KR20210106969A - Manufacturing method for plasma resistance edge ring using prepress and the plasma resistance edge ring using thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a plasma resistance edge ring, in which the edge ring can be manufactured by using a number of preformed specimens with uniformity secured through a prepress process so that 30 to 60% of additional space in a mold in comparison with a case of using sample powder immediately during a hot-press sintering process can be secured, thereby providing effects of manufacturing edge rings at least twice per one process, preventing introduction of impurities, and minimizing a separate post-processing process, such as wire cutting and the like, after a sintering process. In addition, since a cold isostatic pressure treatment is performed on the preformed specimen by the prepress process, foreign substances are removed from the specimen and the density deviation of the specimen is minimized, and distortion of the specimen during the hot-press sintering can be effectively prevented, thereby providing an effect of enabling the sintered density of the edge ring manufactured through the hot-press sintering process to correspond to 95 to 99.9% of the theoretical value. The method comprises a granulated powder manufacturing step, a ceramic specimen manufacturing step, a density deviation removing step, and a hot-press sintering step.

Description

Plasma-resistant edge ring manufacturing method using prepress and plasma-resistant edge ring manufactured accordingly

The present invention relates to a plasma-resistant edge ring manufacturing method using a prepress and a plasma-resistant edge ring manufactured accordingly.

The semiconductor wafer manufacturing process is continuously developing through the reversal of technology and the miniaturization of line width and increase in the number of stacks. On the other hand, there is a need for the ceramic components for semiconductor manufacturing used therein to withstand the increasingly severe plasma, and accordingly, the properties of these ceramic components also need to be improved.

For example, a plasma apparatus (chamber) in which plasma etching is performed includes an electrostatic chuck including an upper electrode and an electrode at a lower portion, and a covering assembly surrounding the electrostatic chuck to protect the electrostatic chuck from plasma generated in the plasma processing chamber, , a substrate such as a semiconductor wafer or a glass substrate is supported on the upper surface of the electrostatic chuck. With this configuration, as power is applied between the upper electrode and the lower electrostatic chuck, plasma (P) is generated in the plasma process chamber by the electric field effect, and the ions are incident in the direction toward the electrostatic chuck, and the chemical reaction of plasma ions and Etching is performed on the substrate using kinetic energy.

Meanwhile, the covering assembly surrounding the electrostatic chuck may have a configuration in which a coupling groove is formed on a lower surface of an edge ring and an electrode ring is coupled thereto, and the edge ring surrounds a side surface of a substrate supported on an upper surface of the electrostatic chuck. is a ceramic component for semiconductor manufacturing manufactured in a three-dimensional shape of a standard and environment capable of maintaining the same height as a substrate supported by an electrostatic chuck.

On the other hand, the existing edge ring was manufactured and used with single crystal silicon (Silicon) or quartz (Quartz), but this composition is excessively etched under harsh plasma conditions, so maintenance is required after a short time use or replacement with new parts is a problem there was Therefore, today, the edge ring is manufactured using a sintered body using a non-oxide-based structural material such as silicon carbide, boron carbide, and silicon nitride. As one of the methods with excellent characteristics of the sintered body, it is being applied to the manufacturing process of edge rings, which are ceramic parts for semiconductor manufacturing.

However, according to the hot pressing sintering method, there is a problem that the density deviation of the specimen increases as the pressing area increases, and there is a risk of mold breakage due to the occurrence of imbalance in the sintered specimen. In addition, according to the above method, the period per unit operation is long and the specific surface area is large, so the number of sintered bodies that can be produced during one process is small, so the process cost is very high. There is a problem in that the working time is lengthened by repetitive processes such as raising the carbon sheet, raising the spacer for uniform pressurization, and then raising the carbon sheet again. In addition, according to the above method, there may be a problem that foreign substances are introduced during the sample loading procedure.

In order to solve the above problems, the present invention provides hot press sintering of a preformed specimen through prepressing and cold isostatic pressing (CIP) processing, so that the sintering density is 95 to 95 to the theoretical value. It is to provide a plasma-resistant edge ring manufacturing method capable of producing a plasma-resistant edge ring of 99.9% and a plasma-resistant edge ring manufactured thereby.

In an embodiment of the present invention for achieving the above object, a) at least one sample selected from the group _{consisting of silicon carbide (SiC), boron carbide (B 4} C) and silicon nitride (Si ₃ N _{4 ) is pretreated and granulated} preparing a powder; b) pre-forming the granulated powder through a prepress (PrePress) to prepare a ceramic specimen; c) removing the density deviation of the specimen by cold isostatic pressing (CIP) treatment of the ceramic specimen; and d) laminating the specimen in a mold and hot pressing sintering; It provides a plasma-resistant edge ring manufacturing method comprising a.

In another embodiment of the present invention, the pretreatment of step a is performed by adding an antifoaming agent, a releasing agent and a binder, to provide a plasma-resistant edge ring manufacturing method.

In another embodiment of the present invention, the prepress of step b provides a plasma-resistant edge ring manufacturing method, which is performed by uniaxially pressing after filling and leveling the granulated powder in a mold .

In another embodiment of the present invention, the cold isostatic pressure treatment of step c is performed by pressing for 1 to 10 minutes under a pressure condition of 1,000 to 2,000 bar, providing a plasma-resistant edge ring manufacturing method.

In another embodiment of the present invention, the hot pressure sintering of step d is to be performed in a mold of a multi-layer laminate structure capable of sintering a plurality of specimens at the same time, it provides a plasma-resistant edge ring manufacturing method.

In another embodiment of the present invention, as a plasma-resistant edge ring manufactured by the above method, the sintered density of the edge ring is 95 to 99.9% of the theoretical value, providing a plasma-resistant edge ring.

According to the plasma-resistant edge ring manufacturing method of the present invention, the edge ring can be manufactured using a plurality of preformed specimens with uniformity secured through the prepress process, so the sample powder is directly used during hot pressing sintering processing. 30 to 60% of additional space in the mold can be secured compared to the case of It has the effect of minimizing the post-processing process.

In addition, according to the plasma-resistant edge ring manufacturing method of the present invention, by performing a cold isostatic pressure treatment on the pre-formed specimen by the prepress process, the penetration of foreign matter between the charges of the specimen is reduced, and the density deviation of the specimen is reduced. It is possible to effectively prevent distortion of the specimen during hot pressing sintering by minimizing it, and accordingly, the sintered density of the edge ring manufactured through hot pressing has an effect that corresponds to 95 to 99.9% of the theoretical value.

1 is a schematic diagram briefly showing a prepress process according to an embodiment of the present invention.
2 schematically shows a shape in which a plurality of preformed specimens are stacked through a prepress process according to an embodiment of the present invention.
3 schematically shows a mold shape of a multilayer laminate structure in which hot pressing sintering is performed according to an embodiment of the present invention.
4 schematically shows a mold shape of a multilayer laminate structure in which hot pressing sintering is performed according to another embodiment of the present invention.
5 is a cross-sectional view showing that a carbon sheet is provided between the laminated specimens during hot press sintering according to another embodiment of the present invention.

Since the invention may have various modifications and various forms, specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed form, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the invention.

Hereinafter, a plasma-resistant edge ring manufacturing method according to a specific embodiment of the present invention and a plasma-resistant edge ring manufactured thereby will be described.

First, as described above, today's edge rings are manufactured using a sintered body obtained by hot-pressure sintering of non-oxide-based structural materials such as silicon carbide, boron carbide, and silicon nitride. There is a problem in that the density deviation of In addition, according to the above method, the period per unit operation is long and the specific surface area is large, so the number of sintered bodies that can be produced during one process is small, so the process cost is very high. There is a problem in that the working time is lengthened by repetitive processes such as raising the carbon sheet, raising the spacer for uniform pressurization, and then raising the carbon sheet again. In addition, according to the above method, there may be a problem that foreign substances are introduced during the sample loading procedure.

The present inventors, paying attention to the above problems, in the case of hot pressing and sintering a preformed specimen through prepress and cold isostatic pressing (CIP) processing, a plurality of Since it is possible to manufacture edge rings using preformed specimens, 30 to 60% of additional space in the mold can be secured compared to using sample powder directly during hot-pressing sintering, so edge rings at least 3 times or more per process can be manufactured, impurities can be prevented, and additional post-processing processes such as wire cutting after sintering are minimized. It is possible to effectively prevent distortion of the specimen during hot-press sintering processing, and it is confirmed through experiment that the sintering density of the edge ring manufactured accordingly is 95 to 99.9% of the theoretical value and thus the deviation is minimized, and the present invention completed.

Plasma resistance Edgering Manufacturing method

Specifically, the plasma-resistant edge ring manufacturing method according to an embodiment of the present invention is a) one selected from the group _{consisting of silicon carbide (SiC), boron carbide (B 4} C) and silicon nitride (Si ₃ N _{4 )} preparing a granulated powder by pre-treating the above sample; b) pre-forming the granulated powder through a prepress (PrePress) to prepare a ceramic specimen; c) removing the density deviation of the specimen by cold isostatic pressing (CIP) treatment of the ceramic specimen; and d) laminating the specimen in a mold and hot pressing sintering; may include.

First, at least one sample selected from the group consisting of silicon carbide (SiC), boron carbide (B ₄ C) and silicon nitride (Si ₃ N ₄ ) is pretreated to prepare a granulated powder (step a).

Silicon carbide (SiC), boron carbide (B ₄ C) and silicon nitride (Si ₃ N ₄ ) are non-oxide-based structural materials, with mechanical properties such as high strength, high hardness and abrasion resistance as well as oxidation resistance, corrosion resistance, and low thermal conductivity. And it is a main material of ceramics having thermal properties such as high thermal shock resistance and high temperature strength due to the coefficient of thermal expansion. In particular, the non-oxide-based structural material has a strong covalent bond due to the characteristics of the material, and the energy of the grain boundary is high, and the diffusion rate of the grain boundary is low, so that there is a considerable difficulty in molding through sintering.

Meanwhile, according to an embodiment of the present invention, one or more samples selected from the group consisting of silicon carbide (SiC), boron carbide (B ₄ C) and silicon nitride (Si3N _{4 ) as the non-oxide-based structural material are pre-treated,} It is prepared as a granulated powder. In particular, the preparation of the sample as a granulated powder is for the granulation form to increase the flowability of the powder form, and thus for a smooth process progress during the prepress process. , a release agent and a binder may be added to prepare a granulated powder having a particle diameter of about 10 to 100 μm.

Next, the granulated powder is preformed through a prepress (PrePress) to prepare a ceramic specimen (step b).

The prepress of the above step is a process performed to manufacture a plurality of preformed specimens with secured uniformity. In the case of hot-pressing sintering, which will be described later, using the preformed specimen through the above process, a conventional sample powder is used. Compared to the direct use method, it is possible to secure an additional space of 30 to 60% in the mold, making it possible to manufacture at least two or more edge rings per one process, effectively preventing the ingress of impurities during hot-pressing sintering processing, and also There is an effect that it is possible to minimize a separate post-processing process such as wire cutting after sintering.

On the other hand, the prepress of this step may be performed by first preparing a mold for prepress, filling the mold with the granulated powder of the sample prepared in step a, leveling, and then uniaxially pressing (Fig. see 1).

Specifically, the above process fills the mold with granulated powder and then fills the sample uniformly through flattening of the top surface, but fills only the own weight of the powder without partial pressure or relief, and then pushes out the unnecessary upper part. can be done in this way.

Next, a preformed specimen is prepared by uniaxially pressing the filled granulated powder, and the pressing condition may be performed by pressing within the range of 50 to 150 kg/cm2.

Next, the ceramic specimen is subjected to cold isostatic pressing (CIP) to remove the density deviation of the specimen (step c).

The cold isostatic pressing removes foreign substances from the specimen with respect to the preformed specimen obtained through step b, and minimizes the density deviation of the specimen to effectively prevent distortion of the specimen during hot pressing sintering, which will be described later. it could be

Specifically, the cold isostatic pressing method of this step may be performed by pressurizing a liquid at 1,000 to 2,000 bar for 1 to 10 minutes, specifically for 5 minutes, as a pressure medium in order to equalize the density of the specimen, and the above process Through this, the preformed specimen is subjected to uniform pressure in all directions, so that the density deviation between products is minimized.

Meanwhile, foreign matter on the preformed specimen is removed through the above step, and a preformed specimen having a uniform shape can be obtained. In addition, the plurality of specimens obtained through the above step can be easily separated by inserting a carbon sheet member between the specimen and the specimen by using a carbon sheet member to prevent bonding between the specimens, and as the laminated form is described later. It may also be put into a mold for pressure sintering (see FIG. 2).

Next, the specimen obtained in step c is laminated in a mold and sintered under hot pressure (step d).

On the other hand, as a sintering molding method for obtaining a dense sintered body reaching theoretical density mainly using ceramics, etc., there are atmospheric sintering method, reaction sintering method, recrystallization method, oxide bonding method, hot pressing sintering method, and the like.

In the present invention, for the production of a sintered body, a hot pressure sintering method can be used to achieve densification close to the theoretical density at a temperature lower than atmospheric sintering without a sintering aid or with a minimum amount of non-oxide ceramics, which is difficult to sinter, can be used.

Specifically, a specimen obtained in the above step c as the temperature and 50kgf / cm ² to 220kgf / cm ² pressure of 1900 to 2100 ℃ range charged, and in the mold provided in the furnace (furnace), and more particularly 2100 ℃ temperature And 186 kgf / cm ² It is possible to form a sintered compact by uniaxial pressure under pressure conditions.

On the other hand, the mold used in the above step is a configuration for manufacturing the sintered body, for example, a graphite material may be used, and a plurality of specimens may be sintered at the same time in a mold of a multi-layered laminate structure.

More specifically, the mold according to an embodiment of the present invention includes a mold die provided on the outermost outer circumferential surface, an outer sleeve provided inside the mold die, and an inner spaced apart from the outer sleeve inside the outer sleeve by a predetermined distance. One or more mold units including a sleeve, a core disposed in the inner sleeve, an upper punch formed at an upper end of a space spaced apart between the outer sleeve and the inner sleeve, and a lower punch formed at a lower end of the spaced space. ), and may include a base formed on the upper and lower portions of the one or more mold units, respectively.

Specifically, as shown in FIG. 3 , in the mold of the multilayer stack structure according to an embodiment of the present invention, two mold units are provided between an upper base and a lower base, and a coupling base is provided between the two mold units. is provided, and each mold unit is disposed with the coupling base as a boundary. On the other hand, the mold according to another embodiment of the present invention may include two or more mold units (units), in this case, the mold units may be stacked on the basis of the coupling base as described above and disposed as a boundary, The coupling base may be provided between each mold unit.

On the other hand, the sleeve has a trapezoidal cross-sectional shape, is provided to facilitate demolding of the sintered body, may have a divided structure, prevent direct contact between the die and the sintered body, and is easy to separate and replaceable. . On the other hand, the core is provided to fix the inner sleeve, and has a feature of reducing defects resulting from the difference in thermal expansion due to cooling of the sintered body. In this case, since the inner core is easily demolded, it is possible to effectively prevent damage to the sintered body during demolding.

On the other hand, the punch serves to form the sintered body in a desired shape by adjusting the gap between the upper punch and the lower punch according to a desired shape when manufacturing the sintered body.

On the other hand, a hole may be formed inside the core, and when the hole is formed inside the core, shrinkage stress during cooling after sintering the sintered body is reduced to minimize defects in the sintered body.

On the other hand, the component of the mold may additionally include a carbon sheet (not shown), which is provided to facilitate demolding, prevent contamination, and match thermal expansion, specifically 0.5 mm to 5 mm Carbon sheets in a range of thicknesses may be used.

Plasma resistance Edgering

On the other hand, the sintering density of the plasma-resistant edge ring manufactured according to the plasma-resistant edge ring manufacturing method according to an embodiment of the present invention may be 95 to 99.9% of the theoretical value, and by this characteristic, the plasma resistance and corrosion resistance are very excellent.

According to the plasma-resistant edge ring manufacturing method of the present invention described above, it is possible to manufacture the edge ring using a plurality of preformed specimens with uniformity secured through the prepress process, so that the sample powder during hot pressing sintering processing It is possible to secure an additional space of 30 to 60% in the mold compared to the case of directly using There is an effect that separate post-processing processes such as cutting are minimized.

In addition, according to the plasma-resistant edge ring manufacturing method of the present invention, by performing a cold isostatic pressing treatment on a specimen pre-formed by a prepress process, foreign matter in the specimen is removed, and the density deviation of the specimen is minimized to minimize the hot It is possible to effectively prevent distortion of the specimen during the pressure sintering processing, and accordingly, the sintering density of the edge ring manufactured through the hot pressing sintering processing corresponds to 95 to 99.9% of the theoretical value, thereby minimizing the deviation.

Hereinafter, the action and effect of the invention will be described in more detail through specific examples of the invention. However, this is presented as an example of the invention and the scope of the invention is not limited in any sense by this.

Example One

Prepare 1000 g of boron carbide powder, mix 2 g of CONTRASPUM as an antifoaming agent, 10 g of ethylene glycol as a mold release agent, and 30 g of polyvinyl alcohol as a binder. got

Next, the granulated boron carbide powder was filled in the prepared mold for prepress and leveling was performed, and then a boron carbide specimen was prepared by uniaxially pressing at 80 kg/cm 2 , and it was prepared by laminating it in three layers.

Next, the stacked boron carbide specimen was pressurized for 5 minutes under 1500 bar conditions using a CIP apparatus to perform a cold isostatic pressing process.

Next, the specimen obtained through the above step was charged into a mold for hot pressing, and uniaxially pressed at a temperature of 2100° C. and a pressure of 186 kgf/cm 2 to form a sintered body. The sintered body may be used as an edge ring product constituting the covering assembly in the plasma apparatus without a separate post-processing process.

comparative example One

A sintered body for a plasma-resistant edge ring was prepared in the same manner as in Example 1,

After filling the inside of the mold with the granulated powder prepared in Example 1, it was charged into a mold for hot pressing, and uniaxially pressed at 2100° C. and 186 kgf/cm 2 pressure to form a sintered body.

a0: granulated sample powder m: mold for prepress
a: preformed specimen r: flattening means
b: carbon sheet
110: mold die 120: outer sleeve
130: inner sleeve 140: core
150: upper punch 160: lower punch
20: combined base 30: upper base
40: lower base

Claims (7)

a) preparing a granulated powder by pre-treating at least one sample selected from the group consisting of silicon carbide (SiC), boron carbide (B ₄ C) and silicon nitride (Si ₃ N _{4 );}
b) pre-forming the granulated powder through a prepress (PrePress) to prepare a ceramic specimen;
c) removing the density deviation of the specimen by cold isostatic pressing (CIP) treatment of the ceramic specimen; and
d) stacking the specimen in a mold and sintering under hot pressure; Plasma-resistant edge ring manufacturing method comprising a.
The method of claim 1,
The pretreatment of step a is performed by adding an antifoaming agent, a releasing agent and a binder, a plasma-resistant edge ring manufacturing method.
The method of claim 1,
The prepress of step b is to be performed by uniaxially pressing after filling the granulated powder in a mold and leveling (Leveling), plasma-resistant edge ring manufacturing method.
The method of claim 1,
The cold isostatic pressure treatment of step c is performed by pressing for 1 to 10 minutes under a pressure condition of 1,000 to 2,000 bar, a plasma-resistant edge ring manufacturing method.
The method of claim 1,
The hot pressing sintering of step d is to be performed in a mold of a multi-layered laminate structure capable of sintering a plurality of specimens at the same time, plasma-resistant edge ring manufacturing method.
The method of claim 1,
A method of manufacturing a plasma-resistant edge ring, wherein a carbon sheet member is provided between the laminated specimen and the specimen during hot press sintering in step d.
As a plasma-resistant edge ring manufactured by the method of claim 1,
The sintered density of the edge ring is 95 to 99.9% of the theoretical value, plasma resistance edge ring.

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