KR102352039B1 - Manufacturing Method Edge Ring of Electrostatic Chuck and Electrostatic Chuck Comprising Same - Google Patents

Abstract

According to a method for manufacturing an edge ring of the present invention, after a ceramic powder is charged into a ring-shaped molding mold using a hot press method, a ring-shaped edge ring with a large diameter or a small diameter according to an outer diameter of a wafer can be manufactured easily and readily while being inexpensive since it is manufactured by pressure sintering. The method for manufacturing the edge ring comprises: a step of inserting; a step of moving; a step of manufacturing a first sintered body; a step of burying; and a step of manufacturing an edge ring.

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing an edge ring of an electrostatic chuck and an electrostatic chuck including an edge ring manufactured therefrom.

The present invention relates to a method for manufacturing an edge ring of an electrostatic chuck and an electrostatic chuck including an edge ring manufactured therefrom.

There exist plasma processing apparatuses, such as a plasma etching apparatus, a plasma CVD apparatus, and a plasma ashing apparatus. Such a plasma processing apparatus is usually equipped with a wafer placement apparatus for placing a wafer in a vacuum chamber. The wafer placement apparatus includes an electrostatic chuck for adsorbing and fixing a wafer subjected to plasma processing to a wafer placement surface, and a cooling plate for cooling the electrostatic chuck. do.

The plasma processing apparatus applies a DC voltage to the internal electrodes in a state where the wafer is placed on the wafer placement surface to generate an electrostatic force (Coulomb force or Johnson-Rahbek force), thereby adsorbing and fixing the wafer to the wafer placement surface. And in this state, plasma is generated so as to be in contact with the wafer. In this case, an edge ring or a focus ring may be provided on the outer periphery of the wafer placement surface in order to stably generate plasma up to the edge of the wafer and to protect the surface of the electrostatic chuck from plasma.

In general, the edge ring cuts the ingot in a circular plate shape, cuts out the disc member, and cuts out a central portion of the disc member, thereby producing a ring-shaped edge ring. In recent years, a large diameter of a plasma processing apparatus is gradually required, and a large diameter edge ring is required.

However, in order to manufacture an edge ring suitable for a large-diameter electrostatic chuck, it is necessary to manufacture an ingot having a large outer diameter. A number of problems occurred such as excessively high manufacturing cost of the in-edge ring, difficulty in controlling the thickness of the edge ring, and poor plasma process yield.

In order to solve the above problem, Japanese Patent Application Laid-Open No. 10-2011-003730 proposes a manufacturing method in which the edge ring is divided into a plurality and the arc-shaped member is connected in the circumferential direction to assemble in a ring shape, but the contact between the arc-shaped members A gap is formed on the mating surface, and as the adhesive is exposed to the outside and decomposed, gas is released, there is a problem that abnormal discharge (arcing) occurs, the thermal conductivity becomes non-uniform, and the circumferential direction in the plasma processing device As a result, the plasma environment becomes non-uniform, and various problems occur, such as making it difficult to uniformly process the wafer for plasma processing.

In order to solve the above problem, Korean Patent Application Laid-Open No. 10-2009-0101129 proposes a structure including a dielectric between the susceptor and the edge ring, but the structure is complicated, making it impossible to manufacture a large diameter, and the dielectric and There is a problem that precise design between the edge rings is difficult.

Patent Document 1. Japanese Patent Laid-Open No. 10-2011-003730 Patent Document 2. Korean Patent Publication No. 10-2009-0101129

The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide a method for manufacturing an edge ring capable of manufacturing a ring-shaped edge ring flat on a cross-section, rather than manufacturing an ingot or a divided structure. .

In order to achieve the above object, the present invention comprises the steps of: a) charging and molding ceramic powder into a ring-shaped molding mold; b) primary pressure sintering of the compact; c) inserting and seating an electrode on the lower surface of the primary sintered body; d) manufacturing an edge ring by secondary pressure sintering of the first sintered body on which the electrode is seated; provides a method of manufacturing an edge ring comprising.

The ceramic powder may include 94.6 to 98.6 wt% of Al ₂ O ₃ , ₁ to 5 wt% of ZrO ₂ and 0.05 to 0.5 wt% of MgO.

Steps b) and d) may be performed by a hot press method.

Step b) may be performed under an inert gas, at a temperature of 1000 to 1700 °C, and under a pressure of 10 to 50 MP.

Step d) may be performed under an inert gas at a temperature of 1000 to 1700 °C and a pressure of 10 to 50 MPa.

After step d), e) a quenching step of rapidly cooling the edge ring prepared in step d); may further include.

According to the edge ring manufacturing method of the present invention, since ceramic powder is charged into a ring-shaped molding mold using a hot press method and then pressure sintered to manufacture, the ring-shaped edge ring has a large diameter or a small diameter according to the outer diameter of the wafer. can be manufactured inexpensively and easily. In particular, the edge ring manufactured by the method according to the present invention is capable of more precise control of thickness and density than an edge ring manufactured using a dividing member or an ingot, is strong against thermal shock, and maintains a uniform plasma environment during plasma treatment Therefore, the plasma process yield can be maintained high for a long period of time.

1A and 1B are flowcharts schematically illustrating an edge ring manufacturing process of the present invention.
2 is a cross-sectional view of a hot press sintering apparatus according to a preferred embodiment of the present invention.
3 is a cross-sectional view of the forming mold 60 shown in FIG.
4 is a photograph taken of the edge ring prepared in Example 2 of the present invention.
Figure 5 is a microstructure photograph of the central portion of the edge ring prepared in Example 2 of the present invention, 5c, e is an enlarged photograph of 5b, d.
6 is a microstructure photograph of a portion in which an electrode is embedded in the edge ring manufactured in Example 2 of the present invention, and 6c is an enlarged photograph of 6b.
7 is a microstructure photograph of the right part in which the electrode is embedded in the edge ring manufactured in Example 2 of the present invention, 7c is an enlarged photograph of 7b.
8 is a photograph of measuring the thermal distribution of an electrostatic chuck having an edge ring manufactured in Example 2 of the present invention.
9 is a photograph of an external appearance of an electrostatic chuck having an edge ring manufactured in Example 2 of the present invention.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method for manufacturing an edge ring comprising the following steps.

a) injecting the ceramic powder into a ring-shaped molding mold;

b) loading the molding mold into a chamber of a hot press sintering apparatus, performing primary pressure sintering;

c) embedding an electrode in the upper surface of the primary sintered body; and

d) Secondary pressure sintering of the first sintered body on which the electrode is seated by a hot press to manufacture an edge ring.

1A and 1B are flowcharts schematically illustrating a series of manufacturing processes in order to explain the edge ring manufacturing process of the present invention.

Referring to FIG. 1 , in order to manufacture an edge ring according to the present invention, ceramic powder is first put into a ring-shaped molding mold (step a).

Here, the ceramic powder is not particularly limited as long as it is a ceramic material that can be appropriately selected according to the material and purpose of use of the electrostatic chuck, but is preferably Al ₂ O ₃ , Y ₂ O ₃ , Al ₂ O ₃ /Y ₂ O ₃ , ZrO ₂ , Autoclaved lightweight concrete (AlC), TiN, AlN, TiC, MgO, CaO, CeO ₂ , TiO ₂ , BxCy, BN, SiO ₂ , SiC, YAG, Mullite, AlF ₃ and mixtures thereof and more preferably 90 to 98.6 wt% Al ₂ O ₃ , 0.1 to 6 wt% ZrO _{2 ,} and 0.01 to 5 wt% MgO, even more preferably 94.6 to 98.6 wt% weight % Al ₂ O ₃ , 1 to 5 weight % ZrO ₂ and 0.05 to 0.5 weight % MgO, most preferably 96.4 weight % Al ₂ O ₃ , 3.5 weight % ZrO ₂ and 0.1% by weight of MgO.

The particle size of the ceramic powder may be 10 to 1000 nm, preferably 40 to 500 nm. If the particle size of the nanopowder is less than 40 nm, it is difficult to prepare a slurry, and if it exceeds 500 nm, it is not mixed properly. It is undesirable because it may adversely affect the edge ring.

The ceramic powder may further include a surfactant, and the amount of the surfactant is preferably 0.1 to 5.0% by weight based on the total weight of the ceramic powder. Since the manufacturing method of the present invention uses a ring-shaped molding mold, it is possible to manufacture a high-density edge ring with a significantly smaller amount of surfactant than for manufacturing an ingot. This has the advantage that the degreasing fixing time can be significantly reduced or omitted.

If the surfactant is less than 0.1% by weight, the ceramic powder is not properly mixed in a small amount, and if it exceeds 5.0% by weight, the effect increase due to excessive content is not large, and it is not preferable because it may adversely affect the manufactured edge ring.

The surfactant is preferably one or more selected from the group consisting of binders, lubricants, plasticizers and dispersants, but is not limited thereto.

The molding mold is a metal mold pre-formed in a ring shape, which is a shape to be molded to form the ceramic powder in a ring shape. However, it may be a molding mold serving as a frame for provisionally molding a ring-shaped molded body by pressure such as hydraulic press molding after the ceramic powder is added.

The molding mold may be appropriately selected depending on the process, and is not particularly limited as long as it is a material commonly used in the art. For example, in the case of manufacturing a molded body, it is not particularly limited as long as it is made of a metal, and when the molding mold is directly charged into a hot press and sintered under pressure, a material such as graphite that can withstand high temperatures may be used.

The molding mold may be provided directly in the chamber of the hot press sintering apparatus in a state divided into a plurality of molds such as the upper mold and the lower mold (steps a and b), and at this time, to have a ring shape through pressing force and high temperature sintering It can be molded and sintered.

In a state in which the ceramic powder is inserted into the forming mold, it may be carried in or out of the chamber of the hot press sintering apparatus.

In the method for manufacturing an edge ring according to the present invention, between steps a) and b), a-1) presses the molding mold prepared in step a) to prepare a molded body, and this is molded into a ring shape for hot press The step of transferring to the mold; may further include (Fig. 1b). By temporarily pressing the molding mold prepared in step a) through step a-1), the strength of the finally produced edge ring can be improved and processing can be facilitated.

In addition, when step a-1) is further included in the manufacturing method of the edge ring, it is preferable to use a molding mold made of a metal material for the molding mold of step a).

At this time, the molding mold is not particularly limited as long as it is made of metal as described above. In addition, the ring-shaped forming mold for hot press is a mold that can be carried in or taken out directly into the chamber of the hot press sintering apparatus, and may preferably be made of graphite.

In the edge ring manufacturing method according to the present invention, after step a), the method may further include a degreasing step of removing the surfactant from the ceramic powder while being put into the molding mold before step b).

Step b) is a step of primary pressure sintering by loading the molding mold into the chamber of the hot press sintering apparatus, wherein the molding mold is loaded into the chamber of the hot press sintering apparatus in a state in which the ceramic powder is inserted.

The hot press sintering apparatus is not particularly limited as long as it is a conventional hot press sintering apparatus, and can be used, but may be the hot press sintering apparatus of FIG. 2 as a preferred embodiment.

2 is a cross-sectional view of a hot press sintering apparatus according to a preferred embodiment of the present invention, and FIG. 3 is a cross-sectional view of the forming mold 60 shown in FIG.

As shown in FIG. 2, in the hot press sintering apparatus 10 of the present invention, a mold member 20, a heating member 40, and a heat insulating member 50 are installed in the chamber 10, and the mold member ( A molding mold 60 is charged inside the 20), and the molding mold 60 is composed of an upper molding plate 62 and a lower molding plate 61 . Upper and lower pressing members 31 and 32 are installed on the corresponding surfaces of the upper and lower molding plates of the molding mold, which are installed to correspond to each other so as to be able to rise and fall inside the mold member 20, have. Here, since the upper and lower molding plates 62 and 61 have a ring-shaped pattern integrally formed on the pressing surface, an edge ring having a ring shape can be manufactured in a single process. The shape of the forming mold 60 for obtaining a ring shape, that is, the upper and lower forming plates 62 and 61 is as shown in FIG. 3 , and ceramic powder is put between the upper and lower forming plates 62 and 61 and hot press (Hot Press) can minimize the process time and cost compared to the manufacturing process of the conventional edge ring.

The upper and lower molding plates 62 and 61 may each be composed of a graphite sheet, and the upper molding plate 62 is composed of one graphite sheet and carbon powder. it could be

In step b), it is preferable that the compact is subjected to pressure sintering at a temperature of 1,000 to 1,700° C. under a pressure condition of 10 to 50 MPa. If the temperature of the primary pressure sintering treatment is less than 1000 ° C, the sintering density of the compact is less than 90%, which is insufficient to perform the secondary pressure sintering treatment performed as a subsequent process, and when it exceeds 1700 ° C, the alumina constituting the primary sintered compact There is a problem in that the mechanical strength of the finally manufactured edge ring is lowered due to the growth of the particles.

Step b) is preferably performed under an inert gas atmosphere.

Next, step c) is a step of burying the electrode in the upper surface of the primary sintered body, specifically, by placing the electrode on the surface of the primary sintered body located in the molding mold in the hot press sintering apparatus may be buried.

The electrode is not particularly limited as long as it is an alloy that can be used as an electrode material, but preferably tungsten (W), molybdenum (Mo), silver (Ag), gold (Au), niobium (Nb), titanium (Ti), nitride It may be any one selected from aluminum (AIN) and alloys thereof, and more preferably molybdenum (Mo).

The electrode may have a wire type or a sheet type mesh structure. The mesh structure is a mesh structure in which a plurality of metals arranged in a first direction and a plurality of metals arranged in a second direction cross each other alternately.

Between steps c) and d), the method may further include c-1) loading the ceramic powder or the second sintered body on the upper surface of the first sintered body on which the electrode is seated. Specifically, after disposing the electrode (after step c), before secondary pressure sintering (before step d), ceramic powder may be additionally charged onto the electrode (step c-1). It is preferable to use the same ceramic powder as the ceramic powder of step a) as the additionally charged ceramic powder. The charging of the additional ceramic powder is not particularly limited as long as it is a general method.

It is preferable that the second sintered body is manufactured by the same process as the first sintered body. Specifically, the second sintered body and the first sintered body may have the same inner diameter and the same outer diameter. However, the thickness of the second sintered body may be smaller than that of the first sintered body, which may be appropriately selected according to the final design of the edge ring used in the electrostatic chuck.

The charging of the second sintered body is also not particularly limited as long as it is a general method, and in particular, it may be charged through a process in which the electrode is disposed on the upper surface of the first sintered body.

Next, step d) is a step of manufacturing an edge ring by secondary pressure sintering of the first sintered body on which the electrode is seated by a hot press.

In the second pressure sintering step, the first sintered body is preferably subjected to a hot press treatment for 0.5 to 6 hours while applying a pressure of 10 to 50 MPa at a temperature of 1,000 to 1,700° C. under an inert gas atmosphere.

If the temperature of the secondary pressure sintering treatment is less than 1000 ° C, problems such as a sintering density of less than 90% or a difference in density with the electrode may occur, and if it exceeds 1700 ° C, the mechanical strength of the finally manufactured edge ring is lowered there is a problem to be

In addition, the edge ring manufactured through the above manufacturing process does not require a process of using an ingot or a split mold, and can be directly manufactured as a ring-shaped edge ring, thereby shortening the manufacturing time of the edge ring and Manufacturing cost can be lowered.

That is, as the size of the wafer or electrostatic chuck increases, the size of the ingot used for manufacturing the edge ring increases. Accordingly, the cost increases exponentially as the size of the wafer or electrostatic chuck increases. However, in the present invention, since the ring-shaped (doughnut-shaped) edge ring can be directly manufactured with a ring-shaped molding mold through the hot press sintering process, the manufacturing cost is minimized and edge rings of various sizes can be manufactured.

In addition, in the conventional technique of manufacturing the edge ring as an assembly unit or a divided member, an adhesive must be used for bonding each unit or member, and there is a gap at the bonding site of each member, so that a non-uniform plasma environment when introduced into a plasma device In addition, there is a problem in that the yield of the plasma process is rapidly reduced due to gas generation by the adhesive. However, since the present invention manufactures a ring-shaped edge ring having one uniform density and thermal shock strength with a single device, it is possible to solve the problems of the prior art.

The edge ring of the present invention is prepared by mixing a ceramic powder, a surfactant, and water by the method for manufacturing an edge ring as described above, and then injecting the aqueous raw material slurry into a molding mold for hot press, and then hot The primary sintered body is prepared by charging it in a press sintering apparatus, and performing a primary pressure sintering treatment, and after disposing an electrode on the upper surface of the primary sintered body, it may be manufactured by performing a secondary pressure sintering treatment.

When a ring-shaped edge ring is manufactured through processing after manufacturing a conventional disc, the shrinkage behaves in the X, Y, and Z directions during the sintering process, but when manufactured by the above-described method, the shrinkage due to sintering is X, Since Y-direction shrinkage is suppressed and only Z-direction shrinkage behavior is used, it is possible to manufacture an edge ring that is much denser than the conventional edge ring method.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. However, these Examples are intended to illustrate the present invention in more detail, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited thereby.

Examples and Comparative Examples: Edge ring manufacturing

Aluminum oxide (Al ₂ O ₃ ) powder having an average particle diameter of about 0.4 μm was used. ZrO _{2 had} an average particle diameter of about 0.5 μm, and MgO had an average particle diameter of about 0.3 μm. A raw material powder was prepared by mixing the ceramic powders in each composition as shown in Table 1.

The powder mixed with the above composition was mixed by a wet ball milling process. Specifically, water was wet-mixed for 20 hours at a speed of 120 rpm using an alumina ball having a size of 8 mm as a solvent. In this case, an alcohol-based solvent may be used instead of water, and as long as it is a solvent used in the wet ball milling process, it is not particularly limited thereto.

The prepared raw material powder is put into a forming mold (wafer 12 inches) having an outer diameter (OD) of 350 mm and an inner diameter (ID) of 280 mm, and this is charged into a hot press sintering apparatus, press pressure 40 MPa, nitrogen atmosphere pressure 0.1 MPa As described in Table 1 below, pressure sintering was carried out for a predetermined time at a predetermined sintering temperature, respectively, and then cooling was performed. After high-temperature pressure sintering was performed, nitrogen gas was flowed at a flow rate of 1000 cc/min while the temperature was lowered and cooled to room temperature to prepare a primary sintered body. In the same manner, one more primary sintered body was prepared.

After placing an electrode (molybdenum, Mo) of a mesh structure on the upper surface of the primary sintered body, and loading another primary sintered body on the electrode, a press pressure of 40 MPa and a nitrogen atmosphere pressure of 0.1 MPa as described in Table 1 below Similarly, after secondary pressure sintering for a predetermined time at a predetermined sintering temperature, cooling was performed. After the secondary pressure sintering was performed, nitrogen gas was flowed at a flow rate of 1000 cc/min while the temperature was lowered and cooled to room temperature.

division composition, weight % 1st sintering condition Secondary sintering conditions Al ₂ O ₃ ZrO ₂ MgO Example 1 94.6 5.0 0.4 1400 °C, 1 h, 40 MPa 1700 °C, 1 h, 40 MPa Example 2 96.4 3.5 0.1 1400 °C, 1 h, 40 MPa 1700 °C, 1 h, 40 MPa Comparative Example 1 91 7.0 2.0 1400 °C, 1 h, 40 MPa 1700 °C, 1 h, 40 MPa Comparative Example 2 99 0.9 0.1 1400 °C, 1 h, 40 MPa 1700 °C, 1 h, 40 MPa Comparative Example 3 100 0 0 1400 °C, 1 h, 40 MPa 1700 °C, 1 h, 40 MPa

Example 3: Edge ring manufacturing

Aluminum oxide (Al ₂ O ₃ ) powder having an average particle diameter of about 0.4 μm was used. ZrO _{2 had} an average particle diameter of about 0.5 μm, and MgO had an average particle diameter of about 0.3 μm. A raw material powder was prepared by mixing the ceramic powders in each composition as shown in Table 1.

The powder mixed with the above composition was mixed by a wet ball milling process, and specifically, water was wet-mixed at a speed of 120 rpm for 20 hours using an alumina ball having a size of 8 mm as a solvent.

The raw material powder prepared in the same manner as in Example 2 was put into a molding mold (wafer 12 inches) having an outer diameter (OD) of 330 mm and an inner diameter (ID) of 300 mm, and press-molded. After transferring the molded body to a molding mold for hot press, it was charged into a hot press sintering apparatus, pressurized under the same conditions as in Example 2 under a press pressure of 40 MPa and a nitrogen atmosphere pressure of 0.1 MPa, followed by cooling. After high-temperature pressure sintering was performed, nitrogen gas was flowed at a flow rate of 1000 cc/min while the temperature was lowered and cooled to room temperature to prepare a primary sintered body. In the same manner, one more primary sintered body was prepared.

After placing an electrode (molybdenum, Mo) of a mesh structure on the upper surface of the primary sintered body, and loading another primary sintered body on the electrode, the same conditions as in Example 2 under a press pressure of 40 MPa and a nitrogen atmosphere pressure of 0.1 MPa After secondary pressure sintering with a furnace, cooling was performed. After the secondary pressure sintering was performed, nitrogen gas was flowed at a flow rate of 1000 cc/min while the temperature was lowered and cooled to room temperature.

Comparative Example 4: Manufacturing of an edge ring by a conventional method

Using the ceramic raw material powder having the same composition as in Example 2, an edge ring was manufactured by a conventional method. The ceramic raw material powder was mixed by a wet ball milling process. Specifically, water was wet-mixed at a speed of 120 rpm for 20 hours using an alumina ball having a size of 8 mm as a solvent. In this case, an alcohol-based solvent may be used instead of water, and as long as it is a solvent used in the wet ball milling process, it is not particularly limited thereto.

The prepared raw material powder was put into a mold (wafer 12 inches) having an outer diameter (OD) of 350 mm to prepare a disk molded body, and after degreasing, a hot press sintering device was used to first pressurize it under a pressure of 40 MPa and a nitrogen atmosphere pressure of 0.1 MPa. sintered. After high-temperature pressure sintering was performed, nitrogen gas was flowed at a flow rate of 1000 cc/min while the temperature was lowered and cooled to room temperature to prepare a primary sintered body. Thereafter, after primary processing with a disk, an electrode (molybdenum, Mo) of a mesh structure is placed on the upper surface of the primary sintered body, and a sintered body prepared in the same manner as the primary sintered body is charged on the electrode, followed by a press pressure of 40 After secondary pressure sintering under MPa and a nitrogen atmosphere pressure of 0.1 MPa, cooling was performed. After the secondary pressure sintering was performed, nitrogen gas was flowed at a flow rate of 1000 cc/min while the temperature was lowered and cooled to room temperature.

Through secondary processing of cutting the center of the disk-shaped secondary sintered body embedded with the electrode, a ring-shaped edge ring (outer diameter (OD) of 330 mm, inner diameter (ID) of 300 mm) was manufactured.

Experimental Example 1. Density and porosity analysis

The density and porosity of the edge rings (10 specimens each) prepared in Example 2 and Comparative Example 4 were measured with a density meter (MCI, Sartorious, Japan) using the Archimedes principle, and the results are shown in Table 2. In this case, a scale having a resolution of 0.0001 gr was used.

division Density (g/cm ³ ) Porosity (%) Example 2 3.95~3.99
(average: 3.98) 0.03~0.05
(average: 0.04) Comparative Example 4 3.50~3.85
(average: 3.61) 0.10 to 0.19
(average: 0.16)

As can be seen in Table 2, it can be seen that, although the edge ring manufactured according to the manufacturing method of the present invention is manufactured in a ring shape, it is manufactured more densely and densely than the edge ring manufactured by the conventional manufacturing method.

As a result of comparing the amount of material input to manufacture a large-diameter edge ring having an inner diameter of 280 mm and an outer diameter of 350 mm, the amount of material input in Example 2 (8,551 ~ 6500 gr) was compared to Comparative Example 4 (32,231 ~ 16,000 gr), 60 ~ It was confirmed that a 75% reduction was achieved.

Nevertheless, it was confirmed that the edge ring of Example 2 was manufactured more densely than the edge ring of Comparative Example 4.

In addition, in order to check whether the edge ring of Example 2 and the edge ring of Comparative Example 4 were uniformly formed, 10 places were randomly selected on the surface of each edge ring, and the density and porosity were measured for this, and then the average and The standard deviation was calculated. As a result, it was confirmed that the edge ring of Example 2 had an average density of 3.977 ± 0.013 g/cm ³ , and a porosity of 0.04 ± 0.008%, and the edge ring of Comparative Example 4 had an average density of 3.903 ± 0.042 g/cm ³ , and a porosity of 0.09 ± 0.015% It was confirmed that It can be seen that the edge ring of Example 2 has overall higher density characteristics than the edge ring of Comparative Example 4 is formed uniformly.

Experimental Example 2: Thermal shock analysis

The edge rings prepared in Example 2 and Comparative Example 3 were prepared, and the bending strength was measured therefrom. Each edge ring was heated to a high temperature, and the bending strength was measured before and after rapid cooling. Bending strength was measured by machining the edge ring to a size of 10 x 10 x 1 mm through plane grinding and cutting, and then using a universal testing machine (Allentech UCT-5T) at a crosshead speed of 0.5 mm/min in a 30 mm span. The three-point flexural strength was measured (ISO 6872) (refer to the drawings below).

[Measurement process]

division Average bending strength (MPa) Before quenching After quenching Example 2 390 154 Comparative Example 3 390 130

As shown in Table 3, when the temperature was raised to a high temperature and then quenched, the difference in bending strength was compared. As a result, it was confirmed that the reduction in bending strength of the edge ring of Example 2 was significantly lower than that of the edge ring of Comparative Example 3.

That is, even if manufactured in the same process step, it can be seen that the composition of the ceramic powder is important in order to directly manufacture the ring-shaped edge ring with the ring-shaped molding mold of the present invention.

Although not shown in Table 3, it was confirmed that the edge rings of Examples 1, 2, and 4 also significantly reduced the bending strength to 100 to 110 MPa after quenching.

Experimental Example 3: Microstructure analysis

The edge ring prepared in Example 2 was prepared, and it was measured with a scanning electron microscope (SEM). After the edge ring was processed to a size of 10 × 10 × 1 mm through plane grinding and cutting, the surface texture was analyzed by magnifying the surface by 10k with a scanning electron microscope (SEM).

5 is a microstructure photograph of the central portion of the edge ring prepared in Example 2 of the present invention, and FIG. 6 is a microstructure photograph of the portion in which the electrode is embedded in the edge ring prepared in Example 2 of the present invention. , Figure 7 is a microstructure photograph of the right part in which the electrode is embedded in the edge ring prepared in Example 2 of the present invention, 5c, e are enlarged photos of 5b, d, 6c is an enlarged photo of 6b, , 7c is an enlarged picture of 7b.

As shown in FIGS. 5 to 7 , it was confirmed that both the central part of the edge ring prepared in Example 2 and the part in which the electrode was embedded form a dense structure. In particular, in the edge ring, there is no difference between the microstructure of the electrode and the surface of the ceramic, and it can be seen that it is dense.

Experimental Example 4: Thermal distribution analysis

The edge ring prepared in Example 2 was bonded to the electrostatic chuck (FIG. 9).

Thermal diffusivity of the electrostatic chuck to which the edge ring is coupled was measured and analyzed using a laser flash device, and the results are shown in FIG. 8 .

8 is a photograph of measuring the thermal distribution of an electrostatic chuck having an edge ring manufactured in Example 2 of the present invention. According to this, the electrostatic chuck having an edge ring manufactured according to the present invention was heated to 100° C., and the temperature was measured by contacting 20 parts shown in FIG. 8 , as shown in Table 4.

Item Details Set Temp 100 ℃ measurement 20 places, contact type result Average temperature: 102.9 ℃ ΔT: 3.6 °C (max)

As shown in Table 4, it was confirmed that almost similar temperatures were measured in all parts of the edge ring where the measurement was performed. That is, through the analysis result, it can be confirmed that the edge ring having a more uniform thermal distribution than the existing edge ring can be manufactured through the manufacturing method of the present invention.

Claims (7)

a) injecting the ceramic powder into a ring-shaped molding mold;
a-1) preparing a molded body by pressing the molding mold prepared in step a), and transferring it to a ring-shaped molding mold for hot press;
b) preparing a first sintered body by loading the molding mold into a chamber of a hot press sintering apparatus and performing primary pressure sintering;
c) embedding an electrode in the upper surface of the first sintered body; and
d) manufacturing an edge ring by secondary pressure sintering of the first sintered body on which the electrode is seated by a hot press; delete According to claim 1,
The ceramic powder comprises 94.6 to 98.6 wt% of Al ₂ O ₃ , 1 to 5 wt% of ZrO ₂ and 0.05 to 0.5 wt% of MgO. According to claim 1,
Step b) is a method of manufacturing an edge ring, characterized in that it is performed under an inert gas, at a temperature of 1000 to 1700 ℃ pressure of 10 to 50 MPa. According to claim 1,
The step d) is a method of manufacturing an edge ring, characterized in that it is performed under an inert gas, at a temperature of 1000 to 1700 ℃ pressure of 10 to 50 MPa. According to claim 1,
Between steps c) and d),
c-1) charging the ceramic powder on the upper surface of the first sintered body on which the electrode is seated; According to claim 1,
After step d),
e) a quenching step of rapidly cooling the edge ring manufactured in step d);

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