KR20220067400A - High-Resistance Silicon Carbide Product Forming Method and High-Resistance Silicon Carbide Product - Google Patents

Abstract

The present invention relates to a method for forming high-resistance silicon carbide parts and the high-resistance silicon carbide parts. According to the present invention, a method includes: a preparation process for disposing a base part in a chamber; an exhaust process of exhausting a fluid in the chamber; and a deposition process of depositing a silicon carbide layer by injecting a reaction gas containing hydrogen and alkylsilane into the chamber using monoatomic molecules as a transport gas. Thus, a technique for obtaining high-resistance silicon carbide parts is disclosed.

Description

High-Resistance Silicon Carbide Product Forming Method and High-Resistance Silicon Carbide Product

The present invention relates to a method for forming a high-resistance silicon carbide component and a high-resistance silicon carbide component, and more particularly, to a method for forming a high-resistance silicon carbide component capable of improving high resistivity, durability, and corrosion resistance to plasma and high-resistance silicon carbide It's about parts.

Various types of ceramic products are applied during the semiconductor manufacturing process. Among them, silicon carbide is superior to other ceramic materials in physical properties such as strength and hardness and thermal properties such as thermal conductivity and thermal expansion coefficient. It is widely applied to manufacturing process equipment such as plasma etching process. In particular, in the plasma etching process, silicon carbide components are often used in the focus ring positioned at the edge of the silicon wafer and the upper electrode positioned above the silicon wafer. When the plasma dry etching process is performed, other silicon carbide components in the chamber are also etched in addition to the silicon wafer to be plasma etched in the chamber, so that even silicon carbide products with excellent mechanical, thermal, and chemical resistance are damaged.

These silicon carbide parts are expensive materials, but after a certain period of use, the silicon carbide parts etched by plasma must be replaced with new silicon carbide products, and the replaced silicon carbide parts are in a damaged state, so they are disposed of. This has become a factor in the increase in the cost of the semiconductor manufacturing process, and there has been a demand for a technology capable of improving durability and plasma corrosion resistance while increasing the resistivity of silicon carbide components.

Laid-Open Patent Publication No. 10-2010-0133910

The present invention provides a method for forming a high-resistance silicon carbide component and a high-resistance silicon carbide component having a high specific resistance value and improved durability and corrosion resistance to plasma.

A method of forming a high-resistance silicon carbide component according to an embodiment of the present invention includes a preparation process for disposing a base portion in a chamber; an exhaust process for exhausting the fluid in the chamber; and a deposition process of depositing a silicon carbide layer by injecting a reaction gas containing hydrogen and alkylsilane into the chamber using monoatomic molecules as a transport gas.

Here, a heat treatment process of heat-treating the base part at a temperature between 1300 degrees Celsius and 1600 degrees Celsius in a reducing atmosphere; further includes.

Here, the base part is a silicon carbide base material or a graphite jig.

Here, the silicon carbide layer deposited in the deposition process has a needle-like crystal structure corresponding to an aspect ratio of 1:1.5 to 1:5.

Here, the silicon carbide layer deposited in the deposition process has a specific resistance value of 400 to 3000 Ω·cm.

Here, the deposition process is performed by atmospheric pressure chemical vapor deposition.

Here, the base portion is a silicon carbide base material, and the size of the crystal structure in the silicon carbide layer deposited in the deposition process is formed smaller than the size of the crystal structure of the silicon carbide base material.

Here, the heat treatment process and the deposition process are continuously performed in-situ in the chamber.

Here, the deposition process is carried out at a temperature of 1300 degrees Celsius to 1400 degrees Celsius.

Here, in the deposition process, the deposition of the silicon carbide layer proceeds at a deposition rate of 0.03 to 0.20 mm/h.

Here, the volume flow ratio of hydrogen and alkylsilane contained in the reaction gas in the deposition process is 8% to 12%.

Here, the SLM (standard liter per min) ratio between the alkylsilane injected in the deposition process and the monoatomic molecule is 35: 1 to 60: 1.

Here, the alkylsilane is methyltrichlorosilane (MTS), and the monoatomic molecule is argon.

A high-resistance silicon carbide component according to an embodiment of the present invention includes a silicon carbide layer having a needle-like crystal structure corresponding to an aspect ratio of 1:1.15 to 1:5.

Here, the distribution ratio of the needle-shaped crystal structure per unit area in the silicon carbide layer is 75% or more.

Here, the silicon carbide layer has a bending strength between 300 MPa to 500 MPa.

Here, the silicon carbide layer has a specific resistance value of 400 to 3000 Ω·cm.

Here, the width of the crystal structure of the silicon carbide layer corresponds to between 2 micrometers and 4 micrometers.

According to the method for forming a high-resistance silicon carbide component and a high-resistance silicon carbide component according to an embodiment of the present invention, the silicon carbide component that cannot be used in the semiconductor process and is discarded is used as the base because the surface is damaged by plasma, etc. and it is difficult to reuse it as it is. Therefore, since it can be reused through the method for forming high-resistance silicon carbide parts according to the present invention, the cost of disposing of silicon carbide parts and purchasing new ones can be reduced. The use cycle is extended, which helps to improve the convenience of process equipment management. It is also sufficiently possible to form a high-resistance silicon carbide component using a graphite jig as a base portion.

In addition, since the electrical properties of the silicon carbide layer deposited according to the method for forming high-resistance silicon carbide parts of the present invention exhibit high resistivity, it can be applied to semiconductor process equipment requiring silicon carbide parts with high resistivity, and the deposited Since the needle-like crystal structure formed in the silicon carbide layer has a high density, the bending strength is increased, and there is an effect of helping to suppress the shortening of the lifespan due to the increase in the bending strength.

In addition, since the silicon carbide layer deposited according to the method of forming a high-resistance silicon carbide component of the present invention can realize a high deposition rate, the time required to deposit the target deposition thickness of the silicon carbide layer on the silicon carbide base material is significantly reduced. Since it is reduced, it is possible to produce a large amount of silicon carbide parts because the regeneration process for a higher quantity of high-resistance silicon carbide base material is possible. Therefore, there is also an effect that helps to improve the production efficiency of high-resistance silicon carbide parts.

1 is a flowchart schematically illustrating a method for forming a high-resistance silicon carbide component according to an embodiment of the present invention.
2 is a partial cross-sectional view schematically illustrating a high-resistance silicon carbide component formed by depositing a silicon carbide layer on a base according to a method for forming a high-resistance silicon carbide according to an embodiment of the present invention.
3 is an SEM image diagram schematically illustrating a portion of a silicon carbide layer of a high-resistance silicon carbide component formed according to an embodiment of the present invention.
4 is an SEM image diagram schematically showing a portion of a silicon carbide layer of a silicon carbide component formed according to the prior art.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and the scope of the invention to those of ordinary skill in the art completely It is provided to inform you. In the description, the same reference numerals are assigned to the same components, and the drawings may be partially exaggerated in size to accurately describe the embodiments of the present invention, and the same reference numerals refer to the same elements in the drawings.

1 is a flowchart schematically illustrating a method of forming a high-resistance silicon carbide component according to an embodiment of the present invention.

Referring to FIG. 1 , a method for forming a high-resistance silicon carbide component according to an embodiment of the present invention includes a preparation process for arranging a base part in a chamber (S110); an exhaust process of evacuating the fluid in the chamber (S120); a heat treatment process of heat-treating the silicon carbide base material at a temperature between 1300 degrees Celsius and 1600 degrees Celsius in a reducing atmosphere (S130); and a deposition process of depositing a silicon carbide layer having a specific resistance higher than a reference value on the silicon carbide base material by injecting a reaction gas containing hydrogen and alkylsilane into the chamber using monoatomic molecules as a transport gas after the exhaust process (S140) ); includes.

First, in the preparation process (S110), the base part is disposed in the chamber. Here, the base portion is preferably made of silicon carbide or graphite. As an example of such a base part, a silicon carbide base material or a graphite jig may be mentioned. The use of a silicon carbide base material made of silicon carbide as a base portion will be described as an example. Of course, a graphite jig, which is a base part made of graphite, can also be used as a base part for forming a high-resistance silicon carbide layer.

The silicon carbide base material has a poor surface roughness due to an oxide film formed on the surface or the surface is etched by about 1 mm to 10 mm through an etching process by a plasma processing device during a semiconductor process, or it may contain by-products from etching. As an example of the silicon carbide base material, a silicon carbide focus ring used in a chemical vapor deposition apparatus or the like may be mentioned.

The evacuation process ( S120 ) is a process of evacuating the fluid in the chamber to form a vacuum atmosphere below a predetermined vacuum degree.

In the evacuation process (S120), it is preferable because it helps to create a reducing atmosphere in the heat treatment process (S130) by evacuating a fluid such as gas in the chamber to the outside to form a vacuum atmosphere below a predetermined degree of vacuum.

In this exhaust process (S120), the predetermined degree of vacuum may be, for example, 10 Torr. To make the inside of the chamber less than 10 Torr, which is a vacuum state, pumping is performed to exhaust the fluid in the chamber. Through this exhaust process (S120), a gas such as nitrogen or oxygen is also exhausted to the outside of the chamber.

Subsequently, the heat treatment process (S130) is a process of high-temperature heat treatment at a temperature between 1300 degrees Celsius and 1600 degrees Celsius in a reducing atmosphere with respect to the silicon carbide base material disposed in the preparation process. For reference, when the base part is made of graphite, for example, in the case of a graphite jig, the heat treatment process (S130) may be omitted.

The heat treatment process ( S130 ) may include a first high temperature heat treatment process and a second high temperature heat treatment process performed at a lower temperature than the first high temperature heat treatment process.

In the heat treatment process ( S130 ), a pumping operation is performed to make the inside of the chamber less than 10 Torr, which is a vacuum state, and a heat treatment process may be performed by applying heat to the silicon carbide base material.

A reducing gas is injected into the chamber to create a reducing atmosphere, and the temperature in the chamber is heated to a high temperature to remove defects and oxide films on the damaged silicon carbide base material surface. In a high-temperature environment, the reducing gas reacts with an oxide film formed on the surface of the damaged silicon carbide base material, and can be removed by reducing the oxide film.

In a high-temperature environment, silicon with reduced oxide film or silicon and carbon present in the damaged silicon carbide base material may mutually diffuse. The surface is rearranged by interdiffusion of silicon and carbon in the reduced oxide silicon or damaged silicon carbide base material.

In addition, by realignment, the roughness of the surface of the silicon carbide base material is relieved and planarized, and by-products such as etching in a high-temperature environment can be removed, and organic materials, etc. are removed from the damaged silicon carbide base material during heating to a high temperature.

This high-temperature heat treatment process may be performed at a temperature of 1300 ℃ to 1600 ℃. Here, the reducing atmosphere may be formed by injecting a heat treatment gas containing hydrogen (H ₂ ) into the chamber.

Heat may be applied to the chamber so that the temperature in the chamber becomes a high temperature of 1300°C to 1600°C. The oxide film (SiO ₂ , etc.) on the surface of the damaged silicon carbide base material reacts with hydrogen gas, a reducing gas, etc. in a high-temperature environment to reduce the oxide film, and silicon and carbon, etc. present in the reduced silicon or damaged silicon carbide base material are rearranged Accordingly, the crystalline structure formed in the needle shape in the silicon carbide layer deposited in the deposition process (S140) to be described later has a high density and is a basis for increasing the specific resistance.

When the temperature in the chamber is less than 1300°C during the heat treatment, the organic matter existing on the surface of the damaged silicon carbide base material can be removed, but the reduction reaction of the oxide film reduced at high temperature does not occur easily because sufficient energy is not supplied, so the oxide film is not easily removed Also, since silicon and carbon present in the silicon with reduced oxide film or the damaged silicon carbide base material do not diffuse well, realignment does not occur, making it difficult to improve the flatness of the silicon carbide surface.

When the temperature in the chamber exceeds 1600° C. during heat treatment, the silicon carbide layer as well as the oxide film at high temperature are also affected by thermal decomposition or thermal shock, which may adversely affect the silicon carbide base material.

On the other hand, by injecting a reducing atmosphere, such as hydrogen (H ₂ ) gas into the chamber, the pressure in the chamber may be formed in a range of 50 Torr to 760 Torr, which is a low vacuum state or atmospheric pressure state. By forming a relatively high pressure, a large amount of reducing gas can be present, thereby making it easier to react with the oxide film on the surface of the damaged silicon carbide base material. In addition, since the pressure is similar to a process of performing a plurality of high-temperature heat treatment or a process of depositing a silicon carbide layer, which will be described later, the above process may be continuously performed.

In the embodiment according to the present invention, a pumping operation is performed to make the inside of the chamber less than 10 Torr, which is a vacuum state, and heat is applied to increase the temperature according to desired conditions. In order to create a reducing atmosphere, hydrogen (H ₂ ) gas is injected step by step. The pressure in the chamber is set to 50 Torr to 760 Torr, and after maintaining that state for a while, the gas in the chamber is pumped out for the holding time for each condition to remove impurities mixed in the gas.

In the process of the first high-temperature heat treatment, the inside of the chamber can be made into a vacuum state through the pumping operation, and then the temperature is raised to a high temperature, and hydrogen gas, which is a reducing gas, is injected to proceed with the high-temperature heat treatment process. Defects existing on the surface, the oxide film (SiO ₂ ) is removed or the surface roughness is improved, and silicon and carbon present in the silicon carbide with the reduced oxide film or the damaged silicon carbide are rearranged.

After the first high-temperature heat treatment process, the second high-temperature heat treatment process can be continuously performed without performing the pumping operation, and the process is performed at a lower temperature than the first high-temperature heat treatment process. This is to further stabilize the damaged silicon carbide base material that has undergone the first high-temperature heat treatment process.

The second high-temperature heat treatment process may be performed with the same conditions such as pressure as in the first high-temperature heat treatment process, but the heat treatment temperature is, for example, about 1400 degrees Celsius. In order to raise the pressure lowered through the pumping operation in the first high-temperature heat treatment process, hydrogen gas is additionally injected, and the temperature can be adjusted by heating or cooling to set the desired temperature.

By proceeding with the second high-temperature heat treatment process, the silicon and carbon present in the silicon and carbon with the reduced oxide film or the damaged silicon carbide base material realigned during the first high-temperature heat treatment process are realigned for a sufficient time to further flatten the surface roughness. Defects that can be and could not be eliminated can be additionally removed. In addition, the oxide film (SiO ₂ ), which has not been removed, can be further removed by a reduction reaction with hydrogen gas, which is a reducing gas, so that it can be in a more stable state than the silicon carbide base material that has undergone only the first high-temperature heat treatment process.

In addition, by performing the second high-temperature heat treatment process, silicon carbide can be rapidly deposited by chemical vapor deposition (CVD) in the deposition process S140. A silicon carbide base material that has been more stably heat treated can be obtained through a sufficient realignment time for the second high-temperature heat treatment process.

This high-temperature heat treatment process may be performed multiple times, and may include a first high-temperature heat treatment process or a second high-temperature heat treatment process. The process of high-temperature heat treatment a plurality of times may be performed by lowering the temperature of the corresponding number of times than the temperature of the previous round. During the high-temperature heat treatment process, a vacuum of 10 Torr or less is created through pumping, and at the end of the high-temperature heat treatment process, pumping is performed again to discharge the vaporized contaminants to the outside. If necessary, the pumping operation may be performed even during the high-temperature heat treatment process. In addition, the pumping process may be performed multiple times according to the high-temperature heat treatment process.

When the high-temperature heat treatment process is performed multiple times, the pumping operation to create a vacuum in the chamber through the pumping operation performed according to each number of times proceeds only in the first high-temperature heat treatment process, and the process of high-temperature heat treatment for the remaining number of times is the same as the previous time. A high-temperature heat treatment process may be performed immediately after the pumping operation is performed.

In this way, the temperature is not lowered too much, so that the immediately next high-temperature heat treatment process may be continuously performed, and the deposition process to be described later may be continuously performed. On the other hand, starting from the second high-temperature heat treatment process, a plurality of high-temperature heat treatment processes may be performed directly without performing a pumping operation between the plurality of high-temperature heat treatment processes, or may proceed to a deposition process (S140) to be described later.

If the high-temperature heat treatment process is insufficient because the high-temperature heat treatment process is not fully performed, the roughness of the surface of the silicon carbide base material cannot be improved. If the silicon carbide layer is deposited while the surface of the silicon carbide base material is rough, when plasma processing is subsequently performed in a plasma processing device, the plasma may come into contact with the rough part of the surface and cause arcing. It is desirable to improve the roughness of the surface through the process.

It is preferable to perform an exhaust process after the heat treatment process (S130).

For reference, even if the base part is a graphite jig, it is preferable to undergo an exhaust process.

The evacuation process is a process of evacuating the fluid around the silicon carbide base material heat-treated in the chamber to form a vacuum atmosphere below a predetermined vacuum degree. In the exhaust process, if a fluid such as gas in the chamber is exhausted to the outside to form a vacuum atmosphere below a predetermined vacuum degree, silicon carbide can be deposited in the deposition process (S140) without the influence of impurities other than the reaction gas and the transport gas, so it is preferable. .

In this exhaust process, the predetermined degree of vacuum may be, for example, 10 Torr. To make the inside of the chamber less than 10 Torr, which is a vacuum state, pumping is performed to exhaust the fluid around the silicon carbide base material, and then the deposition process proceeds.

By forming a vacuum atmosphere in the exhaust process, it is possible to suppress the effect of nitrogen when the silicon carbide layer is deposited in the deposition process ( S140 ). When the silicon carbide layer is deposited, nitrogen in the chamber is a factor that reduces the resistivity of the silicon carbide layer.

Therefore, it is preferable to suppress the influence of nitrogen on the silicon carbide layer deposited in the deposition process ( S140 ) by lowering the partial pressure of nitrogen as much as possible in the chamber. Therefore, since a vacuum atmosphere is formed in the exhaust process before the deposition process (S140), and monoatomic molecules are used as a transport gas in the deposition process (S140), the partial pressure of nitrogen can be greatly reduced in the deposition process (S140) and converted to nitrogen. It is possible to suppress the decrease in resistivity caused by

The deposition process (S140) is a process of depositing a silicon carbide layer having a specific resistance higher than a reference value on the base portion by injecting a reaction gas containing hydrogen and alkylsilane into the chamber using monoatomic molecules as a transport gas.

Here, as the base part made of silicon carbide or graphite as mentioned above, a silicon carbide base material or a graphite jig is possible.

This deposition process ( S140 ) may be performed by atmospheric pressure chemical vapor deposition. As mentioned above, in the evacuation process (S130), a vacuum atmosphere is formed in the chamber at a predetermined degree of vacuum, and hydrogen and alkylsilane are injected as reaction gases using monoatomic molecules as transport gases, so that deposition is performed at atmospheric pressure. Therefore, the partial pressure of nitrogen is suppressed to a negligible level. Accordingly, a decrease in resistivity of the hydrocarbon layer due to nitrogen is suppressed, so that a hydrocarbon layer having a high resistivity can be deposited.

The deposition process (S140) is preferably performed at a temperature of 1300 degrees Celsius to 1400 degrees Celsius. More preferably, the process may be performed at a temperature between 1340 degrees Celsius and 1390 degrees Celsius.

In addition, the deposition of the silicon carbide layer may proceed at a deposition rate of 0.03 to 0.20 mm/h. The deposition rate may vary depending on equipment and process conditions, but in general, the thickness of the silicon carbide layer deposited per hour is 0.03 to 0.20 mm/h, more preferably 0.05 to 0.15 mm/Hr, and deposited to a thickness of 5 mm. It takes about 33 to 100 hours of deposition time. In this way, the time it takes to reach the thickness of the silicon carbide layer to be deposited can be shortened compared to the prior art.

In addition, it is preferable that the heat treatment process (S120) and the deposition process (S140) are continuously performed in-situ in the chamber. When the heat treatment process (S120) and the deposition process (S140) are continuously performed in-situ in the chamber, it is preferable because the process time is shortened compared to the case where the heat treatment process (S120) and the deposition process (S140) are not performed in-situ.

The following Table 1 is a table showing the characteristics of the high-resistance silicon carbide part regenerated according to the deposition conditions in each embodiment in the method for forming the high-resistance silicon carbide part according to the embodiment of the present invention. A silicon carbide base material was used as the base part.

Condition α = Q _H2 /Q _MTS MTS H ₂
(SLM) Ar
(SLM) N ₂
(SLM) deposition temperature
(℃) resistivity
(Ωㅇcm) crystal structure
(diameter x length) Bending strength (MPa) Example 1 7.7% 26 200 0 0.5 1450 1-5 high density structure
(3x10um) 440 Example 2 7.7% 26 200 One 0 1450 50-120 Low density structure (3x20um) 270 Example 3 8.0% 24 190 One 0 1410 140-750 240 Example 4 7.5% 20 150 0.5 0 1400 280~650 280 Example 5 8.5% 20 170 0.5 0 1380 420-1220 high density structure
(3x10um) 340 Example 6 10.6% 16 170 0.3 0 1350 480-2750 420 Example 7 9.4% 16 150 0.25 0 1390 490-1650 470

According to Example 1 in Table 1, a silicon carbide layer having a general resistivity value is formed. Examples 2, 3, and 4 are examples of forming the silicon carbide layer under the condition that the deposition temperature is 1400 degrees Celsius or more and the volume flow rate ratio α of hydrogen and methyltrichlorosilane is less than 8%. Although the density of the crystal structure and the bending strength are high, the specific resistance is relatively low due to the effect of nitrogen.

In Examples 2, 3, and 4, the needle-like crystal structure formed in the silicon carbide layer is formed to be relatively large, and the density of the crystal structure is formed to be low, that is, the density. Therefore, the bending strength does not exceed 300 MPa, and there is a limit to having a high specific resistance value on average.

In Examples 5 to 7 of Table 1 according to the method for forming a high-resistance silicon carbide part according to the present invention, the partial pressure of nitrogen in the chamber is virtually 0 within the error range, and is a negligible level, and the volume of hydrogen and methyltrichlorosilane The flow rate ratio α is 8% to 12%, the standard liter per min (SLM) ratio between the alkylsilane and the monoatomic molecule is 35:1 to 60:1, and deposition between 1340 degrees Celsius and 1390 degrees Celsius An example in which a silicon carbide part was formed at a temperature is shown.

As shown in Examples 5 to 7 of Table 1, the specific resistance value has a specific resistance value exceeding 400 Ω·cm, which is a reference value that can be regarded as a high resistance. That is, it has a specific resistance value between 400 and 3000 Ω·cm. In addition, the needle-like crystal structure formed on the silicon carbide layer forms a dense form. That is, the size of the crystal structure of the silicon carbide layer deposited in the deposition process (S140) is formed smaller than the size of the crystal structure of the silicon carbide base material.

As the needle-like crystal structure is formed smaller than the size of the crystal structure of the silicon carbide base material, it shows high density and the bending strength is increased to 300 MPa or more. In this way, the deposition process (S140) of the method for forming a high-resistance silicon carbide component according to an embodiment of the present invention capable of obtaining a high-resistance silicon carbide component will be described in more detail.

As shown in Table 1, the volume flow rate ratio of hydrogen and alkylsilane contained in the reaction gas in the deposition process (S140) is preferably 8% to 12%. In addition, it is preferable that a standard liter per min (SLM) ratio between the alkylsilane injected in the deposition process ( S140 ) and the monoatomic molecules is 35:1 to 60:1.

Here, it is preferable that the alkylsilane is methyltrichlorosilane (MTS), and the monoatomic molecule is argon. The volume flow rate ratio of hydrogen and methyltrichlorosilane gas is important in forming a high resistance of the CVD silicon carbide layer. The volume flow rate ratio α is α = Q _H2 /Q _MTS , and when the volume flow rate ratio α is low, the deposition rate is fast, but it is difficult to increase the resistivity value and the mechanical properties are deteriorated.

As can be seen from the examples of the present invention, the volume flow rate α of hydrogen and methyltrichlorosilane is preferably 8% to 12%, more preferably within the range of 8.5% to 10.6% do.

As such, under the condition that the volume flow rate ratio α of hydrogen and methyltrichlorosilane is within the range of 8% to 12% or more preferably 8.5% to 10.6%, a hydrocarbon layer having a high resistance, that is, a high specific resistance value, is deposited. can

Here, high resistance, that is, high specific resistance, refers to a resistance value of 400 Ω·cm or more, which is a reference value, and more specifically, it is preferable that a specific resistance value falls between 400 Ω·cm and 3000 Ω·cm.

As mentioned above, it is preferable to use a monoatomic molecular gas as the transport gas, and more preferably use argon (Ar) as the transport gas. Too much argon makes it difficult to implement a high resistivity value of the silicon carbide component, and may adversely affect the needle-like crystalline structure formed in the silicon carbide layer, thereby reducing bending strength. Therefore, it is preferable to use a small amount of argon as the transport gas.

Therefore, as can be seen from the deposition conditions and characteristics shown in Table 1 above, it is preferable that the ratio of SLM (standard liter per min) between methyltrichlorosilane and argon is 35:1 to 60:1. . In this way, when the SLM ratio between methyltrichlorosilane and argon is between 35:1 and 60:1 together with the deposition conditions described above, high-resistance silicon carbide parts with high specific resistance and increased durability and bending strength are manufactured. be able to get

2 is a partial cross-sectional view schematically illustrating a high-resistance silicon carbide component formed by depositing a silicon carbide layer on a base according to a method for forming a high-resistance silicon carbide according to an embodiment of the present invention.

As shown in FIG. 2 , the silicon carbide layer 120 is deposited on the surface of the base 110 through the above preparation process ( S110 ) to the deposition process ( S140 ) to obtain a high-resistance silicon carbide component. . However, as mentioned above, when the base part 110 is a graphite jig, the heat treatment process may be omitted. And if necessary, it is also sufficiently possible to remove the base portion 110 made of silicon carbide or graphite from the high-resistance silicon carbide layer 120 after the deposition process (S140).

Here, the description will be continued with further reference to FIGS. 3 and 4 .

3 is a SEM image schematically showing a portion of a silicon carbide layer obtained in Example 7 of Table 1 as a method for forming a high resistance silicon carbide component according to an embodiment of the present invention, and FIG. 4 is a conventional general condition according to an embodiment of the present invention. As that, it is a SEM image schematically showing the silicon carbide layer portion of the silicon carbide component obtained in Example 5 in Table 1.

The dense form of the silicon carbide layer 120 can be divided into the size and density of the CVD silicon carbide needle-like crystal structure. As shown in FIG. 4 , the low density structure has a large needle-like crystalline structure and a low degree of tissue density. As shown in FIG. 3 , the high density structure has a small needle-like crystal structure, , it can be seen that the needle-like crystal structure is densely distributed over the entire area.

That is, as shown in FIG. 3, the needle-like crystal structure formed in the high-resistance silicon carbide layer formed according to the embodiment of the present invention is in the silicon carbide layer of the silicon carbide component according to the embodiment of the conventional general condition shown in FIG. It can be seen that it is densely formed compared to the formed needle-like crystal structure. In addition, as shown in FIG. 3 , it can be seen that the aspect ratio of the needle-shaped crystal structure formed in the silicon carbide layer deposited according to the embodiment of the present invention corresponds to between 1:1.5 and 1:5.

And it is preferable that the distribution ratio of the needle-shaped crystal structure per unit area in the silicon carbide layer 120 is 75% or more. As such, the high-resistance silicon carbide component 100 formed with a high density of needle-like crystal structure exhibits a bending strength of 300 MPa or more, and more specifically, a high bending strength of 340 MPa to 470 MPa.

On the other hand, the needle-like crystal structure in the silicon carbide layer deposited according to an embodiment of the conventional general condition has an aspect ratio of 1:7 or more, and the average size of the needle-like crystal structure is 3 micrometers in diameter and a length Represents a size of 20 micrometers. And it can be seen that the density of the needle-like crystal structure is significantly lower than that of the needle-like crystal structure in the silicon carbide layer 120 deposited according to the embodiment of the present invention referenced in FIG. 3 , and that of the needle-like crystal structure per unit area It indicates a distribution with a distribution ratio of 60% or less. And, CVD silicon carbide, in which needle-like crystal structure is formed with such a low density, exhibits a characteristic of low bending strength of 280 MPa or less.

As described above, in the deposition process (S140), the silicon carbide layer 120 deposited on the base part 110, such as a silicon carbide base material or a graphite jig, has a needle-like aspect ratio of 1:1.5 to 1:5. It is desirable to have a crystal structure of (針狀). Here, the width of the crystal structure corresponds to between 2 micrometers and 4 micrometers, and more preferably has a size of about 3 micrometers.

A high-resistance silicon carbide component can be obtained according to the method for forming a high-resistance silicon carbide component according to an embodiment of the present invention as described above.

In addition, in the method for forming a high-resistance silicon carbide component according to an embodiment of the present invention as described above, the sequence of each process is not limited to a specific sequence, and the sequence of each process is changed or repeated as needed. It is possible.

2, the high-resistance silicon carbide component 100 according to the embodiment of the present invention is deposited on the base portion and has a needle-like aspect ratio of 1:1.15 to 1:5. and a silicon carbide layer having a crystalline structure and having a resistivity higher than a reference value. Such a high-resistance silicon carbide component 100 can be obtained by the high-resistance silicon carbide component forming method according to the embodiment of the present invention as described above. Here, the base part 110 may be the silicon carbide base material or the graphite jig as mentioned above, and the base part may be removed from the silicon carbide layer if necessary.

That is, the high-resistance silicon carbide component 100 has a specific resistance value exceeding 400 Ω·cm, which is a reference value for which the specific resistance value can be regarded as high resistance. Preferably, it has a specific resistance value between 400 and 3000 Ω·cm. In addition, the needle-like crystal structure formed on the silicon carbide layer 120 forms a dense form.

As mentioned above, when the base portion is a silicon carbide base material, the size of the crystal structure in the silicon carbide layer 120 is formed smaller than the size of the crystal structure of the silicon carbide base material 110 . As the needle-like crystal structure is formed smaller than the size of the crystal structure of the silicon carbide base material, it shows high density and the bending strength is increased to 300 MPa or more. In addition, the specific resistance value is also high.

As described above, in the high-resistance silicon carbide component 100 , the distribution ratio of the needle-shaped crystal structure per unit area in the silicon carbide layer 120 is preferably 75% or more. It is more preferable if the distribution ratio of the needle-like crystal structure per unit area is 80% or more. In addition, it is preferable that the silicon carbide layer 120 of the high-resistance silicon carbide component 100 has a bending strength between 300 MPa and 500 MPa. As described above, the silicon carbide layer 120 of the high-resistance silicon carbide component 100 has a specific resistance value of 400 to 3000 Ω·cm.

In addition, it is preferable that the width of the needle-shaped crystal structure in the silicon carbide layer 120 of the high resistance silicon carbide component 100 corresponds to between 2 micrometers and 4 micrometers. The length of the needle-like crystal structure is preferably within 10 micrometers.

As such, when the size of the needle-like crystal structure is formed small in the silicon carbide layer 120, bending strength and density are increased, and it is preferable because it has a high resistivity value.

Alternatively, it can be said that the size of the crystal structure of the silicon carbide layer 120 is preferably formed smaller than the size of the crystal structure of the silicon carbide base material 110 . In other words, it may be said that the size of the grains of the silicon carbide layer 120 is preferably formed smaller than the size of the grains of the silicon carbide base material 110 . As the size of the crystal structure of the silicon carbide layer 120 is formed smaller than the size of the crystal structure of the silicon carbide base material 110 , durability and deposition rate may be increased.

As the size of the crystal structure of the silicon carbide layer 120 is formed smaller than the size of the crystal structure of the silicon carbide base material 110, the crystal structure in the silicon carbide layer 120 is compared to the crystal structure of the silicon carbide base material 100. It shows a relatively high density, and as mentioned above, the specific resistance is increased and the bending strength is increased.

When the size of the crystal structure or the grain size of the silicon carbide layer 120 is formed larger than the size of the crystal structure or the grain size of the silicon carbide base material 110, durability or plasma resistance is lowered even with a high specific resistance value. A problem arises. However, according to the high-resistance silicon carbide component forming method and high-resistance silicon carbide component of the present invention, the silicon carbide component 100 has a high specific resistance value while having a small crystal structure and high density, so durability and plasma resistance and bending strength are increased.

For reference, before proceeding with the preparation process (S110) of disposing the silicon carbide base material into the chamber, the process of mechanical cleaning and chemical cleaning may be performed by examining the surface state of the damaged silicon carbide base material. Mechanical cleaning can remove foreign substances by processing 0.2 mm to 1 mm of the upper and side surfaces of the silicon carbide base material using mechanical processing equipment such as a machining center (MCT), a rotary grinder, and a plane grinder.

Chemical cleaning can remove foreign substances and metals from the surface in advance by putting the silicon carbide base material in a water bath containing an acid solution such as sulfuric acid, hydrofluoric acid, nitric acid or salt and soaking it for several minutes to several hours. Chemical cleaning includes a cleaning method using ozone or hydrofluoric acid and a RCA (Radio Corporation of America) cleaning method. The cleaning method using ozone or hydrofluoric acid is a method of immersing the silicon carbide base material in ozone or hydrofluoric acid contained in a bath for 10 seconds to 1 minute. Ozone is preferred because it acts the same as hydrogen peroxide as a stronger oxidizing agent than hydrogen peroxide and does not form harmful reactants when decomposed. Hydrofluoric acid is effective because it can remove the oxide film on the surface of the silicon carbide base material, and it can also remove fine particles and metal contaminants at the same time in the process of removing the oxide film.

In addition, after depositing a silicon carbide layer by chemical vapor deposition, measuring the thickness of the coated silicon carbide layer, mechanical polishing is performed to a certain thickness to satisfy the standard for thickness, and final cleaning is carried out to ship. may additionally be included.

The silicon carbide base material used as the base portion in the present invention may be a high-resistance silicon carbide component regenerated by the method for forming a high-resistance silicon carbide component as described above. The high-resistance silicon carbide component may also be a focus ring provided at the edge of the wafer in a plasma processing apparatus.

A plasma processing apparatus used during a semiconductor manufacturing process injects and ionizes a gaseous etching gas into a chamber, and accelerates the ionized gas to the surface layer of the wafer to chemically remove the wafer surface layer. The lower electrode that fixes the silicon wafer used in the plasma processing apparatus, the focus ring provided at the edge of the silicon wafer, and the upper electrode positioned on the upper part of the silicon wafer are made of silicon carbide, which is more mechanically and thermally compared to other ceramic materials. , excellent chemical resistance. However, during the process of chemically removing the surface layer of the wafer in the plasma processing apparatus, the silicon carbide parts made of silicon carbide were also damaged, and in the end, they could not be used for a long time and had to be discarded. The completed silicon carbide part can be reused through the method for forming the high-resistance silicon carbide part as described above. In particular, among the silicon carbide components, the focus ring positioned at the edge of the silicon wafer and serving to fix the wafer may be a focus ring regenerated by the method of forming a high-resistance silicon carbide component of the present invention. The focus ring may serve to prevent the diffusion of plasma in the plasma processing apparatus where plasma is formed and to concentrate the plasma around the wafer on which the square processing is performed.

As described above, according to the method for forming a high-resistance silicon carbide component and a high-resistance silicon carbide component according to an embodiment of the present invention, the silicon carbide cannot be used in a semiconductor process and is discarded because the surface is damaged by plasma, etc. Since parts can be reused through the method of forming high-resistance silicon carbide parts of the present invention, the cost of disposing of silicon carbide parts and purchasing new ones is reduced, and the overall use cycle of silicon carbide parts is extended through regeneration, so process equipment management It has the advantage of helping to increase the convenience of In addition, even when a graphite jig is used as the base portion, a high-resistance silicon carbide component can be formed.

In addition, since the electrical properties of the silicon carbide layer deposited according to the method for forming high-resistance silicon carbide parts of the present invention exhibit high resistivity, it can be applied to semiconductor process equipment requiring silicon carbide parts having high resistivity, and the deposited Since the needle-like crystal structure formed in the silicon carbide layer achieves a high density, the bending strength is increased, and there is also an advantage that helps to suppress the shortening of the lifespan due to the increase in the bending strength.

In addition, since the silicon carbide layer deposited according to the method of forming a high-resistance silicon carbide component of the present invention can realize a high deposition rate, the time required to deposit the target deposition thickness of the silicon carbide layer on the silicon carbide base material is significantly reduced. can be reduced Therefore, it is possible to produce a large amount of high-resistance silicon carbide parts because a larger number of high-resistance silicon carbide parts can be formed using the silicon carbide base material 110 or a base such as a graphite jig. Therefore, there is also an advantage of helping to improve the production efficiency of high-resistance silicon carbide parts.

Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described embodiments, and common knowledge in the field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims Those having a will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the technical protection scope of the present invention should be defined by the following claims.

100: silicon carbide part 110: base part
120: silicon carbide layer

Claims (15)

a preparation process for placing the base part in the chamber;
an exhaust process for exhausting the fluid in the chamber; and
A method of forming a high-resistance silicon carbide component comprising: a deposition process of depositing a silicon carbide layer by injecting a reaction gas containing hydrogen and alkylsilane into the chamber using monoatomic molecules as a transport gas.
The method of claim 1,
The method of forming a high-resistance silicon carbide component, wherein the base portion is made of silicon carbide or graphite.
The method of claim 1,
The silicon carbide layer deposited in the deposition process,
A method for forming a high-resistance silicon carbide part having a needle-like crystalline structure corresponding to an aspect ratio of a crystalline structure between 1:1.5 and 1:5.
The method of claim 1,
The silicon carbide layer deposited in the deposition process,
A method of forming a high-resistance silicon carbide component having a resistivity value corresponding to between 400 and 3000 Ω·cm.
The method of claim 1,
The deposition process is a high-resistance silicon carbide component forming method performed by atmospheric pressure chemical vapor deposition.
The method of claim 1,
The deposition process is
A method of forming a high-resistance silicon carbide part proceeding at a temperature of 1300 degrees Celsius to 1400 degrees Celsius.
The method of claim 1,
In the deposition process, the deposition of the silicon carbide layer is a high-resistance silicon carbide component forming method that proceeds at a deposition rate of 0.03 to 0.20 mm/h.
The method of claim 1,
A method of forming a high-resistance silicon carbide component in which the volume flow ratio of hydrogen and alkylsilane contained in the reaction gas in the deposition process is 8% to 12%.
9. The method of claim 8,
A method of forming a high-resistance silicon carbide component in which a standard liter per min (SLM) ratio between the alkylsilane injected in the deposition process and the monoatomic molecules is 35: 1 to 60: 1.
10. The method of claim 9,
The alkylsilane is methyltrichlorosilane (MTS), and the monoatomic molecule is argon.
A high-resistance silicon carbide component comprising a; a silicon carbide layer having a needle-like crystalline structure corresponding to an aspect ratio of a crystal structure between 1:1.15 and 1:5.
12. The method of claim 11,
A high-resistance silicon carbide component in which the distribution ratio of the needle-like crystal structure per unit area in the silicon carbide layer is 75% or more.
12. The method of claim 11,
The silicon carbide layer is a high-resistance silicon carbide component having a bending strength between 300 MPa to 500 MPa.
12. The method of claim 11,
The silicon carbide layer is a high-resistance silicon carbide component having a resistivity value corresponding to between 400 and 3000 Ω·cm.
12. The method of claim 11,
A high-resistance silicon carbide component in which the width of the crystal structure of the silicon carbide layer is between 2 micrometers and 4 micrometers.

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