JP7673382B2 - Electrostatic chuck device and method for manufacturing electrostatic chuck device - Google Patents

Description

The present invention relates to an electrostatic chuck device and a method for manufacturing an electrostatic chuck device.

An electrostatic chuck device has an internal electrode for electrostatic attraction provided inside a dielectric material that serves as an electrostatic chuck member. In the electrostatic chuck device, a plate-shaped sample such as a semiconductor wafer is placed on the mounting surface of the electrostatic chuck member, and an electrostatic force is generated between the plate-shaped sample and the internal electrode for electrostatic attraction, thereby adsorbing and fixing the plate-shaped sample.

The electrostatic chuck member is joined and integrated with a temperature adjusting base member via an adhesive layer, and the temperature is kept constant by the temperature adjusting base member.
Conventionally, in order to keep the thickness of the adhesive layer constant, a spacer is provided within the adhesive layer (see, for example, Patent Documents 1 and 2).

JP 2016-058748 A JP 2017-059771 A

However, if a spacer having a different composition from that of the adhesive layer is provided within the adhesive layer, thermal stress during use can cause the spacer to peel off from the electrostatic chuck member or the temperature adjustment base member, which can lead to problems such as loss of temperature uniformity on the mounting surface of the electrostatic chuck member or generation of discharge when a voltage is applied to the electrostatic chuck member.

The present invention has been made in consideration of the above circumstances, and aims to provide an electrostatic chuck device and a method for manufacturing an electrostatic chuck device that ensures temperature uniformity on the mounting surface of an electrostatic chuck member for a long period of time and suppresses discharge when a voltage is applied to the electrostatic chuck member.

In order to solve the above problems, one aspect of the present invention provides an electrostatic chuck device comprising an electrostatic chuck member made of ceramics, a temperature adjustment base member made of metal, and an adhesive layer, characterized in that at the joining surface where the electrostatic chuck member and the temperature adjustment base member are joined, either the electrostatic chuck member or the temperature adjustment base member has a rough surface, and the electrostatic chuck member and the temperature adjustment base member are joined to the joining surface having the rough surface via the adhesive layer.

In one aspect of the present invention, the rough surface may be a protrusion.

In one aspect of the present invention, the height of the protrusions may be 25 μm or more and 400 μm or less.

In one aspect of the present invention, the rough surface may have an arithmetic mean roughness (Ra) of the joining surface of 0.01 μm or more and 2.0 μm or less.

One aspect of the present invention provides a method for manufacturing an electrostatic chuck device in which an electrostatic chuck member made of ceramics and a temperature adjustment base member made of metal are bonded via an adhesive layer, the method including the steps of: roughening one of the bonding surfaces of the electrostatic chuck member that is bonded to the temperature adjustment base member to form a convex portion; and bonding the roughened bonding surface to the electrostatic chuck member and the temperature adjustment base member via an adhesive.

The present invention provides an electrostatic chuck device and electrostatic chuck apparatus that ensures temperature uniformity of the mounting surface of the electrostatic chuck member for a long period of time and suppresses discharge when a voltage is applied to the electrostatic chuck member.

1 is a cross-sectional view of an electrostatic chuck device according to an embodiment of the present invention.

Below, an embodiment of an electrostatic chuck device and a method for manufacturing 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 enlarged views of characteristic parts for the sake of convenience, and the dimensional ratios of each component may differ from the actual ones. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited to them, and may be modified as appropriate within the scope of the present invention.

[Electrostatic chuck device]
An electrostatic chuck device according to one embodiment of the present invention is an electrostatic chuck device comprising an electrostatic chuck member made of ceramics, a temperature adjustment base member made of metal, and an adhesive layer, wherein at a joining surface where the electrostatic chuck member and the temperature adjustment base member are joined, either the electrostatic chuck member or the temperature adjustment base member has a rough surface, and the electrostatic chuck member and the temperature adjustment base member are joined via the adhesive layer.

"Electrostatic chuck device"
First, an electrostatic chuck device according to the present embodiment will be described with reference to FIG.
FIG. 1 is a cross-sectional view showing an electrostatic chuck device according to the present embodiment.
As shown in FIG. 1 , an electrostatic chuck device 1 of the present embodiment includes a disk-shaped electrostatic chuck member 2, a disk-shaped temperature adjustment base member 3 that adjusts the electrostatic chuck member 2 to a desired temperature, and an adhesive layer 4 that bonds and integrates the electrostatic chuck member 2 and the temperature adjustment base member 3.
In the following description, the side of the mounting surface 11a of the mounting plate 11 will be referred to as "upper" and the side of the temperature adjusting base member 3 as "lower" to indicate the relative positions of each component.

"Electrostatic chuck components"
The electrostatic chuck member 2 includes a mounting plate 11 made of ceramics having an upper surface serving as a mounting surface 11a on which a plate-like sample such as a semiconductor wafer is placed, a support plate 12 provided on the side of the mounting plate 11 opposite the mounting surface 11a, an electrostatic attraction electrode 13 held between the mounting plate 11 and the support plate 12, a ring-shaped insulating material 14 held between the mounting plate 11 and the support plate 12 and surrounding the electrostatic attraction electrode 13, a power supply terminal 16 provided in a through hole 15 of the support plate 12 so as to be in contact with the electrostatic attraction electrode 13, and an electrode pin 18 provided in a fixing hole 17 of the temperature control base member 3.

"Placement plate"
A number of protrusions (not shown) are provided on the mounting surface 11a of the mounting plate 11 to support a plate-shaped sample such as a semiconductor wafer. Furthermore, a circular protrusion having a square cross section may be provided around the periphery of the mounting surface 11a of the mounting plate 11 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 circular cross section, and a substantially rectangular vertical section may be provided in the area surrounded by the circular protrusion on the mounting surface 11a.

The material of the mounting plate 11 is not particularly limited as long as it has a volume resistivity of about 10 ¹³ Ω·cm or more and 10 ¹⁵ Ω·cm or less, mechanical strength, and durability against corrosive gas and its plasma. Examples of such materials include aluminum oxide (Al ₂ O ₃ ) sintered body, aluminum nitride (AlN) sintered body, aluminum oxide (Al ₂ O ₃ )-silicon carbide (SiC) composite sintered body, etc., but aluminum oxide (Al ₂ O ₃ )-silicon carbide (SiC) composite sintered body is preferable from the viewpoints of dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance.

"Support plate"
The support plate 12 supports the mounting plate 11 and the electrostatic attraction electrode 13 from below.

The material of the support plate 12 is the same as the material of the mounting plate 11.

The support plate 12 has a rough surface (joint surface) 12a which is joined to the temperature adjusting base member 3. Specifically, the rough surface of the support plate 12, which is joined to the temperature adjusting base member 3 (joint surface) 12a, is preferably provided with protrusions 19.
The protrusions 19 are provided to make the thickness of the adhesive layer 4 uniform.

The shape of the protrusion 19 is not particularly limited, and examples of the shape when viewed from the joining surface 12a side include a triangular shape, a rectangular shape, a polygonal shape with pentagons or more sides, a circular shape, an elliptical shape, etc.

The height of the protrusions 19 based on the joining surface 12a is preferably 25 μm or more and 400 μm or less, and more preferably 50 μm or more and 350 μm or less. If the height of the protrusions 19 is 25 μm or more, the thickness of the adhesive layer 4 can be made uniform. On the other hand, if the height of the protrusions 19 is 400 μm or less, stress relaxation due to heat can be absorbed, a decrease in the withstand voltage can be prevented, and there is no effect on heat transfer. If the height of the protrusions 19 based on the joining surface 12a is within the above range, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (the mounting surface 11a of the mounting plate 11) can be ensured. In addition, the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2 can be suppressed.

The height of the protrusions 19 is measured using a surface roughness and contour shape composite measuring device (product name: SURFCOM NEX, manufactured by Tokyo Seimitsu Co., Ltd.).

The arithmetic mean roughness (Ra) of the joining surface 12a is preferably 0.01 μm or more and 2.0 μm or less, and more preferably 0.1 μm or more and 1.5 μm or less. If the arithmetic mean roughness (Ra) of the joining surface 12a is equal to or more than the lower limit, the thickness of the adhesive layer 4 can be made uniform. If the arithmetic mean roughness (Ra) of the joining surface 12a is equal to or less than the upper limit, the adhesiveness is improved by the anchor effect, and air bubbles do not remain between the adhesive layer 4 and the joining surface, which is preferable. If the arithmetic mean roughness (Ra) of the joining surface 12a is within the above range, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (the mounting surface 11a of the mounting plate 11) can be ensured. In addition, the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2 can be suppressed.

The arithmetic mean roughness (Ra) of the joining surface 12a is measured using a Tokyo Seimitsu stylus-type surface roughness tester in accordance with JIS B 0601:2013 "Geometric product specifications (GPS) - Surface quality: profile curve method - Terms, definitions and surface quality parameters."

The outer diameter of the protrusion 19 as viewed from the joining surface 12a side is preferably 0.05 mm or more and 3.0 mm or less, and more preferably 0.1 mm or more and 2.0 mm or less. If the outer diameter of the protrusion 19 is equal to or more than the lower limit, the thickness of the adhesive layer 4 can be made uniform. If the outer diameter of the protrusion 19 is equal to or less than the upper limit, the protrusion 19 does not bite into the joining surface and does not deform, and sufficient adhesive strength can be obtained. If the outer diameter of the protrusion 19 as viewed from the joining surface 12a side is within the above range, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (the mounting surface 11a of the mounting plate 11) can be ensured. In addition, it is possible to suppress the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2.
In addition, the outer diameter of protrusion 19 is the diameter of the circle if the shape of protrusion 19 when viewed from the joining surface 12a side is circular; the outer diameter of protrusion 19 is the major axis of the ellipse if the shape of protrusion 19 when viewed from the joining surface 12a side is elliptical; the outer diameter of protrusion 19 is the longest side of the triangle if the shape of protrusion 19 when viewed from the joining surface 12a side is triangular; and the outer diameter of protrusion 19 is the longest diagonal if the shape of protrusion 19 when viewed from the joining surface 12a side is rectangular or polygonal.

The ratio (occupancy rate) of the projections 19 on the joining surface 12a is preferably 0.01% to 5.0% and more preferably 0.5% to 3.5% of the total area of the joining surface 12a. If the occupancy rate of the projections 19 is equal to or greater than the lower limit, the thickness of the adhesive layer 4 can be made uniform. If the occupancy rate of the projections 19 is equal to or less than the upper limit, the thickness of the adhesive layer does not vary and the adhesive strength can be ensured. If the ratio (occupancy rate) of the projections 19 on the joining surface 12a is within the above range, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (mounting surface 11a of the mounting plate 11) can be ensured. In addition, the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2 can be suppressed.

"Electrostatic adhesion electrode"
When a voltage is applied to the electrostatic attraction electrode 13 , an electrostatic attraction force is generated to hold the plate-shaped sample on the mounting surface 11 a of the mounting plate 11 .

The electrostatic adsorption electrode 13 is a composite of an insulating material and a conductive material.

The insulating material contained in the electrostatic attraction electrode 13 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 conductive material contained in the electrostatic attraction electrode 13 is preferably at least one selected from the group consisting of molybdenum carbide ( _Mo2C ), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC), carbon black, carbon nanotubes, and carbon nanofibers.

"Insulation material"
The insulating material 14 surrounds the electrostatic attraction electrode 13 to protect the electrostatic attraction electrode 13 from corrosive gases and their plasma.
The mounting plate 11 and the support plate 12 are joined together via the electrostatic attraction electrode 13 by an insulating material 14 .

The insulating material 14 is provided to join the boundary between the mounting plate 11 and the support plate 12, i.e., the outer edge region other than the portion forming the electrostatic attraction electrode 13. The shape of the insulating material 14 (the shape of the insulating material 14 when viewed in a plan view (viewed from the thickness direction)) is not particularly limited and is adjusted as appropriate depending on the shape of the electrostatic attraction electrode 13.
In the electrostatic chuck device 1 of the present embodiment, the thickness of the insulating material 14 is equal to the thickness of the electrostatic attraction electrode 13 .

The insulating material 14 is made of an insulating material.
The insulating material constituting the insulating material 14 is not particularly limited, but is preferably the same as the main component of the mounting plate 11 and the support plate 12, and examples thereof include aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), yttrium oxide (Y ₂ O ₃ ), yttrium aluminum garnet (YAG), etc. The insulating material constituting the insulating material 14 is preferably aluminum oxide (Al ₂ O ₃ ). By using aluminum oxide (Al ₂ O ₃ ) as the insulating material constituting the insulating material 14, the dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance are maintained.

"Power supply terminal"
The power supply terminal 16 supplies a current to the electrostatic attraction electrode 13 .
The number, shape, etc. of the power supply terminals 16 are determined depending on the type of the electrostatic attraction electrode 13, that is, whether it is a monopolar type or a bipolar type.

"Electrode pin"
The electrode pin 18 supplies a current to the power supply terminal 16 .

"Temperature adjustment base material"
The temperature adjustment base member 3 is a thick disk-shaped member made of at least one of metal and ceramics. The body of the temperature adjustment base member 3 also serves as an internal electrode for generating plasma. Inside the body of the temperature adjustment base member 3, a flow path 21 is formed for circulating a cooling medium such as water, He gas, or _N2 gas.

The body of the temperature adjustment base member 3 is connected to an external high-frequency power source 22. In addition, an electrode pin 18, the outer periphery of which is surrounded by an insulating material 23, is fixed in the fixing hole 17 of the temperature adjustment base member 3 via the insulating material 23. The electrode pin 18 is connected to an external DC power source 24.

The material constituting the temperature adjusting base member 3 is not particularly limited as long as it is a metal having 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 3 that is exposed to plasma is preferably anodized or resin-coated with polyimide resin. More preferably, the entire surface of the temperature adjusting base member 3 is anodized or resin-coated.

By applying anodizing or resin coating to the temperature adjustment base member 3, the plasma resistance of the temperature adjustment base member 3 is improved and abnormal discharge is prevented. Therefore, the plasma resistance stability of the temperature adjustment base member 3 is improved and the occurrence of surface scratches on the temperature adjustment base member 3 can be prevented.

"Adhesive layer"
The adhesive layer 4 bonds and integrates the electrostatic chuck member 2 and the temperature adjusting base member 3 together.

The adhesive layer 4 is formed of, for example, a hardened product obtained by heating and hardening a silicone-based resin composition, an acrylic resin, an epoxy resin, a polyimide resin, or the like.
A silicone-based resin composition is a silicon compound having a siloxane bond (Si--O--Si), and is a resin having excellent heat resistance and elasticity, and is therefore more preferred.

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 heat curing temperature is below 70° C., when the electrostatic chuck member 2 and the temperature adjustment base member 3 are joined in a facing state, the curing does not proceed sufficiently during the joining process, which is undesirable because workability is deteriorated. On the other hand, if the heat curing temperature exceeds 140° C., the thermal expansion difference between the electrostatic chuck member 2 and the temperature adjustment base member 3 becomes large, which increases the stress between the electrostatic chuck member 2 and the temperature adjustment base member 3, which is undesirable because peeling may occur between them.

According to the electrostatic chuck device 1 of this embodiment, the support plate 12 constituting the electrostatic chuck member 2 has protrusions 19 on the surface (bonding surface) 12a that bonds with the temperature adjustment base member 3, so that the thickness of the adhesive layer 4 that bonds the electrostatic chuck member 2 and the temperature adjustment base member 3 can be made uniform. In addition, peeling of the adhesive surface that occurs when a spacer is used can be reduced. As a result, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (mounting surface 11a of the mounting plate 11) can be ensured, and discharge can be suppressed when a voltage is applied to the electrostatic chuck member 2.

In the present embodiment, the surface (joint surface) 12a of the support plate 12 constituting the electrostatic chuck member 2 that is joined to the temperature adjustment base member 3 has the protrusions 19, but the present invention is not limited to this. In the present invention, the surface (joint surface) of the temperature adjustment base member that is joined to the electrostatic chuck member may have protrusions similar to the protrusions 19 described above.

"Method of manufacturing electrostatic chuck device"
The electrostatic chuck member 2 as described above is prepared.
A surface (joint surface) 2a of the electrostatic chuck member 2 which is joined to the temperature adjustment base member 3 is roughened. In other words, the joint surface 12a of the support plate 12 which constitutes the electrostatic chuck member 2 is roughened.

The method for roughening the joining surface 12a is not particularly limited, but examples include sandblasting, reciprocating machining, and numerical control (NC) machining.

In the process of roughening the joining surface 12a, as described above, it is preferable to form protrusions (convex portions) 19 on the joining surface 12a. By forming the protrusions 19 on the joining surface 12a, the thickness of the adhesive layer 4 can be made uniform.

In the process of roughening the joining surface 12a, as described above, the height of the protrusions is preferably 25 μm or more and 400 μm or less, and more preferably 50 μm or more and 350 μm or less. If the height of the protrusions 19 is equal to or more than the lower limit, the thickness of the adhesive layer 4 can be made uniform. On the other hand, if the height of the protrusions 19 is equal to or less than the upper limit, the stress relaxation due to heat is absorbed, the decrease in the withstand voltage is prevented, and there is no effect on the transfer of heat. If the height of the protrusions 19 based on the joining surface 12a is within the above range, the uniformity of the temperature of the mounting surface of the electrostatic chuck member 2 (the mounting surface 11a of the mounting plate 11) can be ensured. In addition, the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2 can be suppressed.

In the step of roughening the joining surface 12a, as described above, the arithmetic mean roughness (Ra) of the joining surface 12a is preferably 0.01 μm or more and 2.0 μm or less, and more preferably 0.1 μm or more and 1.5 μm or less. If the arithmetic mean roughness (Ra) of the joining surface 12a is equal to or more than the lower limit, the thickness of the adhesive layer 4 can be made uniform. If the arithmetic mean roughness (Ra) of the joining surface 12a is equal to or less than the upper limit, the adhesiveness is improved by the anchor effect, and air bubbles do not remain between the adhesive layer 4 and the joining surface, which is preferable. If the arithmetic mean roughness (Ra) of the joining surface 12a is within the above range, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (the mounting surface 11a of the mounting plate 11) can be ensured. In addition, the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2 can be suppressed.

In addition, in the process of roughening the joining surface 12a, the outer diameter of the protrusion 19 as viewed from the joining surface 12a side is preferably 0.05 mm or more and 3.0 mm or less, and more preferably 0.1 mm or more and 2.0 mm or less. If the outer diameter of the protrusion 19 is equal to or more than the lower limit, the thickness of the adhesive layer 4 can be made uniform. If the outer diameter of the protrusion 19 is equal to or less than the upper limit, the protrusion 19 does not bite into the joining surface and does not deform, and sufficient adhesive strength can be obtained. If the outer diameter of the protrusion 19 as viewed from the joining surface 12a side is within the above range, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (the mounting surface 11a of the mounting plate 11) can be ensured. In addition, the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2 can be suppressed.

Furthermore, in the process of roughening the joining surface 12a, the ratio (occupancy rate) of the protrusions 19 on the joining surface 12a is preferably 0.01% to 5.0% and more preferably 0.5% to 3.5% of the total area of the joining surface 12a. If the occupancy rate of the protrusions 19 is equal to or greater than the lower limit, the thickness of the adhesive layer 4 can be made uniform. If the occupancy rate of the protrusions 19 is equal to or less than the upper limit, the thickness of the adhesive layer does not vary and the adhesive strength can be ensured. If the ratio (occupancy rate) of the joining surface 12a that the protrusions 19 occupy is within the above range, the temperature uniformity of the mounting surface of the electrostatic chuck member 2 (mounting surface 11a of the mounting plate 11) can be ensured. In addition, it is possible to suppress the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2.

An adhesive made of a silicone-based resin composition is applied to a predetermined region of one main surface (upper surface) 3a of the temperature adjustment base member 3. The amount of adhesive applied is adjusted so that the electrostatic chuck member 2 and the temperature adjustment base member 3 can be bonded and integrated together.
The adhesive can be applied manually using a spatula or the like, or by a bar coating method, a screen printing method, or the like.

The joining surface 2a roughened as described above is joined to the temperature adjusting base member 3 via an adhesive.
More specifically, after applying adhesive to one main surface (upper surface) 3a of the temperature adjustment base member 3, the electrostatic chuck member 2 and the temperature adjustment base member 3 to which the adhesive has been applied are overlapped with each other with the joining surface 2a facing toward the temperature adjustment base member 3.

Moreover, the electrode pin 18 is inserted and fitted into the fixing hole 17 drilled in the temperature adjusting base member 3 .
Next, the electrostatic chuck member 2 is pressed against the temperature adjustment base member 3 with a predetermined pressure to bond and integrate the electrostatic chuck member 2 and the temperature adjustment base member 3. As a result, the electrostatic chuck member 2 and the temperature adjustment base member 3 are bonded and integrated via the adhesive layer 4.

As a result of the above, an electrostatic chuck device 1 is obtained in which the electrostatic chuck member 2 and the temperature adjustment base member 3 are bonded together via the adhesive layer 4.

According to the manufacturing method of the electrostatic chuck device of this embodiment, the thickness of the adhesive layer 4 that bonds the electrostatic chuck member 2 and the temperature adjustment base member 3 can be made uniform by roughening the bonding surface 12a. As a result, an electrostatic chuck device is obtained that ensures uniformity in temperature of the mounting surface (mounting surface 11a of the mounting plate 11) of the electrostatic chuck member 2 and can suppress the occurrence of discharge when a voltage is applied to the electrostatic chuck member 2.

In the present embodiment, the protrusions 19 are formed on the surface (joint surface) 12a of the support plate 12 constituting the electrostatic chuck member 2 that is joined to the temperature adjustment base member 3, but the present invention is not limited to this. In the present invention, protrusions similar to the protrusions 19 may be formed on the surface (joint surface) of the temperature adjustment base member that is joined to the electrostatic chuck member.

The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

"Example 1"
(Preparation of electrostatic chuck device)
An electrostatic chuck portion 2 having an electrostatic attraction internal electrode 13 with a thickness of 20 μm embedded therein was fabricated by a known method.
The mounting plate 11 of the electrostatic chuck portion 2 was an aluminum oxide-silicon carbide composite sintered body containing 8.5 mass % silicon carbide, and was disk-shaped with a diameter of 298 mm and a thickness of 0.5 mm. The electrostatic attraction surface of the mounting plate 11 was made uneven by forming a large number of protrusions 16 with a height of 40 μm, and the top surfaces of these protrusions 16 served as the holding surface for the plate-shaped sample W, allowing a cooling gas to flow through the grooves formed between the recesses and the electrostatically attracted plate-shaped sample W.

Similarly to the mounting plate 11, the support plate 12 was an aluminum oxide-silicon carbide composite sintered body containing 8.5 mass % of silicon carbide, and was in the shape of a disk having a diameter of 298 mm and a thickness of 2 mm.
By joining the mounting plate 11 and the support plate 12 together, the overall thickness of the electrostatic chuck portion 2 was 2.5 mm.

On the other hand, a temperature adjustment base part 3 made of aluminum with a diameter of 350 mm and a height of 30 mm was produced by machining. Inside this temperature adjustment base part 3, a flow path (not shown) for circulating the refrigerant was formed.

Next, cylindrical protrusions with a diameter of 0.5 mm and a height of 100 μm were created on the back side of the mounting surface of the electrostatic chuck by sandblasting. The proportion (occupancy rate) of the protrusions was set to 1.0% of the total area of the bonding surface (100%) (3,598 protrusions were created for a mounting plate with a diameter of 298 mm), and they were formed so as to be uniformly distributed on the back side of the mounting surface.

Next, a silicone-based resin composition was applied onto the temperature adjusting base part by a screen printing method, and then the electrostatic chuck part and the temperature adjusting base part were laminated together with the silicone-based resin composition interposed therebetween.
Next, the electrostatic chuck portion and the temperature adjusting base portion were lowered until the gap between them became 100 μm, and then the substrate was held at 110° C. for 12 hours to harden the silicone-based resin composition and bond the electrostatic chuck portion and the temperature adjusting base portion together, thereby producing the electrostatic chuck device of Example 1.

"Surface roughness of the joint surface (Ra)
Before applying the silicone resin composition, the surface roughness and contour shape were measured using a composite measuring instrument (product name: SURFCOM NEX, manufactured by Tokyo Seimitsu Co., Ltd.). The results are shown in Table 1.

"Example 2"
Except for providing the protrusions on the temperature adjusting base member, an electrostatic chuck device of Example 2 was produced in the same manner as in Example 1. The results are shown in Table 1.

"Comparative Example 1"
In Example 1, no protrusions were provided on the electrostatic chuck mounting plate, and polyimide spacers with a width of 2 mm, length of 2 mm, and height of 100 μm were used. The electrostatic chuck device of Comparative Example 1 was produced in the same manner as in Example 1, except that the amount of spacers added was adjusted to 0.48% (85 polyimide spacers were used in the case of a mounting plate with a diameter of 298 mm) relative to 100% of the total area of the bonding surface. The surface roughness of the polyimide spacers was 0.03 to 0.07 μm. The results are shown in Table 1.

"Implementation Test"
The electrostatic chuck device was installed in a plasma processing device, and a 3000-hour mounting test was performed. The temperature of the mounting surface was measured using a thermograph TVS-200EX (manufactured by Nippon Avionics Co., Ltd.) immediately after the start of the mounting test and immediately before the end of the test. The results are shown in Table 1.

According to the above results, in Examples 1 and 2, the difference in the variation in the surface temperature of the mounting surface before and after the mounting test is small compared to Comparative Example 1, and there is almost no change.
This is believed to have occurred because, when a spacer was used, during a long-term mounting test, the adhesive layer present on the back surface of the spacer and the mounting surface of the electrostatic chuck or at the interface with the temperature adjustment base member gradually peeled off due to repeated expansion and contraction due to thermal history, resulting in a partial change in the thermal conductivity coefficient.
For the above reasons, the present invention is useful.

REFERENCE SIGNS LIST 1 Electrostatic chuck device 2 Electrostatic chuck member 3 Temperature adjustment base member 4 Adhesive layer 11 Placement plate 12 Support plate 13 Electrostatic attraction electrode 14 Insulating material 15 Through hole 16 Power supply terminal 17 Fixing hole 18 Electrode pin 19 Protrusion 21 Flow path 22 High frequency power source 23 Insulating material 24 DC power source

Claims (5)

An electrostatic chuck device comprising: an electrostatic chuck member made of ceramics; a temperature adjustment base member made of metal; and an adhesive layer,
a joint surface between the electrostatic chuck member and the temperature adjustment base member, the joint surface being roughened on either the electrostatic chuck member or the temperature adjustment base member;
the electrostatic chuck member and the temperature adjustment base member are joined via the adhesive layer,
The rough surface is composed of a plurality of protrusions,
the plurality of protrusions have the same height and are in contact with either the electrostatic chuck member or the temperature adjustment base member,
an area ratio of the plurality of protrusions to the joining surface is 0.01% or more and 1.0 % or less with respect to 100% of a total area of the joining surface; The electrostatic chuck device according to claim 1, wherein the outer diameter of the protrusion when viewed from the joining surface side is 0.05 mm or more and 3.0 mm or less. The electrostatic chuck device according to claim 2, wherein the height of the protrusions is 25 μm or more and 400 μm or less. The electrostatic chuck device according to any one of claims 1 to 3, wherein the rough surface has an arithmetic mean roughness (Ra) of the joining surface of 0.01 μm or more and 2.0 μm or less. A method for manufacturing an electrostatic chuck device in which an electrostatic chuck member made of ceramics and a temperature adjustment base member made of metal are bonded together via an adhesive layer, the method comprising the steps of:
a step of performing a surface roughening process to form a plurality of protrusions on one of the electrostatic chuck member and the temperature adjustment base member at a joining surface between the electrostatic chuck member and the temperature adjustment base member;
and bonding the roughened bonding surface to the electrostatic chuck member and the temperature adjustment base member via an adhesive.
In the step of roughening the surface, the height of the plurality of protrusions is made uniform, and the ratio of the area of the bonding surface occupied by the plurality of protrusions is set to 0.01% or more and 1.0 % or less with respect to 100% of the total area of the bonding surface;
In the joining step, the plurality of protrusions are brought into contact with the other of the electrostatic chuck member and the temperature adjustment base member to join them.

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