JP2001313157A - Heater device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater device that has a high efficiency and a long product life. SOLUTION: The heater comprises a mount plate 3 for an object, a support plate 2 made integrated with the mount plate, a heater element 8 held by the mount plate 3 and the support plate 2 in between, and at least a pair of electrodes of which one end is connected with the heater element 8. The mount plate 3 and the support plate 2 are made of sintered ceramics and the thermal conductivity of the sintered ceramics constituting the mount plate is made higher in thermal conductivity than the sintered ceramics constituting the support plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus disposed in a reaction chamber and used for heating an object to be heated such as a wafer and having improved thermal efficiency and product life.

[0002]

2. Description of the Related Art Conventionally, as a heating device installed in a reaction chamber and used for heating an object to be heated such as a wafer,
For example, the heater block is divided into upper and lower parts, and a heater block (hereinafter, referred to as a “mounting plate”) on which the object to be heated is placed is relatively heat-conductive such as stainless steel or iron. And the other heater block (hereinafter referred to as “support plate”) is made of ceramic,
A heating device is known which is made of a material having a lower thermal conductivity than the material constituting the placing plate, such as pottery and stone, and in which a heater element is sandwiched between the placing plate and the supporting plate. Such a heating device has high thermal efficiency because the heat generated by the heater element can be concentrated on the mounting plate to heat the mounting plate.

[0003]

However, in such a heating device, since the material such as stainless steel and iron constituting the mounting plate is inferior in plasma resistance and the like,
There is a problem that the product life as a heating device is short.
Further, in the heating device, it is difficult to make the thermal expansion coefficient of the support plate capable of reducing the amount of heat dissipated from the lower portion of the heater element equal to the thermal expansion coefficient of the mounting plate. Because a difference occurs in the expansion coefficient, the durability of the bonding interface between the support plate and the mounting plate is not sufficient,
There was also a problem that the product life of the heating device was short.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a heating device having high thermal efficiency and a long product life. Specifically, while maintaining high thermal efficiency of the heating device, it has excellent plasma resistance, improves the durability of the boundary surface due to the difference in thermal expansion coefficient between the mounting plate and the support plate, and has a long product life. The purpose is to gain.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a mounting plate for mounting an object to be heated, a supporting plate integrated with the mounting plate, A heating device comprising: a heater element sandwiched between the mounting plate and at least one pair of electrodes having one end connected to the heater element, wherein the mounting plate and the support plate are both ceramic sintered bodies. Wherein the thermal conductivity of the ceramic sintered body constituting the mounting plate is higher than the thermal conductivity of the ceramic sintered body constituting the support plate.

[0006] Here, ceramics sintered body constituting the front mounting plate and the support plate are both Y ₂ O ₃ auxiliaries and the aluminum nitride sintered body, or was a Y ₂ O ₃ and auxiliaries together It is preferable that the ceramic sintered body of the mounting plate is an aluminum nitride-based sintered body, and the Y ₂ O ₃ content of the ceramic sintered body of the support plate is larger than the Y ₂ O ₃ content of the ceramic sintered body of the support plate. At this time, it is preferable that the support plate and the mounting plate are joined and integrated by a vitreous joining layer. Further, it is preferable that the mounting plate includes an upper plate and a lower plate, and an electrode plate is sandwiched between the upper plate and the lower plate, and the electrode is connected to the electrode plate.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. However, this embodiment is specifically described for better understanding of the gist of the invention, and does not limit the content of the invention unless otherwise specified.

FIGS. 1 and 2 are cross-sectional views showing an example of the heating device of the present invention. The heating device 1 includes a mounting plate 3 on which an object to be heated is mounted, and a support plate 2 for supporting the mounting plate 3.
A groove 12 is provided on the surface of the support plate 2, and the heater element 8 is fitted into the groove 12,
One end of a heater power supply electrode 9 is connected to the heater element 8. A thermocouple 6 for measuring the temperature is connected to the mounting plate 3. The support plate 2 and the mounting plate 3 are joined and integrated by a joining layer 10.

The support plate 2 and the mounting plate 3 are made of a ceramics sintered body such as an aluminum nitride sintered body, an aluminum nitride based sintered body, a magnesium oxide sintered body, a boron nitride sintered body and the like. As the ceramic sintered body, an aluminum nitride sintered body or an aluminum nitride based sintered body, etc., has thermal conductivity, mechanical strength, durability against plasma cleaning gas such as CF ₄ , C ₂ F ₆ and C ₂ F _8. It has excellent properties and is preferably used. As the aluminum nitride-based sintered body, in order to improve sinterability and plasma resistance, Y
One containing one or more selected from ₂ O ₃ , CaO, MgO, SiC, and TiO ₂ in a total amount of about 0.1 to 10% by weight can be exemplified.

The ceramic sintered body forming the mounting plate 3 preferably has a higher thermal conductivity than the ceramic sintered body forming the support 2. With this configuration, the thermal conductivity of the mounting plate 3 becomes higher than the thermal conductivity of the support plate 2, and the heat generated by the heater element 8 can be concentrated on the mounting plate 3. The temperature of the plate 3 can be efficiently raised, the thermal efficiency of the heating device 1 can be improved, and the amount of heat dissipated from the lower portion of the heater element 8 can be easily reduced by the support plate 2. .

The ceramic sintered body forming the placing plate 3 and the support plate 2 is an aluminum nitride sintered body or an aluminum nitride based sintered body both using Y ₂ O ₃ as an auxiliary agent. It is preferable that the content of Y ₂ O ₃ in the sintered body forming the mounting plate 3 is larger than the content of Y ₂ O ₃ in the sintered body forming the support plate 2. . By doing so, the thermal conductivity of the mounting plate 3 can be easily made higher than the thermal conductivity of the support plate 2. Therefore, as described above, the heat generated by the heater element 8 can be concentrated on the mounting plate 3, and
The amount of heat dissipated from the lower part of the heater element 8 is
Can be easily reduced.

The amount of Y ₂ O ₃ added at this time is 0 to 20% by weight, preferably 0 to 20% by weight, based on the aluminum nitride sintered body or the aluminum nitride based sintered body of the mounting plate 3 and the support plate 2. By increasing or decreasing the amount within the range of 15% by weight, the thermal conductivity of the aluminum nitride sintered body or the aluminum nitride-based sintered body, that is, the thermal conductivity of the mounting plate 3 and the supporting plate 2 can be easily adjusted. it can. In addition, in the case of the aluminum nitride sintered body or the aluminum nitride-based sintered body, even if the amount of added Y ₂ O ₃ is increased or decreased, their thermal expansion coefficients are almost unchanged. Even if a heat cycle of temperature and temperature is applied, the durability of the bonding interface between the support plate 2 and the mounting plate 3 can be ensured, so that the product life of the heating device 1 can be extended. .

The support plate 2 and the mounting plate 3 are connected to the bonding layer 1
0 is integrated. This bonding layer 10 has (1)
A bonding agent containing at least two elements selected from Group 3a elements of the periodic table, aluminum, and silicon; (2) at least one element selected from group 3a elements of the periodic table, and aluminum (3) Periodic Table No. 3
a bonding agent containing at least one element selected from group a elements, (4) at least one element selected from group 3a elements of the periodic table, aluminum, silicon, and group 2a of the periodic table It is preferable that the glassy bonding layer is made of a bonding agent or the like containing at least one element selected from the elements.

The above-mentioned vitreous bonding layer, that is, the above (1) to
The oxynitride glass having the component (4) is, for example,
Since the wettability with the ceramics sintered body is good and the bonding strength is excellent, the airtightness of the bonding layer 10 can be greatly improved, and this airtightness can be ensured for a long period of time. In addition, variations in bonding strength are small, and heat resistance can be improved. The thermal expansion coefficient of the oxynitride glass containing the above components is 3 × 10 ⁻⁶ to 8 × 10 ⁻⁶ / ° C., and the thermal expansion coefficient of the aluminum nitride sintered body or the aluminum nitride based sintered body ( (3.8 × 10 ^{−4 to} 4.7 × 10 ⁻⁶ / ° C.), and the damage of the bonding layer 10 due to the thermal stress at the time of the repeated heat-up and heat-down, that is, the generation of cracks. Thus, the airtightness of the bonding layer 10 can be ensured for a long period of time. The glass softening point Tg of the oxynitride glass containing the above components is 8
It is as high as 50 to 950 ° C., and the bonding layer 10 does not deteriorate even when exposed to a high-temperature atmosphere for a long time.

The thickness of the bonding layer 10 is 5 to 180 μm.
It is desirable that When the thickness of the bonding layer 10 is less than 5 μm, the formation of fillets in the fine portions of the bonding layer 10 is insufficient, so that the airtightness of the bonding portion 10 cannot be ensured and the bonding strength is insufficient. On the other hand, if the thickness of the bonding layer 10 exceeds 180 μm, although the airtightness of the bonding layer 10 can be ensured, the bonding strength tends to decrease, and the vitreous bonding agent melted by the heat treatment at the time of bonding may cause the bonding layer 10. And the support plate 2 and the mounting plate 3 cannot be joined in parallel, and the product yield decreases,
In addition, there is a possibility that the joining operation may be hindered.

The concave groove 12 formed in the support plate 2 is shaped so as to heat the entire mounting plate 3, and is formed, for example, in a spiral shape. The heater element 8 which is fitted in the concave groove 12 and held between the mounting plate 3 and the support plate 2 via the bonding layer 10 is sintered without any additive, that is, without adding any foreign substance. Further, it is preferably formed of a silicon carbide sintered body or the like. Since such a heater element 8 is extremely high-purity and homogeneous because no additive is added, there is no local abnormal heat generation, and a part of the bonding layer 10 melts and leaks to the bonding part. Does not occur, and the airtightness of these bonding layers 10 can be firmly secured.

The sintered density of the heater element 8 is desirably 2.8 g / cm ³ or more. With such a heater element 8, the bonding layer 10
In addition, even when a leak occurs and the airtightness is impaired, there is no possibility that the additive, that is, the impurity from the heater element 8 evaporates, and the inside of the reaction chamber is not contaminated. Further, since the heater element 8 is excellent in high-temperature strength, there is no deformation or disconnection of the heater element 8 due to thermal shock.

The electric resistance of the heater element 8 at room temperature is preferably 0.1 Ωcm or less.
With such a heater element 8, it is not necessary to make the wire thinner and thinner because it has a low electric resistivity, and it is possible to make the heater element 8 large enough to have sufficient strength. Absent.

Such a heater element 8 is fitted in the concave groove 12 of the support plate 2. At this time, since there is a gap (not shown) between the heater element 8 and the lower plate 3a,
Thermal stress caused by a difference in thermal expansion coefficient between the bonding interface 10 between the support plate 2 and the lower plate 3 a, the heater element 8 and the support plate 2, and between the heater element 8 and the mounting plate 3. This does not occur, and the durability of the bonding interface 10 is dramatically improved. When the heater element 8 is energized, the mounting plate 3 can be maintained at a predetermined temperature.

The mounting plate 3 is, for example, a lower plate 3 having a concave groove 11 formed on the upper surface as shown in FIG.
a, the electrode plate 4 loaded in the groove 11, and the lower plate 3
a and an upper plate 3b made of a ceramic sintered body that covers the entire region of the electrode plate 4. The electrode plate 4 is connected to one end of a high-frequency / DC voltage application electrode 5. Further, in the mounting plate 3, it is preferable that the material forming the lower plate 3 a and the material forming the upper plate 3 b be the same material or the same main component. Here, the same main component means that the content of the material other than the main component is 5%.
A material having a content of 0 mol% or less.

The lower plate 3a and the upper plate 3b are
It is joined and integrated by the mounting plate joining layer 7. This mounting plate bonding layer 7 is preferably made of the above-mentioned vitreous bonding layer. With the above-mentioned glassy bonding layer, the same effects as those of the bonding layer 10 can be obtained, and the mounting plate bonding layer 7 having excellent airtightness, high heat resistance, and resistant to deterioration can be obtained.

The thickness of the mounting plate bonding layer 7 is 5 to 180.
It is preferably set to μm. When the thickness of the mounting plate joining layer 7 is less than 5 μm, the fillet is not formed sufficiently at the fine portion of the mounting plate joining layer 7, so that the airtightness of the mounting plate joining layer 7 cannot be secured, and Also lacks strength. on the other hand,
When the thickness of the mounting plate bonding layer 7 exceeds 180 μm, the airtightness of the mounting plate bonding layer 7 can be ensured, but the bonding strength is likely to decrease, and the bonding melted by the pressurizing and heating treatment at the time of bonding The agent may flow out from the end of the mounting plate joining layer 7 and cannot join the lower plate 3a and the upper plate 3b in parallel, thereby lowering the product yield and hindering the joining operation. is there.

The lower plate 3a and the upper plate 3b are
When both are made of an aluminum nitride sintered body or an aluminum nitride based sintered body, they can be joined and integrated by high-temperature pressurization.
There is no need to provide In such a case, for example, between the lower plate 3a and the upper plate 3b, aluminum nitride powder or aluminum nitride powder made of a material having a content of a component other than aluminum nitride of 50 mol% or less is interposed between the bonding surfaces. These can be integrated by high temperature and pressure bonding.

The electrode plate 4 provided inside the mounting plate 3
Is a high-melting-point metal such as molybdenum, tungsten, tantalum, niobium or an alloy thereof having a thermal expansion coefficient close to that of the ceramic sintered body forming the mounting plate 3, or a mixture of these metals and ceramics. It is preferably formed of a composite conductive material. Such an electrode plate 4 can have a coefficient of thermal expansion close to the coefficient of thermal expansion of the aluminum nitride sintered body or the aluminum nitride based sintered body. Further, it is stable to the heat treatment temperature and the atmosphere during the joining process between the support plate 2 and the mounting plate 3. In addition, it has a low specific resistance and can be used for a long time in a practical temperature range from room temperature to 1000 ° C.

The electrode plate 4 can be used as an electrode for an electrostatic chuck, a heater electrode, a plasma generation electrode, and the like.
For example, plasma can be generated by applying a high-frequency voltage from the plasma generation electrode to the electrode plate 4 via the high-frequency / DC voltage application electrode 5. At this time, it is preferable that the electrode plate 4 has a sufficient thickness of 0.01 mm or more. With such a thickness, there is no danger of burning out due to heat generation even when a high-frequency voltage is applied, and unlike the case of using a grid-shaped or mesh-shaped electrode, a dense, stable, and uniform plasma is formed over the entire area. Can be generated. Further, there is an advantage that the connection between the electrode plate 4 and the high-frequency / DC voltage application electrode 5 can be reliably performed between the surface and the rod.

When a high DC voltage of about 500 V is applied to the electrode plate 4 from the electrostatic attraction power supply through the high frequency / DC voltage applying electrode 5, the mounting plate 3 functions as an insulator,
An object to be attracted such as a silicon wafer can be electrostatically attracted. When both the high frequency voltage of the power supply for plasma generation and the high DC voltage of the power supply for electrostatic attraction are applied to the electrode plate 4, a filter capable of cutting high frequency is installed between the power supply for electrostatic attraction and the power supply electrode. do it.

The high-frequency / DC voltage application electrode 5 connected to the electrode plate 4, the heater power supply electrode 9 connected to the heater element 8, and the thermocouple 6 connected to the mounting plate 3 are heat-resistant. It is preferably formed of nickel, tungsten, tantalum, or the like having excellent properties.

The heating device according to this embodiment can be manufactured, for example, as follows. First, a support plate 2 having a concave groove 12 on its surface, and an upper plate 3d and a lower plate 3a serving as the mounting plate 3 are manufactured from a ceramic sintered body.
For example, the support plate 2 and the lower plate 3a are obtained by subjecting a disc-shaped aluminum nitride sintered body or an aluminum nitride-based sintered body formed according to a conventional method to groove processing by an appropriate method. The upper plate 3b is also formed according to a conventional method.

Next, an electrode plate 4 to be held inside the mounting plate 3 is formed. When the electrode plate 4 is made of a composite conductive material of a high melting point metal and a ceramic, a coating material obtained by dispersing a conductive material powder such as a conductive ceramic in an organic solvent such as a screen oil is applied to the lower plate 3a. The electrode plate 4 can be formed by a method of forming the electrode plate 4 by applying a uniform thickness by printing or the like, drying the coating, and the like. When the electrode plate is made of a high melting point metal, a thin plate of a high melting point metal formed by a commonly used metal working method is disposed between the lower plate 3a and the upper plate 3b. The electrode plate 4 can be formed. As another method, there is a method of forming a thin film such as the above-mentioned vapor-deposited film of the high melting point metal.

Then, the lower plate 3 is sandwiched between the electrode plates 4.
a and the upper plate 3b are overlapped, and these are joined and integrated by the mounting plate joining layer 7. Alternatively, when the material constituting the lower plate 3a or the upper plate 3b is an aluminum nitride sintered body or an aluminum nitride-based sintered body, aluminum nitride powder is interposed on the joining surface, and no other joining agent is interposed. , High temperature and pressure bonding.

Next, the heater element 8 is manufactured.
The heater element 8 is described in, for example, Japanese Patent Application Laid-Open No. 4-65361.
Can be produced by any one of the following methods described in Japanese Patent Application Laid-Open No. H10-260,000. (1) A first silicon carbide powder having an average particle diameter of 0.1 to 10 μm and a source gas comprising a silane compound or a silicon halide and a hydrocarbon are introduced into plasma in a non-oxidizing atmosphere, and a reaction is performed. System pressure from less than 1 atmosphere to 1.33 × 10P
a) mixing with a second silicon carbide powder having an average particle diameter of 0.1 μm or less, which is synthesized by reacting a gas phase while controlling within a (0.1 Torr) range, and heating and sintering the mixture. Thereby, a silicon carbide sintered body is obtained, and this sintered body is subjected to electric discharge machining according to a predetermined pattern to form heater element 8. (2) A raw material gas comprising a silane compound or a silicon halide and a hydrocarbon is introduced into plasma in a non-oxidizing atmosphere, and the pressure of the reaction system is reduced from less than 1 atmosphere to 1.33 × 10 Pa
A silicon carbide sintered body is obtained by heating and sintering silicon carbide powder having an average particle diameter of 0.1 μm or less, which is synthesized by performing a gas phase reaction while controlling in a (0.1 Torr) range. The sintered body is subjected to electric discharge machining according to a desired pattern to form a heater element. Next, the heater element 8 formed according to the above method is loaded into the concave groove 12 of the support plate 2.

Next, the finely pulverized vitreous bonding agent, which is the bonding layer 10, is mixed with a screen oil to form a paste, and the paste-like heat-resistant bonding agent is supplied to the support having the concave groove 12 and the heater element 8 loaded therein. It is applied to each joint surface of the plate 2 and the lower plate 3a and dried at 100 to 200C.

Thereafter, the support plate 2 and the mounting plate 3 are laminated with the heater element 8 sandwiched therebetween through the surface coated with the heat-resistant bonding agent, and heated in an electric furnace to form a vitreous joint. The agent is melted and heated at 1300-1500 ° C. for 5-40 minutes to join. This heating is performed under normal pressure or under a pressure of about 10 atm or less. The atmosphere at the time of heating differs depending on the bonding agent used. That is, when a bonding agent containing oxynitride glass is used, since the bonding agent is oxynitrided in advance, a non-nitrogen-containing atmosphere may be used, but a nitrogen-containing atmosphere is preferable. On the other hand, when a bonding agent containing oxide glass is used, a nitrogen source for converting the oxide glass into oxynitride is indispensable, and the bonding is performed in a nitrogen-containing atmosphere. In addition,
Nitrogen-containing atmosphere is obtained by using N ₂ gas, H ₂ -N ₂ mixed gas or NH ₃ gas, or the like.

[0034] The bonding agent that has been heated and melted can have bonding strength by being cooled and solidified. However, by gradually cooling without performing rapid cooling, the oxynitride glass can be maintained while maintaining a high nitrogen uptake. It is preferable to stabilize the layer. The cooling rate is preferably 50 ° C./min or less, more preferably 30 ° C./min or less. In order to keep the thickness of the bonding layer 10 after bonding within the above range, the ratio of the amount of the heat-resistant bonding agent pulverized to the screen oil, the amount of paste-based vitreous bonding agent applied, and the heating during bonding It can be performed by appropriately adjusting processing conditions such as temperature and time.

The bonding agent used for the bonding layer 10 and the mounting plate bonding layer 7 can be manufactured, for example, as follows. First, as the bonding material raw powder, for example, an oxide of at least two elements selected from Group 3a elements of the periodic table, silicon dioxide, and aluminum oxide are mixed, or a compound that is changed to these by heat treatment. Mix. Then, this raw material mixed powder is, for example,
After pulverizing and melting at 1500 to 1700 ° C., it is quenched to obtain a vitreous cooled product, which is pulverized to a particle size of about 5 μm to prepare a bonding agent of a fine powder of a uniform composition.

Here, as an oxide of an element of group a of the periodic table,
Is not particularly limited and Y_TwoO_Three, Dy_TwoO_Three, Er_TwoO_Three, Gd_Two
O_Three, La_TwoO_Three, Yb_TwoO_Three, Sm_TwoO_ThreeTo illustrate etc.
Can be. Of these, price or availability?
One of the oxides of Group 3a element of the periodic table used is Y_TwoO_Three
Is the most suitable, and the oxides of other Group 3a elements of the periodic table are
Y _TwoO_ThreeAnd Dy that easily forms a solid solution_TwoO_Three, Er_Two
O_Three, Gd_TwoO_ThreeAre preferred, and especially Dy_TwoO_ThreeIs the price point
Is also suitable.

The composition ratio of each of the above components is not particularly limited either, but oxides of at least two elements selected from Group 3a elements of the periodic table are in a total amount of 20 to 50% by weight, and silicon dioxide is 30 to 30% by weight. 70% by weight, 10 to 3 aluminum oxide
It is compounded so that a melt containing 0% by weight is formed.
It is preferable because the obtained melt has a low melting point and excellent wettability with ceramic members and the like. Furthermore, Periodic Table No. 3
When there are two kinds of group a elements, it is preferable to mix the oxides of group 3a elements of the periodic table in a molar ratio of about 1: 1 because the melting point of the bonding agent is the lowest.

The atmosphere at the time of preparing the bonding material is not particularly limited. However, when performed in a nitrogen atmosphere, an oxynitride glass is formed, and when performed in a non-nitrogen atmosphere, an oxide glass is formed. However, in this embodiment, since the oxynitride glass layer is formed at the bonding interface, the adjustment of the bonding agent is performed in a nitrogen-containing atmosphere, and the bonding agent is converted into oxynitride glass beforehand. It is preferable to keep it. The nitrogen-containing atmosphere is N ₂ gas, H ₂ −
It can be obtained by using an N ₂ mixed gas or an NH ₃ gas or the like.

It is preferable that Si ₃ N ₄ powder and / or AlN powder be blended in the bonding agent in an amount of 1 to 50% by weight. That is, the addition of Si ₃ N ₄ powder or AlN powder lowers the thermal expansion coefficient of the oxynitride glass and also improves the heat resistance. If the blending ratio is less than 1% by weight, there is no point in adding it, and if it exceeds 50% by weight, the joining strength is lowered, which is not preferable. The particle size of the Si ₃ N ₄ powder and / or AlN powder to be added is not particularly limited, but is preferably 0.8 μm or less in average particle size in that oxynitride glass having a uniform concentration can be formed.

The electrode plate 4 of the heating device 1 thus formed is provided with a high-frequency / DC voltage application electrode 5, the heater element 8 is provided with a heater power supply electrode 9, and the mounting plate 3 is provided with a thermocouple 6 respectively. By connecting, the heating device 1 can be obtained. These electrodes can be manufactured by a commonly used metal working method. As a method of connecting these electrodes, in advance, at a predetermined position of the heating device, fixed holes for fixing these are formed, or after the heating device is created, these fixed holes are cut and cut, Either method of connecting the electrodes to each layer is used.

With such a heating device 1, the mounting plate 3
Since both the support plate 2 and the support plate 2 are made of a ceramic sintered body, they have excellent plasma resistance, can approximate the thermal expansion coefficients thereof, and improve the durability of the bonding interface at these boundary surfaces. The product life will be long. Further, since the thermal conductivity of the mounting plate 3 is higher than the thermal conductivity of the support plate 2, the heat transfer from the heater element 8 to the mounting plate 3 is improved, and the heating efficiency of the heating device 1 is improved. You.
The thermal conductivity is easily adjusted by changing the amount of Y ₂ O ₃ added to each ceramic sintered body without changing the thermal expansion coefficients of the mounting plate 3 and the support plate 2. can do. The mounting plate 3 and the support plate 2 are connected to the bonding layer 1.
0, the airtightness is further improved, the strength at these bonding surfaces, the plasma resistance and the like are excellent, and the product life of the heating device 1 can be improved.

[0042]

The present invention will be described below in detail with reference to examples. A heating device having the structure shown in FIG. 1 was prepared. [Examples 1 to 3] A low thermal conductivity support plate made of an aluminum nitride-based sintered body having a diameter of 220 mm and a thickness of 15 mm provided with a spiral concave groove 12 for loading a heater element 8 having a width of 5 mm and a search distance of 8 mm on the surface. 2 was formed as follows. Aluminum nitride powder not containing Y ₂ O _{3 and} having an average particle diameter of 0.6 μm (F grade powder, manufactured by Tokuyama Corporation) and silicon carbide fine powder having an average particle diameter of 0.03 μm (manufactured by Sumitomo Osaka Cement Co., Ltd.) ) Was mixed at a weight ratio of 99.5: 0.5 with isopropyl alcohol as a dispersion medium, and then granulated using a spray drier.

Then, the obtained granules were placed at 1850 ° C., 20
Pressure sintering was performed under the condition of 0 Kg / cm ² to obtain a disc-shaped sintered body. The obtained disk-shaped sintered body was ground by a conventionally known grinding method to obtain a support plate 2 having the above-described spiral groove 12. The thermal conductivity of the support plate 2 was determined by a laser flash method, and the coefficient of thermal expansion was determined by a thermal dilatometer (TMA).
When each was measured, the thermal conductivity was 57.7 W / mK.
And the coefficient of thermal expansion was 4.7 × 10 ⁻⁶ / ° C.

On the other hand, a mixed powder of the aluminum nitride powder, the silicon carbide fine powder, and the yttria powder (manufactured by Nippon Yttrium Ltd.) in a weight ratio of 99.5: 0.5: 3.0 was used. According to the method of forming the support plate 2, a lower plate 3a made of a disc-shaped aluminum nitride-based sintered body having a diameter of 220 mm and a thickness of 8 mm, and an upper plate made of an aluminum nitride-based sintered body having a diameter of 220 mm and a thickness of 1 mm 3b was produced. When the thermal conductivity of the lower plate 3a and the upper plate 3b was measured by the method described above, both were 110 W / mK.
The heat conductivity of the support plate 2 was better than that of the support plate 2. When the thermal expansion coefficients of the lower plate 3a and the upper plate 3b were measured by the above method, it was found to be 4.4 × 10 ⁻⁶ / ° C.
Which was close to the coefficient of thermal expansion of the support plate.

Further, sintering is performed without adding a sintering aid or an additive for imparting conductivity, and the sintering density is 3.
1 g / cm ³ , electrical resistivity at room temperature is 0.05Ω · cm
Of the silicon carbide sintered body, and the spiral groove 12
The heater element 8 having a shape that can be loaded into the heater element 8 was formed by the method (1) for manufacturing the heater element 8 described above. First
The average particle size of the silicon carbide powder is 0.7 μm, and the addition amount is 95 μm.
%, The average particle size of the second silicon carbide is 0.01 μm, the addition amount is 5% by weight, and the hot press sintering conditions are a pressing pressure of 400 kg / cm ² , a sintering temperature of 2200 ° C., and a sintering time of 90 minutes. It is.

On the other hand, a coating agent containing a tungsten powder having an average particle size of 0.5 μm and a commercially available screen oil was screen-printed on the lower plate in an electrode shape. In addition, a coating material containing the above-mentioned aluminum nitride powder and a commercially available screen oil was screen-printed on a region other than the electrode forming portion on the lower plate 3a. Then, the lower plate 3a and the upper plate 3b are overlapped with each other via the screen printing surface, and
The electrode plate made of tungsten is integrated by heat treatment under the conditions of 800 ° C. and 75 kg / cm ² , and the lower electrode plate 3a and the upper electrode plate 3
The mounting plate 3 sandwiched between b was obtained.

Next, a vitreous heat-resistant bonding agent (particle size: about 2 μm) having the composition shown in Table 1 was mixed with a commercially available screen oil to form a base. It is applied to the respective joint surfaces of the ceramic sintered body support plate 2 and the ceramic sintered body mounting plate 3 in which the heater elements 8 are loaded in the spiral concave grooves 12, and dried at 100 to 200 ° C. did.

Thereafter, the support plate 2 and the mounting plate 3 are separated from each other via the surface on which the glassy heat-resistant bonding agent is applied.
The heater element 8 is laminated while being sandwiched, and N ₂
The vitreous heat-resistant bonding agent was melted by heating in an electric furnace in a gas atmosphere, and heated at 1450 ° C. for 20 minutes to perform air-tight bonding. The cooling rate was 25 ° C./min, and the thickness of the bonding layer 10 after bonding was 50 μm. Further, it was confirmed by Auger electron spectroscopy that oxynitride glass was formed at the bonding interface.

The airtightness of the joining portion between the support plate 2 made of the aluminum nitride-based sintered body and the lower plate 3a made of the aluminum nitride-based sintered body of the heating apparatus 1 of Examples 1 to 3 thus obtained. In order to confirm the above, a durability test was performed. Further, when the bonding interface between the lower plate 3a and the upper plate 3b was observed by SEM, the lower plate 3a and the upper plate 3b were satisfactorily bonded and integrated.

(Durability test) The heating device 1 is energized, heated from room temperature to a maximum temperature of 700 ° C. for 1 hour, kept at the maximum temperature for 30 minutes, and then gradually cooled to room temperature. The airtightness of the joint after the heat cycle was applied 100 times was tested by a leak test using He gas.
In addition, the evaluation criteria of airtightness are as follows. ；: He leak amount is 1.33 × 10 ⁻⁷ Pa / sec or less Δ: He leak amount is 1.33 × 10 ^{−7 to} 1.33 × 1
0 ⁻⁶ Pa / sec ×; He leak amount is 1.33 × 10 ⁻⁶ Pa / sec or more

Example 4 Example 1 was repeated except that a mixed powder of the aluminum nitride powder, the silicon carbide fine powder, and the yttria powder in a weight ratio of 99.5: 0.5: 10.0 was used. The support plate 2 was formed according to the method described in (1) to (3). When the thermal conductivity and the coefficient of thermal expansion of the support plate 2 were measured according to Examples 1 to 3, they were 140 W / mK and 3.9 × 10 ⁻⁶ , respectively.
/ ° C. Similarly, in Examples 1 to 3, except that a mixed powder of the aluminum nitride powder, the silicon carbide fine powder, and the yttria powder in a weight ratio of 99.5: 0.5: 10.0 was used. The lower plate 3a and the upper plate 3b were formed according to the method. And these support plate 2, lower plate 3a,
The heating device 1 of Example 4 was produced according to Examples 1 to 3 except that the bonding agent having the composition shown in Table 1 was used, using the upper plate 3b. The durability of the obtained heating device 1 of the fourth embodiment is shown in the first embodiment.
Tested according to. The test results are shown in Table 1. Further, when the bonding interface between the lower plate 3a and the upper plate 3b was observed by SEM, the lower plate 3a and the upper plate 3b were satisfactorily bonded and integrated.

[0052]

[Table 1]

[0053]

As described above, according to the present invention,
Since the support plate and the mounting plate are formed from a ceramic sintered body, the coefficient of thermal expansion of the support plate and the mounting plate can be set to approximate values, so that the strength of these interfaces is improved. The durability is increased, the plasma resistance is improved, and the product life can be extended. In addition, since the thermal conductivity of the mounting plate is higher than the thermal conductivity of the support plate, the heat generated from the heater element is intensively transmitted to the mounting plate, and the heat on the mounting side is also increased. It is possible to effectively prevent heat dissipation on the side of the support plate on which the object to be heated is not placed while maintaining the conductivity, and the thermal efficiency of the heating device is dramatically improved. Further, the ceramic sintered body, Y ₂ O ₃ auxiliaries and the aluminum nitride sintered body, or, Y ₂ O ₃ with aid and the aluminum nitride-based sintered body, and these Y ₂ By adjusting the O ₃ content, the thermal conductivity of the mounting plate and the support plate can be easily adjusted without changing the coefficient of thermal expansion thereof, and the above-described effects can be easily achieved. be able to.

Further, if the mounting plate and the supporting plate are joined and integrated by a vitreous joining layer, the heating device can improve the strength of these connecting surfaces and improve the airtightness of these connecting surfaces. Since the connection surfaces can be further increased, the strength of these connection surfaces is improved, and the life can be further extended. Further, if the mounting plate is composed of a lower plate and an upper plate and an electrode plate is formed between them, by using the electrode plate for various purposes, the heating device is used for various purposes. be able to.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a heating device of the present invention.

FIG. 2 is an exploded cross-sectional view for explaining each part of the example of the heating apparatus of the present invention shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heating device, 2 ... Support plate 3 ... Placement plate, 3a ... Lower plate 3b ... Upper plate, 4 ... Electrode plate 5 ... For high frequency / DC voltage application Electrode 6 ... Thermocouple 7 ... Mounting plate joining layer 8 ...
Heater element 9: Heater power supply electrode 10: Bonding layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K034 AA02 AA05 AA21 AA34 BC07 BC15 BC16 BC17 CA32 HA01 HA10 JA02 3K092 PP20 QA05 QB02 QB09 QB44 QB76 RF11 RF19 RF25 RF26 VV15 VV31 VV34 4G001 BA09 BA22 BA36 BB09BC BD03 BD36

Claims (4)

[Claims] 1. A mounting plate on which an object to be heated is mounted, a supporting plate integrated with the mounting plate, a heater element sandwiched between the mounting plate and the supporting plate, and the heater element A heating device provided with at least one pair of electrodes having one end connected to the mounting plate, wherein the mounting plate and the support plate are both made of a ceramic sintered body, and the heat of the ceramic sintered body constituting the mounting plate is provided. A heating device, wherein the conductivity is higher than the thermal conductivity of the ceramic sintered body constituting the support plate. Wherein said ceramic sintered body, Y ₂ O ₃ auxiliaries and the aluminum nitride sintered body, or a nitride aluminum based sintered body in which the Y ₂ O ₃ and auxiliaries, and, prior to heating apparatus according to claim 1, the content of Y ₂ O ₃ sintered ceramics of the mounting plate, characterized in that more than Y ₂ O ₃ content of the ceramic sintered body of the support plate. 3. The heating device according to claim 1, wherein the supporting plate and the mounting plate are joined and integrated by a vitreous joining layer. 4. The mounting plate according to claim 1, wherein the mounting plate comprises an upper plate and a lower plate, and an electrode plate is sandwiched between the upper plate and the lower plate, and an electrode is connected to the electrode plate. Item 4. The heating device according to any one of Items 1 to 3.