JP2006013302A - Substrate mounting device and substrate temperature adjusting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate mounting device which is further inexpensive, has a simple structure and can adjust in-plane temperature distribution of a substrate temperature, and a substrate temperature adjusting method. <P>SOLUTION: The substrate mounting device has a plate-like ceramics base material with a substrate mounting surface in one surface and a junction layer formed on the other surface of the ceramics base material. The plane is divided into a plurality, and junction of different thermal conductivities is disposed in each region. The in-place temperature distribution of the substrate mounted on the ceramics base material is adjusted by adjusting in-plane distribution of thermal conductivity in a junction layer formed on the other surface of the ceramic base material with the substrate mounting surface in the one surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substrate mounting apparatus such as a susceptor, an electrostatic chuck or a ceramic heater used in a semiconductor process or the like, and a substrate temperature adjusting method in these apparatuses.

  In a semiconductor process or a liquid crystal display manufacturing process, a substrate mounting device such as a susceptor, an electrostatic chuck, or a ceramic heater with a built-in heater is used to mount a substrate such as a silicon wafer or glass. Further, in the high-frequency plasma processing apparatus, a substrate mounting apparatus having a cooling function is also used in order to reduce the substrate temperature that has been raised by the plasma irradiation.

  In a semiconductor process, the in-plane temperature distribution on the surface of the substrate affects in-plane variations such as the film quality and etching characteristics of the thin film to be produced. However, the temperature distribution in the substrate surface is greatly influenced not only by the temperature distribution of the ceramic heater provided in the substrate mounting apparatus, but also by the usage environment other than the substrate mounting apparatus, such as the heat input distribution from the plasma. receive.

  Therefore, even if the substrate placement surface temperature distribution of the substrate placement apparatus itself is adjusted to be uniform, it is difficult to form a uniform temperature distribution on the actual substrate surface due to the external factors described above. It is. Therefore, in order to optimize the substrate temperature distribution, the plasma conditions are optimized and the shape and material of the members arranged around the substrate mounting apparatus are adjusted.

Moreover, according to the heat input distribution from plasma, the electrostatic chuck apparatus (patent document 1) which adjusted the unevenness | corrugation of the board | substrate mounting surface according to the place, and the inside of the ceramic base material used as a board | substrate mounting surface are divided into several zones. A multi-zone heater (Patent Document 2) that embeds a heater independently for each zone and adjusts the heat generation amount has also been proposed.
Japanese Patent Laid-Open No. 7-18438 (FIG. 1) Japanese Patent Laid-Open No. 2001-52843 (FIG. 1)

  However, there is a limit to the range that can be adjusted by the conventional optimization method that adjusts the substrate temperature distribution by optimizing the plasma conditions and adjusting the unevenness of the members placed around the substrate mounting apparatus and the substrate mounting surface.

  On the other hand, in the method of embedding an optimal heater for each zone in consideration of the expected plasma irradiation conditions and the like, a burden is imposed on the design of the heater, and the price of the substrate mounting apparatus is also expensive. Moreover, once it is manufactured, it is difficult to correct it according to changes in the use environment, so that it is not versatile. Furthermore, when the required substrate temperature is relatively low, it is necessary to cool the substrate rather than heating the heater. Therefore, it is desirable to be able to adjust the in-plane substrate temperature distribution with a structure that does not use a heater.

  An object of the present invention is to provide a substrate mounting apparatus and a substrate temperature adjusting method capable of adjusting the in-plane temperature distribution of the substrate temperature, which are simpler and more versatile in view of the above-described conventional problems.

  A substrate mounting apparatus according to an aspect of the present invention includes a plate-shaped ceramic base material having a substrate mounting surface on one surface, and a bonding layer formed on the other surface of the ceramic base material. Is divided into a plurality of regions, and bonding materials having different thermal conductivities are arranged for each region.

  The method for adjusting the substrate temperature according to the aspect of the present invention adjusts the in-plane distribution of the thermal conductivity in the bonding layer formed on the other surface of the ceramic base material having the substrate mounting surface on one surface, The in-plane temperature distribution of the substrate placed on the ceramic substrate is adjusted.

  According to the substrate mounting apparatus according to the aspect of the present invention, the temperature distribution on the substrate surface arranged on the substrate mounting surface can be adjusted with a simple configuration.

  According to the substrate temperature adjusting method according to another aspect of the present invention, the temperature distribution on the substrate surface arranged on the substrate mounting surface can be adjusted by a simple and versatile method.

  Hereinafter, an electrostatic chuck and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1A shows a schematic cross-sectional view of a substrate mounting apparatus 1 according to an embodiment of the present invention. The substrate mounting device 1 includes a plate-shaped ceramic base material 10 having a substrate mounting surface on one surface, and a bonding layer 20 formed on the other surface of the ceramic base material 10. The layer 20 is divided into a plurality of regions within the substrate surface and is formed of a bonding material having different thermal conductivity for each region. In addition, it is preferable that the base plate 30 that is a plate-like base is preferably bonded to the ceramic substrate 10 via the bonding layer 20.

  According to the substrate mounting apparatus 1 according to the present embodiment, since the in-plane distribution of the thermal conductivity of the bonding layer 20 disposed on the other surface of the ceramic base material 10 can be adjusted, the ceramic base material 10 from the substrate can be adjusted. And the cooling efficiency by the heat transfer to the joining layer 20 can be changed with a place. Therefore, the in-plane temperature distribution of the substrate placed on the ceramic substrate 10 can be adjusted. In particular, when the base plate 30 is bonded to the ceramic substrate 10 via the bonding layer 20, the effect of cooling the substrate temperature due to heat transfer to the base plate 30 via the bonding layer 20 becomes greater. The effect of the temperature adjustment function by adjusting the in-plane distribution of conductivity is also great.

  FIG. 1B shows a plan view of the bonding layer 20 formed on the other surface of the ceramic substrate 10. Here, the bonding layer 20 is divided into two regions of a central portion 20B and an outer peripheral portion 20A in the plane, the first bonding material is disposed on the outer peripheral portion 20A, and the heat conduction different from that of the first bonding material is performed on the central portion 20B. The example in which the 2nd bonding material which has a rate is arranged is shown.

  In the case where the substrate mounting apparatus 1 according to the present embodiment is used in a plasma processing apparatus such as a plasma CVD apparatus or a plasma dry etching apparatus, the substrate surface temperature distribution is higher at the periphery of the substrate than at the center of the substrate. There is. In this case, it is considered that the temperature of the substrate surface tends to be higher at the outer edge of the substrate than at the center of the substrate due to the influence of the plasma intensity distribution and the device structure. Therefore, when the substrate mounting apparatus 1 according to the present embodiment is used in such an environment, a bonding material having a low thermal conductivity is disposed in the central portion 20B of the bonding layer 20, and the outer peripheral portion 20A of the bonding layer 20 is used. It is preferable to arrange a bonding material having a high thermal conductivity. At the edge of the substrate where the substrate temperature is likely to be high, the cooling proceeds efficiently due to the bonding material having a high thermal conductivity, so that an excessive temperature rise can be avoided and the substrate temperature is likely to be lower than the edge of the substrate. Then, the cooling of the substrate temperature is suppressed by disposing a bonding material having a low thermal conductivity. As a result, the nonuniform distribution of the substrate surface temperature caused by the distribution of the plasma intensity and the apparatus structure can be corrected, and the substrate temperature can be made in-plane uniform.

  In FIG. 1A and FIG. 1B, the bonding layer 20 is divided into two regions of a central portion 20B and an outer peripheral portion 20A, and bonding materials having different thermal conductivities are arranged in each region. As shown, a structure in which the surface of the bonding material layer 20 is divided into three regions 20A to 20C and a bonding material having a lower thermal conductivity is arranged toward the inner side may be employed. Furthermore, the number of areas to be divided may be increased as necessary.

  As described above, the substrate surface temperature distribution may have various temperature distributions depending on the use conditions and the device structure, as well as the case where the substrate surface temperature is low at the central portion and high at the peripheral portion. Therefore, it is desirable to adjust the in-plane distribution of the thermal conductivity of the bonding material in accordance with the substrate surface temperature distribution.

  Moreover, the form of the region division of the bonding layer 20 is not limited to the form of concentric division from the central portion, and various division forms can be adopted according to the necessary temperature adjustment conditions. For example, when a through hole is opened for a substrate lift pin or a purge gas in the substrate mounting device, the substrate surface temperature corresponding to that portion is locally high or low. In this case, as shown in FIG. 2B, in order to correct a local temperature change, a bonding material having a thermal conductivity different from the surroundings may be disposed in the region 20D of the corresponding bonding layer 20. . Alternatively, when the temperature of a part of the substrate is likely to decrease due to an exhaust port or other components in the semiconductor manufacturing apparatus in which the substrate mounting apparatus 1 is disposed, the bonding corresponding to the region where the temperature is likely to decrease is performed. A bonding material having low thermal conductivity may be disposed in the region of the layer 20.

  Thus, according to the method of adjusting the in-plane distribution of the thermal conductivity of the bonding material in the bonding layer, the in-plane temperature distribution of the substrate can be adjusted by a simple method, and an organic bonding material can be used. If used, the bonding layer 20 can be easily removed, so that the thermal conductivity distribution in the bonding layer 20 is appropriately changed according to the change in the usage environment of the substrate platform 1. Is also easy. Therefore, versatility is also extremely high.

  Another form of the substrate mounting apparatus according to the present embodiment shown in FIGS. 3A and 3B is shown. As shown in FIG. 3A, it is preferable to embed an electrostatic chuck electrode 40 in the ceramic substrate 10 to provide the substrate mounting device 2 having an electrostatic chuck function. Since the substrate can be brought into close contact with the mounting surface of the ceramic substrate 10 by the electrostatic chuck function and the heat transfer efficiency from the substrate mounting device 2 can be increased, the substrate temperature distribution can be accurately controlled.

  Further, as shown in FIG. 3B, not only the electrostatic chuck electrode 40 but also the substrate mounting device 3 in which the resistance heating element 50 is embedded may be used. Moreover, as shown in FIG.3 (b), you may use the thing provided with cooling functions, such as the cooling fluid flow path 60 which can circulate a cooling fluid, as the baseplate 30. FIG. By providing the resistance heating element 50, since the heater function is added, the substrate temperature can be raised. If a multi-zone heater capable of setting individual temperatures for each region is used as the resistance heating element 50, adjustment in a wider temperature range is possible.

  Further, the substrate mounting apparatus according to the present embodiment can be further combined with another means for adjusting the in-plane temperature distribution of the substrate temperature to further enhance the function of adjusting the in-plane temperature distribution of the substrate. . For example, as shown in FIG. 4A and FIG. 4B, a plurality of convex portions are arranged on the surface corresponding to the substrate mounting surface of the ceramic base material 10, and the convex portion substrate in contact with the substrate is arranged. The in-plane temperature distribution of the substrate temperature can be adjusted by changing the area of the contact surface depending on the location. In this case, the contact area corresponds to the area of the convex portion.

  When the substrate mounting apparatus 4 is used in the plasma processing apparatus, when the substrate surface temperature is low at the center of the substrate and high at the edge of the substrate, for example, as shown in FIGS. 4 (a) and 4 (b). Further, a convex portion 70C having a small contact area with the substrate is formed in the central portion of the substrate mounting surface of the ceramic base material 10, and a convex portion 70B having a larger contact area is formed around the convex portion 70B. A convex portion 70C having a larger contact area with the substrate is formed. Since the contact area between the convex portion 70C and the substrate is small at the central portion of the substrate placement surface, the cooling effect due to heat transfer is suppressed, and the contact area between the convex portion 70A and the substrate is large at the outer periphery portion of the substrate placement surface. As a result of promoting the cooling effect, it is possible to correct the distribution of the plasma intensity and the uneven distribution of the substrate temperature due to the apparatus structure.

  Here, the substrate placement surface is divided into three regions concentrically, and a substrate placement surface is formed in which convex portions having a predetermined contact area are formed in each region. Various forms can be adopted according to the substrate surface temperature and use conditions. For example, contrary to the structure shown in FIG. 4B, a convex part having a large contact area with the substrate is arranged at the center of the substrate mounting surface, and a convex part having a small contact area with the substrate is provided on the outer peripheral side. You may arrange.

  In this way, in addition to the adjustment of the in-plane distribution of the bonding material, by adjusting the contact area distribution of the convex portion of the substrate mounting surface, the substrate temperature distribution can be finely adjusted, and a more accurate desired A temperature distribution can be obtained.

 Hereinafter, each constituent material of the substrate mounting apparatus according to the present embodiment will be specifically described.

First, as the ceramic substrate 10, various ceramic materials can be used. For example, oxide ceramics such as alumina (Al ₂ O ₃ ), aluminum nitride (AlN), silicon nitride (Si ₃ N ₄ ), boron nitride ( BN), nitride ceramics such as sialon, and dense sintered bodies of carbonized ceramics such as silicon carbide (SiC) can be exemplified. Of these materials, AlN can be suitably used because it has good corrosion resistance and high thermal conductivity. In addition, the shape of the ceramic base material 10 can employ | adopt various shapes according to the magnitude | size and shape of the board | substrate which should be mounted. The substrate placement surface is not limited to a circular shape, and may be a rectangle or a polygon.

 The base plate 30 is preferably provided with a cooling function, and it is preferable to use a metal material or a composite material of metal and ceramics having relatively high thermal conductivity. Specific examples of the base plate material include, but are not limited to, Al, Cu, brass, and SUS.

 The ceramic material constituting the composite material is not particularly limited, and a porous ceramic material that is the same as or different from the ceramic dielectric substrate 10 can be used. For example, alumina, aluminum nitride, silicon carbide, silicon nitride, sialon, or the like can be used. On the other hand, the metal to be filled in the porous ceramic material is preferably a metal having high corrosion resistance and good filling properties. For example, Al or an alloy of Al and Si can be preferably used.

 It is possible to use not only an organic but also an inorganic glass bonding material, but in order to reduce the difference in thermal expansion between the base plate 30 and the ceramic dielectric substrate 10, an organic bonding material having a low bonding temperature should be used. Is preferred.

Moreover, in the substrate mounting apparatus 1 of the present embodiment, the bonding layer 20 is divided into a plurality of regions within the plane, and bonding materials having different thermal conductivities are used for each region. Bonding materials with completely different compositions may be used for each region, but the desired thermal conductivity can be adjusted by adjusting the filler content by using, for example, a bonding material containing a filler in the organic bonding material. May be. Specifically, it is desirable to use a polyimide resin, a silicone resin, an acrylic resin or the like as a base material, and add a filler such as Al ₂ O ₃ , AlN, TiB, or Al as necessary.

 The value of the thermal conductivity of the bonding material to be used is not limited. For example, as shown in FIG. 1B, the bonding layer 20 is divided into two regions, and a bonding material having a high thermal conductivity is arranged in one region. When a bonding material with low thermal conductivity is arranged in the other region, for example, as a bonding material with high thermal conductivity, a bonding material having a thermal conductivity 1.1 to 100 times that of the low bonding material, if necessary Thus, a bonding material having a thermal conductivity of 100 times or more can be used.

 In addition, in order to make handling of a manufacturing process easier, you may utilize the adhesive sheet by which the organic adhesive agent was apply | coated to both surfaces of a sheet-like organic bonding material or a sheet-like organic resin as the joining layer 30. FIG.

As shown in FIG. 3A, when the ceramic substrate 10 is embedded with the electrostatic chuck electrode 40, the electrostatic chuck attracting mechanism uses the Coulomb force between the electrode and the substrate. The type may also be a type that uses the Johnson-Rahbek force that uses the adsorption force of the gap between the ceramic substrate surface and the substrate. When using the Coulomb force, the specific resistance at the operating temperature of the dielectric layer of the ceramic substrate 10, particularly between the electrostatic chuck electrode 40 and the substrate mounting surface, is set to 10 ¹⁴ Ω · cm or more, and the dielectric The layer thickness is preferably 0.5 mm or less. On the other hand, when using the Johnson-Rahbek force, the dielectric layer has a specific resistance at the operating temperature of 10 ⁷ Ω · cm to 10 ¹² Ω · cm and a thickness of the dielectric layer of 0.2 mm to 5 mm. Is preferably used.

 For the electrostatic chuck electrode 40, for example, refractory metals such as Mo, W, and WC can be used, and the form thereof is not particularly limited. As the electrostatic chuck electrode 40, a paste-like metal is printed, a film electrode formed by drying and baking, a physical thin film such as sputtering or ion beam vapor deposition, or a metal thin film is formed by chemical vapor deposition such as CVD. The pattern electrode may be formed by etching. Or the electrode which consists of bulk metals, such as a metal-mesh (mesh), can also be used.

3B, when the ceramic base material 10 in which the resistance heating element 50 is embedded is formed, the material of the resistance heating element 50 is molybdenum (Mo), tungsten (W), molybdenum carbide ( High melting point conductive materials such as MoC) and tungsten carbide (WC) can be preferably used. Besides refractory metals, Ni, TiN, TiC, TaC, NbC, HfC, HfB ₂ , ZrB ₂ , carbon, and the like can be used. Not only a linear thing but various forms, such as ribbon shape, mesh shape, coil spring shape, sheet shape, and a printed electrode, can also be used.

 Next, a method for manufacturing the substrate mounting apparatuses 1 to 4 according to the present embodiment will be described.

First, the ceramic substrate 10 and the base plate 30 are respectively produced. In order to produce the ceramic substrate 10, a ceramic raw material powder such as aluminum nitride and a sintering aid raw material such as yttria (Y ₂ O ₃ ), silica (SiO ₂ ) or alumina (Al ₂ O ₃ ) as required. The powder is mixed at a predetermined mixing ratio and mixed using a pot mill or a ball mill. Mixing may be either wet or dry. When wet is used, drying is performed after mixing to obtain a raw material mixed powder. Thereafter, molding is performed using the raw material mixed powder as it is or granulated by adding a binder to obtain, for example, a disk-shaped molded body. The molding method is not limited, and various methods can be used. For example, a mold forming method, a CIP (Cold Isostatic Pressing) method, a slip casting method, or the like can be used. Further, the obtained molded body is obtained by using a hot press method or an atmospheric pressure sintering method, in the case of aluminum nitride, about 1700 ° C to about 1900 ° C, in the case of alumina, about 1600 ° C, and in the case of sialon, about 1700 ° C. C. to about 1800.degree. C., and in the case of silicon carbide, it is fired at about 2000.degree. C. to about 2200.degree. C. to produce a sintered body.

 In the case where the electrostatic chuck electrode 40 and the resistance heating element 50 are embedded in the ceramic substrate 10, each electrode is embedded in the forming process. For example, in the case of the electrostatic chuck electrode 40, a perforated planar electrode made of a metal bulk body, more preferably, a mesh (metal mesh) electrode may be embedded in the raw material powder. When the resistance heating element 50 is embedded, a metal bulk body processed into a predetermined shape such as a coil shape or a spiral shape is embedded as in the electrostatic chuck electrode. For any electrode, it is preferable to use a refractory metal such as molybdenum or tungsten.

 Further, as the electrostatic chuck electrode 40, a film-like electrode formed by printing a paste-like metal, drying, and firing can be used. In this case, in the molding process, for example, two disc-shaped green sheets are produced, a paste-like metal electrode is printed on one surface thereof, the other green sheet is laminated with the printed electrode being sandwiched, A green sheet laminate may be produced and the green sheet laminate may be fired.

 The base plate 30 can be made of a composite material or a metal material as a base, and a cold water channel can be formed as necessary.

 Next, the ceramic substrate 10 and the base plate 30 are bonded via the bonding layer 20. In this joining step, first, a plurality of joining materials having different thermal conductivities are arranged on the back surface of the ceramic substrate 10. For example, the bonding material may be patterned on one surface of the ceramic substrate 10 or the base plate 30 by using a printing method, or a plurality of sheet-shaped bonding materials may be formed on the ceramic substrate 10. And a predetermined position between the base plate 30 and the base plate 30. Thereafter, the temperature is raised to the curing temperature of the bonding material in vacuum or in the air, and pressure is applied to bond the two together.

 Hereinafter, a simulation of substrate temperature distribution performed in order to confirm the effect of the present invention and examples of the present invention will be described.

<Example of simulation>
First, the surface of the ceramic substrate 10 expected when the surface of the bonding layer 20 interposed between the ceramic substrate 10 and the base plate 30 is divided into a plurality of regions and materials having different thermal conductivities are arranged in each region. The temperature distribution on the (substrate mounting surface) was simulated using the finite element method. In addition, when the substrate mounting apparatus 2 is disposed in the plasma processing apparatus, the temperature of the surface of the ceramic base material 10 increases due to heat input from the plasma. Here, it is assumed that the temperature increases uniformly in the plane. .

 Table 1 shows the simulation conditions. Note that the simulation target is the substrate mounting apparatus 2 having the structure shown in FIG. That is, the ceramic base material 10 in which the electrostatic chuck electrode 40 is embedded and the base plate 30 are joined by the joining layer 20, and the joining layer 20 is divided into two regions of the central portion 20A and the outer peripheral portion 20B in the plane. In each region, bonding materials having different thermal conductivities are used. Table 1 shows the specific material and size of each structure used in the simulation, and the thermal conductivity of the bonding material.

 It is assumed that the temperature of the bottom surface of the base plate 30 is 20 ° C., and the energy input from the plasma to the ceramic substrate 10 is 300 W, 500 W, and 700 W, respectively, under three conditions. In addition, the bonding layer 20 was divided into two regions, a central portion and an outer peripheral portion thereof, and bonding layers having different thermal conductivities were arranged in the respective regions. As the size of the central bonding layer, three conditions of φ60 mm, φ120 mm, and φ140 mm were assumed.

The simulation results when AlN is used as the ceramic substrate are shown in Table 2 and FIG. Also shows the simulation result in the case of Al ₂ O ₃ is used as the ceramic base material in Table 3 and Figure 6.

  As shown in Table 2, Table 3, FIG. 5 and FIG. 6, when the heat input power from the plasma to the substrate mounting surface of the ceramic base material is uniform in the plane, the joining interposed between the ceramic base material and the base plate The material is divided into a central part and its outer peripheral part in a plane, a bonding material having a low thermal conductivity is arranged in the central part, and a bonding material having a higher thermal conductivity is arranged in the outer peripheral part, thereby placing the substrate on the substrate. It was found that it was possible to form a lower temperature distribution on the surface in the periphery than in the center. Although not shown in the graph, when the bonding layer is formed of a single bonding material, the temperature distribution on the substrate mounting surface of the ceramic substrate is substantially uniform.

 Therefore, when the substrate mounting apparatus according to this embodiment is actually used in the plasma processing apparatus, if the substrate temperature becomes non-uniform due to a problem in the apparatus structure, the thermal conductivity of the bonding material in the bonding layer It was confirmed that the temperature of the substrate surface can be equalized by changing the position depending on the location. In addition, the adjustment of the substrate temperature distribution is performed by dividing the in-plane of the bonding layer into a plurality and using a bonding material having a predetermined thermal conductivity for each region, but the size and shape of the region where the bonding layer is divided, It was confirmed that the temperature distribution on the substrate mounting surface of the ceramic base material can be easily and effectively adjusted by the thermal conductivity value of the bonding material used.

 For example, the temperature difference between the central portion and the outer peripheral portion on the substrate mounting surface of the ceramic base material is changed to 0 to 5 ° C. by changing the thermal conductivity of the bonding material disposed at the central portion and the outer peripheral portion of the bonding layer at least twice. It becomes possible to adjust. Furthermore, it is possible to freely adjust the temperature by changing the thermal conductivity setting and the in-plane distribution of the bonding material. The temperature difference between the central portion and the outer peripheral portion on the substrate mounting surface of the ceramic base material is changed in the range of 0 to 30 ° C. by changing the thermal conductivity of the bonding material arranged at the central portion and the outer peripheral portion of the bonding layer by 10 times or more. It was also confirmed that adjustment was possible.

<Examples 1 and 2>
As the substrate mounting apparatus of Examples 1 and 2, as shown in FIG. 7, a ceramic base material 10 in which an electrostatic chuck electrode 40 is embedded, a base plate 30 having a cooling water flow path, and a joint interposed between the two. The substrate mounting apparatus having the layer 20 was manufactured in which the bonding layer 20 was divided into a central portion and an outer peripheral portion thereof in a plane, and a bonding material having different thermal conductivity was used for each region.

Specifically, the ceramic substrate 10 was produced under the following conditions. That is, first, an acrylic resin binder was added to the AlN powder obtained by the reduction nitriding method, and granulated granules were prepared by the spray granulation method. This granulated granule was uniaxially pressed using a mold. In addition, in this shaping | molding, Mo bulk electrode which is a plate-shaped mesh electrode was embed | buried in the molded object. This molded body was hot-press fired to produce an integrally sintered product. The pressure during hot pressing was 200 kg / cm ^2, and during firing, the temperature was increased to a maximum temperature of 1900 ° C. at a rate of temperature increase of 10 ° C./hour, and this maximum temperature condition was maintained for 1 hour. Thus, a disk-shaped AlN ceramic substrate 10 having a diameter of 200 mm and a thickness of 5 mm was produced. The volume resistivity of this ceramic substrate 10 was 1E + 10 Ωcm at room temperature. In addition, the board | substrate mounting surface of the ceramic base material 10 was made into the flat surface without attaching an unevenness | corrugation.

 On the other hand, as the base plate 30, an Al plate processed to have a cooling water passage of about Φ240 mm and a thickness of 30 mm was used.

In the substrate mounting apparatus of Example 1, between the AlN ceramic substrate 10 and the base plate 30, a circular acrylic sheet having a thermal conductivity of 1.4 W / mK and a diameter of 60 mm and a thermal conductivity of 0.6 W / mK, an inner diameter of 60 mm. The ceramic substrate 10 and the base plate 30 were joined by applying a pressure of 200 psi (1.38 × 10 ⁶ Pa) from above and below in a vacuum atmosphere at 100 ° C. with a ring-shaped sheet having an outer diameter of Φ200 mm.

In addition, in the substrate mounting apparatus of Example 2, a Φ140 mm circular acrylic sheet having a thermal conductivity of 1.4 W / mK and a thermal conductivity of 0.6 W / mK are provided between the AlN ceramic base material 10 and the base plate 30. The ceramic substrate 10 and the base plate 30 are joined by applying a pressure of 200 psi (1.38 × 10 ⁶ Pa) from above and below in a vacuum atmosphere at 100 ° C. with a ring-shaped sheet having an inner diameter of Φ140 mm and an outer diameter of Φ200 mm. It was.

 As shown in FIG. 7, the substrate mounting apparatus of Examples 1 and 2 is installed in a vacuum chamber 100 provided with a lamp heater 120, and a thermocouple 90 is placed at a predetermined position on the substrate mounting surface of the ceramic substrate 10. A Si substrate with Al terminals brazed with Al was placed. The temperature of the cooling water flowing through the base plate 30 was 20 ° C. After simulating the heat input to the substrate from the plasma generated when the substrate mounting apparatus is used in the plasma processing apparatus, the inside of the vacuum chamber 100 is set to 1 Pa or less, and then the lamp heater 120 is used to heat the substrate. Went. The output of the lamp heater 120 was set to 300 W or 700 W, and the temperatures of the Si substrate center and the Si substrate end were measured. The measurement results are shown in Table 3 and FIG.

 Since the heat input from the lamp heater 120 is adjusted to be substantially uniform in the substrate surface, when the bonding layer is formed of a single bonding material, a substantially uniform substrate temperature distribution can be obtained in the surface. The bonding layer interposed between the ceramic substrate and the base plate is divided into a central portion and its outer peripheral portion in the plane, a bonding material having a low thermal conductivity is arranged in the central portion, and the thermal conductivity is larger than that in the outer peripheral portion. A bonding material was placed. It was also confirmed in the examples that the substrate placement surface temperature of the ceramic base material 10 can be formed in a lower temperature distribution in the peripheral portion than in the peripheral portion.

The simulation result and the actual measurement result are in good agreement, and the substrate temperature adjustment method according to the present embodiment for adjusting the thermal conductivity distribution in the surface of the bonding layer is extremely accurate even in the actual site as simulated. It was confirmed that this was an effective temperature adjustment method.

  As mentioned above, although embodiment and the Example of the substrate mounting apparatus and substrate temperature adjustment method of this invention were described, the content of this invention is not limited to description of embodiment and Example mentioned above. It will be apparent to those skilled in the art that various modifications and improvements can be made.

It is sectional drawing of the board | substrate mounting apparatus which concerns on embodiment of this invention, and the top view of a joining layer. It is a top view which shows distribution of the joining material in the joining layer which concerns on embodiment of this invention. It is sectional drawing which shows another aspect of the substrate mounting apparatus which concerns on embodiment of this invention. It is sectional drawing and a top view which show another aspect of the board | substrate mounting apparatus which concerns on embodiment of this invention. It is a graph which shows the result of having simulated the temperature distribution in the board | substrate mounting surface in the board | substrate mounting apparatus using the ceramic base material made from AlN which concerns on embodiment of this invention. It is a graph which shows the result of having simulated the temperature distribution in the board | substrate mounting surface in the board | substrate mounting apparatus using the ceramic base material made from Al2O3 which concerns on embodiment of this invention. It is a schematic sectional drawing of the apparatus figure which shows the evaluation method of the board | substrate mounting apparatus of Example 1 and 2 of this invention. It is a graph which shows the measurement result of substrate temperature distribution at the time of using the substrate mounting apparatus of Example 1 and 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate mounting apparatus 10 Ceramic base material 20 Bonding layer 30 Base plate 40. Electrostatic chuck electrode

Claims (14)

A plate-like ceramic substrate having a substrate mounting surface on one side;
A bonding layer formed on the other surface of the ceramic substrate,
The bonding layer is divided into a plurality of regions in a plane, and bonding materials having different thermal conductivities are arranged for each of the regions.   The substrate mounting apparatus according to claim 1, further comprising a base that is bonded to the other surface of the ceramic base material via the bonding layer.   The bonding layer is divided into two regions of a central portion and an outer peripheral portion thereof in the plane, the first bonding material is disposed as the bonding material in the central portion, and the outer peripheral portion as another bonding material, The substrate mounting apparatus according to claim 1, wherein a second bonding material having a thermal conductivity different from that of the first bonding material is disposed.   The substrate mounting apparatus according to claim 3, wherein the second bonding material has higher thermal conductivity than the first bonding material.   The substrate mounting apparatus according to any one of claims 1 to 4, wherein the bonding material includes an acrylic resin base material and a filler added to the base material.   The substrate mounting apparatus according to claim 1, further comprising an electrostatic chuck electrode embedded in the ceramic base material.   The substrate mounting apparatus according to claim 1, further comprising a resistance heating element embedded in the ceramic base material.   The substrate mounting apparatus according to claim 1, wherein the base includes a cooling structure.   The ceramic base material has a plurality of convex portions on the substrate placement surface, and a contact area between the placed substrate and each convex portion is different for each region in the substrate placement surface. The substrate mounting apparatus according to any one of claims 1 to 8.   The substrate mounting apparatus according to claim 9, wherein the contact area is larger in an outer peripheral region than in a central region in the substrate mounting surface.   The substrate mounting apparatus according to claim 10, wherein the contact area is larger in a central region than an outer peripheral region in the substrate mounting surface.   By adjusting the in-plane distribution of thermal conductivity in the bonding layer formed on the other surface of the ceramic substrate having the substrate mounting surface on one surface, the substrate mounted on the ceramic substrate is adjusted. A substrate temperature adjusting method comprising adjusting an in-plane temperature distribution. Adjustment of the in-plane distribution of thermal conductivity in the bonding layer is
A surface of the bonding layer is divided into a central portion and an outer peripheral portion thereof, a first bonding material is disposed in the central portion, and a second bonding having a different thermal conductivity from the first bonding material in the outer peripheral portion. The substrate temperature adjusting method according to claim 12, wherein the substrate temperature adjusting method is performed by arranging a material.   Furthermore, a plurality of protrusions are formed on the substrate mounting surface, and the contact area between the substrate to be mounted and each of the protrusions is adjusted depending on the location of the substrate to be mounted on the ceramic substrate. The substrate temperature adjusting method according to claim 12 or 13, wherein the in-plane temperature distribution is adjusted.