JP4943085B2 - Electrostatic chuck apparatus and plasma processing apparatus - Google Patents

Description

The present invention relates to an electrostatic chuck apparatus and a plasma processing apparatus , and more specifically, generates a plasma by applying a high frequency to an electrode, and plasma processing is performed on a plate-like sample such as a semiconductor wafer, a metal wafer, or a glass plate by the plasma. The present invention relates to an electrostatic chuck device and a plasma processing apparatus suitable for use in a high-frequency discharge plasma processing apparatus.

  Conventionally, in processing such as etching, deposition, oxidation, sputtering, etc. in a manufacturing process of semiconductor devices such as IC, LSI, VLSI, or flat panel displays (FPD) such as liquid crystal displays, the processing gas is relatively low temperature. In order to make a good reaction, a lot of plasma is used. In general, plasma processing apparatuses are roughly classified into a method using glow discharge or high-frequency discharge and a method using microwaves as a method for generating plasma.

FIG. 11 is a cross-sectional view showing an example of an electrostatic chuck device mounted on a conventional high-frequency discharge type plasma processing apparatus. The electrostatic chuck device 1 is provided at a lower portion of a chamber (not shown) that also serves as a vacuum container. The electrostatic chuck unit 2 is provided and the metal base unit 3 is fixed to and integrated with the bottom surface of the electrostatic chuck unit 2.
The electrostatic chuck unit 2 has an upper surface as a mounting surface 4a on which a plate-like sample W such as a semiconductor wafer is mounted and electrostatically attracts, and a substrate 4 having an internal electrode 5 for electrostatic adsorption, The power supply terminal 6 is configured to apply a DC voltage to the suction internal electrode 5, and the power supply terminal 6 is connected to a high voltage DC power supply 7 that applies a high voltage DC voltage. The metal base portion 3 also serves as a high-frequency generating electrode (lower electrode), and is connected to a high-frequency voltage generating power source 8 and a flow path 9 for circulating a cooling medium such as water or an organic solvent is formed therein. Has been. The chamber is grounded.

In this electrostatic chuck device 1, a plate-like sample W is placed on a placement surface 4 a, and a DC voltage is applied to the internal electrode 5 for electrostatic attraction via a power supply terminal 6 by a high-voltage DC power source 7. The sample W is electrostatically adsorbed. Next, the inside of the chamber is evacuated and a processing gas is introduced, and a high frequency power is applied between the metal base portion 3 (lower electrode) and the upper electrode (not shown) by the high frequency voltage generating power source 8 to generate a high frequency in the chamber. Generate an electric field. As the high frequency, a frequency in the region of 10 or less MHz is generally used.
Electrons are accelerated by the high-frequency electric field, and plasma is generated by impact ionization of the electrons and the processing gas, and various treatments can be performed by the plasma.

  By the way, in recent years, in plasma processing, there is an increasing demand for processing using “low energy high density plasma” in which ion energy in plasma is low and electron density is high. In the processing using this low-energy high-density plasma, the frequency of the high-frequency power for generating the plasma may be very high, for example, 100 MHz, compared to the conventional case. As described above, when the frequency of the applied power is increased, the electric field strength tends to increase in the region corresponding to the center of the electrostatic chuck portion 2, that is, the center of the plate-like sample W, but weak in the peripheral portion. is there. For this reason, if the electric field intensity distribution is non-uniform, the electron density of the generated plasma will also be non-uniform, and the processing speed will vary depending on the position in the plane of the plate-like sample W. There has been a problem in that good processing results cannot be obtained.

In order to solve such a problem, a plasma processing apparatus shown in FIG. 12 has been proposed (Patent Document 1).
In order to improve the in-plane uniformity of the plasma processing, the plasma processing apparatus 11 is made of ceramic or the like at the center of the surface of the lower electrode (metal base portion) 12 to which the high frequency power is applied facing the upper electrode 13. The dielectric layer 14 is embedded to make the electric field strength distribution uniform. In the figure, 15 is a power source for high frequency generation, PZ is plasma, E is electric field strength, and W is a plate sample.
In this plasma processing apparatus 11, when high-frequency power is applied to the lower electrode 12 by the high-frequency generating power supply 15, the high-frequency current that has propagated through the surface of the lower electrode 12 due to the skin effect and reached the upper part is applied to the surface of the plate-like sample W. Along the center, a part leaks to the lower electrode 12 side, and then flows inside the lower electrode 12 outward. In this process, the high-frequency current causes TM-mode cavity cylindrical resonance by being deeper in the portion where the dielectric layer 14 is provided than in the portion where the dielectric layer 14 is not provided. As a result, the electric field strength at the central portion supplied to the plasma from the surface of the plate sample W becomes weak, and the electric field in the surface of the plate sample W becomes uniform.

By the way, the plasma processing is often performed under a reduced pressure close to a vacuum, and in such a case, an electrostatic chuck device as shown in FIG.
This electrostatic chuck device 16 has a structure in which a dielectric internal electrode 18 is incorporated in a dielectric layer 17. For example, the electrostatic chuck device 16 is electrically conductive by two dielectric layers formed by spraying alumina or the like. The internal electrode for electrostatic attraction is sandwiched.
In this electrostatic chuck device 16, the high voltage direct current power source 7 applies high voltage direct current power to the internal electrode 18 for electrostatic adsorption and uses the electrostatic adsorption force generated on the surface of the dielectric layer 17, thereby making the plate-like sample W Is fixed by electrostatic adsorption.
JP 2004-363552 A (paragraphs 0084 to 0085 on page 15, FIG. 19)

By the way, in the above-described conventional plasma processing apparatus 11, when the electrostatic chuck device 16 is installed on the lower electrode 12 to perform the plasma processing of the plate-like sample W, the high frequency current is electrostatically attracted by the electrostatic chuck device 16. The internal electrode 18 cannot be passed, and the outward flow is generated in the electrostatic adsorption internal electrode 18.
In other words, because the electrostatic chucking internal electrode 18 exists in the electrostatic chuck device 16, the dielectric layer 14 becomes invisible from the plasma PZ, and the plasma in the region where the dielectric layer 14 is embedded is removed. The effect for lowering the potential cannot be exhibited. As a result, the plasma potential above the central portion of the plate-like sample W is high and the potential at the peripheral portion is low, and the processing speed differs between the central portion and the peripheral portion of the plate-like sample W. It was a cause of in-plane non-uniformity in plasma processing.

The present invention has been made in view of the above circumstances, and when applied to a plasma processing apparatus, the in-plane uniformity of the electric field strength in the plasma is improved, and the in-plane uniformity with respect to the plate-like sample is improved. It is an object of the present invention to provide an electrostatic chuck device and a plasma processing apparatus capable of performing high plasma processing.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-described problems can be efficiently solved if any one of the following configurations (1) and (2) is adopted. The present invention has been completed.
(1) A concave portion is formed on the main surface of the metal base portion on the electrostatic chuck portion side, a dielectric plate is fixed in the concave portion, and the dielectric plate and the electrostatic chuck portion have a dielectric constant of a dielectric plate. The dielectric plate and the concave portion are bonded and bonded through an insulating adhesive / bonding agent layer smaller than any of the substrate and the substrate, and the dielectric bond is smaller than that of either the dielectric plate or the substrate. -Adhesion and bonding through the bonding agent layer.
(2) A concave portion is formed on the main surface of the metal base portion on the electrostatic chuck portion side, the electrostatic chuck portion is fixed to the concave portion, and the dielectric constant between the electrostatic chuck portion and the concave portion is smaller than that of the substrate. Adhesion and bonding through the adhesive / bonding agent layer.

That is, the electrostatic chuck device according to claim 1 of the present invention has a main surface as a mounting surface on which a plate-like sample is mounted and a substrate having a built-in electrostatic chucking internal electrode, and the electrostatic chucking device. An electrostatic chuck portion having a power feeding terminal for applying a DC voltage to the internal electrode, and a metal base portion fixed to and integrated with the other main surface of the base body of the electrostatic chuck portion to serve as a high frequency generating electrode A concave portion is formed on the main surface of the metal base portion on the electrostatic chuck portion side, and a dielectric plate is fixed in the concave portion, and the dielectric plate and the electrostatic chuck portion have a dielectric constant. Are bonded and bonded via an insulating adhesive / bonding agent layer smaller than either of the dielectric plate and the substrate, and the dielectric plate and the recess have a dielectric constant of the dielectric plate and the substrate. Adhesion / bonding via a smaller insulating adhesive / bonding agent layer Is the volume resistivity of the internal electrode for electrostatic adsorption is equal to or less than 1.0 × ^{10 -1} Ω · cm or more and 1.0 × 10 ⁸ Ω · cm.

  The electrostatic chuck device according to a second aspect of the present invention is the electrostatic chuck device according to the first aspect, wherein the thickness of the dielectric plate is reduced from the central portion toward the peripheral portion. .

  The electrostatic chuck device according to a third aspect of the present invention is the electrostatic chuck device according to the first or second aspect, wherein the clearance between the dielectric plate and the concave portion is a diameter when the dielectric plate is circular. When the dielectric plate is rectangular, it is 0.1% or more of the length of the diagonal line of the rectangle.

  According to a fourth aspect of the present invention, in the electrostatic chuck device according to the first, second, or third aspect, a clearance between the dielectric plate and the recess is 2.0 mm or less. And

  The electrostatic chuck device according to a fifth aspect of the present invention is the electrostatic chuck device according to any one of the first to fourth aspects, wherein the concave portion is complementary to a main surface of the dielectric plate on the concave side. It is characterized by being.

  An electrostatic chuck device according to a sixth aspect of the present invention is the electrostatic chuck device according to any one of the first to fifth aspects, wherein the thermal conductivity between the electrostatic chuck portion and the metal base portion is Further, it is uniform over the entire adsorption region of the electrostatic chuck portion.

According to a seventh aspect of the present invention, there is provided an electrostatic chuck device having a main surface as a placement surface on which a plate-like sample is placed and a substrate having a built-in electrostatic adsorption internal electrode, and the electrostatic adsorption internal electrode. An electrostatic chuck portion having a power supply terminal for applying a DC voltage to the base plate, and a metal base portion fixed to and integrated with the other main surface of the base of the electrostatic chuck portion and serving as a high frequency generating electrode. A concave portion is formed in a main surface of the metal base portion on the electrostatic chuck portion side, and the electrostatic chuck portion is fixed to the concave portion. The electrostatic chuck portion and the concave portion have a dielectric constant of the base body. The volume specific resistance of the internal electrode for electrostatic adsorption is 1.0 × 10 ⁻¹ Ω · cm or more and 1.0 × 10 ⁸ Ω, which are bonded and bonded through a smaller insulating bonding / bonding agent layer. -It is characterized by being cm or less .

  An electrostatic chuck device according to an eighth aspect of the present invention is the electrostatic chuck device according to the seventh aspect, characterized in that the thickness of the substrate is reduced from the central portion toward the peripheral portion.

  The electrostatic chuck device according to claim 9 of the present invention is the electrostatic chuck device according to claim 7 or 8, wherein the clearance between the base and the recess is 0.1% of the diameter when the base is circular. In the case where the base is rectangular, the length is 0.1% or more of the diagonal length of the rectangle.

  An electrostatic chuck device according to a tenth aspect of the present invention is the electrostatic chuck device according to the seventh, eighth or ninth aspect, wherein a clearance between the base and the recess is 2.0 mm or less. .

  An electrostatic chuck device according to an eleventh aspect of the present invention is the electrostatic chuck device according to any one of the seventh to tenth aspects, wherein the concave portion is complementary to the other main surface of the base. Features.

  The electrostatic chuck device according to claim 12 of the present invention is the electrostatic chuck device according to any one of claims 7 to 11, wherein the thermal conductivity between the electrostatic chuck portion and the metal base portion is Further, it is uniform over the entire adsorption region of the electrostatic chuck portion.

  The electrostatic chuck device according to a thirteenth aspect of the present invention is the electrostatic chuck device according to any one of the first to twelfth aspects, wherein the insulating adhesive / bonding agent layer is an aluminum nitride-added silicone adhesive / It consists of a bonding agent.

  The electrostatic chuck device according to a fourteenth aspect of the present invention is the electrostatic chuck device according to any one of the first to thirteenth aspects, wherein the electrostatic chucking internal electrodes are a plurality of concentric circles insulated from each other. It consists of an electrode part, The said terminal for electric power feeding is connected to each of these electrode parts, It is characterized by the above-mentioned.

An electrostatic chuck device according to a fifteenth aspect of the present invention is the electrostatic chuck device according to any one of the first to thirteenth aspects, wherein the electrostatic chucking device has a central portion of the electrostatic chucking internal electrode. An opening having an area of 1/9 or more and 4/9 or less of the total area of the internal electrode is formed, and this opening is filled with an insulating material.
A plasma processing apparatus according to claim 16 of the present invention is characterized in that the electrostatic chuck apparatus according to any one of claims 1 to 15 is mounted in a chamber for performing plasma processing.

  According to the electrostatic chuck device of the first aspect of the present invention, the concave portion is formed in the main surface of the metal base portion on the electrostatic chuck portion side, and the dielectric plate is fixed in the concave portion. The electric chuck portion is bonded / bonded via an insulating adhesive / bonding agent layer having a dielectric constant smaller than that of either the dielectric plate or the substrate, and the dielectric plate and the concave portion are bonded to each other. Since it is bonded and bonded via an insulating adhesive / bonding agent layer smaller than any of the substrates, high-frequency current must pass through the insulating adhesive / bonding agent layer when a high-frequency voltage is applied to the metal base. It is possible to prevent the high-frequency current from flowing in the direction of the outer edge portion through the insulating adhesive / bonding agent layer, and the electric field strength on the surface of the electrostatic chuck portion can be made uniform. Therefore, the plasma density on the surface of the plate-like sample can be flattened, and as a result, uniform plasma treatment can be performed over the entire surface of the plate-like sample.

  In addition, since the dielectric plate and the concave portion are bonded / bonded via an insulating adhesive / bonding agent layer having a dielectric constant smaller than that of either the dielectric plate or the substrate, a high frequency voltage is applied to the metal base portion In addition, the dielectric plate can effectively prevent the current from flowing from the peripheral portion of the surface of the metal base portion toward the center portion due to the skin effect, and the electric field strength on the surface of the electrostatic chuck portion is made uniform. be able to. Therefore, the plasma density on the surface of the plate-like sample can be flattened, and as a result, uniform plasma treatment can be performed over the entire surface of the plate-like sample.

  According to the electrostatic chuck device of claim 2 of the present invention, since the thickness of the dielectric plate is decreased from the central portion toward the peripheral portion, the plasma distribution that is denser toward the central portion can be flattened. And the plasma density on the surface of the plate-like sample can be made more uniform.

  According to the electrostatic chuck device of claim 3 of the present invention, the clearance between the dielectric plate and the concave portion is set to 0.1% or more of the diameter when the dielectric plate is circular, and when the dielectric plate is rectangular. Since the length of the rectangular diagonal line is 0.1% or more, the warp of the metal base due to the difference in the thermal expansion coefficient between the dielectric plate and the metal base, the dielectric plate and electrostatic It can prevent damage to the base of the chuck, peeling of the adhesive / bonding layer between the metal base and the dielectric plate, and peeling of the bonding / bonding layer between the dielectric plate and the electrostatic chuck. it can.

  According to the electrostatic chuck device of claim 4 of the present invention, since the clearance between the dielectric plate and the recess is 2.0 mm or less, the in-plane thermal uniformity of the plate-like sample can be improved, and the plasma treatment Can be made uniform.

  According to the electrostatic chuck device of the fifth aspect of the present invention, since the concave portion has a complementary shape with the main surface of the dielectric plate on the concave portion side, positioning and fixing between the metal base portion and the dielectric plate are performed. Can be made easy and reliable.

  According to the electrostatic chuck device of claim 6 of the present invention, the thermal conductivity between the electrostatic chuck portion and the metal base portion is uniform over the entire adsorption region of the electrostatic chuck portion. The in-plane thermal uniformity of the sample can be improved, and the plasma processing can be made uniform.

According to the electrostatic chuck device of the present invention, the concave portion is formed in the main surface of the metal base portion on the electrostatic chuck portion side, and the electrostatic chuck portion is fixed to the concave portion. Since the concave portion is bonded / bonded via an insulating adhesive / bonding agent layer whose dielectric constant is smaller than that of the base, when a high frequency voltage is applied to the metal base portion, the electrostatic chuck portion causes an electric current due to the skin effect. It is possible to effectively prevent the flow from the peripheral portion of the surface of the metal base portion toward the center portion, and the electric field strength on the surface of the electrostatic chuck portion can be made uniform. Therefore, the plasma density on the surface of the plate-like sample can be flattened, and as a result, uniform plasma treatment can be performed over the entire surface of the plate-like sample.
Further, since the electrostatic chuck portion is fixed to the concave portion of the metal base portion, positioning and fixing between the metal base portion and the electrostatic chuck portion can be easily performed.

  According to the electrostatic chuck device of the eighth aspect of the present invention, since the thickness of the substrate is reduced from the central portion toward the peripheral portion, the plasma distribution that is denser toward the central portion can be flattened. The plasma density on the surface of the plate sample can be made more uniform.

  According to the electrostatic chuck device of the ninth aspect of the present invention, the clearance between the base and the recess is 0.1% or more of the diameter when the base is circular, and the rectangular diagonal line when the base is rectangular. Since the length is 0.1% or more, the base of the electrostatic chuck part is warped due to the difference in thermal expansion coefficient between the base of the electrostatic chuck part and the metal base part, and the base of the electrostatic chuck part is damaged due to this warp. Further, peeling of the adhesive / bonding agent layer between the metal base portion and the base of the electrostatic chuck portion can be prevented.

  According to the electrostatic chuck device of claim 10 of the present invention, since the clearance between the substrate and the recess is 2.0 mm or less, the in-plane heat uniformity of the plate-like sample can be improved, and the plasma processing is uniform. Can be achieved.

  According to the electrostatic chuck device of the eleventh aspect of the present invention, since the concave portion has a shape complementary to the other main surface of the base body, positioning and fixing between the metal base portion and the base body can be easily and reliably performed. be able to.

  According to the electrostatic chuck device of the twelfth aspect of the present invention, since the thermal conductivity between the electrostatic chuck portion and the metal base portion is uniform over the entire adsorption region of the electrostatic chuck portion, The in-plane thermal uniformity of the sample can be improved, and the plasma processing can be made uniform.

  According to the electrostatic chuck device of claim 13 of the present invention, since the insulating adhesive / bonding agent layer is an aluminum nitride-added silicone adhesive / bonding agent, the aluminum nitride-added silicone adhesive / By using the bonding agent, it is possible to improve the insulation between the dielectric plate and the electrostatic chuck portion and between the dielectric plate and the concave portion, or between the electrostatic chuck portion and the concave portion. Therefore, the plasma density on the surface of the plate-like sample can be made more uniform.

  According to the electrostatic chuck device of the fourteenth aspect of the present invention, the electrostatic adsorption internal electrode is constituted by a plurality of concentric electrode parts insulated from each other, and a power feeding terminal is connected to each of these electrode parts. Therefore, when a high-frequency voltage is applied, it is possible to effectively prevent the high-frequency current from flowing toward the outer edge via the internal electrode for electrostatic adsorption, and the plasma distribution having a higher density at the center. Can be further planarized.

  According to the electrostatic chuck device of the fifteenth aspect of the present invention, the central portion of the electrostatic adsorption internal electrode has an area of 1/9 or more and 4/9 or less of the total area of the electrostatic adsorption internal electrode. Since an opening is formed and this opening is filled with an insulating material, when a high-frequency voltage is applied, the high-frequency current is effectively prevented from flowing toward the outer edge via the internal electrode for electrostatic attraction. It is possible to further flatten the plasma distribution having a higher density at the center.

The best mode for carrying out the electrostatic chuck device and the plasma processing apparatus of the present invention will be described.
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 showing a monopolar electrostatic chuck device according to a first embodiment of the present invention. This electrostatic chuck device 21 includes an electrostatic chuck portion 22, a metal base portion 23, and a dielectric. The body plate 24 is constituted.
The electrostatic chuck portion 22 has a disk-like base 26 having an upper surface (one main surface) on which the plate-like sample W is placed and a built-in electrostatic adsorption internal electrode 25, and the electrostatic adsorption inner portion. The power supply terminal 27 applies a DC voltage to the electrode 25.

  The base body 26 has a disk-shaped mounting plate 31 whose upper surface 31 a is a mounting surface for mounting a plate-like sample W such as a semiconductor wafer, a metal wafer, or a glass plate, and a lower surface of the mounting plate 31. A disk-shaped support plate 32 disposed opposite to the (other main surface) side, a circular internal electrode 25 for electrostatic attraction sandwiched between the mounting plate 31 and the support plate 32, and The inner electrode 25 is mainly composed of an annular insulating material layer 33 provided so as to surround the outer periphery of the inner electrode 25.

On the other hand, in the metal base portion 23, a flow path 28 for circulating a cooling medium such as water or an organic solvent is formed therein, and the temperature of the plate-like sample W placed on the placement surface is set to a desired value. It is comprised so that it can be maintained at temperature. The metal base portion 23 also serves as a high frequency generating electrode.
A circular concave portion 34 is formed on the surface (main surface) of the metal base portion 23 on the electrostatic chuck portion 22 side, and a dielectric is formed in the concave portion 34 via an insulating adhesive / bonding agent layer 35. The plate 24 is bonded and fixed, and the dielectric plate 24 and the support plate 32 of the electrostatic chuck portion 22 are bonded and bonded via an insulating bonding / bonding agent layer 35.

  Here, the dielectric plate 24 and the concave portion 34 are bonded and bonded through an insulating bonding / bonding agent layer 35 having a dielectric constant smaller than that of either the dielectric plate 24 or the support plate 32 of the base 26. When a high frequency voltage is applied to the metal base portion 23, the dielectric plate 24 effectively prevents current from flowing from the peripheral portion to the center portion of the surface of the metal base portion 23 due to the skin effect, The electric field strength on the surface of the chuck portion 22 is made uniform. As a result, the plasma density on the surface of the plate-like sample W is flattened, so that uniform plasma treatment can be performed over the entire surface of the plate-like sample W.

  Further, the dielectric plate 24 and the support plate 32 of the electrostatic chuck unit 22 are connected via an insulating adhesive / bonding agent layer 35 having a dielectric constant smaller than that of either the dielectric plate 24 or the support plate 32 of the base 26. When a high frequency voltage is applied to the metal base portion 23 by bonding and bonding, the high frequency current passes through the insulating adhesive / bonding agent layer 35 and the high frequency current is transmitted through the insulating adhesive / bonding agent layer 35. Thus, the flow toward the outer edge portion is effectively prevented, and the electric field strength on the surface of the electrostatic chuck portion 22 is made uniform. As a result, the plasma density on the surface of the plate-like sample W is flattened, so that uniform plasma treatment can be performed over the entire surface of the plate-like sample W.

  In addition, the thickness of the dielectric plate 24 can be reduced. For example, when an insulating adhesive / bonding agent having a good thermal conductivity is used, the thermal conductivity between the metal base portion 23 and the electrostatic chuck portion 22 is improved. The in-plane thermal uniformity is improved, so that uniform plasma treatment can be performed over the entire surface of the plate-like sample W.

  When the dielectric plate 24 is circular, the clearance between the dielectric plate 24 and the recess 34 is preferably 0.1% or more, more preferably 0.3% or more of the diameter. Further, when the dielectric plate 24 is rectangular, it is preferably 0.1% or more of the diagonal length of the rectangle, more preferably 0.2% or more, and further preferably 0.3% or more.

  Here, the clearance between the dielectric plate 24 and the recess 34 is 0.1% of the diameter when the dielectric plate 24 is circular, and is 0 of the length of the diagonal of the rectangle when the dielectric plate 24 is rectangular. If it is less than 1%, the warp of the metal base part 23 due to the difference in thermal expansion coefficient between the dielectric plate 24 and the metal base part 23 is likely to occur. The base 26 of the chuck portion 22 is damaged, the adhesive / bonding agent layer 35 between the metal base portion 23 and the dielectric plate 24 is peeled off, the base plate 26 of the dielectric plate 24 and the electrostatic chuck portion 22 The adhesive / bonding agent layer 35 may peel off.

Further, the clearance between the dielectric plate 24 and the recess 34 is preferably 2.0 mm or less, more preferably 1.5 mm or less, and still more preferably 1.0 mm or less, according to the numerical range.
If the clearance between the dielectric plate 24 and the recess 34 exceeds 2.0 mm, the in-plane thermal uniformity of the plate-like sample W may be lowered, and the plasma processing may not be made uniform.

The insulating adhesive / bonding agent layer 35 only needs to have a smaller dielectric constant than either the dielectric plate 24 or the support plate 32 of the base 26. For example, the dielectric plate 24 and the support plate 32 are made of aluminum oxide. Addition of aluminum nitride smaller in dielectric constant than aluminum oxide (Al ₂ O ₃ ) sintered body and aluminum nitride (AlN) sintered body when made of (Al ₂ O ₃ ) sintered body or aluminum nitride (AlN) sintered body A silicone-based adhesive / bonding agent is preferred.

  Here, the reason why the dielectric constant of the insulating adhesive / bonding agent layer 35 is smaller than that of either the dielectric plate 24 or the support plate 32 is that between the electrostatic adsorption internal electrode 25 and the metal base portion 23. The electric capacity of the electrostatic chuck portion 22 can be reduced, the electric field strength at the center portion of the electrostatic chuck portion 22 can be lowered more effectively, the plasma can be made uniform, and the responsiveness of the electrostatic adsorption force can be improved. It is.

The thermal conductivity of the insulating adhesive-bonding agent layer 35 is preferably at least 0.3 W / ^{m 2} K, more preferably 0.5 W / ^{m 2} K or more, more preferably 1.0 W / ^{m 2} K or more It is.
Here, the reason why the thermal conductivity of the insulating adhesive / bonding agent layer 35 is limited to 0.3 W / m ² K or more is that if the thermal conductivity is less than 0.3 W / m ² K, the thermal conductivity is less than 0.3 W / m ² K. This is because the thermal conductivity to the plate-like sample W is lowered and it becomes difficult to maintain the plate-like sample W at a desired constant temperature.

  With respect to the insulating adhesive / bonding agent layer 35, the dielectric plate is disposed between the metal base portion 23 and the dielectric plate 24 so that the thermal conductivity is the same over the entire adsorption region of the electrostatic chuck portion 22. 24 and the support plate 32 of the electrostatic chuck portion 22, the heat conduction between the electrostatic chuck portion 22 and the metal base portion 23 is adjusted by adjusting the material and thickness of each insulating adhesive / bonding agent layer 35. The rate can be made uniform, and the in-plane thermal uniformity of the plate-like sample W can be improved.

For example, when the shape of the dielectric plate 24 is a concentric stepped or conical shape with a thick central part and a thin peripheral part, the central part of the insulating adhesive / bonding agent layer 35 is thin and the peripheral part is thick. do it.
Thereby, the in-plane thermal uniformity of the plate-like sample W is improved, and the plasma processing is made uniform.

Further, a power feeding terminal insertion hole 36 is formed in the vicinity of the central portion of the support plate 32 and the metal base portion 23, and a DC voltage is applied to the electrostatic suction internal electrode 25 in the power feeding terminal insertion hole 36. A power feeding terminal 27 is inserted through a cylindrical insulator 37. The upper end of the power feeding terminal 27 is electrically connected to the electrostatic adsorption internal electrode 25.
Further, the mounting plate 31, the support plate 32, the electrostatic adsorption internal electrode 25, and the metal base portion 23 are formed with a cooling gas introduction hole 38 penetrating them, and the mounting plate 31 is formed by the cooling gas introduction hole 38. A cooling gas such as He is supplied to the gap between the plate-like sample W and the lower surface of the plate-like sample W.

An upper surface 31a of the mounting plate 31 is an electrostatic adsorption surface on which a single plate-like sample W is mounted and electrostatically adsorbs the plate-like sample W by electrostatic adsorption force. ) 31a is provided with a plurality of cylindrical protrusions (not shown) having a substantially circular cross section along the upper surface 31a, and the top surfaces of these protrusions are parallel to the upper surface 31a.
In addition, a wall (not shown) that is continuous along the peripheral edge and has the same height as the protrusion is provided at the peripheral edge of the upper surface 31a so that a cooling gas such as He does not leak. It is formed so as to go around the peripheral edge of the upper surface 31a.

  The electrostatic chuck device 21 configured as described above is mounted in a chamber of a plasma processing apparatus such as a plasma etching apparatus, and a plate-like sample W is mounted on an upper surface 31a which is a mounting surface, and an electrostatic chucking inner part is mounted. By applying a predetermined DC voltage to the electrode 25 via the power feeding terminal 27, the plate-like sample W is adsorbed and fixed using electrostatic force, and the metal base portion 23 also serving as a high-frequency generating electrode and the chamber By applying a high-frequency voltage between them to generate plasma on the mounting plate 31, the plate-like sample W can be subjected to various plasma treatments.

Next, each component of the electrostatic chuck device will be described in more detail.
"Mounting plate and support plate"
Both the mounting plate 31 and the support plate 32 are made of ceramics.
Examples of the ceramic include aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ ), silicon nitride (Si ₃ N ₄ ), zirconium oxide (ZrO ₂ ), sialon, boron nitride (BN), and silicon carbide (SiC). The selected one type of ceramics or composite ceramics containing two or more types is preferred.

In addition, the material constituting these may be a single material or a mixture, but those having a thermal expansion coefficient that is as close as possible to the thermal expansion coefficient of the internal electrode 25 and that are easy to sinter. preferable. Further, since the upper surface 31a side of the mounting plate 31 is an electrostatic adsorption surface, it is preferable to select a material 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. .
In consideration of the above, the mounting plate 31 and the support plate 32 substantially contain 1 to 20% by weight of silicon carbide, with the remainder being aluminum oxide. The body is preferred.

As this silicon carbide-aluminum oxide composite sintered body, a composite sintered body composed of aluminum oxide (Al ₂ O ₃ ) and silicon carbide (SiC) whose surface is coated with silicon oxide (SiO ₂ ) is used. When the content of SiC) is 5% by weight or more and 15% by weight or less with respect to the entire composite sintered body, the volume resistivity at room temperature (25 ° C.) is 1.0 × 10 ¹⁴ Ω · cm or more, and Coulomb It is suitable as a mounting plate 31 for a type electrostatic chuck device. Furthermore, it has excellent wear resistance, does not cause wafer contamination or particle generation, and has improved plasma resistance.

Moreover, as this silicon carbide-aluminum oxide composite sintered body, a composite sintered body made of aluminum oxide (Al ₂ O ₃ ) and silicon carbide (SiC) is used, and the content of silicon carbide (SiC) is changed to a composite sintered body. When it is 5 wt% or more and 15 wt% or less with respect to the whole, the volume resistivity at room temperature (25 ° C.) is 1.0 × 10 ⁹ Ω · cm or more and 1.0 × 10 ¹² Ω · cm or less, It is suitable as the mounting plate 31 of the Johnson-Rahbek type electrostatic chuck device. Furthermore, it has excellent wear resistance, does not cause wafer contamination or particle generation, and has improved plasma resistance.

Moreover, the average particle diameter of the silicon carbide particles in this silicon carbide-aluminum oxide composite sintered body is preferably 0.2 μm or less.
When the average particle diameter of the silicon carbide particles exceeds 0.2 μm, the electric field during plasma irradiation concentrates on the silicon carbide particles in the silicon carbide-aluminum oxide composite sintered body, and the periphery of the silicon carbide particles is damaged. It is because it becomes easy.

The average particle diameter of the aluminum oxide particles in the silicon carbide-aluminum oxide composite sintered body is preferably 2 μm or less.
This is because if the average particle diameter of the aluminum oxide particles exceeds 2 μm, the silicon carbide-aluminum oxide composite sintered body is plasma-etched, and it becomes easy to form sputter marks and the surface roughness becomes rough.

"Electrode for electrostatic adsorption"
The electrostatic chucking internal electrode 25 is made of a plate-like ceramic having a thickness of about 10 μm to 50 μm, and has a volume specific resistance of 1.0 × 10 ⁻¹ Ω · cm or more at an operating temperature of the electrostatic chuck device. It is preferably 1.0 × 10 ⁸ Ω · cm or less, more preferably 1.0 × 10 ² Ω · cm or more and 1.0 × 10 ⁴ Ω · cm or less.

Here, the reason why the range of the volume resistivity is limited as described above is that when the volume resistivity falls below 1.0 × 10 ⁻¹ Ω · cm, a high frequency voltage is applied to the metal base portion 23. This is because the current cannot pass through the internal electrode 25 for electrostatic adsorption, the electric field strength on the surface of the electrostatic chuck portion 22 cannot be made uniform, and therefore the plasma cannot be made uniform. On the other hand, when the volume resistivity exceeds 1.0 × 10 ⁸ Ω · cm, the electrostatic adsorption internal electrode 25 becomes substantially an insulator, and the function as the electrostatic adsorption internal electrode can be exhibited. This is because the electrostatic attraction force cannot be developed, or the response of the electrostatic attraction force is lowered and it takes a long time until the required electrostatic attraction force is developed.

Examples of ceramics constituting the internal electrode 25 for electrostatic attraction include various composite sintered bodies as follows.
(1) A composite sintered body obtained by adding semiconductor ceramics such as silicon carbide (SiC) to insulating ceramics such as aluminum oxide.
(2) A composite sintered body obtained by adding conductive ceramics such as tantalum nitride (TaN), tantalum carbide (TaC), molybdenum carbide (Mo ₂ C) to insulating ceramics such as aluminum oxide.
(3) A composite sintered body obtained by adding a high melting point metal such as molybdenum (Mo), tungsten (W), or tantalum (Ta) to an insulating ceramic such as aluminum oxide.
(4) A composite sintered body obtained by adding a conductive material such as carbon (C) to insulating ceramics such as aluminum oxide.

These materials easily control the volume resistivity within the range of 1.0 × 10 ⁻¹ Ω · cm or more and 1.0 × 10 ⁸ Ω · cm or less by controlling the addition amount of the conductive component. be able to. In particular, when both the mounting plate 31 and the support plate 32 are formed of ceramics, the coefficients of thermal expansion are approximated, which is suitable as a material for forming the electrostatic adsorption internal electrode 25.

The shape and size of the internal electrode 25 for electrostatic attraction can be adjusted as appropriate. Further, the entire region of the electrostatic adsorption internal electrode 25 is formed of a material having a volume resistivity within a range of 1.0 × 10 ⁻¹ Ω · cm to 1.0 × 10 ⁸ Ω · cm. It is not necessary that 50% or more, preferably 70% or more of the total area of the electrostatic attraction internal electrode 25 is 1.0 × 10 ⁻¹ Ω · cm or more and 1.0 × 10 ⁸ Ω · cm or less. It is sufficient that it is made of a material having a volume resistivity within the range of.

"Insulation layer"
The insulating material layer 33 is for bonding and integrating the mounting plate dielectric plate 31 and the support plate 32, and for protecting the electrostatic adsorption internal electrode 25 from plasma and corrosive gas. It is. The material constituting the insulating material layer 33 is preferably an insulating material whose main component is the same as that of the mounting plate 31 and the supporting plate 32. For example, the mounting plate 31 and the supporting plate 32 are made of silicon carbide-aluminum oxide composite firing. In the case where it is constituted by a bonded body, it is preferable to use aluminum oxide (Al ₂ O ₃ ).

"Dielectric plate"
The dielectric plate 24 embedded in the metal base portion 23 is for reducing the electric field strength at the central portion of the electrostatic chuck portion 22, and the electrostatic chuck portion when high frequency power is applied to the metal base portion 23. The electric field strength on the surface of 22 is further uniformized. Thereby, the plasma density is further uniformized.
Such a dielectric plate 24 is preferably a ceramic having excellent insulation and good thermal conductivity, such as an aluminum oxide (Al ₂ O ₃ ) sintered body, an aluminum nitride (AlN) sintered body, and the like. Can be mentioned.

The thickness of the dielectric plate 24 is preferably 2 mm or more and 15 mm or less, more preferably 4 mm or more and 8 mm or less.
If the thickness of the dielectric plate 24 is less than 2 mm, an effect sufficient to reduce the electric field strength at the center of the electrostatic chuck portion 22 cannot be obtained, while if the thickness of the dielectric plate 24 exceeds 15 mm. The thermal conductivity from the metal base portion 23 to the plate-like sample W is lowered, and it becomes difficult to maintain the plate-like sample W at a desired constant temperature.

The insulating adhesive / bonding agent layer 35 for adhering / bonding the dielectric plate 24 and the support plate 32 of the electrostatic chuck portion 22 is not particularly limited as long as it has excellent insulating properties. A material obtained by adding an aluminum nitride (AlN) powder or an alumina (Al ₂ O ₃ ) powder, which is an insulating ceramic, to a silicone adhesive is preferably used.

Here, the reason why the insulating adhesive / bonding agent layer 35 is used is that when the dielectric plate 24 and the support plate 32 are bonded / bonded via the conductive adhesive / bonding agent layer, the high-frequency current becomes conductive. This is because it cannot pass through the adhesive / bonding agent layer and flows in the direction of the outer edge along the conductive adhesive / bonding agent layer, making it impossible to achieve uniform plasma.
Here, the dielectric plate 24 is bonded and fixed in the recess 34 via the insulating adhesive / bonding agent layer 35, but the bonding / bonding portion between the dielectric plate 24 and the recess 34 is complementary. The dielectric plate 24 and the recess 34 may be fitted.

"Manufacturing method of electrostatic chuck device"
A method for manufacturing the electrostatic chuck device of this embodiment will be described.
Here, the case where the mounting plate 31 and the support plate 32 are manufactured using a silicon carbide-aluminum oxide composite sintered body substantially containing 1 wt% to 20 wt% silicon carbide will be described as an example.
As the raw material powder of silicon carbide (SiC) to be used, it is preferable to use silicon carbide powder having an average particle size of 0.1 μm or less.

The reason is that when the average particle diameter of silicon carbide (SiC) powder exceeds 0.1 μm, the obtained silicon carbide-aluminum oxide composite sintered body has an average particle diameter of silicon carbide particles exceeding 0.2 μm. This is because the effect of improving the strength of the mounting plate 31 and the support plate 32 is reduced.
In addition, the mounting plate 31 made of this silicon carbide-aluminum oxide composite sintered body is easily damaged when the electric field is concentrated on the silicon carbide (SiC) particles when exposed to plasma. This is because the electrostatic adsorption force after plasma damage may be reduced.

As this silicon carbide (SiC) powder, a powder obtained by a plasma CVD method is preferable, and in particular, a silane compound or silicon halide and hydrocarbon source gas is introduced into the plasma in a non-oxidizing atmosphere, and the reaction system Ultrafine powder having an average particle diameter of 0.1 μm or less obtained by performing a gas phase reaction while controlling the pressure in the range of 1 × 10 ⁵ Pa (1 atm) to 1.33 × 10 Pa (0.1 Torr) However, it is preferable since it has excellent sinterability, high purity, and good particle dispersibility during molding due to its spherical shape.

On the other hand, the raw material powder of aluminum oxide _(Al 2 _{0 3),} the following aluminum oxide average particle diameter of 1μm _(Al 2 _{0 3)} is preferably used powder.
The reason is that aluminum oxide (Al 2 _{0 3)} silicon carbide was obtained using a powder having an average particle size exceeds 1 [mu] m - In the aluminum oxide composite sintered body, aluminum oxide in the composite sintered body (Al ₂ 0 ₃ ) Since the average particle diameter of the particles exceeds 2 μm, the upper surface 31a on the side of the mounting plate 31 on which the plate-like sample is placed is easily etched by the plasma, so that sputter marks are formed. This is because the surface roughness of the upper surface 31a becomes rough, and the electrostatic chucking force of the electrostatic chuck device 21 may be reduced.
The aluminum oxide (Al ₂ 0 ₃ ) powder to be used is not particularly limited as long as it has an average particle diameter of 1 μm or less and high purity.

Next, the silicon carbide (SiC) powder and the aluminum oxide (Al ₂ O ₃ ) powder are weighed and mixed so that a desired volume specific resistance value can be obtained.
Next, the obtained mixed powder is molded into a predetermined shape using a mold, and then the obtained molded body is fired while being pressed using, for example, a hot press (HP), and silicon carbide-oxidized An aluminum composite sintered body is obtained.

  As the conditions for hot pressing (HP), the applied pressure is not particularly limited, but when obtaining a silicon carbide-aluminum oxide composite sintered body, for example, 5-40 MPa is preferable. This is because if the applied pressure is less than 5 MPa, a composite sintered body having a sufficient sintered density cannot be obtained, while if the applied pressure exceeds 40 MPa, a jig made of graphite or the like is deformed and worn.

Moreover, as a temperature at the time of baking, 1650-1850 degreeC is preferable. When the firing temperature is less than 1650 ° C., a sufficiently dense silicon carbide-aluminum oxide composite sintered body cannot be obtained. On the other hand, when the firing temperature exceeds 1850 ° C., decomposition and grain growth of the sintered body occur during the firing process. This is because it tends to occur.
Moreover, as an atmosphere at the time of baking, inert atmospheres, such as argon atmosphere and nitrogen atmosphere, are preferable from a viewpoint of preventing the oxidation of silicon carbide.
Of the two silicon carbide-aluminum oxide composite sintered bodies obtained in this manner, a power supply terminal insertion hole 36 is formed by machining at a predetermined position of one composite sintered body to form a support plate 32. .

In addition, as a coating agent for forming the internal electrode for electrostatic adsorption, an electrically conductive material powder such as molybdenum carbide (Mo ₂ C) is electrostatically applied to an insulating ceramic powder such as aluminum oxide (Al ₂ O ₃ ). A paste-like coating agent is prepared by adding the specific volume resistance of the chuck device at a working temperature of 1.0 × 10 ⁻¹ Ω · cm to 1.0 × 10 ⁸ Ω · cm. Then, this coating agent is applied to the region of the support plate 32 where the internal electrode for electrostatic attraction is formed to form a conductive layer, and aluminum oxide (Al ₂ 0 is applied to the region outside the region where the conductive layer is formed. ₃ ) Apply a pasted coating agent containing an insulating ceramic powder such as ₁ ) to form an insulating layer.

  Next, the power supply terminal 27 is inserted into the power supply terminal insertion hole 36 of the support plate 32 via the cylindrical insulator 37, the surface of the support plate 32 on which the conductive layer and the insulating layer are formed, and the mounting plate Next, the mounting plate 31 and the support plate 32 are pressurized while being heated to, for example, 1600 ° C. or more to form the internal electrode 25 for electrostatic adsorption by the conductive layer, and the insulating layer. Thus, an insulating material layer 33 to be a bonding layer is formed, and the mounting plate 31 and the support plate 32 are bonded to each other through the electrostatic attraction internal electrode 25 and the insulating material layer 33. Then, the upper surface 31a of the mounting plate 31 serving as the mounting surface is polished so that Ra (center line average roughness) is 0.3 μm, and the electrostatic chuck portion 22 is obtained.

On the other hand, an aluminum (Al) plate is used to produce a metal base portion 23 in which a circular recess 34 is formed on the surface and a flow path 28 for circulating a cooling medium is formed inside. Further, aluminum oxide (Al ₂ O ₃ ) powder is molded and fired to produce a dielectric plate 24 made of an aluminum oxide sintered body.
Next, an insulating adhesive / bonding agent is applied to the entire inner surface of the recess 34 of the metal base portion 23, and then a dielectric plate 24 is bonded / bonded onto the insulating adhesive / bonding agent. An insulating adhesive / bonding agent is applied on the metal base portion 23 including 24, and the electrostatic chuck portion 22 is bonded / bonded onto the insulating adhesive / bonding agent.

  In this bonding / bonding, for example, the thermal conductivity at the center of the electrostatic chuck portion 22 and the electrostatic chuck portion 22 are set so that the thermal conductivity is the same over the entire adsorption region of the electrostatic chuck portion 22. By adjusting the material of the adhesive / bonding agent and the thickness at the time of application so that the thermal conductivity at the periphery is the same, the in-plane thermal uniformity of the plate-like sample W can be improved, and the plasma treatment is made uniform. Can be achieved.

In this bonding / bonding process, the dielectric plate 24 is bonded and fixed in the recess 34 of the metal base portion 23 via an insulating bonding / bonding agent layer 35, and the support plate 32 of the electrostatic chuck portion 22 is It is bonded and fixed to the metal base portion 23 and the dielectric plate 24 via an insulating bonding / bonding agent layer 35.
As described above, the electrostatic chuck device of this embodiment can be obtained.

  As described above, according to the electrostatic chuck device of the present embodiment, the circular concave portion 34 is formed on the surface of the metal base portion 23 on the electrostatic chuck portion 22 side, and the insulating adhesion is formed in the concave portion 34. The dielectric plate 24 is bonded and fixed via the bonding agent layer 35, and the dielectric plate 24 and the support plate 32 of the electrostatic chuck portion 22 are bonded and bonded via the insulating bonding and bonding agent layer 35. Since the dielectric constant of the insulating adhesive / bonding agent layer 35 is smaller than that of either the dielectric plate 24 or the support plate 32 of the base 26, the plasma density on the surface of the plate-like sample W is flattened. It is possible to perform uniform plasma treatment over the entire surface of the plate-like sample W.

[Second Embodiment]
FIG. 2 is a cross-sectional view showing the electrostatic chuck device of the second embodiment of the present invention. The electrostatic chuck device 41 of the present embodiment is different from the electrostatic chuck device 21 of the first embodiment in that On the surface (main surface) of the metal base portion 23 on the electrostatic chuck portion 22 side, a concave portion 42 having the same shape as the lower surface of the electrostatic chuck portion 22 and having a depth smaller than the height of the electrostatic chuck portion 22 is formed. Then, the concave portion 42 and the support plate 32 below the electrostatic chuck portion 22 are bonded and bonded via an insulating bonding / bonding agent layer 35 having a dielectric constant smaller than that of the support plate 32 constituting the base 26. Is a point.

  In this electrostatic chuck device, the electrostatic chuck portion 22 and the concave portion 42 are bonded and bonded through an insulating bonding / bonding agent layer 35 having a dielectric constant smaller than that of the support plate 32 constituting the base body 26. When a high frequency voltage is applied to the metal base part 23, the electrostatic chuck part 22 effectively prevents the current from flowing from the peripheral part of the surface of the metal base part 23 toward the center part due to the skin effect, The electric field strength on the surface of the chuck part is made uniform.

  When the substrate 26 is circular, the clearance between the recess 42 and the substrate 26 is preferably 0.1% or more of the diameter, more preferably 0.2% or more, and further preferably 0.3% or more. Further, when the substrate 26 is rectangular, it is preferably 0.1% or more of the length of the diagonal line, more preferably 0.2% or more, and further preferably 0.3% or more.

Here, if the clearance between the recess 34 and the base body 26 is less than 0.1%, the metal base portion 23 is likely to warp due to the difference in thermal expansion coefficient between the base body 26 and the metal base portion 23. As a result, the base 26 of the electrostatic chuck portion 22 may be damaged, or the adhesive / bonding agent layer 35 between the metal base portion 23 and the base 26 may be peeled off.
Further, the clearance between the recess 42 and the base body 26 is preferably 2.0 mm or less, more preferably 1.5 mm or less, and further preferably 1.0 mm or less as a numerical range.
If the clearance between the recess 42 and the substrate 26 exceeds 2.0 mm, the in-plane thermal uniformity of the plate-like sample W may be lowered, and the plasma processing may not be made uniform.

According to the electrostatic chuck device 41 of the present embodiment, the concave portion 42 and the support plate 32 below the electrostatic chuck portion 22 are connected via the insulating adhesive / bonding agent layer 35 having a dielectric constant smaller than that of the support plate 32. Thus, the plasma density on the surface of the plate-like sample W can be flattened, and uniform plasma treatment can be performed over the entire surface of the plate-like sample W.
Further, positioning and fixing between the metal base portion 23 and the electrostatic chuck portion 22 can be easily and reliably performed.

[Third Embodiment]
FIG. 3 is a cross-sectional view showing a dielectric plate of an electrostatic chuck device according to a third embodiment of the present invention. The dielectric plate 51 of the present embodiment is different from the dielectric plate 24 of the first embodiment. Is that the lower surface 51a of the dielectric plate 51 is conical so that the thickness of the dielectric plate 51 gradually decreases concentrically from the central portion toward the peripheral portion.
When the dielectric plate 51 is used, if the concave portion 52 complementary to the lower surface 51a of the dielectric plate 51 is formed in the metal base portion 23, positioning and fixing between the metal base portion 23 and the dielectric plate 51 are easy and fixed. Be certain.

According to the dielectric plate 51 of the present embodiment, since the thickness is gradually reduced concentrically from the central portion toward the peripheral portion, the plasma distribution that is denser in the central portion can be flattened. The plasma density on the surface of the plate sample can be made more uniform.
Further, if the concave portion 52 complementary to the lower surface 51a of the dielectric plate 51 is formed in the metal base portion 23, the positioning and fixing between the metal base portion 23 and the dielectric plate 51 can be performed easily and reliably. it can.

[Fourth Embodiment]
FIG. 4 is a cross-sectional view showing a dielectric plate of an electrostatic chuck device according to a fourth embodiment of the present invention. The dielectric plate 61 of this embodiment is different from the dielectric plate 24 of the first embodiment. The point is that the lower surface 61a of the dielectric plate 61 has a stepped cross section so that the thickness of the dielectric plate 61 gradually decreases concentrically from the central portion toward the peripheral portion.
When this dielectric plate 61 is used, if the concave portion 62 complementary to the lower surface 61a of the dielectric plate 61 is formed in the metal base portion 23, positioning and fixing between the metal base portion 23 and the dielectric plate 61 are easy and fixed. Be certain.

According to the dielectric plate 61 of the present embodiment, since the thickness is gradually reduced in a concentric manner from the central portion toward the peripheral portion, the plasma distribution that is denser in the central portion is flattened. And the plasma density on the surface of the plate-like sample can be made more uniform.
Further, if the concave portion 62 complementary to the lower surface 61a of the dielectric plate 61 is formed in the metal base portion 23, the positioning and fixing between the metal base portion 23 and the dielectric plate 61 can be easily and reliably performed. it can.

[Fifth Embodiment]
FIG. 5 is a cross-sectional view showing a support plate of an electrostatic chuck device according to a fifth embodiment of the present invention. The support plate 71 of this embodiment is different from the support plate 32 of the second embodiment in that the support plate The lower surface 71a of the support plate 71 is conical so that the thickness of the plate 71 gradually decreases concentrically from the central portion toward the peripheral portion.
When the support plate 71 is used, if the concave portion 72 complementary to the lower surface 71a of the support plate 71 is formed in the metal base portion 23, positioning and fixing between the metal base portion 23 and the support plate 71 become easy and reliable. .

According to the support plate 71 of the present embodiment, since the thickness is gradually reduced concentrically from the central portion toward the peripheral portion, the plasma distribution that is denser toward the central portion can be flattened, The plasma density on the surface of the plate-like sample can be made more uniform.
Further, if the concave portion 72 complementary to the lower surface 71a of the support plate 71 is formed in the metal base portion 23, the positioning and fixing between the metal base portion 23 and the support plate 71 can be performed easily and reliably.

[Sixth Embodiment]
FIG. 6 is a cross-sectional view showing a support plate of an electrostatic chuck device according to a sixth embodiment of the present invention. The support plate 81 of this embodiment is different from the support plate 32 of the second embodiment in that the support plate The lower surface 81a of the support plate 81 has a stepped cross section so that the thickness of the plate 81 decreases concentrically and gradually from the central portion toward the peripheral portion.
When the support plate 81 is used, if the concave portion 82 complementary to the lower surface 81a of the support plate 81 is formed in the metal base portion 23, the positioning and fixing between the metal base portion 23 and the support plate 81 are easy and reliable. .

According to the support plate 81 of the present embodiment, since the thickness is concentrically and gradually decreased from the central portion toward the peripheral portion, it is possible to flatten the plasma distribution that is denser toward the central portion. And the plasma density on the surface of the plate-like sample can be made more uniform.
Further, if the concave portion 82 complementary to the lower surface 81a of the support plate 81 is formed in the metal base portion 23, the positioning and fixing between the metal base portion 23 and the support plate 81 can be performed easily and reliably.

[Seventh Embodiment]
FIG. 7 is a cross-sectional view showing a base body of an electrostatic chuck device according to a seventh embodiment of the present invention. The difference between the base body 91 of the present embodiment and the base body 26 of the first embodiment is the mounting plate 31. The internal electrode for electrostatic attraction sandwiched between the support plate 32 and the support plate 32 is composed of a plurality of concentric electrode portions 93 to 95, and an insulating material between each of these electrode portions 93 to 95 and in the center portion. A layer 96 is formed, and the power feeding terminals 27 are connected to the electrode portions 93 to 95, respectively, and the power feeding terminals 27 are grounded via a DC power source 97.

  According to the electrostatic chuck device of this embodiment, the internal electrode for electrostatic attraction is constituted by a plurality of concentric electrode portions 93 to 95, and the insulating material layer 96 is provided between these electrode portions 93 to 95 and in the center. Since the power supply terminals 27,... Are connected to the electrode portions 93 to 95, respectively, even when a high frequency voltage is applied, the high frequency current is prevented from flowing through the electrostatic adsorption internal electrode. It is possible to flatten the plasma distribution, which has a higher density at the center.

[Eighth Embodiment]
FIG. 8 is a cross-sectional view showing a base body of a bipolar electrostatic chuck apparatus according to the eighth embodiment of the present invention. The base body 101 of the present embodiment differs from the base body 91 of the seventh embodiment in that there are a plurality of points. A DC power source 97 is connected to each of the electrode portions 93 to 95 via power feeding terminals 27 and 27 to form a bipolar electrostatic chuck device.
In this embodiment, the same effect as that of the seventh embodiment can be obtained.

[Ninth Embodiment]
FIG. 9 is a plan view showing an internal electrode for electrostatic attraction of an electrostatic chuck device according to a ninth embodiment of the present invention, and the internal electrode for electrostatic attraction 111 of the present embodiment is the static of the first embodiment. A difference from the electroadsorption internal electrode 25 is that a circular opening 112 having an area of 1/9 to 4/9 of the total area of the electrostatic adsorption internal electrode 111 is formed at the center. 112 is filled with an insulating material layer 96.

  In the electrostatic adsorption internal electrode 111, an opening 112 having an area of 1/9 or more and 4/9 or less of the total area of the electrostatic adsorption internal electrode 111 is formed in the center, and the opening 112 is formed as an insulating material. By filling with the layer 96, even when a high-frequency voltage is applied, the high-frequency current is less likely to flow toward the outer edge portion via the electrostatic adsorption internal electrode 111, and the central portion has a higher density. The plasma distribution is flattened.

  According to the electrostatic chuck device of this embodiment, the opening 112 having an area of 1/9 or more and 4/9 or less of the total area of the electrostatic adsorption internal electrode 111 is formed in the central portion of the electrostatic adsorption internal electrode 111. Since the opening 112 is filled with the insulating material layer 96, even when a high frequency voltage is applied, the high frequency current flows toward the outer edge via the electrostatic adsorption internal electrode 111. It is possible to prevent the plasma distribution, which is higher in density at the center, and to be flattened.

[Tenth embodiment]
FIG. 10 is a plan view showing an internal electrode for electrostatic attraction of an electrostatic chuck device according to a tenth embodiment of the present invention, and the internal electrode 121 for electrostatic attraction of the present embodiment is the static of the ninth embodiment. The difference from the electroadsorption internal electrode 111 is that the overall shape is rectangular, and the central portion has a rectangular shape with an area of 1/9 to 4/9 of the total area of the electrostatic adsorption internal electrode 121. An opening 122 is formed, and the opening 122 is filled with an insulating material layer 96.
In this embodiment, the same effect as that of the ninth embodiment can be obtained.

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. It is sectional drawing which shows the dielectric material board of the electrostatic chuck apparatus of the 3rd Embodiment of this invention. It is sectional drawing which shows the dielectric material board of the electrostatic chuck apparatus of the 4th Embodiment of this invention. It is sectional drawing which shows the support plate of the electrostatic chuck apparatus of the 5th Embodiment of this invention. It is sectional drawing which shows the support plate of the electrostatic chuck apparatus of the 6th Embodiment of this invention. It is sectional drawing which shows the base | substrate of the electrostatic chuck apparatus of the 7th Embodiment of this invention. It is sectional drawing which shows the base | substrate of the electrostatic chuck apparatus of the 8th Embodiment of this invention. It is a top view which shows the internal electrode for electrostatic attraction of the electrostatic chuck apparatus of the 9th Embodiment of this invention. It is a top view which shows the internal electrode for electrostatic attraction of the electrostatic chuck apparatus of the 10th Embodiment of this invention. It is sectional drawing which shows an example of the conventional electrostatic chuck apparatus. It is sectional drawing which shows an example of the conventional plasma processing apparatus. It is sectional drawing which shows an example of the plasma processing apparatus by which the conventional electrostatic chuck apparatus was mounted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Electrostatic chuck apparatus 22 Electrostatic chuck part 23 Metal base part 24 Dielectric board 25 Electrostatic adsorption internal electrode 26 Base body 27 Power supply terminal 28 Flow path 31 Mounting plate 31a Upper surface 32 Support plate 33 Insulating material layer 34 Recessed part 35 Insulating adhesive / bonding agent layer 36 Feeding terminal insertion hole 37 insulator 38 cooling gas introduction hole 41 electrostatic chuck device 42 recess 51 dielectric plate 51a bottom surface 52 recess 61 dielectric plate 61a bottom surface 62 recess 71 support plate 71a bottom surface 72 Recessed portion 81 Support plate 81a Lower surface 82 Recessed portion 91 Base body 93 to 95 Electrode portion 96 Insulating material layer 97 DC power source 101 Base body 111 Electrostatic chucking internal electrode 112 Opening 121 Electrostatic chucking internal electrode 121 Opening W Plate sample

Claims (16)

A static surface having a main surface as a mounting surface on which a plate-like sample is placed and a built-in electrostatic adsorption internal electrode, and a power supply terminal for applying a DC voltage to the electrostatic adsorption internal electrode. An electric chuck,
It is fixed to and integrated with the other main surface of the base of the electrostatic chuck portion, and includes a metal base portion that serves as a high-frequency generating electrode.
A concave portion is formed in the main surface of the metal base portion on the electrostatic chuck portion side, and a dielectric plate is fixed in the concave portion,
The dielectric plate and the electrostatic chuck portion are bonded and bonded via an insulating adhesive / bonding agent layer having a dielectric constant smaller than that of either the dielectric plate or the base body,
The dielectric plate and the recess are bonded / bonded via an insulating adhesive / bonding agent layer having a dielectric constant smaller than that of either the dielectric plate or the substrate ,
The electrostatic chuck apparatus characterized in that a volume specific resistance of the internal electrode for electrostatic adsorption is 1.0 × 10 ⁻¹ Ω · cm or more and 1.0 × 10 ⁸ Ω · cm or less .   The electrostatic chuck apparatus according to claim 1, wherein the dielectric plate has a thickness that decreases from a central portion toward a peripheral portion.   The clearance between the dielectric plate and the recess is 0.1% or more of the diameter when the dielectric plate is circular, and is 0. 0 of the diagonal length of the rectangle when the dielectric plate is rectangular. The electrostatic chuck device according to claim 1, wherein the electrostatic chuck device is 1% or more.   4. The electrostatic chuck device according to claim 1, wherein a clearance between the dielectric plate and the recess is 2.0 mm or less.   5. The electrostatic chuck device according to claim 1, wherein the concave portion has a shape complementary to a main surface of the dielectric plate on the concave portion side.   6. The thermal conductivity between the electrostatic chuck portion and the metal base portion is uniform over the entire adsorption region of the electrostatic chuck portion. Electrostatic chuck device. A static surface having a main surface as a mounting surface on which a plate-like sample is placed and a built-in electrostatic adsorption internal electrode, and a power supply terminal for applying a DC voltage to the electrostatic adsorption internal electrode. An electric chuck,
It is fixed to and integrated with the other main surface of the base of the electrostatic chuck portion, and includes a metal base portion that serves as a high-frequency generating electrode.
A concave portion is formed on the main surface of the metal base portion on the electrostatic chuck portion side, and the electrostatic chuck portion is fixed to the concave portion,
The electrostatic chuck portion and the concave portion are bonded and bonded via an insulating adhesive / bonding agent layer having a dielectric constant smaller than that of the substrate ,
The electrostatic chuck apparatus characterized in that a volume specific resistance of the internal electrode for electrostatic adsorption is 1.0 × 10 ⁻¹ Ω · cm or more and 1.0 × 10 ⁸ Ω · cm or less .   The electrostatic chuck apparatus according to claim 7, wherein the thickness of the base body decreases from a central portion toward a peripheral portion.   The clearance between the base and the recess is at least 0.1% of the diameter when the base is circular, and at least 0.1% of the diagonal length of the rectangle when the base is rectangular. 9. The electrostatic chuck device according to claim 7 or 8, wherein:   The electrostatic chuck apparatus according to claim 7, 8 or 9, wherein a clearance between the base and the recess is 2.0 mm or less.   The electrostatic chuck apparatus according to claim 7, wherein the recess has a shape complementary to the other main surface of the base.   The thermal conductivity between the electrostatic chuck portion and the metal base portion is uniform over the entire adsorption region of the electrostatic chuck portion. Electrostatic chuck device.   13. The electrostatic chuck device according to claim 1, wherein the insulating adhesive / bonding agent layer is made of an aluminum nitride-added silicone adhesive / bonding agent.   14. The electrostatic attraction internal electrode comprises a plurality of concentric electrode parts insulated from each other, and the power feeding terminal is connected to each of the electrode parts. The electrostatic chuck device according to claim 1.   An opening having an area of 1/9 or more and 4/9 or less of the total area of the electrostatic adsorption internal electrode is formed in the central portion of the electrostatic adsorption internal electrode, and this opening is filled with an insulating material. The electrostatic chuck device according to claim 1, wherein the electrostatic chuck device is provided. 16. A plasma processing apparatus comprising the electrostatic chuck device according to claim 1 mounted in a chamber for performing plasma processing.

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