JP2012142413A - Electrostatic chuck device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic chuck device which suppresses damage to a plate like sample such as a silicon wafer during ion implantation, uniformly makes the plate sample amorphous without causing damage, and prevents moisture condensation even when a back surface is exposed to the atmosphere.SOLUTION: An electrostatic chuck device includes: an electrostatic chuck part 2 having a surface serving as a placement surface 11a on which a plate like sample W is placed and incorporating an internal electrode 13 for electrostatic attraction; and a temperature adjustment base part 3 adjusting the electrostatic chuck part 2 to a desired temperature. A temperature adjustment base material 4 is provided between the electrostatic chuck part 2 and the temperature adjustment base part 3. A recessed part 31 is formed on the electrostatic chuck part 2 side of the temperature adjustment base material 4, and grooves 32 in which a cooling medium flows are formed in the recessed part 31.

Description

  The present invention relates to an electrostatic chuck device, and more specifically, a semiconductor manufacturing process technique in which a plate-like sample such as a semiconductor wafer is adsorbed and fixed by electrostatic force, in particular, ions are implanted into a plate-like sample such as a single crystal silicon wafer. The present invention relates to an electrostatic chuck device suitable for use in an ion implantation process.

In recent years, in semiconductor manufacturing process technologies such as LSI and VLSI, an ion implantation method is used as a method for introducing impurities into a single crystal silicon wafer.
Since this ion implantation method can control the impurity concentration and impurity distribution in the silicon wafer, the ion implantation method is mainly used particularly in a semiconductor manufacturing process such as VLSI.
In this ion implantation method, an ion implantation apparatus having a cooling mechanism capable of cooling a silicon wafer at the time of ion implantation is used (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 5-28951

  By the way, in the conventional ion implantation apparatus described above, in order to ion-implant high-energy impurity ions into a single crystal silicon wafer, there is an advantage of doping impurities in the silicon wafer with good control. At this time, the single crystal silicon may be made amorphous (amorphized) and the crystal lattice may be distorted.

  Since this silicon wafer amorphization proceeds non-uniformly, in the semiconductor manufacturing process after ion implantation, even after annealing for activation due to non-uniform amorphization, Damage at the lattice level such as crystal lattice distortion or lattice defects in the silicon wafer occurs, and this damage at the lattice level causes abnormal leakage current (leakage current) in the final product. There was a problem.

On the other hand, as a method of preventing the non-uniform progression of the amorphization of the silicon wafer and suppressing damage at the lattice level during ion implantation, the ion implantation process is performed while the ion implantation apparatus is cooled with liquid nitrogen. There are low temperature ion implantation processes to be performed.
However, this method can surely suppress damage in the silicon wafer during ion implantation, and can activate the implanted ions by making the silicon wafer amorphous evenly without damage. At the same time, the annealing temperature for recrystallization of the silicon wafer can be lowered, but the electrostatic chuck device for fixing the silicon wafer during ion implantation is also cooled by liquid nitrogen. As a result, the back surface of the electrostatic chuck device When this is exposed to the atmosphere, condensation occurs on the back surface, and in order to prevent this condensation, there is a problem in that it is necessary to take a large measure of condensation on the back surface side.

  As described above, although an effective effect can be obtained by performing ion implantation by the low temperature region ion implantation process, an apparatus capable of performing the low temperature region ion implantation process has not yet been proposed.

  The present invention has been made in view of the above circumstances, and in performing a low temperature region ion implantation process, it is possible to suppress damage in a plate sample such as a silicon wafer during ion implantation, and It is an object of the present invention to provide an electrostatic chuck device that can make amorphization of a sample uniformly without damage, and that does not cause condensation even when the back surface is exposed to the atmosphere.

  As a result of intensive studies to solve the above-described problems, the present inventors have found that an electrostatic chuck portion on which a plate-like sample is placed and a temperature adjustment base portion that adjusts the temperature of the electrostatic chuck portion. If a temperature adjusting base material is provided in between, and a flow path for flowing a cooling medium is formed in the temperature adjusting base material, when performing a low temperature region ion implantation process, a silicon wafer at the time of ion implantation, etc. It is possible to suppress the damage in the plate-like sample and to allow the amorphization of the plate-like sample to proceed uniformly without damage, and there is a possibility that condensation occurs even when the back surface is exposed to the atmosphere. The present inventors have found that there is not, and have completed the present invention.

  In other words, the electrostatic chuck device of the present invention has an electrostatic chuck portion in which one main surface is a mounting surface on which a plate-like sample is placed and an internal electrode for electrostatic attraction is built in, and other electrostatic chuck portions. And a temperature adjusting base portion that adjusts the electrostatic chuck portion to a desired temperature, and a temperature adjusting base material between the electrostatic chuck portion and the temperature adjusting base portion. And a flow path for allowing the cooling medium to flow is formed in the temperature adjusting base material.

In this electrostatic chuck device, by providing a temperature adjusting base material in which a flow path for flowing a cooling medium is provided between the electrostatic chuck portion and the temperature adjusting base portion, the electrostatic chuck portion is The temperature adjustment substrate is cooled to the temperature of the cooling medium, and the temperature adjustment base portion is bonded and fixed to the electrostatic chuck portion via the temperature adjustment substrate. It is insulated from the chuck part, and the temperature of the back surface thereof is maintained at about room temperature (25 ° C. to 20 ° C.).
Thereby, even when the electrostatic chuck portion is cooled to the temperature of the cooling medium by the temperature adjusting base material, the temperature of the back surface of the electrostatic chuck device is set to room temperature (25 ° C. to 20 ° C.) by the temperature adjusting base portion. ) Is kept at a temperature of about. Therefore, even when exposed to the atmosphere, there is no risk of condensation on the back surface.

In the electrostatic chuck device of the present invention, the flow path is a groove formed on a main surface of the temperature adjusting base material on the electrostatic chuck portion side.
In this electrostatic chuck device, the flow path through which the cooling medium flows is a groove formed in the main surface of the temperature adjustment base material on the electrostatic chuck portion side, so that the electrostatic chuck portion It is efficiently cooled by the cooling medium that flows in the grooves formed in the main surface of the material.

In the electrostatic chuck device of the present invention, the electrostatic chuck portion and the temperature adjusting base material are bonded and fixed via a low temperature compatible organic adhesive.
In this electrostatic chuck device, the electrostatic chuck portion and the temperature adjustment base material are bonded and fixed via a low temperature compatible organic adhesive, whereby the electrostatic chuck portion is cooled by the temperature adjustment base material. Even when it is cooled to the temperature, the adhesive strength between the electrostatic chuck portion and the temperature adjusting substrate is maintained, and there is no possibility of peeling or the like.

In the electrostatic chuck device of the present invention, the low-temperature-compatible organic adhesive is an epoxy adhesive.
In this electrostatic chuck device, since the low temperature compatible organic adhesive is an epoxy adhesive, even when the electrostatic chuck portion is cooled down to the temperature of the cooling medium by the temperature adjusting base material, Adhesive strength with the temperature adjusting substrate is sufficiently maintained, and there is no peeling or the like.

  In the electrostatic chuck device of the present invention, the electrostatic chuck portion is made of any one or more of an aluminum oxide-silicon carbide composite sintered body, an aluminum oxide sintered body, an aluminum nitride sintered body, and an yttrium oxide sintered body. The temperature adjusting base material is formed of any one of an aluminum oxide sintered body, an aluminum nitride sintered body, and an yttrium oxide sintered body.

  In this electrostatic chuck device, the electrostatic chuck portion is made of one or more of an aluminum oxide-silicon carbide composite sintered body, an aluminum oxide sintered body, an aluminum nitride sintered body, and an yttrium oxide sintered body. The temperature adjustment base material is made of any one of an aluminum oxide sintered body, an aluminum nitride sintered body, and an yttrium oxide sintered body, thereby improving durability in a semiconductor manufacturing process such as ion implantation. In addition, the mechanical strength is also maintained.

According to the electrostatic chuck device of the present invention, since the temperature adjustment base material in which the flow path for flowing the cooling medium is provided between the electrostatic chuck portion and the temperature adjustment base portion, the electrostatic chuck Even when the part is cooled to the temperature of the cooling medium, the temperature adjustment base is thermally insulated from the electrostatic chuck part by the temperature adjustment base material, so that the temperature of the back surface of the temperature adjustment base part is room temperature (25 ° C. to 25 ° C. 20 ° C.).
Therefore, even when the electrostatic chuck portion is cooled to the temperature of the cooling medium by the temperature adjusting base material, the temperature of the back surface of the electrostatic chuck device is set to room temperature (25 ° C. to 20 ° C.) by the temperature adjusting base portion. Even when exposed to the atmosphere, there is no possibility that condensation occurs on the back surface.

  In addition, since the groove formed on the main surface of the temperature adjusting base material on the electrostatic chuck portion side is used as a flow path for flowing the cooling medium, the electrostatic chuck portion is cooled by flowing the cooling medium in the groove. It can be cooled efficiently by the medium.

  In addition, since the electrostatic chuck and the temperature adjustment substrate are bonded and fixed via a low temperature compatible organic adhesive, the electrostatic chuck is cooled to the temperature of the cooling medium by the temperature adjustment substrate. In addition, the adhesive strength between the electrostatic chuck portion and the temperature adjusting substrate can be maintained, and there is no possibility of peeling or the like.

  In addition, since the low temperature compatible organic adhesive is an epoxy adhesive, even when the electrostatic chuck portion is cooled to the temperature of the cooling medium by the temperature adjusting substrate, the electrostatic chuck portion and the temperature adjusting substrate The adhesive strength between the two can be sufficiently maintained, and there is no possibility of peeling.

  Further, the electrostatic chuck portion is one or more of an aluminum oxide-silicon carbide composite sintered body, an aluminum oxide sintered body, an aluminum nitride sintered body, and an yttrium oxide sintered body, Since any one of the aluminum oxide sintered body, the aluminum nitride sintered body, and the yttrium oxide sintered body is used, the durability in the semiconductor manufacturing process such as ion implantation can be improved and the mechanical strength can be maintained. it can.

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 based on drawing.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

[First Embodiment]
FIG. 1 is a cross-sectional view showing an electrostatic chuck device according to a first embodiment of the present invention. The electrostatic chuck device 1 includes a disk-shaped electrostatic chuck portion 2 and an electrostatic chuck portion 2. A disk-shaped temperature adjustment base portion 3 having a thickness to be adjusted to a desired temperature, a temperature adjustment substrate 4 provided between the electrostatic chuck portion 2 and the temperature adjustment base portion 3, and an electrostatic A low temperature compatible organic adhesive layer 5 for bonding and fixing the chuck portion 2 and the temperature adjusting base material 4 and an adhesive layer 6 for bonding and fixing the temperature adjusting base portion 3 and the temperature adjusting base material 4 mainly. It is configured.

The electrostatic chuck unit 2 has a mounting plate 11 whose upper surface is a mounting surface 11a on which a plate-like sample W such as a semiconductor wafer is mounted, and is integrated with the mounting plate 11 to support the mounting plate 11. A supporting plate 12, an internal electrode 13 for electrostatic adsorption provided between the mounting plate 11 and the supporting plate 12, an insulating material layer 14 for insulating the periphery of the internal electrode 13 for electrostatic adsorption, and a supporting plate 12 and a power supply terminal 15 that applies a DC voltage to the electrostatic adsorption internal electrode 13.
A large number of protrusions 16 are formed on the mounting surface of the mounting plate 11, and these protrusions 16 are configured to support the plate-like sample W.

The mounting plate 11 and the support plate 12 have a disk shape with the same shape of the stacked surfaces, and are an aluminum oxide-silicon carbide (Al ₂ O ₃ —SiC) composite sintered body, aluminum oxide (Al _2). It has mechanical strength such as O ₃ ) sintered body, aluminum nitride (AlN) sintered body, yttrium oxide (Y ₂ O ₃ ) sintered body, and durability in semiconductor manufacturing processes such as ion implantation process. It has an insulating ceramic sintered body.
The material of the mounting plate 11 and the support plate 12 is not particularly limited as long as each function can be sufficiently exhibited. For example, the mounting plate 11 is made of aluminum oxide-silicon carbide (Al ₂ O _3). -SiC) A composite sintered body, a combination in which the support plate 12 is an aluminum oxide (Al ₂ O ₃ ) sintered body, and the like are preferable.

The total thickness of the mounting plate 11, the support plate 12, the electrostatic adsorption internal electrode 13 and the insulating material layer 14, that is, the thickness of the electrostatic chuck portion 2 is preferably 1.0 mm or more and 10 mm or less, and 3.0 mm. More preferably, it is 4.0 mm or less.
The reason is that if the thickness of the electrostatic chuck portion 2 is less than 1.0 mm, the mechanical strength of the electrostatic chuck portion 2 cannot be ensured, while the thickness of the electrostatic chuck portion 2 exceeds 10 mm. Further, the heat capacity of the electrostatic chuck portion 2 becomes too large, the thermal responsiveness of the plate-like sample W to be mounted deteriorates, and further, the plate-like sample is increased due to an increase in the lateral heat transfer of the electrostatic chuck portion. This is because it becomes difficult to maintain the in-plane temperature of W in a desired temperature pattern.

  In particular, the thickness of the mounting plate 11 is preferably 1.0 mm or more and 4.0 mm or less. The reason is that if the thickness of the mounting plate 11 is less than 1.0 mm, the risk of discharge is increased by the voltage applied to the internal electrode 13 for electrostatic attraction, while if it exceeds 4.0 mm, the plate-like sample is increased. This is because W cannot be sufficiently adsorbed and fixed.

The internal electrode 13 for electrostatic adsorption is used as an electrode for an electrostatic chuck for generating a charge and fixing the plate-like sample W with an electrostatic adsorption force. Adjust as appropriate.
The internal electrode 13 for electrostatic adsorption is composed of an aluminum oxide-tantalum carbide (Al ₂ O ₃ —Ta ₄ C ₅ ) conductive composite sintered body, an aluminum oxide-tungsten (Al ₂ O ₃ —W) conductive composite sintered body. body, aluminum oxide - silicon carbide _{(Al 2} O 3 -SiC) conductive composite sintered body, an aluminum nitride - tungsten (AlN-W) conductive composite sintered body, an aluminum nitride - tantalum (AlN-Ta) conductive composite With sintered ceramics, conductive ceramics such as yttrium oxide-molybdenum (Y ₂ O ₃ -Mo) conductive composite sintered bodies, or high melting point metals such as tungsten (W), tantalum (Ta), and molybdenum (Mo) Is formed.

The thickness of the internal electrode 13 for electrostatic adsorption is not particularly limited, but is preferably 5 μm or more and 50 μm or less, and particularly preferably 20 μm or more and 40 μm or less. The reason is that if the thickness is less than 5 μm, sufficient conductivity cannot be ensured. On the other hand, if the thickness exceeds 50 μm, the electrostatic adsorption internal electrode 13, the mounting plate 11, and the support plate 12 This is because cracks are likely to occur at the joint interface between the electrostatic attraction internal electrode 13 and the mounting plate 11 and the support plate 12 due to the difference in thermal expansion coefficient between them.
The electrostatic adsorption internal electrode 13 having such a thickness can be easily formed by a film forming method such as a sputtering method or a vapor deposition method, or a coating method such as a screen printing method.

  The insulating material layer 14 surrounds the internal electrode 13 for electrostatic adsorption and protects the internal electrode 13 for electrostatic adsorption from the atmosphere during ion implantation or the like, and a boundary portion between the mounting plate 11 and the support plate 12, In other words, the outer peripheral region other than the internal electrode 13 for electrostatic adsorption is joined and integrated, and the same composition or the main component of the material constituting the mounting plate 11 and the support plate 12 is made of the same insulating material. .

  The power feeding terminal 15 is a rod-shaped one provided to apply a DC voltage to the electrostatic adsorption internal electrode 13. The material of the power feeding terminal 15 is a conductive material having excellent heat resistance. Although not particularly limited, it is preferable that the coefficient of thermal expansion approximates the coefficient of thermal expansion of the electrostatic adsorption internal electrode 13 and the support plate 12, for example, the conductive material constituting the electrostatic adsorption internal electrode 13. Or metal materials such as tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb), and Kovar alloy are preferably used.

The power feeding terminal 15 is insulated from the temperature adjusting base portion 3 and the temperature adjusting base material 4 by an insulator 17 having insulating properties.
The power supply terminal 15 is joined and integrated with the support plate 12, and the mounting plate 11 and the support plate 12 are joined and integrated by the electrostatic adsorption internal electrode 13 and the insulating material layer 14. The chuck part 2 is configured.

The temperature adjusting base portion 3 is for adjusting the electrostatic chuck portion 2 to a desired temperature, and has a thick disk shape.
As this temperature adjustment base part 3, for example, a water-cooled base in which a flow path 21 for circulating water is formed is suitable.
A concave portion 22 for fitting the temperature adjusting base material 4 is formed on the upper surface of the temperature adjusting base portion 3.

  The material constituting the temperature adjusting base 3 is not particularly limited as long as it is a metal excellent in thermal conductivity, conductivity, and workability, or a composite material containing these metals. For example, aluminum (Al) Aluminum alloy, copper (Cu), copper alloy, stainless steel (SUS) and the like are preferably used. It is preferable that at least the surface of the temperature adjusting base portion 3 exposed to the atmosphere during ion implantation or the like is subjected to an alumite treatment or an insulating film such as alumina is formed.

The temperature adjusting base material 4 is for cooling the electrostatic chuck portion 2 to a desired temperature using a cooling medium such as liquid nitrogen, and is a disk-shaped member having a diameter larger than that of the electrostatic chuck portion 2. (Al ₂ O ₃ ) sintered body, aluminum nitride (AlN) sintered body, yttrium oxide (Y ₂ O ₃ ) sintered body, etc. have mechanical strength and in semiconductor manufacturing processes such as ion implantation process It is made of an insulating ceramic sintered body having durability.

A concave portion 31 for fitting the electrostatic chuck portion 2 is formed on the upper surface (main surface) of the temperature adjusting substrate 4, and a groove 32 for flowing a cooling medium such as liquid nitrogen is formed on the bottom surface of the concave portion 31. Is formed.
The pattern shape of the groove 32 is not particularly limited as long as the electrostatic chuck unit 2 can be cooled to a desired temperature using a cooling medium such as liquid nitrogen, but the lower surface of the electrostatic chuck unit 2 is made uniform. A spiral shape or a meandering shape is preferable in that it can be cooled.

The thickness of the temperature adjusting substrate 4 is preferably 5 mm or more and 30 mm or less, and more preferably 10 mm or more and 20 mm or less.
The reason for this is that when the thickness of the temperature adjusting substrate 4 is less than 5 mm, the mechanical strength of the temperature adjusting substrate 4 is reduced and the heat insulation between the electrostatic chuck portion 2 and the temperature adjusting base portion 3 is performed. As a result, the controllability of the temperature in the electrostatic chuck portion 2 is lowered, and it becomes difficult to maintain the in-plane temperature of the plate-like sample W in a desired temperature pattern.

  On the other hand, when the thickness of the temperature adjusting substrate 4 exceeds 30 mm, heat transfer between the electrostatic chuck portion 2 and the temperature adjusting base portion 3 is ensured, although the mechanical strength of the temperature adjusting substrate 4 is ensured. As a result, the controllability of the temperature in the electrostatic chuck portion 2 is lowered, and it becomes difficult to maintain the in-plane temperature of the plate-like sample W in a desired temperature pattern.

  The low-temperature-compatible organic adhesive layer 5 has an insulating property for bonding and fixing the electrostatic chuck portion 2 cooled by using a cooling medium such as liquid nitrogen and the temperature adjusting substrate 4, and has a heat resistant temperature. It is made of an adhesive having a temperature of −270 ° C. or higher and 120 ° C. or lower. As a material for the low temperature compatible organic adhesive layer 5, an epoxy adhesive having heat resistance in the above temperature range is preferably used.

The thickness of the low-temperature-compatible organic adhesive layer 5 is preferably 50 μm or more and 300 μm or less, more preferably 75 μm, considering the rapidity of heat transfer between the electrostatic chuck portion 2 and the temperature adjusting substrate 4. Above and below 125 μm.
The in-plane thickness variation of the low temperature compatible organic adhesive layer 5 is preferably within 10 μm.
Here, if the in-plane thickness variation of the low-temperature-compatible organic adhesive layer 5 exceeds 10 μm, the in-plane spacing between the electrostatic chuck portion 2 and the temperature adjustment substrate 4 exceeds 10 μm. As a result, the in-plane uniformity of the cold transmitted from the temperature adjusting substrate 4 to the electrostatic chuck unit 2 is reduced, and the in-plane temperature on the mounting surface of the electrostatic chuck unit 2 becomes non-uniform. .

The adhesive layer 6 has an insulating property for bonding and fixing the temperature adjusting substrate 4 and the temperature adjusting base portion 3, and is made of an adhesive having a heat resistant temperature of −100 ° C. or higher and 120 ° C. or lower. .
As the material of the adhesive layer 6, a silicone adhesive, a polyimide adhesive, an epoxy adhesive, etc. having heat resistance in the above temperature range are preferable, and among them, a siloxane bond (Si—O—Si) is used. A silicone-based adhesive having a heat resistant temperature of −50 ° C. or higher and 100 ° C. or lower is preferable.

  This silicone-based adhesive is an adhesive excellent in heat resistance and elasticity, and can be represented by, for example, a chemical formula of the following formula (1) or formula (2).

但し、Ｒは、Ｈまたはアルキル基（Ｃ_ｎＨ_２ｎ＋１−：ｎは整数）である。

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

但し、Ｒは、Ｈまたはアルキル基（Ｃ_ｎＨ_２ｎ＋１−：ｎは整数）である。

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

  As such a silicone-based adhesive, an adhesive having a Young's modulus after curing of 8 MPa or less is preferable. Here, when the Young's modulus after curing exceeds 8 MPa, the thermal expansion of the temperature adjusting base material 4 and the temperature adjusting base portion 3 occurs when the adhesive layer 6 is subjected to a heat cycle of increasing and decreasing temperatures. Since the difference cannot be absorbed and the durability of the adhesive layer 6 is lowered, it is not preferable.

  The thickness of the adhesive layer 6 is preferably not less than 50 μm and not more than 300 μm, more preferably not less than 100 μm and not more than 200 μm, considering heat insulation and stress relaxation between the temperature adjusting base portion 3 and the temperature adjusting base material 4. It is.

Next, a method for manufacturing the electrostatic chuck device 1 will be described.
First, aluminum oxide-silicon carbide (Al ₂ O ₃ —SiC) composite sintered body, aluminum oxide (Al ₂ O ₃ ) sintered body, aluminum nitride (AlN) sintered body, or yttrium oxide (Y ₂ O ₃ ) Using the sintered body, the mounting plate 11 and the support plate 12 having a desired shape are produced. In this case, a mixed powder containing silicon carbide powder and aluminum oxide powder, aluminum oxide powder, aluminum nitride powder, or yttrium oxide powder is formed into a desired shape, and then in a preferable atmosphere for the powder, For example, the mounting plate 11 and the support plate 12 can be obtained by baking at a temperature of 1400 ° C. to 2000 ° C. for a predetermined time.
Next, a plurality of fixing holes for fitting and holding the power feeding terminal 15 and the insulator 17 are formed in the support plate 12. The fixing hole may be formed when the powder is molded.

Next, a coating liquid for forming an internal electrode for electrostatic adsorption in which a conductive material such as the above conductive ceramic powder is dispersed in an organic solvent is prepared, and the coating liquid for forming an internal electrode for electrostatic adsorption is applied to the mounting plate 11. It is applied to a predetermined area on the back surface and dried to form an electrostatic adsorption internal electrode forming layer.
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. Further, as a method other than the above-described coating method, there is a method in which a thin plate made of the above-described conductive ceramics is disposed to form an internal electrode forming layer for electrostatic adsorption.

  In addition, when a high melting point metal such as tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb), or Kovar alloy is used for the internal electrode forming layer for electrostatic adsorption, a vapor deposition method or a sputtering method is used. There are a method of forming a thin film of a refractory metal by a method, a method of disposing a thin plate made of a refractory metal and forming an internal electrode forming layer for electrostatic adsorption.

  In addition, an insulating material is formed on the mounting plate 11 other than the region where the internal electrode forming layer for electrostatic attraction is formed, including a powder material having the same composition or the same main component as the mounting plate 11 and the support plate 12. Form a layer. For example, the insulating material forming layer is formed by applying a coating liquid in which a powder made of an insulating material having the same composition or the same main component as the mounting plate 11 and the support plate 12 is dispersed in an organic solvent by screen printing or the like in the predetermined area. It can be formed by applying and drying.

Next, the support plate 12 is overlaid on the electrostatic adsorption internal electrode forming layer and the insulating material forming layer on the mounting plate 11, and then these are hot-pressed under high temperature and high pressure to be integrated. The atmosphere in this hot press is preferably a vacuum or an inert atmosphere such as Ar, He, N ₂ or the like. Moreover, the pressure in the case of uniaxial pressurization in a hot press is preferably 5 to 10 MPa, and the temperature is preferably 1400 ° C to 1850 ° C.

By this hot pressing, the internal electrode forming layer for electrostatic adsorption is fired to become the internal electrode 13 for electrostatic adsorption made of a conductive composite sintered body. At the same time, the insulating material forming layer is also baked to form the insulating material layer 14, and the support plate 12 and the mounting plate 11 are joined and integrated by the insulating material layer 14.
Then, the upper and lower surfaces, outer periphery, gas holes (not shown) and the like of these joined bodies are machined to form the electrostatic chuck portion 2. This gas hole is a hole formed in the electrostatic chuck portion 2 so that a cooling gas such as helium described later flows between the mounting plate 11 and the plate-like sample W.

On the other hand, the power supply terminal 15 is manufactured so as to have a size and a shape that can be tightly fixed to the fixing hole of the support plate 12. As a method for producing the power supply terminal 15, for example, when the power supply terminal 15 is made of a conductive composite sintered body, a method of forming a conductive ceramic powder into a desired shape and pressurizing and firing can be cited. .
At this time, the conductive ceramic powder used for the power feeding terminal 15 is preferably a conductive ceramic powder made of the same material as the internal electrode 13 for electrostatic adsorption.
In addition, when the power supply terminal 15 is made of metal, a method of using a refractory metal and a metal working method such as a grinding method or powder metallurgy, or the like can be used.

On the other hand, a metal material made of aluminum (Al), aluminum alloy, copper (Cu), copper alloy, stainless steel (SUS), etc. is machined, and water is circulated inside the metal material as necessary. A path or the like is formed, and further, a fixing hole for fitting and holding the power supply terminal 15 and the insulator 17 is formed, and the temperature adjusting base portion 3 is formed.
It is preferable to perform alumite treatment or form an insulating film such as alumina on at least the surface of the temperature adjusting base portion 3 exposed to the atmosphere during ion implantation.
Next, a plurality of fixing holes for fitting and holding the power supply terminal 15 and the insulator 17 are formed in the temperature adjusting base portion 3.

Furthermore, using the aluminum oxide (Al ₂ O ₃ ) sintered body, the aluminum nitride (AlN) sintered body, or the yttrium oxide (Y ₂ O ₃ ) sintered body, the temperature adjusting substrate 4 having a desired shape is formed. Make it. In this case, an aluminum oxide (Al ₂ O ₃ ) powder, an aluminum nitride powder, or an yttrium oxide powder is formed into a desired shape, and then, in an atmosphere preferable for the powder, for example, at a temperature of 1400 ° C. to 2000 ° C. The substrate is baked for a predetermined time to obtain a temperature adjusting substrate 4.
Next, a plurality of fixing holes for fitting and holding the power supply terminals 15 and the insulators 17 are formed in the temperature adjusting substrate 4. The fixing hole may be formed when the powder is molded.

  Next, the lower surface of the support plate 12 of the electrostatic chuck unit 2, that is, the surface to which the temperature adjustment base material 4 is bonded is degreased and washed using, for example, acetone. Using an application method, an epoxy adhesive having a heat resistant temperature of −270 ° C. or higher and 120 ° C. or lower is applied so as to have a thickness of 100 μm or more and 200 μm or less.

  Further, the lower surface of the temperature adjusting substrate 4, that is, the surface to which the temperature adjusting base portion 3 is bonded is degreased and washed using, for example, acetone, and a coating method such as a screen printing method is applied to a predetermined region on this surface. A silicone adhesive, polyimide adhesive, or epoxy adhesive having a heat resistant temperature of −100 ° C. or higher and 120 ° C. or lower is applied so as to have a thickness of 200 μm or more and 300 μm or less.

  Next, the electrostatic chuck portion 2, the temperature adjustment base material 4, and the temperature adjustment base portion 3 are overlapped in this order. At this time, the power supply terminal 15 and the insulator 17 are inserted and fitted into a power supply terminal accommodation hole (not shown) drilled in the temperature adjustment base 3 and the temperature adjustment base material 4.

  Next, the electrostatic chuck part 2, the temperature adjusting base material 4, the temperature adjusting base part 3, the power feeding terminal 15 and the insulator 17 are pressurized and held at 80 ° C. or higher and 100 ° C. or lower in the atmosphere. Are bonded and integrated. By this pressurization and holding, the epoxy adhesive applied to the lower surface of the support plate 12 is cured to become a low temperature compatible organic adhesive layer 5, and a silicone adhesive applied to the lower surface of the temperature adjusting substrate 4, The polyimide adhesive or the epoxy adhesive is cured to form the adhesive layer 6.

  As described above, the electrostatic chuck portion 2, the temperature adjustment base material 4, the temperature adjustment base portion 3, the power feeding terminal 15 and the insulator 17 are joined and integrated through the low temperature compatible organic adhesive layer 5 and the adhesive layer 6. Thus, the electrostatic chuck device 1 of this embodiment is obtained.

According to the electrostatic chuck device 1, a temperature adjusting groove in which a groove 32 for allowing a cooling medium to flow is formed in the concave portion 31 on the electrostatic chuck portion 2 side between the electrostatic chuck portion 2 and the temperature adjusting base portion 3. Since the substrate 4 is provided, the temperature adjustment base 3 can be insulated from the electrostatic chuck 2 by the temperature adjustment substrate 4 even when the electrostatic chuck 2 is cooled to the temperature of the cooling medium. The temperature of the lower surface of the temperature adjusting base 3 can be maintained at about room temperature (25 ° C. to 20 ° C.).
Therefore, even when the electrostatic chuck portion 2 is cooled to the temperature of the cooling medium by the temperature adjustment base material 4, the temperature of the back surface of the electrostatic chuck device 1 is changed to the room temperature (25 ° C.) by the temperature adjustment base portion 3. It can be kept at a temperature of about 20 ° C.), and even when exposed to the atmosphere, there is no risk of condensation on the back surface.

  In addition, since the electrostatic chuck portion 2 and the temperature adjustment base material 4 are bonded and fixed via the low temperature compatible organic adhesive layer 5, the electrostatic chuck portion 2 is attached to the cooling medium by the temperature adjustment base material 4. Even when cooled to the temperature, the adhesive strength between the electrostatic chuck portion 2 and the temperature adjusting substrate 4 can be maintained, and there is no possibility of peeling or the like.

[Second Embodiment]
FIG. 2 is a 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 electrostatic chuck device 1 according to the embodiment, a concave portion 31 for fitting the electrostatic chuck portion 2 is formed on the upper surface of the temperature adjusting base material 4, and a cooling medium such as liquid nitrogen flows on the bottom surface of the concave portion 31. Whereas the groove 32 to be formed is formed, in the electrostatic chuck device 41 of the present embodiment, the liquid is disposed inside the temperature adjustment base material 42 in which the concave portion 31 for fitting the electrostatic chuck portion 2 is formed on the upper surface. This is that a flow path 43 for flowing a cooling medium such as nitrogen is formed, and the other points are the same as those of the electrostatic chuck device 1 of the first embodiment.

  The pattern shape of the flow path 43 is not particularly limited as long as the electrostatic chuck unit 2 can be cooled to a desired temperature using a cooling medium such as liquid nitrogen, but the lower surface of the electrostatic chuck unit 2 is uniform. From the viewpoint of being able to be cooled to a low temperature, a spiral shape or a meandering shape is preferable.

This electrostatic chuck device 41 can also provide the same operations and effects as the electrostatic chuck device 1 of the first embodiment.
In addition, since the flow path 43 for flowing a cooling medium such as liquid nitrogen is formed inside the temperature adjusting base material 42 in which the recess 31 for fitting the electrostatic chuck portion 2 is formed on the upper surface, this flow path is formed. By causing the cooling medium to flow through 43, the electrostatic chuck portion 2 can be efficiently cooled by the cooling medium.

  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)
An electrostatic chuck portion 2 in which an internal electrode 13 for electrostatic attraction having a thickness of 30 μm was embedded was produced by a known method.
The mounting plate 11 of the electrostatic chuck portion 2 is an aluminum oxide-silicon carbide composite sintered body containing 8% by mass of silicon carbide, and has a disk shape with a diameter of 200 mm and a thickness of 2 mm. Further, the electrostatic chucking surface of the mounting plate 11 is formed as an uneven surface by forming a large number of protrusions 16 having a height of 30 μm, and the top surface of these protrusions 16 is used as a holding surface for the plate-like sample W. The cooling gas can be made to flow in a groove formed between the recess and the electrostatically adsorbed plate-like sample W.

Similarly to the mounting plate 11, the support plate 12 is an aluminum oxide-silicon carbide composite sintered body containing 8% by mass of silicon carbide, and has a disk shape with a diameter of 200 mm and a thickness of 2 mm.
By joining and integrating the mounting plate 11 and the support plate 12, the entire thickness of the electrostatic chuck portion 2 was 4 mm.

  On the other hand, an aluminum temperature adjusting base 3 having a diameter of 250 mm and a height of 20 mm was produced by machining. A flow path (not shown) for circulating the refrigerant was formed inside the temperature adjusting base 3.

Further, by using the aluminum oxide (Al 2 _{O 3)} sintered body, to produce a temperature adjustment substrate 4. The temperature adjusting substrate 4 had a disk shape with a diameter of 220 mm and a thickness of 15 mm. Further, a spiral groove 32 having a depth of 25 mm and a width of 12 mm is formed in the concave portion 31 on the upper surface of the temperature adjusting substrate 4 so that a cooling medium such as liquid nitrogen can flow.

Next, the lower surface of the support plate 12 of the electrostatic chuck portion 2 is degreased and washed with acetone, and an epoxy adhesive SK-, which is a low temperature compatible organic adhesive, is applied to a predetermined region of the lower surface by screen printing. 229 (manufactured by Nitto Denko Corporation) was applied to a thickness of 200 μm.
Next, the lower surface of the temperature adjusting substrate 4 is degreased and washed with acetone, and a silicone adhesive TSE3221 (manufactured by Momentive) is made to have a thickness of 300 μm on a predetermined region of the lower surface by screen printing. Applied.

Next, the electrostatic chuck portion 2, the temperature adjustment base material 4 and the temperature adjustment base portion 3 are superposed in this order, and the power supply terminal 15 and the insulator 17 are placed in the temperature adjustment base portion 3 and the temperature adjustment base material 4. And inserted into the power supply terminal accommodating hole perforated.
Next, the electrostatic chuck part 2, the temperature adjusting base material 4, the temperature adjusting base part 3, the power feeding terminal 15 and the insulator 17 are pressurized and held at 25 ° C. in the atmosphere, and these are bonded and integrated. The electrostatic chuck device of Example 1 was manufactured.
As a result, the epoxy adhesive applied to the lower surface of the support plate 12 is cured to form a low temperature compatible organic adhesive layer 5, and the silicone adhesive applied to the lower surface of the temperature adjusting substrate 4 is cured. The adhesive layer 6 was obtained.

(Evaluation)
This electrostatic chuck device was subjected to a thermal cycle test and evaluated for the presence or absence of peeling of the adhesive.
The method of the thermal cycle test is as follows.
While flowing 20 ° C. water through the flow path 21 of the temperature adjusting base 3, −100 ° C. liquid nitrogen is allowed to flow through the groove 32 of the temperature adjusting substrate 4 to cool the electrostatic chuck 2 to −100 ° C. The introduction of liquid nitrogen was stopped when the electrostatic chuck portion 2 reached -100 ° C. Thereafter, the electrostatic chuck unit 2 is allowed to stand until it reaches 20 ° C., and when the electrostatic chuck unit 2 reaches 20 ° C., water of 20 ° C. is allowed to flow again through the flow path 21 of the temperature adjustment base unit 3. Then, liquid nitrogen at −100 ° C. was caused to flow through the groove 32 of the temperature adjusting substrate 4 to cool the electrostatic chuck portion 2 to −100 ° C.
This thermal cycle of “cooling to −100 ° C.” and “standing at 20 ° C.” was repeated a total of 10 times.
At the same time, the presence or absence of condensation on the back surface of the electrostatic chuck device during the thermal cycle was also confirmed.

According to the evaluation result of the thermal cycle test, the following was found.
Although the electrostatic chuck part 2 was cooled to the temperature of liquid nitrogen by the temperature adjustment base material 4, the adhesive strength between the electrostatic chuck part 2 and the temperature adjustment base material 4 was high, and peeling was not recognized.
Also, no condensation was observed on the back surface of the electrostatic chuck device during this thermal cycle.

"Example 2"
(Production of electrostatic chuck device)
Except that the mounting plate 11 and the support plate 12 of the electrostatic chuck part 2 are made of yttrium oxide sintered body and the temperature adjusting base material 4 is also made of yttrium oxide sintered body, An electrostatic chuck device was produced.

(Evaluation)
The electrostatic chuck device of Example 2 was evaluated according to Example 1. As a result, the following was found.
Although the electrostatic chuck part 2 was cooled to the temperature of liquid nitrogen by the temperature adjustment base material 4, the adhesive strength between the electrostatic chuck part 2 and the temperature adjustment base material 4 was high, and peeling was not recognized.
Also, no condensation was observed on the back surface of the electrostatic chuck device during this thermal cycle.

“Comparative Example 1”
(Production of electrostatic chuck device)
The electrostatic chuck part 2 and the temperature adjusting substrate 4 are bonded and fixed in accordance with Example 1 except that an epoxy adhesive having a heat resistant temperature of −50 ° C. is used instead of the low temperature compatible organic adhesive. The electrostatic chuck device of Comparative Example 1 was produced.

(Evaluation)
The electrostatic chuck device of Comparative Example 1 was evaluated according to Example 1. As a result, the following was found.
When the electrostatic chuck part 2 was cooled to the temperature of liquid nitrogen by the temperature adjustment base material 4, the electrostatic chuck part 2 and the temperature adjustment base material 4 were peeled off.
In addition, when exposed to the atmosphere, condensation occurred on the back surface of the electrostatic chuck device.

"Comparative Example 2"
(Production of electrostatic chuck device)
Example 1 except that the electrostatic chuck portion 2 and the temperature adjusting base portion 3 were directly bonded and fixed using an epoxy adhesive SK-229 (manufactured by Nitto Denko Corporation), which is a low temperature compatible organic adhesive. In accordance with the above, an electrostatic chuck device of Comparative Example 2 was produced.

(Evaluation)
When the entire electrostatic chuck device was cooled to −100 ° C. by flowing liquid nitrogen at −100 ° C. through the flow path 21 of the temperature adjustment base portion 3 of the electrostatic chuck device of Comparative Example 2, the electrostatic chuck portion 2 No peeling was observed between the base part 3 and the temperature adjusting base 3.
However, when the ion implantation process was performed using this electrostatic chuck device, dew condensation occurred on the back surface of the electrostatic chuck device.

DESCRIPTION OF SYMBOLS 1 Electrostatic chuck apparatus 2 Electrostatic chuck part 3 Temperature adjustment base part 4 Temperature adjustment base material 5 Low-temperature-compatible organic adhesive layer 6 Adhesive layer 11 Mounting plate 11a Mounting surface 12 Support plate 13 For electrostatic adsorption Internal electrode 14 Insulating material layer 15 Power supply terminal 16 Protrusion 17 Insulator 21 Flow path 22 Recess 31 Recess 32 Groove 41 Electrostatic chuck device 42 Temperature adjusting base material 43 Flow path W Plate-like sample

Claims (5)

One main surface is used as a mounting surface on which a plate-like sample is placed, and an electrostatic chuck portion having a built-in electrostatic adsorption internal electrode, and the electrostatic chuck portion provided on the other main surface side of the electrostatic chuck portion is arranged on the electrostatic surface. A temperature adjusting base portion for adjusting the chuck portion to a desired temperature,
A temperature adjusting base material is provided between the electrostatic chuck portion and the temperature adjusting base portion,
An electrostatic chuck device comprising a flow path for allowing a cooling medium to flow in the temperature adjusting base material.   The electrostatic chuck apparatus according to claim 1, wherein the flow path is a groove formed in a main surface of the temperature adjusting base material on the electrostatic chuck portion side.   The electrostatic chuck apparatus according to claim 1, wherein the electrostatic chuck unit and the temperature adjusting base material are bonded and fixed via a low temperature compatible organic adhesive.   The electrostatic chuck apparatus according to claim 3, wherein the low temperature compatible organic adhesive is an epoxy adhesive.   The electrostatic chuck portion is composed of one or more of an aluminum oxide-silicon carbide composite sintered body, an aluminum oxide sintered body, an aluminum nitride sintered body, and an yttrium oxide sintered body, 5. The electrostatic chuck device according to claim 1, comprising any one of a sintered body of aluminum oxide, a sintered body of aluminum nitride, and a sintered body of yttrium oxide.

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