Electrostatic Chuck Device

Abstract

To provide a susceptor in which, change in a contact area between a power supply terminal and an electrode pin can be suppressed even when shear stress due to the difference in linear expansion coefficients of a mounting plate, a support plate, an internal electrode, etc. acts on the connection portion of the power supply terminal and the electrode pin, and to provide an electrostatic chuck device including the susceptor.SOLUTION: A susceptor 1 is provided, including an electrode 4 provided inside a ceramic plate 3 having a mounting surface 3a on which a sample is mounted, and a power supply terminal 5 provided penetrating through a ceramic plate 2 in such a way that the power supply terminal 5 comes in contact with the electrode 4, and the susceptor 1 furthermore includes: at least the power supply terminal 5 in a surface opposite to the mounting surface 3a; and a recessed portion 6 recessed toward the mounting surface 3a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a susceptor and an electrostatic chuck device. [Background technology]

[0002] In recent years, dry etching equipment and CVD equipment used in the manufacturing process of semiconductors such as ICs, LSIs, and VLSIs have been shifting to single-wafer processing, in which plate-like samples such as semiconductor wafers, LCD glass substrates, and printed circuit boards are processed one by one in order to perform uniform etching or CVD film formation on each wafer.In this single-wafer process, plate-like samples are placed on a sample stage (base) called a susceptor to hold each sample in the processing chamber and undergo the specified processing. Since the susceptor must be able to withstand use in plasma and at high temperatures, it is required to have excellent plasma resistance and high thermal conductivity. As such a susceptor, a susceptor made of a ceramic sintered body, which has excellent plasma resistance and thermal conductivity, is used.

[0003] Some susceptors are provided with internal electrodes, such as an electrostatic chuck electrode for generating an electric charge inside the susceptor to fix a plate-shaped sample by electrostatic adsorption, a heater electrode for heating the plate-shaped sample by passing electricity through it to generate heat, and a plasma generation electrode for generating plasma by passing high-frequency power through it to perform plasma processing (see, for example, Patent Document 1).

[0004] Fig. 7 is a cross-sectional view showing an example of a susceptor having such an internal electrode built in. The susceptor 600 shown in Fig. 7 includes a mounting plate 601 on which a plate-shaped sample (not shown) is placed, a support plate 602 that supports the mounting plate 601, an internal electrode 603 that is sandwiched and held between the mounting plate 601 and the support plate 602, and power supply terminals 604, 604 that are embedded in the support plate 602 so as to be in contact with the internal electrode 603 and that supply current to the internal electrode 603.

[0005] 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 current to the power supply terminal (see, for example, Patent Document 2). This connection structure is effective in alleviating shear stress that is applied to the connection between the power supply terminal and the electrode pin due to differences in the linear expansion coefficients of the mounting plate, support plate, internal electrode, etc. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3746935 [Patent Document 2] Patent No. 6228031 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the connection structure of Patent Document 2, the electrode pin is pressed against the planar power supply terminal. Therefore, when shear stress is applied to the connection portion due to differences in the linear expansion coefficients of the mounting plate, support plate, internal electrode, etc., the electrode pin tilts relative to the power supply terminal, changing the contact area between the power supply terminal and the electrode pin, which poses a problem in that a predetermined amount of current cannot be supplied from the electrode pin to the power supply terminal.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a susceptor and an electrostatic chuck device including a susceptor that can suppress a change in the contact area between a power supply terminal and an electrode pin even if a shear stress resulting from a difference in the linear expansion coefficients of a mounting plate, a support plate, an internal electrode, etc. is applied and the electrode pin is tilted relative to the power supply terminal. [Means for solving the problem]

[0009] In order to solve the above problems, one aspect of the present invention provides a susceptor comprising an electrode provided inside a ceramic plate having a mounting surface on which a sample is placed, and a power supply terminal provided through the ceramic plate so as to contact the electrode, the susceptor having a recess on the surface opposite the mounting surface that includes at least the power supply terminal and is recessed toward the mounting surface.

[0010] 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 a curved or hyperbolic shape expressed by at least one curvature or a quadratic function.

[0011] In one aspect of the present invention, the inner surface may be coated with a metal layer.

[0012] 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.

[0013] In one aspect of the present invention, the electrodes and the power supply terminals may be composites of an insulating material and a conductive material.

[0014] In one aspect of the present invention, the insulating material may be at least one selected from the group consisting of aluminum oxide, aluminum nitride, silicon nitride, yttrium (III) oxide, yttrium aluminum garnet, and SmAlO3.

[0015] In one aspect of the present invention, the conductive material may be at least one selected from the group consisting of Mo2C, Mo, WC, W, TaC, Ta, SiC, carbon black, carbon nanotubes, and carbon nanofibers.

[0016] One aspect of the present invention provides an electrostatic chuck device comprising an electrostatic chuck member made of ceramic and a temperature adjustment base member made of metal bonded together via an adhesive layer, wherein the electrostatic chuck member is a susceptor according to one aspect of the present invention. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a susceptor that can suppress a change in the contact area between the power supply terminal and the electrode pin even when a shear stress resulting from a difference in the linear expansion coefficients of a mounting plate, a support plate, an internal electrode, etc. is applied and the electrode pin is tilted relative to the power supply terminal, and an electrostatic chuck device including the susceptor is also provided. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a cross-sectional view showing a susceptor according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing an electrostatic chuck device according to an embodiment of the present invention. [Figure 3] FIG. 2 is a plan view showing a first modified example of a susceptor according to an embodiment of the present invention. [Figure 4] FIG. 10 is a plan view showing a second modified example of a susceptor according to an embodiment of the present invention. [Figure 5] FIG. 10 is a plan view showing a third modified example of a susceptor according to an embodiment of the present invention. [Figure 6] FIG. 10 is a plan view showing a fourth modified example of a susceptor according to an embodiment of the present invention. [Figure 7] FIG. 1 is a cross-sectional view showing a conventional susceptor. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of a susceptor and an electrostatic chuck device according to the present invention will be described with reference to the drawings. Note that the drawings used in the following description show characteristic portions in an enlarged scale for convenience, and the dimensional ratios of the components may differ from the actual ones. Furthermore, the materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not limited thereto and may be appropriately changed within the scope of the present invention.

[0020] [Susceptor] Fig. 1 is a cross-sectional view showing a susceptor of this embodiment. As shown in Fig. 1, the susceptor 1 of this embodiment includes a pair of ceramic plates 2 and 3 containing a conductive material, an electrode 4 interposed between the pair of ceramic plates 2 and 3, and a power supply terminal 5 provided to penetrate the ceramic plate 2 so as to contact the electrode 4. Hereinafter, the ceramic plate 2 will be referred to as the first ceramic plate 2 and the ceramic plate 3 as the second ceramic plate 3. 1, the susceptor 1 is formed by laminating a first ceramic plate 2, an electrode 4, and a second ceramic plate 3 in this order. That is, the susceptor 1 is a bonded body in which the first ceramic plate 2 and the second ceramic plate 3 are bonded together via the electrode 4.

[0021] 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.

[0022] As shown in FIG. 1 , the susceptor 1 of this embodiment has a recess 6 recessed toward the mounting surface 3a, including the power supply terminal 5, on the surface (lower surface) 2a of the first ceramic plate 2 opposite the electrode 4. In the susceptor 1 of this embodiment, the recess 6 is formed only in the power supply terminal 5. The inner surface 6a (opening) of the recess 6 extends to the boundary between the first ceramic plate 2 and the power supply terminal 5. Furthermore, 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 or 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 or hyperbolic shape represented by one or more curvatures. Specific examples of the cross-sectional shape of the inner surface 6a of the recess 6 include the arc or circular arc shape shown in FIG. 1 .

[0023] 1, the shape and size of the inner surface 6a of the recess 6 are appropriately adjusted according to the shape and size of the tip 31A of the connection portion 31 of the electrode pin 30 that is pressed against the power supply terminal 5 for connection. The shape of the inner surface 6a of the recess 6 is, for example, a shape that follows the outer diameter 31a of the tip 31A. This ensures a sufficient contact area between the inner surface 6a of the recess 6 and the tip 31A of the electrode pin 30 even if the electrode pin 30 is tilted with respect to the power supply terminal 5, and makes it possible to suppress changes in this contact area.

[0024] The first ceramic plate 2 and the second ceramic plate 3 have the same shape at the overlapping surfaces. The thicknesses of the first ceramic plate 2 and the second ceramic plate 3 are not particularly limited and may be adjusted appropriately depending on the intended use of the ceramic bonded body 1 .

[0025] The first ceramic plate 2 and the second ceramic plate 3 have the same composition or main component, and are made of a composite of an insulating material and a conductive material.

[0026] The insulating material contained in the first ceramic plate 2 and the second ceramic plate 3 is not particularly limited, but examples thereof include aluminum oxide (Al2O3), aluminum nitride (AlN), yttrium oxide (Y2O3), and yttrium aluminum garnet (YAG).

[0027] The conductive material contained in the first ceramic plate 2 and the second ceramic plate 3 is not particularly limited, but examples thereof include silicon carbide (SiC), titanium oxide (TiO2), titanium nitride (TiN), titanium carbide (TiC), carbon (C), carbon nanotubes (CNT), carbon nanofibers, rare earth oxides, and rare earth fluorides.

[0028] The material of the first ceramic plate 2 and the second ceramic plate 3 has a volume resistivity of 10 13 Ω·cm or more and 10 15 There are no particular limitations on the material, as long as it has a resistivity of about Ω·cm or less, mechanical strength, and durability against corrosive gases and their plasma. Examples of such materials include aluminum oxide (Al2O3) sintered compacts, aluminum nitride (AlN) sintered compacts, and aluminum oxide (Al2O3)-silicon carbide (SiC) composite sintered compacts. However, aluminum oxide (Al2O3)-silicon carbide (SiC) composite sintered compacts are preferred from the viewpoints of dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance.

[0029] The average primary particle size of the insulating material constituting the first ceramic plate 2 and the second ceramic plate 3 is preferably 0.5 μm or more and 3.0 μm or less, and more preferably 1.0 μm or more and 2.0 μm or less. If the average primary particle diameter of the insulating material 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 and the second ceramic plate 3 can be obtained as a dense plate with high voltage resistance and durability.

[0030] The average primary particle size of the insulating material constituting the first ceramic plate 2 and the second ceramic plate 3 was measured as follows: A field emission scanning electron microscope (FE-SEM) manufactured by JEOL Ltd. was used to observe the cross section of the first ceramic plate 2 and the second ceramic plate 3 in the thickness direction, and the average particle size of 200 particles of the insulating material was determined by the intercept method.

[0031] The electrode 4 is used as a plasma generation electrode for generating plasma by passing high-frequency power therethrough for plasma processing, an electrostatic chuck electrode for generating an electric charge to fix a plate-shaped sample by electrostatic attraction, a heater electrode for heating a plate-shaped sample by passing current through it to generate heat, etc. The shape (shape of the electrode 4 when viewed from above (viewed from the thickness direction)) and size (thickness and area of ​​the electrode 4 when viewed from above (viewed from the thickness direction)) of the electrode 4 are not particularly limited and are adjusted appropriately depending on the application of the susceptor 1.

[0032] The electrode 4 is a composite of an insulating material and a conductive material.

[0033] The insulating material contained in electrode 4 is not particularly limited, but is preferably at least one selected from the group consisting of aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), yttrium(III) oxide (Y2O3), yttrium aluminum garnet (YAG), and SmAlO3. The insulating material contained in electrode 4 is preferably matched to the main components of first ceramic plate 2 and second ceramic plate 3. By making the electrode 4 from a conductive material and an insulating material, the bonding strength between the first ceramic plate 2 and the second ceramic plate 3 and the mechanical strength of the electrode are increased. The insulating material contained in the electrode 4 is aluminum oxide (Al2O3), so that the dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance are maintained.

[0034] The conductive material contained in electrode 4 is preferably at least one selected from the group consisting of molybdenum carbide (MoC), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC), carbon black, carbon nanotubes, and carbon nanofibers. When the conductive material contained in electrode 4 is at least one selected from the group consisting of the above materials, the conductivity of the conductive layer can be ensured.

[0035] The ratio (compounding ratio) of the contents of the insulating material and the conductive material in the electrode 4 is not particularly limited, and is adjusted appropriately depending on the application of the susceptor 1.

[0036] The power supply terminal 5 supplies current to the electrode 4. The shape (shape of the power supply terminal 5 when viewed from above (when viewed from the thickness direction)) and size (thickness and area of ​​the power supply terminal 5 when viewed from above (when viewed from the thickness direction)) of the power supply terminal 5 are not particularly limited and are adjusted appropriately depending on the application of the susceptor 1.

[0037] The power supply terminal 5 is a composite of an insulating material and a conductive material.

[0038] The insulating material contained in the power supply terminal 5 is the same as the insulating material contained in the electrode 4 . The conductive material contained in the power supply terminal 5 is the same as the conductive material contained in the electrode 4 .

[0039] The ratio (compounding ratio) of the content of the insulating material to the conductive material in the power supply terminal 5 is not particularly limited and is adjusted appropriately depending on the application of the susceptor 1, but for example, the content of the conductive material is preferably 45% by mass or more and 75% by mass or less, more preferably 50% by mass or more and 70% by mass or less, and even more preferably 55% by mass or more and 65% by mass or less. If the content of the conductive material 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 required for the power supply terminal can also be ensured.

[0040] According to the susceptor 1 of this embodiment, the surface opposite to the mounting surface 3a has a recess 6 including the power supply terminal 5 and recessed toward the mounting surface 3a, so that even if the electrode pin 30 tilts relative to the power supply terminal 5 due to shear stress caused by differences in the linear expansion coefficients of the ceramic plates 2, 3, the electrode 4, etc., the change in the contact area between the power supply terminal 5 and the electrode pin 30 can be suppressed. Furthermore, if the cross-sectional shape of the inner surface 6a of the recess 6 in the thickness direction of the ceramic plates 2, 3 is a curved or hyperbolic shape represented by at least one curvature or a quadratic function, the effect of suppressing the change in the contact area between the power supply terminal 5 and the electrode pin 30 can be further improved, even if the electrode pin 30 tilts relative to the power supply terminal 5 due to shear stress caused by differences in the linear expansion coefficients of the ceramic plates 2, 3, the electrode 4, etc.

[0041] In this embodiment, the first ceramic plate 2 and the second ceramic plate 3 are separate bodies, but the susceptor according to the present invention is not limited to this. The susceptor according to the present invention may be configured such that the first ceramic plate and the second ceramic plate are integrated and an electrode is provided inside the integrated plate.

[0042] [Susceptor manufacturing method] Hereinafter, the method for manufacturing the susceptor of this embodiment will be described with reference to FIG.

[0043] An electrode-forming paste is applied to the upper surface 2b of the first ceramic plate 2 by a coating method such as screen printing, to form a coating film (electrode coating film) that will become the electrode 4. The electrode forming paste is prepared by dispersing an insulating material and a conductive material that form the electrodes 4 in a solvent. The solvent contained in the electrode forming paste is isopropyl alcohol or the like.

[0044] Next, the second ceramic plate 3 is laminated on the surface of the electrode coating film opposite to the surface in contact with the first ceramic plate 2 so that the lower surface 3b of the second ceramic plate 3 is in contact with the surface.

[0045] Next, through holes 2A are formed in the second ceramic plate 3 from its lower surface 2a to the electrode 4 by, for example, drilling with a diamond drill, laser machining, electrical discharge machining, ultrasonic machining or the like.

[0046] Next, a paste for forming a power supply terminal is applied to the through-hole 2A by a coating method such as screen printing, and a coating film (conductive coating film) that will become the power supply terminal 5 is formed. The power supply terminal forming paste is prepared by dispersing an insulating material and a conductive material that form the power supply terminal 5 in a solvent. The solvent contained in the paste for forming the power supply terminal is isopropyl alcohol or the like.

[0047] Next, the laminate including the first ceramic plate 2, the coating film that will become the electrode 4, the coating film that will become the power supply terminal 5, and the second ceramic plate 3 is heated and pressed in the thickness direction. The atmosphere in which the laminate is heated and pressed in the thickness direction is preferably a vacuum or an inert atmosphere such as Ar, He, or N2.

[0048] The temperature to which the laminate is heated (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 to which the laminate is heated is 1600°C or higher and 1900°C or lower, the solvent contained in each coating film can be volatilized to form an electrode 4 between the first ceramic plate 2 and the second ceramic plate 3. In addition, the first ceramic plate 2 and the second ceramic plate 3 can be joined together via the electrode 4.

[0049] The pressure (pressure) applied to the laminate 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 applied to the laminate in the thickness direction is 1.0 MPa or more and 50.0 MPa or less, an electrode 4 can be formed between the first ceramic plate 2 and the second ceramic plate 3. Furthermore, the first ceramic plate 2 and the second ceramic plate 3 can be bonded together via the electrode 4.

[0050] Next, a recess 6 including a power supply terminal 5 and recessed toward the mounting surface 3a is formed on the lower surface 2a of the first ceramic plate 2 by laser machining, electrical discharge machining, ultrasonic machining or the like, to obtain the susceptor 1.

[0051] [Electrostatic chuck device] An electrostatic chuck device according to one embodiment of the present invention will be described below with reference to FIG.

[0052] Fig. 2 is a cross-sectional view showing an electrostatic chuck device according to this embodiment. In Fig. 2, the same components as those in the ceramic bonded body shown in Fig. 1 are denoted by the same reference numerals, and redundant explanations will be omitted. 2, an electrostatic chuck device 100 of this embodiment includes a disk-shaped electrostatic chuck member 102, a disk-shaped temperature adjustment base member 103 that adjusts the electrostatic chuck member 102 to a desired temperature, and an adhesive layer 104 that bonds and integrates the electrostatic chuck member 102 and the temperature adjustment base member 103. In the electrostatic chuck device 100 of this embodiment, the electrostatic chuck member 102 is, for example, the susceptor 1 of the above-described embodiment. Here, a case where the electrostatic chuck member 102 is the susceptor 1 will be described. In the following description, the side of the mounting surface 111a of the mounting plate 111 may be referred to as "upper" and the side of the temperature adjusting base member 103 as "lower" to indicate the relative positions of the respective components.

[0053] [Electrostatic chuck components] The electrostatic chuck member 102 includes a ceramic mounting plate 111 having an upper surface serving as a mounting surface 111a on which a plate-like sample such as a semiconductor wafer is placed, a support plate 112 provided on the surface of the mounting plate 111 opposite the mounting surface 111a, an electrostatic attraction electrode 113 sandwiched between the mounting plate 111 and the support plate 112, an annular insulating member 114 sandwiched between the mounting plate 111 and the support plate 112 and surrounding the electrostatic attraction electrode 113, a power supply terminal 116 provided in a through hole 115 in the support plate 112 so as to be in contact with the electrostatic attraction electrode 113, and an electrode pin 118 provided in a fixing hole 117 in the temperature control base member 103. 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, the electrostatic attraction electrode 113 corresponds to the electrode 4, the power supply terminal 116 corresponds to the power supply terminal 5, and the electrode pin 118 corresponds to the electrode pin 30.

[0054] [Placement plate] A number of protrusions (not shown) for supporting a plate-shaped sample such as a semiconductor wafer are provided on the mounting surface 111a of the mounting plate 111. Furthermore, a circular protrusion with a square cross section may be provided around the periphery of the mounting surface 111a of the mounting plate 111 to prevent leakage of a cooling gas such as helium (He). Furthermore, a plurality of protrusions having the same height as the circular protrusion, a horizontal cross section of which is circular, and a vertical cross section of which is approximately rectangular may be provided in the area surrounded by the circular protrusion on the mounting surface 111a.

[0055] 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. If the thickness of the mounting plate 111 is 0.3 mm or more, it has excellent voltage resistance. On the other hand, if the thickness of the mounting plate 111 is 3.0 mm or less, the electrostatic adsorption force of the electrostatic chuck member 102 is not reduced, and the thermal conductivity between the plate-like sample placed on the mounting surface 111a of the mounting plate 111 and the temperature adjustment base member 103 is not reduced, so that the temperature of the plate-like sample during processing can be maintained at a desired constant temperature.

[0056] [Support plate] The support plate 112 supports the mounting plate 111 and the electrostatic attraction electrode 113 from below.

[0057] 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 ensured. On the other hand, if the thickness of the support plate 112 is 3.0 mm or less, the electrostatic adsorption force of the electrostatic chuck member 102 is not reduced, and the thermal conductivity between the plate-like sample placed on the mounting surface 111a of the mounting plate 111 and the temperature adjustment base member 103 is not reduced, so that the temperature of the plate-like sample during processing can be maintained at a desired constant temperature.

[0058] [Electrostatic adsorption electrode] When a voltage is applied to the electrostatic adsorption electrode 113, an electrostatic adsorption force is generated that holds the plate-shaped sample on the mounting surface 111a of the mounting plate 111.

[0059] The thickness of the electrostatic attraction 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. If the thickness of the electrostatic attraction electrode 113 is 5 μm or more, sufficient conductivity can be ensured. On the other hand, if the thickness of the electrostatic attraction electrode 113 is 200 μm or less, the thermal conductivity between the plate-shaped sample placed on the mounting surface 111a of the mounting plate 111 and the temperature adjustment base member 3 is not reduced, and the temperature of the plate-shaped sample during processing can be maintained at a desired constant temperature. In addition, the plasma permeability is not reduced, and stable plasma can be generated.

[0060] [Insulation material] The insulating material 114 surrounds the electrostatic attraction electrode 113 to protect the electrostatic attraction electrode 113 from corrosive gases and their plasma. The mounting plate 111 and the support plate 112 are joined together by an insulating material 114 via an electrostatic attraction electrode 113 .

[0061] The insulating material 114 is provided to join the boundary between the mounting plate 111 and the support plate 112, i.e., the outer edge region other than the portion where the electrostatic attraction electrode 113 is formed. The shape of the insulating material 114 (the shape of the insulating material 114 when viewed in a plan view (viewed from the thickness direction)) is not particularly limited and is adjusted appropriately depending on the shape of the electrostatic attraction electrode 113. In the electrostatic chuck device 100 of this embodiment, the thickness of the insulating material 114 is equal to the thickness of the electrostatic attraction electrode 113 .

[0062] The insulating material 114 is made of an insulating material. The insulating material constituting the insulating material 114 is not particularly limited, but is preferably the same as the main component of the mounting plate 111 and the support plate 112, and examples thereof include aluminum oxide (Al2O3), aluminum nitride (AlN), yttrium oxide (Y2O3), and yttrium aluminum garnet (YAG). The insulating material constituting the insulating material 114 is preferably aluminum oxide (Al2O3). By using aluminum oxide (Al2O3) as the insulating material constituting the insulating material 114, dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance are maintained.

[0063] The average primary particle size of the insulating material that makes up 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. If the average primary particle size of the insulating material constituting the insulating material 114 is 1.6 μm or more, sufficient voltage resistance can be obtained. On the other hand, if the average primary particle size of the insulating material constituting the insulating material 114 is 10.0 μm or less, the material is easy to process, such as by grinding.

[0064] The method for measuring the average primary particle diameter of the insulating material that constitutes insulating material 114 is the same as the method for measuring the average primary particle diameter of the insulating material that constitutes mounting plate 111 and support plate 112.

[0065] [Power supply terminal] The power supply terminal 116 supplies a current to the electrostatic attraction electrode 113 . The number, shape, etc. of the power supply terminals 116 are determined by the type of the electrostatic attraction electrode 113, that is, whether it is a monopolar type or a bipolar type.

[0066] [Electrode pin] The electrode pin 118 supplies current to the power supply terminal 116. The electrode pin 118 has a structure similar to that of the electrode pin 30 shown in FIG. 1. The electrode pin 30 has a connection portion 31 that is pressed against the power supply terminal 5 to connect, and a spring 32 provided on the side of the connection portion 31 opposite to a tip portion 31A. The elastic force of the spring 32 presses the tip portion 31A against the power supply terminal 116, thereby connecting the power supply terminal 116 and the electrode pin 118.

[0067] [Temperature control base material] The temperature adjustment base member 103 is a thick, disk-shaped member made of at least one of metal and ceramic. The body of the temperature adjustment base member 103 also serves as an internal electrode for generating plasma. Inside the body of the temperature adjustment base member 103, a flow path 121 is formed for circulating a cooling medium such as water, He gas, or N2 gas.

[0068] The body of temperature adjusting base member 103 is connected to an external high-frequency power supply 122. Furthermore, electrode pin 118, the outer periphery of which is surrounded by insulating material 123, is fixed in fixing hole 117 of temperature adjusting base member 103 via insulating material 123. Electrode pin 118 is connected to an external DC power supply 124.

[0069] The material constituting the temperature adjusting base member 103 is not particularly limited as long as it is a metal with excellent thermal conductivity, electrical conductivity, and workability, or a composite material containing such a metal. Suitable materials for the temperature adjusting base member 3 include, for example, aluminum (Al), copper (Cu), stainless steel (SUS), and titanium (Ti). At least the surface of the temperature adjusting base member 103 that is exposed to plasma is preferably anodized or coated with a polyimide resin. It is more preferable that the entire surface of the temperature adjusting base member 103 is anodized or coated with the resin.

[0070] By applying anodizing or 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.

[0071] [Adhesive layer] The adhesive layer 104 bonds the electrostatic chuck portion 102 and the cooling base portion 103 together.

[0072] 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. If the thickness of the adhesive layer 104 is within the above range, it is possible to sufficiently maintain the adhesive strength between the electrostatic chuck portion 102 and the cooling base portion 103. In addition, it is possible to sufficiently ensure the thermal conductivity between the electrostatic chuck portion 102 and the cooling base portion 103.

[0073] The adhesive layer 104 is formed from, for example, a hardened product obtained by heat-hardening a silicone-based resin composition, an acrylic resin, an epoxy resin, or the like. A silicone-based resin composition is a silicon compound having a siloxane bond (Si—O—Si), and is a resin with excellent heat resistance and elasticity, and is therefore more preferred.

[0074] As such a silicone-based resin composition, a silicone resin having a heat curing temperature of 70°C to 140°C is particularly preferred. Here, if the thermosetting temperature is below 70°C, when the electrostatic chuck portion 102 and the cooling base portion 103 are bonded in a facing state, the hardening does not proceed sufficiently during the bonding process, which is undesirable because it results in poor workability. On the other hand, if the thermosetting temperature exceeds 140°C, the difference in thermal expansion between the electrostatic chuck portion 102 and the cooling base portion 103 becomes large, which increases the stress between the electrostatic chuck portion 102 and the cooling base portion 103 and may cause peeling between them, which is undesirable.

[0075] According to the electrostatic chuck device 100 of the present embodiment, the electrostatic chuck member 102 is made of the susceptor 1. Therefore, even if the electrode pin 118 is inclined with respect to the power supply terminal 116, a sufficient contact area can be secured between the inner surface of the recess including the power supply terminal 116 provided on the surface opposite to the mounting surface 111 a of the electrostatic chuck member 102 and the tip end of the electrode pin 118, and a change in this contact area can be suppressed.

[0076] A method for manufacturing the electrostatic chuck device of this embodiment will be described below.

[0077] An electrostatic chuck member 102 is prepared, which is made of the susceptor 1 obtained as described above.

[0078] 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. The amount of adhesive applied is adjusted so that the electrostatic chuck portion 102 and the cooling base portion 103 are bonded together. The adhesive can be applied manually using a spatula or the like, or by bar coating, screen printing, or the like.

[0079] After applying an adhesive to one main surface 103a of the cooling base portion 103, the electrostatic chuck portion 102 and the cooling base portion 103 to which the adhesive has been applied are superposed. Also, the electrode pins 118 are inserted into the fixing holes 117 drilled in the cooling base portion 103 and fitted therein. Next, the electrostatic chuck portion 102 is pressed against the cooling base portion 103 with a predetermined pressure to bond 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 bonded and integrated via the adhesive layer 104.

[0080] As a result of the above, the electrostatic chuck unit 102 and the cooling base unit 103 are integrally bonded together via the adhesive layer 104 to obtain the electrostatic chuck device 100 of this embodiment.

[0081] The plate-like sample according to this embodiment is not limited to a semiconductor wafer, but may be, for example, a glass substrate for a flat panel display (FPD) such as a liquid crystal display (LCD), a plasma display (PDP), or an organic electroluminescence (EL) display. The electrostatic chuck device according to this embodiment may be designed to match the shape and size of the substrate.

[0082] [Other embodiments] The present invention is not limited to the above-described embodiment.

[0083] For example, it is also possible to employ susceptors 200, 300, 400, and 500 according to first to fourth modified examples as shown in Figures 3 to 6. In the susceptors 200, 300, 400, and 500 according to the first to fifth modified examples, the same components as those in the above embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being described.

[0084] 3 has a recess 6 on the lower surface 2a of the first ceramic plate 2, which includes the power supply terminal 5 and the first ceramic plate 2 and is recessed toward the mounting surface 3a. That is, the inner surface 6a of the recess 6 is formed by a central portion 6A formed by the power supply terminal 5 and an outer edge portion 6B that follows the outer edge of the central portion 6A. This ensures a sufficient contact area between the inner surface 6a of the recess 6 and the tip end 31A of the electrode pin 30, and suppresses changes in this contact area, even if the inclination (deviation) of the electrode pin 30 with respect to the power supply terminal 5 increases.

[0085] 4 has a recess 6 on the lower surface 2a of the first ceramic plate 2, the recess 6 including the power supply terminal 5 and recessed toward the mounting surface 3a. In the susceptor 300 of this modification, the recess 6 is formed only in the power supply 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 power supply terminal 5. This reduces the inclination (deviation) of the electrode pin 30 with respect to the power supply terminal 5, ensures a sufficient contact area between the inner surface 6a of the recess 6 and the tip 31A of the electrode pin 30, and suppresses changes in this contact area.

[0086] 5, a susceptor 400 of a third modified example includes a power supply terminal 5 and the first ceramic plate 2 on the lower surface 2a of the first ceramic plate 2, and has a recess 6 recessed toward the mounting surface 3a. The susceptor 400 further includes a metal layer 410 covering the inner surface 6a of the recess 6. In the susceptor 400 of this modified example, 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. Furthermore, 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 or hyperbolic shape represented by at least one curvature or a quadratic function.

[0087] The metal layer 410 is made of a conductive material. The conductive material constituting the metal layer 410 is not particularly limited, but examples thereof include Ag, Cu, In, Ti, and Sn, and these may be used alone or in combination.

[0088] The arithmetic mean roughness (Ra) of the surface of metal layer 410 opposite to inner surface 6a of recess 6 (inner surface 411a of recess 411) is preferably 2 μm or more and 30 μm or less, more preferably 4 μm or more and 25 μm or less, and even more preferably 6 μm or more and 20 μm or less. If 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 of the power supply terminal 5 can be reduced.

[0089] The arithmetic mean roughness (Ra) of the inner surface 411a of the recess 411 is measured using a stylus-type surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd. in accordance with JIS B 0601:2013 "Geometric Product Specifications (GPS) - Surface Texture: Profile Curve Method - Terms, Definitions and Surface Texture Parameters."

[0090] By providing the metal layer 410, the resistance due to the connection between the power supply terminal 5 and the power supply pin 30 can be reduced, and the electrical connection between them can be improved.

[0091] A susceptor 500 of a fourth modification shown in FIG. 6 includes only a power supply terminal 5 on the lower surface 2a of the first ceramic plate 2, and has a recess 6 recessed toward the mounting surface 3a. Furthermore, the susceptor 400 includes a metal layer 510 covering the inner surface 6a of the recess 6. In this 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. Furthermore, 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 or hyperbolic shape represented by at least one curvature or a quadratic function. The metal layer 510 is made of a conductive material. Examples of conductive materials for the metal layer 510 include the same conductive materials as those for the metal layer 410. The provision of the metal layer 510 reduces the resistance due to the connection between the power supply terminal 5 and the power supply pin 30, thereby improving their electrical connection. [Industrial Applicability]

[0092] The susceptor of the present invention includes a power supply terminal on the surface opposite to the mounting surface and has a recess that is recessed toward the mounting surface. Therefore, even if a shear stress resulting from a difference in the linear expansion coefficients of the ceramic plate, the electrode, etc. is applied and the electrode pin is tilted relative to the power supply terminal, a change in the contact area between the power supply terminal and the electrode pin can be suppressed. Therefore, the susceptor is suitably used as an electrostatic chuck member of an electrostatic chuck device and is extremely useful. [Explanation of symbols]

[0093] 1 susceptor 2. Ceramic plate (first ceramic plate) 3. Ceramic plate (second ceramic plate) 4 electrodes 5 Power supply terminal 6 recess 30 electrode pins 100 Electrostatic chuck device 102 Electrostatic chuck member 103 Temperature control base member 104 Adhesive layer 111 Loading plate 112 Support plate 113 Electrostatic Adsorption Electrode 114 Insulation materials 115 Through hole 116 Power supply terminal 117 Fixed hole 118 Electrode Pin 121 Channel 122 High frequency power supply 123 Insulating Materials 124 DC power supply

Claims

1. An electrostatic chuck device comprising an electrostatic chuck member made of ceramic and a temperature adjusting base member made of metal bonded together via an adhesive layer, the electrostatic chuck member includes an electrode provided inside a ceramic plate having a mounting surface on which a sample is placed, and a power supply terminal provided to penetrate the ceramic plate so as to contact the electrode, a recessed portion recessed toward the placement surface on a surface opposite to the placement surface, the power supply terminal is exposed on the opposite surface and forms at least a part of the recess; the temperature adjusting base member has an electrode pin that is connected to the power supply terminal and supplies a current to the power supply terminal; The electrode pin has a connection portion that is pressed against the power supply terminal to be connected, and a spring that presses the connection portion against the power supply terminal, and the electrode pin is an electrostatic chuck device that can tilt with respect to the power supply terminal.

2. 2. The electrostatic chuck device according to claim 1, wherein a cross-sectional shape of the inner surface of the recess in the thickness direction of the ceramic plate is a curved or hyperbolic shape expressed by at least one curvature or a quadratic function.

3. The electrostatic chuck device of claim 2 , further comprising a metal layer coating the inner surface.

4. 4. The electrostatic chuck device 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.

5. 5. The electrostatic chuck device according to claim 1, wherein the electrode and the power supply terminal are made of a composite of an insulating material and a conductive material.

6. The insulating material includes aluminum oxide, aluminum nitride, silicon nitride, yttrium (III) oxide, yttrium aluminum garnet, and SmAlO ３ 6. The electrostatic chuck device according to claim 5, wherein the electrostatic chuck is at least one selected from the group consisting of:

7. The conductive material is Mo ２ 7. The electrostatic chuck device according to claim 5, wherein the material is at least one selected from the group consisting of C, Mo, WC, W, TaC, Ta, SiC, carbon black, carbon nanotubes, and carbon nanofibers.

Images