JP6531675B2 - Electrostatic chuck device - Google Patents

Description

  The present invention relates to an electrostatic chuck device.

In the semiconductor manufacturing process, an electrostatic chuck device is used as a device for simply attaching and fixing a wafer to a sample stage and maintaining the wafer at a desired temperature in processing a wafer.
With the high integration and high performance of semiconductor devices, the processing of wafers is being miniaturized, and plasma etching technology which has high production efficiency and can be processed on a large area is often used. When the wafer fixed to the electrostatic chuck device is irradiated with plasma, the surface temperature of the wafer rises. Therefore, in order to suppress the rise of the surface temperature, a cooling medium such as water is circulated to the base of the electrostatic chuck device to cool the wafer from the lower side. At this time, the heat input to the wafer by plasma is performed. The variation in the wafer surface causes a temperature distribution in the surface of the wafer. For example, the temperature tends to be higher at the center of the wafer and lower at the edge.

For example, an electrostatic chuck device that adjusts the in-plane temperature distribution of a wafer using a gas such as helium or an electrostatic chuck device that adjusts the contact area between the wafer and the adsorption surface of the electrostatic chuck 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 the rapid temperature rise and fall of the heater, and the durability as the electrostatic chuck device is not good. There was a problem that it was enough.
In order to solve this problem, for example, when applied to a processing apparatus such as a plasma etching apparatus, the silicon accompanying the plasma application is generated by generating a local temperature distribution in the plane of a plate-like sample such as a silicon wafer. An electrostatic chuck device capable of performing local temperature control of a plate-like sample such as a wafer has been disclosed (see, for example, Patent Document 1).

JP, 2011-159684, A

In order to further suppress the variation in the in-plane temperature of the wafer, it is required to further improve the in-plane temperature uniformity of the electrostatic chuck unit for fixing the wafer.
An object of the present invention is to provide an electrostatic chuck device excellent in in-plane temperature uniformity of the electrostatic chuck portion, and to achieve the object.

The specific means for achieving the said subject are as follows.
<1> One main surface is a mounting surface on which a plate-shaped sample is to be mounted, and an electrostatic chuck unit incorporating an internal electrode for electrostatic adsorption and an opposite side to the mounting surface of the electrostatic chuck unit. A heating member bonded in a pattern having a gap on a surface, a first sheet material having a volume resistivity of 1000 Ω · cm or more, and a heat conductive layer having a thermal conductivity of 2 to 20 W / (m · K); The electrostatic chuck device includes a second sheet material having a volume resistivity of 1 Ω · cm or more and a base portion having a function of cooling the electrostatic chuck portion in this order.

  <2> The electrostatic chuck device according to <1>, wherein the heat conductive layer contains at least one selected from the group consisting of a metal, a metal oxide, and a metal nitride.

  <3> The electrostatic chuck device according to <1> or <2>, wherein the thicknesses of the first sheet material and the second sheet material are each independently 20 μm to 500 μm.

  <4> Any one of <1> to <3>, wherein the first sheet material and the second sheet material contain at least one selected from the group consisting of a silicone-based elastomer and a fluorine-based elastomer. The electrostatic chuck device according to

  <5> The electrostatic chuck device according to any one of <1> to <4>, wherein the Shore hardness (A) of the first sheet material is 10 to 70.

  According to the present invention, an electrostatic chuck device excellent in in-plane temperature uniformity of the electrostatic chuck portion is provided.

It is a cross-sectional schematic diagram which shows an example of the laminated structure of the electrostatic chuck apparatus of this invention. It is a cross-sectional schematic diagram which shows another example of the laminated structure of the electrostatic chuck apparatus of this invention.

<Electrostatic chuck device>
The electrostatic chuck device according to the present invention has an electrostatic chuck portion which has a main surface as a mounting surface on which a plate-like sample is mounted and which incorporates an internal electrode for electrostatic adsorption, and the electrostatic chuck portion described above. The heating member bonded in a pattern with a gap on the surface opposite to the mounting surface, the first sheet material with a volume resistivity of 1000 Ω · cm or more, and the thermal conductivity of 2 to 20 W / (m · K) A heat conduction layer, a second sheet material having a volume resistivity of 1 Ω · cm or more, and a base portion having a function of cooling the electrostatic chuck portion are provided in this order.
First, the laminated structure of the electrostatic chuck portion, the heating member, the sheet material, and the base portion in the electrostatic chuck device of the present invention will be described.

FIG. 1 is a schematic cross-sectional view showing an example of the laminated structure of the electrostatic chuck device of the present invention.
The electrostatic chuck device 100 includes a disk-like base having a thickness having a function of cooling the electrostatic chuck unit 2 for fixing a wafer, a heating member 50 for heating the electrostatic chuck unit 2, and the electrostatic chuck unit 2. And 10. Between the electrostatic chuck portion 2 and the base portion 10, in order from the electrostatic chuck portion 2 side, a heating member 50, a first sheet material 62 having a volume resistivity of 1000 Ω · cm or more, and a thermal conductivity of 2 to 2 It has the heat conduction layer 40 which is 20 W / (m · K) and the second sheet material 64 whose volume resistivity is 1 Ω · cm or more.

FIG. 2 is a schematic cross-sectional view showing another example of the laminated structure of the electrostatic chuck device of the present invention.
The electrostatic chuck device 102 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. And 10. Between the electrostatic chuck portion 2 and the base portion 10, sequentially from the electrostatic chuck portion 2 side, a heating member 50, a polymer material layer 30, a first sheet material 66 having a volume resistivity of 1000 Ω · cm or more, It has the heat conductive layer 40 whose thermal conductivity is 2 to 20 W / (m · K) and the second sheet material 64 whose volume resistivity is 1 Ω · cm or more.

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 portion 2 and is bonded to the electrostatic chuck portion 2 in a pattern having a gap. The heating member 50 can be configured, for example, by one or more patterns in which narrow band-like metal materials are meandered. Four heating members 50 are shown in FIGS. 1 and 2. These heating members 50 are usually connected in a single pattern, but may be composed of a plurality of identical or different patterns. For example, a plurality of annular heating members having different diameters may be arranged concentrically.
The heating member 50 can be fixed to the heating member installation surface by an adhesive, an adhesive or the like not shown in FIGS. 1 and 2.

The heat conductive layer 40 is a first sheet material 62 having a volume resistivity of 1000 Ω · cm or more, or a first sheet material 66 having a volume resistivity of 1000 Ω · cm or more, and a second sheet material having a volume resistivity of 1 Ω · cm or more. Of the sheet material 64 of the In general, the heat generated from the heating member 50 is transmitted in the vertical direction of the electrostatic chuck device 100 and is hardly diffused in the lateral direction of the electrostatic chuck device 100.
The vertical direction of the electrostatic chuck device 100 refers to a direction parallel to the perpendicular when the perpendicular is lowered from the electrostatic chuck portion 2 to the base portion 10, and the lateral direction of the electrostatic chuck device 100 is the same. It means the direction perpendicular to the perpendicular.
The heat conduction layer 40 has a function of diffusing the heat emitted from the heating member 50 in the lateral direction of the electrostatic chuck device 100. The heat conductive layer 40 preferably contains at least one selected from the group consisting of metals, metal oxides and metal nitrides. Specifically, a sheet in which one or two or more of metal particles, metal oxide particles, metal nitride particles and the like are dispersed in a binder resin may be used, or a metal plate may be used.

Each of the sheet material 62, the sheet material 64, and the sheet material 66 in FIGS. 1 and 2 is an insulating layer having a volume resistivity of 1 Ω · cm or more. A material having a thermal conductivity of 2 to 20 W / (m · K) generally has a high electrical conductivity, so that thermal conduction is performed to avoid conduction (short circuit failure) between the electrostatic chuck portion 2 and the base portion 10 The layer 40 is located between the sheet material 62 or 66, which is an insulating layer, and the sheet material 64. The sheet material 62 of FIG. 1 has a Shore hardness (A) of 10 to 70.
Hereinafter, a sheet material having a volume resistivity of 1 Ω · cm or more is referred to as an “insulating sheet material”.

The insulating sheet material may be soft or hard, but as in the case of the sheet material 62, by using a sheet material of a material having a low hardness of 10 to 70 in Shore hardness (A), electrostatic The place where the heating member 50 is located on the heating member installation surface of the chuck 2 is adjacent to the heating member 50 or the side surface of the heating member 50 and the place where the heating member 50 is not adjacent is adjacent to the electrostatic chuck 2.
Although the details of the method of manufacturing the electrostatic chuck device 100 will be described later, the electrostatic chuck device 100 has a sheet member 62 and a heat conduction layer 40 on the heating member installation surface side of the electrostatic chuck portion 2 to which the heating member 50 is fixed. The sheet material 64 can be stacked, and the electrostatic chuck portion 2 and the base portion 10 can be sandwiched and pressurized to manufacture. At this time, by using a sheet of a material having low hardness as the sheet material 62, the sheet material 62 embeds a gap between the heating members 50 and fixes the heating member 50 to the electrostatic chuck portion 2. Can.

In FIG. 1 and FIG. 2, the heat conduction layer is one layer and the insulating sheet material is two layers, but two or more heat conduction layers may be provided, and the number of insulating sheet materials is also three or more. May be However, from the viewpoint of avoiding conduction between the electrostatic chuck portion 2 and the base portion 10, the outermost layer of the laminate of the heat conductive layer and the insulating sheet material is preferably an insulating sheet material.
Specifically, when the heat conduction layer is A1, A2,..., And the insulating sheet material is B1 (first sheet material), B2 (second sheet material),.
(1) B1 / A1 / B2,
(2) B1 / A1 / B3 / A2 / B2,
(3) B1 / A1 / A2 / B2
Etc. can be mentioned.
In (2) and (3), among the two heat conduction layers, A1 may change the composition of the heat conduction layer, such as a metal plate and A2 a sheet containing heat conductive particles, etc. It may be aligned to a sheet or sheet containing thermally conductive particles to have the same composition.
The volume resistivities of the plurality of insulating sheets may be the same or different. For example, as shown in FIG. 1, when the unevenness formed by the heating member and the heating member installation surface is compensated by the sheet material, the first sheet material is used to avoid communication between the heating member and the heat conduction layer. It is conceivable to increase the volume resistivity by increasing the thickness. Further, as shown in FIG. 2, the unevenness formed by the heating member and the heating member installation surface is compensated by the polymer material layer, and when the polymer material layer has insulation, the first sheet material is made thinner , Volume resistivity can be reduced.

As shown in FIG. 2, the gap of the heating member 50 can also be embedded with the polymer material layer 30.
The polymer material layer 30 of FIG. 2 is adjacent to the heating member 50 or the side surface of the heating member 50 where the heating member 50 is located on the heating member installation surface of the electrostatic chuck 2 and where the heating member 50 is not present. It is adjacent to the electrostatic chuck 2. In FIG. 2, the polymer material layer 30 intervenes between the heating member 50 and the sheet member 66, and the sheet member 66 is not in contact with the heating member 50, but this configuration is only an embodiment of the present invention. . For example, the distance from the heating member installation surface of the electrostatic chuck 2 to the surface on the base 10 side of the heating member 50 and the heating member installation surface of the electrostatic chuck 2 to the surface on the base 10 side of the polymer material layer 30 The sheet material 66 may be in contact with both the heating member 50 and the polymer material layer 30 at the same distance.
When the gap or the gap and the upper portion of the heating member 50 are embedded with the polymer material layer 30, a hard (more than 70 Shore hardness) insulating sheet material can be used as the hard first sheet 66, or it is soft Insulating sheet materials can also be used (Shore hardness is 70 or less), and the range of choice of materials is expanded.
The laminated structure of the electrostatic chuck device of the present invention is not limited to the structure shown in FIGS.
Hereinafter, the reference numerals of the drawings are omitted.

[Thermal conduction layer]
The heat conductive layer has a thermal conductivity of 2 to 20 W / (m · K).
Substances with high thermal conductivity such as metal lumps have thermal conductivity of 50 W / (m · K) or more, but the thermal conductivity when mixed in the thermal conduction layer is 2 W / (m ····· K) or more is preferable, and 10 W / (m · K) or more is more preferable. The thermal conductivity of the thermal conduction layer can be measured by a vacuum constant measurement device TC-7000, manufactured by Vacuum Riko.
The heat conductive layer is at least one selected from the group consisting of metal, metal oxide and metal nitride as a heat conductive material from the viewpoint of achieving a heat conductivity of 2 to 20 W / (m · K) It is preferable to contain.
Examples of the metal include iron, copper, aluminum, zinc, tin and the like, and an alloy of these may be used. As the metal, one or more of the above can be used.
As the metal oxide, one or more of the oxides of the above metals can be used, and among them, aluminum oxide is preferable.
As the metal nitride, one or more of the above metal nitrides can be used, and among them, aluminum nitride is preferable.
Among metals, metal oxides and metal nitrides, metal oxides and metal nitrides are preferable, aluminum oxide and aluminum nitride are more preferable, and aluminum nitride is still more preferable.

When using a metal as a heat conductive material, a metal plate, metal foil, etc. can be used for a heat conductive layer.
Alternatively, the metal, the metal oxide and the metal nitride may be respectively formed into particles to form metal particles, metal oxide particles and metal nitride particles, and a sheet dispersed in a binder resin may be used as a heat conduction layer. More specifically, a binder resin such as an acrylic resin is dissolved in an organic solvent, and at least one thermally conductive particle of metal particles, metal oxide particles, and metal nitride particles is dispersed in a binder resin solution. After preparing the thermally conductive particle dispersion, the thermally conductive particle dispersion is applied to the surface of the insulating sheet material and the like, and then dried to obtain heat conduction as a resin sheet containing particles of the thermally conductive material. A layer is obtained.
The method for applying the thermally conductive particle dispersion to the surface to be applied is not limited to application, and application by screen printing, application by spin coating, application by spray, brush, application by bar coater, ejection by ink jet method, etc. Be After the application of the thermally conductive particle dispersion, it is preferable to heat the application surface of the thermally conductive particle dispersion to remove the solvent. Heating of the thermally conductive particle dispersion application surface may be performed according to the thickness of the thermally conductive layer, metal particles in the thermally conductive particle dispersion, metal oxide particles, metal nitride particles, concentration of binder resin and solvent, etc. Although it differs depending on the conditions, it is preferable to carry out at 80.degree. C. to 120.degree.

The layer thickness of the heat conductive layer is not particularly limited, and can be adjusted in the range in which the thermal conductivity is 2 to 20 W / (m · K). When a metal plate or metal foil is used as the heat conduction layer, the metal plate and the metal foil can have a thin layer thickness, for example, 5 to 20 μm because the heat conductivity is high.
When using the resin sheet containing heat conductive particles as a heat conductive layer, it can be 10-100 micrometers, for example.

[Insulating sheet material]
The electrostatic chuck device has two insulating sheet materials. Specifically, the first sheet material having a volume resistivity of 1000 Ω · cm or more and the second sheet material having a volume resistivity of 1 Ω · cm or more are included. The first sheet material and the second sheet material may be the same or different.
The insulating sheet material is provided in the electrostatic chuck device so as to sandwich the heat conductive layer in order to prevent conduction (short circuit failure) between the electrostatic chuck portion and the base portion due to the presence of the heat conductive layer. If the volume resistivity is 1000 Ω · m or more, it is generally recognized that there is electrical insulation. Since the electrostatic chuck device has the first sheet material having a volume resistivity of at least 1000 Ω · cm or more, the conduction between the electrostatic chuck portion and the base portion can be suppressed. The material can have a volume resistivity smaller than that of the first sheet material. In order to make the avoidance of conduction between the electrostatic chuck portion and the base portion more reliable, the volume resistivity of the second sheet material may be 1000 Ω · cm or more. The volume resistivity of the insulating sheet material is preferably 1000 Ω · cm or more for both the first sheet material and the second sheet material, and more preferably 10000 Ω · cm or more. The volume resistivity of the insulating sheet material is preferably as high as possible, and there is no particular upper limit, but it is larger than 1 × 10 ¹⁷ Ω · cm, and a member that can be used for an electrostatic chuck device can not be generally obtained.
The volume resistivity of the insulating sheet material can be measured by Hiresta-UX MCP-HT800 manufactured by Mitsubishi Chemical Analytech Co., Ltd.

The insulating sheet material is not particularly limited as long as it has a volume resistivity of 1000 Ω · cm or more for the first sheet material and 1 Ω · cm or more for the second sheet material. The elastic sheet material preferably functions as a member that relieves the stress caused by the temperature difference between the electrostatic chuck portion and the base portion. From this point of view, the insulating sheet material preferably contains any one selected from the group consisting of silicone elastomers and fluoroelastomers.
The silicone-based elastomer is mainly composed of organopolysiloxane, and can be divided into polydimethylsiloxane-based, polymethylphenylsiloxane-based and polydiphenylsiloxane-based. Some are partially modified with a vinyl group, an alkoxy group or the like. Specific examples thereof include KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), SE series, CY series, and SH series (manufactured by Toray Dow Corning Silicone Co., Ltd.).

As a 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 part or all of the hydrogen atoms of the hydrocarbon groups contained in the silicone-based elastomer are substituted with fluorine atoms And the like.
The insulating sheet material may contain a silicone-based elastomer or a fluorine-based elastomer alone, or may contain two or more, or one or more silicone-based elastomers and one or more fluorines. Both of the system elastomers may be included.

  The thickness of the insulating sheet material is preferably 20 μm to 500 μm for both the first sheet material and the second sheet material, from the viewpoint of expressing higher insulation. When the thickness of the insulating sheet material is 20 μm or more, the insulation property is enhanced, and the stress generated due to the temperature difference between the electrostatic chuck portion and the base portion can be easily relieved. A decrease in in-plane temperature uniformity of the chuck portion can be suppressed.

The Shore hardness (A) (JIS Z 2246: 2000) of the insulating sheet material is preferably 20 to 80 from the viewpoint of alleviating the stress caused by the temperature difference between the electrostatic chuck portion and the base portion.
Furthermore, when the Shore hardness (A) of the first sheet material is 10 to 70, the gap of the heating member can be embedded by the first sheet material, and the constituent material of the electrostatic chuck device is reduced. Can.
The Shore hardness (A) of the insulating sheet material is more preferably 30 to 80, and still more preferably 30 to 70.
In particular, the Shore hardness (A) of the first sheet material is more preferably 15 to 65, and still more preferably 20 to 60. When the Shore hardness (A) is 70 or less, the insulating sheet material easily follows the surface irregularities. Insulating sheet materials having a Shore hardness (A) of less than 10 can not be obtained.

[Electrostatic chuck]
The electrostatic chuck portion has one main surface as a mounting surface on which the plate-like sample is to be mounted, and incorporates an internal electrode for electrostatic adsorption.
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, a support plate integrated with the mounting plate and supporting the mounting plate An internal electrode for electrostatic adsorption provided between the mounting plate and the support plate and an insulating material layer (insulation material layer in the chuck) for insulating the periphery of the internal electrode for electrostatic adsorption and the support plate It is preferable that the power supply terminal be provided as described above and a power supply terminal for applying a DC voltage to the internal electrode for electrostatic adsorption.
In the electrostatic chuck portion, the surface adjacent to the first adhesive layer is the surface of the support of the electrostatic chuck portion.

The mounting plate and the support plate are disk-like members having the same shape of the superposed surface, and are aluminum oxide-silicon carbide (Al ₂ O ₃ -SiC) composite sintered body, aluminum oxide (Al ₂ O ₃ ) An insulating ceramic sintered body having mechanical strength such as a sintered body, an aluminum nitride (AlN) sintered body, or a yttrium oxide (Y ₂ O ₃ ) sintered body, and having durability against a corrosive gas and its plasma It is preferable that it is a thing consisting of a structure.
It is preferable that a plurality of protrusions having a diameter smaller than the thickness of the plate-like sample be formed on the placement surface of the placement plate, and the protrusions support the plate-like 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 device does not easily increase, and a predetermined in-plane temperature distribution can be easily obtained, so the heat capacity does not easily increase. And thermal responsiveness is unlikely to deteriorate.

The internal electrode for electrostatic adsorption is used as an electrode for electrostatic chuck for generating electric charge and fixing the plate-like sample by electrostatic adsorption force, and its shape and size are appropriately adjusted depending on the application. Be done.
The internal electrode for electrostatic adsorption is aluminum oxide-tantalum carbide (Al ₂ O ₃ -Ta ₄ C ₅ ) conductive composite sintered body, 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, aluminum nitride-tungsten (AlN-W) conductive composite sintered body, aluminum nitride-tantalum (AlN-Ta) conductive composite sintering It is formed of a conductive ceramic such as a body or a refractory metal such as tungsten (W), tantalum (Ta), or molybdenum (Mo).

The thickness of the internal electrode for electrostatic adsorption is not particularly limited, but is preferably 0.1 μm to 100 μm, and more preferably 5 μm to 20 μm. When the thickness of the internal electrode for electrostatic adsorption 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, and electrostatics The difference in thermal expansion coefficient with the internal electrode for adsorption does not easily increase, and a crack does not easily occur in the bonding 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 an evaporation method, or a coating method such as a screen printing method.

  The in-chuck insulating material layer encloses the internal electrode for electrostatic adsorption to protect the internal electrode for electrostatic adsorption from the corrosive gas and its plasma, and at the interface between the mounting plate and the support plate, that is, the electrostatic adsorption The outer peripheral area other than the internal electrode is joined and integrated. The in-chuck insulating material layer is preferably made of an insulating material having the same composition or main component as the material forming the mounting plate and the support plate.

  The power supply terminal is a rod-like terminal provided to apply a DC voltage to the electrostatic chucking internal electrode. The material of the power supply terminal is not particularly limited as long as it is a conductive material excellent in heat resistance, but the thermal expansion coefficient is similar to the thermal expansion coefficient of the internal electrode for electrostatic adsorption and the support plate Preferably, for example, conductive ceramics constituting an internal electrode for electrostatic adsorption, or metal materials such as tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb), Kovar alloy, etc. are suitably used. Used.

It is preferable that the power supply terminal is insulated from the base portion by an insulating insulator.
The feed terminal is joined and integrated to the support plate, and the mounting plate and the support plate are joined and integrated by the internal electrode for electrostatic adsorption and the insulating material layer in the chuck to form 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 adhered to the electrostatic chuck portion in a pattern having a gap via an adhesive or the like such as a silicone resin sheet.
The form of the heating member is not particularly limited, but is preferably a heater element consisting of two or more heater patterns independent of each other.
The heater element may be, for example, an inner heater formed at the center of the surface (heating member installation surface) opposite to the mounting surface of the electrostatic chuck portion, and an outer formed annularly at the periphery of the inner heater. It can be configured by two mutually independent heaters with the heater. Each of the inner heater and the outer heater has a pattern in which a narrow band-like metal material is meandered, repeatedly arranged around this axis about the central axis of the heating member installation surface, and adjacent patterns By connecting them, one continuous belt-like heater pattern can be obtained.
By controlling the inner heater and the outer heater independently, it is possible to control the in-plane temperature distribution of the plate-like sample fixed on the mounting surface of the mounting plate of the electrostatic chuck by electrostatic adsorption with high accuracy. it can.

The heater element is a nonmagnetic metal thin plate having a constant thickness of 0.2 mm or less, preferably 0.1 mm or less, for example, a titanium (Ti) thin plate, a tungsten (W) thin plate, a molybdenum (Mo) thin plate, etc. It is preferable to form by etching processing to a desired heater pattern by the lithography method.
When the thickness of the heater element is 0.2 mm or less, the pattern shape of the heater element is not easily reflected as the temperature distribution of the plate-like sample, and the in-plane temperature of the plate-like sample can be easily maintained in a desired temperature pattern.
Further, when the heater element is formed of nonmagnetic metal, the heater element does not easily generate heat by high frequency even if the electrostatic chuck device is used in a high frequency atmosphere, and the in-plane temperature of the plate-like sample is desired constant temperature or constant temperature It becomes easy to maintain the pattern.
In addition, when the heater element is formed using a nonmagnetic metal thin plate having a certain thickness, the thickness of the heater element becomes constant over the entire heating surface, and the amount of heat generation also becomes constant over the entire heating surface. The temperature distribution on the mounting surface can be made uniform.

[Polymer material layer]
The electrostatic chuck device may have a polymeric material layer that fills the gap of the heating member.
Of the surface (heating member installation surface) opposite to the mounting surface of the electrostatic chuck portion, the layer thickness in the stacking direction of the electrostatic chuck device of the polymer material layer positioned on the surface on which the heating member is not provided is And at least the same thickness as the shortest distance from the heating member installation surface to the surface on the first sheet material side of the heating member. When covering the heating member surface (the first sheet material side surface of the heating member) with the polymer material layer, the layer thickness of the polymer material layer on the heating member surface (the first surface of the heating member from the heating member installation surface) From the viewpoint of the in-plane temperature uniformity of the electrostatic chuck portion, the distance (d) to the sheet material side surface of (1) is preferably 1 μm to 100 μm, and more preferably 1 μm to 25 μm.

Examples of polymer materials that can constitute the polymer material layer include heat-resistant resins such as polyimide resins, silicone adhesives (silicone rubber), silicone resins, fluorocarbon resins, RTV (Room Temperature Vulcanizing) rubbers, fluorosilicone rubbers, etc. It can be mentioned. These may use only 1 type and may use 2 or more types.
Among the above, from the viewpoint of heat resistance, heat resistant resins such as polyimide resins, silicone adhesives, fluorine resins, and fluorosilicone rubbers are preferable, and polyimide resins, silicone adhesives, and fluorine resins are more preferable. The silicone adhesive (silicone rubber) is preferably in liquid form.

[Base part]
The base portion has a function of cooling the electrostatic chuck portion, is a member for adjusting 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 and the like.
The shape of the base portion is not particularly limited, but is usually in the form of a thick disc. The base portion is preferably a water-cooled base or the like in which a flow path for circulating water is formed.
The material which comprises a base part is a metal excellent in thermal conductivity, electroconductivity, and processability, the composite material containing these metals, and ceramics. Specifically, for example, aluminum (Al), aluminum alloy, copper (Cu), copper alloy, stainless steel (SUS) and the like are suitably used. Preferably, at least the surface of the base portion exposed to plasma is subjected to an alumite treatment or an insulating film such as alumina is formed.

<Method of Manufacturing 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, and the electrostatic chuck portion, the heating member, the first sheet material, and the heat conduction layer The second sheet material and the base portion may be stacked in this order, and the electrostatic chuck portion and the base portion may be pressed by a hot press or the like to sandwich them, or an adhesive may be interposed between the layers to be adjacent to each other Layers may be adhered. When an adhesive is used, an adhesive sheet may be used, or a liquid adhesive may be used, but from the viewpoint of reducing the layer thickness of the adhesive layer, the adhesive and a solvent for dissolving the adhesive It is preferable to use a coating solution containing (hereinafter, referred to as a bonding solution).
In the manufacture of the electrostatic chuck device, it is preferable to previously fix the heating member on the heating member mounting surface of the electrostatic chuck portion with an adhesive or a pressure-sensitive adhesive.

  Also, as in the electrostatic chuck device shown in FIG. 2, the polymer material is embedded in the recess formed by the electrostatic chuck portion and the heating member, and the heights of the polymer material layer and the heating member are equalized, or the recess and the heating member Is coated with a polymeric material, and the surface of the polymeric material layer is preferably made flat.

  The heating member may fix one or more individual heating members on the heating member installation surface while leaving a space, or may attach a film-like or plate-like heating member on the heating member installation surface After application, a part of the heating member may be removed by etching or the like to expose the heating member installation surface to form a gap.

The insulating sheet material is preferably coated in advance with a bonding solution on one side or both sides.
When using a metal plate or metal foil as a heat conductive layer, it is preferable to apply | coat the solution for adhesion | attachment previously to the single side | surface or both surfaces of a metal plate.
Insulating sheet material to which an adhesive solution has been applied, metal plate or metal foil to which an adhesive solution has been applied, and insulating sheet material to which an adhesive solution has been applied. The electrostatic chuck device is obtained by sandwiching the laminated body obtained by laminating the layers in this order and pressing the laminated body by a hot press or the like.
When a resin sheet containing metal particles, metal oxide particles, and metal nitride particles is used as the heat conductive layer, the above-described heat conductive particle dispersion may be applied to the surface of the insulating sheet material. In this case, for example, it can be prescribed as follows. Among the surfaces of the insulating sheet material to be the first sheet material, the bonding solution is applied to the heating member side, and the thermally conductive particle dispersion is applied to the opposite surface. Of the surfaces of the insulating sheet material to be the second sheet material, the adhesive solution is applied to the base portion side, and the opposite surface is the thermally conductive particle dispersion liquid of the insulating sheet material to be the first sheet material The coated surfaces are adjacent to each other to form a laminate of the insulating sheet material and the heat conductive layer. Thereafter, the obtained laminate is sandwiched between the heating member-attached electrostatic chuck portion and the base portion, and is pressurized by a hot press or the like to obtain an electrostatic chuck device.

  A known adhesive can be used as the adhesive of the bonding solution, 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 silicone adhesive), a silicone adhesive (for example, SD 4580 PSA, SD 4584 PSA, SD 4585 PSA, SD 4587 L, manufactured by Toray Dow Corning, Inc. PSA, SD 4560 PSA etc., Momentive, silicone adhesives (eg, XE13-B3208, TSE3221, TSE3221S, TSE3261-G, TSE3281-G, TSE3281-G, TSE3221, TSE326, TSE326M, TSE325 etc.), silicone silicone resin Company silicone adhesive (for example, KE-1820, KE-1823, KE-1825, KE-1830, KE-1833, etc.) and the like.

  The bonding solution may contain 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.

The adhesive solution is preferably prepared in the range of 0.05% by mass to 5% by mass from the viewpoint of uniform application with a thin film. The concentration of the adhesive in the adhesive solution is more preferably 0.1% by mass to 1% by mass.
Furthermore, the bonding solution may contain a catalyst to promote the hydrolysis of the adhesive. Examples of the catalyst include hydrochloric acid, nitric acid, ammonia and the like, among which hydrochloric acid and ammonia are preferable.
From the viewpoint of preventing the catalyst from remaining in the electrostatic chuck device, the bonding solution preferably contains no catalyst, and as the adhesive, the reactive functional group is an epoxy group, an isocyanate group, an amino group, or mercapto. It is preferred to include an adhesive that is a group.

Moreover, it is preferable to use the solution for polymeric material layers containing the polymeric material and the solvent which melt | dissolves a polymeric material for formation of a polymeric material layer.
As a solvent for dissolving the polymer material, although depending on the type of the polymer material, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone etc. may be mentioned. For example, when using a polyimide resin as the polymer material, the solvent is methyl ethyl ketone Is preferred.
The concentration of the polymer material in the solution for the polymer material layer depends on the type of polymer material to be used, the method of applying the solution, etc. For example, in the case of application by spin coating, from the viewpoint of uniform application It is preferable to set it as mass%-5 mass%, and it is more preferable that it is 0.1 mass%-1 mass%. When the coating method is screen printing, the concentration of the polymer material in the solution for the polymer material layer is preferably 30% by mass to 70% by mass, from 40% by mass, from the viewpoint of printability. More preferably, it is 60% by mass.

  As a method for applying the solution for adhesion and the solution for the polymer material layer to the surface to be applied, application by screen printing, application by spin coating, spray, brushing, application by bar coater, ejection by ink jet method, etc. may be mentioned. Be After the application of the bonding solution and the solution for the polymer material layer, the solvent is preferably removed by heating the application surface of the solution. Heating of the solution application surface varies depending on the thickness of the adhesive layer or the polymeric material layer, the concentration or type of the adhesive or the polymeric material in the solution, etc., but at 80 ° C. to 120 ° C. for 30 seconds to 5 minutes It is preferable to carry out under the conditions.

Moreover, it is preferable to manufacture an electrostatic chuck part as follows.
First, a plate-like mounting plate and a support plate are produced from an aluminum oxide-silicon carbide (Al ₂ O ₃ -SiC) composite sintered body. In this case, the mixed powder containing the silicon carbide powder and the aluminum oxide powder is formed into a desired shape, and then fired, for example, at a temperature of 1600 ° C. to 2000 ° C. in a non-oxidizing atmosphere, preferably an inert atmosphere for a predetermined time By doing this, 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 to have a size and a shape that can be closely 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 made of a conductive composite sintered body, a method of forming the conductive ceramic powder into a desired shape, and performing pressure firing may be mentioned.

At this time, as the conductive ceramic powder used for the power supply terminal, a conductive ceramic powder made of the same material as the internal electrode for electrostatic adsorption is preferable.
Moreover, when the terminal for electric power feeding is made into a metal, the method etc. of forming by metal processing methods, such as a grinding method and powder metallurgy, etc. using a high melting metal are mentioned.

Next, a conductive material such as the above-mentioned conductive ceramic powder is dispersed in an organic solvent containing terpineol, ethyl cellulose and the like so as to be in contact with the feed terminal in a predetermined region of the surface of the support plate into which the feed terminal is fitted. A coating solution for forming an internal electrode for electrostatic adsorption is applied and dried to form an internal electrode forming layer for electrostatic adsorption.
As this application method, it is desirable to use a screen printing method or the like because it is necessary to apply a uniform thickness. As another method, a method of forming a thin film of the above refractory metal by vapor deposition or sputtering, an internal electrode for electrostatic adsorption by arranging a thin plate made of the above-mentioned conductive ceramic or refractory metal There is a method of forming a formed layer, and the like.

  In addition, in order to improve insulation, corrosion resistance and plasma resistance in the region other than the region where the internal electrode forming layer for electrostatic adsorption is formed on the support plate, the same composition or main as the mounting plate and the support plate An in-chuck insulator layer is formed that includes powder materials of the same composition. For example, a coating liquid in which an insulating material powder having the same composition or the same main component as the mounting plate and the support plate is dispersed in an organic solvent containing telepinol, ethyl cellulose, etc. It can form by apply | coating by printing etc. and drying.

Next, the mounting plate is stacked on the electrostatic adsorption internal electrode formation layer and the insulating material on the support plate, and then they are integrated by hot pressing under high temperature and high pressure. The atmosphere in this hot press is preferably vacuum or an inert atmosphere such as Ar, He, N ₂ or the like. The pressure is preferably 5 to 10 MPa, and the temperature is preferably 1600 ° C to 1850 ° C.

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

DESCRIPTION OF SYMBOLS 2 electrostatic chuck part 10 base part 40 heat conductive layer 50 heating member 62 1st sheet material 64 2nd sheet material 100 electrostatic chuck apparatus

Claims (5)

  An electrostatic chuck portion having one main surface as a mounting surface for mounting a plate-like sample and a built-in internal electrode for electrostatic adsorption, and a gap between the surface opposite to the mounting surface of the electrostatic chuck portion and the electrostatic chuck portion. And a first sheet material having a volume resistivity of 1000 Ω · cm or more, a thermally conductive layer having a thermal conductivity of 2 to 20 W / (m · K), and a volume resistivity An electrostatic chuck device comprising a second sheet material having a size of 1 Ω · cm or more and a base portion having a function of cooling the electrostatic chuck portion in this order.   The electrostatic chucking device according to claim 1, wherein the heat conductive layer contains at least one selected from the group consisting of metal, metal oxide and metal nitride.   The electrostatic chuck device according to claim 1, wherein a thickness of each of the first sheet material and the second sheet material is independently 20 μm to 500 μm.   The first sheet material and the second sheet material contain at least one selected from the group consisting of silicone elastomers and fluoroelastomers. Electrostatic chuck device.   The electrostatic chuck device according to any one of claims 1 to 4, wherein the Shore hardness (A) of the first sheet material is 10 to 70.