JP2002329567A - Ceramic substrate and method of manufacturing junction body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic substrate having high corrosion resistance without being corroded to the depths even if it is exposed to a reactive gas or halogen gas over a long period of time and preventing the coming off of ceramic particles from the surface and the generation of particles caused by attaching of the ceramic particles to a treating substance such as a silicon wafer even when the treating substance is placed on the surface and treated by etching for example. SOLUTION: In the ceramic substrate in which a conductor is installed on the surface or the inside, the ceramic substrate is made of Y2 O3 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate which is used for a hot plate (ceramic heater), an electrostatic chuck, a susceptor, etc., and has a conductor provided therein. The present invention relates to a method for manufacturing a joined body in which ceramic bodies are joined.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor manufacturing / inspection apparatus including an etching apparatus and a chemical vapor deposition apparatus, a heater or an electrostatic chuck using a metal base material such as stainless steel or an aluminum alloy is conventionally used. Has been used.

[0003] However, such a metal heater has the following problems.
There were the following problems. First, because it is made of metal,
The thickness of the heater plate must be as thick as about 15 mm. This is because, in a thin metal plate, warpage, distortion, and the like are generated due to thermal expansion caused by heating, and the silicon wafer placed on the metal plate is damaged or tilted. However, when the thickness of the heater plate is increased, there is a problem that the weight of the heater increases and the heater becomes bulky.

In addition, by changing the voltage or the amount of current applied to the resistance heating element, the temperature of a surface to be heated (hereinafter, referred to as a heating surface) such as a silicon wafer is controlled. Because of the thickness, the temperature of the heater plate does not quickly follow changes in the voltage or the amount of current, and there is a problem that it is difficult to control the temperature.

In Japanese Patent Application Laid-Open No. Hei 4-324276, aluminum nitride, which is a non-oxide ceramic having high thermal conductivity and high strength, is used as a substrate. A hot plate has been proposed in which through holes are formed and nichrome wires are brazed as external terminals to these through holes.

In such a hot plate, since an aluminum nitride substrate having high mechanical strength even at high temperatures is used, the thickness of the aluminum nitride substrate can be reduced and the heat capacity can be reduced. In addition, the temperature of the aluminum nitride substrate can be made to quickly follow a change in the current amount.

Further, such a hot plate is disclosed in Japanese Patent Application Laid-Open No. 2000-114355 and Japanese Patent No. 278398.
No. 0, a cylindrical ceramic and a disc-shaped ceramic are bonded via a ceramic bonding layer,
Means have been taken to protect wiring such as external terminals from reactive gases and halogen gases used in the semiconductor manufacturing process.

[0008]

However, such a hot plate made of aluminum nitride cannot be said to have sufficient corrosion resistance. In addition to being corroded to the deep portion of the aluminum substrate, it cannot be used, and aluminum nitride particles fall off and adhere to an object to be processed such as a silicon wafer, causing particles to be generated. Further, Japanese Patent Application Laid-Open No. 2000-114355,
In the hot plate described in Japanese Patent Application Publication No. JP-A-Heisei, 8-283980, and Japanese Patent No. 2783980, in order to strongly join the cylindrical ceramic and the disc-shaped ceramic, a ceramic joining layer is required. And the like, or applying a solution containing a sintering aid to these surfaces to be joined is an essential requirement, and the disc-shaped ceramic is made of Y ₂ O ₃ was not contained or its content was very low, less than 5% by weight.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a ceramic which does not corrode deeply and has excellent corrosion resistance even when continuously exposed to a reactive gas or a halogen gas for a long period of time. An object of the present invention is to realize a method for manufacturing a substrate and a bonded body that can directly and firmly bond a ceramic substrate and another ceramic body and have excellent corrosion resistance of the ceramic substrate.

[0010]

According to the present invention, there is provided a ceramic substrate provided with a conductor on the surface or inside thereof, wherein the ceramic substrate is made of Y ₂ O _3. It is.

The ceramic substrate of the present invention is made of Y ₂ O ₃ , has excellent corrosion resistance on its surface, and can be used for a long period of time even when exposed to a reactive gas or a halogen gas. The substrate is not corroded to a deep portion, and the Y ₂ O ₃ particles do not drop off from the ceramic substrate and adhere to an object to be processed such as a silicon wafer to generate particles. Note that the phrase “the ceramic substrate of the present invention is made of Y ₂ O ₃ ” does not mean that the ceramic substrate of the present invention is made of purely Y ₂ O _3, but that the ceramic substrate is made of Y ₂ O _3. This means that the main component of the composition is Y ₂ O ₃ , and in addition, for example, aluminum nitride or the like may be included.

It is preferable that another ceramic body is joined to the bottom surface of the ceramic substrate. When the ceramic substrate to which the other ceramic body is bonded is applied to a semiconductor manufacturing / inspection device, it is possible to prevent the ceramic substrate from warping and to protect external terminals and wiring from corrosive gas. can do.

The conductor is a resistance heating element,
The ceramic substrate desirably functions as a hot plate. This is because such a ceramic substrate is particularly desirably used at a high temperature. The resistance heating element may be formed in a layered form, or may be formed in a striated body.

Preferably, the conductor is an electrostatic electrode, and the ceramic substrate functions as an electrostatic chuck. This is because an electrostatic chuck is often used in a corrosive atmosphere, and a ceramic substrate is required to have high corrosion resistance.

[0015] The method of manufacturing a joined body of the present invention is a method of manufacturing a joined body in which another ceramic body is joined to the bottom surface of a ceramic substrate having a conductor provided therein.
The other ceramic body and the ceramic substrate are heated while the other ceramic body and the ceramic substrate made of Y ₂ O ₃ are in contact with each other.

According to the method for manufacturing a bonded body of the present invention, the above-mentioned ceramic substrate can be directly bonded to another ceramic body, and a bonded body having a ceramic substrate excellent in corrosion resistance can be manufactured. . That is, there is no need to join the ceramic substrate and another ceramic body via the ceramic joining layer or apply a solution containing a sintering aid to the surfaces to be joined.

Further, when the other ceramic body and the ceramic substrate are joined, they may be placed at 1500 to 20 mm.
It is desirable to heat to 00 ° C. This is because a joined body having excellent joining strength between the other ceramic body and the ceramic substrate can be manufactured.

Further, the conductor is a resistance heating element,
The ceramic substrate desirably functions as a hot plate. This is because a structure in which the ceramic substrate and the other ceramic body are joined as described above is particularly desirable when used at a high temperature. The resistance heating element may be formed in a layered form, or may be formed in a striated body.

Preferably, the conductor is an electrostatic electrode, and the ceramic substrate functions as an electrostatic chuck. This is because the electrostatic chuck is often used in a corrosive atmosphere, and the structure in which the ceramic substrate and the other ceramic body are joined as described above is optimal.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments. Note that the present invention is not limited to this description.

First, the ceramic substrate of the present invention will be described. The ceramic substrate of the present invention is a ceramic substrate provided with a conductor on its surface or inside, wherein the ceramic substrate is made of Y ₂ O ₃ .

The ceramic substrate of the present invention has a Y₂O₃From
And corrosive gas CF ₄Exposed to gas, etc.
Is not easily corroded to the depth
It has excellent corrosion resistance. This is the above ceramic
Substrate is the above CF₄When exposed to gas, on its surface,
The above CF₄Gas and Y react to make it dense with excellent corrosion resistance
YF₃Is generated. This YF₃Is the above ceramic base
By being formed into a film on the surface of the board,
It is considered that the corrosion resistance of the plate is improved.

The ceramic substrate of the present invention preferably contains about 1 to 50% by weight of aluminum nitride as a sintering aid. Aluminum nitride content is 1
If the amount is less than the weight percentage, when manufacturing the ceramic substrate, sintering of Y ₂ O ₃ becomes insufficient, and the strength of the ceramic substrate may be deteriorated. On the other hand, when the content of aluminum nitride exceeds 50% by weight, the corrosion resistance of the ceramic substrate is reduced, and when another ceramic body is provided on the bottom surface, the bonding strength with the other ceramic body is poor. May be sufficient. The reason why the bonding strength becomes insufficient will be described in detail in the method for manufacturing a bonded body according to the present invention described later.

The shape of the ceramic substrate of the present invention is preferably a disk shape, and the diameter is preferably 200 mm or more, and most preferably 250 mm or more. This is because the temperature of the disc-shaped ceramic substrate is required to be uniform, but the larger the diameter of the substrate, the more likely the temperature is to be non-uniform.

The thickness of the ceramic substrate of the present invention is 50 m
m or less, more preferably 20 mm or less. Further, 1 to 5 mm is optimal. If the thickness is too thin,
This is because, when heating at a high temperature, warpage tends to occur, while when it is too thick, the heat capacity becomes too large and the temperature rise / fall characteristics deteriorate.

The porosity of the ceramic substrate of the present invention is preferably 0 or 5% or less. The porosity is measured by the Archimedes method. This is because a decrease in the thermal conductivity at a high temperature and the occurrence of warpage can be suppressed.

Further, a conductor is provided on the surface or inside of the ceramic substrate of the present invention. When a conductor is provided on the surface, the CF
It is desirable to be coated with glass, resin, or the like that is durable to the _four gases. This is to prevent the conductor from being corroded to a deep portion by being exposed to the CF ₄ gas and to prevent the conductor from being oxidized by being exposed to air.

The glass which is durable to the CF ₄ gas is not particularly limited, and examples thereof include glass containing no silica (SiO ₂ ). Examples of the resin include polyimide, fluorine resin, and the like. BT resin and the like can be mentioned. When the conductor is provided inside the ceramic substrate, it is not necessary to cover with the glass, the resin, or the like.

Further, glass, resin or the like which is durable to the CF ₄ gas may be formed on the entire surface of the ceramic substrate on which the conductor is provided, so as to cover only the conductor. It may be formed. In either case, the conductor can be protected without being exposed to corrosive gas and air.

The brightness of the ceramic substrate of the present invention is JIS.
It is desirable that the value based on the definition of Z 8721 be N6 or less. This is because a material having such brightness is excellent in radiant heat and concealing property. In addition, for example, a hot plate made of such a ceramic substrate enables accurate surface temperature measurement by a thermoviewer.

Here, the lightness N is 0 for the ideal black lightness, 10 for the ideal white lightness, and the brightness of the color between these black lightness and white lightness. Each color is divided into ten so that the perception of the color is equal, and displayed by symbols N0 to N10. And the actual measurement is N0-N
The comparison is made with the color chart corresponding to No. 10. In this case, the first decimal place is 0 or 5.

A ceramic substrate having such characteristics can be obtained by including 100 to 5000 ppm of carbon in the substrate. There are two types of carbon, amorphous and crystalline.Amorphous carbon can suppress a decrease in volume resistivity at a high temperature of the substrate. Since a decrease in thermal conductivity 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, O
Hydrocarbons, preferably saccharides, can be obtained by calcining in air, and graphite powder can be used as the crystalline carbon.
In addition, carbon can be obtained by thermally decomposing the acrylic resin under an inert atmosphere and then heating and pressurizing. However, by changing the acid value of the acrylic resin, it is possible to obtain a crystalline (non-crystalline) material. Can be adjusted.

Further, the ceramic substrate of the present invention may have another ceramic body joined to the bottom surface. When the above ceramic substrate is applied to semiconductor manufacturing and inspection equipment,
It is possible to prevent the ceramic substrate from warping, and to prevent the wiring from the conductor from being corroded by the CF ₄ gas or the like, as described later. In particular, when a conductor is provided therein, there is no need to provide a bonding layer or apply a solution containing a sintering aid between the ceramic substrate and another ceramic body as in the related art. The ceramic substrate and the other ceramic body can be directly joined. The reason for this will be described in detail in the method for manufacturing a joined body of the present invention described later.

When a ceramic substrate having a bottom surface joined with another ceramic body is applied to a semiconductor manufacturing / inspection apparatus, the ceramic substrate is fixed to an upper portion of a supporting container having a bottom plate. Preferably, a cylindrical body is used as the ceramic body, and wiring from the conductor is stored in the cylindrical body joined to the bottom surface of the ceramic substrate. This is to prevent the wiring from being corroded by being exposed to corrosive gas or the like.

The other ceramic body is not particularly limited, and a ceramic body made of a nitride ceramic, a carbide ceramic, or the like can be used. Examples of the nitride ceramic include metal nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, and titanium nitride. Examples of the carbide ceramic include metal carbide ceramics such as silicon carbide, zirconium carbide, titanium carbide, tantalum carbide, and tansten carbide. Usually, Y ₂ O ₃ is contained in the inside of the other ceramic body.

In the ceramic substrate of the present invention, when the conductor is a resistance heating element and a conductor circuit, the ceramic substrate functions as a hot plate. When the ceramic substrate of the present invention functions as a hot plate, the ceramic substrate has a resistance heating element formed on the surface or inside thereof.
A hot plate having a resistance heating element formed inside a ceramic substrate will be described first, and a hot plate having a resistance heating element formed on the surface of the ceramic substrate will be described later.

FIG. 1 is a plan view schematically showing a hot plate which is an example of a ceramic substrate of the present invention and in which a resistance heating element is formed, and FIG. 2 is a sectional view thereof. 3 is a partially enlarged cross-sectional view of the vicinity of a cylindrical body made of aluminum nitride, which is another ceramic body shown in FIG.

As shown in FIG. 2, this hot plate 1
In the case of 0, the cylindrical body 17 is directly joined near the center of the bottom surface 11b of the disc-shaped ceramic substrate 11. Moreover, since the cylindrical body 17 is formed so as to be in close contact with the bottom plate (not shown) of the support container, the inside and the outside of the cylindrical body 17 are completely isolated.

Here, the bottom surface 11b of the ceramic substrate 11
That the cylindrical body 17 is directly joined to the vicinity of the center means that the bottom surface 11b of the ceramic substrate 11 and the cylindrical body 17 are joined without any intervention. That is, they are not joined through the ceramic joining layer as described above, nor are they joined by applying a solution containing a sintering aid to these joining surfaces.

As shown in FIG. 1, inside the ceramic substrate 11, resistance heating elements 12a to 12d, which are arc patterns repeatedly formed so as to draw a part of a concentric circle, are formed on the outer peripheral portion of the ceramic substrate 11. A resistive heating element 12e which is arranged and has a partially cut concentric pattern inside.
~ 12g are arranged.

Further, as shown in FIG.
A conductor circuit 18 extending toward the center of the ceramic substrate 11 is formed between the bottom surface 11b and the bottom surface 11b. The end 120 of the resistance heating element and one end of the conductor circuit 18 are connected via a via hole 130. ing.

The conductor circuit 18 is connected to the end 12 of the resistance heating element.
In the ceramic substrate 11, a through hole 13 'is formed immediately below the other end of the conductor circuit 18 extending to the vicinity of the inside of the cylindrical body 17. In addition, a blind hole 19 exposing the through hole 13 'is formed, and the through hole 13' is connected to a T-shaped external terminal 23 via a solder layer (not shown).

If the end 120 of the resistance heating element is inside the cylindrical body 17, no via hole or conductor circuit is required, so that the through hole 13 is formed directly at the end of the resistance heating element and the solder layer is formed. Is connected to the external terminal 23 via the.

A socket 25 having a conductive wire 230 is attached to these external terminals 23. The conductive wire 230 is drawn out through a through hole formed in a bottom plate (not shown), and is connected to a power source or the like. (Not shown).

On the other hand, a temperature measuring element 180 such as a thermocouple having a lead wire 290 is inserted into the bottomed hole 14 formed in the bottom surface 11b of the ceramic substrate 11 and made of a heat-resistant resin, ceramic (silica gel or the like) or the like. And sealed. The lead wire 290 passes through the inside of the insulator (not shown), and is drawn out through a through hole (not shown) formed in the bottom plate of the support container. The inside of the insulator is also isolated from the outside. Have been. Further, a through hole 15 for inserting a lifter pin (not shown) is provided in a portion near the center of the ceramic substrate 11.

The lifter pins are adapted to place an object to be processed such as a silicon wafer thereon and move it up and down, thereby transferring the silicon wafer to a carrier (not shown), And heating the silicon wafer placed on the heating surface 11a of the ceramic substrate 11 or supporting the silicon wafer at a distance of 50 to 2000 μm from the heating surface 11a to heat the silicon wafer. I can do it.

Also, a through hole or a concave portion is provided in the ceramic substrate 11, and a pin having a spire or a hemispherical tip is inserted into the through hole or the concave portion, and then the support pin is slightly protruded from the ceramic substrate 11. And the silicon wafer is supported by the support pins, so that the heating surface 1
Heating may be performed in a state of being separated from 1a by 50 to 2000 μm.

The bottom plate of the support vessel may be provided with a refrigerant introduction pipe or the like. In this case, the temperature, the cooling rate, and the like of the ceramic substrate 11 can be controlled by introducing the refrigerant into the refrigerant introduction pipe via the pipe.

As described above, this hot plate 10
In this case, the cylindrical body 17 is joined to the bottom surface 11b of the ceramic substrate 11, and the cylindrical body 17 is formed up to the bottom plate (container wall) of the support container (not shown). , Completely isolated.

Therefore, by protecting the conductive wire 230 drawn out from the through hole of the bottom plate with a tubular member, the periphery of the hot plate 10 becomes an atmosphere containing a corrosive gas such as CF ₄ gas. Even when the volatile gas or the like easily enters the inside of the support container, the wiring and the like inside the cylindrical body 17 do not corrode. Since the wiring 290 from the temperature measuring element 180 is also protected by an insulator or the like,
Does not corrode.

Further, an inert gas or the like is slowly flowed into the cylindrical body 17 so that corrosive gas such as CF ₄ gas does not flow into the cylindrical body 17.
Corrosion of the conductive wire 230 can be more reliably prevented.

The ceramic substrate 11 is made of Y ₂ O _3, and preferably contains about 1 to 50% by weight of aluminum nitride. This is as described for the ceramic substrate of the present invention. Further, the diameter, thickness and porosity of the ceramic substrate 11 are also desirably within the ranges described for the ceramic substrate of the present invention.

Since the cylindrical body 17 also has a function of firmly supporting the ceramic substrate 11, even when the ceramic substrate 11 is heated to a high temperature, it can be prevented from warping due to its own weight. As a result, the object to be processed such as a silicon wafer can be prevented from being damaged, and the object to be processed can be heated to a uniform temperature.

The cylindrical body 17 is made of aluminum nitride, but may contain Y ₂ O ₃ therein. The Y ₂ O ₃ functions as a sintering aid, and the cylindrical body 1
This is because the strength of No. 7 becomes excellent.

The amount of Y ₂ O ₃ contained in the cylindrical body 17 is not particularly limited, and may be the amount added when producing an aluminum nitride sintered body by a conventionally known method. Since the cylindrical body 17 is less exposed to corrosive gas such as CF ₄ gas than the ceramic substrate 11, the CF ₄
This is because corrosion is not so much caused by corrosive gas such as gas. Further, the amount of Y ₂ O ₃ contained in the cylindrical body 17 may be larger than that of the aluminum nitride sintered body manufactured by a conventionally known method. In this case, the corrosion resistance of the cylindrical body 17 is improved, and the cylindrical body 17 is hardly corroded by the corrosive gas such as the CF ₄ gas.

As shown in FIG. 1, the resistance heating element 12 has resistance heating elements 12a to 12d, which are formed in an arc pattern repeatedly formed so as to draw a part of a concentric circle, on the outer peripheral portion of the ceramic substrate 11. Inside thereof, resistance heating elements 12e to 12g each having a concentric pattern partially cut are arranged.

The outermost resistance heating element 12a is formed by repeatedly forming an arc-shaped pattern obtained by dividing a concentric circle into four parts in the circumferential direction, and ends of adjacent arcs are connected by bending lines to form a series of circuits. ing. Then, four circuits of the resistance heating elements 12a to 12d having the same pattern are formed close to each other so as to surround the outer periphery, and constitute an overall annular pattern.

The ends of the resistance heating elements 12a to 12d are formed inside an annular pattern in order to prevent the occurrence of a cooling spot or the like. Heading to

Resistance heating elements 12a-1 formed on the outermost periphery
Inside the 2d, there are formed resistance heating elements 12e to 12g each formed of a circuit of a concentric pattern whose part is cut off. In the resistance heating elements 12e to 12g, a series of circuits is formed by connecting the ends of adjacent concentric circles sequentially with a resistance heating element formed of a straight line.

The resistance heating elements 12a to 12d, 12
Between e, 12f, and 12g, a belt-shaped (annular) non-heating element non-forming area is provided, and a circular heating element non-forming area is also provided at the center.

Accordingly, as a whole, annular resistance heating element forming areas and heating element non-forming areas are alternately formed from the outside to the inside, and these areas are defined by the size (diameter) of the ceramic substrate. ), Thickness, etc., the temperature can be made uniform by setting the temperature appropriately.

FIG. 4 is a plan view schematically showing another example of the hot plate according to the present invention. In this hot plate 40, the resistance heating elements 42 are arranged on the outermost periphery of the ceramic substrate 41, with resistance heating elements 42 a to 42 d having a repeating pattern of bent lines, and inside the resistance heating elements 42 e to 42 e having a concentric pattern. 42h are arranged.

It is desirable that the number of circuits of the resistance heating elements formed on the hot plate according to the present invention be two or more. For example, in order to make the temperature of the heating surface of the hot plate more uniform, 200-30 diameter
When it is 0 mm, the total number of circuits is preferably 2 to 7. When the diameter of the ceramic substrate exceeds 300 mm, the total number of circuits is preferably 7 to 8.

The pattern of the resistance heating element is not particularly limited. For example, the pattern shown in FIG. 1 is a combination of a circular arc repetition pattern and a concentric pattern, and the pattern shown in FIG. Examples include a pattern that is used in combination with a concentric pattern, a spiral pattern, an eccentric pattern, and a repeated pattern of bent lines. These can be used in combination. Among these, it is desirable to use a repeating pattern of arcs, a concentric pattern, and a repeating pattern of bending lines.

Further, with regard to the pattern arrangement, finer control of the calorific value can be performed on the outer peripheral portion of the ceramic substrate which has a large heat radiation. On the outer circumference,
A pattern in which a resistance heating element composed of at least two or more circuits is arranged in the circumferential direction, and a resistance heating element composed of another circuit is arranged inside the resistance heating element disposed on the outermost periphery. .

The pattern divided in the circumferential direction means that a plurality of line segments are drawn from the center of the ceramic substrate to the outer periphery.
This is a pattern formed in a region divided by the line segment. Usually, it is desirable that all the areas have the same size.

1 and 4, the resistance heating element 1
2a to 12d and 42a to 42d are resistance heating elements arranged at the outermost periphery, and such resistance heating elements at the outermost periphery are:
It is desirable that the area be formed in a region 90% or more from the center to the distance from the outer periphery to the center. If it is less than 90%, the area of the resistance heating element formed on the outermost periphery becomes too large, so that it becomes difficult to control the temperature of the heating surface.

Further, it is desirable that the number of circuits of the resistance heating element formed on the outermost periphery and the number of circuits of the resistance heating element formed therein are approximately equal. If the number of circuits on the outermost periphery is extremely large, the number of circuits in the inside will be small, and it will be difficult to accurately control the amount of heat generation inside the ceramic substrate. This is because accurate temperature control cannot be performed.

In the hot plate according to the present invention, the thickness of the resistance heating element is desirably 1 to 50 μm, and the width thereof is desirably 5 to 20 μm. The resistance value can be changed by changing the thickness or width of the resistance heating element, but this range is the most practical. The resistance value of the resistance heating element increases as its thickness decreases and its width decreases.

The resistance heating element may have any of a square, an elliptical, a spindle-shaped, and a semi-cylindrical-shaped cross section, but is preferably flat. This is because the flat shape facilitates heat radiation toward the heating surface, so that the amount of heat propagation to the heating surface 11a can be increased, and the temperature distribution on the heating surface 11a is hardly formed.
The resistance heating element may have a spiral shape.

When the resistance heating element is formed inside the ceramic substrate, its formation position is not particularly limited, but 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. preferable. This is because heat is diffused while propagating to the heating surface, and the temperature on the heating surface tends to be uniform.

When forming the resistance heating element inside the ceramic substrate, it is preferable to use a conductive paste made of metal or conductive ceramic. That is, when forming a resistance heating element inside a ceramic substrate, a conductive paste layer is formed on a green sheet, and then the green sheet is laminated and fired to produce the resistance heating element inside.

The conductive paste is not particularly limited, but preferably contains not only metal particles or conductive ceramics for ensuring conductivity, but also resin, solvent, 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 hard to oxidize and have a resistance value sufficient to generate heat.

As the conductive ceramic, for example,
Tungsten, molybdenum carbide and the like can be mentioned.
These may be used alone or in combination of two or more. The metal particles or conductive ceramic particles preferably have a particle size of 0.1 to 100 μm. If it is too fine, less than 0.1 μm, it is liable to be oxidized, while if it exceeds 100 μm, sintering becomes difficult and the resistance value becomes large.

Even if the shape of the metal particles is spherical,
It may be scaly. When these metal particles are used, they may be a mixture of the above-mentioned spheres and the above-mentioned flakes. When the metal particles are scaly or a mixture of spherical and scaly, the metal oxide between the metal particles is easily retained, and the adhesion between the resistance heating element and the ceramic substrate is ensured. And the resistance value can be increased.

As the resin used for the conductor paste,
For example, an epoxy resin, a phenol resin, and the like can be given. Examples of the solvent include isopropyl alcohol. Examples of the thickener include cellulose and the like.

As shown in FIG. 2, when the conductor circuit 18 is formed inside the ceramic substrate 11, the conductor made of the metal or conductive ceramic used for forming the above-described resistance heating element 12 is used. A paste can be used, and a conductor paste or the like usually used when forming an electrode or the like can be used.

The size of the conductor circuit 18 is not particularly limited.
The width is preferably 0.1 to 50 mm, the thickness is preferably 0.1 to 500 μm, and the length is the distance from the end of the resistance heating element 12 to the inside of the cylindrical body 17 joined near the center of the ceramic substrate 11. It is adjusted appropriately according to.

The hot plate according to the present invention has a temperature of 100 ° C.
It is preferable to use at 200 ° C. or more.

In the present invention, the conductive line 230 connected to the external terminal 23 via the socket 25 is
In order to prevent a short circuit or the like between them, it is desirable that they be covered with a heat-resistant insulating member. Examples of such an insulating member include aluminum nitride similar to that of the cylindrical body 17, oxide ceramics such as alumina, silica, mullite, and cordierite, silicon nitride, and silicon carbide.

In the hot plates shown in FIGS. 1 to 3 and 4, a ceramic substrate is usually fitted on an upper portion of a supporting container (not shown). However, in other embodiments, the substrate is It may be placed on the upper surface of a support container having a substrate receiving portion at the upper end and fixed by a fixing member such as a bolt.

In the present invention, a thermocouple can be used as the temperature measuring element 180 as shown in FIG. This is because the temperature of the resistance heating element can be measured using a thermocouple, and the temperature and the amount of current can be changed based on the data to control the temperature.

The size of the junction of the thermocouple lead wires is preferably equal to or larger than the element diameter of each lead wire and 0.5 mm or less. With such a configuration, the heat capacity of the junction is reduced, and the temperature is accurately and quickly converted to a current value. For this reason, the temperature controllability is improved, and the temperature distribution on the heating surface 11a of the wafer is reduced. Examples of the thermocouple include K-type, R-type, B-type, E-type, J-type, and T-type thermocouples as described in JIS-C-1602 (1980).

In addition to the above-mentioned thermocouples, the hot plate temperature measuring means according to the present invention includes, for example, a platinum temperature measuring resistor,
In addition to a temperature measuring element such as a thermistor, a temperature measuring means using an optical means such as a thermoviewer may also be used.

When the above-mentioned thermoviewer is used, the temperature of the heated surface of the ceramic substrate can be measured, and the temperature of the surface of the object to be heated such as a silicon wafer can be directly measured. The accuracy of temperature control is improved.

The ceramic substrate of the present invention is used for manufacturing a semiconductor or inspecting a semiconductor, and specifically includes, for example, an electrostatic chuck, a susceptor, a hot plate (ceramic heater) and the like. .

The above-mentioned hot plate is a device in which only a resistance heating element is provided inside a ceramic substrate, and thereby, an object to be processed such as a silicon wafer is placed on or separated from the surface of the ceramic substrate and held. It can be heated to a predetermined temperature or cleaned.

When the hot plate according to the present invention has a resistance heating element formed on the surface of a ceramic substrate, at least the resistance heating element is formed as described for the ceramic substrate according to the invention. It is desirable that a coating layer made of glass, resin, or the like that is resistant to CF ₄ gas be formed in the region. This can prevent corrosion caused by the resistance heating element being directly exposed to CF ₄ gas, and can prevent oxidation of the resistance heating element by air. In addition,
In this case, since the external terminals and the like are directly exposed to the CF ₄ gas, it is desirable that the external terminals and the like be covered with a resin or the like having excellent corrosion resistance.

In the ceramic substrate of the present invention, when the conductor is an electrostatic electrode and a conductor circuit, the ceramic substrate functions as an electrostatic chuck. FIG.
FIG. 6 is a vertical cross-sectional view schematically showing such an electrostatic chuck, FIG. 6 is a partially enlarged cross-sectional view thereof, and FIG. 7 is a vicinity of an electrostatic electrode formed on a substrate constituting the electrostatic chuck. It is a horizontal sectional view which shows typically.

Inside the ceramic substrate 31 constituting the electrostatic chuck 30, semi-circular chuck positive / negative electrostatic layers 32a and 32b are disposed to face each other, and a ceramic dielectric film is formed on these electrostatic electrodes. 34 are formed. Further, inside the ceramic substrate 31, a resistance heating element 320 is provided.
Is provided so that an object to be processed such as a silicon wafer can be heated. The ceramic substrate 3
1, an RF electrode may be embedded as needed.

The above-mentioned electrostatic electrode is made of a noble metal (gold, silver, platinum,
It is preferably made of a metal such as palladium), lead, tungsten, molybdenum, nickel, or a conductive ceramic such as a carbide of tungsten or molybdenum. These may be used alone or in combination of two or more.

As shown in FIG. 5 and FIG. 6, this electrostatic chuck 30
2b, a through hole 33 is formed immediately below the end of each of the electrostatic electrodes 32a and 32b, and a ceramic dielectric film 34 is formed on the electrostatic electrode 32. Is configured.

That is, the cylindrical body 37 is joined near the center of the bottom surface of the ceramic substrate 31, and through holes 33, 330 are formed above the inside of the cylindrical body 37, and these through holes 33 are formed. , 330 are the electrostatic electrodes 3
2a, 32b and the resistance heating element 320, as well as being connected to an external terminal 360 inserted into the blind hole 390. One end of the external terminal 360 is connected to a socket 350 having a conductive wire 331. The conductive wire 331 is drawn out from a through hole (not shown).

In the case of the resistance heating element 320 having an end outside the cylindrical body 37, similarly to the case of the hot plate 10 shown in FIGS. By forming the hole 330 ', the end of the resistance heating element 320 extends inside the cylindrical body 37 (see FIG. 6). Therefore, the through hole 330 '
The external terminal 360 is inserted into and connected to the blind hole 390 that exposes the external terminal 360.
Can be stored.

When operating such an electrostatic chuck 30, a voltage is applied to each of the resistance heating element 320 and the electrostatic electrode 32. Thereby, the electrostatic chuck 30
The silicon wafer placed thereon is heated to a predetermined temperature and is electrostatically attracted to the ceramic substrate 31. Note that the electrostatic chuck does not necessarily need to include the resistance heating element 320.

FIG. 8 is a horizontal sectional view schematically showing electrostatic electrodes formed on a substrate of another electrostatic chuck. Inside the substrate 71, a chuck positive electrode electrostatic layer 72 including a semicircular portion 72a and a comb tooth portion 72b, and a semicircular portion 73a
And a chuck negative electrostatic layer 73 composed of a comb tooth portion 73b are arranged to face each other so as to cross the comb tooth portions 72b, 73b.

FIG. 9 is a horizontal sectional view schematically showing an electrostatic electrode formed on a substrate of still another electrostatic chuck. In this electrostatic chuck, four circles are formed inside the substrate 81.
Chuck positive electrode electrostatic layers 82a and 82b and chuck negative electrode electrostatic layers 83a and 83b having divided shapes are formed. Further, the two chuck positive electrode electrostatic layers 82a, 82b and 2
The chuck negative electrode electrostatic layers 83a and 83b are formed so as to cross each other. In the case of forming an electrode in which a circular electrode or the like is divided, the number of divisions is not particularly limited, and may be five or more, and the shape is not limited to a sector.

Next, a method for manufacturing the joined body of the present invention will be described. Method for producing a joined body of the present invention, the bottom surface of the ceramic substrate inside the conductor is provided, a manufacturing method of the bonded body to bond the other ceramic body, and the other ceramic body, Y ₂ The other ceramic body and the ceramic substrate are heated while the ceramic substrate made of O ₃ is in contact with the ceramic substrate.

According to the method for producing a joined body of the present invention, it is necessary to join via a ceramic joining layer or to apply a solution containing a sintering aid to the surfaces to be joined, as in the prior art. Instead, the ceramic substrate can be directly joined to another ceramic body. This is considered to be due to the following reasons.

In the method for manufacturing a joined body of the present invention, the ceramic substrate is made of Y ₂ O ₃ similarly to the above-described ceramic substrate of the present invention, and a certain amount of aluminum nitride is contained therein. Have been. On the other hand, as the above-mentioned other ceramic body, the same ceramic body as the above-mentioned other ceramic body in the ceramic substrate of the present invention can be used. The method for manufacturing a joined body according to the present invention includes heating such a ceramic substrate and another ceramic body to approximately the sintering temperature of aluminum nitride in a state where the ceramic substrate is in contact with the other ceramic bodies. Y ₂ O ₃ diffuses into the other ceramic body, and the aluminum nitride particles present at the interface between the ceramic substrate and the other ceramic body join and grow according to the diffusion of the Y ₂ O _3. . It is considered that the aluminum nitride particles grown at the interface between the ceramic substrate and the other ceramic body firmly join the ceramic substrate and the other ceramic body.

The diffusion of Y ₂ O ₃ depends on the relationship between the distance from the surface of the ceramic substrate and the Y ₂ O ₃ content before the ceramic substrate and the other ceramic body are joined, and After the ceramic substrate and the other ceramic body are joined, the relationship between the distance from the surface of the ceramic substrate and the content of Y ₂ O ₃ is examined, and the two can be easily confirmed by comparing the two. it can.

Hereinafter, a method of manufacturing a hot plate will be described as an example of a method of manufacturing a joined body of the present invention with reference to FIG. In addition, as another ceramic body,
A case where a cylindrical body is used will be described. FIG.
0 (a) to (d) are cross-sectional views schematically showing a part of a method for manufacturing a hot plate having a resistance heating element inside a substrate made of Y ₂ O ₃ .

(1) Green Sheet Production Step First, a paste is prepared by mixing yttrium oxide powder with a binder, a solvent, and the like, and a green sheet is produced using the paste.

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

The paste obtained by mixing these is formed into a sheet by a doctor blade method to form a green sheet 5.
0 is produced. The thickness of the green sheet 50 is 0.1 to
5 mm is preferred. Next, a green sheet formed with a portion 630 serving as a via hole for connecting the end portion of the resistance heating element and the conductor circuit, and portions 63 serving as through holes for connecting the conductor circuit and the external terminals. 'To form a green sheet.

If necessary, a portion serving as a through hole for inserting a lifter pin for carrying a silicon wafer, a portion serving as a through hole for inserting a support pin for supporting a silicon wafer, a thermocouple, or the like may be used. A portion serving as a bottomed hole for embedding the temperature measuring element is formed. The above-described processing may be performed on the through holes and the bottomed holes after forming a green sheet laminate described later, or after forming and firing the laminate.

The portions 630 serving as via holes and the portions 63 and 63 'serving as through holes may be filled with the above-mentioned paste to which carbon has been added. This is because carbon in the green sheet reacts with tungsten or molybdenum filled in the through holes to form carbides thereof.

(2) Step of Printing Conductive Paste on Green Sheet A conductive paste containing a metal paste or a conductive ceramic is printed on the green sheet on which a portion 630 to be a via hole is formed to form a conductive paste layer 62. I do.
These conductive pastes contain metal particles or conductive ceramic particles.

The average particle diameter of the metal particles such as tungsten particles or molybdenum particles is preferably 0.1 to 5 μm. If the average particle size is less than 0.1 μm or more than 5 μm, it is difficult to print the conductive paste.

Examples of the conductive paste include 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. 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.

Further, portions 63 and 6 to be through holes
On the green sheet on which the 3 'is formed, a conductive paste that is generally used when forming an electrostatic electrode or the like is printed to form a conductive paste layer 68.

(3) Green Sheet Laminating Step On the green sheet on which the conductor paste layer 62 has been printed, a plurality of green sheets 50 on which the conductor paste has not been printed are laminated, and under the green sheet, a conductor paste layer 68 is formed. Stack the sheets. Then, under the green sheet, a plurality of green sheets 50 on which nothing is printed are further laminated (FIG. 10A).

At this time, the number of the green sheets 50 laminated on the upper side of the green sheet on which the conductive paste layer 62 is printed is larger than the number of the green sheets 50 laminated on the lower side, and the formation position of the resistance heating element to be manufactured is formed. Is eccentric toward the bottom side. Specifically, the number of stacked green sheets 50 on the upper side is preferably 20 to 50, and the number of stacked green sheets 50 on the lower side is preferably 5 to 20.

(4) Green Sheet Laminate Firing Step The green sheet laminate is heated and pressurized to sinter the green sheet 50 and the internal conductor paste layers 62, 68, etc. 12 and the conductor circuit 18 are manufactured (FIG. 10B). The heating temperature is preferably from 1000 to 2000 ° C.,
10-20 MPa is preferable. Heating is performed in an inert gas atmosphere. As the inert gas, for example, argon,
Nitrogen or the like can be used.

Next, the bottom surface 11b of the ceramic substrate 11
Is provided with a bottomed hole for inserting a temperature measuring element (not shown). The bottomed hole can be formed by performing blast processing such as drilling or sand blasting after surface polishing. The above-described bottomed hole or concave portion may be provided after a ceramic substrate 11 described later and the cylindrical body 17 are joined, and a portion serving as a bottomed hole is provided in the green sheet 50 in advance, and the green sheet 50 is provided. It may be formed simultaneously with lamination and firing. Also, the internal resistance heating element 12
A blind hole 19 is formed in order to expose through holes 13 and 13 'for connection with the holes. The blind hole 19 may also be provided after the ceramic substrate 11 and the cylindrical body 17 are joined.

(5) Production of Cylindrical Body Aluminum nitride powder is put into a cylindrical mold, molded and cut as required. This is heated to 1000-2
The cylindrical body 17 is manufactured by sintering at 000 ° C. and normal pressure. The sintering is performed in an inert gas atmosphere. As the inert gas, for example, argon, nitrogen, or the like can be used. Here, the aluminum nitride powder contains 0.1 to
It is desirable to contain 30% by weight of Y ₂ O ₃ .
This is because the aluminum nitride substrate and the cylindrical body can be preferably directly joined. The size of the cylindrical body 17 is adjusted so that the through holes 13 and 13 ′ formed inside the ceramic substrate 11 fit inside. Next, the end surface of the cylindrical body 17 is polished and flattened.

(6) Joining of Ceramic Substrate and Cylindrical Body Near the center of the bottom surface 11b of the ceramic substrate 11 and the cylindrical body 1
The ceramic substrate 11 and the cylindrical body 17 are heated while the end faces of the ceramic substrate 7 are in contact with each other, and they are joined. At this time, the cylindrical body 17 is joined to the bottom surface 11b of the ceramic substrate 11 so that the through holes 13 and 13 'in the ceramic substrate 11 fit inside the inner diameter of the cylindrical body 17 (FIG. 10).
(C)). The ceramic substrate 11 and the cylindrical body 17 are
It is desirable to heat to 00-2000 ° C. By diffusing Y ₂ O ₃ in the ceramic substrate 11 into the cylindrical body 17,
At the interface between the ceramic substrate 11 and the cylindrical body 17, aluminum nitride particles can be favorably grown,
This is because the ceramic substrate 11 and the cylindrical body 17 can be firmly joined.

(7) Attachment of Terminals, etc. The external terminals 23 are inserted into the bag holes 19 formed inside the inner diameter of the cylindrical body 17 via solder or brazing material, and are heated and reflowed. 23 through hole 13,
13 '(FIG. 10 (d)). The heating temperature is
In the case of soldering, the temperature is preferably from 90 to 450 ° C, and in the case of processing with a brazing material, the temperature is preferably from 900 to 1100 ° C.

Next, the external terminal 23 is connected to a conductive line 230 connected to a power supply via a socket 25 (FIG. 2).
reference). Furthermore, by inserting a thermocouple or the like as a temperature measuring element into the formed bottomed hole and sealing it with a heat-resistant resin or the like, a hot plate provided with a cylindrical body that is another ceramic body on the bottom surface thereof. Can be manufactured.

In this hot plate, a semiconductor wafer such as a silicon wafer is placed on the hot plate, or the silicon wafer or the like is held by lifter pins or support pins, and then heated or cooled. The operation such as washing can be performed while performing.

When manufacturing the hot plate, an electrostatic chuck can be manufactured by providing an electrostatic electrode inside the ceramic substrate. However, in this case,
It is necessary to form a through hole for connecting the electrostatic electrode and the external terminal, but it is not necessary to form a through hole for inserting the support pin.

When electrodes are provided inside the ceramic substrate, a conductive paste layer serving as an electrostatic electrode may be formed on the surface of the green sheet as in the case of forming a resistance heating element.

Hereinafter, the present invention will be described in more detail.

(Example 1) Manufacturing of an electrostatic chuck (FIG. 5)
(1) Y ₂ O ₃ (manufactured by Nippon Yttrium Co., Ltd .;
4 μm) 80 parts by weight, 20 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1 μm), 12 parts by weight of an acrylic resin binder, 0.5 part by weight of a dispersant and 1-
A green sheet having a thickness of 0.47 mm was obtained by molding using a composition obtained by mixing 53 parts by weight of alcohol consisting of butanol and ethanol by a doctor blade method.

(2) Next, the green sheet is heated to 80 ° C.
After drying for 5 hours, a green sheet that has not been subjected to any processing, a green sheet provided with through holes for via holes for connecting the resistance heating element and the conductor circuit by punching, a conductor circuit and an external A green sheet provided with a through hole for a via hole for connecting a terminal and a green sheet provided with a through hole for a through hole for connecting an electrostatic electrode and an external terminal were produced.

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

(4) Conductive paste A was printed by a screen printing method on the surface of the green sheet provided with the through holes for via holes, and a conductive paste layer serving as a resistance heating element was printed. Further, the conductive paste A was printed by a screen printing method on the surface of the green sheet provided with through holes for through holes for connecting the conductor circuit and the external terminals, and a conductor paste layer serving as a conductor circuit was printed. . Further, a conductive paste layer composed of an electrostatic electrode pattern having the shape shown in FIG. 6 was formed on a green sheet that had not been subjected to any processing.

Further, the conductive paste B was filled in the through hole for connecting the resistance heating element and the conductor circuit and the through hole for connecting the external terminal.

Next, the green sheets subjected to the above treatment were laminated. First, on the upper side (heating surface side) of the green sheet on which the conductive paste layer serving as the resistance heating element is printed, 34 green sheets having only the portion to be the through hole 33 are laminated, and immediately below (the bottom surface) Side), a green sheet on which a conductive paste layer to be a conductive circuit is printed is laminated, and further, through holes 33, 33 are formed below the green sheet.
Twelve green sheets in which portions of 0, 330 'were formed were laminated. On the top of the green sheet thus laminated, a green sheet on which a conductor paste layer composed of an electrostatic electrode pattern is printed is laminated, and two unprocessed green sheets are further laminated thereon. The laminate was formed by pressure bonding at 130 ° C. and a pressure of 8 MPa.

(5) Next, the obtained laminate was degreased in a nitrogen gas at 600 ° C. for 5 hours, and then hot-pressed at 1890 ° C. and a pressure of 15 MPa for 3 hours to obtain a thickness of 3 m.
m yttrium oxide plate was obtained. The plate-like body contained 20% by weight of aluminum nitride.
This is cut into a disk shape having a diameter of 230 mm, and a resistance heating element 320 having a thickness of 5 μm and a width of 2.4 mm, a conductor circuit 380 having a thickness of 20 μm and a width of 10 mm, and a chuck positive electrode having a thickness of 6 μm are provided therein. A ceramic substrate 31 having an electric layer 32a and a chuck negative electrode electrostatic layer 32b was used.

(6) Next, the ceramic substrate 31 obtained in (5) is polished with a diamond grindstone, a mask is placed thereon, and blast processing with glass beads is performed on the surface to form bottomed holes for thermocouples. 300 is provided, and a portion of the bottom surface 31b of the ceramic substrate 31 where the through holes 33 and 33 'are formed is cut out to form a blind hole 390.

(7) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Co., average particle size 1.1 μm), 4 parts by weight of Y ₂ O ₃ (manufactured by Nippon Yttrium Co., average particle size 0.4 μm),
Acrylic resin binder 11.5 parts by weight, dispersant 0.5
Using a composition in which 1 part by weight and 53 parts by weight of alcohol composed of 1-butanol and ethanol are mixed, granules are produced by a spray-drying method, and the granules are placed in a pipe-shaped mold and fired at 1890 ° C. under normal pressure at normal pressure. And the end face is polished, the surface roughness is set to Ra = 0.1 μm, the length is 200 mm,
An aluminum nitride cylindrical body having an outer diameter of 52 mm and an inner diameter of 39 mm was manufactured. In addition, this cylindrical body contained 4% by weight of Y ₂ O ₃ .

(8) Then, the end face of the cylindrical body 37 is brought into contact with the bottom surface 31b of the ceramic substrate 31 at a position where the blind hole 390 fits inside the inner diameter of the ceramic substrate 31.
C., the ceramic substrate 31 and the cylindrical body 37 are heated.
And joined.

(9) Next, the bag hole 39 inside the cylindrical body 37
0, silver brazing (Ag: 40% by weight, Cu: 30% by weight,
The external terminals 360 were attached using Zn: 28% by weight, Ni: 1.8% by weight, balance: other elements, reflow temperature: 800 ° C). Then, the conductive wire 331 was connected to the external terminal 360 via the socket 350.

(10) Then, a thermocouple for temperature control is inserted into the bottomed hole 300, filled with silica sol,
Curing and gelling at 2 ° C. for 2 hours, the other ceramic body is made of aluminum nitride on the bottom surface of the ceramic substrate in which the electrostatic electrodes, resistance heating elements, conductor circuits, via holes and through holes are provided. Were joined, and the joined body in which the ceramic substrate functioned as an electrostatic chuck was manufactured.

(Example 2) Production of hot plate (see FIGS. 1 to 3 and FIG. 9) (1) Y ₂ O ₃ (manufactured by Nippon Yttrium Co., Ltd .;
4 μm) 80 parts by weight, 20 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1 μm), 11.5 parts by weight of an acrylic resin binder, 0.5 part by weight of a dispersant, and 1-butanol and ethanol Alcohol 53
A green sheet having a thickness of 0.47 mm was produced by using a paste mixed with parts by weight by a doctor blade method.

(2) Next, the green sheet was heated to 80 ° C.
After drying for 5 hours, a portion serving as a through hole 15 for inserting a lifter pin for carrying a silicon wafer or the like as shown in FIG. 1, a portion 630 serving as a via hole,
In addition, portions 63 and 63 'to be through holes are formed by punching.

(3) 100 parts by weight of tungsten carbide particles having an average particle diameter of 1 μm, 3.0 parts by weight of an acrylic binder, 3.5 parts by weight of an α-terpineol solvent, and 0.3 part by weight of a dispersant were mixed to form a conductor. Paste A was prepared.

Tungsten particles 100 having an average particle size of 3 μm
A conductive paste B was prepared by mixing 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.

The conductive paste A was printed by screen printing on a green sheet on which a portion 630 to be a via hole was formed, to form a conductive paste layer 62 for a resistance heating element. The printing pattern was a concentric pattern as shown in FIG. 1, the width of the conductive paste layer 62 was 10 mm, and the thickness thereof was 12 μm.

Subsequently, the conductor paste A was printed by screen printing on the green sheet on which the portion 63 'to be a through hole was formed, to form a conductor paste layer 68 for a conductor circuit. The shape of the printing was band-shaped.

The conductive paste B is applied to the portions 630 to be via holes and the portions 63 and 6 to be through holes.
Filled 3 '.

On the green sheet on which the conductor paste layer 62 having been subjected to the above processing is printed, 37 green sheets on which the conductor paste has not been printed are superimposed, and the green sheet on which the conductor paste layer 68 has been printed is superimposed thereunder. After
Furthermore, 12 green sheets on which the conductor paste was not printed were further stacked under them, and were stacked at 130 ° C. and a pressure of 8 MPa.

(4) Next, the obtained laminate was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. under a pressure of 15M.
Hot pressing was performed at Pa for 10 hours to obtain a yttrium oxide plate having a thickness of 3 mm. The plate-like body contained 20% by weight of aluminum nitride. This is 230
Cut out into a circular disk with a thickness of 6 mm and a width of 10 m inside.
m, a conductor circuit 18 having a thickness of 20 μm and a width of 10 mm, a via hole 130 and a through hole 1
A ceramic substrate 11 having 3, 13 'was obtained.

(5) Next, the ceramic substrate 11 obtained in (4) is polished with a diamond grindstone, a mask is placed thereon, and blast processing with glass beads is performed on the surface to form bottomed holes for thermocouples. 14 was formed, and a blind hole 19 was formed by digging a portion of the bottom surface 11b of the ceramic substrate 11 where the through holes 13 and 13 'were formed.

(6) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Co., average particle size 1.1 μm), 4 parts by weight of Y ₂ O ₃ (manufactured by Nippon Yttrium Co., average particle size 0.4 μm),
Acrylic resin binder 11.5 parts by weight, dispersant 0.5
Using a composition in which 1 part by weight and 53 parts by weight of alcohol composed of 1-butanol and ethanol are mixed, granules are produced by a spray-drying method, and the granules are placed in a cylindrical mold and fired at 1890 ° C. at normal pressure and normal pressure. And polished the end face,
A cylindrical body 17 having a surface roughness of Ra = 0.1 μm, a length of 200 mm, an outer diameter of 52 mm and an inner diameter of 39 mm was manufactured. The cylindrical body 17 contained 4% by weight of Y ₂ O ₃ .

(7) Thereafter, the end face of the cylindrical body 17 is brought into contact with the bottom surface 11b of the ceramic substrate 11 at a position where the blind hole 19 fits inside the inside diameter thereof, and
, The ceramic substrate 11 and the cylindrical body 17 were joined.

(8) Next, the blind hole 19 inside the cylindrical body 17
In addition, silver brazing (Ag: 40% by weight, Cu: 30% by weight, Z
n: 28% by weight, Ni: 1.8% by weight, balance: other elements, reflow temperature: 800 ° C.)
3 was attached. Then, the socket 25 is connected to the external terminal 23.
The conductive line 230 was connected via the.

(9) A thermocouple for temperature control is inserted into the bottomed hole 14, filled with silica sol, cured at 190 ° C. for 2 hours and gelled, so that a resistance heating element and a conductor A cylindrical body made of aluminum nitride was bonded as another ceramic body to the bottom surface of the ceramic substrate provided with circuits, via holes and through holes, and a bonded body in which the ceramic substrate functioned as a hot plate was manufactured.

Example 3 Example 1 was repeated except that the amount of aluminum nitride contained in the ceramic substrate was 3% by weight.
In the same manner as in the above, a joined body was manufactured.

Example 4 A joined body was manufactured in the same manner as in Example 2 except that the amount of aluminum nitride contained in the ceramic substrate was 0.8% by weight.

Example 5 A joined body was manufactured in the same manner as in Example 1 except that the amount of aluminum nitride contained in the ceramic substrate was changed to 10% by weight.

Example 6 A joined body was manufactured in the same manner as in Example 2, except that the amount of aluminum nitride contained in the ceramic substrate was 30% by weight.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the main material of the ceramic substrate was aluminum nitride, and the amount of Y ₂ O ₃ contained in the aluminum nitride ceramic substrate was 4% by weight. However, an attempt was made to manufacture a joined body, but the ceramic substrate and the tubular body could not be joined.

The following evaluation tests were performed on the ceramic joined bodies according to Examples 1 to 6 and Comparative Example 1. In addition,
In Comparative Example 1, since the ceramic substrate and the cylindrical body could not be directly bonded, a solution containing a sintering aid was applied to the surface where the ceramic substrate and the cylindrical body were bonded, and sintering was performed. By doing so, a joined body was manufactured, and a ceramic joined body according to Comparative Example 1 was obtained.

(1) Evaluation of Corrosion Resistance A CF ₄ gas was sprayed on the substrate constituting each joined body, and it was confirmed whether or not the substrate was corroded to a deep portion. The results are shown in Table 1 below. In Table 1, those in which only the surface was corroded were denoted by ○, and those that were corroded to the deep portion were denoted by x.

(2) Measurement of Breaking Strength A bending strength test was performed to measure the breaking strength of the joint surface.

(3) Heat cycle test As a heat cycle test, each joint was maintained at 25 ° C., heated to 450 ° C., and then subjected to an underwater drop test in which it was dropped into water. As a result, in the ceramic joined bodies according to Examples 1 to 6 and Comparative Example 1, the ceramic substrate and the cylindrical body did not break.

[0160]

[Table 1]

As is clear from the results shown in Table 1, the ceramic substrates constituting the joined bodies according to Examples 1 to 6 were not corroded to a deep portion by CF ₄ gas. Further, the breaking strength of these joined bodies is 400 to 800.
MPa, and had sufficiently large bonding strength. On the other hand, the aluminum nitride substrate according to Comparative Example 1 and the cylindrical body cannot be bonded, and in order to bond the aluminum nitride substrate and the cylindrical body, a ceramic bonding layer is formed between them, Alternatively, it is necessary to apply a solution containing a sintering aid to these joint surfaces. Further, in the aluminum nitride substrate according to Comparative Example 1, a portion corroded to a deep portion by the CF ₄ gas was observed.

[0162]

As described above, the ceramic substrate of the present invention is made of Y ₂ O ₃ even if the ceramic substrate is continuously exposed to a corrosive gas such as CF ₄ gas. It is excellent in corrosion resistance without being easily corroded to a deep part.

Further, since the method for manufacturing a joined body of the present invention is as described above, the ceramic substrate made of Y ₂ O ₃ can be directly joined to another ceramic body, and it is excellent in corrosion resistance. A ceramic substrate can be manufactured.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a hot plate which is an example of a ceramic substrate of the present invention.

FIG. 2 is a cross-sectional view of the hot plate shown in FIG.

FIG. 3 is a partially enlarged sectional view schematically showing a ceramic substrate constituting the hot plate shown in FIG. 1;

FIG. 4 is a plan view schematically showing another example of a hot plate as an example of the ceramic substrate of the present invention.

FIG. 5 is a longitudinal sectional view schematically showing a ceramic substrate constituting an electrostatic chuck which is an example of the ceramic substrate of the present invention.

FIG. 6 is a partially enlarged sectional view schematically showing a ceramic substrate constituting the electrostatic chuck shown in FIG. 5;

FIG. 7 is a horizontal sectional view schematically showing an example of an electrostatic electrode embedded in a ceramic substrate.

FIG. 8 is a horizontal sectional view schematically showing another example of an electrostatic electrode embedded in a ceramic substrate.

FIG. 9 is a horizontal sectional view schematically showing still another example of an electrostatic electrode embedded in a ceramic substrate.

FIGS. 10A to 10D are cross-sectional views schematically illustrating an example of a method for manufacturing a hot plate, which is an example of the ceramic substrate of the present invention.

[Explanation of symbols]

 Reference Signs List 10 hot plate 11 ceramic substrate 11a heating surface 11b bottom surface 12 resistance heating element 120 end of resistance heating element 13, 13 'through hole 14 bottomed hole 15 through hole 17 other ceramic body (cylindrical body) 18 conductive circuit 19 blind hole 130 Via hole 180 Temperature measuring element

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H01L 21/68 H05B 3/16 5F056 H05B 3/16 3/18 3/18 H01L 21/30 503A 567 541L F term (reference) ) 3K092 PP20 QB03 QB08 QB18 QB44 QB45 QB68 QB74 QB76 RF03 RF11 RF17 RF22 RF27 TT30 VV09 4G026 BB02 BB16 BE03 BG02 BH06 4K030 GA02 KA23 KA46 5F031 CA02 HA02 HA03 HA16 HA17 HA37 5F046 CC

Claims (8)

[Claims] 1. A ceramic substrate provided with a conductor on the surface or inside thereof, wherein the ceramic substrate comprises
A ceramic substrate comprising ₂ O ₃ . 2. The ceramic substrate according to claim 1, wherein another ceramic body is joined to a bottom surface of the ceramic substrate. 3. The ceramic substrate according to claim 1, wherein the conductor is a resistance heating element and functions as a hot plate. 4. The ceramic substrate according to claim 1, wherein the conductor is an electrostatic electrode and functions as an electrostatic chuck. 5. A method for manufacturing a joined body in which another ceramic body is joined to a bottom surface of a ceramic substrate provided with a conductor therein, wherein the other ceramic body is made of Y ₂ O _3.
And heating the other ceramic body and the ceramic substrate in a state in which the ceramic substrate is in contact with the ceramic substrate. 6. The method for manufacturing a joined body according to claim 5, wherein the heating is performed at 1500 to 2000 ° C. in a state where the other ceramic body and the ceramic substrate are in contact with each other. 7. The method according to claim 5, wherein the conductor is a resistance heating element, and the ceramic substrate functions as a hot plate. 8. The method according to claim 5, wherein the conductor is an electrostatic electrode, and the ceramic substrate functions as an electrostatic chuck.