KR102541331B1 - Plasma resistant material with added fine particles and manufacturing method thereof - Google Patents

Abstract

According to the plasma-resistant edge ring manufacturing method according to the present invention, since it is possible to manufacture edge rings using a plurality of pre-formed specimens whose uniformity is secured through the pre-press process, sample powder is immediately prepared during hot press sintering. It is possible to secure 30 to 60% of additional space in the mold compared to the case of using it, so that at least twice as many edge rings can be manufactured per one process, and it is possible to prevent the inflow of impurities, and also, after sintering, wire cutting, etc. There is an effect that a separate post-processing process is minimized. In addition, by performing the cold isostatic pressure treatment on the specimen preformed by the prepress process, foreign matter is removed from the specimen and the density deviation of the specimen is minimized to effectively prevent distortion of the specimen during hot press sintering. , Accordingly, there is an effect that the sintered density of the edge ring manufactured through the hot press sintering corresponds to 95 to 99.9% of the theoretical value.

Description

Plasma resistant material with fine particles added and manufacturing method thereof

The present invention relates to a plasma resistant material composed of a ceramic resin composite and a method for manufacturing the same.

The semiconductor wafer manufacturing process continues to evolve through technological reversals, miniaturization of line width and increase in the number of layers. On the other hand, as the plasma environment in the semiconductor manufacturing chamber gradually becomes harsh, ceramic parts for semiconductor manufacturing used in the chamber need to have high plasma resistance.

For example, a plasma device (chamber) in which plasma etching is performed is composed of an electrostatic chuck including an upper electrode and a lower electrode, and a covering assembly surrounding the electrostatic chuck to protect the electrostatic chuck from plasma generated in the plasma process 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 an electric field effect, and ions are incident in a direction toward the electrostatic chuck, and chemical reactions 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 the 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 manufacturing a semiconductor 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, conventional edge rings were made of single crystal silicon or quartz, but these compositions were excessively etched under harsh plasma conditions, requiring maintenance after a short period of use or replacement with new parts. there was

Therefore, today, edge rings are manufactured using sintered bodies using non-oxide-based structural materials such as silicon carbide, boron carbide, and silicon nitride. As one of the methods with excellent properties of the sintered body, it is applied to the manufacturing process of edge ring, which is a ceramic part for semiconductor manufacturing.

In general, the above-described sintered body is molded by a hot press method. Specifically, when performing the hot press method, particles having sub-micro size are used, and a sample having particles of this size is filled in a carbon mold and then molded into a sintered body by high temperature and high pressure. will be.

However, according to the above method, since a difference in pressure gradient is unavoidable, there is a problem in that non-uniformity may occur in the microstructure of the specimen. If the specimen is molded non-uniformly, not only the physical strength of the sintered body is reduced, but also has the disadvantage of non-uniform electrical properties for each microstructure of the sintered body. Furthermore, a problem in which a mold used to fill a specimen may be damaged may occur.

A technical problem of the present invention is to provide a resistance-adjustable ceramic composite of a plasma-resistant material and a manufacturing method thereof.

In addition, an object of the present invention is to provide a plasma resistant material to which fine particles are added and a manufacturing method thereof in order to improve the uniformity of a ceramic composite used in semiconductor manufacturing.

In order to solve this problem, in the present invention, by performing semi-sintering and impregnating the semi-sintered specimen with additives, the additive is filled between the semi-sintered microstructures, thereby raising the relative density of the semi-sintered specimen. It is to lower the degree of heat treatment and increase the sintered density during resintering.

According to the present invention, there is an advantage in that the uniformity of the sintered body is secured and the strength is improved.

In addition, since the sintered body according to the present invention is processed in a state of low relative density through a semi-sintering process, there is an advantage in that the convenience of processing is improved.

1 is a schematic diagram briefly showing a prepress process according to an embodiment of the present invention.
2 schematically shows a stacked shape of a plurality of specimens preformed through a prepress process according to an embodiment of the present invention.
3 schematically illustrates a mold shape of a multi-layer laminated structure in which hot-press sintering is performed according to an embodiment of the present invention.
4 schematically shows a mold shape of a multi-layer laminated structure in which hot-press sintering is performed according to another embodiment of the present invention.
5 is a cross-sectional view showing that carbon sheets are provided between laminated specimens during hot-press sintering according to another embodiment of the present invention.
6 is a flowchart illustrating a method of manufacturing a ceramic composite according to an embodiment of the present invention.

Since the invention can have various changes and various forms, specific embodiments will be exemplified and described in detail below. However, it should be understood that this is not intended to limit the invention to a particular disclosed form, and includes all modifications, equivalents, and substitutes included in the spirit and scope of the invention.

Hereinafter, a method for manufacturing a plasma resistant edge ring 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 sintered bodies obtained by hot-pressing sintering of non-oxide-based structural materials such as silicon carbide, boron carbide, and silicon nitride. According to the hot-pressing sintering method, as the area to be pressed increases, the specimen There is a problem that the deviation of the density becomes large, and there is a risk of mold damage due to the imbalance of the sintered specimen. In addition, according to the above method, there is a problem in that the unit cost of the process is very high because the number of sintered bodies that can be produced in one process is small because the period per unit operation is long and the specific surface area is large. There is a problem in that the working time is prolonged due to repetitive processes such as raising the carbon sheet, raising the spacer for uniform pressure, and then raising the carbon sheet again. In addition, according to the above method, there may be a problem in that foreign substances are introduced during the sample loading procedure.

The inventors of the present invention, focusing on the above problems, in the case of hot pressing and sintering a preformed specimen through PrePress and Cold Isostatic Pressing (CIP) treatment, a plurality of uniformity secured Since the edge ring can be manufactured using the preformed specimen, it is possible to secure 30 to 60% of additional space in the mold compared to the case of using the sample powder directly during hot press sintering, so that the edge ring is at least 3 times more per one process. It is possible to manufacture, and the introduction of impurities can be prevented.

On the other hand, a CIP mold is required for CIP processing, which reduces the convenience of work as the size of the specimen increases.

Therefore, in the present invention, before the specimen is completely sintered, the fine particles composed of the same composition as the specimen are impregnated, and the CIP treatment can be performed after the impregnation is performed. Accordingly, it is possible to secure the convenience of work together with the effect of improving the uniformity by CIP treatment.

Plasma resistant edge ring 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-processing the above sample; b) preparing a ceramic specimen by pre-molding the granulated powder through a prepress; c) removing the density variation of the ceramic specimen by cold isostatic pressing (CIP) treatment; and d) stacking the specimens in a mold and performing hot-press sintering; can 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 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 that have mechanical properties such as high strength, high hardness and wear resistance, as well as oxidation resistance, corrosion resistance, and low thermal conductivity. It is a main material of ceramics having thermal properties such as high thermal shock resistance and high temperature strength due to thermal expansion coefficient. In particular, the non-oxide-based structural material forms a strong covalent bond due to its material characteristics, has high grain boundary energy and low grain boundary diffusion rate, making it difficult to form through sintering.

On the other hand, according to an embodiment of the present invention, as the non-oxide-based structural material, 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 obtain It is prepared as a granulated powder. In particular, the preparation of the sample with granulated powder is to increase the flowability of the powder form in the granulated form, thereby smoothing the process during the pre-press process, and to prepare the sample with granulated powder, the antifoaming agent is added to the sample. , It can be prepared into granulated powder having a particle diameter of about 10 to 100㎛ by adding a release agent and a binder.

Next, the granulated powder is pre-molded through a prepress to prepare a ceramic specimen (step b).

The prepress in the above step is a process performed to manufacture a plurality of preformed specimens with uniformity secured. In the case of hot press sintering, which will be described later, using the specimens preformed through the above process, the conventional sample powder It is possible to secure an additional space of 30 to 60% in the mold compared to the method used immediately, so that at least two edge rings can be manufactured per one process, and the inflow of impurities can be effectively prevented during hot press sintering. There is an effect of minimizing a separate post-processing process such as wire cutting after sintering.

Meanwhile, the prepress of this step may be performed by first preparing a mold for prepress, filling and leveling the granulated powder of the sample prepared in step a in the mold, and then pressing one axis (Fig. 1).

Specifically, the process is to fill the granulated powder in the mold and then fill the uniform sample through flattening of the upper surface, but only by the weight of the powder without partial pressure or removal, and then push the unnecessary upper part. can be done in this way.

Next, a pre-molded specimen is prepared by uniaxially pressing the filled granulated powder, and the pressing condition may be performed by pressing within a range of 50 to 150 kg/cm ² .

Next, the ceramic specimen is treated with Cold Isostatic Pressing (CIP) to remove density variation of the specimen (step c).

The cold isostatic pressing is performed to effectively prevent distortion of the specimen during hot pressing sintering to be described later by removing foreign matter from the specimen and minimizing the density deviation of the specimen with respect to the preformed specimen obtained through step b. it could be

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

Meanwhile, foreign matter on the preformed specimen is removed through the above steps, 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 specimens using a carbon sheet member to prevent bonding between specimens, and the laminated form will be described later by hot 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 hot-pressed sintered (step d).

On the other hand, sintering molding methods for obtaining a dense sintered body reaching theoretical density using ceramics as a main material include atmospheric pressure sintering, reactive sintering, recrystallization, oxide bonding, and hot pressure sintering.

In the present invention, a hot press sintering method capable of achieving densification close to theoretical density at a lower temperature than normal pressure sintering can be used to manufacture a sintered body without sintering aid or with a minimum amount of non-oxide-based ceramics.

Specifically, the specimen obtained in step c is loaded into a mold provided in a furnace, and at a temperature in the range of 1900 to 2100 ° C and a pressure of 50 kgf / cm ² to 220 kgf / cm ² , more specifically at a temperature of 2100 ° C And 186 kgf / cm ² It is possible to form a sintered body by uniaxially pressing under a pressure condition.

On the other hand, the mold used in the step is a configuration for manufacturing a sintered body, for example, a graphite material may be used, and it may be performed in a mold of a multi-layered structure capable of simultaneously sintering a plurality of specimens.

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 at a predetermined interval inside the outer sleeve. At least one mold unit including a sleeve, a core disposed in the inner sleeve, an upper punch formed at an upper end of the spaced apart space between the outer sleeve and the inner sleeve, and a lower punch formed at a lower end of the spaced space. ), and bases respectively formed on the top and bottom of the one or more mold units.

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

On the other hand, the sleeve has a trapezoidal cross-sectional shape and 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 replace. . On the other hand, the core is provided to fix the inner sleeve, and has a feature of reducing defects resulting from a thermal expansion difference due to cooling of the sintered body. The core according to an embodiment of the present invention may have a 4- or 6-part structure. In this case, since demolding of the inner core becomes easy, it is possible to effectively prevent breakage of the sintered body during demolding.

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

Meanwhile, a hole may be formed inside the core, and when the hole is formed inside the core, defects of the sintered body are minimized by reducing shrinkage stress during cooling after sintering the sintered body.

Meanwhile, a carbon sheet (not shown) may be additionally provided as a component of the mold, and the carbon sheet is provided to facilitate demolding, prevent contamination, and match thermal expansion, and specifically has a thickness of 0.5 mm to 5 mm. A range of thicknesses of carbon sheet may be used.

Plasma resistant edging

On the other hand, the sintered 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 due to these characteristics, the plasma resistance and corrosion resistance have this very excellent effect.

6 shows a method for manufacturing a ceramic composite according to the present invention.

Referring to FIG. 6 , an embodiment of the method for manufacturing a ceramic composite according to the present invention includes preparing granulated powder (S601), preparing a ceramic specimen (S602), and laminating the specimen in a mold (S602). S603), a semi-sintering step (S604), an impregnation step (S605), and a re-sintering step (S606).

Specifically, in the step of preparing granulated powder (S601), one or more samples selected from the group consisting of silicon carbide (SiC), boron carbide (B ₄ C) and silicon nitride (Si ₃ N ₄ ) may be pretreated. there is.

When the granulated powder is prepared, a step (S602) of manufacturing the granulated powder into a ceramic specimen by pre-forming the granulated powder through a prepress may be performed. The ceramic specimen prepared in this way may be stacked in a mold (S603).

In the method for manufacturing a ceramic composite according to the present invention, a step (S604) of firing and semi-sintering at least a portion of the laminated specimens may be performed.

That is, the specimens may be fired so that 50% to 90% of the specimens are sintered, rather than performing complete sintering after the specimens are laminated.

In the case of hot pressing in the semi-sintering step, a porous body is not sufficiently formed, and the sintering density of only the surface of the semi-sintered object may increase. Therefore, in order to increase the success rate of impregnation after the semi-sintering step, it is appropriate to perform firing.

In one example, the pre-sintering step may be performed by firing the specimen such that 50% to 90% of the specimen is sintered.

Meanwhile, in a state in which at least a part of the specimen is sintered, a step of impregnating the specimen with a predetermined additive (S605) may be performed.

Finally, a step of hot-pressing and re-sintering the specimen impregnated with the additive (S606) may be performed. At this time, the re-sintering is preferably performed at a temperature lower than the temperature at which complete sintering is performed.

In one example, the impregnated additive may be made of the same material as the specimen. More preferably, the additive may include fine particles of the semi-sintered specimen.

In another example, the impregnated additive may include at least one of an oxide for a resistor, a boron compound for a conductor, and a conductive metal. In particular, the additive is at least one of silicon carbide (SiC), titanium diboride (TiB ₂ ), ceramic oxide (ZrO ₂ ), yttrium (Y ₂ O ₃ ), titanium (Ti), iron (Fe) and aluminum (Al). may contain one.

In another embodiment, the semi-sintering step may further include removing a predetermined amount of boron oxide from the surface of the sintered body.

According to the plasma-resistant edge ring manufacturing method of the present invention described above, since it is possible to manufacture edge rings using a plurality of pre-formed specimens whose uniformity is secured through the pre-press process, sample powder during hot press sintering It is possible to secure 30 to 60% of additional space in the mold compared to the case of using directly, making it possible to manufacture at least twice as many edge rings per process, to prevent the inflow of impurities, and also to wire after sintering. 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 pressure treatment on the specimen preformed by the prepress process, foreign matter is removed from the specimen, and the density deviation of the specimen is minimized to minimize the hot It is possible to effectively prevent the distortion of the specimen during the pressure sintering process, and accordingly, the sintered density of the edge ring manufactured through the hot pressure sintering process 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 thereby the scope of the invention is not limited in any sense.

Example 1

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, and then mix with a liquid ball mill and pre-treat by spray drying to obtain granulated boron carbide powder got

Next, the granulated boron carbide powder was filled into a prepared prepress mold, leveled, and uniaxially pressed at 80 kg/cm2 to prepare a boron carbide specimen, which was laminated in three layers.

Next, the laminated boron carbide specimen was pressurized for 5 minutes under a condition of 1500 bar using a CIP device to perform a cold isostatic pressing process.

Next, the specimen obtained through the above step was loaded into a mold for hot pressing, and uniaxially pressed under conditions of a temperature of 2100° C. and a pressure of 186 kgf/cm2 to form a sintered body. The sintered body can be used as an edge ring product constituting a covering assembly in a plasma device without a separate post-processing process.

Comparative Example 1

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

After filling the inside of the mold with the granulated powder prepared in Example 1, it was charged into the mold for hot pressing, and uniaxially pressed under conditions of a temperature of 2100 ° C and a pressure of 186 kgf / cm2 to form a sintered body.

Example 1 Comparative Example 1 thickness deviation 0.1 0.5 density deviation 0.2% 0.5%

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) preparing a ceramic specimen by pre-molding the granulated powder through a prepress;
c) laminating the specimen in a mold;
d) firing and semi-sintering at least a portion of the laminated specimens;
e) impregnating a predetermined additive into the specimen while at least a part of the specimen is sintered; and
f) hot-pressing and re-sintering the specimen impregnated with the additive;
The additives are
Ceramic composite manufacturing method, characterized in that composed of the same material as the specimen.
delete delete delete According to claim 1,
The semi-sintering of step d is a ceramic composite manufacturing method, characterized in that carried out by firing the specimen so that the sintered density of the specimen is 50% to 90%.
delete delete

Images