JP5421460B2 - Electrostatic chuck and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electrostatic chuck and a manufacturing method thereof, and more particularly to an electrostatic chuck for attracting and supporting a substrate and a manufacturing method thereof in a semiconductor manufacturing apparatus using plasma.

Among semiconductor manufacturing apparatuses, a plasma processing apparatus processes a semiconductor substrate by converting a process gas into a plasma state while the semiconductor substrate is fixed to a substrate support in a chamber. An example of the substrate support is an electrostatic chuck that uses electrostatic force to fix the semiconductor substrate.

The electrostatic chuck is provided such that an electrode layer is embedded between dielectric layers, and a semiconductor substrate is electrostatically attracted and fixed by an electrostatic force formed on the dielectric layer by applying a voltage to the electrode layer. . Here, in the case of an electrostatic chuck used in a plasma processing apparatus, a dielectric is formed using a thermal spray coating layer for preventing etching by a plasma process gas.

Generally, a thermal spray coating layer used as a dielectric layer in an electrostatic chuck of a plasma processing apparatus is a ceramic thermal spray coating powder containing yttrium oxide (Y ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), or the like. Is formed by a thermal spray coating process.

As described above, the thermal spray coating layer using the ceramic thermal spray coating powder has a crystal structure, and the thermal spray coating layer having the crystal structure has an advantage that the dielectric constant is relatively good.

However, in the case of a thermal spray coating layer having a crystal structure, leakage current is generated due to the disadvantage that relatively many pores exist and volume resistance is low, and the occurrence of arcing due to leakage current is a problem. In order to improve this, a method has been developed to increase the volume resistance through a sealing process that fills the pores contained in the thermal spray coating layer having a crystal structure. There was a problem that the adsorption function deteriorated.

Further, recently, the increase in the size of the substrate is progressing rapidly, and the voltage applied to the electrode layer in order to adsorb a large area substrate is increasing from a low voltage to a high voltage. However, the higher the voltage is, the more likely the dielectric breakdown phenomenon occurs due to the occurrence of cracks due to the difference in thermal expansion coefficient between the substrate and the thermal spray coating layer, and it is difficult to increase the electrostatic adsorption function. There is.

Therefore, there is a demand for an electrostatic chuck having a dielectric layer with an increased volume resistance to prevent leakage current while maintaining a dielectric constant necessary for forming electrostatic force.

Therefore, one problem to be solved by the present invention is to provide an electrostatic chuck that can suppress the occurrence of arcing due to leakage current by increasing the volume resistance without reducing the dielectric constant necessary for forming electrostatic force. .

Another object of the present invention is to provide a method for manufacturing the electrostatic chuck.

In order to achieve the object of the present invention, an electrostatic chuck according to an embodiment of the present invention includes a base, an amorphous first insulating layer formed on the base, and the first insulating layer. And an electrostatic force generating electrode layer formed on the electrode layer and a dielectric layer formed on the electrode layer.

Here, in the electrostatic chuck according to an embodiment, the dielectric layer includes an amorphous first dielectric layer formed on the electrode layer, and a crystalline second dielectric layer formed on the first dielectric layer. A dielectric layer can be included.

In the electrostatic chuck according to another embodiment, the first dielectric layer may have a thickness of 100 μm to 300 μm, and the second dielectric layer may have a thickness of 200 μm to 400 μm.

In the electrostatic chuck according to another embodiment, the first dielectric layer has a porosity of 0.5% to 2%.
The porosity of the second dielectric layer may be 3% to 7%.

In the electrostatic chuck according to another embodiment, the first dielectric layer has a surface roughness (Ra) of 4 μm to 8 μm, and the second dielectric layer has a surface roughness (Ra) of 3 μm to 5 μm. Can do.

In the electrostatic chuck according to another embodiment, the first dielectric layer and the second dielectric layer may have a hardness of 650 Hv or more and an adhesive strength of 14 Mpa or more.

In the electrostatic chuck according to another embodiment, the total volume resistance of the first dielectric layer and the second dielectric layer may be 10 ¹⁴ to 10 ¹⁵ Ω · cm.

In an electrostatic chuck according to another embodiment, the electrode layer is formed to be embedded by the first dielectric layer, and the first dielectric layer is formed to be embedded by the second dielectric layer. be able to.

In the electrostatic chuck according to another embodiment, the first insulating layer may have a thickness of 400 μm to 600 μm.

The electrostatic chuck according to another embodiment may further include a crystalline second insulating layer formed between the base and the electrode layer. The first insulating layer may have a thickness of 100 μm to 300 μm, and the second insulating layer may have a thickness of 200 μm to 400 μm.

In order to achieve the object of the present invention, an electrostatic chuck according to an embodiment of the present invention includes a base, an insulating layer formed on the base, and an electrostatic force generation formed on the insulating layer. An electrode layer; an amorphous first dielectric layer formed on the electrode layer; and a crystalline second dielectric layer formed on the first dielectric layer.

In order to achieve the other objects of the present invention, a method of manufacturing an electrostatic chuck according to an embodiment of the present invention includes a step of preparing a base, and an amorphous first insulating layer is formed on the base. Forming an electrostatic force generating electrode layer on the first insulating layer; and forming a dielectric layer on the electrode layer.

In this case, in the electrostatic chuck manufacturing method according to an embodiment, the step of forming the dielectric layer includes the step of forming an amorphous first dielectric layer on the electrode layer and the step of forming the dielectric layer on the first dielectric layer. Forming a crystalline second dielectric layer.

In the electrostatic chuck manufacturing method according to another embodiment, the first dielectric layer is formed so as to surround the electrode layer, and the second dielectric layer is the first insulating layer, the first dielectric layer, and the substrate. Can be formed to wrap.

In the electrostatic chuck manufacturing method according to another embodiment, the first insulating layer, the first dielectric layer, and the second dielectric layer may be formed by an atmospheric plasma spraying process, a high-speed oxygen-fuel spraying process, a vacuum plasma spraying process, or Or any one of the kinetic injection steps.

In the electrostatic chuck manufacturing method according to another embodiment, the first insulating layer and the first dielectric layer and the second dielectric layer are individually or group-wise or collectively used as a sealing material. A sealing process may be further included.

In an electrostatic chuck manufacturing method according to another embodiment, a crystal is formed on the first insulating layer before the step of forming the electrode layer or on the base body before the step of forming the first insulating layer. The method may further include forming a quality second insulating layer.

The second insulating layer may be formed by any one of an atmospheric plasma spraying process, a high-speed oxygen-fuel spraying process, a vacuum plasma spraying process, or a kinetic injection process. And a step of sealing the first insulating layer and the second insulating layer and the first dielectric layer and the second dielectric layer individually or in groups or collectively using a sealing material. Further can be included.

  In order to achieve another object of the present invention, a method of manufacturing an electrostatic chuck according to an embodiment of the present invention includes a step of preparing a base, a step of forming a first insulating layer on the base, Forming an electrostatic force generating electrode layer on the first insulating layer; forming an amorphous first dielectric layer on the electrode layer; and a crystalline second dielectric on the first dielectric layer. Forming a layer.

In the electrostatic chuck according to the present invention configured as described above, since the dielectric layer is formed of a multilayer structure including an amorphous thermal spray coating layer and a crystalline thermal spray coating layer, it is suitable for forming an electrostatic force. Since the volume resistance increases while having a dielectric constant, the leakage current is suppressed to suppress the occurrence of arcing, the electrostatic attraction force is improved, and the electrical characteristics are improved.

In addition, by providing a buffer layer in the terminal connection portion for applying a voltage to the electrode layer, it is possible to improve crack defects that frequently occur in the terminal connection portion due to thermal stress.

Accordingly, the maintenance cost of the electrostatic chuck can be reduced, the process efficiency can be improved by improving the function of the electrostatic chuck, and the life of the electrostatic chuck can be increased by improving the durability.

It is the schematic which shows the structure of the electrostatic chuck by one Embodiment of this invention. FIG. 2 is a schematic diagram illustrating an embodiment of the connector illustrated in FIG. 1. FIG. 6 is a schematic view showing still another embodiment of the connector shown in FIG. 1. It is the schematic which shows the structure of the electrostatic chuck which concerns on other embodiment of this invention. 3 is a graph showing insulation resistance according to a voltage applied to an electrode layer in an electrostatic chuck according to the present invention and a conventional electrostatic chuck. 6 is a graph showing leakage current and cooling gas supply amount according to usage time of the electrostatic chuck according to the present invention and the conventional electrostatic chuck. 4 is a graph showing an etching rate after an etching process using an electrostatic chuck according to the present invention. It is the graph which illustrated the etching rate after the etching process using the conventional electrostatic chuck. FIG. 2 is a photograph for explaining a first thermal spray coating powder used for forming a thermal spray coating layer having an amorphous structure illustrated in FIG. 1. FIG. It is process drawing for demonstrating the manufacturing method of the powder for 1st thermal spray coating shown in FIG. It is process drawing for demonstrating the formation method of the 1st slurry composition illustrated in FIG. It is process drawing for demonstrating the formation method of the 2nd slurry composition illustrated in FIG. 11 is a view for explaining the binding of yttrium oxide and aluminum oxide in the method for forming the mixed slurry composition illustrated in FIG. 10. It is process drawing for demonstrating the electrostatic chuck manufacturing method by one Embodiment of this invention.

Hereinafter, an electrostatic chuck and a method for manufacturing the same according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are herein described in detail. However, this should not be construed as limiting the invention to the particular forms disclosed, but should be understood to include all modifications, equivalents or alternatives that fall within the spirit and scope of the invention. Similar reference numerals have been used for similar components while describing the drawings. In the accompanying drawings, the size of the structure is shown enlarged from the actual size for the sake of clarity of the present invention. Although terms such as first and second are used to describe various components, these components are not limited by such terms. These terms are used to distinguish one component from another. For example, the first component can be named as the second component without departing from the scope of the present invention, and the second component can be named as the first component as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular form includes the plural form unless the context clearly dictates otherwise. In this specification, terms such as “comprising” or “having” shall specify that there is a feature, number, step, action, component, part, or combination thereof, as described in the specification. The existence or addition of one or more other features or numbers, steps, operations, components, parts or combinations thereof is not excluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, are generally understood by those of ordinary skill in the art to which this invention belongs. Have the same meaning. It should be understood that the same terms defined in commonly used dictionaries have meanings that are consistent with the meanings in the context of the related art, and are not ideal or excessive unless explicitly defined herein. Should not be interpreted as a formal meaning.

The electrostatic chuck includes a unipolar type having one electrode and a bipolar type having two electrodes. Here, a unipolar type electrostatic chuck having one electrode will be described.

FIG. 1 is a schematic view showing a configuration of an electrostatic chuck according to an embodiment of the present invention.

Referring to FIG. 1, an electrostatic chuck 100 according to an embodiment of the present invention includes a base 110, a first insulating layer 120, an electrode layer 140, a first dielectric layer 150, a second dielectric layer 160, and a connector 170. Including.

In particular, in the electrostatic chuck 100, the first insulating layer 120 and the first dielectric layer 150 are thermal spray coating layers having an amorphous structure, and the second dielectric layer 160 is a thermal spray coating layer having a crystal structure. That is, the dielectric layer of the electrostatic chuck 100 is composed of multiple layers including an amorphous thermal spray coating layer and a crystalline thermal spray coating layer, and a dielectric constant necessary for forming electrostatic force is secured through the multilayer structure. At the same time, the electrical characteristics are improved by ensuring a high volume resistance. In addition, the insulating layer for insulating the substrate 110 and the electrode layer 140 is composed of an amorphous spray coating layer, so that the insulating characteristics are improved by the high volume resistance characteristics of the amorphous spray coating layer. The

The substrate 110 has a flat plate shape or a cylinder shape. The substrate 110 generally has a size corresponding to an object to be adsorbed (for example, a substrate). That is, the substrate 110 may have the same size as the substrate for manufacturing a semiconductor device or a flat display device, or may be larger than the size of the substrate. As an example, the substrate 110 can be made of metal. An example of the metal may include aluminum (Al). As another example, the substrate 110 may include a metal coating layer on its surface.

The first insulating layer 120 is formed on the substrate 110. For example, the first insulating layer 120 may be formed on a partial region of the upper surface of the base 110. The first insulating layer 120 has an amorphous structure and is obtained by a thermal spray coating process using the first thermal spray coating powder. That is, the first thermal spray coating powder is a thermal spray coating powder for forming an amorphous thermal spray coating layer. For example, the first thermal spray coating powder may include coarse particles including yttrium oxide and aluminum oxide and having an average particle diameter of 20 um to 60 um. Specifically, the first thermal spray coating powder may be composed of coarse particles obtained from a mixed slurry composition of a first slurry composition and a second slurry composition. Here, the first slurry composition includes a yttrium oxide particle having a diameter of 0.01 um to 2 um, a first dispersant that uniformly disperses the yttrium oxide particle, and a binding force between the yttrium oxide particles. 1 binder and an extra first solvent. The second slurry composition includes aluminum oxide particles having a diameter of 0.5 um to 2 um, a second dispersant that uniformly disperses the aluminum oxide particles, and a second binder that provides a binding force between the aluminum oxide particles. And an extra second solvent. In the mixed slurry composition, the yttrium oxide of the first slurry composition and the aluminum oxide of the second slurry composition have a weight ratio of 1: 0.4-1. The first thermal spray coating powder will be described in more detail below.

The first insulating layer 120 has a thickness of 400 um to 600 um. The first insulating layer 120 insulates the base 110 and the electrode layer 140. However, when the thickness of the first insulating layer 120 is less than 400 μm, the withstand voltage characteristic is deteriorated even if it has a volume resistance for insulation. This is undesirable because the insulation between the electrode layer 140 and the substrate 110 is lowered. The first insulating layer 120 has a high volume resistance due to the amorphous structure. For example, the first insulating layer 120 has a volume resistance of about 10 ¹³ Ω · cm. In addition, the first insulating layer 120 may be subjected to a sealing process for filling pores included in the thermal spray coating layer in a post-processing process, and the volume resistance of the first insulating layer 120 is about 10 through the sealing process. It increases to ¹⁴ to 10 ¹⁵ Ω · cm. In addition, since the first insulating layer 120 has an amorphous structure, the space inside the coating layer can be minimized and has a low porosity. The first insulating layer 120 has a porosity of 2% or less, and preferably 1% or less. Specifically, the first insulating layer 120 is about 0.5% to 2%.
And preferably has a porosity of about 0.5% to 1%. The first insulating layer 12
0 has a surface roughness (Ra) of 4 um to 8 um in order to ensure an adhesive strength of a certain level or higher, and has an adhesive strength of 14 Mpa or more through this. The first insulating layer 120 has a hardness of 650 Hv or more.

A bonding layer 115 may be provided between the base 110 and the first insulating layer 120. The bonding layer 115 serves to bond the base 110 and the first insulating layer 120 together. The bonding layer 115 has a thermal expansion coefficient that is about the middle between the thermal expansion coefficient of the base 110 and the first insulating layer 120, and is formed between the base 110 and the first insulating layer 120 having different thermal expansion coefficients. Play a buffer role. The bonding layer 115 includes a metal alloy, and examples of the metal alloy include a nickel-aluminum alloy. The bonding layer 115 may have a thickness of 30 μm to 50 μm and a porosity of about 5% or less.

The electrode layer 140 is formed on the first insulating layer 120. For example, the electrode layer 140 may be formed in a partial region of the upper surface of the first insulating layer 120. The electrode layer 140 is provided for generating electrostatic force. The electrode layer 140 generates an electrostatic force on the upper surface of the second dielectric layer 160 using the first dielectric layer 150 and the second dielectric layer 160 as dielectrics, and is seated on the second dielectric layer 160 by the electrostatic force. The substrate to be electrostatically adsorbed is fixed and maintained. The electrode layer 140 is made of a conductive material. An example of the conductive material is tungsten. As an example, the electrode layer 140 may be formed by a spray coating process. In contrast, the electrode layer 140 can be formed using screen printing techniques. The electrode layer 140 has a thickness of about 30 μm to 50 μm. When the thickness of the electrode layer 140 is less than 30 μm, the resistance value increases due to the porosity and other defects in the electrode layer 140, and a phenomenon in which the electrostatic adsorption force decreases due to the increase in the resistance value occurs. So undesirable. If the thickness of the electrode layer 140 exceeds 50 μm, an overcurrent is generated and arcing occurs, which is not desirable. Accordingly, the electrode layer 140 preferably has a thickness of about 30 μm to 50 μm.

The electrode layer 140 receives a high voltage from the outside to form an electrostatic force, and the high voltage is applied through the connector 170. The connector 170 is connected to the electrode layer 140 through the base 110 and the first insulating layer 120.

FIG. 2 is a schematic view showing an embodiment of the connector shown in FIG.

Referring to FIG. 2, the connector 170 according to an embodiment includes a terminal 171, an insulating member 172, and a buffer layer 173.

The terminal 171 penetrates the base 110 and the first insulating layer 120 and is electrically connected to the electrode layer 140, and transmits a high voltage supplied from an external power source (not shown) to the electrode layer 140. To play a role. Accordingly, the base 110 and the first insulating layer 120 are provided with through holes for penetrating the terminals 171. The terminal 171 is made of a conductive material. For example, the terminal 172 can be made of a conductive material such as tungsten, molybdenum, or titanium.

The insulating member 172 is provided to insulate the terminal 171. Therefore, the insulating member 172
Is formed so as to enclose the terminal 171. For example, the insulating member 172 is formed between the terminal 171 and the base 110 and between the terminal 171 and the first insulating layer 120. The insulating member 172 can also be formed between the terminal 171 and the electrode layer 140 excluding a part of the tip of the terminal 171 in contact with the electrode layer 140. The insulating member 172 can be formed of, for example, a ceramic sintered body. Since the ceramic sintered body has few pores, there is an advantage that the insulating property can be maximized. Here, the insulating member 172 may be formed to a thickness of about 2000 um, and 0.1 um to 2 u in order to reduce surface resistance and reduce arcing.
It can be formed to have a surface roughness (Ra) of m.

Thermal stress (for example, thermal stress due to plasma temperature) is applied to the electrostatic chuck 100 while a process (for example, plasma process) is performed on the substrate. Specifically, the electrostatic chuck 100 undergoes thermal expansion due to heat generated during the process, but the thermal stress differs in the degree of thermal expansion of the base 110, the first insulating layer 120, and the insulating member 172. Will occur. Such thermal stress becomes maximum at the end of the contact surface between the insulating member 172 and the base 110, the end of the contact surface of the first insulating layer 120, and the like. Further, the thermal stress is propagated to the first insulating layer 120 having a relatively low strength to generate cracks, and further grows to the first dielectric layer 150 and the second dielectric layer 160 side to increase the lifetime of the electrostatic chuck 100. It becomes a factor to shorten.

A buffer layer 173 is provided to minimize damage due to such thermal stress.

The buffer layer 173 is formed so as to wrap around a partial region of the insulating member 172. For example, the buffer layer 173 is formed on at least a part of the contact surface between the insulating member 172 and the base 110, the contact surface between the insulating member 172 and the first insulating layer 120, and the contact surface between the insulating member 172 and the electrode layer 140. Can do. The buffer layer 173 may include ceramic. Examples of the ceramic include Al ₂ O ₃ , Y ₂ O ₃ , Al ₂ O ₃ / Y ₂ O ₃ , ZrO ₂ , AlC, TiN, AlN, TiC, _{MgO, CaO, CeO 2, TiO} 2, BxCy, BN, SiO 2, SiC, YAG, mention may be made of Mullite, the AlF ₃ and the like. At this time, these ceramics can be used alone or in combination. As an example, the buffer layer 173 can be formed using a thermal spray coating process.

The buffer layer 173 has a thickness of 100 um to 250 um, and preferably has a thickness of 150 um to 200 um. When the thickness of the buffer layer 173 exceeds 250 μm, it is not desirable because cracks may be generated by generating pores in the buffer layer 173, and when the thickness of the buffer layer 173 is less than 100 μm, This is not desirable because it can no longer serve as a buffer. Further, the buffer layer 173 is desirably formed to have a surface roughness (Ra) of 0.1 μm to 2 μm in order to reduce the occurrence of arcing by reducing the surface resistance.

The buffer layer 173 serves to absorb (buffer) thermal stress generated due to the temperature rise of the electrostatic chuck 100 during the process. For example, thermal stress generated when the electrostatic chuck 100 receives heat and the base 110 expands is absorbed by the buffer layer 173 without being directly transmitted to the insulating member 172.

In the present embodiment, in order to maximize the buffer effect of the thermal stress by the buffer layer 173, the porosity of the buffer layer 173 is the same as that of the base 110, the first insulating layer 120, the first dielectric layer 150, and the second dielectric layer 160. Desirably, the porosity is equal to or higher than the porosity. For example, the buffer layer 173 may have a porosity of 2% to 10%, and preferably has a porosity of 2% to 7%. When the porosity of the buffer layer 173 exceeds 10%, the pores inside the buffer layer 173 increase and the strength is lowered. Further, the buffer layer 173 itself may be dropped. Buffer layer 1 if rate is less than 2%
Since a crack may occur in 73, it is not desirable.

In addition, the edge portion of the buffer layer 173 is preferably formed to have a round shape or a chamfer shape that is not sharp. This is because if the edge portion of the buffer layer 173 has a sharp shape, stress is concentrated on that portion and the probability of occurrence of cracks can be increased.

FIG. 3 is a schematic view showing another embodiment of the connector shown in FIG.

Here, the connector 170 illustrated in FIG. 3 is very similar to the connector 170 described above with reference to FIG. 2 except for differences in form. Therefore, for convenience of explanation, it should be understood that the differences will be briefly described mainly, and the parts not described will be the same as those shown in FIG.

Referring to FIG. 3, the connector 170 according to another embodiment includes a terminal 177, an insulating member 178, and a buffer layer 179.

The terminal 177 penetrates the base 110 and the first insulating layer 120 and is electrically connected to the electrode layer 140, and serves to transmit a high voltage from an external power source (not shown) to the electrode layer 140.

The insulating member 178 is formed between the base 110 and the terminal 177 and serves to insulate the base 110 from the terminal. The insulating member 178 is formed with respect to the base 110 region. That is, the insulating member 178 is formed between the terminal 177 and the base 110.

The buffer layer 179 is provided to buffer thermal stress. The buffer layer 179 includes a first buffer layer 179a and a second buffer layer 179b.

The first buffer layer 179 a is formed to wrap around a partial region of the upper step portion of the insulating member 178 and the upper step portion of the terminal 177 exposed from the insulating member 178. For example, the first buffer layer 179a is formed on a part of the contact surface between the base 110 and the insulating member 178, the contact surface between the insulating member 178 and the first insulating layer 120, and the contact surface between the terminal 177 and the first insulating layer 120. Can be formed. Here, as mentioned above, although the first buffer layer 179a is formed so as to enclose part of the upper portion of the insulating member 178 and the terminal 177, a crack can occur. That is, if the first buffer layer 179a cannot completely absorb the thermal stress, a crack may be generated at the end of the contact surface between the base 110 and the insulating member 178. However, the crack grows and the first dielectric layer 150 is grown. And can be propagated to the second dielectric layer 160. Accordingly, the second buffer layer 179b is provided to prevent the generated crack from being propagated to the first dielectric layer 150 and the second dielectric layer 160 even though the first buffer layer 179a is formed. .

The second buffer layer 179b is formed near the upper portion of the insulating member 178. For example, the second buffer layer 179 b may be formed between the insulating member 178 and the first insulating layer 120 and in a partial region of the contact surface between the base 110 and the first insulating layer 120. Here, the second buffer layer 179 b is formed between the insulating member 178 and the first insulating layer 120 substantially between the first buffer layer 179 a and the first insulating layer 120. The second buffer layer 179b has substantially the same characteristics as the first buffer layer 179a except for the formation position, such as material, thickness, and surface roughness.

As mentioned above, the first buffer layer 179a and the second buffer layer 179b are formed around the contact surface between the base 110 and the insulating member 178, which is the point where the largest thermal stress is generated. Since absorption is performed in two stages, the occurrence of cracks can be prevented more effectively. Therefore, shortening of the life of the electrostatic chuck 100 can be improved. Meanwhile, although the buffer layer 179 has been described as including the first buffer layer 179a and the second buffer layer 179b, in other embodiments, the second buffer layer 179b may be omitted.

In the present embodiment, the base 110 has an inclined surface corresponding to the position where the terminal 177 and the insulating member 178 penetrate. Due to the inclined surface of the base 110, the density of the A region of the first insulating layer 120 may be relatively lower than the density of the B region on the base 110 excluding the inclined surface. On the other hand, since the thickness of the A region is larger than the thickness of the B region, current leakage through the pores included in the first insulating layer 120 in the A region can be reduced. Therefore, the occurrence of arcing between the substrate 110 and the electrode layer 140 can be reduced. In addition, since the thickness of the region A is relatively large, the occurrence of cracks in the first insulating layer 120 at the interface between the base 110 and the insulating member 178 can be prevented. Accordingly, the occurrence of arcing between the substrate 110 and the electrode layer 140 through the crack can be reduced.

The electrode layer 140 is preferably formed such that the upper surface of the electrode layer 140 in the upper region of the terminal 177 is lower than the upper surface of the electrode layer 140 in the upper region of the first insulating layer 120. Through this, the thickness of the first dielectric layer 150 and the second dielectric layer 160 formed in the C region above the terminal 177 is the thickness of the first dielectric layer 150 and the second dielectric layer 160 formed in the remaining D region. It is desirable to form it thicker than the thickness. This is to prevent a discharge phenomenon between the electrode layer 140 and the substrate that is seated and supported on the second dielectric layer 160 even when a high voltage power source is applied to the electrode layer 140 through the terminal 177. .

Referring back to FIG. 1, the first dielectric layer 150 is formed on the electrode layer 140. The first dielectric layer 150 is formed to enclose the electrode layer 140 so that the electrode layer 140 is embedded. For example, the first dielectric layer 150 may be formed on the remaining region of the upper surface of the first insulating layer 120 where the electrode layer 140 is not formed and the upper surface of the electrode layer 140. The first dielectric layer 150 is obtained by a thermal spray coating process using the first thermal spray coating powder. Therefore, the first dielectric layer 150 also has an amorphous structure. That is, the first thermal spray coating powder used to form the first dielectric layer 150 is the same as the first thermal spray coating powder used to form the first insulating layer 120.

The first dielectric layer 150 has a thickness of 100 um to 300 um. Since the first dielectric layer 150 has an amorphous structure, the space inside the coating layer can be minimized, and thus has a low porosity. The first dielectric layer 150 has a porosity of 2% or less, and preferably 1% or less. Specifically, the first dielectric layer 150 has a porosity of about 0.5% to 2%, and preferably has a porosity of about 0.5% to 1%. The first dielectric layer 150 has a surface roughness (Ra) of 4 μm to 8 μm in order to ensure the adhesive strength, and has an adhesive strength of 14 Mpa or more through this. The first dielectric layer 150 has a hardness of 650 Hv or higher.

The second dielectric layer 160 is formed on the first dielectric layer 150, and a substrate is attached to an upper surface thereof. For example, the second dielectric layer 160 may be formed on the upper surface of the first dielectric layer 150. In addition, the second dielectric layer 160 may be formed on the first insulating layer 120, the first dielectric layer 150, and the entire exposed surface of the substrate 110. That is, the second dielectric layer 160 completely covers the exposed surfaces of the base 110, the first insulating layer 120, and the first dielectric layer 150, thereby preventing the member from being damaged. . The second dielectric layer 160 is obtained by a thermal spray coating process using the second thermal spray coating powder. Here, the second thermal spray coating powder is a thermal spray coating powder for forming a crystalline coating layer. For example, the second thermal spray coating powder may include a ceramic. Examples of the ceramic include Al ₂ O ₃ , Y ₂ O ₃ , Al ₂ O ₃ / Y ₂ O ₃ , ZrO ₂ , AlC, TiN, AlN, TiC, MgO, CaO, CeO ₂ , TiO ₂ , BxCy, BN, SiO ₂ , SiC, YAG, Mullite, AlF _{3 and the} like can be mentioned. These can be used alone or in combination.

The second dielectric layer 160 has a thickness of 200 um to 400 um. The second dielectric layer 160 has a higher porosity than the first dielectric layer 150 by having a crystal structure. Accordingly, the second dielectric layer 160 has a porosity of 3% to 7%. The second dielectric layer 160 has a surface roughness (Ra) of 3 μm to 5 μm in order to ensure the adhesive strength between the coating layers, and has an adhesive strength of 14 Mpa or more through this. The second dielectric layer 160 has a hardness of 650 Hv or more.

In the present embodiment, the thicknesses of the first dielectric layer 150 and the second dielectric layer 160 of the dielectric layer have ranges of 100 μm to 300 μm and 200 μm to 400 μm, respectively. The thicknesses of the first dielectric layer 150 and the second dielectric layer 160 have the mentioned ranges due to dielectric constant, volume resistance (for example, insulation resistance), electrostatic adsorption force, and the like. When the thickness of the dielectric layer, that is, when the total thickness of the first dielectric layer 150 and the second dielectric layer 160 exceeds 500 μm, the distance between the electrode layer 140 and the substrate (for example, the adsorption target) becomes long and static. Electroadsorptive power can be reduced, which is undesirable. Accordingly, it is desirable that the total thickness of the first dielectric layer 150 and the second dielectric layer 160 does not exceed 500 μm. In addition, the dielectric constant of the dielectric layer is greatly influenced by the second dielectric layer 160 having a crystal structure, but when the thickness of the second dielectric layer 160 is less than 200 μm, a sufficient dielectric constant necessary for forming electrostatic force is obtained. Is not desirable because it is not secured. Further, the volume resistance is greatly influenced by the first dielectric layer 150 having an amorphous structure. However, when the thickness of the first dielectric layer 150 is less than 100 μm, the volume resistance is low, which is not desirable. Accordingly, the first dielectric layer 150 and the second dielectric layer 160 have a total thickness not exceeding 500 μm, the first dielectric layer 150 has a thickness of 100 μm or more, and the second dielectric layer 160 has a thickness of 200 μm or more. It is desirable to have. As a result, the first dielectric layer 150 and the second dielectric layer 160 have a thickness of 100 μm to 300 μm, and the thickness of the second dielectric layer 160 is It is desirable to have 200 um to 400 um.

As described above, in the electrostatic chuck 100 according to the present embodiment, the dielectric layer is composed of multiple layers including the crystalline thermal spray coating layer and the amorphous thermal spray coating layer. It has the effect of increasing the volume resistance without a decrease. For example, in general, a crystalline thermal spray coating layer has a volume resistance of about 10 ⁹ to 10 ¹¹ Ω · cm, while an amorphous thermal spray coating layer has a volume resistance of about 10 ¹³ Ω · cm. That is, the second dielectric layer 160 has a volume resistance of about 10 ⁹ to 10 ¹¹ Ω · cm, and the first dielectric layer 150 has a volume resistance of about 10 ¹³ Ω · cm. Furthermore, the total volume resistance of the first dielectric layer 150 and the second dielectric layer 160 acting as dielectrics has a volume resistance of about 10 ¹³ Ω · cm. As a result, when the dielectric layer is composed of multiple layers of an amorphous layer and a crystalline layer, the volume resistance increases while maintaining the dielectric constant as in the conventional case. Accordingly, the insulation resistance is increased, and the insulation characteristics are increased through the increase of the insulation resistance. Therefore, a dielectric layer with improved electrical characteristics can be implemented. Further, in the electrostatic chuck 100, the first insulating layer 120 of the insulating layer is made of an amorphous structure thermal spray coating layer having good volume resistance characteristics, so that the volume resistance is increased and the insulating characteristics are improved.

The first insulating layer 120, the first dielectric layer 150, and the second dielectric layer 160 are used as a post-treatment process for the thermal spray coating process to fill pores and cracks included in the thermal spray coating layer. Can go through. The sealing process may be performed collectively on the first insulating layer 120, the first dielectric layer 150, and the second dielectric layer 160, and may be performed on a group basis or on an individual basis. . The sealing material used for sealing the first insulating layer 120, the first dielectric layer 150, and the second dielectric layer 160 includes a resin. For example, the resin may be a silicon-based acrylic resin.

Through the sealing process, the first insulating layer 120, the first dielectric layer 150, and the second dielectric layer 160 have an effect of increasing the volume resistance. For example, the volume resistance of the second dielectric layer 160 having a crystal structure has about 10 ⁹ to 10 ¹¹ Ω · cm before the sealing treatment, but increases to about 10 ¹³ Ω · cm after the sealing treatment. To do. Further, the volume resistance of the first insulating layer 120 and the first dielectric layer 150 having an amorphous structure has about 10 ¹³ Ω · cm before the sealing process, but after the sealing process, the volume resistance is about 10 ¹⁴ to 10 ¹⁴ . Increase to 10 ¹⁵ Ω · cm. Further, the total volume resistance of the first dielectric layer 150 and the second dielectric layer 160 has about 10 ¹³ Ω · cm before the sealing process, but about 10 ¹⁴ to 10 ¹⁵ Ω · cm after the sealing process. Increase to cm.

Therefore, a dielectric layer with a multilayer structure increases the volume resistance even if it has a sufficient dielectric constant necessary for electrostatic force formation, thereby suppressing arcing by suppressing leakage current and improving electrical characteristics. Let Furthermore, the insulating structure of the amorphous structure is improved because the thermal spray coating layer of the amorphous structure has a high volume resistance.

In the present embodiment, the crystalline second dielectric layer 160 is formed on the amorphous first dielectric layer 150, and the crystalline coating layer is disposed on the uppermost layer (for example, the outermost layer). . From the viewpoint of only the dielectric constant and volume resistance of the dielectric layer, the same effect as described above can be obtained even if an amorphous coating layer is formed on the crystalline coating layer. However, the amorphous coating layer has a high volume resistance in the physical aspect, but has a small coefficient of thermal expansion, so that cracks can occur during the process, and the amorphous coating layer is the most functional in terms of the functional aspect. When positioned in the upper layer, the risk of arcing due to plasma is increased as the dielectric constant increases. Therefore, it is not desirable that the amorphous coating layer be disposed on the top layer, and it is desirable that the crystalline coating layer be disposed on the top layer. Therefore, in the present embodiment, when forming the dielectric layer, the crystalline second dielectric layer 160 is formed on the amorphous first dielectric layer 150 so that the crystalline coating layer is disposed on the uppermost layer. Configure as follows.

FIG. 4 is a schematic view showing the configuration of an electrostatic chuck according to another embodiment of the present invention.

Here, the electrostatic chuck 200 shown in FIG. 4 is very similar to the configuration of the electrostatic chuck 100 described above with reference to FIG. A brief explanation will be given focusing on the point.

An electrostatic chuck 200 according to another embodiment of the present invention includes a base 110, a first insulating layer 220, a second insulating layer 230, an electrode layer 140, a first dielectric layer 150, a second dielectric layer 160, and a connector 170. Including.

The substrate 110 may have a flat plate shape or a cylinder shape, and may be formed of metal. An example of the metal may include aluminum (Al).

The first insulating layer 220 is formed on the substrate 110. The first insulating layer 220 may be formed on a partial region of the upper surface of the substrate 110. The first insulating layer 220 is obtained by a thermal spray coating process using the first thermal spray coating powder and has an amorphous structure. The first insulating layer 220 has a thickness of at least 100 μm, and preferably has a thickness of 100 μm to 300 μm. When the thickness of the first insulating layer 220 is less than 100 μm, the volume resistance is low and the insulating characteristics between the electrode layer 140 and the substrate 110 are deteriorated, which is not desirable. Therefore, the first insulating layer 220 preferably has a thickness of at least 100 μm. First insulating layer 220
Has an amorphous structure and therefore has a porosity of 2% or less, preferably 1% or less. For example, the first insulating layer 220 has a porosity of about 0.5% to 2%, and preferably has a porosity of about 0.5% to 1%. Further, the first insulating layer 220 has a surface roughness (Ra) of 4 μm to 8 μm in order to ensure adhesive strength, and has an adhesive strength of 14 Mpa or more through this. The first insulating layer 220 has a hardness of 650 Hv or higher.

The second insulating layer 230 is formed on the first insulating layer 220. For example, the second insulating layer 230 may be formed corresponding to the upper surface of the first insulating layer 220. The second insulating layer 230 is obtained by a thermal spray coating process using the second thermal spray coating powder. Here, the second thermal spray coating powder is a thermal spray coating powder for forming a crystalline coating layer. For example, the second thermal spray coating powder may include a ceramic. Examples of the ceramic include Al ₂ O ₃ , Y ₂ O ₃ , Al ₂ O ₃ / Y ₂ O ₃ , ZrO ₂ , AlC, TiN, AlN, TiC, MgO, CaO, CeO ₂ , TiO ₂ , BxCy, BN, SiO ₂ , SiC, YAG, Mullite, AlF _{3 and the} like can be mentioned. These can be used alone or in combination.

The second insulating layer 230 has a thickness of 200 um to 400 um. The second insulating layer 230 has a higher porosity than the first insulating layer 220 by having a crystal structure. For example, the first dielectric layer 230 has a porosity of 3% to 7%. The second insulating layer 230 has a surface roughness (Ra) of 3 μm to 5 μm in order to ensure the adhesive strength between the coating layers, and has an adhesive strength of 14 Mpa or more through this. The first dielectric layer 150 has a hardness of 650 Hv or higher.

Meanwhile, in the electrostatic chuck 200, the second insulating layer 230 is formed on the first insulating layer 220. However, the second insulating layer 230 is formed on the substrate 110. Can be done. That is, the second insulating layer 230 can be formed between the base 110 and the first insulating layer 220. In this embodiment, when the first insulating layer 220 and the second insulating layer 230 are formed to insulate the base 110 and the electrode layer 140, the arrangement positions of the first insulating layer 220 and the second insulating layer 230 can be changed. It is. In the electrostatic chuck 200, the insulating layer that insulates the substrate 110 and the electrode layer 140 has a multilayer structure including the amorphous first insulating layer 220 and the crystalline insulating layer 230, thereby increasing the volume resistance. It is sufficient if the insulation resistance characteristic is improved through.

An electrode layer 140 is formed on the second insulating layer 230. For example, the electrode layer 140 can be formed in a partial region of the second insulating layer 230. The electrode layer 140 is made of a conductive material. An example of the conductive material is tungsten.

A first dielectric layer 150 and a second dielectric layer 160 are sequentially formed on the electrode layer 140.

The first dielectric layer 150 and the second dielectric layer 160 serve as a dielectric so that an electrostatic force is formed by the electrode layer 140. The first dielectric layer 150 is obtained by a thermal spray coating process using the first thermal spray coating powder, and the second dielectric layer 160 is obtained by a thermal spray coating process using the second thermal spray coating powder. Accordingly, the first dielectric layer 150 has an amorphous structure, and the second dielectric layer 160 has a crystalline structure.

As described above, the electrostatic chuck 200 is composed of multiple layers in which the insulating layer and the dielectric layer each include the non-crystalline structure spray coating layer and the crystal structure spray coating layer. Therefore, the dielectric constant necessary for forming electrostatic force is secured by the thermal spray coating layer having a crystal structure, the volume resistance is increased by the thermal spray coating layer having an amorphous structure, and the insulation resistance is increased by increasing the volume resistance. The characteristics are improved. As a result, since the volume resistance is increased without decreasing the dielectric constant, the electrical resistance is improved by improving the insulation resistance characteristics and improving the defect due to the leakage current.

The connector 170 is connected to the electrode layer 140 through the base 110, the first insulating layer 220 and the second insulating layer 230. The connector 170 serves to apply a high voltage from the outside to the electrode layer 140.

The connector 170 has the same structure as that described with reference to FIGS. 2 and 3 except that the connector 170 passes through the base 110, the first insulating layer 220, and the second insulating layer 230 and is connected to the electrode layer 140. Very similar. That is, in the electrostatic chuck 100 described with reference to FIG. 1, only the first insulating layer 120 is positioned between the base 110 and the electrode layer 140, but in the electrostatic chuck 200, the base 110 and the electrode are disposed. The first insulating layer 220 and the second insulating layer 230 are positioned between the layer 140 and the layer 140. Except for these differences, the configuration is the same as that described above, and thus the detailed description of the connector 170 is replaced with the above description.

Hereinafter, the effects of the electrostatic chuck according to the present invention will be briefly described through comparison between the electrostatic chuck according to the present invention and the conventional electrostatic chuck.

FIG. 5 is a graph showing the insulation resistance according to the voltage applied to the electrode layer in the electrostatic chuck according to the present invention and the electrostatic chuck according to the prior art.

Here, the electrostatic chucks 100 and 200 of the present invention and the conventional electrostatic chuck have the same conditions as the following. The size of the electrostatic chuck is 300φ × 45T, the thickness of the entire coating layer (for example, the insulating layer and the dielectric layer) formed on the substrate has a range of 950 μm to 1050 μm, and the thickness of the dielectric layer The length has a range of 400 um to 500 um. The insulation resistance was measured by increasing the voltage applied to the electrode layer from 500V to 2500V in steps of 500V.

As shown in FIG. 5, the insulation resistance of the dielectric layers of the electrostatic chucks 100 and 200 according to the present invention is at least 2.5 times higher than the insulation resistance of the dielectric layer of the conventional electrostatic chuck. Therefore, a dielectric layer having a multilayer structure including an amorphous thermal spray coating layer and a crystalline thermal spray coating layer according to the present invention has a significantly higher volume resistance than a dielectric layer composed of a single crystalline layer. I understand that.

Therefore, in the case of the electrostatic chucks 100 and 200 according to the present invention, the leakage current is reduced by increasing the insulation resistance of the dielectric layer, and arcing due to the leakage current is reduced due to the reduction of the leakage current. Since the occurrence of defects is reduced, the electrical characteristics are improved.

In particular, in the conventional electrostatic chuck, it can be seen that the change in the insulation resistance accompanying the stepwise increase in the voltage applied to the electrode layer from 500 V to 2500 V is very small. That is, the conventional electrostatic chuck has an insulation resistance of about 5530 MΩ when a voltage of 500 V is applied to the electrode layer, and has an insulation resistance of about 5780 MΩ that does not change much when a voltage of 2500 V is applied to the electrode layer. Has resistance. When the voltages applied to the electrode layers are 1000 V, 1500 V, and 2000 V, they have insulation resistances of 5640 MΩ, 5780 MΩ, and 5650 MΩ, respectively. Therefore, in the conventional electrostatic chuck, as the voltage applied to the electrode layer is increased, the leakage current increases (since the current is proportional to the voltage with the same resistance), and the increase in the leakage current is Induces defects such as arcing. Thus, the electrical characteristics of the conventional electrostatic chuck deteriorate as the voltage applied to the electrode layer is increased.

On the other hand, in the electrostatic chucks 100 and 200 according to the present invention, the voltage applied to the electrode layer is 500V.
It can be seen that the insulation resistance increases with a gradual increase from 2500 to 2500V. When a voltage of 500 V is applied to the electrode layer, it has an insulation resistance of about 14,900 MΩ and 2
It can be seen that when a voltage of 500 V is applied, it has an insulation resistance of about 24,600 MΩ, and the insulation resistance has increased by about 65%. Further, when the voltages applied to the electrode layers are 1000 V, 1500 V, and 2000 V, 18,200 MΩ, 21,200 MΩ, 23.5, respectively.
It has an insulation resistance of 00 MΩ. Therefore, in the case of the electrostatic chuck according to the present invention, it is understood that the increase in the leakage current is not large because the insulation resistance increases when the voltage applied to the electrode layer is increased (for example, the voltage is increased). . In this way, even when the voltage applied to the electrode layer is increased, the leakage current can be maintained at a low level, so that defects such as arcing due to the leakage current can be suppressed.

In conclusion, in the electrostatic chucks 100 and 200 according to the present invention, the dielectric resistance (or insulating layer) includes a multilayer including an amorphous structure coating layer and a crystal structure coating layer, thereby increasing the insulation resistance. Has an effect. The increase in the insulation resistance has an effect of reducing the leakage current, and the reduction in the leakage current suppresses defects such as arcing and improves the electrical characteristics.

FIG. 6 is a graph showing the leakage current and the amount of He leakage according to the usage time of the electrostatic chuck according to the present invention and the conventional electrostatic chuck.

As shown in FIG. 6, it can be seen that the leakage current that accompanies the usage time of the electrostatic chucks 100 and 200 of the present invention is lower than the leakage current that accompanies the usage time of the conventional electrostatic chuck.

In general, during the manufacturing process of a semiconductor substrate, the temperature of the substrate is increased by plasma. However, since the increase in the temperature of the substrate causes a process failure, it is necessary to lower the temperature of the substrate. For this purpose, the substrate is maintained at an appropriate temperature by supplying a temperature adjusting helium (He) gas to the lower surface of the substrate through a through hole formed through the substrate and the coating layer to cool the substrate. . That is, helium (He) gas serves as a cooling gas. The supply amount of the helium (He) gas varies depending on the adsorption force of the electrostatic chuck. For example, if the chucking force of the electrostatic chuck is good, the sealing between the substrate and the electrostatic chuck is improved, and the amount of gas leaked to the outside through the space between the substrate and the electrostatic chuck is reduced. If the attractive force is poor, the sealing between the substrate and the electrostatic chuck is relatively poor and the amount of leaked gas increases.

From the above viewpoint, during the manufacturing process using the electrostatic chuck 100 of the present invention, the amount of helium (He) gas leakage is the amount of helium (He) gas leakage during the manufacturing process using the conventional electrostatic chuck. Therefore, it can be seen that the electrostatic chucks 100 and 200 of the present invention have a relatively good electrostatic attraction force. In particular, it can be seen that, in the conventional electrostatic chuck, the variation range of the amount of helium (He) gas leakage that appears with the passage of time of use appears greatly. That is, it can be seen that the uniformity of the amount of leakage of helium (He) gas is reduced in the manufacturing process using the conventional electrostatic chuck. On the other hand, it can be seen that the change width of the supply amount of helium (He) gas that appears with the passage of time of use is very small in the electrostatic chuck of the present invention.

As a result, in the electrostatic chucks 100 and 200 of the present invention, the leakage current and the amount of helium (He) gas leakage are lower than those of the conventional electrostatic chuck. This data refutes that the electrostatic chucking force of the conventional electrostatic chuck has been improved. Furthermore, the electrostatic chucks 100 and 200 of the present invention can ensure the uniformity of the electrostatic adsorption force with the passage of time of use.

FIG. 7 is a graph illustrating the etching rate after the etching process using the electrostatic chuck according to the present invention, and FIG. 8 is a graph illustrating the etching rate after the etching process using the conventional electrostatic chuck.

Here, except that the electrostatic chuck according to the present invention and the electrostatic chuck according to the prior art are used, after performing the etching process under the same process conditions, the area of the object to be etched is divided into a matrix form and each area is divided. It is the graph which showed the etching rate. The etching process conditions are such that the gap (Gap) of the plasma formation space is 120 mm, the process pressure is 250 mTorr, and the RF voltage is 5 kW. The supply amounts of process gases SF ₆ and O ₂ are 400 mTorr and 7000 mTorr, respectively.

Etching rate of etching process using electrostatic chuck of the present invention

Etching rate of etching process using conventional electrostatic chuck

Here, the etching uniformity is obtained by the following equation.
[Equation 1]
Etching uniformity = (maximum value−minimum value) / (maximum value + minimum value)

7 and 8 are graphs illustrated based on the above [Table 1] and [Table 2], respectively.

Referring to FIGS. 7 and 8, the etching average value of the etching process using the electrostatic chucks 100 and 200 according to the present invention is 13290.7, and the etching average value of the etching process using the conventional electrostatic chuck is 10840.7. That is, the electrostatic chuck 10 of the present invention.
It can be seen that when the etching process is performed using the 0, 200 electrostatic chuck, the etching rate is relatively improved.

Further, the etching uniformity of the etching process using the conventional electrostatic chuck is about 18.80.
On the other hand, the etching uniformity of the etching process using the electrostatic chucks 100 and 200 of the present invention is measured to be about 7.15%, which is relatively uniform when using the electrostatic chucks 100 and 200 of the present invention. It can be seen that a simple etching is possible.

As described above, when the electrostatic chucks 100 and 200 of the present invention are used, a more uniform etching surface can be formed. Therefore, when the electrostatic chucks 100 and 200 are used, the reliability of the etching process is improved. Has the effect.

Hereinafter, the first thermal spray coating powder for forming the thermal spray coating layer having an amorphous structure will be briefly described.

FIG. 9 is a photograph for explaining a first thermal spray coating powder used for forming the thermal spray coating layer having an amorphous structure shown in FIG.

Referring to FIG. 9, the first thermal spray coating powder is obtained from a mixed slurry composition of a first slurry composition and a second slurry composition. The content of the composition described below is based on weight percent.

The first slurry composition includes yttrium oxide particles, a first dispersant, a first binder, and an extra first solvent.

The yttrium oxide particles have a diameter of about 0.01 um to 2 um. When the diameter of the yttrium oxide particles is less than 0.01 um, the average particle diameter of the first thermal spray coating powder can be reduced, and it is difficult to form spherical coarse particles, which is not desirable, and the diameter exceeds 2 um. If this is the case, the particles can be agglomerated and the average diameter of the coarse particles can be too large, which is undesirable.

The first dispersant serves to evenly disperse the yttrium oxide particles in the first slurry composition. The first dispersant may have basicity. Examples of the first dispersant include a carboxyl-based material, an ester-based material, an amide-based material, and the like. These can be used alone or in combination of two or more. . The first dispersant may have a pH of about 10-12, and more desirably, the pH may be about 10. In the first dispersant having basicity, the yttrium oxide has a (−) surface charge. The content of the first dispersant is preferably about 0.3% to 0.5%. If the content of the first dispersant exceeds about 0.5%, the first thermal spray coating powder cannot be formed into a spherical shape through the spray drying process, and if the content is less than about 0.3%, The viscosity of the slurry composition is increased, which is undesirable.

The first binder provides a bonding force between yttrium oxide particles in the first slurry composition. The content of the first binder is preferably about 2% to 3%. When the content of the first binder is less than about 2%, the yttrium oxide particles are not sufficiently bound, and the first thermal spray coating powder cannot be formed into a sphere, and when the content exceeds about 3%, This is not desirable because the viscosity of the first slurry composition increases rapidly. Examples of the first binder include vinyl materials and acrylic materials.

The first slurry composition includes an extra first solvent. The first solvent may be the organic material or an aqueous system. When the first binder is a vinyl material, the first solvent is preferably an organic material such as ethanol, and when the first binder is an acrylic material, the first solvent is an aqueous material. desirable. Examples of the vinyl-based substance include ethylene vinyl acetate resin, polyvinyl chloride resin, polyvinyl pyrrolidine, polyvinyl alcohol resin, polyvinyl butyral, polyvinyl acetate, polyvinyl ether, etc., which are used alone or Two or more can be mixed and used. Examples of the acrylic material include methacrylic resin, polymethyl methacrylic resin, polyacrylonitrile resin, normal butyl acrylic resin, polystyrene polymethyl methacrylic resin, etc., which are used alone or Two or more can be mixed and used.

The first slurry composition may be formed using a ball mill. The solid content ratio of the first slurry composition is proportional to the content of the first dispersant. In the first slurry composition, when the solid content ratio is less than about 20%, the size of coarse particles may be small in the first solvent, and when it exceeds about 30%, the viscosity increases. Therefore, the process control for producing the first thermal spray coating powder is not easy, and a non-spherical powder can be generated. Therefore, the solid content ratio of the first slurry composition is preferably about 20% to 30%.

The second slurry composition includes aluminum oxide particles, a second dispersant, a second binder, and an extra second solvent.

For example, the aluminum oxide particles have a diameter of about 0.5 um to 2 um. When the diameter of the aluminum oxide particles is less than about 0.5 um, the average diameter of the first thermal spray coating powder can be reduced, making it difficult to form spherical coarse particles, and exceeding about 2 um. The average diameter of coarse particles can be too large.

The second dispersant serves to uniformly disperse the aluminum oxide particles in the second slurry composition. The second dispersant may have acidity. Examples of the second dispersant include a carboxyl material, an ester material, and an amide material. These can be used alone or in combination of two or more. The second dispersant may have a pH of about 2 to 4, and more desirably has a pH of about 2. In the second dispersant having basicity, the aluminum oxide has a (+) surface charge. The content of the second dispersant is preferably about 0.3% to 2%. The second
The range of the content of the dispersant has the same reason as the case of the first dispersant in the first slurry composition.

The second binder provides a binding force between the aluminum oxide particles in the second slurry composition. The content of the second binder is preferably about 2% to 3%. When the content of the second binder is less than about 2%, the aluminum oxide particles are not sufficiently bonded to form the first thermal spray coating powder into a spherical shape, and exceeds about 3%. In some cases, the first thermal spray coating powder can be formed into a spherical shape, but this is not desirable because the viscosity of the second slurry composition increases rapidly. The description for the second binder example is substantially the same as the description for the first binder example.

The second slurry composition includes an extra second solvent. The second solvent may be the organic material or an aqueous system. The description for the second solvent is substantially the same as the description for the first solvent.

The second slurry composition may be formed using a ball mill. The ratio of the solid content of the second slurry composition is proportional to the content of the second dispersant. When the ratio of the solid content of the second slurry composition is less than about 20%, the aluminum oxide powder content may be low in the second solvent and the size of the coarse particles may be small. In the case of exceeding the viscosity, the viscosity increases and the process control for producing the first thermal spray coating powder is not easy, and a non-spherical powder can be produced. Accordingly, the solid content ratio of the second slurry composition is preferably about 20% to 30%.

When the weight ratio of the yttrium oxide to the aluminum oxide is 1: 9 to 4: 6 in the mixed slurry composition, the coating layer formed using the first thermal spray coating powder obtained from the mixed slurry composition is , Mainly has the characteristics of aluminum oxide, and has the disadvantage of high strength but weak adhesion. When the weight ratio of the yttrium oxide to the aluminum oxide is 8: 2 to 9: 1 in the mixed slurry composition, the coating layer formed using the first thermal spray coating powder obtained from the mixed slurry composition is , It mainly has the characteristics of yttrium oxide and has the disadvantages of low strength and adhesive strength. Accordingly, the yttrium oxide and the aluminum oxide in the mixed slurry composition preferably have a weight ratio of about 5: 5 to about 7: 3, and more preferably about 5: 5.

The first thermal spray coating powder includes coarse particles obtained from a slurry composition obtained by mixing the first slurry composition and the second slurry composition, and the coarse particles have an average of about 20 um to 60 um. More desirably, it has a diameter and an average diameter of about 30 um to 40 um. When the average diameter of the coarse particles is less than about 20 um, it is not desirable because when the thermal spray coating is performed because the size of the powder is too small, the powder itself may not be sufficiently transmitted to the object. In the case of exceeding about 60 um, when the spray coating is performed because the powder is too large, a phenomenon such as lumping may occur and a uniform coating may not be realized.

FIG. 10 is a process diagram for explaining a method of manufacturing the first thermal spray coating powder shown in FIG.

Referring to FIG. 10, in the method for manufacturing the first thermal spray coating powder, first, a first slurry composition is formed (S110). The first slurry composition includes yttrium oxide particles having a diameter of 0.01 um to 2 um, a first dispersant that uniformly disperses the yttrium oxide particles, a first binder that provides a binding force between the yttrium oxide particles, and Contains extra first solvent. When the bonding strength between the yttrium oxide particles is sufficient, the first slurry composition may not include the first binder.

FIG. 11 is a process diagram for explaining a method of forming the first slurry composition shown in FIG.

Referring to FIG. 11, the first slurry composition is formed by preparing a first solvent (S111), and sequentially adding yttrium oxide particles having a diameter of 0.01 um to 2 um into the first solvent ( S112), the first dispersant is charged at a content of about 0.3% to 0.5% (S113), and the first binder is charged at a content of about 2% to 3% (S114). Here, the yttrium oxide particles have a (−) surface charge due to the first dispersant. Unlike this, the order in which the yttrium oxide particles, the first dispersant, and the first binder are added to the first solvent may be changed.

Thereafter, the yttrium oxide particles, the first dispersant, the first binder, and the first solvent are mixed with each other using a ball mill to form the first slurry composition.

Referring to FIG. 10 again, a second slurry composition is formed (S120).

The second slurry composition comprises aluminum oxide particles having a diameter of 0.5 um to 2 um,
A second dispersant for uniformly dispersing the aluminum oxide particles, a second binder for providing a binding force between the aluminum oxide particles, and an extra second solvent are included. When the bonding strength between the aluminum oxide particles is sufficient, the second slurry composition may not include the second binder.

FIG. 12 is a process diagram for explaining a method of forming the second slurry composition shown in FIG.

Referring to FIG. 12, a second solvent is prepared (S121), and 0.5 um is sequentially added to the second solvent.
Aluminum oxide particles having a diameter of ˜2 μm are charged (S122), about 0.3% to 2%
The second dispersing agent is charged at a content of (S123), and the second binder is charged at a content of about 2% to 3% (S124). Here, the aluminum oxide particles have a (+) surface charge due to the second dispersant. Unlike this, the order in which the aluminum oxide particles, the second dispersant, and the second binder are added to the second solvent may be changed.

Thereafter, the aluminum oxide particles, the second dispersant, the second binder, and the solvent are mixed with each other using a ball mill to form the second slurry composition.

Referring to FIG. 10, the first slurry composition and the second slurry composition are mixed to form a mixed slurry composition (S130). At this time, the yttrium oxide of the first slurry composition and the aluminum oxide of the second slurry composition have a weight ratio of 7: 3 to 5: 5, that is, a weight ratio of 1: 0.4 to 1.

FIG. 13 is a view for explaining the binding of yttrium oxide and aluminum oxide in the method of forming the mixed slurry composition shown in FIG.

Referring to FIG. 13, since the yttrium oxide has a (−) surface charge and the aluminum oxide has a (+) surface charge, the yttrium oxide can be easily bonded by electrostatic attraction.

Referring to FIG. 10 again, the mixed slurry composition is subjected to a spray drying process to form coarse particles including yttrium oxide and aluminum oxide (S140). The spray drying step is performed by heating at a high temperature while spraying the mixed slurry composition from a spray dryer. The spray drying process is desirably performed at a temperature of about 800 ° C. to 1500 ° C., and coarse particles having high hardness can be formed in the spray drying process within the temperature range.

Performing the spray drying process, the mixed slurry composition has an average particle diameter of about 20 um to 60 um and is formed of coarse particles including yttrium oxide and aluminum oxide.

Meanwhile, a manufacturing process of the first thermal spray coating powder, that is, a step of forming the first slurry composition (S110), a step of forming the second slurry composition (S120), and forming the mixed slurry composition. The step of performing (S130) and the step of spray drying the mixed slurry composition (S140) may be performed in an atmosphere of air, hydrogen, oxygen, and nitrogen, or an atmosphere in which these are mixed.

Hereinafter, an electrostatic chuck manufacturing method according to the present invention will be described. Here, the configuration of the electrostatic chuck 200 illustrated in FIG. 4 and the configuration of the connector 170 illustrated in FIG. 3 will be described as a reference.

FIG. 14 is a process diagram for explaining an electrostatic chuck manufacturing method according to an embodiment of the present invention.

Referring to FIGS. 3, 4, and 14, the method for manufacturing the electrostatic chuck 200 according to the present invention prepares the substrate 110 (S <b> 210). The substrate 110 may have a flat plate shape or a cylinder shape. The base 110 prepares the connector 170 in a state where a through hole for insertion is formed.

The connector 170 is prepared (S220). The preparation of the connector 170 is performed separately from the preparation stage of the base body 110. The connector 170 is prepared in a state in which an insulating member 178 is formed around the terminal 177 and a first buffer layer 179a is formed in a part of the upper portion of the insulating member 178.

When the base 110 and the connector 170 are separately prepared, the connector 170 is then inserted into the through hole for the connector 170 formed in the base 110 (S230). That is, the connector 170 is placed at a fixed position on the base 110. If the connector 170 is disposed at a fixed position, the second buffer layer 179b is formed. The second buffer layer 179b is formed in a part of a region between the first insulating layer 220 and the insulating member 178 to be formed below and a contact surface between the first insulating layer 220 and the base 110.

Subsequently, the bonding layer 115 is formed on the upper surface of the substrate 110 except for the connector 170 region including the second buffer layer 179b (S240). The bonding layer 115 is formed for adhesion between the substrate 110 and the first insulating layer 220 and includes a metal alloy. An example of the metal alloy is a nickel-aluminum alloy.

Subsequently, a thermal spray coating process using the first thermal spray coating powder is performed on the substrate 110 to form the first insulating layer 220 having an amorphous structure (S250). The first insulating layer 220 is formed in a partial region of the upper surface of the base 110. Since the first thermal spray coating powder has been described with reference to FIGS. 8 and 12, a detailed description thereof will be omitted. The first insulating layer 220 is formed by a thermal spray coating process in which the first thermal spray coating powder is melt sprayed. Examples of the spray coating process include an atmospheric plasma spray (APS) process, a high-speed oxygen-fuel spray process, a vacuum plasma spray process, and a kinetic spray process.

Subsequently, a second insulating layer 230 having a crystal structure is formed on the first insulating layer 220 by performing a thermal spray coating process using the second thermal spray coating powder (S260). The second insulating layer 230 is formed on the upper surface of the first insulating layer 220. The second thermal spray coating powder is a powder for forming a crystalline coating layer, and may include ceramic. Examples of the ceramic include Al ₂ O ₃ , Y ₂ O ₃ , Al ₂ O ₃ / Y ₂ O ₃ , ZrO ₂ , AlC, TiN, AlN, TiC, MgO, CaO, CeO ₂ , TiO ₂ , BxCy, BN , SiO ₂ , SiC, YAG, Mullite, AlF _{3 and the} like, and these can be used alone or in combination.

The second insulating layer 230 is formed by a thermal spray coating process in which the second thermal spray coating powder is melt sprayed. Examples of the spray coating process include an atmospheric plasma spray (APS) process, a high-speed oxygen-fuel spray process, a vacuum plasma spray process, and a kinetic spray process. That is, the method is the same as the method for forming the first insulating layer 130 except that different coating powders are used.

After the second insulating layer 230 is formed, a step of adjusting the flatness of the second insulating layer 230 is performed. Further, the contact portion (for example, the upper end plane) of the connector 170 is exposed so that the connector 170 can be in contact with the electrode layer 140 to be formed while performing the flatness adjusting step of the second insulating layer 230. On the other hand, in the case of the electrostatic chuck 100 illustrated in FIG. 1, only the first insulating layer 120 is formed between the base 110 and the electrode layer 140, and thus the first insulating layer 120 is formed after the first insulating layer 120 is formed. In this process, the connector 170 is exposed.

Subsequently, the electrode layer 140 is formed on the second insulating layer 230 using a conductive material (S270). The electrode layer 140 can be formed in a partial region of the upper surface of the second insulating layer 230. An example of a conductive material for forming the electrode layer 140 is tungsten.

Subsequently, after forming the electrode layer 140, a thermal spray coating process using the first thermal spray coating powder is performed on the electrode layer 140 to form the first dielectric layer 150 having an amorphous structure (S280). The first dielectric layer 150 is formed on the remaining region of the upper surface of the second insulating layer 230 where the electrode layer 140 is not formed and on the upper surface of the electrode layer 140. That is, the first dielectric layer 150 is formed to completely enclose the electrode layer 140. The first thermal spray coating powder for forming the first dielectric layer 150 is the same as the powder for forming the first insulating layer 220. Examples of the thermal spray coating for forming the first dielectric layer 150 are described above. This is the same as the example of the thermal spray coating for forming the first insulating layer 220.

Subsequently, a thermal spray coating process using the second thermal spray coating powder is performed on the first dielectric layer 150 to form a crystalline second dielectric layer 160 (S290). The second dielectric layer 160 is formed so as to completely enclose the first dielectric layer 150. Further, the second dielectric layer 160 has a remaining region (for example, an end region) of the upper end surface of the substrate 100 on which the coating layer is not formed and a side surface of the substrate 110. The side surfaces of the first insulating layer 220 and the second insulating layer 230 and the side surfaces of the first dielectric layer 150 are coated simultaneously. That is, the second dielectric layer 160 coats the exposed surfaces of all the coating layers 220, 230, and 150 including the substrate 110. In the formation process, a thermal spray interface between the coating layers 220, 230, and 150 may exist, but the thermal spray interface may develop into a future crack, and the crack may cause arcing. It becomes a problem. Therefore, when the second dielectric layer 160 is formed in order to improve such a problem, the second dielectric layer 160 is simultaneously coated to the exposed portions of the side surfaces of the coating layers 220, 230, 230 as well as the substrate 110.

The second thermal spray coating powder used to form the second dielectric layer 160 is the same as the coating powder used to form the second insulating layer 230. Further, an example of the thermal spray coating for forming the second dielectric layer 160 is the same as the example of the thermal spray coating for forming the first insulating layer 220 described above.

After the second dielectric layer 160 is formed, a protrusion may be processed on the upper surface of the second dielectric layer 160.

When the first dielectric layer 150 and the second dielectric layer 160 are formed, the first insulating layer 220 and the second insulating layer 230 and a sealing hole for filling pores included in the first dielectric layer 150 and the second dielectric layer 160 are formed. Processing is performed (S300). The sealing process is performed using a sealing material. The sealing material includes a resin. For example, the resin may be a silicon-based acrylic resin. By filling the pores included in the first dielectric layer 220 and the second dielectric layer 230 and the first dielectric layer 150 and the second dielectric layer 160 through the sealing process, the volume resistance is increased.

Meanwhile, in the above description, it has been described that the sealing process is performed collectively after the first insulating layer 220 and the second insulating layer 230 and the first dielectric layer 150 and the second dielectric layer 160 are formed. In contrast, the sealing process may be performed after the first insulating layer 220 and the second insulating layer 230 and the first dielectric layer 150 and the second dielectric layer 160 are formed, respectively, or the first insulating layer is formed. 220 and the second insulating layer 230, and the first dielectric layer 150 and the second dielectric layer 160 may be divided into groups. That is, the sealing process time and the number of processes can be changed.

In the above description, the flat adjustment step is described only for the second insulating layer 230. However, after each step is formed, a flat adjustment step may be included as necessary. That is, after the bonding layer 115, the first insulating layer 220, the electrode layer 140, the first dielectric layer 150, and the second dielectric layer 160 are formed, it is possible to apply a flat adjustment step as necessary.

In the above electrostatic chuck manufacturing method, the electrostatic chuck 200 illustrated in FIG. 4 has been described as a reference. That is, the method for manufacturing the electrostatic chuck 200 having a multilayer structure in which the insulating layer includes the amorphous first insulating layer 220 and the crystalline second insulating layer 230 has been described.

In contrast, as shown in FIG. 1, in the case of the electrostatic chuck 100 in which the insulating layer is an amorphous single layer, the step of forming the second insulating layer 230 (S260) is omitted. After forming the first insulating layer 120, only the difference in forming the electrode layer 140 on the first insulating layer 120 is provided.

As described above, according to the electrostatic chuck and the method of manufacturing the same of the present invention, the dielectric layer is composed of a multilayer composed of an amorphous thermal spray coating layer and a crystalline thermal spray coating layer. Since the volume resistance increases without decreasing the dielectric constant through the high quality thermal spray coating layer, it is possible to realize an electrostatic chuck with improved electrical characteristics by suppressing the occurrence of arcing due to leakage current.

In addition, since the insulating layer includes an amorphous sprayed coating layer, the insulating property between the substrate and the electrode layer is improved through the high volume resistance characteristic of the amorphous sprayed coating layer. A chuck can be implemented.

In addition, by providing a buffer layer at the terminal connection for applying a high voltage to the electrode layer, it is possible to improve cracks generated at the terminal connection site due to thermal stress generated during the process. Durability can be improved and maintenance costs can be reduced. Furthermore, the life of the electrostatic chuck can be increased.

Therefore, it can be desirably used in a semiconductor manufacturing apparatus that requires an electrostatic chuck having stable electrical characteristics and improved durability.

  The preferred embodiments of the present invention have been described in detail above, but those skilled in the art to which the present invention pertains can be embraced within the spirit and scope of the present invention described in the following claims. It is understood that the present invention can be modified and changed in various ways.

Claims (16)

A substrate;
An amorphous first insulating layer formed on the substrate;
An electrode layer for generating electrostatic force formed on the first insulating layer;
Look including a dielectric layer formed on the electrode layer,
The dielectric layer is
An amorphous first dielectric layer formed on the electrode layer;
An electrostatic chuck comprising: a crystalline second dielectric layer formed on the first dielectric layer . The electrostatic chuck according to claim 1 , wherein the first dielectric layer has a thickness of 100 μm to 300 μm, and the second dielectric layer has a thickness of 200 μm to 400 μm. The first dielectric layer has a porosity of 0.5% to 2%, and the second dielectric layer has a porosity of 3% to 7%.
The electrostatic chuck according to claim 1 , wherein: The electrostatic capacitance according to claim 1 , wherein the first dielectric layer has a surface roughness (Ra) of 4 um to 8 um, and the second dielectric layer has a surface roughness (Ra) of 3 um to 5 um. Chuck. The electrostatic chuck according to claim 1 , wherein the first and second dielectric layers have a hardness of 650 Hv or more and an adhesive strength of 14 Mpa or more. 2. The electrostatic chuck according to claim 1 , wherein a total volume resistance of the first dielectric layer and the second dielectric layer is 10 ¹⁴ to 10 ¹⁵ Ω · cm. The electrostatic chuck according to claim 1 , wherein the electrode layer is embedded by the first dielectric layer, and the first dielectric layer is embedded by the second dielectric layer. The electrostatic chuck according to claim 1, wherein the first insulating layer has a thickness of 400 μm to 600 μm.   The electrostatic chuck according to claim 1, further comprising a crystalline second insulating layer formed between the base and the electrode layer. The electrostatic chuck according to claim 9 , wherein the first insulating layer has a thickness of 100 μm to 300 μm, and the second insulating layer has a thickness of 200 μm to 400 μm. Preparing a substrate;
Forming an amorphous first insulating layer on the substrate;
Forming an electrode layer for generating electrostatic force on the first insulating layer;
See containing and forming a dielectric layer on the electrode layer,
Forming the dielectric layer comprises:
Forming an amorphous first dielectric layer on the electrode layer;
Forming a crystalline second dielectric layer on the first dielectric layer . The first dielectric layer is formed to wrap around the electrode layer,
The method of claim 11 , wherein the second dielectric layer is formed so as to enclose the first insulating layer, the first dielectric layer, and the substrate. The first insulating layer, the first dielectric layer, and the second dielectric layer are formed by any one of an atmospheric plasma spraying process, a high-speed oxygen-fuel spraying process, a vacuum plasma spraying process, or a kinetic injection process. The method of manufacturing an electrostatic chuck according to claim 11 . The method further includes a step of sealing the first insulating layer, the first dielectric layer, and the second dielectric layer individually or in groups or collectively using a sealing material. The method for manufacturing an electrostatic chuck according to claim 11 . The method further includes forming a crystalline second insulating layer on the first insulating layer before forming the electrode layer or on the substrate before forming the first insulating layer. The method of manufacturing an electrostatic chuck according to claim 11 . The second insulating layer is formed by any one of an atmospheric plasma spraying process, a high-speed oxygen-fuel spraying process, a vacuum plasma spraying process, or a kinetic injection process, and the first insulating layer and the second insulating layer. When, according to claim 15, characterized in that with respect to the first dielectric layer and the second dielectric layer, further comprising the step of sealing treatment using the individual or group basis or collectively sealing treatment material The electrostatic chuck manufacturing method as described in 2.