JP2021145114A - Susceptor and electrostatic chuck device - Google Patents

Abstract

To provide a susceptor and an electrostatic chuck device including the same, which can suppress a change in a contact area between a power feed terminal and an electrode pin even if the electrode pin is tilted with respect to the power feed terminal due to shear stress caused by a difference in linear expansion coefficients of a mounting plate, a support plate, an internal electrode, etc.SOLUTION: A susceptor 1 includes an electrode 4 installed inside a ceramic plate 3 having a mounting surface 3a for placing a sample and a power supply terminal 5 provided through a ceramic plate 2 to contact an electrode 4. On the surface opposite to the mounting surface 3a, there is a recess 6 that includes at least the power supply terminal 5 and is concave toward the mounting surface 3a.SELECTED DRAWING: Figure 1

Description

The present invention relates to a susceptor and an electrostatic chuck device.

In recent years, in dry etching equipment and CVD equipment used in semiconductor manufacturing processes such as ICs, LSIs, and VLSIs, semiconductor wafers, liquid crystal substrate glass, etc. are used in order to uniformly perform film formation by etching or CVD for each wafer. Sheet-wafering is progressing in which plate-shaped samples such as printed substrates are processed one by one. In this single-wafer process, in order to hold the plate-shaped samples one by one in the processing chamber, the plate-shaped samples are placed on a sample table (pedestal) called a susceptor and subjected to a predetermined treatment. ..
Since this susceptor needs to be able to withstand use in plasma and high temperature, it is required to have excellent plasma resistance and high thermal conductivity. As such a susceptor, a susceptor made of a ceramics sintered body having excellent plasma resistance and thermal conductivity is used.

Such a susceptor includes an electrode for an electrostatic chuck for generating an electric charge inside and fixing the plate-shaped sample by electrostatic attraction, a heater electrode for heating the plate-shaped sample by energizing and generating heat, and a high frequency. Some are provided with internal electrodes such as electrodes for generating plasma for generating plasma by energizing electric power (see, for example, Patent Document 1).

FIG. 7 is a cross-sectional view showing an example of a susceptor having a built-in internal electrode as described above. The susceptor 600 shown in FIG. 7 is sandwiched and held between a mounting plate 601 on which a plate-shaped sample (not shown) is placed, a support plate 602 for supporting the mounting plate 601 and the mounting plate 601 and the support plate 602. It has an internal electrode 603 and feeding terminals 604 and 604 embedded in a support plate 602 so as to be in contact with the internal electrode 603 and supplying a current to the internal electrode 603.

A connection structure is known in which an electrode pin is pressed against a power supply terminal to connect the power supply terminal and the electrode pin in order to supply a current to the power supply terminal (see, for example, Patent Document 2). In this connection structure, shear stress due to the difference in linear expansion rate of the mounting plate, support plate, internal electrode, etc. is applied to the connection portion between the power feeding terminal and the electrode pin, so that the shear stress is relaxed. It is effective for.

Japanese Patent No. 3746935 Japanese Patent No. 6228031

However, in the connection structure of Patent Document 2, since the electrode pin is pressed against the flat power feeding terminal, the shear stress caused by the difference in the linear expansion rate of the mounting plate, the support plate, the internal electrode, etc. is applied to the connection portion. When this is applied, the electrode pin is tilted with respect to the power feeding terminal, the contact area between the feeding terminal and the electrode pin changes, and there is a problem that a predetermined amount of current cannot be supplied from the electrode pin to the feeding terminal.

The present invention has been made in view of the above circumstances, and the electrode pins are tilted with respect to the feeding terminal due to shear stress caused by the difference in linear expansion rate of the mounting plate, the support plate, the internal electrodes, and the like. However, it is an object of the present invention to provide a susceptor capable of suppressing a change in the contact area between the power feeding terminal and the electrode pin, and an electrostatic chuck device including the susceptor.

In order to solve the above problems, one aspect of the present invention is to penetrate an electrode provided inside a ceramic plate having a mounting surface on which a sample is placed and the ceramic plate so as to be in contact with the electrode. Provided is a susceptor comprising a power feeding terminal provided, and having at least the power feeding terminal on a surface opposite to the previously described mounting surface and having a recess recessed on the previously described mounting surface side.

In one aspect of the present invention, the cross-sectional shape of the inner surface of the recess in the thickness direction of the ceramic plate may be curved or hyperbolic represented by at least one curvature or a quadratic function.

In one aspect of the present invention, it may have a metal layer that covers the inner surface.

In one aspect of the present invention, the arithmetic mean roughness (Ra) of the surface of the metal layer opposite to the inner surface may be 2 μm or more and 30 μm or less.

In one aspect of the present invention, the electrode and the feeding terminal may be a composite of an insulating substance and a conductive substance.

In one aspect of the invention, the insulating material is at least one selected from the group consisting of aluminum oxide, aluminum nitride, silicon nitride, yttrium oxide (III), yttrium aluminum garnet and SmAlO _3. May be good.

In one aspect of the invention, the conductive material is _{at least one selected from the group consisting of Mo 2} C, Mo, WC, W, TaC, Ta, SiC, carbon black, carbon nanotubes and carbon nanofibers. There may be.

One aspect of the present invention is an electrostatic chuck device in which an electrostatic chuck member made of ceramics and a temperature control base member made of metal are joined via an adhesive layer, and the electrostatic chuck member. Provides an electrostatic chuck device comprising a susceptor according to one aspect of the present invention.

According to the present invention, even if the electrode pin is tilted with respect to the power supply terminal due to shear stress caused by the difference in linear expansion rate of the mounting plate, the support plate, the internal electrode, etc., the contact between the power supply terminal and the electrode pin A susceptor capable of suppressing a change in area and an electrostatic chuck device including the susceptor can be provided.

It is sectional drawing which shows the susceptor which concerns on one Embodiment of this invention. It is sectional drawing which shows the electrostatic chuck device which concerns on one Embodiment of this invention. It is a top view which shows the 1st modification of the susceptor which concerns on one Embodiment of this invention. It is a top view which shows the 2nd modification of the susceptor which concerns on one Embodiment of this invention. It is a top view which shows the 3rd modification of the susceptor which concerns on one Embodiment of this invention. It is a top view which shows the 4th modification of the susceptor which concerns on one Embodiment of this invention. It is sectional drawing which shows the conventional susceptor.

Hereinafter, embodiments of the susceptor and electrostatic chuck device according to the present invention will be described with reference to the drawings. It should be noted that the drawings used in the following description are shown by enlarging the characteristic portions for convenience, and the dimensional ratios and the like of each component may differ from the actual ones. Further, the materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately changed without changing the gist thereof.

[Suceptor]
FIG. 1 is a cross-sectional view showing a susceptor of the present embodiment. As shown in FIG. 1, the susceptor 1 of the present embodiment is in contact with the pair of ceramic plates 2 and 3 containing a conductive substance, the electrode 4 interposed between the pair of ceramic plates 2 and 3, and the electrode 4. The power supply terminal 5 is provided so as to penetrate the ceramic plate 2.
Hereinafter, the ceramic plate 2 is referred to as a first ceramic plate 2, and the ceramic plate 3 is referred to as a second ceramic plate 3.
As shown in FIG. 1, in the susceptor 1, the first ceramic plate 2, the electrode 4, and the second ceramic plate 3 are laminated in this order. That is, the susceptor 1 is a joined body in which the first ceramic plate 2 and the second ceramic plate 3 are joined and integrated via the electrode 4.

As shown in FIG. 1, the second ceramic plate 3 has a mounting surface 3a on which a sample (not shown) is placed. That is, the mounting surface 3a is the surface (upper surface) of the second ceramic plate 3 opposite to the electrode 4.

As shown in FIG. 1, the susceptor 1 of the present embodiment feeds power on a surface opposite to the mounting surface 3a, that is, a surface (lower surface) 2a opposite to the electrode 4 in the first ceramic plate 2. It includes a terminal 5 and has a recess 6 recessed on the mounting surface 3a side. In the susceptor 1 of the present embodiment, the recess 6 is formed only in the power feeding terminal 5. Further, the inner surface 6a (opening) of the recess 6 is formed up to the boundary between the first ceramic plate 2 and the power feeding terminal 5. Further, the cross-sectional shape of the inner surface 6a of the recess 6 in the thickness direction of the ceramic plates 2 and 3 is preferably a curved shape or a hyperbolic shape represented by at least one curvature or a quadratic function. That is, the cross-sectional shape of the inner surface 6a of the recess 6 may be a curved shape represented by one or two or more curvatures, or may be a hyperbolic shape. Specific examples of the cross-sectional shape of the inner surface 6a of the recess 6 include an arc shape or an arc shape shown in FIG.

The shape and size of the inner surface 6a of the recess 6 are not particularly limited, but as shown in FIG. 1, the shape and size of the tip portion 31A of the connection portion 31 of the electrode pin 30 which is pressed against the power supply terminal 5 and connected. It is adjusted as appropriate according to the above. The shape of the inner surface 6a of the recess 6 is, for example, a shape along the outer diameter 31a of the tip portion 31A. As a result, even if the electrode pin 30 is tilted with respect to the power feeding terminal 5, a sufficient contact area between the inner surface 6a of the recess 6 and the tip portion 31A of the electrode pin 30 is sufficiently secured, and changes in these contact areas are suppressed. Can be done.

The first ceramic plate 2 and the second ceramic plate 3 have the same shape of their overlapping surfaces.
The thicknesses of the first ceramic plate 2 and the second ceramic plate 3 are not particularly limited, and are appropriately adjusted according to the use of the ceramic joint 1.

The first ceramic plate 2 and the second ceramic plate 3 have the same composition or the same main component. The first ceramic plate 2 and the second ceramic plate 3 are made of a composite of an insulating substance and a conductive substance.

The insulating material contained in the first ceramic plate 2 and the second ceramic plate 3 is not particularly limited, and is, for example, aluminum oxide (Al ₂ O ₃ ), aluminum nitride (Al N), yttrium oxide (Y ₂ O _3). ), Yttrium aluminum garnet (YAG) and the like.

The conductive material contained in the first ceramic plate 2 and the second ceramic plate 3 is not particularly limited, and is, for example, silicon carbide (SiC), titanium oxide (TIO ₂ ), titanium nitride (TiN), titanium carbide ( Examples thereof include TiC), carbon (C), carbon nanotube (CNT), carbon nanofibers, rare earth oxides, and rare earth fluorides.

The materials of the first ceramic plate 2 and the second ceramic plate 3 have a volume resistivity of 10 ¹³ Ω · cm or more and 10 ¹⁵ Ω · cm or less, have mechanical strength, and are corrosive. It is not particularly limited as long as it has durability against gas and its plasma. Examples of such a material include an aluminum oxide (Al ₂ O ₃ ) sintered body, an aluminum nitride (AlN) sintered body, an aluminum oxide (Al ₂ O ₃ ) -silicon carbide (SiC) composite sintered body, and the like. However, from the viewpoint of dielectric properties at high temperature, high corrosion resistance, plasma resistance, and heat resistance, an aluminum oxide (Al ₂ O ₃ ) -silicon carbide (SiC) composite sintered body is preferable.

The average primary particle diameters of the insulating substances constituting the first ceramic plate 2 and the second ceramic plate 3 are preferably 0.5 μm or more and 3.0 μm or less, and 1.0 μm or more and 2.0 μm or less. Is more preferable.
When the average primary particle diameter of the insulating substances constituting the first ceramic plate 2 and the second ceramic plate 3 is 0.5 μm or more and 3.0 μm or less, the first ceramic plate 2 is dense, has high withstand voltage resistance, and has high durability. The ceramic plate 2 of 1 and the second ceramic plate 3 can be obtained.

The method for measuring the average primary particle size of the insulating substance constituting the first ceramic plate 2 and the second ceramic plate 3 is as follows. With an electrolytic emission scanning electron microscope (FE-SEM) manufactured by JEOL Ltd., the cut surfaces of the first ceramic plate 2 and the second ceramic plate 3 in the thickness direction were observed, and 200 insulating substances were observed by the intercept method. Let the average particle size be the average primary particle size.

The electrode 4 is a plasma generation electrode for energizing high-frequency power to generate plasma and performing plasma processing, an electrostatic chuck electrode for generating electric charge and fixing a plate-shaped sample by electrostatic attraction, and energization. It is used as a heater electrode or the like for heating a plate-shaped sample by generating heat. The shape of the electrode 4 (the shape when the electrode 4 is viewed in a plane (viewed from the thickness direction)) and the size (the thickness and the area when the electrode 4 is viewed in a plane (viewed from the thickness direction)) are , Is not particularly limited, and is appropriately adjusted according to the use of the susceptor 1.

The electrode 4 is a composite of an insulating substance and a conductive substance.

The insulating substance contained in the electrode 4 is not particularly limited, and is, for example, aluminum oxide (Al ₂ O ₃ ), aluminum nitride (Al N _{), silicon nitride (Si 3 N 4} ), yttrium oxide (III) (Y ₂ O). ₃ ), at least one selected from the group consisting of yttrium aluminum garnet (YAG) and SmAlO _{3 is preferable.} The insulating substance contained in the electrode 4 is preferably matched with the main components of the first ceramic plate 2 and the second ceramic plate 3.
Since the electrode 4 is made of a conductive substance and an insulating substance, the bonding strength between the first ceramic plate 2 and the second ceramic plate 3 and the mechanical strength as an electrode are increased.
Since the insulating substance contained in the electrode 4 is aluminum oxide (Al ₂ O ₃ ), the dielectric property at high temperature, high corrosion resistance, plasma resistance, and heat resistance are maintained.

Conductive material contained in the electrode 4, molybdenum carbide _(Mo 2 C), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC) , Carbon black, preferably at least one selected from the group consisting of carbon nanotubes and carbon nanofibers. When the conductive substance contained in the electrode 4 is at least one selected from the group consisting of the substances, the conductivity of the conductive layer can be ensured.

The ratio (blending ratio) of the contents of the insulating substance and the conductive substance in the electrode 4 is not particularly limited, and is appropriately adjusted according to the use of the susceptor 1.

The power feeding terminal 5 supplies a current to the electrode 4. The shape of the power supply terminal 5 (the shape when the power supply terminal 5 is viewed in a plane (viewed from the thickness direction)) and the size (the thickness and the shape when the power supply terminal 5 is viewed in a plane (viewed from the thickness direction)) The area) is not particularly limited, and is appropriately adjusted according to the use of the susceptor 1.

The power feeding terminal 5 is a composite of an insulating substance and a conductive substance.

The insulating substance contained in the power feeding terminal 5 is the same as the insulating substance contained in the electrode 4.
The conductive substance contained in the power feeding terminal 5 is the same as the conductive substance contained in the electrode 4.

The ratio (blending ratio) of the content of the insulating substance and the conductive substance in the power feeding terminal 5 is not particularly limited and is appropriately adjusted according to the use of the susceptor 1. For example, the content of the conductive substance is 45. It is preferably 5% by mass or more and 75% by mass or less, more preferably 50% by mass or more and 70% by mass or less, and more preferably 55% by mass or more and 65% by mass or less. When the content of the conductive substance is 45% by mass or more and 75% by mass or less, a sufficient current can be supplied to the electrode 4, and the strength as a feeding terminal can also be obtained.

According to the susceptor 1 of the present embodiment, since the surface opposite to the mounting surface 3a includes the feeding terminal 5 and has the recess 6 recessed on the mounting surface 3a side, the ceramic plates 2, 3, the electrodes 4, etc. Even if the electrode pin 30 is tilted with respect to the feeding terminal 5 due to the shear stress caused by the difference in the coefficient of linear expansion of the above, it is possible to suppress the change in the contact area between the feeding terminal 5 and the electrode pin 30. Further, if the cross-sectional shape of the inner surface 6a of the recess 6 in the thickness direction of the ceramic plates 2 and 3 is a curved shape or a hyperbola represented by at least one curvature or a quadratic function, the ceramic plates 2 and 3 and the electrode 4 Even if the electrode pin 30 is tilted with respect to the feeding terminal 5 due to shear stress caused by the difference in linear expansion rate such as, the effect of suppressing the change in the contact area between the feeding terminal 5 and the electrode pin 30 is further improved. do.

In the present embodiment, the case where the first ceramic plate 2 and the second ceramic plate 3 are separate bodies is illustrated, but the susceptor according to the present invention is not limited to this. In the susceptor according to the present invention, the first ceramic plate and the second ceramic plate may be integrated and an electrode may be provided inside the first ceramic plate.

[Manufacturing method of susceptor]
Hereinafter, the method for producing the susceptor of the present embodiment will be described with reference to FIG.

An electrode-forming paste is applied to the upper surface 2b of the first ceramic plate 2 by a coating method such as a screen printing method to form a coating film (electrode coating film) to be the electrode 4.
As the electrode-forming paste, a paste in which an insulating substance and a conductive substance forming the electrode 4 are dispersed in a solvent is used.
Isopropyl alcohol or the like is used as the solvent contained in the electrode forming pace.

Next, the second ceramic plate 3 is laminated so that the lower surface 3b of the second ceramic plate 3 is in contact with the surface of the electrode coating film on the side opposite to the surface in contact with the first ceramic plate 2.

Next, a through hole 2A extending from the lower surface 2a to the electrode 4 is formed in the second ceramic plate 3 by, for example, drilling with a diamond drill, laser machining, electric discharge machining, ultrasonic machining, or the like.

Next, a paste for forming a power feeding terminal is applied into the through hole 2A by a coating method such as a screen printing method to form a coating film (conductive coating film) serving as the power feeding terminal 5.
As the feed terminal forming paste, a paste in which an insulating substance and a conductive substance forming the power supply terminal 5 are dispersed in a solvent is used.
Isopropyl alcohol or the like is used as the solvent contained in the pace for forming the feeding terminal.

Next, the laminate including the first ceramic plate 2, the coating film serving as the electrode 4, the coating film serving as the power feeding terminal 5, and the second ceramic plate 3 is pressed in the thickness direction while being heated. The atmosphere when the laminate is pressurized in the thickness direction while being heated is preferably a vacuum or an inert atmosphere such as _{Ar, He, N 2.}

The temperature for heating the laminate (heat treatment temperature) is preferably 1600 ° C. or higher and 1900 ° C. or lower, and more preferably 1650 ° C. or higher and 1850 ° C. or lower.
When the temperature for heating the laminate is 1600 ° C. or higher and 1900 ° C. or lower, the solvent contained in each coating film is volatilized, and the electrode 4 is placed between the first ceramic plate 2 and the second ceramic plate 3. Can be formed. Further, the first ceramic plate 2 and the second ceramic plate 3 can be joined and integrated via the electrode 4.

The pressure (pressurizing pressure) for pressurizing the laminated body in the thickness direction is preferably 1.0 MPa or more and 50.0 MPa or less, and more preferably 5.0 MPa or more and 20.0 MPa or less.
When the pressure for pressurizing the laminate in the thickness direction is 1.0 MPa or more and 50.0 MPa or less, the electrode 4 can be formed between the first ceramic plate 2 and the second ceramic plate 3. Further, the first ceramic plate 2 and the second ceramic plate 3 can be joined and integrated via the electrode 4.

Next, a recess 6 including a power supply terminal 5 and recessed on the mounting surface 3a side is formed on the lower surface 2a of the first ceramic plate 2 by a laser machining method, an electric discharge machining method, an ultrasonic machining method, or the like, and the susceptor 1 is formed. To get.

[Electrostatic chuck device]
Hereinafter, the electrostatic chuck device according to the embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a cross-sectional view showing the electrostatic chuck device of the present embodiment. In FIG. 2, the same components as those of the ceramic joint shown in FIG. 1 are designated by the same reference numerals, and redundant description will be omitted.
As shown in FIG. 2, the electrostatic chuck device 100 of the present embodiment includes a disk-shaped electrostatic chuck member 102 and a disk-shaped temperature control base member that adjusts the electrostatic chuck member 102 to a desired temperature. It has 103, and an adhesive layer 104 that joins and integrates the electrostatic chuck member 102 and the temperature adjusting base member 103. In the electrostatic chuck device 100 of the present embodiment, the electrostatic chuck member 102 includes, for example, the susceptor 1 of the above-described embodiment. Here, a case where the electrostatic chuck member 102 is composed of the susceptor 1 will be described.
In the following description, the mounting surface 111a side of the mounting plate 111 may be referred to as "upper" and the temperature adjusting base member 103 side may be referred to as "lower" to represent the relative positions of each configuration.

[Electrostatic chuck member]
The electrostatic chuck member 102 has a mounting plate 111 whose upper surface is made of ceramics having a mounting surface 111a on which a plate-shaped sample such as a semiconductor wafer is mounted, and a surface opposite to the mounting surface 111a of the mounting plate 111. The support plate 112 provided on the side, the electrostatic adsorption electrode 113 sandwiched between the mounting plate 111 and the support plate 112, and the electrostatic adsorption electrode 113 sandwiched between the mounting plate 111 and the support plate 112 for electrostatic adsorption. An annular insulating material 114 surrounding the electrode 113, a power supply terminal 116 provided in a through hole 115 of the support plate 112 so as to be in contact with the electrostatic adsorption electrode 113, and a fixing hole 117 of the temperature control base member 103. It has an electrode pin 118 provided inside.
In the electrostatic chuck member 102, the mounting plate 111 corresponds to the second ceramic plate 3, the support plate 112 corresponds to the first ceramic plate 2, and the electrostatic adsorption electrode 113 corresponds to the electrode. The power supply terminal 116 corresponds to the above-mentioned power supply terminal 5, and the electrode pin 118 corresponds to the electrode pin 30.

[Mounting board]
A large number of protrusions for supporting a plate-shaped sample such as a semiconductor wafer are erected on the mounting surface 111a of the mounting plate 111 (not shown). Further, on the peripheral edge of the mounting surface 111a of the mounting plate 111, an annular protrusion having a quadrangular cross section is provided so as to go around the peripheral edge so that cooling gas such as helium (He) does not leak. You may be. Further, in the region surrounded by the annular protrusions on the mounting surface 111a, a plurality of protrusions having the same height as the annular protrusions, having a circular cross section and a substantially rectangular vertical cross section are provided. You may be.

The thickness of the mounting plate 111 is preferably 0.3 mm or more and 3.0 mm or less, and more preferably 0.5 mm or more and 1.5 mm or less. When the thickness of the mounting plate 111 is 0.3 mm or more, the withstand voltage resistance is excellent. On the other hand, if the thickness of the mounting plate 111 is 3.0 mm or less, the electrostatic attraction force of the electrostatic chuck member 102 does not decrease, and the plate is mounted on the mounting surface 111a of the mounting plate 111. The temperature of the plate-shaped sample being processed can be maintained at a preferable constant temperature without reducing the thermal conductivity between the shaped sample and the temperature adjusting base member 103.

[Support plate]
The support plate 112 supports the mounting plate 111 and the electrostatic adsorption electrode 113 from below.

The thickness of the support plate 112 is preferably 0.3 mm or more and 3.0 mm or less, and more preferably 0.5 mm or more and 1.5 mm or less. If the thickness of the support plate 112 is 0.3 mm or more, a sufficient withstand voltage can be secured. On the other hand, if the thickness of the support plate 112 is 3.0 mm or less, the electrostatic attraction force of the electrostatic chuck member 102 does not decrease, and the plate shape is mounted on the mounting surface 111a of the mounting plate 111. The temperature of the plate-shaped sample being processed can be maintained at a preferable constant temperature without reducing the thermal conductivity between the sample and the temperature adjusting base member 103.

[Electrode for electrostatic adsorption]
In the electrostatic adsorption electrode 113, by applying a voltage, an electrostatic adsorption force for holding the plate-shaped sample on the mounting surface 111a of the mounting plate 111 is generated.

The thickness of the electrostatic adsorption electrode 113 is preferably 5 μm or more and 200 μm or less, and more preferably 10 μm or more and 100 μm or less. When the thickness of the electrostatic adsorption electrode 113 is 5 μm or more, sufficient conductivity can be ensured. On the other hand, if the thickness of the electrostatic adsorption electrode 113 is 200 μm or less, the thermal conductivity between the plate-shaped sample mounted on the mounting surface 111a of the mounting plate 111 and the temperature adjusting base member 3 is high. The temperature of the plate-shaped sample being processed can be maintained at a desired constant temperature without lowering. In addition, plasma permeability can be stably generated without deterioration.

[Insulating material]
The insulating material 114 surrounds the electrostatic adsorption electrode 113 and protects the electrostatic adsorption electrode 113 from corrosive gas and its plasma.
The mounting plate 111 and the support plate 112 are joined and integrated by the insulating material 114 via the electrostatic adsorption electrode 113.

The insulating material 114 is provided to join the boundary portion between the mounting plate 111 and the support plate 112, that is, the outer edge portion region other than the electrostatic adsorption electrode 113 forming portion. The shape of the insulating material 114 (the shape when the insulating material 114 is viewed in a plan view (viewed from the thickness direction)) is not particularly limited, and is appropriately adjusted according to the shape of the electrostatic adsorption electrode 113.
In the electrostatic chuck device 100 of the present embodiment, the thickness of the insulating material 114 is equal to the thickness of the electrostatic adsorption electrode 113.

The insulating material 114 is made of an insulating substance.
The insulating material constituting the insulating material 114 is not particularly limited, but is preferably the same as the main components of the mounting plate 111 and the support plate 112, for example, aluminum oxide (Al ₂ O ₃ ) and aluminum nitride (Al N). ), Yttrium oxide (Y ₂ O ₃ ), yttrium aluminum garnet (YAG) and the like. The insulating substance constituting the insulating material 114 is preferably _{aluminum oxide (Al 2} O _3). Since the insulating substance constituting the insulating material 114 is aluminum oxide (Al ₂ O ₃ ), the dielectric property at high temperature, high corrosion resistance, plasma resistance, and heat resistance are maintained.

The average primary particle size of the insulating substance constituting the insulating material 114 is preferably 1.6 μm or more and 10.0 μm or less, and more preferably 1.6 μm or more and 6.0 μm or less.
When the average primary particle size of the insulating substance constituting the insulating material 114 is 1.6 μm or more, sufficient withstand voltage resistance can be obtained. On the other hand, when the average primary particle size of the insulating substance constituting the insulating material 114 is 10.0 μm or less, the processability such as grinding is good.

The method for measuring the average primary particle size of the insulating substance constituting the insulating material 114 is the same as the method for measuring the average primary particle size of the insulating substance constituting the mounting plate 111 and the support plate 112.

[Power supply terminal]
The power feeding terminal 116 supplies a current to the electrostatic adsorption electrode 113.
The number, shape, and the like of the feeding terminals 116 are determined by the form of the electrostatic adsorption electrode 113, that is, whether it is a unipolar type or a bipolar type.

[Electrode pin]
The electrode pin 118 supplies a current to the feeding terminal 116. The electrode pin 118 has a structure similar to that of the electrode pin 30 shown in FIG. 1, for example. The electrode pin 30 has a connecting portion 31 that is pressed against and connected to the power feeding terminal 5, and a spring 32 that is provided on the side of the connecting portion 31 opposite to the tip portion 31A. The power supply terminal 116 and the electrode pin 118 are connected by pressing the tip portion 31A against the power supply terminal 116 by the elastic force of the spring 32.

[Temperature adjustment base member]
The temperature adjusting base member 103 is a thick disk made of at least one of metal and ceramics. The skeleton of the temperature adjusting base member 103 is configured to also serve as an internal electrode for plasma generation. Inside the skeleton of the temperature adjusting base member 103, a flow path 121 for circulating a cooling medium such as _{water, He gas, N 2 gas, etc. is formed.}

The skeleton of the temperature adjusting base member 103 is connected to an external high frequency power supply 122. Further, in the fixing hole 117 of the temperature adjusting base member 103, an electrode pin 118 whose outer periphery is surrounded by the insulating material 123 is fixed via the insulating material 123. The electrode pin 118 is connected to an external DC power supply 124.

The material constituting the temperature adjusting base member 103 is not particularly limited as long as it is a metal having excellent thermal conductivity, conductivity, and workability, or a composite material containing these metals. As the material constituting the temperature adjusting base member 3, for example, aluminum (Al), copper (Cu), stainless steel (SUS), titanium (Ti) and the like are preferably used.
At least the surface of the temperature adjusting base member 103 exposed to plasma is preferably anodized or resin-coated with a polyimide resin. Further, it is more preferable that the entire surface of the temperature adjusting base member 103 is subjected to the above-mentioned alumite treatment or resin coating.

By applying an alumite treatment or a resin coating to the temperature adjusting base member 103, the plasma resistance of the temperature adjusting base member 103 is improved and abnormal discharge is prevented. Therefore, the plasma resistance stability of the temperature adjusting base member 103 is improved, and the occurrence of surface scratches on the temperature adjusting base member 103 can be prevented.

[Adhesive layer]
The adhesive layer 104 adheres and integrates the electrostatic chuck portion 102 and the cooling base portion 103.

The thickness of the adhesive layer 104 is preferably 100 μm or more and 200 μm or less, and more preferably 130 μm or more and 170 μm or less.
When the thickness of the adhesive layer 104 is within the above range, the adhesive strength between the electrostatic chuck portion 102 and the cooling base portion 103 can be sufficiently maintained. Further, it is possible to sufficiently secure the thermal conductivity between the electrostatic chuck portion 102 and the cooling base portion 103.

The adhesive layer 104 is formed of, for example, a cured product obtained by heat-curing a silicone-based resin composition, an acrylic resin, an epoxy resin, or the like.
The silicone-based resin composition is a silicon compound having a siloxane bond (Si—O—Si), and is more preferable because it is a resin having excellent heat resistance and elasticity.

As such a silicone-based resin composition, a silicone resin having a thermosetting temperature of 70 ° C. to 140 ° C. is particularly preferable.
Here, if the thermosetting temperature is lower than 70 ° C., when the electrostatic chuck portion 102 and the cooling base portion 103 are joined in a state of facing each other, the curing does not proceed sufficiently in the joining process, so that workability It is not preferable because it is inferior to. On the other hand, when the heat curing temperature exceeds 140 ° C., the difference in thermal expansion between the electrostatic chuck portion 102 and the cooling base portion 103 is large, and the stress between the electrostatic chuck portion 102 and the cooling base portion 103 increases. , It is not preferable because peeling may occur between them.

According to the electrostatic chuck device 100 of the present embodiment, since the electrostatic chuck member 102 is composed of the susceptor 1, even if the electrode pin 118 is tilted with respect to the power feeding terminal 116, the electrostatic chuck member 102 is placed on the mounting surface 111a. Can sufficiently secure the contact area between the inner surface of the recess including the power feeding terminal 116 provided on the opposite surface and the tip end portion of the electrode pin 118, and suppress the change in these contact areas.

Hereinafter, a method of manufacturing the electrostatic chuck device of this embodiment will be described.

The electrostatic chuck member 102 made of the susceptor 1 obtained as described above is prepared.

An adhesive made of a silicone-based resin composition is applied to a predetermined region of one main surface 103a of the cooling base portion 103. Here, the amount of the adhesive applied is adjusted so that the electrostatic chuck portion 102 and the cooling base portion 103 can be joined and integrated.
Examples of the method for applying this adhesive include a bar coating method, a screen printing method, and the like, in addition to manually applying the adhesive using a spatula or the like.

After applying the adhesive to one main surface 103a of the cooling base portion 103, the electrostatic chuck portion 102 and the cooling base portion 103 coated with the adhesive are overlapped with each other.
Further, the electrode pin 118 is inserted into and fitted into the fixing hole 117 formed in the cooling base portion 103.
Next, the electrostatic chuck portion 102 is pressed against the cooling base portion 103 with a predetermined pressure to join and integrate the electrostatic chuck portion 102 and the cooling base portion 103. As a result, the electrostatic chuck portion 102 and the cooling base portion 103 are joined and integrated via the adhesive layer 104.

As described above, the electrostatic chuck device 100 of the present embodiment is obtained in which the electrostatic chuck portion 102 and the cooling base portion 103 are joined and integrated via the adhesive layer 104.

The plate-shaped sample according to the present embodiment is not limited to a semiconductor wafer, and is, for example, a glass substrate for a flat plate display (FPD) such as a liquid crystal display (LCD), a plasma display (PDP), or an organic EL display. It may be. Further, the electrostatic chuck device of the present embodiment may be designed according to the shape and size of the substrate.

[Other Embodiments]
The present invention is not limited to the above embodiment.

For example, the susceptors 200, 300, 400, and 500 according to the first modification to the fourth modification as shown in FIGS. 3 to 6 may be adopted. In the susceptors 200, 300, 400, and 500 according to the first modification to the fifth modification, the same parts as the components in the embodiment are designated by the same reference numerals, the description thereof is omitted, and the differences are different. Will be described only.

The susceptor 200 of the first modification shown in FIG. 3 includes a power feeding terminal 5 and a first ceramic plate 2 on the lower surface 2a of the first ceramic plate 2, and has a recess 6 recessed on the mounting surface 3a side. That is, the inner surface 6a of the recess 6 is formed of a central portion 6A including the power feeding terminal 5 and an outer edge portion 6B along the outer edge of the central portion 6A. As a result, even if the inclination (deviation) of the electrode pin 30 with respect to the power feeding terminal 5 becomes large, a sufficient contact area between the inner surface 6a of the recess 6 and the tip portion 31A of the electrode pin 30 is sufficiently secured, and the contact area changes. Can be suppressed.

The susceptor 300 of the second modification shown in FIG. 4 includes a power feeding terminal 5 on the lower surface 2a of the first ceramic plate 2 and has a recess 6 recessed on the mounting surface 3a side. In the susceptor 300 of this modification, the recess 6 is formed only in the power feeding terminal 5, and the inner surface 6a (opening) of the recess 6 does not reach the boundary between the first ceramic plate 2 and the feeding terminal 5. As a result, the inclination (deviation) of the electrode pin 30 with respect to the power feeding terminal 5 is reduced, a sufficient contact area between the inner surface 6a of the recess 6 and the tip portion 31A of the electrode pin 30 is sufficiently secured, and the change in these contact areas is changed. It can be suppressed.

The susceptor 400 of the third modification shown in FIG. 5 includes a power feeding terminal 5 and a first ceramic plate 2 on the lower surface 2a of the first ceramic plate 2, and has a recess 6 recessed on the mounting surface 3a side. Further, the susceptor 400 has a metal layer 410 that covers the inner surface 6a of the recess 6. In the susceptor 400 of the present modification, the metal layer 410 is formed along the inner surface 6a of the recess 6, and the metal layer 410 has a recess 411 recessed toward the mounting surface 3a. Further, the cross-sectional shape of the inner surface 411a of the recess 411 in the thickness direction of the first ceramic plate 2 is preferably a curved shape or a hyperbolic shape represented by at least one curvature or a quadratic function.

The metal layer 410 is made of a conductive substance. The conductive substance constituting the metal layer 410 is not particularly limited, and examples thereof include Ag, Cu, In, Ti, Sn, etc., which may be used alone or in combination. ..

The arithmetic mean roughness (Ra) of the surface of the metal layer 410 opposite to the inner surface 6a of the recess 6 (inner surface 411a of the recess 411) is preferably 2 μm or more and 30 μm or less, and more preferably 4 μm or more and 25 μm or less. It is preferably 6 μm or more and 20 μm or less, more preferably.
When the arithmetic mean roughness (Ra) of the inner surface 411a of the recess 411 is 2 μm or more and 30 μm or less, a sufficient current can be supplied from the power supply pin 30 to the power supply terminal 5, and the wear resistance of the power supply terminal 5 is reduced. be able to.

The arithmetic mean roughness (Ra) of the inner surface 411a of the recess 411 was determined by using a stylus type surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd., JIS B 0601: 2013 "Product Geometric Characteristic Specifications (GPS) -Surface Texture: Contour curve method-Terms, definitions and surface texture parameters ”.

By providing the metal layer 410, it is possible to reduce the resistance due to the connection between the power feeding terminal 5 and the power feeding pin 30 and improve the continuity thereof.

The susceptor 500 of the fourth modification shown in FIG. 6 includes only the power feeding terminal 5 on the lower surface 2a of the first ceramic plate 2, and has a recess 6 recessed on the mounting surface 3a side. Further, the susceptor 400 has a metal layer 510 that covers the inner surface 6a of the recess 6. In the susceptor 500 of the present modification, the metal layer 510 is formed along the inner surface 6a of the recess 6, and the metal layer 510 has a recess 511 recessed toward the mounting surface 3a. Further, the cross-sectional shape of the inner surface 511a of the recess 511 in the thickness direction of the first ceramic plate 2 is preferably a curved shape or a hyperbolic shape represented by at least one curvature or a quadratic function. The metal layer 510 is made of a conductive substance. Examples of the conductive substance constituting the metal layer 510 include the same conductive substances as those constituting the metal layer 410. By providing the metal layer 510, it is possible to reduce the resistance due to the connection between the power supply terminal 5 and the power supply pin 30 and improve the continuity thereof.

Since the susceptor of the present invention includes a feeding terminal on the surface opposite to the mounting surface and has a recessed recess on the mounting surface side, shear stress due to the difference in linear expansion rate of the ceramic plate, electrodes, etc. is generated. Even if the electrode pin is tilted with respect to the power feeding terminal, the change in the contact area between the power feeding terminal and the electrode pin can be suppressed. Therefore, it is suitably used as an electrostatic chuck member of an electrostatic chuck device. , Its usefulness is very great.

1 Suceptor 2 Ceramic plate (first ceramic plate)
3 Ceramic plate (second ceramic plate)
4 Electrode 5 Power supply terminal 6 Recession 30 Electrode pin 100 Electrostatic chuck device 102 Electrostatic chuck member 103 Temperature adjustment base member 104 Adhesive layer 111 Mounting plate 112 Support plate 113 Electrostatic adsorption electrode 114 Insulation material 115 Through hole 116 Power supply terminal 117 Fixed hole 118 Electrode pin 121 Flow path 122 High frequency power supply 123 Insulation material 124 DC power supply

Claims (8)

It is provided with an electrode provided inside a ceramic plate having a mounting surface on which a sample is placed, and a feeding terminal provided through the ceramic plate so as to be in contact with the electrode.
A susceptor having a recess on the surface opposite to the previously described mounting surface, including at least the power feeding terminal and having a recess on the previously described mounting surface side. The susceptor according to claim 1, wherein the cross-sectional shape of the inner surface of the recess in the thickness direction of the ceramic plate is a curved shape or a hyperbolic shape represented by at least one curvature or a quadratic function. The susceptor according to claim 2, further comprising a metal layer covering the inner surface. The susceptor according to claim 3, wherein the arithmetic mean roughness (Ra) of the surface of the metal layer opposite to the inner surface is 2 μm or more and 30 μm or less. The susceptor according to any one of claims 1 to 4, wherein the electrode and the feeding terminal are a composite of an insulating substance and a conductive substance. The susceptor according to claim 5, wherein the insulating substance is at least one selected from the group consisting of aluminum oxide, aluminum nitride, silicon nitride, yttrium oxide (III), yttrium aluminum garnet and SmAlO _3. The conductive substance is _{at least one selected from the group consisting of Mo 2} C, Mo, WC, W, TaC, Ta, SiC, carbon black, carbon nanotubes and carbon nanofibers, according to claim 5 or 6. The susceptor according to any one item. An electrostatic chuck device in which an electrostatic chuck member made of ceramics and a temperature control base member made of metal are joined via an adhesive layer.
The electrostatic chuck member is an electrostatic chuck device comprising the susceptor according to any one of claims 1 to 7.

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