JP2007042672A - Plasma process device chamber member and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma process device chamber member in which plasma resistance is secured, which can be used for long time even if a cleaning processing is repeated and which is economically advantageous. <P>SOLUTION: The plasma process device chamber member is formed of an aluminum nitride sintered body whose porosity is 1% or less and whose torn face shows quality of transgranular fracture. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a chamber member for a plasma processing apparatus and a method for manufacturing the same.

Semiconductor manufacturing processes include various plasma processes such as a CVD process, an etching process, and a resist removal process. As a chamber member for a plasma processing apparatus, aluminum nitride having high plasma resistance is often used by being used in a plasma environment.
Conventionally, a sintering method of an aluminum nitride sintered body is generally a method in which a sintering aid such as Y ₂ O ₃ is added. For example, the sintered body is densified using a hot press sintering method or the like. Thus, aluminum nitride with improved plasma resistance has been manufactured (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 2002-3277

In recent semiconductor processes, the process temperature in the plasma process tends to increase due to miniaturization of design rules. Further, improvement of throughput is an important issue for the purpose of cost reduction.
For example, also in a plasma CVD apparatus, the process temperature rises, and the processing time tends to be shortened in order to improve the throughput. Accordingly, the difference between the process temperature and the cooling temperature for removing the wafer is increased, and the repeated temperature cycle tends to be short, and the thermal shock to the chamber member has become severe.
Further, when the chamber member is actually used, a deposition film is deposited not only on the wafer surface but also on the chamber member due to the process gas.

In a conventional chamber member made of an aluminum nitride sintered body, a deposition film deposited on the surface thereof is generally used by flowing a gas such as NF _{3 and} periodically cleaning it with fluorine plasma or the like. Therefore, plasma resistance (fluorine plasma resistance or the like) is required so that the chamber member is not damaged by the cleaning process.

Moreover, in such a chamber member, for example, when Y ₂ O ₃ is used as a sintering aid, Y ₂ O ₃ , Y ₂ O ₃ compounds, etc. are present at the grain boundaries, and aluminum nitride and Y 2 Due to the difference in thermal expansion from ₂ O ₃ and Y ₂ O ₃ compounds, peeling of the deposition film occurs due to thermal stress generated during the process, which causes generation of particles on the wafer surface and the like during the process. There was a thing.
Therefore, there is a demand for a member that maintains plasma resistance and can reduce the peeling of the deposition film due to thermal shock.

The present invention has been made in view of the above-mentioned problems, and has a plasma resistance, a chamber member for a plasma processing apparatus that is economically advantageous and can be used for a long time even after repeated cleaning treatments, and its manufacture. And to provide a method.
It is another object of the present invention to provide a chamber member capable of reducing the amount of particles without causing the deposition film to peel off even when the thermal shock during the plasma process increases.

The chamber member for a plasma processing apparatus of the present invention is characterized by comprising an aluminum nitride sintered body having a porosity of 1% or less and a fracture surface exhibiting the property of intragranular fracture.
In the chamber member for a plasma processing apparatus, the aluminum nitride sintered body preferably does not contain a rare earth element, or the rare earth element content is 0.4% by weight or less.

Further, in the method for producing a chamber member for a plasma processing apparatus of the present invention, after forming a molded body by molding a mixture containing an aluminum nitride raw material powder having a particle size distribution of D50 of 2 μm or less and D90 of 5 μm or less, The molded body is sintered at normal pressure while performing vacuum replacement stepwise.

The chamber member for a plasma processing apparatus of the present invention is composed of an aluminum nitride sintered body having a porosity of 1% or less and a fracture surface exhibiting the property of intragranular fracture. Excellent characteristics, plasma resistance is secured, and can be used for a long time.
The aluminum nitride sintered body does not contain a rare earth element, or the rare earth element content is 0.4% by weight or less, and the amount of foreign matter present at the grain boundary is small. When the chamber member is used in a plasma CVD apparatus, the generation of particles due to the peeling of the deposition film in the plasma process can be suppressed.

In addition, the method for manufacturing a chamber member for a plasma processing apparatus according to the present invention comprises forming an aluminum nitride raw material powder having a particle size distribution D50 of 2 μm or less and a D90 of 5 μm or less, followed by firing under the special conditions described above. Therefore, it is possible to produce an aluminum nitride sintered body in which the particles constituting the sintered body are relatively uniform and firmly bonded, have plasma resistance, and do not generate particles.

The chamber member for a plasma processing apparatus of the present invention is characterized by comprising an aluminum nitride sintered body having a porosity of 1% or less and a fracture surface exhibiting the property of intragranular fracture.
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings together with a plasma process apparatus provided with a chamber member for a plasma process apparatus of the present invention.

FIG. 1 is a cross-sectional view schematically showing a plasma CVD apparatus using a chamber member for a plasma processing apparatus of the present invention.
2A is a front view showing an example of a chamber member for a plasma processing apparatus of the present invention, FIG. 2B is a longitudinal sectional view of the chamber member shown in FIG. 2A, and FIG. It is a bottom view of the chamber member shown to a).
FIG. 3A is a front view showing another example of the chamber member for a plasma processing apparatus of the present invention, and FIG. 3B is a cross-sectional view of the chamber member shown in FIG.

As shown in FIG. 1, a plasma CVD apparatus 10 has a processing object 30 such as a silicon wafer placed in a cylindrical vacuum chamber 12 whose upper and lower surfaces are circular, and the processing object is formed by a built-in heater 14. A disk-shaped substrate holder 16 for heating 30, a shower type gas ejection head 18 for ejecting a reactive gas (reactive gas) from the ceiling surface of the vacuum chamber 12 into the chamber, and a similar reactive gas on the inner periphery And a nozzle-type gas ejection head 22 for ejecting from the surface into the chamber. Here, the shower type gas ejection head 18 is attached to the approximate center of the ceiling surface, and a number of nozzle type gas ejection heads 22 are attached along the circumference on the inner peripheral surface. In addition, the vacuum chamber 12 includes a vacuum pump 26 for bringing the inside of the chamber into a substantially vacuum state, and a pair of electrodes (not shown) to which a high-frequency voltage is applied.
In the plasma CVD apparatus 10, the shower type gas ejection head 18 and the nozzle type gas ejection head 22 are both examples of the chamber member for the plasma processing apparatus of the present invention.

Next, the shower type gas ejection head 18 which is an example of the chamber member for the plasma processing apparatus of the present invention shown in FIGS.
The shower-type gas ejection head 18 is formed in a substantially truncated cone shape, has one reaction gas inlet 18a at the center of the upper surface thereof, and has a total of five reaction gas outlets at the center of the lower surface and positions equidistant from the center. 18b. Inside the shower type gas ejection head 18, there are formed gas passages 18c branched from the reaction gas inlet 18a to reach a plurality of reaction gas outlets 18b. The shower type gas ejection head 18 is made of an aluminum nitride sintered body having a porosity of 1% or less and a fractured surface exhibiting intragranular fracture properties.

Next, the nozzle type gas ejection head 22 which is an example of the chamber member for the plasma processing apparatus of the present invention shown in FIGS. 3A and 3B will be described.
The nozzle-type gas ejection head 22 is formed in a substantially cylindrical shape, and has one reactive gas inlet 22a at the center of its base end face and one reactive gas outlet 22b at the center of its distal end face. Inside the nozzle type gas ejection head 22, there is formed a gas passage 22c that does not branch from the reaction gas inlet 22a and extends straight to the reaction gas outlet 22b. Similarly to the shower type gas ejection head 18, the nozzle type gas ejection head 22 is made of an aluminum nitride sintered body having a porosity of 1% or less and a fracture surface exhibiting intragranular fracture properties.

Next, the operation of the plasma CVD apparatus 10, that is, the operation of forming a film on the surface of the object 30 to be processed such as a silicon wafer will be briefly described. First, an unillustrated transporter is operated to place an unprocessed object 30 carried into the vacuum chamber 12 on the upper surface of the substrate holder 16. Subsequently, the inside of the chamber is adjusted to a predetermined degree of vacuum by the vacuum pump 26, and the built-in heater 14 of the substrate holder 16 is energized to heat the object 30 to be processed. Subsequently, a reaction gas is introduced at a predetermined flow rate into a reaction gas inlet 18a of the shower type gas ejection head 18 and a reaction gas inlet 22a of each nozzle type gas ejection head 22 by a mass flow controller (not shown), and a high frequency is generated between a pair of electrodes (not shown). Apply voltage. Then, the reaction gas ejected into the vacuum chamber 12 from each reaction gas outlet 18b of the shower type gas ejection head 18 or from the reaction gas outlet 22b of each nozzle type gas ejection head 22 is glow discharge generated between a pair of electrodes (not shown). Is decomposed and excited by the plasma to be in a plasma state, and gas molecules are deposited on the surface of the object 30 to form a thin film.

The chamber member for a plasma process apparatus of the present invention such as the shower type gas jet head 18 and the nozzle type gas jet head 22 described above has an aluminum nitride having a porosity of 1% or less and a fracture surface exhibiting the property of intragranular fracture. It consists of a sintered body.
When the porosity exceeds 1%, it becomes difficult to obtain an aluminum nitride sintered body in which the fracture surface exhibits the property of intragranular fracture.

Moreover, in the aluminum nitride sintered body in which the fracture surface exhibits the property of intragranular fracture, degranulation at the grain boundary is reduced, and plasma resistance can be ensured. In other words, when the fractured surface exhibits the property of grain boundary fracture, in the cleaning process using fluorine plasma, degranulation at the grain boundary is likely to occur, resulting in insufficient plasma resistance.
In the present specification, that the fracture surface exhibits the property of intragranular fracture means that 5% or more of the fracture surface is in a state in which fracture progresses within the crystal grain. On the other hand, when the fracture progress within the fracture surface is less than 5% and most of the fracture progresses along the grain boundary, the fracture surface exhibits the property of grain boundary fracture.
Further, the properties of the fracture surface can be determined by microscopic observation using SEM or the like.

The aluminum nitride sintered body preferably does not contain a rare earth element or the rare earth element content is 0.4 wt% or less.
In this case, generation of thermal stress due to thermal shock at the grain boundary is reduced. For example, when used in a plasma CVD apparatus, the deposition film hardly peels off due to the thermal stress, and the deposition film It is possible to reduce the generation of particles due to peeling.

Examples of the rare earth element contained in the aluminum nitride sintered body include those derived from a sintering aid blended in the raw material mixture, and specific examples of the sintering aid include, for example, cerium compounds and scandium. Examples thereof include yttrium compounds such as compounds and Y ₂ O ₃ .
In the present specification, the rare earth element content contained in the aluminum nitride sintered body means the rare earth element content in the rare earth compound contained in the aluminum nitride sintered body, and the rare earth element contained in the aluminum nitride. The total amount of Of course, the above-mentioned aluminum nitride sintered body does not necessarily contain a rare earth compound or a rare earth element.

On the other hand, when the chamber member for a plasma processing apparatus of the present invention is used in a plasma CVD apparatus, if the rare earth element content exceeds 0.4 wt%, for example, Y ₂ O ₃ or Y ₂ O ₃ compound Are present at the grain boundaries, and due to the difference in thermal expansion that occurs between different materials of these and aluminum nitride, the aluminum nitride sintered body is deformed during the plasma process, which causes thermal stress on the deposition film. This is because, due to this thermal stress, the deposition film is peeled off and particles are generated.
The rare earth element content is preferably as small as possible from the viewpoint of particle generation.

Further, the plasma processing apparatus chamber member of the present invention has been described so far as being used in an apparatus for performing a plasma CVD process. Is not limited to a plasma CVD apparatus, but can also be used for an apparatus that performs a plasma etching process or a plasma ashing process.

In addition, when the chamber member for a plasma processing apparatus of the present invention is used in an apparatus for performing a plasma CVD process, it is desirable that the plasma process is resistant and that particles caused by peeling of the deposition film do not occur in the plasma process. As described above, when used in an apparatus for performing a plasma etching process or a plasma ashing process, since no deposition film is formed, the presence or absence of generation of particles is not a problem, and plasma resistance is provided. This is very important.

Next, the manufacturing method of the chamber member for plasma processing apparatuses of this invention is demonstrated.
In the method for manufacturing a chamber member for a plasma processing apparatus according to the present invention, a molded body is produced by molding a mixture containing aluminum nitride raw material powder having a particle size distribution of D50 of 2 μm or less and D90 of 5 μm or less. The body is sintered at normal pressure while performing vacuum replacement step by step.
Hereinafter, the manufacturing method of the chamber member for plasma processing apparatus of this invention is demonstrated in order of a process.

(1) First, an aluminum nitride raw material powder having a particle size distribution D50 of 2 μm or less and a D90 of 5 μm or less is mixed with a binder or a solvent, if necessary, to obtain an aluminum nitride raw material powder. A mixture containing is prepared.
By setting the particle size distribution of the aluminum nitride raw material powder within the above range, all particles are covered with a liquid phase during sintering, the rearrangement of particles is facilitated, the contact angle is reduced, and the grain growth proceeds uniformly. Therefore, a sintered body in which the porosity is 1% or less, the fracture surface exhibits the property of intragranular fracture, and the particles are firmly bonded to each other even if no sintering aid is added. Can be obtained.
On the other hand, when D50 of the particle size distribution exceeds 2 μm or D90 exceeds 5 μm, grain growth is inhibited during sintering, and the obtained aluminum nitride sintered body has reduced plasma resistance. Become.
The particle size distribution D50 is desirably 1 μm or less. This is because less particles are generated in the manufactured chamber member for the plasma processing apparatus.

The binder is not particularly limited, and examples thereof include acrylic binders, ethyl cellulose, butyl cellosolve, and polyvinyl alcohol. These may be used alone or in combination of two or more.
The solvent is not particularly limited, and examples thereof include alcohols having 1 to 6 carbon atoms such as methanol, ethanol, propanol, butanol, pentanol, and hexanol, α-terpineol, glycol, and the like. These may be used alone or in combination of two or more.

The aforementioned mixture, if necessary, a cerium compound, scandium compound may be mixed with a sintering aid composed of rare earth compounds of yttrium compounds such as Y ₂ O _3.
However, when the sintering aid is blended, the blending amount is desirably set so that the rare earth element content is 0.4% by weight or less in the sintered aluminum nitride sintered body.
The reason why the amount of the rare earth element in the aluminum nitride sintered body is desirably 0.4% by weight or less is as already described.

(2) Next, the mixture is formed into a predetermined shape to produce a generated shape, and then the raw formed body is degreased as necessary.
Although it does not specifically limit as a concrete formation method, For example, it shape | molds by the CIP shaping | molding method to the predetermined | prescribed external appearance shape, and after that, the method of opening the hole equivalent to a gas passage, the injection molding method, and the casting molding method, The method etc. which shape | mold to a desired shape can be used.

(3) Next, the molded body is sintered at normal pressure while performing vacuum replacement stepwise to complete a chamber member for a plasma process apparatus.
Specifically, for example, during firing in a nitrogen gas atmosphere, the nitrogen gas is stopped once at 1500 ° C., and the inside of the furnace is evacuated for 1 hour, and then the nitrogen gas is purged to return to the original nitrogen atmosphere. Then raise the temperature. Furthermore, the same operation is carried out in three steps of 1600 ° C., 1700 ° C. and 1800 ° C. (four steps in combination with the operation at 1500 ° C.), then the temperature is raised to 1860 ° C. and kept at this temperature for 6 hours. A method for completing the sintering can be used.
By using such a method, it is possible to remove a gas (for example, O ₂ gas) that inhibits the sintering generated during firing, and as a result, the resulting aluminum nitride sintered body is densified.

Moreover, in the method mentioned above, although the calcination temperature is switched 100 degreeC at a time, this calcination temperature should just switch about 50-200 degreeC normally.
Moreover, the temperature difference of each step is not necessarily the same.
In the manufacturing method described above, the initial temperature maintained while performing vacuum replacement is 1500 ° C., but this temperature is not limited to 1500 ° C., and may be any temperature above the firing temperature of aluminum nitride. Good.

Moreover, in the method mentioned above, except for the last firing temperature, each firing temperature is switched for 1 hour, but the holding time at each firing temperature other than the last firing temperature is usually about 30 minutes to 2 hours. If it is.
Further, the holding time of each stage is not necessarily the same.

In the above-described method, vacuum replacement is performed in four stages. However, the manufacturing method of the present invention is not particularly limited as long as it is two or more stages.
It should be noted that a larger number of stages is desirable in that a denser sintered body can be produced.

In the production method of the present invention, after the completion of sintering, smoothing treatment by grinding and polishing or chemical etching may be performed as necessary, but such treatment is usually unnecessary.
In the method for producing a chamber member for a plasma processing apparatus according to the present invention through such steps, the above-described chamber member for a plasma processing apparatus of the present invention can be suitably produced.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1
Granules are obtained by mixing 4 parts by weight of an acrylic binder and 53 parts by weight of alcohol consisting of butanol and ethanol with 100 parts by weight of aluminum nitride powder (Tokuyama, D50: 1.5 μm, D90: 4.2 μm). It was.
Next, the formed granule was formed into a substantially cylindrical shape by a CIP molding method, a hole corresponding to the gas passage was formed, and processed into a nozzle type gas ejection head (see FIG. 3).

Next, degreasing was performed under conditions of an oxidizing atmosphere and 600 ° C. for 5 hours.
Thereafter, firing was performed in a nitrogen gas atmosphere. In the middle, the nitrogen gas was stopped once at 1500 ° C., and the inside of the furnace was evacuated for 1 hour, and then the temperature was raised after purging the nitrogen gas to return to the original nitrogen gas atmosphere. Further, the same operation was performed in three stages of 1600 ° C., 1700 ° C. and 1800 ° C. Next, the temperature was raised to 1860 ° C., and baking was performed for 6 hours under the conditions of keeping, thereby producing a nozzle type gas ejection head.
In this example, no smoothing treatment or chemical etching by grinding and polishing was performed after sintering.

(Examples 2 and 3)
A nozzle type gas ejection head was manufactured in the same manner as in Example 1 except that the aluminum nitride powder was replaced with one having the particle size distribution shown in Table 1.

Example 4
To 99.9 parts by weight of aluminum nitride powder (Tokuyama, D50: 1.2 μm, D90: 4.0 μm) and 0.1 part by weight of Y ₂ O ₃ (Japan Yttrium, D50: 0.4 μm), A nozzle-type gas ejection head was manufactured in the same manner as in Example 1 except that 4 parts by weight of an acrylic binder and 53 parts by weight of alcohol composed of butanol and ethanol were mixed to obtain granules.
In the nozzle type gas ejection head manufactured in this example, the Y element content is 0.08% by weight.

(Example 5)
To 99.7 parts by weight of aluminum nitride powder (Tokuyama, D50: 1.7 μm, D90: 4.5 μm) and 0.3 part by weight of Y ₂ O ₃ (Japan Yttrium, D50: 0.4 μm), A nozzle-type gas ejection head was manufactured in the same manner as in Example 1 except that 4 parts by weight of an acrylic binder and 53 parts by weight of alcohol composed of butanol and ethanol were mixed to obtain granules.
In the nozzle type gas ejection head manufactured in this example, the Y element content is 0.24% by weight.

(Example 6)
To 99.5 parts by weight of aluminum nitride powder (Tokuyama, D50: 1.8 μm, D90: 4.7 μm) and 0.5 part by weight of Y ₂ O ₃ (Nihon Yttrium, D50: 0.4 μm), A nozzle-type gas ejection head was manufactured in the same manner as in Example 1 except that 4 parts by weight of an acrylic binder and 53 parts by weight of alcohol composed of butanol and ethanol were mixed to obtain granules.
In the nozzle type gas ejection head manufactured in this example, the Y element content is 0.39% by weight.

(Example 7)
To 100 parts by weight of aluminum nitride powder (Tokuyama, D50: 1.7 μm, D90: 4.4 μm), 4 parts by weight of an acrylic binder and 53 parts by weight of alcohol composed of butanol and ethanol are mixed to obtain granules. It was.
Next, the granules formed in the same manner as in Example 1 were processed into the shape of a nozzle type gas ejection head.

Next, degreasing was performed under conditions of an oxidizing atmosphere and 600 ° C. for 5 hours.
Thereafter, firing was performed in a nitrogen gas atmosphere. In the middle, the nitrogen gas was stopped once at 1500 ° C., and the inside of the furnace was evacuated for 30 minutes. Thereafter, the nitrogen gas was purged to return to the original nitrogen gas atmosphere, and then the temperature was raised. Further, the same operation was performed at 1700 ° C. (vacuum replacement was performed in two stages in combination with 1500 ° C.). Next, the temperature was raised to 1860 ° C., and baking was performed for 6 hours under the conditions of keeping, thereby producing a nozzle type gas ejection head.
In this example as well, smoothing treatment and chemical etching by grinding and polishing were not performed after sintering.

(Reference Example 1)
Acrylic binder 4 with respect to 99 parts by weight of aluminum nitride powder (Tokuyama, D50: 1.5 μm, D90: 4.2 μm) and 1 part by weight of Y ₂ O ₃ (Japan Yttrium, D50: 0.4 μm) A nozzle-type gas ejection head was manufactured in the same manner as in Example 1 except that 53 parts by weight of alcohol composed of parts by weight of butanol and ethanol were mixed to obtain granules.
In the nozzle type gas ejection head manufactured in this reference example, the content of the Y element is 0.79% by weight.

(Reference Example 2)
Acrylic binder 4 with respect to 98 parts by weight of aluminum nitride powder (Tokuyama, D50: 1.5 μm, D90: 4.2 μm) and ₂ parts by weight of Y ₂ O ₃ (made by Japan Yttrium, D50: 0.4 μm) A nozzle-type gas ejection head was manufactured in the same manner as in Example 1 except that 53 parts by weight of alcohol composed of parts by weight of butanol and ethanol were mixed to obtain granules.
In the nozzle type gas ejection head manufactured in this reference example, the Y element content is 1.57% by weight.

(Comparative Examples 1 and 2)
A nozzle type gas ejection head was manufactured in the same manner as in Example 1 except that the aluminum nitride powder was replaced with one having the particle size distribution shown in Table 1.

The manufactured nozzle type gas ejection head was measured for porosity and particle generation amount, evaluated for plasma resistance, and observed for fractured surfaces by the following methods.

(1) Measurement of porosity The porosity was measured according to "Measurement method of sintered density and open porosity of fine ceramics" of JIS R 1634.
The results are shown in Table 2.

(2) Measurement of particle generation amount Attached in a chamber of a plasma apparatus, monosilane (SiH ₄ ) is flowed as a process gas into the chamber continuously for 1 hour to generate silane plasma, and a silica film is applied to the nozzle type gas ejection head. Deposited.
Next, with the nozzle-type gas ejection head attached, 100 cycles of a cooling cycle in which the temperature was raised from room temperature to 800 ° C. in 2 minutes, kept at 800 ° C. for 1 minute, and lowered to room temperature in 5 minutes was continuously performed.
Next, a wafer having a diameter of 300 mm was placed in the chamber, and silane plasma was generated by monosilane (SiH ₄ ) to actually form a film, and then the amount of particles on the wafer was measured with a particle counter. The results are shown in Table 2.
In general, if the amount of particles is 50 or less, it can be said that the product is a desirable numerical value.

(3) Evaluation of plasma resistance After completion of the measurement in (2) above, with the nozzle type gas ejection head attached, NF ₃ was flowed into the chamber to generate fluorine plasma, and the surface of the nozzle type gas ejection head was measured. The silica film was removed.
Thereafter, the nozzle type gas ejection head was taken out from the chamber, and it was confirmed that the silica film was completely removed, and the weight of the nozzle type gas ejection head was measured.
Further, a nozzle type gas ejection head was attached again in the chamber, and NF ₃ was flowed into the chamber to generate fluorine plasma. In this state, the nozzle type gas ejection head was exposed to continuous fluorine plasma for 3 hours.
Then, the nozzle type gas ejection head was taken out again, the weight was measured, and the weight change rate was calculated. The results are shown in Table 2.
Here, the plasma resistance of the nozzle type gas ejection head is evaluated based on the weight change rate, and it can be said that the smaller the weight change rate, the higher the plasma resistance.

(4) Observation of fracture surface The nozzle type gas ejection head was destroyed, and the fracture state of the fracture surface was observed with SEM (manufactured by JEOL Ltd.). The results are shown in Table 2. The criteria for determining intragranular fracture and intergranular fracture are as described above.
In addition, the SEM photograph of the torn surface of the nozzle type gas ejection head which concerns on Example 1 and Comparative Example 1 is shown to FIG.

As is apparent from the results shown in Table 2, the chamber member (nozzle-type gas ejection head) for the plasma processing apparatus according to the example has a porosity of as small as 1% or less, and the fracture surface has a property of intragranular fracture at the time of fracture. The amount of particles was as small as 50 or less, and the weight reduction rate was 0.15% or less, and the plasma resistance was ensured.
In particular, in the plasma processing apparatus chamber members according to Examples 1 to 3 and 7, the amount of particles is as small as 30 or less. This is presumably because the rare earth element is not contained in the aluminum nitride sintered body.

On the other hand, in the plasma processing apparatus chamber members according to Reference Examples 1 and 2, although the weight reduction rate was 0.12% or less and the plasma resistance was ensured, the generation amount of particles was large. . This is presumably because the amount of rare earth elements contained in the aluminum nitride sintered body is large.
Therefore, the plasma processing apparatus chamber members according to Reference Examples 1 and 2 are not very suitable for use in the plasma CVD process, but can be suitably used in the plasma etching process and the plasma ashing process.

Further, in the plasma processing apparatus chamber members according to Comparative Examples 1 and 2, the amount of particles generated was similar to that of the plasma processing apparatus chamber member according to the example, but the weight reduction rate was 0.6%. It was a large value exceeding, and the plasma resistance was insufficient, and it was not suitable for long-term use.

It is sectional drawing which shows typically the plasma CVD apparatus using the chamber member for plasma process apparatuses of this invention. (A) is a front view which shows an example of the chamber member for plasma processing apparatuses of this invention, (b) is a longitudinal cross-sectional view of the chamber member shown to (a), (c) is (a). It is a bottom view of the chamber member shown in FIG. (A) is a front view which shows another example of the chamber member for plasma processing apparatuses of this invention, (b) is sectional drawing of the chamber member shown to (a). 2 is a SEM photograph of a fracture surface of a nozzle-type gas ejection head according to Example 1. 4 is a SEM photograph of a fracture surface of a nozzle type gas ejection head according to Comparative Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Plasma CVD apparatus 12 Vacuum chamber 14 Built-in heater 16 Substrate holder 18 Shower type gas ejection head 18a Reaction gas inlet 18b Reaction gas outlet 18c Gas passage 22 Nozzle type gas ejection head 22a Reaction gas inlet 22b Reaction gas outlet 22c Gas passage 26 Vacuum pump 30 workpiece

Claims (3)

A chamber member for a plasma process apparatus, comprising a sintered aluminum nitride having a porosity of 1% or less and a fracture surface exhibiting the property of intragranular fracture. The chamber member for a plasma processing apparatus according to claim 1, wherein the aluminum nitride sintered body does not contain a rare earth element or the rare earth element content is 0.4 wt% or less. After forming a molded body by molding a mixture containing aluminum nitride raw material powder having a particle size distribution of D50 of 2 μm or less and D90 of 5 μm or less, the molded product is brought to normal pressure while performing vacuum substitution step by step. A method of manufacturing a chamber member for a plasma processing apparatus, characterized in that sintering is performed.