JP2003229238A - Ceramic substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic substrate which can prevent cracking due to impacts upon fitting to or removal from a supporting container, or cracking due to thermal stress, thermal shock or the like internally generated upon heating after fixed to the supporting container and rotational movement of the ceramic substrate. <P>SOLUTION: For the ceramic substrate in the interior or on the surface of which a conductor layer is formed, a cutout is formed in the ceramic substrate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a ceramic substrate such as a hot plate (ceramic heater), an electrostatic chuck, and a wafer prober which is used as an apparatus for manufacturing and inspecting semiconductors.

[0002]

2. Description of the Related Art In semiconductor manufacturing / inspection equipment including etching equipment and chemical vapor deposition equipment, heaters and wafer probers using metal base materials such as stainless steel and aluminum alloy have been used. Has been.

However, such a metal heater is
There were the following problems. First of all, because it is made of metal,
The thickness of the heater plate should be as thick as about 15 mm. This is because, in a thin metal plate, warping, distortion, etc. may not occur due to thermal expansion due to heating, and the silicon wafer placed on the metal plate may be damaged or tilted. However, when the thickness of the heater plate is increased, there is a problem that the weight of the heater becomes heavy and the heater becomes bulky.

Further, the temperature of a surface (hereinafter referred to as a heating surface) for heating an object to be heated such as a semiconductor wafer is controlled by changing the voltage and the amount of current applied to the resistance heating element. Since it is thick, the temperature of the heater plate does not quickly follow changes in voltage and current amount, and there is a problem that temperature control is difficult.

Therefore, in Japanese Patent Laid-Open No. 4-324276, aluminum nitride, which is a non-oxide ceramic having high thermal conductivity and high strength, is used as a substrate, and a resistance heating element and tungsten are used in the aluminum nitride substrate. Has been proposed, and a ceramic heater in which a dichrome wire is brazed to these as external terminals is proposed.

In such a ceramic heater, since a ceramic substrate having high mechanical strength even at high temperature is used, the thickness of the ceramic substrate can be reduced to reduce the heat capacity, and as a result, voltage and current can be reduced. The temperature of the ceramic substrate can be quickly made to follow the change in the amount.

Usually, in this type of ceramic heater, a temperature measuring element is attached to the surface or inside of the ceramic substrate,
After mounting this ceramic substrate on a metal support container via a resin heat insulating member, connect the wiring from the temperature measuring element and the wiring from the resistance heating element to the control device, and measure the temperature measured by the temperature measuring element. Voltage is applied to the resistance heating element based on
It controls the temperature of the ceramic substrate.

FIG. 13 is an exploded perspective view showing how a ceramic substrate of this type of ceramic heater is attached to a support container using a fixing member.

As shown in FIG. 13, a through hole 92 for mounting a fixing member 94 such as a bolt is provided in the vicinity of the peripheral edge of the ceramic substrate 91, and this fixing member 94 is provided.
Is inserted into the through hole 92 via the washer 93, and is screwed into the through hole 96 of the supporting container 95, whereby the ceramic substrate 91 is fixed to the supporting container 95. A heat insulating member made of resin or the like is usually interposed between the support container 95 and the ceramic substrate 91.

[0010]

However, when the ceramic substrate 91 having such a through hole 92 is used, the through hole 92 and the side surface of the ceramic substrate 91 are only a short distance, and thus the ceramic substrate 91. When the ceramic substrate 91 is attached or detached, or when the ceramic substrate 91 is heated after being attached, the ceramic substrate 91
There is a problem that cracks are likely to occur between the through hole 92 and the side surface of the ceramic substrate 91 due to thermal stress or the like or thermal shock.

When the ceramic substrate 91 is replaced, the fixing member 94 must be completely pulled out unless
There is a problem that the ceramic substrate 91 cannot be removed from the support container, and it takes time to attach and detach. Further, although the ceramic substrate 91 has a disk shape according to the shape of the silicon wafer, the ceramic substrate 91
When the through hole 92 is not formed in the ceramic substrate 9
Since 1 is a disc shape, it is easy to rotate.
There is also a problem that the wiring from the temperature measuring element or the resistance heating element connected to the ceramic substrate 91 is twisted and comes off.

The present invention has been made in view of the above-mentioned problems, and stress is applied to the ceramic substrate when the ceramic substrate is attached to or detached from the support container, or when the ceramic substrate is heated after attaching the ceramic substrate to the support container. The ceramic substrate does not crack even when subjected to thermal shock or thermal shock, and the ceramic substrate can be replaced in a short time. Moreover, even if the through hole is not formed in the ceramic substrate, the ceramic substrate It is an object of the present invention to provide a ceramic substrate that can prevent the rotation of the.

[0013]

The present invention is a ceramic substrate having a conductor layer formed inside or on the surface of the ceramic substrate, wherein the ceramic substrate is provided with a notch. It is a ceramic substrate.

According to the ceramic substrate of the present invention, the notch plays the role of the through hole 92 (see FIG. 13) in the conventional ceramic substrate 91, and the fixing member is inserted into the notch so that the ceramic substrate is formed. Can be fixed to a support container. Moreover, since it is a notch, unlike the conventional case, a crack does not occur due to an impact at the time of mounting or removing the ceramic substrate, and a crack occurs due to a stress or a thermal shock acting on the ceramic substrate. Nothing. Further, even if the fixing member is not completely pulled out from the ceramic substrate, the ceramic substrate can be removed from the supporting container by loosening the fixing member and then shifting the ceramic substrate, and the mounting and removal can be performed in a short time. . Moreover, since the rotation of the disk-shaped ceramic substrate can be prevented, there is no problem that the wiring from the temperature measuring element or the resistance heating element connected to the ceramic substrate is twisted and disengaged. Further, when the ceramic substrate has a temperature distribution, if the temperature distribution moves due to the rotation of the ceramic substrate, the variation in the performance of each silicon wafer remarkably increases. However, the present invention also has such a problem. Absent.

In the present invention, when a resistance heating element is formed inside or on the surface of the ceramic substrate, the ceramic substrate functions as a hot plate, and an electrostatic electrode is formed inside the ceramic substrate. If so, the ceramic substrate functions as an electrostatic chuck.

When a chuck top conductor layer is formed on the surface of the ceramic substrate and a guard electrode and / or a ground electrode is formed inside the ceramic substrate, the ceramic substrate serves as a wafer prober. Function.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The ceramic substrate of the present invention will be described below. The ceramic substrate of the present invention is a ceramic substrate in which a conductor layer is formed inside or on the surface of the ceramic substrate, and a notch is formed in the ceramic substrate.

First, a hot plate (also referred to as a ceramic heater) having a resistance heating element formed as a conductor layer on the surface or inside of a ceramic substrate will be described.
FIG. 1 is a bottom view schematically showing a ceramic heater which is an example of the ceramic substrate of the present invention, and FIG.
FIG. 2 is an exploded perspective view showing how the ceramic substrate of the ceramic heater shown in FIG. 1 is attached to a support container by using a fixing member, FIG. 3B is a partially enlarged plan view in the vicinity of a notch, and FIG. FIG. 3 is a partially enlarged sectional view schematically showing a part of the ceramic heater shown in FIG.

As shown in FIG. 1, the ceramic substrate 11
Are formed in a disk shape, and the ceramic substrate 11
Three notches 18 are formed on the periphery of the
On the bottom surface of the ceramic substrate 11, a resistance heating element 12a made of a bent circuit is formed in a portion close to the peripheral portion, and resistance heating elements 12b to 12d having a substantially concentric shape are formed in an inner portion thereof. By combining these circuits, the temperature on the heating surface 11a is designed to be uniform.

Further, the resistance heating elements 12a to 12d are formed with a metal coating layer 120 for preventing oxidation, and input / output terminal portions 13a to 13f are formed at both ends thereof. External terminals 17 are joined to 13a to 13f using solder or the like, as shown in FIG. Although not shown in FIG. 3, a socket or the like provided with wiring is connected to the external terminal 17 so that the external terminal 17 can be connected to a power source.

Although the resistance heating elements 12a to 12d are formed on the bottom surface of the ceramic substrate 11 shown in FIG. 1, the resistance heating elements may be formed inside the ceramic substrate. In this case, a through hole is provided immediately below the end of the resistance heating element, and a blind hole is provided so that the through hole is exposed, so that connection with the power supply can be achieved.

Further, a bottomed hole 14 for inserting the temperature measuring element is formed in the ceramic substrate 11, and a through hole 15 for inserting the lifter pin 16 is formed in a portion near the center. ing.

The lifter pin 16 is configured such that a silicon wafer 19 can be placed on the lifter pin 16 and moved up and down, whereby the silicon wafer 19 is transferred to a carrier machine (not shown) or the silicon wafer is transferred from the carrier machine. Wafer 19
The silicon wafer 19 is placed on the heating surface 11a of the ceramic substrate 11 and heated, or the silicon wafer 19 is supported and heated while being separated from the heating surface 11a by 50 to 2000 μm. Is able to.

A state in which a through hole or a recess is provided in the ceramic substrate 11, and a support pin having a pointed or hemispherical tip is inserted into the through hole or the recess, and then the support pin is slightly projected from the ceramic substrate 11. Alternatively, the silicon wafer 19 may be heated by being fixed at a distance of 50 to 2000 μm from the heating surface 11a by supporting the silicon wafer 19 with the support pins.

In the ceramic heater 10, as described above, the three notches 18 are formed in the ceramic substrate 1.
Although formed on the outer edge portion of 1, the number of the notches 18 is not limited to three as long as the ceramic substrate 11 can be firmly fixed to the support container, and even two may be provided.
It may be four or more. However, the ceramic substrate 11
In order to horizontally and stably fix it to the support container,
The notches 18 are preferably formed evenly on the outer edge of the ceramic substrate 11.

The size of the notch 18 is appropriately adjusted according to the size of the fixing member 130 and the ceramic substrate 11 to be used, and the width l is 1 to 10 mm and the depth d.
Is preferably in the range of 1 to 10 mm (Fig. 2
(See (b)). However, it is desirable that the shape of the notch 18 be formed by a curved surface such as a U-shape in plan view as shown in FIG. This is because if a notch such as a rectangle or a V shape is formed in a plan view, a corner is present in this notch, stress concentration occurs at that portion, and a crack is likely to occur.

As shown in FIG. 2, this ceramic substrate 1
When fixing 1 to the support container 150, the fixing member 130
Is inserted into the notch 18 through the washer 131, and is screwed into the threaded through hole 151 of the support container 150 to be fixed to the support container. Further, the ceramic substrate may be fixed by using bolts and nuts as the fixing member. Although not shown, a heat insulating member made of a heat resistant resin such as polyimide or an inorganic material such as ceramic is interposed between the ceramic substrate 11 and the supporting container as in the conventional case. Good.

The fixing member 130 is not particularly limited, and examples thereof include metal bolts. Washer 131
Is not particularly limited, for example, metal, heat-resistant resin,
Examples include ceramics such as alumina.

FIG. 4 (a) is an exploded perspective view schematically showing another embodiment of the ceramic substrate of the present invention, and FIG. 4 (b).
[Fig. 6] is a perspective view schematically showing another embodiment. In the present invention, as shown in FIG. 4A, the notch 280 may be formed by linearly notching a part of the side surface of the ceramic substrate 210. In this case, the through hole 251 formed in the support container 250 is not
The ceramic substrate 210 can be prevented from rotating by fitting the ceramic substrate 210 into the support container 250 so as to be exposed at the portion of 0 and inserting the rotation prevention pin 230 into the through hole 251. In addition, in this case, as shown in FIG. 5, the support container 2 is provided via a heat insulating member (not shown).
It is desirable to fit the ceramic substrate 210 in 50. Further, as shown in FIG. 4B, there may be a plurality of linear cutouts 380 on the ceramic substrate 310.

FIG. 5 is a sectional view schematically showing a state in which the ceramic substrate 11 having such a structure is attached to a supporting container having a structure different from that of FIG. The ceramic substrate 11 having the notches 18 is fitted into the upper portion of the cylindrical support container 62 via the heat insulating member 61, and the fixing member 130 is provided.
Is fixed to the support container 62 by inserting the notch 18 and the through hole of the heat insulating member 61 and screwing into the screw hole formed in the substrate receiving portion 62b of the support container 62.

As described above, the support container 62 has an annular substrate receiving portion 62b for fixing the ceramic substrate 11 inside the upper portion of the cylindrical main body 62a and a lower portion of the main body 62a. Toroidal bottom plate receiving part 6
2c is provided, and the bottom plate 64 is fixed to the bottom plate receiving portion 62c.

The ceramic substrate 11 has substantially the same structure as the ceramic heater 10 shown in FIG.
A conductive wire 66 having a T-shaped tip is connected to the end of each by soldering or the like, while a temperature measuring element 28 such as a thermocouple having a metal wire 63 is inserted into the bottomed hole 14 and a heat resistant resin is used. Etc. are used for sealing. The metal wire 63 and the conductive wire 66 are drawn out from a through hole 64 a formed in the bottom plate 64 of the support container 62. These wirings may be housed in an insulating member provided inside the support container and may be collectively pulled out from the through hole at the bottom. In this case, it is desirable to coat each wiring with an insulating coating member. The through hole 15 formed in the ceramic substrate 11
A guide tube 69 is provided immediately below the above so as to communicate with the through hole 15 so that a lifter pin (not shown) can be smoothly inserted.

As shown in FIG. 1, the ceramic substrate of the present invention may be fixed on the supporting container via a heat insulating member or the like, and as shown in FIG. It may be fitted through a member or the like.

Resistance heating element 1 formed on a ceramic substrate
As the pattern of 2, in addition to the combination of the concentric circle shape and the bent line shape shown in FIG. 1, a single pattern such as a concentric circle shape, a spiral shape, an eccentric circle shape, or a combination of these and the bent line shape is used. Can be mentioned.

In the ceramic heater, the number of circuits consisting of the resistance heating element is not particularly limited as long as it is 1 or more, but it is desirable to form a plurality of circuits in order to uniformly heat the heating surface. Particularly, a combination of a plurality of concentric circuits and a bent line circuit as shown in FIG. 1 is preferable. In the ceramic heater shown in FIG. 1, the resistance heating element is formed on the bottom surface,
The resistance heating element may be formed inside the ceramic substrate.

When the resistance heating element is formed inside the ceramic substrate, its forming position is not particularly limited.
It is preferable that at least one layer is formed at a position from the bottom surface of the ceramic substrate to 60% of its thickness. This is because the heat diffuses before reaching the heating surface, and the temperature of the heating surface becomes uniform.

When forming the resistance heating element inside or on the bottom surface of the ceramic substrate, it is preferable to use a conductor paste made of metal or conductive ceramic. That is, when the resistance heating element is formed inside the ceramic substrate, after forming the conductor paste layer on the green sheet, the green sheet is laminated and fired to produce the resistance heating element inside. On the other hand, when the resistance heating element is formed on the surface, the resistance heating element is usually manufactured by firing to form a ceramic substrate, then forming a conductor paste layer on the surface and firing.

The conductor paste is not particularly limited, but it is preferable that the conductor paste contains metal particles or a conductive ceramic in order to secure conductivity, and also contains a resin, a solvent, a thickener and the like.

As the metal particles, for example, noble metals (gold, silver, platinum, palladium), lead, tungsten, molybdenum, nickel and the like are preferable. These may be used alone or in combination of two or more. This is because these metals are relatively difficult to oxidize and have a resistance value sufficient to generate heat.

As the above-mentioned conductive ceramic, for example,
Examples thereof include tungsten and molybdenum carbides.
These may be used alone or in combination of two or more. The particle size of these metal particles or conductive ceramic particles is preferably 0.1 to 100 μm. This is because if it is less than 0.1 μm and too fine, it is easily oxidized, while if it exceeds 100 μm, it becomes difficult to sinter and the resistance value increases.

Even if the shape of the metal particles is spherical,
It may be flaky. When these metal particles are used, they may be a mixture of the above-mentioned spherical material and the above-mentioned scaly material. When the metal particles are scaly material, or a mixture of spherical material and scaly material, it becomes easier to hold the metal oxide between the metal particles and ensure the adhesion between the resistance heating element and the ceramic substrate. And the resistance value can be increased, which is advantageous.

The resin used for the conductor paste is
For example, an epoxy resin, a phenol resin, etc. are mentioned. Examples of the solvent include isopropyl alcohol and the like. Examples of the thickener include cellulose and the like.

When the conductor paste for the resistance heating element is formed on the surface of the ceramic substrate, metal oxide is added to the conductor paste in addition to the metal particles, and the metal particles and the metal oxide are sintered. It is preferable that Thus, by sintering the metal oxide together with the metal particles, the ceramic substrate and the metal particles can be brought into close contact with each other.

Although the reason why the adhesion with the ceramic substrate is improved by mixing the metal oxide is not clear, the surface of the metal particles or the surface of the ceramic substrate made of non-oxide is slightly oxidized. As a result, it is considered that the oxide film is formed, and the oxide films are sintered and integrated with each other through the metal oxide, and the metal particles and the ceramic adhere to each other. In addition, when the ceramic forming the ceramic substrate is an oxide, the surface is naturally made of an oxide, so that a conductor layer having excellent adhesion is formed.

Examples of the above metal oxide include, for example, oxidation.
Lead, zinc oxide, silica, boron oxide (B ₂ O₃ ), Al
Selected from the group consisting of Mina, Yttria and Titania
At least one is preferable. These oxides have resistance
Without increasing the resistance value of the heating element,
Because it can improve the adhesion to the Mick substrate.
It

The proportions of lead oxide, zinc oxide, silica, boron oxide (B ₂ O ₃ ), alumina, yttria, and titania are, when the total amount of metal oxides is 100 parts by weight, lead oxide is 1-10, silica 1-30, boron oxide 5-50, zinc oxide 20-70, alumina 1
-10, yttria is 1-50, and titania is 1-50, and it is preferable that the total is adjusted within a range not exceeding 100 parts by weight. By adjusting the amount of these oxides within these ranges, the adhesion to the ceramic substrate can be particularly improved.

The amount of the above metal oxide added to the metal particles is preferably 0.1% by weight or more and less than 10% by weight. Further, the area resistivity when the resistance heating element is formed using the conductor paste having such a configuration is preferably 1 to 45 mΩ / □.

When the sheet resistivity exceeds 45 mΩ / □, the amount of heat generated becomes too large with respect to the amount of applied voltage, and it is difficult to control the amount of heat generated by the ceramic substrate for semiconductor device having a resistance heating element on the surface. Because. In addition, when the addition amount of the metal oxide is 10% by weight or more, the area resistivity is 50%.
Since it exceeds mΩ / □, the amount of heat generated becomes too large, which makes temperature control difficult and reduces the uniformity of temperature distribution.

When the resistance heating element is formed on the surface of the ceramic substrate, it is preferable that a metal coating layer is formed on the surface portion of the resistance heating element. This is to prevent the internal metal sintered body from being oxidized and changing its resistance value.
The thickness of the metal coating layer formed is preferably 0.1 to 10 μm.

The metal used in forming the metal coating layer is not particularly limited as long as it is a non-oxidizing metal.
Specific examples include gold, silver, palladium, platinum, nickel and the like. These may be used alone or in combination of two or more. Of these, nickel is preferred. When the resistance heating element is formed inside the ceramic substrate, the surface of the resistance heating element is not oxidized, and thus the coating is unnecessary. The resistance heating element can be formed by using the conductor paste as described above, but can also be formed by embedding the metal wire inside the molded body. The ceramic substrate of the present invention can be used at 150 ° C. or higher, and preferably 200 ° C. or higher.

When the conductor layer formed on the ceramic substrate of the present invention is a resistance heating element, it can be used as a ceramic heater. The ceramic material forming this ceramic substrate is not particularly limited, and examples thereof include nitride ceramics, carbide ceramics, oxide ceramics, and the like.

Examples of the nitride ceramics include metal nitride ceramics such as aluminum nitride, silicon nitride, boron nitride and titanium nitride. Further, as the above-mentioned carbide ceramics, metal carbide ceramics,
For example, silicon carbide, zirconium carbide, titanium carbide,
Examples thereof include tantalum carbide and tungsten carbide.

Examples of the oxide ceramics include metal oxide ceramics such as alumina, zirconia, cordierite and mullite. These ceramics may be used alone or in combination of two or more.

Among these ceramics, nitride ceramics and carbide ceramics are preferable to oxide ceramics. This is because the thermal conductivity is high. Further, among the nitride ceramics, aluminum nitride is most suitable. This is because the highest thermal conductivity is 180 W / m · K.

The ceramic material may contain a sintering aid. Examples of the sintering aid include, for example,
Examples thereof include alkali metal oxides, alkaline earth metal oxides and rare earth oxides. Among these sintering aids,
CaO, Y ₂ O ₃ , Na ₂ O, Li ₂ O and Rb ₂ O are preferred. The content of these is 0.1 to 10% by weight.
Is preferred. It may also contain alumina.

The ceramic substrate according to the present invention preferably has a lightness of N4 or less based on JIS Z 8721. This is because those having such brightness are excellent in radiant heat amount and concealing property. Moreover, such a ceramic substrate enables accurate surface temperature measurement by a thermoviewer.

Here, the lightness N is such that the ideal lightness of black is 0, the ideal lightness of white is 10, and the brightness of the color is between the lightness of black and the lightness of white. Each color is divided into 10 so that the perception of is equal to each other, and is displayed by symbols N0 to N10. And the actual measurement is N0-N
The color chart corresponding to 10 is compared. In this case, the first decimal place is 0 or 5.

The ceramic substrate having such characteristics has 100 to 5000 p of carbon in the ceramic substrate.
It is obtained by containing pm. There are amorphous carbons and crystalline carbons. Amorphous carbons can suppress a decrease in volume resistivity of a ceramic substrate at high temperatures, and crystalline carbons have Since the decrease in thermal conductivity at high temperature can be suppressed, the type of carbon can be appropriately selected according to the purpose of the substrate to be manufactured.

Amorphous carbon is, for example, C, H or O.
It can be obtained by calcining a hydrocarbon consisting only of saccharides, preferably sugar, in air, and graphite powder or the like can be used as the crystalline carbon.
Carbon can be obtained by thermally decomposing an acrylic resin in an inert atmosphere and then applying heat and pressure. By changing the acid value of this acrylic resin, crystalline (non-crystalline) properties can be obtained. The degree of can be adjusted.

The shape of the ceramic substrate is preferably a disk shape, and the diameter thereof is preferably 200 mm or more, 250
The optimum value is mm or more. This is because the disk-shaped ceramic substrate of the present invention is required to have a uniform temperature, but a substrate having a larger diameter tends to have a non-uniform temperature. The thickness of the ceramic substrate is preferably 50 mm or less, more preferably 20 mm or less. Further, 1 to 5 mm is optimal. This is because if the thickness is too thin, warping tends to occur when heating at high temperature, while if it is too thick, the heat capacity becomes too large and the temperature raising / lowering characteristics deteriorate.

The porosity of the ceramic substrate is preferably 0 or 5% or less. The porosity is measured by the Archimedes method. This is because it is possible to suppress the decrease in thermal conductivity at high temperatures and the occurrence of warpage.

In the present invention, a thermocouple can be embedded in the ceramic substrate if necessary. The temperature of the resistance heating element is measured with a thermocouple, and the voltage,
This is because the temperature can be controlled by changing the amount of current.

The size of the joining portion of the metal wires of the thermocouple is preferably equal to or larger than the wire diameter of each metal wire and 0.5 mm or less. With such a configuration, the heat capacity of the joint portion is reduced, and the temperature is converted into a current value accurately and quickly. Therefore, the temperature controllability is improved and the temperature distribution on the heating surface of the wafer is reduced. Examples of the thermocouple include J
As listed in IS-C-1602 (1980),
Examples include K type, R type, B type, E type, J type, and T type thermocouples.

The above-mentioned ceramic heater is a device in which only a resistance heating element is provided on the surface or inside of the ceramic substrate, and by this, an object to be heated such as a silicon wafer can be heated to a predetermined temperature. Other specific devices for the ceramic substrate of the present invention include, for example, an electrostatic chuck, a wafer prober, a susceptor, and the like.

When the conductor layer formed inside the ceramic substrate of the present invention is an electrostatic electrode, this ceramic substrate functions as an electrostatic chuck. FIG. 6A is a vertical sectional view schematically showing the electrostatic chuck, and FIG.
It is the sectional view on the AA line of the electrostatic chuck shown to (a).

In this electrostatic chuck 20, chuck positive and negative electrode layers 22 and 23 are embedded inside a ceramic substrate 21, and a ceramic dielectric film 25 is formed on the electrodes. A resistance heating element 24 is provided inside the ceramic substrate 21 so that the silicon wafer 19 can be heated. The ceramic substrate 21
If necessary, an RF electrode may be embedded therein.

Further, as shown in (b), the electrostatic chuck 20 is usually formed in a circular shape in plan view, and the semi-arcuate portion 22a shown in FIG.
And a chuck positive electrode electrostatic layer 22 including a comb tooth portion 22b,
Similarly, the chuck negative electrode electrostatic layer 23 composed of the semi-circular portion 23a and the comb-tooth portion 23b is provided with the comb-tooth portions 22b and 23b.
Are arranged to face each other.

When this electrostatic chuck is used, the positive and negative sides of a DC power source are connected to the chuck positive electrode electrostatic layer 22 and the chuck negative electrode electrostatic layer 23, respectively, and a DC voltage is applied. As a result, the semiconductor wafer placed on this electrostatic chuck is electrostatically adsorbed.

7 and 8 are horizontal sectional views schematically showing electrostatic electrodes in another electrostatic chuck.
In the electrostatic chuck 70 shown in FIG. 7, a semi-circular chuck positive electrode electrostatic layer 72 and a chuck negative electrode electrostatic layer 73 are formed inside a ceramic substrate 71. In the electrostatic chuck 80 shown in FIG. Inside, the chuck positive electrode electrostatic layers 82a and 82b and the chuck negative electrode electrostatic layers 83a and 83b, each having a shape obtained by dividing a circle into four, are formed. Further, the two chuck positive electrode electrostatic layers 82a and 82b and the two chuck negative electrode electrostatic layers 83a and 83b are formed so as to intersect with each other.

When forming an electrode in which a circular electrode or the like is divided, the number of divisions is not particularly limited and may be 5 or more, and the shape thereof is not limited to a fan shape.

Next, when a chuck top conductor layer is provided on the surface of the ceramic substrate of the present invention and a guard electrode or a ground electrode is formed inside as a conductor layer, the ceramic substrate functions as a wafer prober. Figure 9
It is sectional drawing which showed typically the wafer prober which is an example of the ceramic substrate of this invention, FIG. 10 is the top view, FIG. 11 is the sectional view on the AA line in the wafer prober shown in FIG. Is.

In this wafer prober 101, concentric grooves 7 are formed on the surface of the ceramic substrate 3 which is circular in plan view, and a plurality of suction holes 8 for sucking the silicon wafer are formed in part of the grooves 7. The chuck top conductor layer 2 for connecting to the electrodes of the silicon wafer is formed in a circular shape on most of the ceramic substrate 3 including the groove 7.

On the other hand, on the bottom surface of the ceramic substrate 3, there is provided a resistance heating element 41 in which a concentric pattern and a bent line pattern as shown in FIG. 1 are combined in order to control the temperature of the silicon wafer. External terminals are connected and fixed to the terminal portions formed at both ends of the resistance heating element 41. Further, inside the ceramic substrate 3, guard electrodes 5 and ground electrodes 6 having a lattice shape as shown in FIG. 11 are provided in order to remove stray capacitors and noise. The rectangular electrode non-forming portion 52 is provided on the guard electrode 5 in order to bond the upper and lower ceramic substrates sandwiching the guard electrode 5 to each other.

In the wafer prober having such a structure, after mounting a silicon wafer having an integrated circuit formed thereon, a probe card having tester pins is pressed against this silicon wafer, and a voltage is applied while heating and cooling. hand,
A continuity test can be performed to test whether the circuit works properly.

Next, a method for manufacturing a ceramic heater will be described as an example of the method for manufacturing a ceramic substrate of the present invention. First, a method for manufacturing a ceramic heater in which the resistance heating element 12 is formed on the bottom surface of the ceramic substrate 11 shown in FIG. 1 will be described.

(1) Manufacturing process of ceramic substrate A slurry is prepared by adding a sintering aid such as yttria or a binder to the above-described nitride ceramic such as aluminum nitride, if necessary, and then spray drying this slurry. And the like, and the granules are put into a mold or the like to be pressed into a plate shape to prepare a green shaped body. At this time, carbon may be contained.

Next, if necessary, a bottomed hole 14 for embedding a temperature measuring element such as a through hole 15 for inserting a lifter pin 16 for supporting a silicon wafer or a thermocouple into the molded body. A portion that becomes the cutout 18 that penetrates the fixing member 130, and the like are formed. After firing, a through hole 15, a bottomed hole 14, a notch 18, etc. may be formed in the manufactured ceramic substrate using a drill, a cutting member, or the like.

Next, this green body is heated, fired and sintered to produce a ceramic plate-like body. After that, the ceramic substrate 11 is manufactured by processing it into a predetermined shape, but it may have a shape that can be used as it is after firing. By heating and firing while applying pressure, it becomes possible to manufacture the ceramic substrate 11 having no pores. The heating and firing may be carried out at a sintering temperature or higher, but in the case of a nitride ceramic, it is 1000 to 2500 ° C.

(2) Step of Printing Conductor Paste on Ceramic Substrate Generally, the conductor paste is a highly viscous fluid containing metal particles, resin and solvent. This conductor paste is printed on the portion where the resistance heating element is to be provided by screen printing or the like to form a conductor paste layer.
Further, since the resistance heating element needs to keep the temperature of the entire ceramic substrate uniform, it is preferable to print the resistance heating element in a pattern in which concentric circles and curved lines are combined as shown in FIG. The conductor paste layer is used for the resistance heating element 12 after firing.
It is preferable that the cross section is rectangular and has a flat shape.

(3) Firing of Conductor Paste The conductor paste layer printed on the bottom surface of the ceramic substrate 11 is heated and fired to remove the resin and the solvent, and the metal particles are sintered and baked on the bottom surface of the ceramic substrate 11.
The resistance heating element 12 is formed. The temperature for heating and firing is 500
The temperature is preferably 1000 ° C. When the above-mentioned metal oxide is added to the conductor paste, the metal particles, the ceramic substrate and the metal oxide are sintered and integrated, so that the adhesion between the resistance heating element and the ceramic substrate is improved.

(4) Formation of metal coating layer It is desirable to provide a metal coating layer on the surface of the resistance heating element 12. The metal coating layer can be formed by electrolytic plating, electroless plating, sputtering, etc., but in consideration of mass productivity, electroless plating is most suitable.

(5) Attachment of terminals and the like External terminals for connection to the power source are attached to the ends of the pattern of the resistance heating element 12 by using solder or the like. Further, a thermocouple is inserted into the bottomed hole 14 and sealed with a heat resistant resin such as polyimide or ceramics to form the ceramic heater 10. In addition,
In the above method, when the granules are put into a mold to form a molded body, a resistance heating element can be formed inside the ceramic substrate by embedding a metal wire inside.

When manufacturing the above-mentioned ceramic heater, an electrostatic chuck can be manufactured by providing an electrostatic electrode inside the ceramic substrate, and a chuck top conductor layer is provided on the heating surface so that the inside of the ceramic substrate is A wafer prober can be manufactured by providing a guard electrode and a ground electrode on the substrate.

When the electrodes are provided inside the ceramic substrate, a metal foil or the like may be embedded inside the ceramic substrate. When forming a conductor layer on the surface of a ceramic substrate, a sputtering method or a plating method can be used, and these may be used together.

Next, a method of manufacturing a ceramic heater having a resistance heating element formed inside a ceramic substrate will be described with reference to FIG. (1) Ceramic Substrate Manufacturing Step First, a powder of nitride ceramic is mixed with a binder, a solvent and the like to prepare a paste, and a green sheet is manufactured using this paste. As the above-mentioned ceramic powder, aluminum nitride or the like can be used, and if necessary,
A sintering aid such as yttria may be added.

The binder is preferably at least one selected from acrylic binders, ethyl cellulose, butyl cellosolve, and polyvinyl alcohol.
Further, the solvent is preferably at least one selected from α-terpineol and glycol.

The paste obtained by mixing these is formed into a sheet by the doctor blade method to obtain a green sheet 5.
Create 0. The thickness of the green sheet 50 is 0.1
5 mm is preferable. Next, the obtained green sheet 50
In addition, if necessary, a part to be a through hole for inserting a lifter pin for supporting a silicon wafer, a part to be a bottomed hole for embedding a temperature measuring element such as a thermocouple, a notch for inserting a fixing member. 380, which is a through hole for connecting the resistance heating element to an external terminal outside.
And so on. The above-mentioned processing may be performed after forming a green sheet laminate described below.

(2) Step of Printing Conductor Paste on Green Sheet A conductor paste containing a metal paste or a conductive ceramic is printed on the green sheet 50 to form a conductor paste layer 320. These conductive pastes contain metal particles or conductive ceramic particles. The average particle size of tungsten particles or molybdenum particles is
0.1-5 micrometers is preferable. If the average particle size is less than 0.1 μm or exceeds 5 μm, it is difficult to print the conductor paste.

As such a conductor paste, for example, 85 to 87 parts by weight of metal particles or conductive ceramic particles; 1.5 to 10 parts by weight of at least one binder selected from acrylic, ethyl cellulose, butyl cellosolve, and polyvinyl alcohol are used. And a composition (paste) in which 1.5 to 10 parts by weight of at least one solvent selected from α-terpineol and glycol is mixed.

(3) Laminating step of green sheet The green sheet 50 on which the conductor paste is not printed is
The green sheets 50 on which the conductor paste is printed are laminated on the upper and lower sides (FIG. 12A). At this time, the number of green sheets 50 stacked on the upper side is made larger than the number of green sheets 50 stacked on the lower side, and the formation position of the resistance heating element is eccentric in the direction of the bottom surface side. Specifically, the number of stacked upper green sheets 50 is preferably 20 to 50, and the number of stacked lower green sheets 50 is preferably 5 to 20.

(4) Firing Step of Green Sheet Laminated Body The green sheet laminated body is heated and pressed to sinter the green sheet 50 and the conductor paste layer 320 inside (FIG. 12B). The heating temperature is 1000 to 2000
C. is preferred, and the pressure applied is preferably 10 to 20 MPa. The heating is performed in an inert gas atmosphere. As the inert gas, for example, argon, nitrogen or the like can be used.

After baking, a bottomed hole or the like for inserting the temperature measuring element may be provided. The bottomed holes and the like can be formed by polishing the surface and then performing blasting such as drilling or sandblasting. Also, a through hole 38 for connecting to the internal resistance heating element 32.
A blind hole 37 is formed to expose the
(C)), the external terminal 17 is inserted into the bag hole 37, heated and reflowed to connect the external terminal 17 (FIG. 12 (d)). The heating temperature is 9 for soldering.
0 to 450 ° C. is preferable, and 900 to 1100 ° C. is preferable in the case of treatment with a brazing material. Further, a thermocouple as a temperature measuring element is sealed with a heat resistant resin or the like to form a ceramic heater.

In this ceramic heater, various operations are performed while heating or cooling the silicon wafer or the like after mounting the silicon wafer or the like on the ceramic heater or holding the silicon wafer or the like by the support pins. be able to.

When manufacturing the above-mentioned ceramic heater, an electrostatic chuck can be manufactured by providing an electrostatic electrode inside the ceramic substrate, and a chuck top conductor layer is provided on the heating surface so that the inside of the ceramic substrate is A wafer prober can be manufactured by providing a guard electrode and a ground electrode on the substrate.

When the electrodes are provided inside the ceramic substrate, the conductor paste layer may be formed on the surface of the green sheet as in the case of forming the resistance heating element. When forming a conductor layer on the surface of a ceramic substrate, a sputtering method or a plating method can be used, and these may be used together.

The present invention will be described in more detail below.

EXAMPLES Example 1 Manufacturing of Ceramic Heater (See FIG. 1) (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1 μm), yttrium oxide (Y ₂ O)
₃ : Spray dried a composition consisting of yttria, 4 parts by weight of average particle size 0.4 μm), 12 parts by weight of acrylic resin binder and alcohol to prepare granular powder.

(2) Next, the granular powder was put into a mold and molded into a flat plate to obtain a green molded body (green).

(3) The green body after the processing is hot-pressed at a temperature of 1800 ° C. and a pressure of 20 MPa,
An aluminum nitride sintered body having a thickness of 3 mm was obtained. next,
A disk body having a diameter of 210 mm was cut out from this plate body to obtain a ceramic plate body (ceramic substrate 11). Next, the plate-shaped body is subjected to drilling and cutting with a through-hole to insert a lifter pin, a through-hole 15 to insert a support pin supporting a silicon wafer, and a bottomed hole 14 to embed a thermocouple. (Diameter: 1.1 mm, depth:
2mm) and U-shaped notch 18 (width: 5m
m, depth: 10 mm) was formed. (4) A conductor paste was printed by screen printing on the bottom surface of the sintered body obtained in (3) above. The print pattern is shown in Figure 1.
The pattern is a combination of the concentric circle shape and the bent line shape as shown in FIG. As the conductor paste, Solbest PS603D manufactured by Tokuriki Kagaku Kenkyusho, which is used for forming through holes of printed wiring boards, was used.

This conductor paste is a silver-lead paste, and based on 100 parts by weight of silver, lead oxide (5% by weight), zinc oxide (55% by weight), silica (10% by weight), boron oxide (25% by weight). % By weight) and 7.5% by weight of a metal oxide composed of alumina (5% by weight). Also,
The silver particles had an average particle size of 4.5 μm and were flaky.

(5) Next, the sintered body on which the conductor paste is printed is heated and fired at 780 ° C. to obtain silver in the conductor paste.
Lead was sintered and baked on the sintered body to form a resistance heating element. The silver-lead resistance heating element 12 had a thickness of 5 μm, a width of 2.4 mm, and an area resistivity of 7.7 mΩ / □ in the vicinity of its terminal portion. (6) Next, in an electroless nickel plating bath consisting of an aqueous solution containing 80 g / l of nickel sulfate, 24 g / l of sodium hypophosphite, 12 g / l of sodium acetate, 8 g / l of boric acid and 6 g / l of ammonium chloride, the above ( The sintered body prepared in 5) is dipped, and a thickness of 1 is formed on the surface of the silver-lead resistance heating element 12.
A metal coating layer 120 (nickel layer) having a thickness of μm was deposited.

(7) A silver-lead solder paste (manufactured by Tanaka Kikinzoku Co., Ltd.) was printed by screen printing on the terminal portion for ensuring the connection with the power source to form a solder layer. Then,
Place the Kovar external terminal 17 on the solder layer, and
Reflow was performed by heating at 20 ° C., and the external terminal 17 was attached to the terminal portion of the resistance heating element. (8) A thermocouple for temperature control was inserted into the bottomed hole, filled with polyimide resin, and cured at 190 ° C. for 2 hours to obtain a ceramic heater 10 (see FIG. 1).

Example 2 Production of Electrostatic Chuck (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corp., average particle size 1.1 μm), yttria (average particle size 0.1.
4 μm) 4 parts by weight, 12 parts by weight of an acrylic resin binder, 0.5 parts by weight of a dispersant, and 53 parts by weight of an alcohol consisting of 1-butanol and ethanol are mixed, and a composition is formed by a doctor blade method. Thus, a green sheet having a thickness of 0.47 mm was obtained. (2) Next, this green sheet was dried at 80 ° C. for 5 hours and then punched to form through holes for through holes for connecting the resistance heating element and external terminals.

(3) 100 parts by weight of tungsten carbide particles having an average particle diameter of 1 μm and an acrylic binder of 3.0
By weight, 3.5 parts by weight of the α-terpineol solvent and 0.3 parts by weight of the dispersant were mixed to prepare a conductive paste A.
Further, 100 parts by weight of tungsten particles having an average particle diameter of 3 μm, 1.9 parts by weight of an acrylic binder, 3.7 parts by weight of an α-terpineol solvent, and 0.2 parts by weight of a dispersant were mixed to prepare a conductive paste B. .

(4) The conductive paste A was printed on the surface of the green sheet by a screen printing method to form a resistance heating element. The print pattern was the same as in Example 1 in which concentric circles and bent lines were combined. Further, a conductor paste layer having an electrostatic electrode pattern having the shape shown in FIG. 6 was formed on another green sheet.

Further, the through holes for through holes for connecting the external terminals were filled with the conductive paste B. The electrostatic electrode pattern is composed of comb-teeth electrodes (22b, 23b), and 22b, 23b are connected to 22a, 23a, respectively (see FIG. 6 (b)).

34 green sheets on which the tungsten paste is not printed are provided on the upper side (heating side) and 13 on the lower side (bottom side).
A green sheet on which a conductor paste layer composed of an electrostatic electrode pattern is printed is laminated on top of that, and two green sheets on which a tungsten paste is not printed are further laminated thereon, and these are placed at 130 ° C. and 8 MPa. It pressure-bonded by the pressure of and the laminated body was formed.

(5) Next, the obtained laminated body was degreased in nitrogen gas at 600 ° C. for 5 hours, and then hot pressed for 3 hours at 1890 ° C. and a pressure of 15 MPa to give a thickness of 3 m.
Thus, an aluminum nitride plate-shaped body of m was obtained. This is diameter 230
mm disk-shaped, and a resistance heating element 32 having a thickness of 5 μm, a width of 2.4 mm and an area resistivity of 7.7 mΩ / □, and a chuck positive electrode electrostatic layer 22 having a thickness of 6 μm and a chuck negative electrode. A plate-shaped body made of aluminum nitride having the electrostatic layer 23 was formed.

(6) Ceramic substrate 2 obtained in (5) above
After polishing No. 1 with a diamond grindstone, a mask was placed on the surface, and a bottomed hole (diameter: 1.2 mm, depth 2.0 m for a thermocouple) was formed on the surface by blasting with SiC or the like.
m) and a peripheral notch (maximum distance from side surface: 5 mm).

(7) Further, the portion where the through hole is formed is cut out to form a bag hole, and the bag hole is made of Ni-A.
Using gold solder made of u, heating reflow was performed at 700 ° C. to connect external terminals made of Kovar.

(8) Next, a plurality of thermocouples for temperature control were embedded in the bottomed holes, and the manufacture of the electrostatic chuck having the resistance heating element having the pattern shown in FIG. 1 was completed.

Example 3 Manufacturing of Wafer Prober (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corp., average particle size 1.1 μm), yttria (average particle size 0.
4 μm) 4 parts by weight, 12 parts by weight of an acrylic resin binder, 0.5 parts by weight of a dispersant, and 53 parts by weight of an alcohol consisting of 1-butanol and ethanol are mixed, and a composition is formed by a doctor blade method. Thus, a green sheet having a thickness of 0.47 mm was obtained. (2) Next, after drying this green sheet at 80 ° C. for 5 hours, punching was performed to provide through-hole through holes for connecting electrodes and external terminals.

(3) 100 parts by weight of tungsten carbide particles having an average particle size of 1 μm and an acrylic binder of 3.0
By weight, 3.5 parts by weight of the α-terpineol solvent and 0.3 parts by weight of the dispersant were mixed to prepare a conductive paste A.
Further, 100 parts by weight of tungsten particles having an average particle diameter of 3 μm, 1.9 parts by weight of an acrylic binder, 3.7 parts by weight of an α-terpineol solvent, and 0.2 parts by weight of a dispersant were mixed to prepare a conductive paste B. .

(4) The conductive paste A was printed on the surface of the green sheet by screen printing to form a grid-like print layer for guard electrodes and a print layer for ground electrodes (see FIGS. 9 and 11). . Further, the through-hole through-hole for connecting the external terminal was filled with the conductive paste B to form a through-hole filling layer. Then, 50 sheets of the green sheet on which the conductive paste is printed and the green sheet on which the conductive paste is not printed are stacked, and 1
They were integrated at 30 ° C. and a pressure of 8 MPa.

(5) The integrated laminated body is heated at 600 ° C. for 5 hours.
After degreasing for 1 hour, hot pressing was performed at 1890 ° C. and a pressure of 15 MPa for 3 hours to obtain an aluminum nitride plate-shaped body having a thickness of 3 mm. This plate-shaped body was cut into a circular shape having a diameter of 230 mm to obtain a ceramic substrate. The size of the through hole was 0.2 mm in diameter and 0.2 mm in depth. The thickness of the guard electrode 5 and the ground electrode 6 is 10
μm, the formation position of the guard electrode 5 in the thickness direction of the sintered body is
1mm from the chuck surface, while the ground electrode 6
The formation position of the sintered body in the thickness direction is 1.
It was 2 mm.

(6) After polishing the ceramic substrate obtained in (5) above with a diamond grindstone, a mask is placed,
By blasting with SiC or the like, a bottomed hole for attaching a thermocouple and a groove 7 for wafer adsorption (width 0.5 m
m, depth 0.5 mm), and U-shaped notches (width: 2.5 mm, depth: 5 mm) were formed in the peripheral portion.

(7) Further, a conductive paste was printed on the back surface (bottom surface) facing the chuck surface on which the groove 7 was formed to form a conductor paste layer for a resistance heating element. As this conductive paste, Solbest PS603D manufactured by Tokuriki Kagaku Kenkyusho, which is used for forming through holes of printed wiring boards, was used. That is, this conductive paste is a silver / lead paste and contains a metal oxide composed of lead oxide, zinc oxide, silica, boron oxide, and alumina (the weight ratio of each is 5/55/10/25/5). 7. For the amount of silver
It contains 5% by weight. As the silver in this conductive paste, a flaky one having an average particle diameter of 4.5 μm was used.

(8) A ceramic substrate (ceramic substrate) 78 having a circuit formed by printing a conductive paste on the bottom surface is formed.
By heating and firing at 0 ° C., silver and lead in the conductive paste were sintered and baked on a ceramic substrate to form a resistance heating element. The pattern of the resistance heating element was the same as that of Example 1 in which the concentric circular shape and the bent linear shape were combined (see FIG. 1). Next, this ceramic substrate is dipped in an electroless nickel plating bath made of an aqueous solution containing 30 g / l of nickel sulfate, 30 g / l of boric acid, 30 g / l of ammonium chloride, and 60 g / l of Rochelle salt to remove the conductive paste. The resistance heating element is thickened by further depositing a nickel layer having a thickness of 1 μm and a boron content of 1% by weight or less on the surface of the resistance heating element.
Heat treatment was performed at 0 ° C. for 3 hours. The resistance heating element 41 including the nickel layer thus obtained had a thickness of 5 μm, a width of 2.4 mm, and an area resistivity of 7.7 mΩ / □.

(9) Ti, Mo, and Ni layers were sequentially laminated on the chuck surface having the groove 7 by a sputtering method. This sputtering uses SV-4540 manufactured by Nippon Vacuum Technology Co., Ltd. as an apparatus, atmospheric pressure: 0.6 Pa, temperature: 100 ° C., electric power: 200 W, processing time: 30 seconds to 1
The sputtering time was adjusted according to each metal to be sputtered. The film obtained had a Ti content of 0.3 μm and a Mo content of 2 μm from the X-ray fluorescence spectrometer image.
m and Ni were 1 μm.

(10) Using the ceramic substrate obtained in (9) above, nickel sulfate 30 g / l, boric acid 30 g / l,
Ammonium chloride 30g / l, Rochelle salt 60g / l
The nickel layer (thickness 7 μm) having a boron content of 1% by weight or less is deposited on the surface of the groove 7 formed on the chuck surface by immersing in an electroless nickel plating bath made of an aqueous solution containing It heat-processed at 3 degreeC. Furthermore, 93 ° C. was applied to an electroless gold plating solution containing 2 g / l of potassium gold cyanide, 75 g / l of ammonium chloride, 50 g / l of sodium citrate, and 10 g / l of sodium hypophosphite on the ceramic substrate surface (chuck surface side). Then, the chuck top conductor layer 2 was formed by dipping for 1 minute under the above condition and further laminating a gold plating layer having a thickness of 1 μm on the nickel plating layer on the chuck surface side of the ceramic substrate.

(11) Next, the air suction hole 8 that escapes from the groove 7 to the back surface is drilled and punched, and a blind hole for exposing the through holes 46 and 47 is provided. Ni-Au alloy (Au 81.5 wt%, Ni18.
4 wt%, 0.1 wt% of impurities) was used, and the solder was heated and reflowed at 970 ° C. to connect external terminals made of Kovar. Further, an external terminal made of Kovar was formed on the resistance heating element 41 via a solder alloy (tin 9 / lead 1).
(12) For temperature control, a plurality of thermocouples were embedded in the bottomed holes (not shown), and the production of the heater with a wafer prober was completed.

Comparative Example 1 A ceramic heater was manufactured in the same manner as in Example 1 except that a through hole (diameter: 10 mm) was formed at the same position without forming a notch (see FIG. 13). The portion of the inner wall of the through hole closest to the side surface was 5 mm away from the side surface of the ceramic substrate.

The ceramic heater and wafer prober manufactured in Examples 1 and 3 and Comparative Example 1 were placed on a stainless steel support container having the structure shown in FIG. The ceramic heater and wafer prober are supported by inserting the bolt (fixing member) made of tungsten through the washer made of tungsten into the notch and the through hole of the heat insulating member, and further screwing the screw into the screw hole of the supporting container. It was fixed in the container. Regarding the electrostatic chuck of Example 2, as shown in FIG. 4, after the ceramic substrate was fitted in the support container, the rotation prevention pin was inserted into the through hole,
Fixed

The ceramic heaters of Examples 1 to 3 and Comparative Example 1 were energized and heated to 300 ° C.,
After repeating the process of keeping this temperature for 1 hour and then cooling it 100 times, each ceramic substrate was removed from the support container, and the presence or absence of cracks was observed.

As a result, cracks were not observed at all in the ceramic substrates according to Examples 1 to 3, but with respect to the ceramic substrate according to Comparative Example 1, the side surface from the through hole formed near the outer edge of the ceramic substrate was observed. There was a crack toward.

[0125]

Since the ceramic substrate according to the present invention has the above-mentioned structure, it does not cause cracks due to impact when it is attached to or detached from the support container, and the support container is not attached. At the time of heating after fixing to No. 3, cracks do not occur due to thermal stress or thermal shock generated inside. Further, since the ceramic substrate can be removed without completely pulling out the fixing member, it is possible to attach or remove the ceramic substrate in a short time.
Further, since the rotation of the ceramic substrate can be prevented, it is possible to prevent the wiring or the like connected to the ceramic substrate from being twisted or dropped.

[Brief description of drawings]

FIG. 1 is a bottom view schematically showing a ceramic heater which is an example of a ceramic substrate of the present invention.

2 (a) is an exploded perspective view showing how the ceramic substrate shown in FIG. 1 is attached to a support container using a fixing member, and FIG. 2 (b) is a partially enlarged view schematically showing the vicinity of a notch. It is a top view.

FIG. 3 is a partially enlarged cross-sectional view schematically showing a part of the ceramic heater shown in FIG.

FIG. 4 (a) is a perspective view schematically showing another embodiment of the ceramic substrate of the present invention, and FIG. 4 (b) further includes
It is a perspective view which shows another embodiment typically.

FIG. 5 is a cross-sectional view schematically showing a state in which the ceramic substrate according to the present invention is attached to another supporting container.

6A is a vertical cross-sectional view schematically showing an electrostatic chuck, and FIG. 6B is a sectional view of the electrostatic chuck shown in FIG.
FIG.

FIG. 7 is a horizontal sectional view schematically showing another example of the electrostatic electrode embedded in the electrostatic chuck.

FIG. 8 is a horizontal sectional view schematically showing still another example of the electrostatic electrode embedded in the electrostatic chuck.

FIG. 9 is a sectional view schematically showing a wafer prober which is an example of the ceramic substrate of the present invention.

FIG. 10 is a plan view of the wafer prober shown in FIG.

FIG. 11 is an AA in the wafer prober shown in FIG.
It is a line sectional view.

12 (a) to 12 (d) are cross-sectional views schematically showing an example of a method for manufacturing a ceramic heater according to the present invention.

FIG. 13 is an exploded perspective view showing how a ceramic substrate of a conventional ceramic heater is attached to a support container using a fixing member.

[Explanation of symbols]

2 Chuck top conductor layer 3, 11, 21, 71, 81 Ceramic substrate 5 Guard electrode 6 ground electrode 7 groove 8 suction holes 10 Ceramic heater 11a heating surface 11b bottom 12a to 12d, 24, 32, 41 Resistance heating element 13a to 13f Terminal part 14 Bottomed hole 15 through holes 16 lifter pins 17 External terminal 18 notches 19 Silicon wafer 20, 70, 80 Electrostatic chuck 22, 72, 82a, 82b Chuck positive electrode electrostatic layer 23, 73, 83a, 83b Chuck negative electrode electrostatic layer 25 Ceramic Dielectric Film 28 Temperature measuring element 37 bag holes 38 through hole 52 Electrode non-formed part 61 Thermal insulation member 62 Support container 62a main body 62b Substrate receiving part 62c Bottom plate receiving part 63 metal wire 64 bottom plate 64a through hole 65 Refrigerant introduction pipe 66 Conductive wire 69 Guide tube 120 metal coating layer 130 fixing member 131 washers 150 support containers

Continued front page    F-term (reference) 3K034 AA10 BA02 BB06 BB14 CA02                       GA10 JA02                 3K092 PP20 QA05 RF11 TT19 VV02                       VV03 VV31 VV40                 4M106 AA01 BA01 DD30                 5F045 AA03 BB20 DP01 EK09 EM05

Claims (4)

[Claims] 1. A ceramic substrate in which a conductor layer is formed inside or on the surface of the ceramic substrate, wherein a notch is formed in the ceramic substrate. 2. The ceramic substrate according to claim 1, wherein a resistance heating element is formed inside or on the surface of the ceramic substrate, and the ceramic substrate functions as a hot plate. 3. The ceramic substrate according to claim 1, wherein an electrostatic electrode is formed inside the ceramic substrate, and the ceramic substrate functions as an electrostatic chuck. 4. A chuck top conductor layer is formed on the surface of the ceramic substrate, a guard electrode and / or a ground electrode is formed inside the ceramic substrate, and the ceramic substrate functions as a wafer prober. 1. The ceramic substrate according to 1.