of Figure 1 (a) XRD measurement of the porous layer which is a sprayed coating and the secondary recrystallization layer shown in FIG.1 (b) produced | generated by the electron beam irradiation process on the following conditions is carried out to investigate the crystal structure of each layer. Fig. 2 shows the result and shows the XRD pattern before the electron beam irradiation process. 3 is an X-ray diffraction chart which enlarged the longitudinal axis before a process, and FIG. 4 is an X-ray diffraction chart which enlarged the vertical axis after a process. As can be seen from Fig. 3, the peak before the treatment is observed in the range of 30 to 35 °, and the cubic crystal and the single crystal are mixed in particular. In contrast, as shown in FIG. 4, the secondary recrystallized layer subjected to electron beam irradiation is Y ₂ O _3. The peak representing the particles became sharp, the peak of the monoclinic was attenuated, and the surface indices 202, (3/0), and the like could not be confirmed, and only cubic crystals were confirmed. In addition, this test is measured using the RINT1500 X-ray diffraction apparatus by Rigaku Denki Corporation.

X-ray diffraction conditions

40 ㎸ output

Scanning speed 20 / min

In Fig. 1, reference numeral 1 denotes a substrate, 2 a porous layer (spray particle deposition layer), 3 a pore (pore), 4 a particle interface, 5 a through pore, and 6 a secondary recrystallization produced by an electron beam irradiation process. Layer, and 7 is the bottom coat. Moreover, as a result of observing using an optical microscope also by a laser beam irradiation process, the microstructure change similar to an electron beam irradiation surface is recognized.

(First embodiment)

In this embodiment, a lower coat (spray coating) of 80 mass% Ni-20 mass% Cr is formed on the surface of an Al substrate (dimensions: 50 mm x 50 mm x 5 m) by an atmospheric plasma spraying method, and Y is placed thereon. Using a powder of ₂ O ₃ and CeO ₂ , a porous film was formed by atmospheric plasma spraying, respectively. Thereafter, two types of high-energy irradiation treatments, such as electron beam irradiation and laser beam irradiation, were performed on the surface of such a thermal spray coating. Next, the surface of the test agent obtained in this way was subjected to plasma etching processing under the following conditions. Then, plasma corrosion resistance and environmental pollution characteristics were investigated by measuring the particle number of particles of the film component shaved and scattered by the etching treatment. Particles were compared by measuring the time until the number of particles having a particle size of 0.2 µm or more adhering to the surface of a silicon wafer having a diameter of 8 inches placed unmovably in this container reached 30.

(1) atmospheric gas and flow conditions

CHF ₃ / O ₂ / Ar = 80/100/160 (F / cm 3 per minute) as F-containing gas

C ₂ H ₂ / Ar = 80/100 as CH-containing gas (flow rate cm 3 per minute)

(2) plasma irradiation output

High Frequency Power: 1300 W

Pressure: 4 ㎩

Temperature: 60 ℃

(3) plasma etching test

a. Implementation in F-containing gas atmosphere

b. Implementation in CH-containing gas atmosphere

c. F-containing gas atmosphere 1h 실시 Conducted in an atmosphere in which CH-containing gas atmosphere 1h is alternately repeated

The test results are shown in Table 2. As is clear from the results shown in this table, the amount of particles generated by corrosion of the test coating was more treated in the F-containing gas atmosphere than the CH-containing gas atmosphere, and the time for reaching the number of particles of 30 was short. However, when the plasma etching environment was configured while alternately repeating both gases, the amount of particles generated was further increased. This cause is caused by the repetition of the fluorination (oxidation) reaction of the coating surface particles in the F-containing gas and the reduction reaction in the CH-containing gas atmosphere, thereby impairing the chemical stability of the coating surface particles. On the other hand, it is considered that the fluoride of the relatively stable coating component is easily scattered by the plasma etching effect.

On the other hand, in the case of the test coating obtained by electron beam irradiation or laser beam irradiation treatment, even if the conditions of the F-containing gas and the CH-containing gas are alternately repeated, the amount of particles scattered is very small, indicating excellent plasma corrosion resistance. I could confirm that.

In addition, although the main component of the particle | grains adhering to the silicon wafer surface was Y (Ce), F, C in the state of thermal spraying, the film | membrane which made this film the electron beam irradiation or the laser beam irradiation (made of secondary recrystallization layer), The film component was hardly recognized in the generated particle | grains, and was F and C.

TABLE 2

(2nd Example)

In the present Example, the film-forming material as shown in Table 3 was sprayed on the surface of Al base material of 50 mm x 100 mm x 5 mm thickness, and the film was formed. After that, part of the electron beam irradiation treatment was performed to form a secondary recrystallization layer suitable for the present invention. Next, after cutting the test piece of dimension 20mm * 20mm * 5mm from the obtained test material, another part was masked so that the range of 10mm * 10mm of the irradiated coating surface may be exposed, and it shows below. Plasma irradiation was carried out under the conditions, and the amount of damage due to plasma corrosion was determined by an electron microscope or the like.

(1) gas atmosphere and flow conditions

CF ₄ / Ar / O ₂ = 100/1000/10 ml (flow rate per minute)

(2) plasma irradiation output

High Frequency Power: 1300 W

Pressure: 133.3 ㎩

Table 3 summarizes the above results. As is clear from the results shown in this table, the anodic oxide film (No. 8), the B ₄ C sprayed coating (No. 9), and quartz (No treatment No. 10) of the comparative example are all not practical because of large wear amount due to plasma corrosion. I could see that.

On the other hand, the coating (numbers 1 to 7) having the secondary recrystallization layer in the outermost layer exhibits some corrosion resistance even in the sprayed state by using a group IIIa element for the film forming material, and in particular, the coating is further subjected to electron beam irradiation. When the treatment was performed, the resistance was further improved, and it was found that the plasma corrosion damage amount was reduced by 10 to 30%.

TABLE 3

(Third Embodiment)

In this embodiment, the film was formed by the method of the second embodiment, and the plasma corrosion resistance of the formed film before and after the electron beam irradiation treatment was examined. As a test material, what formed the mixed oxide as shown directly next on the Al base material with the thickness of 200 micrometers by the atmospheric plasma spraying method was used.

(1) 95% Y ₂ O ₃ 5% Sc ₂ O ₃

(2) 90% Y ₂ O ₃ 10% Ce ₂ O ₃

(3) 90% Y ₂ O ₃ 10% Eu ₂ O ₃

In addition, the electron beam irradiation, the gas atmosphere component, the plasma spraying method, etc. after film-forming are the same as that of 2nd Example.

Table 4 combines the above results as plasma corrosion damage amount. As is apparent from the results shown in this table, the coating of the oxides in the group IIIa of the periodic table under conditions suitable for the present invention, even if such oxides are used in a mixed state, Al ₂ O ₃ (anode oxidation) of the comparative example shown in Table 3, Plasma corrosion resistance is better than B ₄ C film. In particular, when the film was subjected to electron beam irradiation, the performance was greatly improved, and it was found that excellent plasma corrosion resistance was exhibited.

TABLE 4

The technique of the present invention is used as a surface treatment technique of members and components used in general semiconductor processing apparatuses, as well as members and components used in plasma processing apparatuses that require more precise and advanced processing in recent years. . In particular, the present invention relates to a deposition shield, a baffle plate, a focus ring, and an upper surface of an apparatus for using an F-containing gas or a CH-containing gas, respectively, or a semiconductor processing apparatus for plasma processing in a harsh atmosphere using such gas repeatedly alternately. It is suitable as a surface treatment technique to members and components, such as a lower insulation, a shield ring, a bellows cover, an electrode, and a solid dielectric. Moreover, this invention is applicable as a surface treatment technique of the member for liquid crystal device manufacturing apparatuses.

Claims (15)

The ceramic coating member for semiconductor processing apparatuses which consists of a base material, the porous layer which consists of an oxide of group IIIa element of the periodic table coat | covered on the surface of this base material, and the secondary recrystallization layer of the said oxide provided on this porous layer. The ceramic coating member for semiconductor processing apparatuses of Claim 1 which has a lower coat between a base material and a porous layer. The method according to claim 1 or 2, wherein the base material comprises (a) aluminum and its alloys, titanium and its alloys, stainless steel, other special steels, Ni-based alloys, other metals or their alloys, (2) quartz, glass or oxides or carbides. , Borides, silicides, nitrides and ceramics composed of these mixtures, (3) cermets consisting of the ceramics and the above metals and alloys, (4) plastics, and (5) metal plating on the surfaces of the above materials (1) to (4). The ceramic coating member for semiconductor processing apparatuses characterized by forming one or a metal vapor deposition film. The method of claim 1 or 2, wherein the porous layer is Sc, Y or lanthanides (La, Ce, Pr, Nb, Pm, Sm, Eu, Gd, Tb, Dy, Ho, The ceramic coating member for semiconductor processing apparatuses characterized by consisting of layers of oxides of Er, Tm, Yb, and Lu. The ceramic coating member according to claim 1 or 2, wherein the porous layer is formed of a thermal spray coating having a porosity of about 5 to 20% having a layer thickness of about 50 to 2000 µm. The method of claim 1 or 2, wherein the secondary recrystallized layer is a high energy irradiation treatment layer formed by secondary transformation of the primary transformation oxide contained in the porous layer by a high energy irradiation treatment. Ceramic coating member for semiconductor processing equipment. 3. The secondary recrystallization layer is a layer having a porosity of less than 5% in which a porous layer containing tetragonal crystals is secondary transformed by a high energy irradiation treatment to form a tetragonal structure. Ceramic coating member for semiconductor processing apparatuses. The semiconductor processing according to claim 1 or 2, wherein the secondary recrystallized layer is a layer in which the primary transformed yttrium thermal spray coating composed of cubic crystal and monoclinic crystal is secondary transformed into cubic crystal by a high energy irradiation treatment. Ceramic cladding for the device. The ceramic coating member according to claim 1 or 2, wherein the secondary recrystallized layer has a maximum roughness Ry of about 6 to 16 µm. The ceramic cladding member for semiconductor processing apparatus according to claim 1 or 2, wherein the secondary recrystallized layer has an average roughness Ra of about 3 to 6 µm. The ceramic coating member according to claim 1 or 2, wherein the secondary recrystallized layer has a 10-point average roughness (Rz) of about 8 to 24 µm. The ceramic cladding member for semiconductor processing apparatus according to claim 1 or 2, wherein the secondary recrystallization layer has a layer thickness of about 100 µm or less. The said bottom coat is any 1 or more types of ceramics chosen from Ni, Al, W, Mo, Ti and their alloys, oxides, nitrides, borides, and carbides, The said metal, alloy And at least one selected from a cermet consisting of the ceramic, which is a film having a thickness of about 50 to 500 µm. The ceramic coating member for a semiconductor processing apparatus according to claim 6, wherein the high energy irradiation process is any one of electron beam irradiation and laser beam irradiation. The ceramic coating member for a semiconductor processing apparatus according to claim 7, wherein the high energy irradiation process is any one of electron beam irradiation and laser beam irradiation.

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