JP5982887B2 - Electrostatic chuck device - Google Patents

Description

  The present invention relates to an electrostatic chuck device. More specifically, even when used for a long time, the mounting surface on which a plate-like sample is placed is excellent in wear resistance and corrosion resistance. The present invention relates to an electrostatic chuck device that does not change over time in surface shape such as damage.

  In recent years, the semiconductor industry that supports IT technology, which has been rapidly progressing, has demanded higher integration and higher performance of devices. For this reason, even in semiconductor manufacturing processes such as plasma etching and plasma CVD, the fine processing technology has been improved. There is a need for improvement. In this semiconductor manufacturing process, a semiconductor manufacturing apparatus using plasma, such as a plasma etching apparatus or a plasma CVD apparatus, is used. Conventionally, in these semiconductor manufacturing apparatuses, a wafer is simply attached and fixed to a sample stage. In addition, an electrostatic chuck apparatus is used as an apparatus for maintaining the wafer at a desired temperature.

In such an electrostatic chuck device, in order to improve the wear resistance and corrosion resistance of a mounting surface on which a plate-like sample is mounted, a conductive substrate made of metal or metal and ceramic is used as an adsorption electrode, and this conductive There has been proposed an electrostatic chuck in which an insulating film is provided on one main surface of a conductive substrate, the upper surface thereof is used as a wafer mounting surface, and the insulating film is made of an amorphous ceramic made of oxide (Patent Document 1). reference).
In this electrostatic chuck, one main surface of the conductive substrate is roughened by blasting or the like, and the one main surface that has become the rough surface is sprayed with alumina, thereby adhering to the conductive substrate. A good thermal sprayed film is formed.
Further, in order to improve the adhesion, after the blasting process, a metal sprayed film is formed on one of the roughened main surfaces, and the above-mentioned sprayed film is formed on the metal sprayed film. ing.

JP 2004-349612 A

By the way, in the conventional electrostatic chuck described above, there is a problem that, when used for a long time, the sprayed film is peeled off on the mounting surface on which the plate-like sample is mounted, or the ceramic base material is easily damaged. . In particular, in the case of a sprayed film made of yttrium oxide (Y ₂ O ₃ ), there is a problem that even when the rough surface treatment is performed, the adhesion to the ceramic substrate is not sufficient, and peeling due to thermal expansion is particularly likely to occur. It was.

Such a problem is that the temperature of the mounting surface on which the plate-like sample is placed increases or decreases when the electrostatic chuck is used, such as an electrostatic chuck mounted on a plasma processing apparatus or an electrostatic chuck with a heater function. It is particularly likely to occur in fluctuating devices. Furthermore, when the ceramic substrate is roughened, there is a problem in that the ceramic substrate has microcracks caused by the rough surface treatment and the electric resistance characteristics deteriorate.
Further, since the electrostatic chuck requires insulation, there is a problem that it is not possible to employ a structure in which a metal sprayed film having conductivity is formed after blasting.

  The present invention has been made in view of the above circumstances, and is excellent in wear resistance and corrosion resistance of a mounting surface on which a plate-like sample is mounted, even when used for a long time. It is an object of the present invention to provide an electrostatic chuck device that does not change with time in the surface shape such as damage to the substrate.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have built an internal electrode for electrostatic adsorption in a ceramic substrate, and from one metal oxide through a middle layer on one main surface of the ceramic substrate. An electrostatic chuck portion having one principal surface of the sprayed coating as a mounting surface on which the plate-like sample is placed, and the electrostatic chuck portion provided on the other main surface of the electrostatic chuck portion. A cooling base portion for cooling the chuck portion, and if the intermediate layer is made of a mixture containing the metal oxide and the resin, the adhesion between the ceramic substrate and the thermal spray film made of the metal oxide In particular, even when the temperature of the mounting surface on which the plate-like sample is placed fluctuates up and down during use, it is difficult to cause peeling due to thermal expansion. If micro cracks occur or the electric resistance characteristics deteriorate Concern also finding that there is no, and have completed the present invention.

That is, in the electrostatic chuck device of the present invention, an internal electrode for electrostatic adsorption is built in a ceramic base, and a thermal spray film made of a metal oxide is formed on one main surface of the ceramic base via an intermediate layer, An electrostatic chuck portion in which one principal surface of the sprayed film is a placement surface on which a plate-like sample is placed, and a cooling base provided on the other principal surface of the electrostatic chuck portion to cool the electrostatic chuck portion The intermediate layer is made of a mixture of the metal oxide and the resin, and the intermediate layer contains the metal oxide in an amount of 50% by volume to 95% by volume, and 5% of the resin. % Or more and 50% by volume or less.

In this electrostatic chuck device, a thermal spray film made of a metal oxide is formed on one main surface of a ceramic substrate via an intermediate layer, and the intermediate layer is made of a mixture containing a metal oxide and a resin. The intermediate layer improves the adhesion between the ceramic substrate and the thermal spray film, and the thermal spray film is less likely to be peeled off due to the thermal expansion difference by relaxing the thermal expansion difference therebetween.
Therefore, even when used for a long time, the sprayed film does not peel off, and the surface shape does not change with time, such as damage to the ceramic substrate.
Further, by limiting the composition of the intermediate layer to the above range, the resistance to plasma and radicals (free radicals) is further improved.

The metal oxide is preferably yttrium oxide.
This yttrium oxide has high corrosion resistance against plasma and radicals (free radicals), and can maintain wear resistance and corrosion resistance even when used for a long time.

The resin preferably contains one or more selected from the group consisting of silicon resins, acrylic resins, and polyimide resins.
These silicone resins, acrylic resins, and polyimide resins have excellent resistance to plasma and radicals (free radicals), and even when used for a long time, they can be held well without wearing the intermediate layer. It is.

The ceramic substrate is preferably a composite sintered body containing aluminum oxide and silicon carbide.
By making the ceramic base material a composite sintered body containing aluminum oxide and silicon carbide, it has extremely high corrosion resistance against plasma and radicals (free radicals). Therefore, even when used for a long time, it has wear resistance and corrosion resistance. It can be held well.
In addition, the composite sintered body containing aluminum oxide and silicon carbide has a dielectric constant that is higher than that of a conventional sintered body made of aluminum oxide or an aluminum oxide sintered body formed with a sprayed film of yttrium oxide. It is high and can exhibit high adsorption power.

A heating member may be provided between the electrostatic chuck portion and the cooling base portion.
By providing a heating member between the electrostatic chuck part and the cooling base part, the in-plane uniformity of the temperature of the plate-like sample placed on one principal surface of the sprayed film, that is, the placing surface, is improved. In-plane uniformity of the plate-like sample such as plasma etching or plasma CVD is improved.

  According to the electrostatic chuck device of the present invention, a sprayed film made of a metal oxide is formed on one main surface of a ceramic substrate via an intermediate layer, and a plate-like sample is placed on the one main surface of the sprayed film. Since the intermediate layer is made of a mixture containing a metal oxide and a resin, the adhesion between the ceramic substrate and the sprayed film can be improved by the intermediate layer. There is no need to roughen one main surface of the material. Therefore, peeling of the sprayed film from the ceramic base material can be prevented over a long period of time, and the surface shape change such as damage of the ceramic base material can be prevented.

  Since the metal oxide is yttrium oxide, the corrosion resistance against plasma and radicals (free radicals) can be improved, and the wear resistance and corrosion resistance can be maintained for a long time.

  Since the resin includes one or more selected from the group of silicon resin, acrylic resin, and polyimide resin, the wear resistance and corrosion resistance of the intermediate layer are kept for a long time. be able to.

  Since the intermediate layer contains 50% by volume to 95% by volume of metal oxide and 5% by volume to 50% by volume of resin, the plasma and radicals (free radicals) of the intermediate layer are included. ) Can be further improved.

Since the ceramic base material is a composite sintered body containing aluminum oxide and silicon carbide, the corrosion resistance against plasma and radicals (free radicals) can be further improved, and the wear resistance and corrosion resistance are maintained for a long time. be able to.
In addition, the composite sintered body containing aluminum oxide and silicon carbide has a high dielectric constant and can exhibit high adsorption power.

  Since the heating member is provided between the electrostatic chuck portion and the cooling base portion, the in-plane uniformity of the temperature of the plate-like sample placed on the placement surface of the sprayed film can be improved. In-plane uniformity such as plasma etching and plasma CVD can be improved.

It is sectional drawing which shows the electrostatic chuck apparatus of the 1st Embodiment of this invention. It is sectional drawing which shows the electrostatic chuck apparatus of the 2nd Embodiment of this invention.

The form for implementing the electrostatic chuck apparatus of this invention is demonstrated.
The following embodiments are specifically described for better understanding of the gist of the invention, and do not limit the present invention unless otherwise specified.

[First Embodiment]
FIG. 1 is a cross-sectional view illustrating an electrostatic chuck device according to a first embodiment of the present invention. The electrostatic chuck device 1 includes an electrostatic chuck portion 2 and a cooling base portion 3.

The electrostatic chuck portion 2 includes a disk-shaped ceramic substrate 11, an intermediate layer 12 formed on an upper surface (one main surface) 11 a of the ceramic substrate 11, and an upper surface (one main surface) of the intermediate layer 12. The thermal spray film 13 made of a circular metal oxide is formed on the upper surface (one main surface: electrostatic attraction surface) 13a and is a mounting surface for mounting a plate-like sample W such as a semiconductor wafer. It is configured.
The ceramic substrate 11 includes a disk-shaped mounting plate 21, a disk-shaped support plate 22 disposed opposite to the lower surface (another main surface) of the mounting plate 21, and these mounting plates 21. The electrostatic chucking internal electrode 23 having a diameter smaller than that of the mounting plate 21 and the support plate 22 and the outer periphery of the electrostatic chucking internal electrode 23 is surrounded by the mounting plate 21 and the support plate 22. A ring-shaped insulating material layer 24 provided on the power supply terminal 25, a power supply terminal 25 that is connected to the central portion of the lower surface of the electrostatic attraction internal electrode 13 and applies a DC voltage, and covers the periphery of the power supply terminal 25. And a cylindrical insulator 26 that insulates.

Both the mounting plate 21 and the support plate 22 are preferably ceramics having heat resistance, such as aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ ), silicon nitride (Si ₃ N ₄ ), zirconium oxide. A sintered body composed of one kind selected from (ZrO ₂ ), sialon, boron nitride (BN), and silicon carbide (SiC), or a composite sintered body containing two or more kinds is preferred.

In particular, considering the corrosion resistance against plasma and radicals (free radicals) and the maintenance of wear resistance and corrosion resistance over a long period of time, a composition that has a particularly high dielectric constant and does not become an impurity with respect to the plate-like sample W that is electrostatically adsorbed is preferable For example, a silicon carbide-aluminum oxide composite sintered body containing aluminum oxide and silicon carbide is preferable.
Examples of the silicon carbide-aluminum oxide composite sintered body include a silicon carbide-aluminum oxide composite sintered body containing silicon carbide in an amount of 4 wt% to 20 wt%, with the balance being aluminum oxide.

The electrostatic adsorption internal electrode 23 is made of a plate-shaped conductive ceramic having a thickness of about 10 μm to 50 μm. The volume specific resistance value at the use temperature of the conductive ceramic constituting the electrostatic adsorption internal electrode 23 is preferably 1.0 × 10 ⁶ Ω · cm or less, more preferably 1.0 × 10 ⁴ Ω · cm. It is as follows.
Examples of the conductive ceramic include silicon carbide (SiC) -aluminum oxide (Al ₂ O ₃ ) composite sintered body, tantalum nitride (TaN) -aluminum oxide (Al ₂ O ₃ ) composite sintered body, and tantalum carbide (TaC). - aluminum oxide _(Al 2 _{O 3)} composite sintered body, molybdenum carbide _(Mo 2 C) - aluminum oxide _(Al 2 _{O 3)} include composite sintered body and the like.

The insulating material layer 24 is for joining and integrating the mounting plate 21 and the support plate 22 and protecting the electrostatic adsorption internal electrode 23 from plasma.
The material constituting the insulating material layer 24 is preferably an insulating material whose main component is the same as that of the mounting plate 21 and the supporting plate 22. For example, the mounting plate 21 and the supporting plate 22 are composed of a silicon carbide-aluminum oxide composite. In the case of a sintered body, aluminum oxide (Al ₂ O ₃ ) is preferable.

The intermediate layer 12 improves the adhesion between the ceramic substrate 11 and the sprayed film 13 and alleviates the difference in thermal expansion between them, and the sprayed film 13 is caused by the difference in thermal expansion from the ceramic substrate 11. It is provided for the purpose of preventing peeling.
This intermediate layer 12 is a region excluding a portion of the upper surface of the ceramic substrate 11 exposed to plasma and radicals (free radicals) from the peripheral portion to the inner annular region, for example, a portion 0.1 mm inward from the peripheral portion. Is formed.

The intermediate layer 12 is composed of a mixture containing a metal oxide and a resin.
Examples of the metal oxide include yttrium oxide, yttrium aluminum garnet, samarium oxide, dysprosium oxide, and the like. Here, yttrium oxide is most preferable in consideration of the high corrosion resistance against plasma and radicals (free radicals), and the ability to maintain wear resistance and corrosion resistance even when used for a long time.

  As the resin, it has excellent resistance to plasma and radicals (free radicals), and even when used for a long time, it is preferable to hold the intermediate layer well without being worn. For example, a silicon resin, an acrylic resin It is preferable to include one or more selected from the group of polyimide resins.

In particular, when oxygen-based plasma is used, a silicon-based resin that is excellent in plasma resistance against oxygen-based plasma is preferable.
This silicon resin is a resin excellent in heat resistance and elasticity, and is a silicon compound having a siloxane bond (Si—O—Si). This silicon-based resin can be represented by, for example, the following chemical formula (1) or (2).

但し、Ｒは、Ｈまたはアルキル基（ＣｎＨ２ｎ＋１−：ｎは整数）である。

However, R is H or an alkyl group (CnH2n + 1-: n is an integer).

但し、Ｒは、Ｈまたはアルキル基（ＣｎＨ２ｎ＋１−：ｎは整数）である。

However, R is H or an alkyl group (CnH2n + 1-: n is an integer).

As such a silicon-based resin, a silicon resin having a thermosetting temperature of 100 ° C. to 150 ° C. is particularly preferable.
Here, when the thermosetting temperature is lower than 100 ° C., when a mixture obtained by mixing a silicon-based resin and a metal oxide is applied and thermoset, the curing starts before thermosetting or at the initial stage of thermosetting. It is not preferable because it is inferior in properties. On the other hand, when the thermosetting temperature exceeds 150 ° C., the thermal expansion difference between the intermediate layer 12 and the ceramic base material 11 and the sprayed film 13 becomes large. As a result, the silicon-based resin is converted into the ceramic base material 11 and the sprayed film. Since the stress increases without being able to absorb the stress between the intermediate layer 12 and the intermediate layer 12 and the ceramic substrate 11 and the sprayed film 13 may be peeled off, it is not preferable.

Moreover, when using fluorine-type plasma, the acrylic resin excellent in plasma resistance with respect to fluorine-type plasma is preferable.
Examples of such acrylic resins include acrylic acid and its esters, methacrylic acid and its esters, acrylamide, acrylonitrile, and polymers or copolymers thereof.
Among these, in particular, polyacrylic acid esters such as polymethyl acrylate, polymethacrylic acid esters such as polymethyl methacrylate, and the like are preferably used.

This acrylic resin contains 1 to 50% by volume of vinyl acetate or vinyl butyrate, preferably 10 to 40% by volume, more preferably 20 to 30% by volume. It is preferable.
In this acrylic resin, by containing 1% by volume or more and 50% by volume or less of vinyl acetate or vinyl butyrate, the corrosion resistance of the acrylic resin to fluorine radicals is improved.
Moreover, the softness | flexibility of acrylic resin improves by containing 1 to 50 volume% of vinyl acetate or vinyl butyrate, As a result, the stress between the ceramic base material 11 and the sprayed film 13 further increases. Alleviated.

  The intermediate layer 12 preferably contains 50% by volume or more and 95% by volume or less of a metal oxide, and preferably contains 5% by volume or more and 50% by volume or less of a resin, more preferably a metal oxide. Is 85% by volume or more and 95% by volume or less, and the resin content is 5% by volume or more and 15% by volume or less.

Here, the reason why the respective contents of the metal oxide and the resin are in the above ranges is that these ranges improve the adhesion between the intermediate layer 12, the ceramic base material 11, and the sprayed film 13. This is because the difference in thermal expansion between the thermal spray film 13 and the thermal spray film 13 can be prevented from peeling off from the ceramic substrate 11 due to the thermal expansion difference.
Here, when the content of the metal oxide is less than 50% by volume or the content of the resin is more than 50% by volume, the ratio of the metal oxide in the intermediate layer 12 decreases, thereby causing plasma and radicals (free radicals). ) Is not preferred because the wear resistance and corrosion resistance cannot be maintained when used for a long time. On the other hand, when the metal oxide content exceeds 95% by volume or the resin content falls below 5% by volume, the ratio of the resin in the intermediate layer 12 decreases, thereby maintaining the intermediate layer 12 in a desired shape. It is not preferable because it becomes difficult to do.

The thickness of the intermediate layer 12 is preferably 100 μm or less, and more preferably 20 μm or less.
Here, the reason why the thickness of the intermediate layer 12 is set to 100 μm or less is that when the thickness exceeds 100 μm, the thickness change due to the curing shrinkage of the resin becomes too large, and the resulting intermediate layer 12 is caused by the curing shrinkage. There is a risk that a void will occur, and cracks, cracks, etc. may occur, and as the thickness of the intermediate layer increases, the distance from the electrostatic adsorption internal electrode 23 to the adsorption surface of the sprayed film 13 increases. This is because the adsorption force decreases.

The sprayed film 13 is a circular film formed by spraying a metal oxide on the intermediate layer 12 and having an upper surface 13a as a mounting surface for mounting a plate-like sample W such as a semiconductor wafer. .
This metal oxide is preferably the same as the metal oxide used for the intermediate layer 12.
Examples of the metal oxide include yttrium oxide, yttrium aluminum garnet, samarium oxide, dysprosium oxide, and the like, similar to the metal oxide used in the intermediate layer 12, corrosion resistance to plasma and radicals (free radicals), and long time. In consideration of wear resistance and corrosion resistance during use, yttrium oxide is most preferable.

The thickness of the sprayed film 13 is preferably 100 μm or less, and more preferably 50 μm or less.
Here, the reason why the thickness of the sprayed film 13 is set to 100 μm or less is that when the thickness exceeds 100 μm, the adsorption force decreases with an increase in the distance to the adsorption surface.

The cooling base portion 3 is provided below the electrostatic chuck portion 2 and controls the temperature of the electrostatic chuck portion 2 to a desired temperature and also has a high-frequency generating electrode. Aluminum (Al) , Aluminum alloy, copper (Cu), copper alloy, stainless steel (SUS), etc., with a thick disk shape made of a metal with good thermal conductivity, including water, organic solvents, etc. A flow path 31 for circulating the cooling medium is formed, and the temperature of the plate-like sample W placed on the upper surface 13a of the sprayed film 13 can be maintained at a desired temperature.
A power feeding terminal 25 and an insulator 26 are fixed in the through hole 32 formed in the cooling base portion 3.

It is preferable that at least the surface of the cooling base portion 3 exposed to the plasma is anodized or an insulating film such as alumina is formed.
The cooling base 3 has an alumite treatment or an insulating film formed on at least the surface exposed to the plasma, thereby improving plasma resistance and preventing abnormal discharge. The property is improved. Moreover, since it becomes difficult for a surface to be damaged, generation | occurrence | production of a damage | wound can be prevented.

The electrostatic chuck portion 2 and the cooling base portion 3 are bonded and fixed by an adhesive layer 4.
The shape of the adhesive layer 4 may be a cured film obtained by heating and curing a coating film applied with a liquid adhesive in addition to a sheet-like or film-like adhesive.
In consideration of workability such as alignment between the cooling base portion 3 and the electrostatic chuck portion 2, a sheet-like or film-like adhesive is preferable.

The adhesive layer 4 is, for example, 1 selected from the group of a silicon resin, an acrylic resin, and a polyimide resin in order to reduce the thermal expansion difference between the cooling base portion 3 and the electrostatic chuck portion 2. It is preferable to include seeds or two or more kinds.
In particular, from the viewpoint of heat resistance, plasma resistance, and heat transfer coefficient with the cooling base portion 3, an adhesive formed by adding an insulating heat conductive material such as an aluminum nitride (AlN) filler to a silicon-based adhesive is provided. preferable.

Next, a method for manufacturing the electrostatic chuck device 1 will be described.
First, the plate-like mounting plate 21 and the support plate 22 are made of ceramics having heat resistance such as a silicon carbide-aluminum oxide composite sintered body containing aluminum oxide and silicon carbide.
For example, when producing a silicon carbide-aluminum oxide composite sintered body, a mixture obtained by mixing aluminum oxide powder and silicon carbide powder at a predetermined blending ratio is formed into a desired shape, and then, for example, 1600 ° C to The mounting plate 21 and the support plate 22 can be obtained by baking for a predetermined time under a temperature of 1800 ° C. and a non-oxidizing atmosphere, preferably an inert atmosphere.

  Next, a fixing hole for fitting and holding the power supply terminal 25 is formed in the support plate 22. The method of drilling the fixed hole is not particularly limited, and can be drilled using, for example, a drilling method using a diamond drill, a laser machining method, an electric discharge machining method, an ultrasonic machining method, or the like. .

Next, the power supply terminal 25 has a size and a shape that can be fixed in close contact with the fixing hole of the support plate 22 by ordinary molding and pressure firing, or metal processing methods such as grinding and powder metallurgy. Make it.
For example, when the power supply terminal 25 is a conductive composite sintered body, a conductive ceramic powder made of the same material as the electrostatic adsorption internal electrode 23 is preferable. Further, when the power supply terminal 25 is a metal, a high melting point metal is preferable.
The power supply terminal 25 is refired at the time of subsequent hot pressing under high temperature and high pressure, is closely fixed to the support plate 22, and is integrally fitted.

Next, a conductive material such as the conductive ceramic powder is dispersed in an organic solvent such as terpinol so as to contact the power supply terminal 25 in a predetermined region on the surface of the support plate 22 in which the power supply terminal 25 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 coating method, it is desirable to use a screen printing method or the like because it is necessary to apply the film to a uniform thickness.

  Next, in order to improve insulation, corrosion resistance, and plasma resistance in a region outside the region where the electrostatic adsorption internal electrode forming layer is formed on the support plate 22, the mounting plate 21 and the support plate 22 Insulating material layers having the same composition or the same main component are formed. For example, when the mounting plate 21 and the support plate 22 are made of a silicon carbide-aluminum oxide composite sintered body, this insulating material layer is an aluminum oxide coating solution in which an aluminum oxide powder is dispersed in an organic solvent such as terpinol. Can be formed by applying to the predetermined area by screen printing or the like and drying.

Next, the mounting plate 21 is overlaid on the electrostatic adsorption internal electrode forming layer and the insulating material layer on the support plate 22, and then these are integrated by hot pressing under high temperature and high pressure. The atmosphere in this hot press is preferably a 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 pressing, the internal electrode forming layer for electrostatic adsorption is fired to become the internal electrode for electrostatic adsorption 23 made of conductive ceramics. At the same time, the support plate 22 and the mounting plate 21 are joined and integrated through the insulating material layer 24.
Further, the power supply terminal 25 is refired by hot pressing under high temperature and high pressure, and is firmly fixed to the fixing hole of the support plate 22.

On the other hand, a mixture for forming an intermediate layer for forming the intermediate layer 12 is prepared.
For example, a resin containing a metal oxide such as yttrium oxide, yttrium aluminum garnet, samarium oxide, dysprosium oxide, and one or more selected from the group consisting of silicon resin, acrylic resin, and polyimide resin, or A predetermined amount of each of the resin precursors is weighed and mixed using a mixer such as a ball mill or an automatic mortar to obtain a mixture for forming an intermediate layer.
If the resin or resin precursor is a low-viscosity solution, it only needs to be mixed with the metal oxide, but if the resin or resin precursor is a high-viscosity solution, an organic solvent is added to the metal oxide. It is preferable to adjust the viscosity of the mixture by mixing with the prepared metal oxide solution.

Next, the intermediate layer forming mixture is applied to a predetermined region on the mounting plate 21.
Examples of the method for applying the intermediate layer forming mixture include a screen printing method and a bar coating method. The screen printing method is preferable because it needs to be formed in a predetermined region on the mounting plate 21 with high accuracy.

Next, the intermediate layer forming mixture is heated and cured to form the intermediate layer 12.
Here, when the resin or resin precursor contained in the intermediate layer forming mixture is a thermosetting resin or a thermosetting resin precursor, the resin is cured by heating for a predetermined time at a temperature slightly higher than the thermosetting temperature.
When the resin or resin precursor contained in the intermediate layer forming mixture is an ultraviolet curable resin or an ultraviolet curable resin precursor, the resin is cured by irradiation with ultraviolet light having a light intensity necessary for ultraviolet curing for a predetermined time.
Instead of the intermediate layer forming mixture, a thermal spray material including a metal oxide and a resin or a resin precursor may be produced, and the thermal spray material may be sprayed to form an intermediate layer.

Next, a metal oxide such as yttrium oxide, yttrium aluminum garnet, samarium oxide, dysprosium oxide, etc. similar to the metal oxide used for the intermediate layer 12 is sprayed on the intermediate layer 12 to form a sprayed film 13. To do.
As the thermal spraying method, for example, an ordinary metal oxide thermal spraying method such as atmospheric plasma spraying or reduced pressure argon plasma spraying is used.
As described above, the electrostatic chuck portion 2 can be manufactured.

On the other hand, a thick metal plate is formed by machining a metal material with good thermal conductivity such as aluminum (Al), aluminum alloy, copper (Cu), copper alloy, stainless steel (SUS), etc. A flow path 31 for circulating a cooling medium such as water or an organic solvent is formed, and a fixing hole for fitting and holding the power supply terminal 25 and the insulator 26 is formed as the cooling base portion 3.
It is preferable that at least the surface of the cooling base 3 exposed to plasma is subjected to anodizing or an insulating film such as alumina is formed.

Next, a sheet-like or film-like adhesive resin having plasma resistance, heat resistance and insulation, such as an acrylic resin, a silicon resin, or an epoxy resin, is pasted on a predetermined position on the upper surface of the cooling base portion 3. The adhesive layer 4 is attached.
Next, the electrostatic chuck portion 2 is overlaid on the adhesive layer 4. At this time, the power supply terminal 25 and the insulator 26 which are erected are inserted and fitted into a fixed hole drilled in the cooling base portion 3.
Next, the electrostatic chuck portion 2 is pressed toward the cooling base portion 3, and the electrostatic chuck portion 2 is bonded and integrated with the cooling base portion 3 via the adhesive layer 4.

  As described above, the electrostatic chuck device 1 according to this embodiment in which the electrostatic chuck portion 2 in which the intermediate layer 12 and the sprayed film 13 are sequentially formed on the ceramic base 11 and the cooling base portion 3 are bonded and integrated by the adhesive layer 4. Is obtained.

  As described above, according to the electrostatic chuck device 1 of the present embodiment, the sprayed film 13 is formed on the upper surface 11a of the ceramic substrate 11 via the intermediate layer 12, and the upper surface 13a of the sprayed film 13 is formed into a plate shape. Since it was set as the mounting surface which mounts the sample W, and the intermediate | middle layer 12 consisted of the mixture containing a metal oxide and resin, this intermediate | middle layer 12 contact | adhered between the ceramic base material 11 and the sprayed film 13 It is not necessary to roughen the upper surface 11a of the ceramic substrate 11. Therefore, peeling of the sprayed film 13 from the ceramic base material 11 can be prevented over a long period of time, and changes in the surface shape such as damage to the ceramic base material 11 over time can be prevented.

[Second Embodiment]
FIG. 2 is a cross-sectional view showing an electrostatic chuck device according to a second embodiment of the present invention. The electrostatic chuck device 41 is different from the electrostatic chuck device 1 according to the first embodiment in that In the apparatus 1, the electrostatic chuck part 2 and the cooling base part 3 are bonded and integrated by the adhesive layer 4, whereas in the electrostatic chuck apparatus 41 of this embodiment, the electrostatic chuck part 2, the cooling base part 3, A heater element (heating member) 42 is formed between the two, and the heater element 42 is bonded and integrated to the electrostatic chuck portion 2 and the cooling base portion 3 by adhesive layers 43 and 44. Other configurations The elements are exactly the same as those of the electrostatic chuck device 1 of the first embodiment.

The heater element 42 has a constant thickness of 0.2 mm or less, preferably 0.1 mm or less, such as a non-magnetic metal thin plate, such as a titanium (Ti) thin plate, a tungsten (W) thin plate, a molybdenum (Mo) thin plate, or the like. Is formed by etching into a desired heater pattern by photolithography.
Here, the reason why the thickness of the heater element 42 is 0.2 mm or less is that when the thickness exceeds 0.2 mm, the pattern shape of the heater element 42 is reflected as the temperature distribution of the plate-like sample W. This is because it becomes difficult to maintain the in-plane temperature in a desired temperature pattern, and further, the interval between the electrostatic chuck portion 2 and the cooling base portion 3 is widened, so that the cooling performance is lowered.

If the heater element 42 is formed of a nonmagnetic metal, the heater element 42 does not self-heat due to the high frequency even when the electrostatic chuck device 41 is used in a high frequency atmosphere. This is preferable because it is easy to maintain a constant temperature or a constant temperature pattern.
Further, if the heater element 42 is formed using a non-magnetic metal thin plate having a constant thickness, the thickness of the heater element 42 is constant over the entire heating surface, and the amount of heat generation is also constant over the entire heating surface. The temperature distribution on the surface (mounting surface) of the sprayed film 13 of the part 2 can be made uniform.

The heater element 42 has a predetermined pattern, for example, a pattern in which a narrow band-shaped metal material is meandered, or a pattern in which the metal material is spirally formed. It is adhered by an adhesive layer 43 having the same shape pattern.
The heater element 42 is bonded and integrated on the upper surface of the cooling base portion 3 by a flexible insulating acrylic adhesive layer 44 together with a spacer 45 that keeps the distance from the cooling base portion 3 constant. Yes. Thereby, the electrostatic chuck part 2 and the heater element 42 and the cooling base part 3 are bonded and integrated in a state of being opposed to each other.

Power supply terminals 51 are connected to both ends of the heater element 42, and the power supply terminals 51 and the insulator 52 are fixed to through holes 33 formed in the cooling base portion 3.
In this heater element 42, by controlling the applied voltage, the in-plane temperature distribution of the plate-like sample W fixed to the surface (mounting surface) of the sprayed film 13 of the electrostatic chuck portion 2 by electrostatic adsorption is accurately determined. It comes to control well.

The adhesive layer 43 only needs to be able to adhere the heater element 42 to the lower surface of the electrostatic chuck portion 2, and has the same pattern shape as the heater element 42 in the form of a sheet or film having heat resistance and insulation. Examples thereof include an adhesive having a polyimide adhesive, a silicon adhesive, an epoxy adhesive, an acrylic adhesive, and the like.
In particular, an acrylic adhesive is preferable in consideration of application to an etching apparatus for etching a polycrystalline silicon (polysilicon) thin film.

The thickness of the adhesive layer 43 is preferably 10 μm to 100 μm, more preferably 20 μm to 50 μm. The in-plane thickness variation of the adhesive layer 43 is preferably within 10 μm, more preferably within 5 μm.
Here, if the in-plane thickness variation of the adhesive layer 43 exceeds 10 μm, the in-plane distance between the electrostatic chuck portion 2 and the heater element 42 exceeds 15 μm. The in-plane uniformity of the heat transmitted to the electric chuck portion 2 is reduced, and the in-plane temperature at the surface (mounting surface) of the sprayed film 13 of the electrostatic chuck portion 2 becomes non-uniform. This is not preferable because the uniformity of the in-plane temperature is reduced.

The adhesive layer 44 is a sheet-like or film-like adhesive having heat resistance and insulation like the adhesive layer 43. Examples of the adhesive include an acrylic adhesive, a polyimide adhesive, and silicon. System adhesives, epoxy adhesives, and the like.
In particular, an acrylic adhesive is preferable in consideration of application to an etching apparatus for etching a polycrystalline silicon (polysilicon) thin film.

The thickness of the adhesive layer 44 is preferably 200 μm or less, more preferably 100 μm or less. The in-plane thickness variation of the adhesive layer 44 is preferably within 15 μm.
Here, when the variation in the thickness of the adhesive layer 44 exceeds 15 μm, the change in the thickness due to the curing shrinkage of the adhesive becomes too large, and voids resulting from the curing shrinkage are generated in the obtained adhesive layer 44. Moreover, there is a possibility that cracks and cracks may occur, and as a result, the insulating property of the adhesive layer 44 may be lowered.

Also in the electrostatic chuck device 41 of the present embodiment, the same operations and effects as the electrostatic chuck device 1 of the first embodiment can be achieved.
Further, a heater element 42 is formed between the electrostatic chuck portion 2 and the cooling base portion 3, and the heater element 42 is bonded and integrated to the electrostatic chuck portion 2 and the cooling base portion 3 with adhesive layers 43 and 44. Therefore, the in-plane uniformity of the temperature of the plate-like sample W placed on the placement surface of the sprayed film 13 can be improved, and the in-plane uniformity of the plate-like sample W such as plasma etching or plasma CVD can be improved. Can be improved.

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

[Example 1]
"Production of electrostatic chuck device"
A ceramic substrate was produced by a known method.
The placing plate and the supporting plate of the ceramic base material were aluminum oxide-silicon carbide composite sintered bodies, and had a disk shape with a diameter of 320 mm and a thickness of 6 mm.
These mounting plate and support plate are joined and integrated via an electrostatic adsorption internal electrode and an insulating material layer having a thickness of 20 μm, and then machined to obtain a disk-shaped ceramic substrate having a diameter of 298 mm and a thickness of 4 mm. A material was prepared.

Then, 40% by volume silicone resin, as yttrium oxide (Y 2 _{O 3)} is 60% by volume, it was mixed to prepare an intermediate layer forming mixture.
Then, on the upper surface of the ceramic substrate, the intermediate layer forming mixture was sprayed to a thickness of 0.02 mm to 0.05 mm using a compressed air driving gun, and then heated in air at 150 ° C. for 120 minutes, An intermediate layer was formed.
Next, yttrium oxide (Y ₂ O ₃ ) was sprayed on the upper surface of the intermediate layer by atmospheric plasma spraying so that the total thickness of the intermediate layer and the sprayed film was 0.05 mm to 0.2 mm.

On the other hand, an aluminum cooling base portion 3 having a diameter of 340 mm and a height of 30 mm was produced by machining by a known method. A flow path 31 for circulating the refrigerant is formed in the cooling base portion 3.
Next, the electrostatic chuck portion 2 and the cooling base portion 3 were bonded and integrated using a sheet-like silicon adhesive having a thickness of 0.1 mm, and the electrostatic chuck device of Example 1 was manufactured.

"Evaluation of electrostatic chuck device"
A. Thermal cycle test The operation of alternately blowing hot air of 100 ° C. and cold air of 20 ° C. was defined as one cycle, this cycle was repeated, and the presence or absence of peeling of the sprayed film after a total of 1000 cycles was visually observed. As a result, the sprayed film was not peeled off and the surface condition was good.
B. Withstand voltage test A DC voltage of 10 kV was applied between the sprayed film and the power supply terminal 25 for 120 seconds, and the presence or absence of discharge during application and the presence or absence of peeling of the sprayed film after application were visually observed. As a result, no discharge was observed during application, no peeling of the sprayed film was observed, and the surface condition was good.

[Example 2]
The electrostatic chuck device of Example 2 was prepared according to Example 1 except that the mixture for forming the intermediate layer was prepared so that the silicon resin was 5% by volume and yttrium oxide (Y ₂ O ₃ ) was 95% by volume. The evaluation was made according to Example 1.
As a result, in the thermal cycle test, the sprayed film was not peeled off and the surface condition was good.
In the withstand voltage test, no discharge was observed during application, no peeling of the sprayed film was observed, and the surface condition was good.

[Example 3]
The electrostatic chuck device of Example 3 was prepared in accordance with Example 1 except that the intermediate layer forming mixture was prepared so that the silicon resin was 50% by volume and yttrium oxide (Y ₂ O ₃ ) was 50% by volume. The evaluation was made according to Example 1.
As a result, in the thermal cycle test, the sprayed film was not peeled off and the surface condition was good.
In the withstand voltage test, no discharge was observed during application, no peeling of the sprayed film was observed, and the surface condition was good.

[Example 4]
The electrostatic chuck device of Example 4 was prepared according to Example 1 except that the mixture for forming the intermediate layer was prepared so that the acrylic resin was 40% by volume and yttrium oxide (Y ₂ O ₃ ) was 60% by volume. The evaluation was made according to Example 1.
As a result, in the thermal cycle test, the sprayed film was not peeled off and the surface condition was good.
In the withstand voltage test, no discharge was observed during application, no peeling of the sprayed film was observed, and the surface condition was good.

[Example 5]
The electrostatic chuck device of Example 5 was prepared according to Example 1, except that the mixture for forming the intermediate layer was prepared so that the polyimide resin was 40% by volume and yttrium oxide (Y ₂ O ₃ ) was 60% by volume. The evaluation was made according to Example 1.
As a result, in the thermal cycle test, the sprayed film was not peeled off and the surface condition was good.
In the withstand voltage test, no discharge was observed during application, no peeling of the sprayed film was observed, and the surface condition was good.

[Comparative Example 1]
The electrostatic chuck device of Comparative Example 1 was prepared according to Example 1, except that the intermediate layer forming mixture was prepared so that the silicon resin was 60% by volume and yttrium oxide (Y ₂ O ₃ ) was 40% by volume. The evaluation was made according to Example 1.
As a result, in the thermal cycle test, the sprayed film was not peeled off and the surface condition was good, but in the withstand voltage test, discharge was observed during application, and the sprayed film was also peeled off.

[Comparative Example 2]
An electrostatic chuck device of Comparative Example 2 was prepared according to Example 1, except that the intermediate layer forming mixture was prepared so that the silicon resin was 2% by volume and yttrium oxide (Y ₂ O ₃ ) was 98% by volume. The evaluation was made according to Example 1.
As a result, in the thermal cycle test, the sprayed film was peeled off, and in the withstand voltage test, discharge was observed during application, and the sprayed film was also peeled off.

[Comparative Example 3]
Except that the yttrium oxide (Y ₂ O ₃ ) was sprayed directly to the upper surface of the ceramic substrate by atmospheric plasma spraying to a thickness of 0.2 mm to 0.3 mm to form a sprayed film, in accordance with Example 1. An electrostatic chuck device of Comparative Example 3 was produced and evaluated according to Example 1.
As a result, the thermal sprayed film was peeled off in the thermal cycle test. In the withstand voltage test, discharge was observed when a 6 kV DC voltage was applied between the sprayed film and the cooling base for 120 seconds, and the sprayed film was peeled off.

  In the electrostatic chuck device of the present invention, a thermal spray film 13 made of a metal oxide is formed on an upper surface 11a of a ceramic substrate 11 via an intermediate layer 12, and a plate-like sample W is placed on the upper surface 13a of the thermal spray film 13. The intermediate layer 13 is made of a mixture containing a metal oxide and a resin, and this intermediate layer 12 improves the adhesion between the ceramic substrate 11 and the sprayed film 13. Therefore, peeling of the sprayed film 13 from the ceramic substrate 11 can be prevented over a long period of time, and changes in the surface shape such as damage to the ceramic substrate 11 over time can be prevented. Therefore, not only in the field of semiconductor manufacturing processes such as plasma etching and plasma CVD, but also in fields where corrosion resistance and long-term stability other than plasma are required. Its usefulness is very large.

DESCRIPTION OF SYMBOLS 1 Electrostatic chuck apparatus 2 Electrostatic chuck part 3 Cooling base part 4 Adhesive material layer 11 Ceramic base material 11a Upper surface (one main surface)
12 Intermediate layer 12a Upper surface (one main surface)
13 Thermal sprayed film 13a Upper surface (one main surface)
23 Electrostatic chuck internal electrode 41 Electrostatic chuck device 42 Heater element (heating member)
W Plate specimen

Claims (5)

An internal electrode for electrostatic adsorption is built in the ceramic base material, and a sprayed film made of a metal oxide is formed on one main surface of the ceramic base material via an intermediate layer. An electrostatic chuck portion as a mounting surface for mounting
A cooling base portion provided on the other main surface of the electrostatic chuck portion for cooling the electrostatic chuck portion,
The intermediate layer is made of a mixture of the metal oxide and resin,
The said intermediate | middle layer contains the said metal oxide 50 volume% or more and 95 volume% or less, and contains the said resin 5 volume% or more and 50 volume% or less, The electrostatic chuck apparatus characterized by the above-mentioned.   The electrostatic chuck apparatus according to claim 1, wherein the metal oxide is yttrium oxide.   3. The electrostatic chuck device according to claim 1, wherein the resin includes one or more selected from the group of a silicon-based resin, an acrylic resin, and a polyimide-based resin. The ceramic substrate is an aluminum oxide with the electrostatic chucking device according to any one of claims 1, characterized in that a composite sintered body containing silicon carbide 3. Electrostatic chucking device according to any one of claims 1, characterized by comprising providing a heating element 4 between the cooling base and the electrostatic chuck portion.

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