JP5343802B2 - Electrostatic chuck device - Google Patents

Description

  The present invention relates to an electrostatic chuck device, and more particularly to an electrostatic chuck device suitable for use in performing a process such as plasma etching on a semiconductor substrate such as a silicon wafer.

  In recent years, in the semiconductor industry that supports IT technology, which is rapidly progressing, higher integration and higher performance of elements are required. For this reason, further improvement in microfabrication technology is also required in the semiconductor manufacturing process. . In this semiconductor manufacturing process, the etching technique is an important one of the microfabrication techniques. In recent years, the plasma etching technique capable of high-efficiency and large-area microfabrication has become the mainstream among the etching techniques. .

  For example, in an LSI manufacturing process using a silicon wafer, a mask pattern is formed on the silicon wafer with a resist, and a reactive gas is introduced into the vacuum while the silicon wafer is supported in a vacuum. By applying a high-frequency electric field to this reactive gas, accelerated electrons collide with gas molecules to form a plasma state, and the radicals (free radicals) and ions generated from this plasma react with the silicon wafer to produce a reaction. This is a technique for forming a fine pattern on a silicon wafer by removing it as an object.

2. Description of the Related Art Conventionally, in a semiconductor manufacturing apparatus such as a plasma etching apparatus, an electrostatic chuck apparatus is used as an apparatus for simply mounting and fixing a silicon wafer on a sample stage and maintaining the silicon wafer at a desired temperature. .
As such an electrostatic chuck device, for example, an organic film such as polyimide is used as a dielectric layer for fixing a silicon wafer, and the organic film is bonded to two ceramic plates through an insulating adhesive. There has been proposed an electrostatic chuck device having a structure in which it is sandwiched and bonded (Patent Document 1).

  There has also been proposed an electrostatic chuck device in which an upper surface of a ceramic substrate is a mounting surface on which a silicon wafer is mounted, and an electrostatic chucking electrode made of a refractory metal is embedded therein (Patent Document 2). There has also been proposed an electrostatic chuck device in which a ceramic sprayed film is formed on the surface of a ceramic substrate on which a silicon wafer is placed.

Japanese Patent Publication No. 5-87177 JP-A-9-283606

By the way, various conventional electrostatic chuck devices have the following various problems.
(1) In an apparatus using an organic film such as polyimide for the dielectric layer, although an organic film such as polyimide is inexpensive, it is weak in resistance to oxygen plasma and corrosive gas, and is an organic film. Therefore, the mechanical strength is weak, and there is a risk of damage due to electric discharge during use. The frequency of this breakage is high, and particles are generated at the time of breakage, resulting in a problem that productivity is lowered.
In addition, in the structure in which two ceramic plates are bonded via an organic adhesive, there is a problem in that the temperature variation in the wafer surface due to the variation in the thickness of each adhesive layer increases due to having two adhesive layers. May occur.

(2) An apparatus in which an insulating ceramic is sprayed on the surface of a metal substrate such as aluminum, and an electrode (metal) sprayed film and a ceramic sprayed film are formed on the upper surface thereof, compared with an apparatus using an organic film such as polyimide. Although it has excellent resistance to oxygen-based plasma and mechanical strength, particles may be generated when fine processing is performed on a silicon wafer due to peeling of the ceramic sprayed film. It becomes a factor to reduce.
(3) In the device in which the electrode for electrostatic adsorption is embedded in the ceramic substrate, compared with the device using organic film such as polyimide or ceramic sprayed film, in terms of plasma corrosion resistance, mechanical strength, and particles Although it is excellent, it has problems such as difficulty in manufacturing and high manufacturing cost.

  The present invention has been made to solve the above-described problems, and has high resistance to oxygen plasma and corrosive gas and high insulation resistance, low frequency of damage due to discharge during use, and generation of particles. It is an object of the present invention to provide an electrostatic chuck apparatus that is small in quantity and has a small temperature variation in the wafer surface and is inexpensive.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have used the electrostatic adsorption electrode provided on the ceramic plate-like body as the sheet-like or film-like first organic adhesive layer. Covered with a sheet-like or film-like insulating layer, and the base is bonded to the insulating layer via a second organic adhesive layer, and the outer peripheral portion of the insulating layer is made of a ceramic plate-like body It is found that the above problem can be easily solved if the outer periphery of the insulating layer is covered with the second organic adhesive layer while the inner periphery of the insulating layer is covered , and the present invention is completed. It reached.

That is, in the electrostatic chuck device of the present invention, an electrostatic chuck part including one main surface of the ceramic plate-like body as a mounting surface on which a wafer is mounted and an electrostatic chucking electrode on the other main surface; An electrostatic chuck device comprising: a base provided on the other main surface side and supporting the ceramic plate-like body;
The electrode for electrostatic attraction is covered with a sheet-like or film-like insulating layer via a sheet-like or film-like first organic adhesive layer, and a second organic-based adhesive is attached to this insulating layer. The base is bonded through the agent layer ,
The outer peripheral part of the insulating layer is inside the outer peripheral part of the ceramic plate-like body, and the outer peripheral part of the insulating layer is covered with the second organic adhesive layer .

In this electrostatic chuck device, an electrostatic adsorption electrode provided on a ceramic plate is covered with a sheet-like or film-like insulating layer via a sheet-like or film-like first organic adhesive layer. Thus, the electrostatic adsorption electrode is protected by the two-layer structure of the first organic adhesive layer and the sheet-like or film-like insulating layer, and the electrostatic adsorption electrode is resistant to oxygen-based plasma and corrosive gas. is increased, resistance to dielectric edge of the sheet-shaped or film-shaped insulating layer also Ri heightened, withstand voltage of the electrostatic attraction electrodes is improved.

In addition, since the base is bonded to the sheet-like or film-like insulating layer via the second organic adhesive layer, it appears on the sheet-like or film-like insulating layer due to the planar shape of the electrostatic adsorption electrode. The unevenness is flattened by the second organic adhesive layer, resistance to oxygen-based plasma and corrosive gas and insulation resistance are increased, the frequency of breakage due to discharge during use is low, and the amount of particles generated is small .
Furthermore, the outer peripheral portion of the sheet-like or film-like insulating layer is set inside the outer peripheral portion of the ceramic plate-like body, and the outer peripheral portion of the insulating layer is covered with the second organic adhesive layer. The sheet-like or film-like insulating layer is covered with the second organic adhesive layer to be protected from the outside, and the resistance of the sheet-like or film-like insulating layer to oxygen-based plasma is improved. There is no risk of corrosion by plasma.
Due to the above, electrostatic chucks with high resistance to oxygen-based plasma and corrosive gas, high mechanical strength, high mechanical strength, low frequency of breakage due to discharge during use, low particle generation, and low cost An apparatus can be provided.

The first organic adhesive layer is a sheet-like or film-like organic adhesive layer attached by thermocompression bonding.
In this electrostatic chuck device, the first organic adhesive layer is made of a sheet-like or film-like organic adhesive layer adhered by thermocompression bonding. The thickness becomes uniform, and the thermal conductivity between the ceramic plate and the base becomes uniform. Thereby, the cooling characteristics of the mounted wafer are made uniform, and the in-plane temperature of the wafer is made uniform.

The thermal conductivity of the second organic adhesive layer is 0.25 W / mk or more, the thermal conductivity of the first organic adhesive layer, and the thermal conductivity of the sheet-like or film-like insulating layer. Is equal to or less than the thermal conductivity of the second organic adhesive layer.
In this electrostatic chuck device, the temperature rise of the second organic adhesive layer is suppressed, and corrosion due to oxygen-based plasma or corrosive gas is prevented.
Also, by making the thermal conductivity of the first organic adhesive layer and the thermal conductivity of the sheet-like or film-like insulating layer equal to or lower than the thermal conductivity of the second organic adhesive layer The influence of heat transfer due to the variation in the thickness of the second organic adhesive layer is reduced, the non-uniformity of the temperature of the wafer to be placed is suppressed, and the in-plane temperature of the wafer is made uniform.

According to the electrostatic chuck device of the present invention, the electrostatic chucking electrode is covered with a sheet-like or film-like insulating layer via a sheet-like or film-like first organic adhesive layer, and the insulating layer is covered with this insulating layer. Since the base is bonded via the second organic adhesive layer, the electrostatic adsorption electrode is double protected by the first organic adhesive layer and the sheet-like or film-like insulating layer, Therefore, the insulation resistance of the base and the side surface can be improved, and the withstand voltage of the electrostatic chucking electrode can be improved. Therefore, the frequency of breakage due to discharge or the like during use is low, and the amount of particles generated at the time of breakage is small.

In addition, since the base is bonded to the sheet-like or film-like insulating layer via the second organic adhesive layer, the surface of the sheet-like or film-like insulating layer is affected by the planar shape of the electrode for electrostatic adsorption. Can be flattened by the second organic adhesive layer.
Furthermore, since the outer peripheral portion of the sheet-like or film-like insulating layer is located inside the outer peripheral portion of the ceramic plate-like body, and the outer peripheral portion of this insulating layer is covered with the second organic adhesive layer, this sheet-like or The film-like insulating layer can be protected from the outside by covering it with the second organic adhesive layer, and the resistance of the sheet-like or film-like insulating layer to oxygen-based plasma can be improved. There is no risk of corrosion.
As described above, it is possible to provide an electrostatic chuck device that has high resistance to oxygen-based plasma and corrosive gas, high insulation resistance, low frequency of breakage due to discharge during use, low particle generation, and low cost. it can.

  In addition, since the first organic adhesive layer is a sheet-like or film-like organic adhesive layer adhered by thermocompression bonding, the thickness of the first organic adhesive layer is made uniform. And the thermal conductivity between the ceramic plate and the base can be made uniform. Therefore, the cooling characteristics of the mounted wafer can be made uniform, and the in-plane temperature of the wafer can be made uniform.

Further, the thermal conductivity of the second organic adhesive layer is 0.25 W / mk or more, and the thermal conductivity of the first organic adhesive layer and the thermal conductivity of the sheet-like or film-like insulating layer are: Since the thermal conductivity of the second organic adhesive layer is equal to or lower than that of the second organic adhesive layer, the temperature rise of the second organic adhesive layer can be suppressed and corrosion due to oxygen-based plasma or corrosive gas is prevented. can do.
Further, the temperature of the wafer to be placed can be made uniform, and the in-plane temperature of the wafer can be made uniform.

It is sectional drawing which shows the electrostatic chuck apparatus of one Embodiment of this invention. It is sectional drawing which shows the modification of the electrostatic chuck apparatus of one Embodiment of this invention.

The form for implementing the electrostatic chuck apparatus of this invention is demonstrated based on drawing.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

FIG. 1 is a cross-sectional view showing an electrostatic chuck device according to an embodiment of the present invention. This electrostatic chuck device 1 is a ceramic having an upper surface (one main surface) 2a as a mounting surface on which a wafer W is mounted. An electrostatic chuck portion 4 is constituted by the plate-like body 2 and the electrostatic chucking electrode 3 provided on the lower surface (other main surface) 2 b side of the ceramic plate-like body 2.
A sheet-like or film-like insulating layer 6 is bonded to the electrostatic adsorption electrode 3 via a sheet-like or film-like (first) organic adhesive layer 5, and the sheet-like or film-like insulating layer 6 is attached. A base portion (base) 8 that supports the electrostatic chuck portion 4 and cools the wafer W is bonded to the insulating layer 6 and the electrostatic chuck portion 4 via the (second) organic adhesive layer 7. Has been.

Hereinafter, the electrostatic chuck device 1 will be described in detail.
The ceramic plate-like body 2 is a disc-like one made of ceramics whose upper surface 2a is a mounting surface on which various wafers W such as silicon wafers are placed, and is made of an insulating ceramic sintered body.
This ceramic is not particularly limited as long as it has a volume resistivity of about 10 ¹³ to 10 ¹⁵ Ω · cm, mechanical strength, and durability against oxygen-based plasma and corrosive gas. For example, an alumina (Al ₂ O ₃ ) sintered body, an aluminum nitride (AlN) sintered body, an alumina (Al ₂ O ₃ ) -silicon carbide (SiC) composite sintered body, or the like is preferably used.
By using such ceramics, the plasma resistance against oxygen plasma and the corrosion resistance against corrosive gas are improved, the mechanical strength is also improved, and the generation of particles is suppressed.

  The thickness of the ceramic plate-like body 2 is preferably 0.3 mm or more and 2.0 mm or less. The reason is that if the thickness of the ceramic plate-like body 2 is less than 0.3 mm, the mechanical strength of the ceramic plate-like body 2 cannot be ensured, while the thickness of the ceramic plate-like body 2 is 2.0 mm. If it exceeds, the distance between the electrode surface and the adsorption surface increases, the adsorption force decreases, the heat capacity of the ceramic plate-like body 2 increases, and the heat exchange efficiency with the mounted wafer W decreases, This is because it becomes difficult to maintain the in-plane temperature of the wafer W in a desired temperature pattern.

The electrostatic chucking electrode 3 is used as an electrostatic chuck electrode for generating a charge and fixing the wafer W to the mounting surface of the ceramic plate-like body 2 by electrostatic chucking force. The shape and size are adjusted as appropriate.
As a material constituting the electrode 3 for electrostatic adsorption, metals such as gold (Au), silver (Ag) and copper (Cu) which are nonmagnetic materials, refractory metals such as titanium, tungsten, molybdenum and platinum, Carbon materials such as graphite and carbon, conductive ceramics such as silicon carbide (SiC), titanium nitride (TiN), titanium carbide (TiC), tungsten carbide (WC), TiC-Ni system, TiC-Co system, B ₄ C -Fe-based cermets and the like are preferably used. It is desirable that the thermal expansion coefficient of these materials is as close as possible to the thermal expansion coefficient of the ceramic plate-like body 2.

The thickness of the electrostatic adsorption electrode 3 is not particularly limited, but when used as a plasma generating electrode, it is preferably 0.1 μm or more and 100 μm or less, particularly preferably 5 μm or more and 20 μm or less. is there. The reason is that if the thickness is less than 0.1 μm, sufficient conductivity cannot be ensured. On the other hand, if the thickness exceeds 100 μm, the gap between the ceramic plate-like body 2 and the electrostatic adsorption electrode 3 cannot be ensured. Due to the difference in thermal expansion coefficient, cracks are likely to occur at the bonding interface between the ceramic plate-like body 2 and the electrostatic adsorption electrode 3, and the step between the electrode portion and the ceramic plate-like body is made to be a first organic material. This is because it cannot be covered with an adhesive and the insulation in the side surface direction decreases.
The electrostatic adsorption electrode 3 having such a thickness can be easily formed by a film forming method such as a sputtering method or a vapor deposition method, or a coating method such as a screen printing method.

The organic adhesive layer 5 is a sheet-like or film-like adhesive made of acrylic, epoxy, polyethylene, or the like, and is preferably a thermocompression-type organic adhesive sheet or film.
The reason is that an organic adhesive sheet or film of the thermocompression bonding type is placed on the electrostatic adsorption electrode 3, evacuated, and then thermocompression bonded to the electrostatic adsorption electrode 3. This is because bubbles and the like are not easily generated, and therefore are difficult to peel off, and the adsorption characteristics and voltage resistance characteristics of the electrostatic chuck portion 4 can be maintained well.

The thickness of the organic adhesive layer 5 is not particularly limited, but it is preferably 40 μm or more and 100 μm or less, more preferably 55 μm or more and 100 μm or less in view of adhesive strength, ease of handling, and the like.
If the thickness is 55 μm or more and 100 μm or less, the adhesion strength with the interface of the electrode is further improved, and the thickness of the organic adhesive layer 5 becomes more uniform. As a result, the ceramic plate and the base The thermal conductivity between the wafer and the wafer is made uniform, the cooling characteristics of the mounted wafer are made uniform, and the in-plane temperature of the wafer is made uniform.

  If the thickness of the organic adhesive layer 5 is less than 40 μm, the thermal conductivity between the electrostatic chuck portion 4 and the base portion 8 is improved, but the step of the electrode due to thermal softening of the adhesive layer is covered. It becomes difficult to peel off from the electrode interface, and if the thickness exceeds 100 μm, sufficient thermal conductivity between the electrostatic chuck portion 4 and the base portion 8 cannot be ensured. This is not preferable because the cooling efficiency is lowered.

  Thus, by using the organic adhesive layer 5 as a sheet-like or film-like adhesive, the thickness of the organic adhesive layer 5 is made uniform, and the gap between the ceramic plate-like body 2 and the base portion 8 is increased. The thermal conductivity becomes uniform. Therefore, the cooling characteristics of the wafer W are made uniform, and the in-plane temperature of the wafer W is made uniform.

The insulating layer 6 is a sheet-like or film-like insulating material made of an insulating resin that can withstand the applied voltage in the electrostatic chuck portion 2 such as polyimide, polyamide, aromatic polyamide, and the outer peripheral portion of the insulating layer 6 is The inner side of the outer periphery of the ceramic plate-like body 2 is set.
Thus, by providing the insulating layer 6 on the inner side of the ceramic plate-like body 2, the insulating layer 6 is improved in plasma resistance against oxygen-based plasma and corrosion resistance against corrosive gas, and suppresses generation of particles and the like. Is done.

The thickness of the insulating layer 6 is preferably 10 μm or more and 200 μm or less, more preferably 10 μm or more and 70 μm or less.
If the thickness of the insulating layer 6 is less than 10 μm, the insulation with respect to the electrode 3 for electrostatic attraction is lowered, the electrostatic attraction force is weakened, and the wafer W cannot be fixed to the mounting surface satisfactorily. On the other hand, if the thickness exceeds 200 μm, sufficient thermal conductivity between the electrostatic chuck portion 4 and the base portion 8 cannot be ensured, and the cooling efficiency decreases.

The organic adhesive layer 7 adheres and fixes the electrostatic chuck portion 4 and the insulating layer 6 to the base portion 8 and covers the electrostatic adsorption electrode 3, the organic adhesive layer 5 and the insulating layer 6. By being provided, it is intended to protect from oxygen-based plasma and corrosive gas, and is preferably a material having high plasma resistance, high thermal conductivity, and high cooling efficiency from the base portion 8, such as heat resistance, A silicone resin composition which is a resin excellent in elasticity is preferred.
This silicone resin composition is a silicon compound having a siloxane bond (Si—O—Si), and can be represented by, for example, a chemical formula of the following formula (1) or formula (2).

但し、Ｒは、Ｈまたはアルキル基（Ｃ_ｎＨ_２ｎ＋１−：ｎは整数）である。

Here, R is, H or an alkyl group _{(C n H 2n + 1 -} : n is an integer) is.

但し、Ｒは、Ｈまたはアルキル基（Ｃ_ｎＨ_２ｎ＋１−：ｎは整数）である。

Here, R is, H or an alkyl group _{(C n H 2n + 1 -} : n is an integer) is.

As such a silicone resin, it is particularly preferable to use a silicone resin having a thermosetting temperature of 70 ° C to 140 ° C.
Here, when the thermosetting temperature is lower than 70 ° C., when the electrostatic chuck portion 4 and the insulating layer 6 and the base portion 8 are joined, curing starts in the middle of the joining process, which hinders the joining work. On the other hand, if the thermosetting temperature exceeds 140 ° C., the difference in thermal expansion between the electrostatic chuck portion 4 and the insulating layer 6 and the base portion 8 cannot be absorbed, and the ceramic plate-like body 2 is preferable because not only the flatness on the mounting surface 2 is lowered, but also the bonding force between the electrostatic chuck portion 4 and the insulating layer 6 and the base portion 8 is lowered, and there is a possibility that peeling occurs between them. Absent.

The thermal conductivity of the organic adhesive layer 7 is preferably 0.25 W / mk or more, more preferably 0.5 W / mk or more.
Here, the reason why the thermal conductivity of the organic adhesive layer 7 is limited to 0.25 W / mk or more is that if the thermal conductivity is less than 0.25 W / mk, the cooling efficiency from the base portion 8 is lowered, and static This is because the wafer W placed on the upper surface 2a of the electric chuck portion 4 cannot be efficiently cooled.

The thickness of the second organic adhesive layer 7 is preferably 50 μm or more and 300 μm or less, more preferably 100 μm or more and 200 μm or less.
When the thickness of the second organic adhesive layer 7 is less than 50 μm, it becomes too thin, and as a result, sufficient adhesive strength cannot be secured, and the insulating layer 6 and the electrostatic chuck portion 4 and the base portion 8 are not secured. On the other hand, if the thickness exceeds 300 μm, sufficient thermal conductivity between the insulating layer 6 and the electrostatic chuck portion 4 and the base portion 8 cannot be ensured, and the cooling efficiency is improved. It is because it falls.

  Furthermore, by making the thermal conductivity of the organic adhesive layer 5 and the thermal conductivity of the insulating layer 6 equal to or lower than the thermal conductivity of the organic adhesive layer 7, the organic adhesive layer 7 Temperature variation, the variation in the in-plane temperature due to the variation in the thickness of the organic adhesive layer 7 can be reduced, and as a result, the temperature of the wafer W to be mounted can be made uniform. This is preferable because the in-plane temperature of the wafer W can be made uniform.

The organic adhesive layer 7 is a surface-coated nitride in which a coating layer made of silicon oxide (SiO ₂ ) is formed on the surface of a filler having an average particle size of 1 μm or more and 10 μm or less, for example, aluminum nitride (AlN) particles. It is preferable that aluminum (AlN) particles are contained.
The surface-coated aluminum nitride (AlN) particles are mixed to improve the thermal conductivity of the silicone resin, and the heat transfer rate of the organic adhesive layer 7 is controlled by adjusting the mixing rate. be able to.

The base portion 8 is for adjusting the temperature by cooling the electrostatic chuck portion 4 and adjusting it to a desired temperature pattern, thereby adjusting the temperature. The housing is connected to an external high-frequency power source (not shown). Inside the base portion 8, a flow path for circulating water for cooling or temperature adjustment and an insulating refrigerant is formed as necessary.
Further, a flow path for circulating a heat medium such as He gas or N ₂ gas may be formed between the adsorption surface and the wafer.

The material constituting the base portion 8 is not particularly limited as long as it is one of a metal excellent in thermal conductivity, conductivity, and workability, and a metal-ceramic composite material. For example, aluminum (Al), copper ( Cu), stainless steel (SUS) and the like are preferably used. The side surface of the base portion 8, that is, at least the surface exposed to plasma, is preferably coated with an alumite treatment or an insulating thermal spray material such as alumina or yttria.
In this base portion 8, at least the surface exposed to the plasma is subjected to an alumite treatment or an insulating film, so that the plasma resistance is improved and abnormal discharge is prevented. Will be improved. Moreover, since it becomes difficult for a surface to be damaged, generation | occurrence | production of a damage | wound can be prevented.

Next, a method for manufacturing the electrostatic chuck device 1 will be described.
First, the electrostatic chuck part 4 and the base part 8 are produced by a known method.
The electrostatic chuck unit 4 degreases and cleans the lower surface 2b of the ceramic plate-like body 2 using, for example, acetone, and coats the lower surface 2b with a film forming method such as a sputtering method or a vapor deposition method, or a screen printing method. It can obtain by forming the electrode 3 for electrostatic attraction using a construction method. The thickness of the ceramic plate-like body 2 is preferably increased in consideration of the grinding removal after the base portion 8 is bonded.

In addition, the base portion 8 is machined on any one of a metal and a metal-ceramic composite material, an alumite treatment or an insulating film is formed as necessary, and then degreased and cleaned using, for example, acetone. You can get it.
Next, a sheet-like or film-like organic adhesive and a sheet-like or film-like insulating material are prepared, and these are bonded together using a laminating apparatus and temporarily bonded, with a sheet-like or film-like organic adhesive. Use insulating material.

Next, this insulating material with an organic adhesive is die-cut into a smaller diameter than the ceramic plate-like body 2 using a press molding machine.
Next, the punched insulating material with an organic adhesive is attached to the electrostatic chucking electrode 3 of the electrostatic chuck portion 4 and is used under atmospheric pressure or 1 Pa using a thermocompression bonding apparatus such as a vacuum hot press machine. Under the following reduced pressure, pressurization (thermocompression bonding) is performed simultaneously with heating, and the organic adhesive layer 5 and the insulating layer 6 are thermocompression bonded onto the electrostatic chucking electrode 3 of the electrostatic chuck portion 4.

Next, the joint surface of the base portion 8 with the insulating layer 6 on the electrostatic chuck portion 4 is degreased and washed using, for example, acetone, and a silicone resin composition is used on the joint surface using, for example, a bar coater, Apply to a certain thickness.
Next, the insulating layer 6 on the electrostatic chuck portion 4 is placed on the coated surface, and the silicone resin composition is cured. Thereby, the cured body of the silicone resin composition becomes the organic adhesive layer 7.

Next, the upper surface 2a of the ceramic plate 2 is ground and the thickness of the ceramic plate 2 is adjusted to a desired thickness.
Finally, dot processing is performed on the upper surface 2a of the ceramic plate-like body 2 to obtain a mounting surface on which the wafer W is mounted.
As described above, the electrostatic chuck device 1 of the present embodiment can be obtained.

  FIG. 2 is a cross-sectional view showing a modification of the electrostatic chuck device of the present embodiment. The electrostatic chuck device 11 is different from the electrostatic chuck device 1 described above in that the lower surface of the electrostatic chucking electrode 3 and A sheet-like or film-like (first) organic adhesive layer 12 is formed so as to cover the side surface, and a sheet-like or film-like insulation is provided so as to cover the lower surface and the side surface of the organic adhesive layer 12. A base 13 is attached to the insulating layer 13 and the electrostatic chuck portion 4 that support the electrostatic chuck portion 4 and cool the wafer W via the organic adhesive layer 7. The point is that the part 8 is adhered.

This electrostatic chuck device 11 can also achieve the same effects as the electrostatic chuck device 1 described above.
In addition, a sheet-like or film-like organic adhesive layer 12 is formed so as to cover the lower surface and side surfaces of the electrostatic adsorption electrode 3, and the sheet is formed so as to cover the lower surface and side surfaces of the organic adhesive layer 12. Since the insulating layer 13 in the form of a film or film is adhered, the withstand voltage of the electrostatic adsorption electrode 3 can be improved.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.

"Example 1"
First, a ceramic plate _{2 made of} an Al ₂ O ₃ —SiC composite sintered body containing 8% by mass of SiC was prepared. The ceramic plate-like body 2 had a disk shape with a diameter of 298 mm and a thickness of 2 mm.
The lower surface of the ceramic plate-like body 2 is degreased and washed with acetone, and a conductive paste FC415 (manufactured by Fujikura Kasei Co., Ltd.) is applied to the lower surface using a screen printing method, and at 300 ° C. under atmospheric pressure. After baking for 10 hours, an electrode for electrostatic attraction having a thickness of 10 μm was formed to form an electrostatic chuck portion.

  Moreover, the base part which consists of aluminum by which the alumite process was given to the surface was prepared. The base portion had a disk shape with a diameter of 395 mm and a thickness of 29 mm.

Next, a polyimide film 200H (manufactured by Toray DuPont Co., Ltd.) having a thickness of 50 μm serving as an insulating layer and an epoxy thermal adhesive sheet having a thickness of 60 μm serving as an organic adhesive layer 5 are prepared. Was temporarily bonded at 80 ° C. to obtain an insulating film with an organic adhesive.
Next, this insulating film with an organic adhesive was die-cut into a smaller diameter than the ceramic plate-like body 2 using a molding machine.

Next, the die-insulated insulating film with an organic adhesive is attached to the electrostatic chucking electrode of the electrostatic chuck portion, and 160 ° C. and 5 MPa at a reduced pressure of 1 Pa or less using a vacuum hot press. Thermocompression bonding was performed under the conditions, and an insulating film with an organic adhesive was thermocompression bonded onto the electrostatic chucking electrode of the electrostatic chuck portion.
Since this insulating film with an organic adhesive was transparent to visible light, the presence or absence of bubbles could be easily confirmed.

Next, the bonding surface of the base portion with the electrostatic chuck portion is degreased and cleaned using acetone, and a silicon resin (AlN30v) containing 30% by volume of aluminum nitride (AlN) which is a silicone-based resin composition on the bonding surface. / V% -silicon resin) was applied with a thickness of 200 μm using a bar coater.
Next, an electrostatic chuck portion was placed on the coated surface, the AlN 30 v / v% -silicon resin was cured, and the base portion and the electrostatic chuck portion were bonded and fixed.
Next, the upper surface of the electrostatic chuck portion was ground and the thickness of the ceramic plate was adjusted to 0.5 mm.
Finally, dot processing was performed on the upper surface of the ceramic plate-like body to obtain a mounting surface on which the wafer is mounted, and the electrostatic chuck device of Example 1 was obtained.

In-plane variation in the thickness of the insulating film with an organic adhesive of this electrostatic chuck device was 2 μm.
Further, regarding the 10 electrostatic chuck devices thus produced, the variation in the thickness of the insulating film with an organic adhesive was determined to be 5 μm.

"Example 2"
An electrostatic chuck device of Example 2 was obtained in the same manner as Example 1 except that the epoxy thermal adhesive sheet having a thickness of 60 μm was replaced with an epoxy thermal adhesive sheet having a thickness of 100 μm.

In-plane variation in the thickness of the insulating film with an organic adhesive of this electrostatic chuck device was 2 μm.
Further, regarding the 10 electrostatic chuck devices thus produced, the variation in the thickness of the insulating film with an organic adhesive was determined to be 5 μm.

"Comparative example"
An electrostatic chuck device of a comparative example was obtained in the same manner as in Example 1 except that a silicone-based adhesive: AlN 30 v / v% -silicon resin was used instead of the punched thermal adhesive sheet.
In-plane variation of the thickness of the silicone adhesive layer of this electrostatic chuck device was 30 μm, which was larger than that of the electrostatic chuck devices of Examples 1 and 2.
Moreover, when the variation of the thickness of the silicone adhesive layer was determined for 10 electrostatic chuck devices, it was 50 μm, which was larger than the electrostatic chuck devices of Examples 1 and 2.

DESCRIPTION OF SYMBOLS 1 Electrostatic chuck apparatus 2 Ceramic plate-shaped body 2a Upper surface (one main surface)
2b Bottom surface (other main surface)
DESCRIPTION OF SYMBOLS 3 Electrode for electrostatic adsorption 4 Electrostatic chuck part 5 (1st) organic adhesive layer 6 Insulating layer 7 (2nd) organic adhesive layer 8 Base part (base)
11 Electrostatic chuck device 12 (First) organic adhesive layer 13 Insulating layer

Claims (3)

One main surface of the ceramic plate-shaped body is a mounting surface on which a wafer is placed, and the other main surface is provided with an electrostatic chuck electrode, and the ceramic provided on the other main surface side In an electrostatic chuck device comprising a base that supports a plate-like body,
The electrode for electrostatic attraction is covered with a sheet-like or film-like insulating layer via a sheet-like or film-like first organic adhesive layer, and a second organic-based adhesive is attached to this insulating layer. The base is bonded through the agent layer ,
The outer peripheral portion of the insulating layer is inside the outer peripheral portion of the ceramic plate-like body, and the outer peripheral portion of the insulating layer is covered with the second organic adhesive layer. Chuck device.   2. The electrostatic chuck device according to claim 1, wherein the first organic adhesive layer is a sheet-like or film-like organic adhesive layer attached by thermocompression bonding.   The thermal conductivity of the second organic adhesive layer is 0.25 W / mk or more, the thermal conductivity of the first organic adhesive layer, and the thermal conductivity of the sheet-like or film-like insulating layer. The electrostatic chuck apparatus according to claim 1, wherein is equal to or less than a thermal conductivity of the second organic adhesive layer.

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