JP5879879B2 - Electrostatic chuck device - Google Patents

Description

  The present invention relates to an electrostatic chuck device. More specifically, the present invention is suitably used when a plate-like sample such as a semiconductor wafer is attracted and fixed by electrostatic force in a semiconductor manufacturing process, and the in-plane temperature of the suction surface of the plate-like sample is uniform The present invention relates to an electrostatic chuck device having excellent performance.

  In recent years, in semiconductor manufacturing processes, further improvement of microfabrication technology has been demanded along with higher integration and higher performance of elements. In this semiconductor manufacturing process, the etching technique is an important one of the microfabrication techniques. In recent years, the plasma etching technique capable of high-efficiency and large-area microfabrication has become the mainstream among the etching techniques. .

  This plasma etching technique is a kind of dry etching technique. A mask pattern is formed with a resist on a solid material to be processed, and this solid material is supported in a vacuum. By introducing and applying a high-frequency electric field to this reactive gas, the accelerated electrons collide with gas molecules to form a plasma state, and radicals (free radicals) and ions generated from this plasma react with the solid material. This is a technique for forming a fine pattern in a solid material by removing it as a reaction product.

On the other hand, there is a plasma CVD method as one of thin film growth techniques in which source gases are combined by the action of plasma and the obtained compound is deposited on a substrate. This method is a film forming method in which plasma discharge is performed by applying a high-frequency electric field to a gas containing source molecules, source molecules are decomposed by electrons accelerated by the plasma discharge, and the obtained compound is deposited. . Reactions that did not occur only at thermal excitation at low temperatures are also possible in the plasma because the gases in the system collide with each other and are activated to become radicals.
2. Description of the Related Art Conventionally, in a semiconductor manufacturing apparatus using plasma such as a plasma etching apparatus and a plasma CVD apparatus, an electrostatic chuck apparatus is used as an apparatus for simply mounting and fixing a wafer on a sample stage and maintaining the wafer at a desired temperature. Is used.

In such an electrostatic chuck apparatus, it is necessary to control the temperature of a plate-like sample such as a semiconductor substrate to be adsorbed. For example, an electrostatic chucking internal electrode and a plate-like or foil-like heater are connected to a semiconductor substrate. Embedded in the electrostatic chuck body, an electrostatic power source for adjusting the voltage of the internal electrode for electrostatic adsorption, a heater power source for adjusting the output voltage to the heater, and an electrostatic chuck body An electrostatic chuck device having a temperature sensor for measuring the temperature of a semiconductor substrate to be manufactured has been proposed (Patent Document 1). In this electrostatic chuck device, the temperature of the semiconductor substrate is controlled by applying a fluorescent paint to the temperature measuring unit on the back of the substrate, applying light to the fluorescent paint, and measuring the emitted fluorescence with a temperature sensor. Is possible. In this case, it is said that the temperature change of the substrate at the time of the change in the adsorption force can be prevented without applying a local stress to the substrate.
In addition, the temperature of the plate-like sample placed on the stage is urged to the temperature measurement member by a coil spring and a temperature-measuring member made of aluminum having a phosphor coated on the surface opposite to the plate-like sample. The temperature of the plate sample is controlled by measuring with a fluorescence thermometer equipped with an optical fiber and a measuring instrument that measures the temperature of the plate sample using an output signal from the fluorescence thermometer. An electric chuck has also been proposed (Patent Document 2).

JP-A-6-170670 Japanese Patent Laid-Open No. 10-48063

Incidentally, in the electrostatic chuck device of Patent Document 1 described above, since the electrostatic chuck internal electrode, the heater, and the temperature sensor are integrated with the electrostatic chuck body, the temperature of the semiconductor substrate measured by the temperature sensor. The measured value is affected by the heat conduction from the heater, and there is a problem that an error occurs in the measured temperature value. Since the error of the measured value becomes large when the temperature of the semiconductor substrate is raised and lowered, there arises a new problem that the temperature control accuracy of the semiconductor substrate is lowered when the temperature is raised and lowered.
On the other hand, in the electrostatic chuck of Patent Document 2 described above, the phosphor is applied not to the surface of the temperature measurement member on the plate-like sample side but to the surface opposite to the plate-like sample. There was a problem that a time lag occurred in temperature detection.
In addition, since the temperature measuring member with a phosphor, the coil spring, and the optical fiber are integrated, the temperature measurement value is affected by the influence of heat conduction as in the electrostatic chuck device of Patent Document 1. An error occurs, and a new problem arises that the accuracy of temperature control of the plate-like sample at the time of temperature rise and drop is lowered.

  The present invention has been made in view of the above circumstances, can reduce the temperature measurement error that occurs when measuring the temperature of a plate-like sample using a phosphor, and stabilizes the temperature of the heating element. An object of the present invention is to provide an electrostatic chuck device excellent in performance and response.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have made a static surface in which one main surface is a mounting surface on which a plate-like sample is mounted and an internal electrode for electrostatic adsorption is built-in. A chuck portion and a temperature adjusting base portion for adjusting the electrostatic chuck portion to a desired temperature, and a heating element is provided on a main surface opposite to the mounting surface of the electrostatic chuck portion, and the heating element A temperature measuring element provided with a phosphor layer on a surface of the translucent member on the heating element side, and the electrostatic chuck part and the temperature adjusting base part are provided with an insulating organic system. If the adhesive is integrated through the adhesive layer, the temperature change of the heating element can be quickly detected by the phosphor layer, and therefore the error in the temperature measurement of the heating element using the phosphor layer can be reduced. And the fact that the temperature stability and responsiveness of the heating element is improved , Which resulted in the completion of the present invention.

That is, an electrostatic chuck device according to the present invention includes 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 adsorption is built in, and the electrostatic chuck portion. A temperature adjusting base portion for adjusting the temperature to a desired temperature, a heating element is provided on a main surface opposite to the mounting surface of the electrostatic chuck portion, and a translucent member is provided on a part of the heating element. A temperature measuring element provided with a phosphor layer in contact with the surface of the heating element side, the temperature measuring element is in contact with a light-transmitting adhesive in the phosphor layer, and the heat generation via the adhesive It is bonded to a body, and the electrostatic chuck portion and the temperature adjusting base portion are bonded and integrated through an insulating organic adhesive layer.

This electrostatic chuck device is a temperature measurement in which a part of a heating element provided on the main surface opposite to the mounting surface of the electrostatic chuck part is provided with a phosphor layer on the surface of the translucent member on the heating element side. By providing the element, the temperature of the heating element is directly detected by the phosphor layer, and the heat input / output from other than the heating element is suppressed, and the temperature measurement error of the heating element by the phosphor layer is reduced. Therefore, the temperature stability and responsiveness of the heating element are improved.
Thereby, the temperature of the mounting surface of the electrostatic chuck device is quickly reached to a desired temperature, and the desired temperature is stabilized at a constant temperature.

In this electrostatic chuck device, the heat transfer coefficient between the heating element and the temperature probe is preferably 600 W / m ² K or more.
In this electrostatic chuck device, the heat transfer coefficient between the heating element and the temperature probe is 600 W / m ² K or more, so that the responsiveness between the heating element and the temperature probe is improved.

In this electrostatic chuck apparatus, the thermal conductivity of the temperature probe is preferably 5 W / mK or less.
In this electrostatic chuck device, heat dissipation of the temperature probe is suppressed by setting the thermal conductivity of the temperature probe to 5 W / mK or less.

In this electrostatic chuck device, the temperature measuring element is provided with temperature measuring means for irradiating the phosphor layer with excitation light and measuring the temperature of the heating element based on the fluorescence emitted from the phosphor layer. It is preferable.
In this electrostatic chuck device, the temperature measuring element is provided with temperature measuring means for irradiating the phosphor layer with excitation light and measuring the temperature of the heating element based on the fluorescence emitted from the phosphor layer. Even if the fluorescence emitted from the body layer passes through the temperature gauge and the light intensity decreases, this decrease in the light intensity does not cause a temperature measurement error.

In this electrostatic chuck device, the heat transfer coefficient between the heating element and the phosphor layer is at least five times the heat transfer coefficient between the temperature adjusting base and the phosphor layer, and The heat transfer coefficient between the temperature measuring element and the temperature measuring means is preferably 1/5 or less of the heat transfer coefficient between the heating element and the temperature measuring element.
In this electrostatic chuck device, the heat transfer coefficient between the heating element and the phosphor layer is at least five times the heat transfer coefficient between the temperature adjusting base and the phosphor layer, and the temperature probe and temperature By setting the heat transfer coefficient between the heating means to 1/5 or less of the heat transfer coefficient between the heating element and the temperature probe, the heat generated from the heating element flows to the temperature adjusting base. To prevent.

In the electrostatic chuck device, it is preferable that a thickness of the translucent member in a direction perpendicular to the phosphor layer is 2 mm or less.
In this electrostatic chuck device, the thickness of the translucent member in the direction perpendicular to the phosphor layer is set to 2 mm or less, thereby reducing the heat capacity of the translucent member and suppressing heat dissipation in the translucent member. To do.

In this electrostatic chuck device, it is preferable that the translucent member is quartz glass.
In this electrostatic chuck device, since the translucent member is made of quartz glass, in this translucent member, excitation light for exciting the phosphor layer and transmission loss of fluorescence emitted from the phosphor layer are small. Therefore, the temperature measurement error of the heating element due to the phosphor layer is further reduced. Therefore, the temperature stability and responsiveness of the heating element are further improved.

  According to the electrostatic chuck device of the present invention, a heating element is provided on the main surface opposite to the mounting surface of the electrostatic chuck portion, and fluorescent light is provided on a surface of the light transmitting member on the heating element side. A temperature measuring element having a body layer is provided, and the electrostatic chuck portion and the temperature adjusting base portion are bonded and integrated through an insulating organic adhesive layer. Is directly detected, and by suppressing the heat input / output from other than the heating element, the temperature measurement error of the heating element by the phosphor layer can be reduced. Therefore, the stability and responsiveness of the temperature of the heating element can be improved, and the temperature of the mounting surface of the electrostatic chuck device can be quickly reached the desired temperature, and the desired temperature can be kept constant. Can be stabilized.

In this electrostatic chuck device, if the heat transfer coefficient between the heating element and the temperature measuring element is 600 W / m ² K or more, the responsiveness between the heating element and the temperature measuring element can be improved.
Moreover, if the thermal conductivity of the temperature probe is 5 W / mK or less, heat dissipation in the temperature probe can be suppressed.
Further, if the temperature probe is provided with temperature measuring means for irradiating the phosphor layer with excitation light and measuring the temperature of the heating element based on the fluorescence emitted from the phosphor layer, Even when the light intensity decreases when the emitted fluorescent light passes through the temperature probe, this decrease in light intensity does not cause a temperature measurement error.

In this electrostatic chuck device, the heat transfer coefficient between the heating element and the phosphor layer is at least five times the heat transfer coefficient between the temperature adjusting base and the phosphor layer, and the temperature probe and temperature If the heat transfer coefficient with the measuring means is set to 1/5 or less of the heat transfer coefficient between the heating element and the temperature probe, the heat generated from the heating element is prevented from flowing into the temperature adjusting base. can do.
Further, if the thickness in the direction perpendicular to the phosphor layer in the translucent member is 2 mm or less, the heat capacity of the translucent member can be reduced, and heat dissipation in the translucent member can be suppressed. it can.
Further, if the translucent member is made of quartz glass, the transmission loss of excitation light for exciting the phosphor layer and the fluorescence emitted from the phosphor layer can be reduced, and therefore the temperature of the heating element by the phosphor layer can be reduced. The measurement error can be further reduced, and the temperature stability and responsiveness of the heating element can be further improved.

It is sectional drawing which shows the electrostatic chuck apparatus of one Embodiment of this invention. It is a figure which shows the measurement result of the temperature of the mounting surface in the temperature rising process of the Example of this invention, and each electrostatic chuck apparatus of a comparative example.

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.

  FIG. 1 is a cross-sectional view showing an electrostatic chuck device according to an embodiment of the present invention. The electrostatic chuck device 1 has a top surface (one main surface) on which a plate-like sample W such as a semiconductor wafer is placed. A disc-shaped electrostatic chuck portion 2 as a mounting surface, a thick disc-shaped temperature adjusting base portion 3 for adjusting the electrostatic chuck portion 2 to a desired temperature, and an electrostatic chuck portion 2 A thin plate-like heater element (heating element) 4 provided on the lower surface (main surface opposite to the mounting surface), a temperature measuring element 5 provided on a part of the heater element 4, and the temperature measuring element 5 The liquid adhesive that bonds and integrates the temperature measuring unit (temperature measuring means) 6 that measures the temperature of the heater element 4 based on the light emitted from the electrostatic chuck unit 2 and the temperature adjusting base unit 3 is cured. And an insulating organic adhesive layer 7.

The electrostatic chuck unit 2 is integrated with a mounting plate 11 whose upper surface is a mounting surface 11 a on which a plate-like sample W such as a semiconductor wafer is mounted, and a mounting plate 11 that is integrated with the lower surface of the mounting plate 11. A support plate 12 for supporting the electrostatic chuck, an electrostatic adsorption internal electrode 13 provided between the mounting plate 11 and the support plate 12, and an electrostatic adsorption provided around the electrostatic adsorption internal electrode 13 An insulating material layer 14 that insulates the internal electrode 13 and a power supply terminal 15 that is provided so as to penetrate the support plate 12 and that applies a DC voltage to the internal electrode 13 for electrostatic adsorption.
A plurality of projections 16 having a diameter smaller than the thickness of the plate-like sample are formed on the placement surface of the placement plate 11, and the plate-like sample W placed by these projections 16 is supported. It has become.

The mounting plate 11 and the support plate 12 are disk-like ones with the same shape of the superimposed surfaces, and are an 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, etc., which are made of ceramics having mechanical strength and having durability and insulation against corrosive gas and its plasma.

The electrostatic chucking internal electrode 13 is used as an electrostatic chuck electrode for generating a charge and fixing the plate-like sample W to the mounting surface 11a of the mounting plate 11 by electrostatic chucking force. The shape and size are appropriately adjusted depending on the application.
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 It is made of conductive ceramics such as a sintered body, or a high melting point metal such as tungsten (W), tantalum (Ta), molybdenum (Mo), titanium (Ti) or the like.

The thickness of the electrostatic attraction internal electrode 13 is not particularly limited, but is preferably 1 μm or more and 50 μm or less, and particularly preferably 5 μm or more and 20 μm or less. The reason is that when the thickness is less than 1 μm, the sheet resistance becomes too large to ensure sufficient conductivity, and when the thickness exceeds 50 μm, the electrostatic adsorption internal electrode 13 and the mounting electrode are placed. This is because, due to the difference in thermal expansion coefficient between the plate 11 and the support plate 12, there is a risk that cracks may occur at the bonding interface between the electrostatic adsorption internal electrode 13 and the mounting plate 11 and the support plate 12. .
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 electrostatic adsorption internal electrode 13 to protect the electrostatic adsorption internal electrode 13 from corrosive gas and its plasma, and at the boundary between the mounting plate 11 and the support plate 12, that is, The outer peripheral region outside the electrostatic attraction internal electrode 13 is joined and integrated, and is composed of the same composition or the main component of the same material as the material constituting the mounting plate 11 and the support plate 12 with the same insulating material. .

The power supply terminal 15 is a rod-like body provided to apply a DC voltage to the electrostatic adsorption internal electrode 13 so as to penetrate the support plate 12, the organic adhesive layer 7, and the temperature adjustment base 3. Is provided.
The material of the power supply terminal 15 may be any conductive material having excellent heat resistance, and is not particularly limited. However, the thermal expansion coefficient is the thermal expansion of the electrostatic adsorption internal electrode 13 and the support plate 12. It is preferable to approximate the coefficient. For example, conductive ceramics having the same composition as or similar to that of the internal electrode 13 for electrostatic adsorption, or tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb) A metal material such as Kovar alloy is preferably used.

The power feeding terminal 15 is insulated from the temperature adjusting base 3 by an insulator (not shown).
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 thickness of the electrostatic chuck portion 2, that is, the total thickness of the mounting plate 11, the support plate 12, the electrostatic adsorption internal electrode 13, and the insulating material layer 14 is preferably 0.3 mm or more and 2 mm or less. The reason is that if the thickness of the electrostatic chuck portion 2 is less than 0.3 mm, the mechanical strength of the electrostatic chuck portion 2 cannot be ensured, while if the thickness of the electrostatic chuck portion 2 exceeds 2 mm. In addition, the electrostatic attraction force is reduced, and the heat capacity of the electrostatic chuck unit 2 including the mounting plate 11 and the support plate 12 becomes too large. As a result, the thermal response of the plate-shaped sample W to be mounted This is because it is difficult to maintain the in-plane temperature distribution of the plate-like sample W uniformly due to an increase in the lateral heat transfer of the electrostatic chuck portion 2.

The temperature adjusting base unit 3 is provided below the electrostatic chuck unit 2 and controls the mounting surface of the mounting plate 11 to a desired temperature by adjusting the temperature of the electrostatic chuck unit 2. In addition, it also has a high frequency generating electrode.
A flow path 21 for circulating a cooling medium such as water or an organic solvent is formed in the temperature adjusting base portion 3, and the temperature of the plate-like sample W placed on the placement plate 11 is desired. The temperature can be maintained. Further, the temperature adjusting base portion 3 is formed with a through hole 22 for accommodating the temperature measuring element 5 attached to the heater element 4.

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 plasma is anodized or an insulating film such as alumina is formed.

  Then, on the surface of the temperature adjusting base 3 on the electrostatic chuck 2 side, a sheet-like or film-like adhesive layer 23 having heat resistance and insulation, excluding the region where the temperature probe 5 is located. A sheet-like or film-like insulation made of a polyimide resin, a silicone resin, an epoxy resin, an acrylic resin, or the like having the same planar shape as the adhesive layer 23 is adhered on the adhesive layer 23. A material layer 24 is adhered.

The heater element 4 has a pattern in which a narrow band-shaped metal material is meandered, and power supply terminals (not shown) are connected to both ends of the heater element 4. (Not shown) is insulated from the temperature adjusting base 3 and is connected to an external power supply power source (not shown).
In this heater element 4, by controlling the applied voltage, the in-plane temperature distribution of the plate-like sample W fixed on the protrusion 16 of the mounting plate 11 by electrostatic adsorption is accurately controlled. Yes.

The heater element 4 has a constant thickness of 0.2 mm or less, preferably 0.1 mm or less, such as a non-magnetic metal thin plate, such as a titanium (Ti) thin plate, a tungsten (W) thin plate, a molybdenum (Mo) thin plate, or the like. Is formed by etching into a desired heater pattern by photolithography.
Here, the reason why the thickness of the heater element 4 is set to 0.2 mm or less is that when the thickness exceeds 0.2 mm, the pattern shape of the heater element 4 is reflected as the temperature distribution of the plate-like sample W. This is because it becomes difficult to maintain the in-plane temperature in a desired temperature pattern.

Further, by forming the heater element 4 with a non-magnetic metal thin plate having a constant thickness of 0.2 mm or less, even when the electrostatic chuck device 1 is used in a high-frequency atmosphere, the heater element 4 has a high-frequency. Therefore, it is easy to maintain the in-plane temperature of the plate-like sample W at a desired constant temperature or a constant temperature pattern.
Further, by forming the heater element 4 using a non-magnetic metal thin plate having a constant thickness, the thickness of the heater element 4 becomes constant over the entire heating surface, and the amount of heat generation becomes constant over the entire heating surface. The temperature distribution on the mounting surface of the chuck unit 2 can be made uniform.

The heater element 4 is bonded and fixed to the lower surface 2b of the electrostatic chuck portion 2 by an adhesive layer 25 made of a sheet-like or film-like silicon resin or acrylic resin having uniform heat resistance and insulation. .
The in-plane thickness variation of the adhesive layer 25 is preferably within 10 μm.
Here, if the in-plane thickness variation of the adhesive layer 25 exceeds 10 μm, the in-plane spacing between the heater element 4 and the lower surface 2b of the electrostatic chuck portion 2 will exceed 10 μm. This is not preferable because it adversely affects the temperature control of the surface of the plate-like sample W placed on the placement surface 11a of the chuck portion 2.

The temperature measuring element 5 is transparent to light in the wavelength range of 600 nm to 1300 nm. For example, the temperature measuring element 5 is fluorescent on the surface of the cubic or rectangular parallelepiped quartz glass (translucent member) 31 on the heater element 4 side. A body layer 32 is formed, and the phosphor layer 32 of the temperature probe 5 is attached to the heater element 4 via a silicon resin adhesive 33 having translucency with respect to light in the wavelength range of 600 nm to 1300 nm. Bonded and fixed.
The quartz glass 31 preferably has a thickness in the direction perpendicular to the phosphor layer 32 of 2 mm or less. By setting the thickness of the quartz glass 31 to 2 mm or less, the heat capacity of the quartz glass 31 itself can be reduced, and heat dissipation in the quartz glass 31 can be suppressed.

  The phosphor layer 32 has a thickness of 100 μm or more and 300 μm or less. As the phosphor constituting the phosphor layer 32, the phosphor layer 32 generates fluorescence in response to heat generated from the heater element 4, and deteriorates due to the heat generation. And the like are not particularly limited, and can be selected from a wide variety of fluorescent materials depending on applications and purposes. For example, a fluorescent material to which a rare earth element having an energy level suitable for light emission is added, a semiconductor material such as AlGaAs, a metal oxide such as magnesium oxide, or a mineral such as ruby or sapphire can be appropriately selected and used.

The heat transfer coefficient between the temperature gauge 5 and the heater element 4 is preferably 600 W / m ² K or more, and more preferably 1200 W / m ² K or more.
Thus, if the heat transfer coefficient between the temperature measuring element 5 and the heater element 4 is 600 W / m ² K or more, the responsiveness between the temperature measuring element 5 and the heater element 4 can be improved. .

The thermal conductivity of the temperature probe 5 is preferably 5 W / mK or less, more preferably 2.0 W / mK or less.
Thus, the heat dissipation in the temperature measuring element 5 can be suppressed by setting the thermal conductivity of the temperature measuring element 5 to 5 W / mK or less.

  The temperature measuring unit 6 is provided below the temperature probe 5 and measures the temperature of the heater element 4. The temperature measuring unit 6 emits from the phosphor layer 32 and the excitation unit 41 that irradiates the phosphor layer 32 with excitation light. And a control unit 43 that controls the excitation unit 41 and the fluorescence detection unit 42 and calculates the temperature of the heater element 4 based on the fluorescence detected by the fluorescence detection unit 42. Yes.

The excitation unit 41 includes a light emitting element such as a light emitting diode (LED) or a laser diode (LD), a drive circuit that drives the light emitting element, and a light modulation unit that modulates light emitted from the light emitting element to a desired wavelength. I have.
The excitation unit 41 irradiates the phosphor layer 32 with controlled excitation light based on the signal from the control unit 43.

The fluorescence detection unit 42 converts a light receiving element such as a photodiode (PD) that detects fluorescence emitted from the phosphor layer 32, a drive circuit that drives the light receiving element, and light output from the light receiving element into an electrical signal. And a photoelectric conversion unit.
In the fluorescence detection unit 42, fluorescence emitted from the phosphor layer 32 is detected by the light receiving element, and the detected fluorescence is converted into an electric signal by photoelectric conversion.
Further, the control unit 43 calculates the temperature of the heater element 4 based on the electrical signal from the fluorescence detection unit 42.

In the temperature measuring element 5 and the temperature measuring unit 6, the heat transfer coefficient between the phosphor layer 32 and the heater element 4 is five times or more than the heat transfer coefficient between the temperature adjusting base unit 3 and the phosphor layer 32. Is preferable, and more preferably 10 times or more.
The heat transfer coefficient between the temperature measuring element 5 and the temperature measuring unit 6 is preferably 1/5 or less of the heat transfer coefficient between the heater element 4 and the temperature measuring element 5, more preferably 1/10 or less.
Here, the reason why the heat transfer coefficient between the phosphor layer 32 and the heater element 4 and the heat transfer coefficient between the temperature measuring element 5 and the temperature measuring unit 6 are set in the above range is generated from the heater element 4. This is because heat can be prevented from flowing into the temperature adjusting base portion 3.

  The organic adhesive layer 7 is an insulating and organic adhesive layer formed by curing a liquid organic adhesive, and is provided on the electrostatic chuck portion 2 having the heater element 4 and the temperature adjusting base portion 3. An insulating and organic adhesive in which a sheet-like or film-like insulating layer 52 bonded and fixed to each other via a sheet-like or film-like adhesive layer 51 is bonded and integrated in a state of facing each other. Is a layer.

The thickness of the organic adhesive layer 7 is preferably 400 μm or less, more preferably 200 μm or less.
Here, the reason why the thickness of the organic adhesive layer 7 was set to 400 μm or less was that when the thickness exceeded 400 μm, the change in thickness due to curing shrinkage of the liquid organic adhesive was too large, and thus obtained. Voids due to curing shrinkage of the organic adhesive layer 7 are generated, the adhesive strength is lowered, and the heat transfer coefficient of the adhesive layer is lowered. As a result, the temperature rising performance and cooling performance of the electrostatic chuck portion are reduced. It is because it falls.

As the insulating and organic adhesive constituting the organic adhesive layer 7, an acrylic adhesive is preferable. As the acrylic adhesive, acrylic acid and its ester, methacrylic acid and its ester, acrylamide, and acrylonitrile are used. , And polymers or copolymers thereof.
Among these, in particular, polyacrylic acid esters such as polymethyl acrylate, polymethacrylic acid esters such as polymethyl methacrylate, and the like are preferably used.

Next, a temperature control method for the heater element 4 will be described.
First, a predetermined power is applied to the heater element 4 by a power supply terminal (not shown) to generate heat, and the heater element 4 is set to a predetermined temperature. On the other hand, since the phosphor layer 32 is bonded and fixed to the heater element 4 via the silicon resin adhesive 33, it is quickly heated by the heat generated from the heater element 4 and has the same temperature as the heater element 4.

Next, excitation light whose intensity is modulated is irradiated from the excitation unit 41 of the temperature measurement unit 6 to the phosphor layer 32. At this time, since the phosphor layer 32 is at the same temperature as the heater element 4, fluorescence corresponding to the temperature of the heater element 4 is generated by receiving excitation light.
The fluorescence detection unit 42 detects this fluorescence and photoelectrically converts the wavelength or intensity of the fluorescence to output as a wavelength signal or intensity-time signal of the fluorescence.

  Based on the fluorescence wavelength signal or intensity-time signal output from the fluorescence detection unit 42, the control unit 43 calculates the fluorescence wavelength shift magnitude or intensity decay time constant, and the wavelength shift magnitude or intensity. The temperature of the heater element 4 is accurately calculated from the decay time constant of. Next, a temperature difference between the calculated temperature of the heater element 4 and a preset temperature of the heater element 4 is calculated, and an electric signal corresponding to the temperature difference is supplied to a power supply power source (not shown) of the heater element 4. send.

In this power supply power source, the power supplied to the heater element 4 via a power supply terminal (not shown) is adjusted based on an electrical signal corresponding to this temperature difference, and the temperature of the heater element 4 is controlled to a predetermined temperature. To do.
As described above, the temperature of the heater element 4 can be accurately controlled.

Next, a method for manufacturing the electrostatic chuck device 1 will be described.
First, the plate-shaped mounting plate 11 and the support plate 12 are made of ceramics such as an aluminum oxide-silicon carbide (Al ₂ O ₃ —SiC) composite sintered body. For example, when the mounting plate 11 and the support plate 12 are made of an aluminum oxide-silicon carbide (Al ₂ O ₃ —SiC) composite sintered body, a mixed powder containing silicon carbide powder and aluminum oxide powder is formed in a desired shape. Then, the mounting plate 11 and the support plate 12 can be obtained by firing for a predetermined time in a non-oxidizing atmosphere, preferably an inert atmosphere, for example, at a temperature of 1600 ° C. to 2000 ° C.

Next, a plurality of fixing holes for fitting and holding the power supply terminals 15 are formed in the support plate 12.
Next, the power supply terminal 15 is fabricated so as to have a size and 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 it can be cited. It is done.
The conductive ceramic powder is preferably a conductive ceramic powder made of the same material as the electrostatic adsorption internal electrode 13.
In addition, when the power feeding terminal 15 is made of metal, a method of using a refractory metal and forming by a metal working method such as a grinding method or powder metallurgy can be used.

Next, electrostatic adsorption in which a conductive material such as conductive ceramic powder is dispersed in an organic solvent so as to come into contact with the power supply terminal 15 in a predetermined region on the surface of the support plate 12 in which the power supply terminal 15 is fitted. The internal electrode forming coating solution is applied and dried to form an electrostatic adsorption internal electrode forming layer.
As this coating method, a screen printing method is desirable in that it can be applied to a uniform thickness. Other methods include forming a thin film of the above-mentioned refractory metal by vapor deposition or sputtering, or arranging an electroconductive ceramic or refractory metal thin plate to provide an internal electrode for electrostatic adsorption. There is a method of forming a formation layer.

  Further, in order to improve insulation, corrosion resistance, and plasma resistance in a region other than the region where the internal electrode forming layer for electrostatic attraction is formed on the support plate 12, the same as the mounting plate 11 and the support plate 12. An insulating material layer including a powder material having the same composition or main component is formed. For example, the insulating material layer is formed by applying a coating liquid in which an insulating material powder 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, It can be formed by drying.

Next, the mounting plate 11 is overlaid on the electrostatic adsorption internal electrode forming layer and the insulating material layer on the support plate 12, and these are then integrated by hot pressing under high temperature and high pressure. The atmosphere in this hot press is preferably a vacuum or an inert atmosphere such as Ar, He, N ₂ or the like. The pressure is preferably 5 to 10 MPa, and the temperature is preferably 1600 ° C to 1850 ° C.

By this hot pressing, the internal electrode forming layer for electrostatic adsorption is fired to become the internal electrode 13 for electrostatic adsorption made of a conductive composite sintered body. At the same time, the support plate 12 and the mounting plate 11 are joined and integrated through the insulating material layer 14.
In addition, the power supply terminal 15 is refired by hot pressing under high temperature and high pressure, and is closely fixed to the fixing hole of the support plate 12. Then, the upper and lower surfaces, outer periphery, gas holes and the like of these joined bodies are machined.

  Next, a heat-resistant and insulating sheet-like or film-like silicon resin or acrylic resin is adhered to the lower surface of the support plate 12 (the main surface opposite to the placement surface of the placement plate 11), and the adhesive layer And Next, a non-magnetic metal thin plate such as a titanium (Ti) thin plate, a tungsten (W) thin plate, a molybdenum (Mo) thin plate or the like is attached onto the adhesive layer, and the thin plate is bonded to a desired layer by photolithography. Etching is performed on the heater pattern, and the adhesive layer is further processed into the same shape to obtain the heater element 4 and the adhesive layer 25 having a desired heater pattern.

Next, the quartz glass is machined into a cubic shape or a rectangular parallelepiped shape, and a fluorescent paint in which a fluorescent material is dispersed in an organic solvent containing a binder is applied to one main surface of the obtained quartz glass 31 having a predetermined shape, followed by drying. Curing to form the phosphor layer 32. Thereby, the temperature measuring element 5 in which the phosphor layer 32 is formed on one main surface of the quartz glass 31 can be manufactured.
Next, a silicon resin adhesive is applied onto the phosphor layer 32 of the temperature probe 5, and the silicon resin adhesive is brought into contact with the heater element 4, whereby the phosphor layer 32 of the temperature probe 5 is made to contact. It is placed on the heater element 4 via a silicon resin adhesive, and then the silicon resin adhesive is cured, and the phosphor layer 32 is bonded and fixed to the heater element 4 via the silicon resin adhesive 23. To do.
By the above, the electrostatic chuck part 2 with the heater element 4 and the temperature measuring element 5 can be produced.

On the other hand, a metal material made of aluminum (Al), aluminum alloy, copper (Cu), copper alloy, stainless steel (SUS), etc. is machined, and a cooling medium such as water or an organic solvent is placed inside the metal material. A circulation passage 21 and a through hole 22 for accommodating the temperature measuring element 5 are formed, and a fixing hole for fitting and holding the power supply terminal 15 and an insulator (not shown) is formed to adjust the temperature. The base portion 3 is used.
It is preferable that at least the surface exposed to the plasma of the temperature adjusting base portion 3 is subjected to alumite treatment or an insulating film such as alumina is formed.

Next, the surface on the electrostatic chuck portion 2 side of the temperature adjusting base portion 3 is degreased and washed using, for example, acetone, and a sheet-like or film-like adhesive having heat resistance and insulating properties is adhered to a predetermined position on this surface. The agent layer 23 is stuck.
Next, a sheet-like or film-like resin made of polyimide resin, silicone resin, epoxy resin, acrylic resin or the like having the same planar shape as that of the adhesive layer 23 is stuck on the adhesive layer 23. Insulating material layer 24.

Next, an insulating and organic adhesive such as an acrylic adhesive is applied on the insulating material layer 24. The application amount of this insulating and organic adhesive is such that the electrostatic chuck part 2 and the temperature adjusting base part 3 can be joined and integrated in a state where a predetermined interval is maintained by a spacer (not shown). Within a predetermined range.
Examples of the method for applying the adhesive include manual application using a spatula and the like, as well as a bar coating method and a screen printing method.

After the application, the heater element 4 and the temperature measuring element 5 of the electrostatic chuck part 2 and the insulating and organic adhesive on the temperature adjusting base part 3 are made to face each other, and these electrostatic chuck part 2 and the temperature adjusting part The base portion 3 is overlapped with an insulating and organic adhesive.
At this time, the power supply terminal 15 and the insulator (not shown) are inserted and fitted into the power supply terminal receiving hole (not shown) drilled in the temperature adjusting base portion 3, and at the same time, the temperature measuring element 5 is moved to the temperature. It inserts in the through-hole 22 formed in the base part 3 for adjustment.
Next, the space between the lower surface of the electrostatic chuck portion 2 and the insulating material layer 24 on the temperature adjusting base portion 3 is dropped until the thickness of the spacer (not shown) is reached, and the extruded excess adhesive is removed.

  As described above, the electrostatic chuck portion 2 with the heater element 4 and the temperature probe 5 and the temperature adjusting base portion 3 having the insulating material layer 24 and the adhesive layer 23 are joined and integrated through the organic adhesive layer 7. Thus, the electrostatic chuck device 1 of this embodiment is obtained.

  In the electrostatic chuck device 1 thus obtained, the heater element 4 is provided on the surface 2 b opposite to the mounting surface 11 of the electrostatic chuck portion 2, and the quartz glass 31 is formed on a part of the heater element 4. The temperature measuring element 5 having the phosphor layer 32 formed on the surface on the heater element 4 side is bonded and fixed via a silicon resin adhesive 33, and the electrostatic chuck part 2 and the temperature adjusting base part 3 are fixed. Are bonded and integrated through the insulating organic adhesive layer 7, so that the temperature of the heater element 4 is directly detected by the phosphor layer 32, and the phosphor layer 32 from other than the heater element 4 is detected. By suppressing the entry and exit of heat, the temperature measurement error of the heater element 4 by the phosphor layer 32 can be reduced. Therefore, the stability and responsiveness of the temperature of the heater element 4 can be improved. Further, the temperature of the mounting surface 11 of the electrostatic chuck device 1 can be quickly reached the desired temperature, and the desired temperature can be set. It can be stabilized at a constant temperature.

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

"Example"
(Production of electrostatic chuck device)
An electrostatic chuck portion 2 in which an internal electrode 13 for electrostatic attraction having a thickness of 20 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 7% by mass of silicon carbide, and has a disk shape with a diameter of 310 mm and a thickness of 4 mm.

Similarly to the mounting plate 11, the support plate 12 is an aluminum oxide-silicon carbide composite sintered body containing 7% by mass of silicon carbide, and has a disk shape with a diameter of 310 mm and a thickness of 4 mm.
The mounting plate 11 and the support plate 12 were joined and integrated to obtain the electrostatic chuck portion 2.

  The joined body is machined to have a diameter of 298 mm and a thickness of 4 mm, and then the electrostatic adsorption surface of the mounting plate 11 is formed into an uneven surface by forming a large number of protrusions 16 having a height of 30 μm. The top surface of the projection 16 is used as a holding surface for the plate-like sample W so that the cooling gas can flow in a groove formed between the concave portion and the plate-like sample W electrostatically adsorbed.

  Next, a silicon resin sheet is attached to the lower surface of the support plate 12, and a titanium (Ti) thin plate having a thickness of 0.1 mm is brought into close contact with the silicon resin sheet. The titanium (Ti) thin plate is bonded to a desired shape by photolithography. Etching was performed on the heater pattern, and the silicon resin sheet was further processed into the same shape to obtain the heater element 4 and the adhesive layer 25 having a desired heater pattern.

Next, a fluorescent paint was applied to one main surface of the quartz glass 31 machined into a cubic shape, dried and cured, and a phosphor layer 32 was formed. Thereby, the temperature measuring element 5 in which the phosphor layer 32 was formed on one main surface of the quartz glass 31 was obtained.
Next, a silicon resin adhesive is applied onto the phosphor layer 32 of the temperature probe 5, and the phosphor layer 32 of the temperature probe 5 is placed on the heater element 4 via the silicon resin adhesive. The silicon resin adhesive was cured, and the phosphor layer 32 was adhered and fixed to the heater element 4 via the silicon resin adhesive 23.
The electrostatic chuck part 2 with the heater element 4 and the temperature measuring element 5 of the Example was obtained by the above.

On the other hand, an aluminum temperature adjusting base portion 3 having a diameter of 340 mm and a height of 30 mm was manufactured by machining. A through-hole 22 for accommodating the flow path 21 for circulating the refrigerant and the temperature probe 5 is formed in the temperature adjusting base portion 3.
A square spacer having a width of 2 mm, a length of 2 mm, and a height of 100 μm was prepared by laminating a polyimide sheet (75 μm) and an epoxy sheet adhesive (25 μm).

Next, the surface of the temperature adjusting base portion 3 on the electrostatic chuck portion 2 side is degreased and washed with acetone, and a sheet-like silicon resin is adhered to a predetermined position on this surface to form an adhesive layer 23. .
Next, a sheet-like polyimide resin was stuck on the adhesive layer 23 to form an insulating material layer 24.
Next, an acrylic adhesive is applied on the insulating material layer 24 by screen printing, and then the heater element 4 and the temperature measuring element 5 of the electrostatic chuck portion 2 and the insulating material layer of the temperature adjusting base portion 3 are used. 24 were opposed to each other and overlapped with an acrylic adhesive.
Next, the space between the lower surface of the electrostatic chuck part 2 and the insulating material layer 24 on the temperature adjusting base part 3 is dropped until the thickness of the spacer (not shown) is reached, and the extruded excess adhesive is removed, The electrostatic chuck device of Example 1 was produced.

"Comparative example"
(Production of electrostatic chuck device)
The static measurement of the comparative example is the same as that of the comparative example except that the temperature measuring element 5 provided on the heater element 4 of the electrostatic chuck part 2 is changed to one in which a phosphor is applied to the surface of the aluminum temperature measuring part. An electric chuck device was produced.

"Evaluation of electrostatic chuck device"
The temperature in the steady state of the mounting surface on which the plate-like sample is placed in each of the electrostatic chuck devices of the above Examples and Comparative Examples was examined, and the temperature change in the temperature rising / falling process was examined and evaluated. Here, the temperature of the mounting surface on which the plate-like sample is mounted was continuously measured by a thermocouple and a thermograph installed on the mounting surface.

FIG. 2 is a diagram showing the result of measuring the temperature of the mounting surface with a thermocouple in the temperature rising process of each of the electrostatic chuck devices of the example and the comparative example.
According to these results, it was found that in the example, the temperature was gently raised so as to substantially follow the programmed temperature rise pattern, and then the maximum holding temperature of 40 ° C. was well maintained.
On the other hand, in the comparative example, the temperature gradient increases as the temperature rises, overshoots exceeding the maximum holding temperature of the temperature rising pattern, rises to 44 ° C. higher than 40 ° C. of the temperature rising pattern, and then rises in temperature rising pattern. The maximum holding temperature was lowered to 40 ° C., and then maintained at 40 ° C.

As described above, the electrostatic chuck device of the example has a small variation in the temperature of the heater element 4 as compared with the electrostatic chuck device of the comparative example, and the temperature of the mounting surface is gently along the temperature rising pattern. It was found that the maximum holding temperature of 40 ° C. was satisfactorily maintained without overshooting.
Therefore, it was found that the electrostatic chuck device of the example can reduce the error in temperature measurement of the heater element 4 by the phosphor layer 32. Further, in the temperature raising process, the temperature of the temperature measuring element 5 rises prior to the temperature of the mounting surface on which the plate-like sample is mounted. It was found that the temperature overshoot at the surface could be avoided.
From the above, it has been found that the electrostatic chuck device of the example has improved temperature stability and responsiveness of the heater element 4 compared to the electrostatic chuck device of the comparative example.

DESCRIPTION OF SYMBOLS 1 Electrostatic chuck apparatus 2 Electrostatic chuck part 3 Base part for temperature adjustment 4 Heater element (heating element)
5 Temperature measuring element 6 Temperature measuring part (temperature measuring means)
7 Insulating Organic Adhesive Layer 11 Mounting Plate 11a Mounting Surface 12 Support Plate 13 Electrostatic Suction Internal Electrode 14 Insulating Material Layer 15 Power Feeding Terminal 16 Protrusion 21 Channel 22 Through Hole 23 Adhesive Layer 24 Insulation Material layer 25 Adhesive layer 31 Quartz glass (translucent member)
32 Phosphor Layer 33 Silicone Resin Adhesive 41 Excitation Unit 42 Fluorescence Detection Unit 43 Control Unit W Plate Sample

Claims (7)

An electrostatic chuck portion having a main surface as a mounting surface on which a plate-like sample is placed and an internal electrode for electrostatic adsorption is built in, and a temperature adjustment base for adjusting the electrostatic chuck portion to a desired temperature With
A temperature measurement is provided in which a heating element is provided on a main surface opposite to the placement surface of the electrostatic chuck portion, and a phosphor layer that is in contact with the heating element side surface of the translucent member is provided on a part of the heating element. Set up a child,
The temperature measuring element is in contact with an adhesive having translucency in the phosphor layer, and is bonded to the heating element via the adhesive,
The electrostatic chuck device, wherein the electrostatic chuck portion and the temperature adjusting base portion are bonded and integrated through an insulating organic adhesive layer. The electrostatic chuck apparatus according to claim 1, wherein a heat transfer coefficient between the heating element and the temperature probe is 600 W / m ² K or more.   The electrostatic chuck apparatus according to claim 1, wherein the thermal conductivity of the temperature probe is 5 W / mK or less.   The temperature measuring element is provided with temperature measuring means for irradiating the phosphor layer with excitation light and measuring the temperature of the heating element based on fluorescence emitted from the phosphor layer. The electrostatic chuck device according to any one of 1 to 3.   The heat transfer coefficient between the heating element and the phosphor layer is not less than five times the heat transfer coefficient between the temperature adjusting base and the phosphor layer, and the temperature measuring element and the phosphor layer 5. The electrostatic chuck device according to claim 4, wherein a heat transfer coefficient between the temperature measuring means and the heat transfer coefficient between the heating element and the temperature measuring element is 1/5 or less.   6. The electrostatic chuck device according to claim 1, wherein a thickness of the translucent member in a direction perpendicular to the phosphor layer is 2 mm or less.   The electrostatic chuck apparatus according to claim 1, wherein the translucent member is quartz glass.

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