JP6642170B2 - Electrostatic chuck device and manufacturing method thereof - Google Patents

Description

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

2. Description of the Related Art In a semiconductor manufacturing process, an electrostatic chuck device is used as a device for easily mounting and fixing a wafer on a sample stage and maintaining the wafer at a desired temperature when processing the wafer.
With the high integration and high performance of semiconductor elements, the processing of wafers has been miniaturized, and a plasma etching technique which has high production efficiency and enables fine processing of a large area is often used. When plasma is irradiated to a wafer fixed to the electrostatic chuck device, the surface temperature of the wafer increases. Therefore, in order to suppress the rise in the surface temperature, a cooling medium such as water is circulated through the base portion of the electrostatic chuck device to cool the wafer from below. At this time, heat input to the wafer by plasma is performed. Due to the variation in the wafer surface, a temperature distribution occurs in the wafer surface. For example, the temperature tends to be higher at the center of the wafer and lower at the edge.

For example, in an electrostatic chuck device that adjusts an in-plane temperature distribution of a wafer using a gas such as helium or an electrostatic chuck device that adjusts a contact area between a wafer and a suction surface of the electrostatic chuck, a local temperature It was difficult to control.
Further, in the conventional electrostatic chuck device with a heater function, cracks may occur in the electrostatic chuck portion, the base portion, and the heater itself due to rapid temperature rise and fall of the heater, and the durability of the electrostatic chuck device is not sufficient. There was a problem that it was enough.
In order to solve such a problem, for example, when applied to a processing apparatus such as a plasma etching apparatus, by generating a local temperature distribution in the plane of a plate-like sample such as a silicon wafer, the An electrostatic chuck device capable of locally controlling the temperature of a plate-like sample such as a wafer has been disclosed (for example, see Patent Document 1).

JP 2011-159684 A

Since the heating member for heating the electrostatic chuck portion is usually bonded with a gap to the surface of the electrostatic chuck portion opposite to the surface on which the plate-like sample is placed, the heating member and the heating member are As a result, the heating member could not be fixed stably.
An object of the present invention is to provide an electrostatic chuck device in which a heating member is stably fixed to a surface of the electrostatic chuck portion opposite to a surface on which a plate-shaped sample is placed, and a method for manufacturing the same. The task is to achieve it.

Specific means for achieving the above object are as follows.
<1> One principal surface is a mounting surface on which a plate-shaped sample is mounted, and an electrostatic chuck unit having a built-in electrostatic chuck internal electrode, and an electrostatic chuck unit on the opposite side to the mounting surface described above. A heating member bonded in a pattern having a gap on a surface, a sheet material filling the gap between the heating members, and a base portion having a function of cooling the electrostatic chuck portion are provided in this order, and the sheet material includes The electrostatic chuck device has a Shore hardness (A) of 10 to 70.

  <2> The electrostatic chuck device according to <1>, wherein the sheet material contains at least one selected from the group consisting of a silicone-based elastomer and a fluorine-based elastomer.

  <3> The electrostatic chuck device according to <1> or <2>, wherein the entire volume of the gap between the heating members is 10% by volume to 50% by volume of the volume of the sheet material.

  <4> The electrostatic chuck device according to any one of <1> to <3>, wherein a storage elastic modulus E ′ of the sheet material is 1 to 10 MPa in a temperature range of 0 to 200 ° C.

<5> The method for manufacturing an electrostatic chuck device according to any one of <1> to <4>,
One main surface is a mounting surface on which the plate-shaped sample is mounted, and is bonded in a pattern having a gap to a surface opposite to the mounting surface described above of the electrostatic chuck portion having the internal electrode for electrostatic chuck. Forming a heating member, and
The surface of the electrostatic chuck portion on which the heating member is formed and a sheet material having a layer thickness of 50 to 300 μm and a Shore hardness (A) of 10 to 70 are opposed to each other to form the electrostatic chuck portion. And a base unit having a function of cooling the electrostatic chuck unit.

  According to the present invention, there is provided an electrostatic chuck device in which a heating member is stably fixed to a surface of the electrostatic chuck portion opposite to a surface on which a plate-shaped sample is placed, and a method of manufacturing the same.

It is a cross section showing an example of the lamination composition of the electrostatic chuck device of the present invention. It is a schematic diagram for demonstrating the structure of the heating member of the laminated body manufactured by the Example and the comparative example, and the space | interval of heating members. It is explanatory drawing for demonstrating the evaluation method of the embedding state of the clearance gap of the heating member of an Example and a comparative example. It is explanatory drawing for demonstrating the evaluation method of the embedding state of the clearance gap of the heating member of an Example and a comparative example.

<Electrostatic chuck device>
The electrostatic chuck device according to the present invention is configured such that one main surface is a mounting surface on which a plate-shaped sample is mounted, and an electrostatic chuck unit having a built-in internal electrode for electrostatic suction, and the electrostatic chuck unit described above. A heating member adhered in a pattern having a gap on the surface opposite to the mounting surface, a sheet material filling the gap between the heating members, and a base portion having a function of cooling the electrostatic chuck portion are provided in this order. The sheet material has a Shore hardness (A) of 10 to 70.
First, the laminated structure of the electrostatic chuck unit, the heating member, the sheet material, and the base unit in the electrostatic chuck device of the present invention will be described.

FIG. 1 is a schematic cross-sectional view showing an example of a laminated structure of the electrostatic chuck device of the present invention.
The electrostatic chuck device 100 includes an electrostatic chuck unit 2 for fixing a wafer, a heating member 50 for heating the electrostatic chuck unit 2, and a thick disk-shaped base having a function of cooling the electrostatic chuck unit 2. A part 10. A heating member 50, a sheet material 20, and an insulating material layer 60 are provided between the electrostatic chuck 2 and the base 10 in this order from the electrostatic chuck 2 side.

  The heating member 50 is located on a surface (referred to as a heating member installation surface) opposite to the mounting surface of the electrostatic chuck unit 2 via an adhesive, an adhesive, or the like (not shown). Glued in a pattern with gaps. The heating member 50 can be configured by, for example, one or a plurality of patterns in which a narrow band-shaped metal material is meandering. FIG. 1 shows four heating members 50. These heating members 50 are generally connected in one pattern, but may be formed by a plurality of same or different patterns. For example, a plurality of ring-shaped heating members having different diameters may be arranged concentrically.

Since the sheet material 20 in FIG. 1 has a Shore hardness (A) of 10 to 70, it follows the shape of the gap of the heating member 50. Therefore, a place where the heating member 50 is located on the heating member installation surface of the electrostatic chuck unit 2 is adjacent to the heating member 50 or a side surface of the heating member 50, and a place where the heating member 50 is not located is adjacent to the electrostatic chuck unit 2. ing.
Although the details of the method of manufacturing the electrostatic chuck device will be described later, the electrostatic chuck device includes a sheet material 20 and an insulating material, if necessary, on the heating member installation surface side of the electrostatic chuck portion 2 to which the heating member 50 is fixed. It can be manufactured by sandwiching the electrostatic chuck portion 2 and the base portion 10 with the layer 60 interposed therebetween and applying pressure. At this time, by using a sheet of a low hardness material having a Shore hardness (A) of 10 to 70 as the sheet material 20, a part of the sheet material 20 moves fluidly and the heating members 50 Since it enters the gap and buries the unevenness generated by the electrostatic chuck 2 and the heating member 5, the heating member 50 can be stably fixed to the heating member installation surface of the electrostatic chuck 2. The Shore hardness (A) of the sheet material can be measured by, for example, a durometer GS-706 manufactured by Teklock.

  Further, the total volume of the gap of the heating member 50 (hereinafter sometimes referred to as “gap ratio”) is preferably 50% by volume or less of the volume of the sheet material 20. When the volume is 50% by volume or less, the thickness of the sheet material 20 that is not buried in the gap between the heating members 50 is secured, and the heating member 50 and the insulating material layer 60 (when the insulating material layer 60 is not provided, The proximity to the base portion 10) can be suppressed, and the stress caused by the temperature difference between the electrostatic chuck portion and the base portion can be reduced. In general, the gap ratio is likely to be 10% by volume or more due to the structural limitation of the electrostatic chuck device.

Further, the electrostatic chuck device 100 of FIG. 1 has an insulating material layer 60 between the sheet material 20 and the base portion 10. In FIG. 1, the insulating material layer 60 is provided at a position adjacent to the base portion 10, but the insulating material layer 60 may be provided, for example, between the heating member 50 and the electrostatic chuck portion 2. Then, it may be provided both between the sheet member 20 and the base portion 10 and between the heating member 50 and the electrostatic chuck portion 2.
The stacking configuration of the electrostatic chuck device of the present invention is not limited to the configuration shown in FIG.
Hereinafter, the description will be made with the reference numerals in the drawings omitted.

[Sheet material]
The sheet material has a Shore hardness (A) (JIS Z 2246: 2000) of 10 to 70.
A sheet material having a Shore hardness (A) of less than 10 is not available, and a sheet material having a Shore hardness of more than 70 has poor followability to surface irregularities and is not excellent in adhesion to an electrostatic chuck portion and a heating member. . The shore hardness (A) of the sheet material is preferably from 15 to 65, and more preferably from 20 to 60.
Since the sheet material is a material having a low hardness as described above, when the sheet material is sandwiched between the electrostatic chuck portion to which the heating member is fixed and the base portion, a part of the sheet material flows. Into the gap between the heating members to fix the heating member to the electrostatic chuck portion.
The sheet material is preferably not elastically deformed like chewing gum, but is an elastic material. Specifically, the storage elastic modulus E ′ of the sheet material is preferably 1 to 10 MPa in a temperature range of 0 to 200 ° C., and more preferably 2 to 8 MPa. When E ′ is 1 MPa or more, plastic deformation is difficult, and when E ′ is 10 MPa or less, the shore hardness (A) of the sheet material is easily reduced to 70 or less.
The storage elastic modulus E 'of the sheet material can be measured based on the test method of plastic dynamic mechanical properties in JIS K 7244 (1999).

In the present invention, the sheet material has a function of burying the gap between the heating members and stably fixing the heating member, and also has a function of relaxing stress caused by a temperature difference between the electrostatic chuck portion and the base portion. obtain.
From the viewpoint of relaxing the stress caused by the temperature difference between the electrostatic chuck portion and the base portion, the sheet material preferably contains at least one selected from the group consisting of a silicone-based elastomer and a fluorine-based elastomer.
Silicone-based elastomers contain organopolysiloxane as a main component and are classified into polydimethylsiloxane-based, polymethylphenylsiloxane-based, and polydiphenylsiloxane-based elastomers. Some are partially modified with vinyl groups, alkoxy groups and the like. Specific examples include the KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), SE series, CY series, and SH series (all manufactured by Toray Dow Corning Silicone Co., Ltd.).

As the fluorine-based elastomer, an elastomer having a structure in which the hard segment is a fluorine-based resin and the soft segment is a fluorine-based rubber, and some or all of the hydrogen atoms of the hydrocarbon groups contained in the silicone-based elastomer are replaced with fluorine atoms And the like.
The sheet material may contain a silicone-based elastomer or a fluorine-based elastomer alone, or may contain two or more kinds, or one or more silicone-based elastomers and one or more fluorine-based elastomers May be included.

(Electrostatic chuck)
The electrostatic chuck section has one main surface as a mounting surface on which a plate-shaped sample is mounted, and has a built-in internal electrode for electrostatic suction.
More specifically, for example, a mounting plate whose upper surface is a mounting surface on which a plate-shaped sample such as a semiconductor wafer is mounted, and a supporting plate that is integrated with the mounting plate and supports the mounting plate. An inner electrode for electrostatic attraction provided between the mounting plate and the support plate and an insulating material layer (insulating material layer in the chuck) for insulating the periphery of the inner electrode for electrostatic attraction, and penetrating the support plate. It is preferable that the power supply terminal be provided with a power supply terminal that is provided as described above and applies a DC voltage to the internal electrode for electrostatic attraction.

The mounting plate and the support plate are disk-shaped and have the same superimposed surface shape, and are made of an aluminum oxide-silicon carbide (Al ₂ O ₃ —SiC) composite sintered body, aluminum oxide (Al ₂ O ₃ ). Insulating ceramics having mechanical strength such as sintered body, aluminum nitride (AlN) sintered body, yttrium oxide (Y ₂ O ₃ ) sintered body, and having durability against corrosive gas and its plasma. It is preferable that it is made of a union.
It is preferable that a plurality of protrusions having a diameter smaller than the thickness of the plate-shaped sample are formed on the mounting surface of the mounting plate, and the protrusions support the plate-shaped sample.

  The thickness of the electrostatic chuck portion (the total thickness of the mounting plate and the support plate) is preferably 0.7 mm to 5.0 mm. When the thickness of the electrostatic chuck portion is 0.7 mm or more, mechanical strength of the electrostatic chuck portion can be secured. When the thickness of the electrostatic chuck portion is 5.0 mm or less, the heat transfer in the lateral direction of the electrostatic chuck portion does not easily increase, and a predetermined in-plane temperature distribution is easily obtained, so that the heat capacity does not easily increase. , Heat responsiveness is not easily deteriorated. In addition, the lateral direction of the electrostatic chuck unit refers to a direction orthogonal to the stacking direction in the stacked configuration of the electrostatic chuck unit, the heating member, the sheet material, and the base unit as illustrated in FIG.

The internal electrode for electrostatic attraction is used as an electrode for electrostatic chuck for generating electric charge and fixing a plate-like sample by electrostatic attraction force, and its shape and size are appropriately adjusted according to its use. Is done.
Internal electrodes for electrostatic attraction, aluminum oxide - tantalum carbide _{(Al 2 O 3 -Ta 4 C} 5) conductive composite sintered body, an aluminum oxide - tungsten _{(Al 2} O 3 -W) conductive composite sintered body, aluminum oxide - silicon carbide _{(Al 2} O 3 -SiC) conductive composite sintered body, an aluminum nitride - tungsten (AlN-W) conductive composite sintered body, an aluminum nitride - tantalum (AlN-Ta) conductive composite sintered It is formed of a conductive ceramic such as a body or a high melting point metal such as tungsten (W), tantalum (Ta), and molybdenum (Mo).

The thickness of the internal electrode for electrostatic attraction is not particularly limited, but is preferably 0.1 μm to 100 μm, more preferably 5 μm to 20 μm. When the thickness of the internal electrode for electrostatic attraction is 0.1 μm or more, sufficient conductivity can be secured, and when the thickness is 100 μm or less, the mounting plate and the support plate are The difference in thermal expansion coefficient between the internal electrode for adsorption and the internal electrode for adsorption is less likely to be large, and cracks are less likely to occur at the joint interface between the mounting plate and the support plate.
The internal electrode for electrostatic adsorption 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 insulating material layer in the chuck surrounds the internal electrode for electrostatic attraction, protects the internal electrode for electrostatic attraction from corrosive gas and its plasma, and at the boundary between the mounting plate and the support plate, that is, the electrostatic attraction. The outer peripheral region other than the internal electrode is joined and integrated. It is preferable that the in-chuck insulating material layer is made of the same composition or the same main component as the material forming the mounting plate and the support plate.

  The power supply terminal is a rod-shaped terminal provided for applying a DC voltage to the internal electrode for electrostatic attraction. The material of the power supply terminal is not particularly limited as long as it is a conductive material having excellent heat resistance, but a material whose thermal expansion coefficient is close to the thermal expansion coefficient of the internal electrode for electrostatic adsorption and the support plate is used. Preferably, for example, a conductive ceramic constituting the internal electrode for electrostatic adsorption, or a metal material such as tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb), and Kovar alloy is suitably used. Used.

The power supply terminal is preferably insulated from the base by an insulator having an insulating property.
The power supply terminal is joined and integrated with the support plate, and the mounting plate and the support plate are joined and integrated with the internal electrode for electrostatic attraction and the insulating material layer in the chuck to constitute an electrostatic chuck portion. Is preferred.

(Heating member)
The heating member is located on the surface opposite to the mounting surface of the electrostatic chuck portion, and is fixed to the electrostatic chuck portion via an adhesive, an adhesive, or the like in a pattern having a gap.
The form of the heating member is not particularly limited, but is preferably a heater element composed of two or more heater patterns independent of each other.
The heater element includes, for example, an inner heater formed at the center of a surface (heating member installation surface) opposite to the mounting surface of the electrostatic chuck portion, and an outer heater formed annularly outside a peripheral portion of the inner heater. It can be constituted by two mutually independent heaters. Each of the inner heater and the outer heater repeatedly arranges a pattern obtained by meandering a narrow band-shaped metal material around the central axis of the heating member installation surface around this axis, and connects adjacent patterns to each other. By connecting, one continuous belt-shaped heater pattern can be obtained.
By controlling the inner heater and the outer heater independently, it is possible to accurately control the in-plane temperature distribution of the plate-like sample fixed to the mounting surface of the mounting plate of the electrostatic chuck portion by electrostatic suction. it can.

The heater element is made of a non-magnetic metal sheet having a constant thickness of 0.2 mm or less, preferably 0.1 mm or less, for example, a titanium (Ti) sheet, a tungsten (W) sheet, a molybdenum (Mo) sheet, or the like. It is preferably formed by etching a desired heater pattern by a lithography method.
When the thickness of the heater element is 0.2 mm or less, the pattern shape of the heater element is less likely to be reflected as the temperature distribution of the plate-shaped sample, and the in-plane temperature of the plate-shaped sample is easily maintained at a desired temperature pattern.
In addition, when the heater element is formed of a non-magnetic metal, even when the electrostatic chuck device is used in a high-frequency atmosphere, the heater element is unlikely to generate heat by high frequency, and the in-plane temperature of the plate-like sample is maintained at a desired constant temperature or a constant temperature. It becomes easier to maintain the pattern.
In addition, if the heater element is formed using a non-magnetic metal thin plate having a constant thickness, the thickness of the heater element becomes constant over the entire heating surface, and the amount of generated heat becomes constant over the entire heating surface. The temperature distribution on the mounting surface can be made uniform.

(Insulating material layer)
The electrostatic chuck device preferably has an insulating material layer covering at least a part of the base portion.
Since the electrostatic chuck device of the present invention has a heating member for heating the electrostatic chuck portion, conduction (short circuit failure) between the electrostatic chuck portion and the base portion is suppressed, and the withstand voltage of the base portion is reduced. It is preferable to have an insulating material layer in order to improve the quality.
The insulating material layer may cover at least a part of the base portion, but is preferably a film-like or sheet-like layer covering the entire base portion.
Further, the position of the insulating material layer may be any position between the electrostatic chuck portion and the base portion, and may be composed of not only a single layer but also a plurality of layers. For example, an insulating material layer may be provided at a position adjacent to the base portion, between the heating member and the electrostatic chuck portion, or the like.
Among them, the insulating material layer is preferably provided between the heating member and the base portion and in a position close to the base portion from the viewpoint of ease of forming the insulating material layer.

When fixing the insulating material layer to the base portion, the insulating material layer is preferably fixed to the upper surface of the base portion via an adhesive. The adhesive used for fixing the insulating material layer (the adhesive for the insulating material layer) is not particularly limited, and is a heat-resistant and insulating sheet-like or film-like adhesive resin such as a polyimide resin, a silicone resin, and an epoxy resin. Can be used. The thickness of the adhesive for the insulating material layer is preferably from 5 μm to 100 μm, more preferably from 10 μm to 50 μm. The variation in the in-plane thickness of the adhesive for the insulating material layer is preferably within 10 μm from the viewpoint of improving the in-plane uniformity of the temperature control of the electrostatic chuck portion by the base portion.
From the viewpoint of adjusting the temperature of the electrostatic chuck portion, the thermal conductivity of the insulating material layer is preferably 0.05 W / mk or more and 0.5 W / mk or less, more preferably 0.1 W / mk or more and 0.25 W / mk. mk or less.

[Base]
The base portion has a function of cooling the electrostatic chuck portion, is a member for adjusting the temperature of the electrostatic chuck portion heated by the heating member to a desired temperature, and is a plate-like sample fixed to the electrostatic chuck portion. It also has the function of reducing the heat generated by etching or the like.
Although the shape of the base portion is not particularly limited, it is usually a thick disk. The base portion is preferably a water-cooled base or the like in which a flow path for circulating water is formed.
Materials constituting the base portion include metals having excellent thermal conductivity, conductivity, and workability, composite materials containing these metals, and ceramics. Specifically, for example, aluminum (Al), aluminum alloy, copper (Cu), copper alloy, stainless steel (SUS), or the like is suitably used. It is preferable that at least a surface of the base portion exposed to the plasma is subjected to an alumite treatment or an insulating film such as alumina is formed.

<Manufacturing method of electrostatic chuck device>
The manufacturing method of the electrostatic chuck device is not particularly limited as long as it can form the laminated structure of the electrostatic chuck device of the present invention. For example, the electrostatic chuck portion, the heating member, the sheet material, and the base portion are The electrostatic chuck portion and the base portion may be laminated in this order, and the electrostatic chuck portion and the base portion may be pressed and sandwiched by a hot press or the like, or the adjacent layers may be bonded to each other with an adhesive interposed between the respective layers.
The sheet material is inserted into the gap between the heating members, and the adhesion between the sheet material, the heating member and the electrostatic chuck portion is increased, and the heating member is placed on the opposite side of the electrostatic chuck portion from the mounting surface of the plate-like sample. From the viewpoint of facilitating stable fixing to the surface, it is preferable to use a sheet material having a layer thickness of 50 to 300 μm and a Shore hardness (A) of 10 to 70.

  That is, in the manufacturing method of the electrostatic chuck device, one main surface is set as a mounting surface on which the plate-shaped sample is mounted, and is opposite to the mounting surface described above of the electrostatic chuck portion having the internal electrode for electrostatic chuck. Forming a heating member adhered in a pattern having a gap to the surface of the electrostatic chuck portion, and a surface of the electrostatic chuck portion on which the heating member is formed, having a layer thickness of 50 to 300 μm and a Shore hardness ( A) a step of pressing the sheet material between 10 and 70 with the electrostatic chuck portion and a base portion having a function of cooling the electrostatic chuck portion, and pressing the sheet material. Is preferred.

When the layer thickness of the sheet material used in the manufacture of the electrostatic chuck device (layer thickness in a state where no external force is applied to the sheet material) is 50 μm or more, the stress caused by the temperature difference between the electrostatic chuck portion and the base portion When the thickness is 300 μm or less, a decrease in in-plane temperature uniformity of the electrostatic chuck portion can be suppressed.
The layer thickness of the sheet material is preferably 70 to 250 μm. The thickness of the sheet material can be measured, for example, with a film thickness VL-50A manufactured by Mitutoyo Corporation.
The shore hardness (A), material, and the like of the sheet material are as described above.

  When using an adhesive in the manufacture of the electrostatic chuck device, an adhesive sheet may be used, or a liquid adhesive may be used, but from the viewpoint of reducing the thickness of the layer provided with the adhesive, It is preferable to use a coating liquid (hereinafter, referred to as a bonding solution) containing an adhesive, water, and, if necessary, an organic solvent that dissolves the adhesive.

In manufacturing the electrostatic chuck device, it is preferable that the heating member is fixed in advance with an adhesive or the like on the heating member installation surface of the electrostatic chuck portion.
When the electrostatic chuck device is provided with an insulating material layer, it is preferable to fix the insulating material layer on the base portion with an adhesive (adhesive for the insulating material layer).
As for the heating member, one or a plurality of individual heating members may be fixed on the heating member installation surface while leaving an interval, or a film-like or plate-like heating member may be attached on the heating member installation surface. After attaching, a part of the heating member may be removed by etching or the like to form a gap.

It is preferable that the sheet material is preliminarily coated on one or both sides with an adhesive solution. An electrostatic chuck device can be obtained by sandwiching the sheet material to which the adhesive solution has been applied between the electrostatic chuck portion with the heating member and the base portion, and pressing the sheet material with a hot press or the like.
When the insulating material layer is provided on the electrostatic chuck device, a bonding solution is applied to one or both surfaces of the insulating material, and the sheet on which the bonding solution is applied is applied between the electrostatic chuck portion with the heating member and the base portion. An electrostatic chuck device with an insulating material layer can be obtained by arranging and sandwiching the insulating material coated with the material and the adhesive solution at an arbitrary position and pressing the insulating material with a hot press or the like.

  As the adhesive for the bonding solution, a known adhesive can be used, and various adhesives such as acrylic, epoxy, and silicone can be used. The adhesive may be a commercially available product. For example, as a silicone adhesive (including a silicone adhesive), a silicone adhesive (eg, SD 4580 PSA, SD 4584 PSA, SD 4585 PSA, SD 4587 L) manufactured by Dow Corning Toray Co., Ltd. PSA, SD 4560 PSA, etc.), manufactured by Momentive, silicone adhesives (eg, XE13-B3208, TSE3221, TSE3212S, TSE3261-G, TSE3280-G, TSE3281-G, TSE3221, TSE326, TSE326M, TSE325), Shin-Etsu Silicone And silicone adhesives (for example, KE-1820, KE-1823, KE-1825, KE-1830, KE-1833, etc.).

  The bonding solution may include an organic solvent that dissolves the adhesive. The organic solvent is not particularly limited as long as it can dissolve the adhesive, and includes, for example, at least one selected from the group consisting of alcohols and ketones. Examples of the alcohol include methanol, ethanol, and isopropyl alcohol, and examples of the ketone include acetone and methyl ethyl ketone.

It is preferable that the adhesive solution is prepared so that the concentration of the adhesive is in a range of 0.05% by mass to 5% by mass from the viewpoint of uniform application in a thin film. The concentration of the adhesive in the bonding solution is more preferably 0.1% by mass to 1% by mass.
Further, the bonding solution may include a catalyst to promote hydrolysis of the adhesive. Examples of the catalyst include hydrochloric acid, nitric acid, and ammonia, and among them, hydrochloric acid and ammonia are preferable.
From the viewpoint of suppressing the catalyst remaining in the electrostatic chuck device, the bonding solution preferably does not contain a catalyst, and as the adhesive, the reactive functional group is an epoxy group, an isocyanate group, an amino group, or a mercapto group. It is preferred to include a base adhesive.

Further, it is preferable that the electrostatic chuck portion is manufactured as follows.
First, aluminum oxide - to produce a plate-shaped mounting plate and the support plate by a silicon carbide _{(Al 2} O 3 -SiC) composite sintered body. In this case, a mixed powder containing the silicon carbide powder and the aluminum oxide powder is formed into a desired shape, and then fired at a temperature of, for example, 1600 ° C. to 2000 ° C. in a non-oxidizing atmosphere, preferably in an inert atmosphere, for a predetermined time. By doing so, a mounting plate and a support plate can be obtained.

Next, a plurality of fixing holes for fitting and holding the power supply terminals are formed in the support plate.
The power supply terminal is manufactured so as to have a size and a shape capable of being tightly fixed to the fixing hole of the support plate. As a method of manufacturing the power supply terminal, for example, when the power supply terminal is a conductive composite sintered body, a method of molding a conductive ceramic powder into a desired shape and firing it under pressure may be used.

At this time, the conductive ceramic powder used for the power supply terminal is preferably a conductive ceramic powder made of the same material as the internal electrode for electrostatic attraction.
When the power supply terminal is made of metal, a method using a metal having a high melting point, such as a grinding method or a metal working method such as powder metallurgy, may be used.

Next, a conductive material such as the above-mentioned conductive ceramic powder was dispersed in an organic solvent containing terpineol, ethyl cellulose, and the like so as to be in contact with the power supply terminal in a predetermined region of the surface of the support plate in which the power supply terminal was fitted. A coating solution for forming an internal electrode for electrostatic attraction is applied and dried to form a layer for forming an internal electrode for electrostatic attraction.
As this coating method, it is necessary to apply a uniform thickness, and therefore, it is preferable to use a screen printing method or the like. Other methods include a method of forming a thin film of the above-mentioned high melting point metal by a vapor deposition method or a sputtering method, and disposing a thin plate made of the above-mentioned conductive ceramics or a high melting point metal to form an internal electrode for electrostatic adsorption. There is a method of forming a formation layer.

  In addition, in order to improve insulation, corrosion resistance, and plasma resistance, a region other than the region where the electrostatic adsorption internal electrode forming layer is formed on the support plate has the same composition or main composition as the mounting plate and the support plate. The in-chuck insulating material layer containing the same powder material is formed. The insulating material layer in the chuck is, for example, a coating liquid obtained by dispersing an insulating material powder having the same composition or the same main component as the mounting plate and the support plate in an organic solvent containing terpinol, ethylcellulose, or the like, in a screen above the predetermined region. It can be formed by applying by printing or the like and drying.

Next, the mounting plate is superimposed on the electrostatic adsorption internal electrode forming layer on the support plate and the insulating material, and then these are integrated by hot pressing under high temperature and high pressure. Atmosphere in the hot press, vacuum or Ar, He, an inert atmosphere such as _{N 2} is preferable. The pressure is preferably 5 to 10 MPa, and the temperature is preferably 1600 ° C to 1850 ° C.

By this hot pressing, the electrostatic adsorption internal electrode forming layer is fired to become an electrostatic adsorption internal electrode formed of a conductive composite sintered body. At the same time, the support plate and the mounting plate are joined and integrated via the in-chuck insulating material layer.
Further, the power supply terminal is refired by hot pressing under a high temperature and a high pressure, and is tightly fixed to a fixing hole of the support plate.
Then, the upper and lower surfaces, outer periphery, gas holes, and the like of these joined bodies are machined to form an electrostatic chuck portion.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.
In the following Examples and Comparative Examples, a laminate similar to the laminate configuration of the electrostatic chuck device shown in FIG. 1 was prepared and evaluated.

<1. Configuration of Laminate of Examples and Comparative Examples>
The laminates of the example and some comparative examples have a configuration in which the electrostatic chuck 2, the heating member 50, the sheet material 20, and the base 10 in FIG. 1 are laminated in this order. However, the laminates of the example and the comparative example do not include the insulating material layer 60 in FIG. The laminate of Comparative Example 1 does not have a sheet material having a Shore hardness (A) of 10 to 70.

<2. Manufacture of laminated body>
A 100 μm-thick Ti foil (heating member) is laminated on a ceramic plate (Al ₂ O ₃ —SiC composite sintered body; electrostatic chuck portion) via an adhesive, and then the Ti foil is etched. Then, a part of the ceramic plate was exposed to form a Ti pattern in which ring-shaped Ti foils having different diameters were concentrically arranged.
FIG. 2 shows a schematic diagram of the Ti pattern. In FIG. 2, a Ti foil of a heating member is laminated on the electrostatic chuck portion up to the outer periphery 22 of the electrostatic chuck portion. Is divided into a heating member 52 and a heating member 54, and a gap 53 between the heating member 52 and the heating member 54 is formed in a concave shape.
A sheet material (silicone-based elastomer sheet) having a Shore hardness (A) and a layer thickness [μm] shown in Table 1 was laminated on a ceramic plate having an uneven surface formed by a Ti pattern, and further an aluminum jig (diameter 40 mm, The base portion 10) was laminated with a thickness of 2 cm, and a ceramic plate and an aluminum jig were stuck together and heated at 100 ° C. for 3 minutes to obtain a laminate. The sheet material used was a sheet material having one surface embossed and the other surface having no unevenness and a smooth surface. The laminated body was a ceramic plate having an embossed surface formed with an uneven surface by a Ti pattern. It is stuck so that it is adjacent to.
The Shore hardness (A) of the sheet material used in the examples and the comparative examples was measured by a durometer GS-706 manufactured by Teklock Corporation, and the thickness was measured by a film thickness VL-50A manufactured by Mitutoyo Corporation.

<3. Evaluation method>
The following evaluations were performed on the laminates of the examples and the comparative examples. Table 1 shows the results.
1. Embedded state of the gap between the heating members In the production of the laminates of the example and the comparative example, since no adhesive was interposed between the sheet material and the base portion, the sheet material stuck to the heating member and the electrostatic chuck portion Thus, the base portion could be easily peeled off. Further, since the sheet material was colorless and transparent, by observing the surface of the sheet material on the base portion side, it was possible to confirm the embedded state of the concave portion by the sheet material. The state of embedding of the gap between the heating members by the sheet material was evaluated by confirming an image obtained by enlarging the surface of the sheet material on the base portion side by 150 times with an optical microscope.
Since the surface of the sheet material on the heating member side is embossed and the other surface is smooth, if the sheet material is pressed by pressing and buried in the recess of the heating member, the emboss is crushed and the sheet material becomes transparent. Looks like. On the other hand, if the sheet material is not sufficiently buried in the concave portion of the heating member, the emboss does not collapse, and the sheet material appears cloudy due to irregular reflection of light.

FIG. 3 is an enlarged view of the gap 53 between the heating member 52 and the heating member 54 having the Ti pattern shown in FIG. FIG. 3 shows the heating member 152, the heating member 154, and the gap 153 between the heating member 152 and the heating member 154. The gap 153 has a concave shape, that is, a groove formed between the heating member 152 and the heating member 154.
FIG. 3 shows a straight line connected at any position of the gap 153 so that the width of the gap 153 is the shortest. In this straight line, one end of the gap 153 on the heating member 154 side is A, and one end of the gap 153 on the heating member 152 side is B.
FIG. 4 is a cross-sectional view of the gap between the heating members at the position of the straight line AB. In the gap 253 of the heating member, a sheet material 222 is embedded in a trapezoidal shape.

As described above, since the surface of the sheet material used in the example and the comparative example has an embossed surface pressed against the heating member, the wall surface of the gap 253 (see FIG. , The surface b of the sheet material 222 in the area pressed against the bottom surface looks transparent. On the other hand, the surface a and the surface c of the sheet material 222 in a region of the sheet material 222 that is not pressed against the bottom surface of the gap 253 appear cloudy due to irregular reflection of light due to embossed irregularities.
Gap width of the heating member, in FIGS. 3 and 4, of the length L of the straight line AB, the total length of the area where the sheet material appear cloudy (In FIG. 4, L ₁ and L ₂₎ ( In FIG. 4, L ₁ + L ₂ ) is defined as “empty wall portion”, and the ratio of the empty wall portion (in FIG. 4, 100 × (L ₁ + L ₂ ) / L) was calculated. The embedding state of the gap between the heating members by the sheet material was evaluated based on the calculated ratio of the empty wall portion according to the following evaluation criteria.

(Evaluation criteria)
A: The empty wall portion is 50% or less on a straight line connecting both ends of the concave portion.
B: The empty wall portion is more than 50% and less than 90% on a straight line connecting both ends of the concave portion.
C: On a straight line connecting both ends of the concave portion, the empty wall portion is 90% or more.

2. Storage modulus E 'of sheet material
The storage elastic modulus E ′ of the sheet material used in Examples and Comparative Examples was measured three times at room temperature (25 ° C.) using DMA-7100 manufactured by Hitachi High-Tech Science Corporation, and the average value is shown in Table 1. Was.
Table 1 shows the results.

3. Ratio of the total volume of the gap of the heating member to the volume of the sheet material (gap ratio)
The ratio of the total volume of the gap of the heating member to the volume of the sheet material was calculated from the volume of the sheet material used for manufacturing the laminates of the examples and the comparative examples and the total volume of the gap of the heating member. Table 1 shows the results. The total volume of the gap between the heating members was calculated from the height (thickness of the heating member) of the heating member, the width of the groove between the heating members, and the total length of the groove between the heating members. Further, the width and the total length of the groove between the heating members were calculated based on a photograph taken by enlarging the uneven surface of the heating member adhered with glass by 150 times with an optical microscope.

  As can be seen from Table 1, in the laminate using a sheet material having a Shore hardness (A) of 10 to 70, the sheet material enters the gap between the heating members, and the unevenness is buried. It was found that the unevenness of the heating member was embedded in the sheet material, so that the heating member was stably fixed to the electrostatic chuck.

2 electrostatic chuck section 10 base section 20 sheet material 50 heating member 60 insulating material layer 100 electrostatic chuck apparatus

Claims (4)

One main surface is a mounting surface on which a plate-shaped sample is mounted, and an electrostatic chuck portion having a built-in electrostatic chuck internal electrode, and a gap between the electrostatic chuck portion and the surface opposite to the mounting surface described above. a heating member which is bonded in a pattern having a sheet material filling the gap between the heating member and a base portion having a function of cooling the electrostatic chuck portion in the manufacturing method of an electrostatic chuck device Ru in this order So,
One main surface is a mounting surface on which the plate-shaped sample is mounted, and is bonded in a pattern having a gap to a surface opposite to the mounting surface described above of the electrostatic chuck portion having the internal electrode for electrostatic chuck. Forming a heating member, and
The surface of the electrostatic chuck portion on which the heating member is formed and a sheet material having a layer thickness of 50 to 300 μm and a Shore hardness (A) of 10 to 70 are opposed to each other to form the electrostatic chuck portion. And a base part having a function of cooling the electrostatic chuck part . The method according to claim 1, wherein the sheet material contains at least one selected from the group consisting of a silicone-based elastomer and a fluorine-based elastomer. Method for producing the total volume of the gap of the heating member, the electrostatic chuck apparatus according to claim 1 or claim 2 which is 10 vol% to 50 vol% of the volume of the sheet material. The method for manufacturing an electrostatic chuck device according to claim 1, wherein a storage elastic modulus E ′ of the sheet material is 1 to 10 MPa in a temperature range of 0 to 200 ° C. 5.