JP2001298074A - Ceramic substrate for device for manufacturing and inspection semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic substrate for a device for manufacturing and inspection a semiconductor capable of ensuring good sealing and dielectric strength even at high temperature, and improving fracture toughness and relaxing baking conditions because a large pore size is allowable. SOLUTION: The ceramic substrate for a device for manufacturing and inspecting a semiconductor has a conductive material formed on or in a ceramic substrate containing carbon having a peak near 1550 cm-1 and 1333 cm-1 in a Raman spectrum. The ceramic has pores with maximum diameter of 50 μm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate for a semiconductor manufacturing / inspection apparatus such as an electrostatic chuck, a hot plate (ceramic heater), a wafer prober and the like mainly used in the semiconductor industry.

DETAILED DESCRIPTION OF THE INVENTION

[0002]

2. Description of the Related Art Semiconductors are extremely important products required in various industries.
The silicon wafer is manufactured by slicing a silicon single crystal to a predetermined thickness to produce a silicon wafer, and then forming a plurality of integrated circuits and the like on the silicon wafer.

In the manufacturing process of this semiconductor chip,
For example, on a silicon wafer placed on an electrostatic chuck,
Various processes such as etching and CVD are performed to form conductor circuits and elements. At that time, gas for deposition,
Since corrosive gases are used as an etching gas or the like, it is necessary to protect the electrostatic electrode layer from corrosion by these gases. Therefore, the electrostatic electrode layer is usually covered and protected by a ceramic dielectric film or the like. This ceramic dielectric film requires a large withstand voltage in order to prevent a short circuit between the silicon wafer and the electrostatic electrode due to dielectric breakdown of the ceramic dielectric film during the operation of the electrostatic chuck.

[0004]

Conventionally, a nitride ceramic has been used as a material for forming the ceramic dielectric film. However, a dielectric film made of the nitride ceramic is required to have a sufficient withstand voltage. In order to prevent this, in order to prevent a decrease in the withstand voltage due to gas or the like in the pores, it is necessary to make the pore diameter of the largest pore as extremely small as 5 μm or less, for example, as disclosed in JP-A-5-8140. And it was.

On the other hand, as described in Japanese Patent Application Laid-Open No. 9-48668, it has been necessary to add carbon to such an electrostatic chuck to secure the concealing property. However, since carbon has electrical conductivity, the maximum pore size is 5 μm.
A new problem arises in that the withstand voltage cannot be ensured even if it is extremely small as m or less. Such a problem occurs not only in the electrostatic chuck but also in a wafer prober and a hot plate.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the carbon to be added is not crystalline carbon as described in JP-A-9-48668. It has been newly found that by providing the amorphous property, the withstand voltage can be ensured even if the pore diameter of the maximum pore is 50 μm.

That is, the present invention relates to a ceramic substrate.
Ceramic substrate with conductor formed on or inside surface
In the above, the ceramic substrate has a Raman spectrum
1550cm^-1And 1333cm ^-1Has peak near
Made of ceramic containing carbon
No or no pores in the mick
In this case, the pore diameter of the largest pore is 50 μm or less.
Ceramic substrate for semiconductor manufacturing and inspection equipment
It is.

It is desirable that the amount of carbon is 5 to 5000 ppm. The ceramic is desirably at least one selected from nitride ceramics, oxide ceramics, and carbide ceramics. The ceramic substrate has a diameter of 200 mm or more and a thickness of 25 mm.
It is desirable that: If the diameter is less than 200 mm or the thickness exceeds 25 mm, no warpage occurs, and the present invention is most effective in this range. The ceramic substrate desirably has a plurality of lifter pin through holes. 100-700 ° C when having through holes
In this case, when the Young's modulus of the ceramic decreases, the processing strain is released, and warpage occurs. The ceramic substrate is desirably used at 100 to 700 ° C. This is because the withstand voltage is reduced in such a temperature range.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A ceramic substrate for a semiconductor manufacturing / inspection apparatus of the present invention (hereinafter also referred to as a ceramic substrate) is
1550 cm ^-1 and 1333 cm in Raman spectrum
It is necessary to be made of a ceramic containing carbon having a peak near ^-1 . 155 in Raman spectrum
In the vicinity of 0 cm ⁻¹ , a peak attributable to the crystalline portion, 133
A peak due to the amorphous portion appears at around 3 cm ^-1 . The term “crystalline portion” and “amorphous portion” used herein include not only the case where a crystalline body and an amorphous body are simply mixed, but also those where the crystallinity is reduced and the amorphous body is formed.

The expression "near" is used because there is a slight error in the appearance position of the peak of the laser Raman, and it is 1550 cm ^-1 and 1333 cm.
^The peak appearing around ^-1 is originally 1550
the meaning of a peak appearing in cm ^-1 and 1333 cm ^-1.

[0011] In the ceramic substrate of the present invention uses a ceramic containing carbon having a peak near 1550 cm ^-1 and 1333 cm ^-1 in the Raman spectrum, can be lowered electrical conductivity because it has an amorphous structure,
High volume resistivity at high temperature and maximum pore diameter of 50
With a thickness of up to μm, a withstand voltage at high temperatures can be ensured.

As described above, since the restriction on the size of the pore diameter is relaxed as compared with the conventional case, it is not necessary to set the manufacturing conditions strictly, and the electrostatic chuck can be manufactured at a lower cost than the conventional case. Further, by introducing pores, the fracture toughness value can be increased. In the ceramic substrate of the present invention, no pores are present, or when pores are present, the pore diameter of the largest pore is 50 μm or less. When no pores are present, the withstand voltage at high temperatures is particularly high,
Conversely, when pores are present, the fracture toughness value increases. Or either the design for this may be determined in consideration of the required properties.

The reason why the fracture toughness value is increased by the presence of the pores is not clear, but it is presumed that the extension of the crack is stopped by the pores. In the ceramic substrate of the present invention, the pore diameter of the maximum pore needs to be 50 μm or less. If the pore diameter of the maximum pore exceeds 50 μm, the withstand voltage characteristics at 100 to 700 ° C., particularly at 200 ° C. or higher, cannot be secured. The pore diameter of the largest pore is desirably 10 μm or less. 100-700 ° C, especially 2
This is because the amount of warping at 00 ° C. or higher is reduced.

The porosity and the maximum pore diameter are adjusted by the pressurizing time, pressure, temperature, and additives such as SiC and BN during sintering. Since SiC and BN hinder sintering, pores can be introduced. For the measurement of the maximum pore diameter, five samples were prepared, and the surface thereof was mirror-polished.
This is performed by photographing the surface at 10 places with an electron microscope at a magnification of 000 times. Then, the maximum pore diameter is selected from the photographed images, and the average of 50 shots is defined as the maximum pore diameter.

In the above ceramic substrate, 0.05 to 1
It is desirable to contain 0% by weight of oxygen, particularly 0.1 to 5% by weight of oxygen. In particular, if the amount is less than 0.1% by weight, the withstand voltage cannot be ensured in some cases. On the other hand, if the amount exceeds 5% by weight, the withstand voltage still decreases due to a decrease in the high temperature withstand voltage characteristics of the oxide. Because there is. On the other hand, if the oxygen content exceeds 5% by weight, the thermal conductivity may decrease, and the temperature raising / lowering characteristics may decrease. In order to make the ceramic contain oxygen, the raw material powder of the ceramic is usually heated in the air or oxygen, or the raw material powder is mixed with a metal oxide and fired. Examples of the metal oxide include yttria (Y ₂ O ₃ ), alumina (Al ₂ O ₃ ), rubidium oxide (Rb ₂ O), lithium oxide (Li ₂ O), and calcium carbonate (CaCO ₃ ).
And the like. The addition amount of these metal oxides is preferably 1 to 10 parts by weight based on 100 parts by weight of the ceramic.

The porosity is measured by the Archimedes method. Pulverize the sintered body, put the pulverized material in an organic solvent or mercury, measure the volume, calculate the true specific gravity from the weight and volume of the pulverized material, and calculate the porosity from the true specific gravity and the apparent specific gravity .

Here, laser Raman spectrum analysis of a carbon material will be described. Raman spectrum refers to the spectrum of scattered light that appears due to the Raman effect. When a substance is irradiated with monochromatic light having a constant frequency, the scattered light has a different wavelength from the radiated light. Is included.

When a carbon material is irradiated with a laser beam of a predetermined wavelength, a Raman effect occurs and a laser Raman spectrum is observed. Since the Raman spectrum is light generated in association with crystal vibration and the like, the Raman spectrum of the material is A spectrum having a wavelength depending on crystallinity can be detected.

That is, in the case of crystalline carbon (graphite), a spectrum is detected at around 1550 cm ⁻¹ , and in the case of amorphous carbon, 1333 cm ⁻¹ is detected.
A peak is detected near cm ⁻¹ . Therefore, it can be said that carbon whose peak is detected at around 1333 cm ^-1 is carbon having low crystallinity. Note that the peak includes a broad peak called a halo.

This low-crystalline carbon, unlike crystalline carbon, has a low electrical conductivity. Therefore, even if such carbon is contained in, for example, a ceramic dielectric film, the carbon of the ceramic dielectric film does not. High temperature area (for example, 50
(Near 0 ° C.), the decrease in volume resistivity is suppressed. Therefore, even if the ceramic dielectric film has pores as large as 50 μm or less, it has excellent withstand voltage. Further, the ceramic dielectric film is blackened because it contains carbon, so that high radiant heat can be obtained and the electrostatic electrode existing under the ceramic dielectric film can be hidden.

The carbon content is 5 to 5000 ppm
Is preferred. If the carbon content is less than 5 ppm, radiant heat is reduced, and it is difficult to conceal the electrostatic electrode.
If it exceeds pm, it is difficult to suppress a decrease in volume resistivity. The carbon content is preferably between 50 and 2000
ppm is preferred.

In order to make the carbon in the ceramic dielectric film amorphous, when a raw material powder, a resin or the like, and a solvent are mixed to produce a molded body, the resin is hardly crystalline even when heated. Or a carbohydrate may be added, and the molded body may be degreased in an atmosphere containing less oxygen or a non-oxidizing atmosphere.

The ceramic substrate of the present invention can be used for manufacturing semiconductors.
It can be used for inspection, and more specifically, it can be used for electrostatic chucks, hot plates (ceramic heaters), wafer probers, and the like. The thickness of the ceramic substrate of the present invention is desirably 50 mm or less, particularly preferably 25 mm or less. In particular, when the thickness of the ceramic substrate exceeds 25 mm, the heat capacity of the ceramic substrate becomes large. In particular, when the temperature control means is provided for heating and cooling, the temperature followability is reduced due to the large heat capacity. Further, the problem of warpage caused by the presence of pores solved by the ceramic substrate of the present invention is because it is unlikely to occur with a thick ceramic substrate having a thickness exceeding 25 mm. Particularly, 5 mm or less is optimal. The thickness is desirably 1 mm or more.

The diameter of the ceramic substrate of the present invention is 200 m
m or more is desirable. In particular, it is desirable to be 12 inches (300 mm) or more. This is because it will become the mainstream of next-generation semiconductor wafers. In addition, the above-mentioned problem of warpage is caused by a diameter of 20 mm.
This is because it hardly occurs on a ceramic substrate having a thickness of 0 mm or less.

The ceramic constituting the ceramic substrate of the present invention is desirably at least one selected from nitride ceramics, oxide ceramics, and carbide ceramics. Examples of the nitride ceramic include metal nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, and titanium nitride. Examples of the oxide ceramic include alumina, silica, and mullite. Examples of the carbide ceramic include silicon carbide, boron carbide, tungsten carbide, molybdenum carbide and the like.

In the present invention, it is desirable to include a sintering aid in the ceramic substrate. As sintering aids,
Alkali metal oxides, alkaline earth metal oxides, can be used rare earth oxides, and among these sintering aids, particularly _{CaO, Y 2 O 3, Na} 2 O, Li 2 O, R
b ₂ O is preferred. Also, alumina may be used.
The content of these is desirably 0.1 to 20% by weight.

In the ceramic substrate of the present invention, the semiconductor wafer is placed in contact with the wafer mounting surface of the ceramic substrate, and the semiconductor wafer is supported by lifter pins or the like, as shown in FIG. In some cases, it is held at a certain distance from the ceramic substrate.

FIG. 13 is a partially enlarged sectional view schematically showing a ceramic heater which is an example of the ceramic substrate of the present invention. In FIG. 13, lifter pins 96 are inserted through through holes 95 and hold silicon wafer 99. By moving the lifter pins 96 up and down, it is possible to receive the silicon wafer 99 from the transfer device, place the silicon wafer 99 on the ceramic substrate 91, and heat while supporting the silicon wafer 99. A heating element 92 is formed on the bottom surface 91 a of the ceramic substrate 91, and a metal coating layer 92 a is provided on the surface of the heating element 92. A bottomed hole 94 is provided, into which a thermocouple is inserted. The silicon wafer 99 is heated on the wafer heating surface 91b side.

The ceramic substrate of the present invention is a ceramic substrate for a semiconductor manufacturing / inspection apparatus used in an apparatus for manufacturing a semiconductor or inspecting a semiconductor. Specific examples of the apparatus include an electrostatic chuck and a wafer. Probers, hot plates, susceptors, and the like. When used as a hot plate (ceramic heater), the conductor is a heating element, and may be a metal layer of about 0.1 to 100 μm or a heating wire. When used as an electrostatic chuck, the conductor is an electrostatic electrode and RF
The electrode and the heating element may be formed below the electrostatic electrode as a conductor in the ceramic substrate. Further, when used as a wafer prober, a chuck top conductor layer is formed as a conductor on the surface, and a guard electrode and a ground electrode are formed as conductors inside. The ceramic substrate of the present invention has a temperature of 150 ° C. or more,
Desirably, it is optimally used at 200 ° C. or higher.

Hereinafter, the present invention will be described with reference to an electrostatic chuck and a wafer prober having a hot plate function.
FIG. 1 is a longitudinal sectional view schematically showing an electrostatic chuck which is an embodiment of the ceramic substrate of the present invention, and FIG.
FIG. 3 is a sectional view taken along line AA of the electrostatic chuck shown in FIG. 1, and FIG. 3 is a sectional view taken along line BB of the electrostatic chuck shown in FIG. 1.
It is a line sectional view.

In this electrostatic chuck 101, a chuck positive electrode electrostatic layer 2 is formed on the surface of a ceramic substrate 1 having a circular shape in plan view.
And a chuck negative electrode electrostatic layer 3 are formed, and a ceramic dielectric film 4 made of a nitride ceramic containing amorphous carbon is formed so as to cover the electrostatic electrode layer. ing. A silicon wafer 9 is placed on the electrostatic chuck 101 and is grounded.

As shown in FIG. 2, the chuck positive electrode electrostatic layer 2 is composed of a semicircular arc portion 2a and a comb tooth portion 2b, and the chuck negative electrode electrostatic layer 3 is also a semicircular arc portion 3a and a comb tooth portion. Part 3b
The chuck positive electrode electrostatic layer 2 and the chuck negative electrode electrostatic layer 3 are arranged to face each other so as to intersect the comb teeth portions 2b and 3b. Each of the negative electrode electrostatic layers 3 has a DC power supply of +
The side - the side are connected, the DC voltage V ₂ is adapted to be applied. Since the ceramic dielectric film 4 contains carbon, the chuck positive electrode electrostatic layer 2 and the chuck negative electrode electrostatic layer 3 are hidden.

In order to control the temperature of the silicon wafer 9, a resistance heating element 5 having a concentric circular shape as shown in FIG. 3 is provided inside the ceramic substrate 1. at both ends of the external terminal pin 6 is connected, is fixed, so that the voltages V ₁ is applied. Although not shown in FIGS. 1 and 2, the ceramic substrate 1 has a bottomed hole 11 for inserting a temperature measuring element and a lifter pin for supporting and lowering the silicon wafer 9 as shown in FIG. (Not shown) through hole 12 for insertion
Are formed. Note that the resistance heating element 5 may be formed on the bottom surface of the ceramic substrate.

When the electrostatic chuck 101 is operated, a DC voltage V ₂ is applied to the chuck positive electrostatic layer 2 and the chuck negative electrostatic layer 3. Thereby, the silicon wafer 9 is adsorbed and fixed to these electrodes via the ceramic dielectric film 4 by the electrostatic action of the chuck positive electrode electrostatic layer 2 and the chuck negative electrode electrostatic layer 3. Become. After fixing the silicon wafer 9 on the electrostatic chuck 101 in this manner, various processes such as CVD are performed on the silicon wafer 9.

The electrostatic chuck according to the present invention has, for example, a configuration as shown in FIGS. Hereinafter, each member constituting the electrostatic chuck, and
Other embodiments of the electrostatic chuck according to the present invention will be sequentially described in detail.

The ceramic dielectric film used in the electrostatic chuck of the present invention has a Raman spectrum of 1 as described above.
A ceramic containing amorphous carbon having a peak near 550 cm ^-1 and 1333 cm ^-1, pore diameter of the maximum pores is 50μm or less. Further, its thickness is desirably 50 to 1500 μm.

The ceramic is desirably at least one selected from nitride ceramics, oxide ceramics, and carbide ceramics. Examples of the nitride ceramic include metal nitride ceramics, for example, aluminum nitride, silicon nitride, boron nitride, titanium nitride, and the like. Of these, aluminum nitride is most preferred. This is because the withstand voltage is high and the thermal conductivity is the highest at 180 W / m · K. As the above oxide ceramic,
For example, alumina, silica, mullite and the like can be mentioned.
As the carbide ceramic, for example, silicon carbide,
Examples include boron carbide, tungsten carbide, molybdenum carbide, and the like.

The above ceramic has a Raman spectrum of 1
It contains amorphous carbon having peaks near 550 cm ⁻¹ and 1333 cm ⁻¹ . This amorphous carbon has low electric conductivity unlike crystalline carbon. Therefore, such an amorphous carbon-containing ceramic does not decrease in volume resistivity even in a high-temperature region, and therefore has a higher withstand voltage than conventional ceramics.

Peak intensity ratio: I (1550) / I (13
55) is desirably 100 or less. This is because if it exceeds 100, it becomes close to a single crystal.

The ceramic dielectric film has a maximum pore diameter of 50 μm or less. In addition, the thickness is 50-
The thickness is preferably 1500 μm, and the porosity is preferably 5% or less. If the thickness of the ceramic dielectric film is less than 50 μm, a sufficient withstand voltage cannot be obtained because the film thickness is too small, and the dielectric breakdown of the ceramic dielectric film occurs when a silicon wafer is placed and adsorbed. On the other hand, if the thickness of the ceramic dielectric film exceeds 1500 μm, the distance between the silicon wafer and the electrostatic electrode is increased, and the ability to adsorb the silicon wafer is reduced. The thickness of the ceramic dielectric film is preferably 100 to 1500 μm.

If the porosity exceeds 5%, the number of pores increases, and the pore diameter becomes too large.
The pores are easily communicated with each other. With a ceramic dielectric film having such a structure, the withstand voltage is reduced. further,
When the pore diameter of the largest pore exceeds 50 μm, it is not possible to ensure a withstand voltage at high temperatures even if the oxide exists at the grain boundary. The porosity is preferably 0.01% to 3%, and the maximum pore diameter is preferably 0.1 μm to 10 μm.

In the electrostatic chuck according to the present invention, pores may be present to some extent in the ceramic dielectric film because the fracture toughness value can be increased, and the thermal shock resistance Can be improved.

Examples of the electrostatic electrode formed on the ceramic substrate include a sintered body of metal or conductive ceramic, a metal foil, and the like. The metal sintered body is preferably made of at least one selected from tungsten and molybdenum. It is desirable that the metal foil is also made of the same material as the metal sintered body. This is because these metals are relatively hard to be oxidized and have sufficient conductivity as electrodes.
As the conductive ceramic, at least one selected from carbides of tungsten and molybdenum can be used.

FIGS. 8 and 9 are horizontal sectional views schematically showing electrostatic electrodes of another electrostatic chuck.
In the electrostatic chuck 20 shown in FIG. 1, a semicircular chuck positive electrode electrostatic layer 22 and a chuck negative electrode electrostatic layer 23 are formed inside the ceramic substrate 1. In the electrostatic chuck shown in FIG. Inside are formed chuck positive electrostatic layers 32a and 32b and chuck negative electrostatic layers 33a and 33b each having a shape obtained by dividing a circle into four parts. Also, two positive electrode electrostatic layers 22a and 22b and two chuck negative electrode electrostatic layers 3
3a and 33b are formed 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.

The ceramic substrate used in the electrostatic chuck according to the present invention is desirably made of at least one selected from nitride ceramics, oxide ceramics, and carbide ceramics.

Examples of the nitride ceramic include metal nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, and titanium nitride. Further, it is desirable that the ceramic dielectric film and the ceramic substrate are made of the same material. Nitride ceramics have high thermal conductivity,
This is because heat generated by the resistance heating element can be transmitted well. Further, when the ceramic dielectric film and the ceramic substrate are made of the same material, an electrostatic chuck can be easily manufactured by laminating green sheets manufactured by the same method and firing them under the same conditions. .
Also, among nitride ceramics, aluminum nitride is most preferred. This is because the thermal conductivity is the highest at 180 W / m · K. As the oxide ceramic, for example,
Alumina, silica, mullite and the like can be mentioned. Examples of the carbide ceramic include silicon carbide, boron carbide, tungsten carbide, molybdenum carbide and the like.

When the ceramic substrate of the present invention is used for a ceramic heater, the semiconductor wafer and the heating surface can be separated. Separation distance is 50-5000 μm
Is desirable. In addition, the present invention is particularly effective in such a case. This is because the amount of warpage of the ceramic substrate at high temperatures is small, and the distance between the semiconductor wafer and the heating surface becomes uniform. In the present invention, the volume resistivity is 450
Desirably, it exceeds 1 × 10 ⁸ Ω · cm at a temperature of ° C. This is because withstand voltage at 100 to 700 ° C. can be ensured even if the maximum pore diameter is 50 μm.

The electrostatic chuck according to the present invention is generally provided with a temperature control means such as a resistance heating element as shown in FIG. This is because it is necessary to perform a CVD process or the like while heating the silicon wafer placed on the electrostatic chuck.

As the temperature control means, in addition to the resistance heating element 5 shown in FIG. 3, a Peltier element (see FIG. 6) can be used. The resistance heating element may be provided inside the ceramic substrate, or may be provided on the bottom surface of the ceramic substrate. When a resistance heating element is provided, a blowing port for a refrigerant such as air may be provided as a cooling means in a support container into which the electrostatic chuck is fitted.

When the resistance heating element is provided inside the ceramic substrate, a plurality of layers may be provided. In this case, it is desirable that the patterns of the respective layers are formed so as to complement each other, and that the pattern is formed on any layer when viewed from the heating surface. For example, the structure is a staggered arrangement.

Examples of the resistance heating element include a sintered body of metal or conductive ceramic, a metal foil, a metal wire, and the like. As the metal sintered body, at least one selected from tungsten and molybdenum is preferable. This is because these metals are relatively hard to oxidize and have a resistance value sufficient to generate heat.

The conductive ceramic may be at least one selected from carbides of tungsten and molybdenum.
Seeds can be used. Further, when a resistance heating element is formed on the bottom surface of the ceramic substrate, it is desirable to use a noble metal (gold, silver, palladium, platinum) or nickel as the metal sintered body. Specifically, silver, silver-palladium, or the like can be used. The metal particles used in the metal sintered body may be spherical, scaly, or a mixture of spherical and scaly.

A metal oxide may be added to the metal sintered body. The use of the metal oxide is for bringing the ceramic substrate and the metal particles into close contact. Although the reason why the metal oxide improves the adhesion between the ceramic substrate and the metal particles is not clear, the surface of the metal particles has a slight oxide film formed thereon, and the ceramic substrate is formed of an oxide. Of course, even in the case of a non-oxide ceramic, an oxide film is formed on the surface. Therefore, it is considered that this oxide film is sintered and integrated on the surface of the ceramic substrate via the metal oxide, so that the metal particles and the ceramic substrate adhere to each other.

As the metal oxide, for example, oxidized
Lead, zinc oxide, silica, boron oxide (B _Two O_Three ), Al
At least one selected from Mina, Yttria and Titania
Species are preferred. These oxides have the resistance value of the resistance heating element.
Between the metal particles and the ceramic substrate without increasing the
This is because adhesion can be improved.

The amount of the metal oxide is desirably from 0.1 to less than 10 parts by weight based on 100 parts by weight of the metal particles. By using a metal oxide in this range,
This is because the resistance value does not become too large and the adhesion between the metal particles and the ceramic substrate can be improved.

The ratio of lead oxide, zinc oxide, silica, boron oxide (B ₂ O ₃ ), alumina, yttria, and titania is such that when the total amount of metal oxide is 100 parts by weight, 10 parts by weight, 1 to 30 parts by weight of silica, 5 to 50 parts by weight of boron oxide, 20 to 7 parts of zinc oxide
0 parts by weight, alumina 1 to 10 parts by weight, yttria 1
-50 parts by weight and titania of 1-50 parts by weight are preferred.
However, it is desirable that the total be adjusted so that the total does not exceed 100 parts by weight. This is because these ranges can particularly improve the adhesion to the ceramic substrate.

When the resistance heating element is provided on the bottom surface of the ceramic substrate, it is desirable that the surface of the resistance heating element 15 be covered with a metal layer 150 (see FIG. 4). The resistance heating element 15 is a sintered body of metal particles, and is easily oxidized when exposed, and the oxidation changes the resistance value. Therefore, by covering the surface with the metal layer 150, oxidation can be prevented.

The thickness of the metal layer 150 is 0.1 to 10 μm
Is desirable. This is because the oxidation of the resistance heating element can be prevented without changing the resistance value of the resistance heating element. The metal used for coating may be a non-oxidizing metal. Specifically, gold, silver, palladium, platinum,
At least one selected from nickel is preferred.
Among them, nickel is more preferable. The resistance heating element requires a terminal for connection to a power supply, and this terminal is attached to the resistance heating element via solder. Nickel prevents thermal diffusion of the solder. As connection terminals, terminal pins made of Kovar can be used.

When the resistance heating element is formed inside the heater plate, the surface of the resistance heating element is not oxidized, so that the coating is unnecessary. When the resistance heating element is formed inside the heater plate, a part of the surface of the resistance heating element may be exposed.

As the metal foil used as the resistance heating element, it is desirable to use a nickel foil or a stainless steel foil which is patterned by etching or the like to form a resistance heating element. The patterned metal foil may be bonded with a resin film or the like. Examples of the metal wire include a tungsten wire and a molybdenum wire.

When a Peltier element is used as the temperature control means, heat is generated by changing the direction of current flow.
This is advantageous because both cooling can be performed. As shown in FIG. 6, the Peltier element 8 is composed of p-type and n-type thermoelectric elements 81.
Are connected in series and joined to a ceramic plate 82 or the like. Examples of the Peltier element include a silicon-germanium-based material, a bismuth-antimony-based material, and a lead / tellurium-based material.

In the electrostatic chuck according to the present invention, for example, as shown in FIG. 1, a chuck positive electrostatic layer 2 and a chuck negative electrostatic layer 3 are provided between a ceramic substrate 1 and a ceramic dielectric film 4. An electrostatic chuck 101 having a configuration in which a resistance heating element 5 is provided inside a ceramic substrate 1;
As shown in FIG. 4, a chuck positive electrostatic layer 2 and a chuck negative electrostatic layer 3 are provided between a ceramic substrate 1 and a ceramic dielectric film 4, and a resistance heating element 15 is provided on the bottom surface of the ceramic substrate 1. Electrostatic chuck 201 having the configuration shown in FIG.
As shown in FIG. 2, a chuck positive electrode electrostatic layer 2 and a chuck negative electrode electrostatic layer 3 are provided between a ceramic substrate 1 and a ceramic dielectric film 4, and a metal wire 7 serving as a resistance heating element is provided inside the ceramic substrate 1. Chuck 30 having a structure in which is embedded
1. As shown in FIG. 6, a chuck positive electrostatic layer 2 and a chuck negative electrostatic layer 3 are provided between a ceramic substrate 1 and a ceramic dielectric film 4, and a thermoelectric element 81 is provided on the bottom surface of the ceramic substrate 1. Peltier element 8 made of ceramic plate 82
And the like.

In the electrostatic chuck according to the present invention, FIGS.
As shown in FIG. 2, the chuck positive electrode electrostatic layer 2 and the chuck negative electrode electrostatic layer 3 are provided between the ceramic substrate 1 and the ceramic dielectric film 4, and the resistance heating element 5 and the metal wires are provided inside the ceramic substrate 1. 7 are formed, connecting portions (through holes) 16, 1, and 1 for connecting these to external terminals.
7 is required. The through holes 16 and 17 are made of a high melting point metal such as tungsten paste and molybdenum paste,
It is formed by filling a conductive ceramic such as tungsten carbide or molybdenum carbide.

Also, the connection portions (through holes) 16 and 17
Is preferably 0.1 to 10 mm. This is because cracks and distortion can be prevented while preventing disconnection. The external terminal pins 6 and 18 are connected using the through holes as connection pads (see FIG. 7D).

The connection is made by solder or brazing material. As brazing materials, silver brazing, palladium brazing, aluminum brazing,
Use gold brazing. As the gold solder, an Au-Ni alloy is desirable. This is because the Au-Ni alloy has excellent adhesion to tungsten.

The ratio of Au / Ni is [81.5-82.
5 (% by weight)] / [18.5 to 17.5 (% by weight)] is desirable. The thickness of the Au—Ni layer is desirably 0.1 to 50 μm. This is because the range is sufficient to secure the connection.
Moreover, 500-1000 at a high vacuum of 10 ^-6 to 10 ^-5 Pa.
When used at high temperature of ℃, Au-Cu alloy deteriorates,
An Au-Ni alloy is advantageous without such deterioration.
The total amount of impurity elements in the Au—Ni alloy is 100%.
It is desirable that the amount be less than 1 part by weight when it is used as a part by weight.

In the ceramic substrate of the present invention, a thermocouple can be embedded in the bottomed hole 12 of the ceramic substrate 1 as necessary. 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 metal wires of the thermocouple is preferably equal to or larger than the element diameter of each metal 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. Therefore, the temperature controllability is improved and the temperature distribution on the heating surface of the semiconductor wafer is reduced. As the thermocouple, for example, JIS-C-1602 (198
0), K type, R type, B type, S type, E type
Type, J type, and T type thermocouples.

FIG. 10 is a cross-sectional view schematically showing a supporting container 41 for disposing the electrostatic chuck of the present invention having the above-described structure. The support container 41 includes the electrostatic chuck 1
01 is fitted through the heat insulating material 45. In addition, the support container 11 has a refrigerant outlet 42.
Is formed, and the refrigerant is blown from the refrigerant injection port 44 and goes out of the suction port 43 through the refrigerant discharge port 42, and the electrostatic chuck 101 is cooled by the action of the refrigerant. You can do it.

Next, an example of a method for manufacturing an electrostatic chuck according to the present invention will be described with reference to the sectional view shown in FIG. (1) First, an amorphous carbon is produced. For example,
A pure amorphous carbon is produced by calcining a hydrocarbon consisting of only C, H, and O, preferably a saccharide (sucrose or cellulose) at 300 to 500 ° C in the air.
Amorphous carbon has a Raman spectrum of 1550 cm
^-1 and 1333 cm ^-1 near the peak (1333 cm ^-1
May be a halo). Incidentally, carbon peaks around 1550 cm ^-1 and 1333 cm ^-1 in the Raman spectrum appears is obtained even if the acrylic binder is thermally decomposed. For example, an acrylic resin binder (SA-545 series manufactured by Mitsui Chemicals, Inc., acid value 0.
5) and acrylic resin binder (Kyoeisha brand name K
C-600 series acid number 17) can be used.

The green sheet 50 is obtained by mixing the ceramic powder of the nitride ceramic with the above amorphous carbon, binder and solvent. As the above-mentioned ceramic powder, for example, aluminum nitride or the like can be used, and a sintering aid such as yttria may be added as necessary.

Since several or one green sheet 50 ′ to be laminated on the green sheet on which the electrostatic electrode layer printed body 51 described later is formed is a layer to be the ceramic dielectric film 4, It is assumed that amorphous carbon powder is mixed with the material powder. Usually, it is desirable to use the same material for the ceramic dielectric film 4 and the material for the ceramic substrate 1. This is because these are often sintered together, and the firing conditions are the same. However, when the materials are different, it is also possible to manufacture a ceramic substrate first, form an electrostatic electrode layer thereon, and further form a ceramic dielectric film thereon.

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. A paste obtained by mixing these is formed into a sheet shape by a doctor blade method to produce a green sheet 50.

The green sheet 50 may be provided with a through hole for inserting a lifter pin of a silicon wafer or a concave portion for burying a thermocouple as necessary. The through holes and the concave portions can be formed by punching or the like. The thickness of the green sheet 50 is preferably about 0.1 to 5 mm.

Next, a conductor paste serving as an electrostatic electrode layer and a resistance heating element is printed on the green sheet 50. The printing is performed so as to obtain a desired aspect ratio in consideration of the shrinkage ratio of the green sheet 50, thereby obtaining the electrostatic electrode layer print body 51 and the resistance heating element layer print body 52. The printed body is formed by printing a conductive paste containing conductive ceramic, metal particles, and the like.

As the conductive ceramic particles contained in these conductor pastes, carbides of tungsten or molybdenum are most suitable. This is because it is hard to be oxidized and the thermal conductivity is hard to decrease. Further, as the metal particles, for example, tungsten, molybdenum, platinum, nickel and the like can be used.

The average particle size of the conductive ceramic particles and metal particles is preferably 0.1 to 5 μm. This is because it is difficult to print the conductor paste when these particles are too large or too small.

As such a paste, 85 to 97 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, α- A paste for a conductor prepared by mixing 1.5 to 10 parts by weight of at least one solvent selected from terpineol, glycol, ethyl alcohol and butanol is most suitable. Further, the holes formed by punching or the like are filled with a conductor paste to obtain through-hole prints 53 and 54.

Next, as shown in FIG.
A green sheet 50 having 1, 52, 53, 54;
A green sheet 50 'having no printed body is laminated.
On the green sheet on which the electrostatic electrode layer printed body 51 is formed, several or one green sheet 50 'is laminated. The reason why the green sheet 30 'having no printed body is laminated on the resistance heating element forming side is to prevent the end face of the through hole from being exposed and being oxidized during firing for forming the resistance heating element. is there. If baking for forming the resistance heating element is performed while the end face of the through hole is exposed, it is necessary to sputter a metal that is difficult to oxidize, such as nickel, and more preferably to coat it with Au-Ni gold solder. Is also good.

(2) Next, as shown in FIG. 7B, the laminate is heated and pressed to sinter the green sheet and the conductive paste. Heating temperature is 1000-20
The temperature and the pressure are preferably 100 to 200 kg / cm ^{2 at} 00 ° C., and the heating and pressurization are performed in an inert gas atmosphere. As the inert gas, argon, nitrogen, or the like can be used. In this step, the through holes 16, 1
7, a chuck positive electrode electrostatic layer 2, a chuck negative electrode electrostatic layer 3, a resistance heating element 5, and the like are formed.

(3) Next, as shown in FIG. 7C, blind holes 13 and 14 for connecting external terminals are provided. Blind hole 1
At least a part of the inner walls of the electrodes 3 and 14 are made conductive, and the conductive inner walls are connected to the chuck positive electrostatic layer 2, the chuck negative electrostatic layer 3, the resistance heating element 5, and the like. desirable.

(4) Finally, as shown in FIG.
External terminals 6 and 18 are provided in blind holes 13 and 14 via a brazing filler metal. Further, if necessary, a bottomed hole 12 can be provided, and a thermocouple can be embedded therein.

As the solder, alloys such as silver-lead, lead-tin, bismuth-tin and the like can be used. Note that the thickness of the solder layer is desirably 0.1 to 50 μm. This is because the range is sufficient to secure the connection by soldering.

In the above description, the electrostatic chuck 101
(See FIG. 1), the electrostatic chuck 201 (see FIG.
In the case of manufacturing, a ceramic plate having an electrostatic electrode layer is manufactured, and then a conductive paste is printed and fired on the bottom surface of the ceramic plate to form a resistance heating element 15, and thereafter, electroless plating or the like is performed. May be used to form the metal layer 150. When the electrostatic chuck 301 (see FIG. 5) is manufactured, a metal foil or a metal wire may be embedded in ceramic powder as an electrostatic electrode or a resistance heating element and sintered. Further, when manufacturing the electrostatic chuck 401 (see FIG. 6), after manufacturing a ceramic plate having an electrostatic electrode layer, a Peltier element may be joined to this ceramic plate via a sprayed metal layer.

When a conductor is provided on the surface and inside of the ceramic substrate of the present invention, and when the inside conductor is at least one of a guard electrode and a ground electrode, the ceramic substrate is provided with a wafer prober. Function as

FIG. 14 is a cross-sectional view schematically showing one embodiment of a wafer prober according to the present invention, and FIG.
FIG. 15 is a sectional view taken along line AA of the wafer prober shown in FIG. 14. In the wafer prober 601, the grooves 6 having a concentric circular shape in plan view are formed on the surface of the ceramic substrate 63 in a circular shape in plan view.
7 are formed, and a plurality of suction holes 68 for sucking the silicon wafer are provided in a part of the groove 67, and most of the ceramic substrate 63 including the groove 67 is connected to an electrode of the silicon wafer. Are formed in a circular shape.

On the other hand, on the bottom surface of the ceramic substrate 63, a heating element 69 having a concentric circular shape in plan view as shown in FIG. 3 is provided in order to control the temperature of the silicon wafer. Are connected and fixed to external terminal pins (not shown). The ceramic substrate 6
Inside 3, a guard electrode 65 and a ground electrode 66 (see FIG. 7) having a lattice shape in plan view are provided for removing stray capacitors and noise. Guard electrode 65
The material of the ground electrode 66 may be the same as that of the electrostatic electrode.

The thickness of the chuck top conductor layer 62 is
1 to 20 μm is desirable. If the thickness is less than 1 μm, the resistance value becomes too high to function as an electrode, while if it exceeds 20 μm, the conductor tends to be peeled off due to the stress of the conductor.

As the chuck top conductor layer 62, for example, copper, titanium, chromium, nickel, a noble metal (gold, silver,
At least one metal selected from refractory metals such as platinum, molybdenum, and the like can be used.

In the wafer prober having such a configuration, after a silicon wafer having an integrated circuit formed thereon is mounted thereon, a probe card having tester pins is pressed against the silicon wafer, and a voltage is applied while heating and cooling. To conduct a continuity test. In the case of manufacturing a wafer prober, for example, similarly to the case of an electrostatic chuck, first, a ceramic substrate in which a resistance heating element is embedded is manufactured, and then, a groove is formed on the surface of the ceramic substrate, and then, Then, a metal layer may be formed by applying sputtering, plating, or the like to the surface portion where the groove is formed.

[0090]

The present invention will be described in more detail below. (Example 1) Manufacture of electrostatic chuck (see FIG. 1) (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama, average particle size 1.1 μm), yttria (average particle size:
0.4 μm) 4 parts by weight, acrylic resin binder (SA-545 series, Mitsui Chemicals, SA-545 series, acid value 0.5) 11.5 parts by weight, dispersant 0.5 part by weight, and alcohol composed of 1-butanol and ethanol The paste mixed with 53 parts by weight was molded by a doctor blade method to obtain a green sheet having a thickness of 0.47 mm.

(2) Next, the green sheet is heated to 80 ° C.
After drying for 5 hours, punch 1.8m in diameter
A portion serving as a through hole for inserting a lifter pin of a semiconductor wafer having a length of 3.0 mm or 5.0 mm and a portion serving as a through hole for connecting to an external terminal were provided.

(3) 100 parts by weight of tungsten carbide particles having an average particle diameter of 1 μm, acrylic binder 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 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. This conductor paste A was printed on a green sheet by screen printing to form a conductor paste layer. The printing pattern was a concentric pattern. Further, a conductor paste layer composed of an electrostatic electrode pattern having the shape shown in FIG. 2 was formed on another green sheet.

Further, the conductive paste B was filled in through holes for through holes for connecting external terminals. On the green sheet 50 after the above processing, 34 green sheets 50 ′ on which no tungsten paste is printed are laminated on the upper side (heating surface) and 13 green sheets 50 ′ are laminated on the lower side, and a conductive paste composed of an electrostatic electrode pattern is formed thereon. The green sheet 50 on which the layers are printed is laminated, and two green sheets 50 ′ on which the tungsten paste is not printed are further laminated thereon, and these are pressed at 130 ° C. under a pressure of 80 kg / cm ² to form a laminate. It was formed (FIG. 7A).

(4) Next, the obtained laminate was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. under a pressure of 5-1.
Hot pressing was performed at 50 kg / cm ² for 0.5 to 3 hours (see Table 1 for details) to obtain an aluminum nitride plate having a thickness of 3 mm. This is cut out into a disk shape of 230 mm, and a resistance heating element 5 of 6 μm thickness and 10 mm width and a
(FIG. 7 (b)).

(5) Next, the plate obtained in (4) is
After polishing with a diamond grindstone, a mask is placed and Si
A bottomed hole (diameter: 1.2 mm, depth: 2.0 mm) for a thermocouple was provided on the surface by blasting treatment with C or the like.

(6) Further, the portions where the through holes are formed are cut out to form blind holes 13 and 14 (FIG. 7).
(C)) External holes 6 and 18 made of Kovar were connected to the blind holes 13 and 14 by heating and reflowing at 700 ° C. using gold solder made of Ni—Au (FIG. 7D). In addition,
The connection of the external terminals is preferably a structure in which a tungsten support is supported at three points. This is because connection reliability can be ensured.

(7) 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 was completed. The porosity, porosity, withstand voltage, breakdown toughness value, adsorption force, temperature-rise characteristics, and the like of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element manufactured in this manner.
The amount of warpage and volume resistivity were measured by the following methods. The results are shown in Tables 1 and 2 below. When the thermal conductivity was measured by the laser flash method,
The value of W / mk was shown.

Comparative Example 1 First, 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size: 1.1 μm)
4 parts by weight of yttria (average particle size: 0.4 μm), 0.1 parts by weight of crystalline graphite (GC-102 manufactured by Ibiden), 0.5 parts by weight of dispersant, and 53 parts by weight of alcohol composed of 1-butanol and ethanol The paste obtained by mixing the parts was molded by a doctor blade method to obtain a green sheet having a thickness of 0.47 mm. Thereafter, an electrostatic chuck was manufactured in the same manner as in Example 1. However, the pressing time and pressure during molding are as shown in Table 1. The porosity, porosity, withstand voltage, fracture toughness value, adsorption force, temperature rise characteristic, amount of warpage, and volume resistivity of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element thus manufactured are as follows. It was measured by the method. The results are shown in Table 1 below.
And 2.

Comparative Example 2 An electrostatic chuck was manufactured in the same manner as in Example 1 except that no pressure was applied during sintering. The porosity, porosity, withstand voltage, fracture toughness value, adsorption force, temperature rise characteristic, amount of warpage, and volume resistivity of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element thus manufactured are as follows. It was measured by the method. The results are shown in Table 1 below.
And 2.

Example 2 Production of Electrostatic Chuck (See FIG. 4) (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1 μm), yttria (average particle size:
0.4 μm) 4 parts by weight, acrylic resin binder (trade name KC-600 series, manufactured by Kyoeisha, acid value 17)
Molding by a doctor blade method using a paste obtained by mixing 5 parts by weight, 0.5 part by weight of a dispersant, 0 or 3% by weight of BN (details in Table 3), and 53 parts by weight of alcohol composed of 1-butanol and ethanol To a thickness of 0.
A 47 mm green sheet was obtained.

(2) Next, the green sheet is heated to 80 ° C.
After drying for 5 hours, punch 1.8m in diameter
A portion serving as a through hole for inserting a lifter pin of a semiconductor wafer having a length of 3.0 mm or 5.0 mm and a portion serving as a through hole for connecting to an external terminal were provided.

(3) 100 parts by weight of tungsten carbide particles having an average particle diameter of 1 μm, acrylic binder 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 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. This conductor paste A was printed on a green sheet by screen printing to form a conductor paste layer composed of an electrostatic electrode pattern having the shape shown in FIG.

Further, a conductive paste B was filled in a through hole for a through hole for connecting an external terminal. On the green sheet 50 after the above processing, one green sheet 50 'on which no tungsten paste is printed is further laminated on the upper side (heating surface) and 48 green sheets on the lower side.
The laminate was formed by pressure bonding at 0 ° C. and a pressure of 80 kg / cm ² .

(4) Next, the obtained laminate was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. under a pressure of 5-1.
Hot pressing was performed at 50 kg / cm ² (details in Table 3) for 3 hours to obtain a 3 mm-thick aluminum nitride plate. This is cut out into a 230 mm disc, and the thickness is 15 μm
Of aluminum nitride having the chuck positive electrode electrostatic layer 2 and the chuck negative electrode electrostatic layer 3 described above.

(5) A mask was placed on the bottom surface of the plate obtained in (4) above, and a concave portion (not shown) for a thermocouple was provided on the surface by blasting with SiC or the like.

(6) Next, the resistance heating element 15 was printed on the surface (bottom surface) facing the wafer mounting surface. For printing, a conductor paste was used. As the conductive paste, Solvest PS603D manufactured by Tokuri Chemical Laboratory, which is used for forming through holes in a printed wiring board, was used. This conductor paste
It is a silver / lead paste, and 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) is 7 to 100 parts by weight of silver. 0.5 parts by weight. The silver had a scaly shape with an average particle size of 4.5 μm.

(7) The plate-like body on which the conductor paste is printed is
By heating and baking at 80 ° C., silver and lead in the conductor paste were sintered and baked on a ceramic substrate. Further, the plate was immersed in an electroless nickel plating bath comprising 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, and the surface of the silver sintered body 15 was immersed. A nickel layer 150 having a thickness of 1 μm and a boron content of 1% by weight or less was deposited.
Thereafter, the plate was subjected to annealing at 120 ° C. for 3 hours. A resistance heating element made of a silver sintered body has a thickness of 5 mm.
μm, a width of 2.4 mm, and a sheet resistivity of 7.7 mΩ /
It was □.

(8) Next, a blind hole for exposing the through hole 16 was formed in the ceramic substrate. N
Using a gold solder made of an i-Au alloy (81.5% by weight of Au, 18.4% by weight of Ni, 0.1% by weight of impurities),
After heating and reflow at 0 ° C., external terminal pins made of Kovar were connected. Also, external terminal pins made of Kovar were formed on the resistance heating element via solder (tin 9 / lead 1).

(9) Next, a plurality of thermocouples for temperature control were buried in the concave portions to obtain the electrostatic chuck 201. The porosity, porosity, withstand voltage, fracture toughness value, adsorption force, temperature rise characteristic, amount of warpage, and volume resistivity of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element thus manufactured are as follows. It was measured by the method. The results are shown in Tables 3 and 4 below.

(10) Next, this electrostatic chuck 201 is mounted on a stainless steel supporting container 41 having a sectional shape shown in FIG.
Was inserted through a heat insulating material 45 made of ceramic fiber (trade name: IBIWOOL, manufactured by IBIDEN). This support container 41 has a refrigerant outlet 42 for cooling gas,
The temperature of the electrostatic chuck 201 can be adjusted. The resistance heating element 15 of the electrostatic chuck 201 fitted in the support container 41 was energized to raise the temperature, and the temperature of the electrostatic chuck 201 was controlled by flowing a coolant through the support container. Temperature could be controlled.

Comparative Example 3 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size: 1.1 μm), 4 parts by weight of yttria (average particle size: 0.4 μm), crystalline graphite (GP-202, manufactured by Ibiden) 0.1) parts by weight, 0.5 parts by weight of dispersant, 3% by weight of BN (details in Table 3) and alcohol 53 composed of 1-butanol and ethanol
A green sheet having a thickness of 0.47 mm was formed by using a paste mixed with parts by weight by a doctor blade method. Thereafter, an electrostatic chuck was manufactured in the same manner as in Example 2. However, the pressure during molding is as shown in Table 1. The porosity, the pore diameter, and the porosity of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element manufactured as described above.
The withstand voltage, the fracture toughness value, the adsorption force, the temperature rising characteristic, the amount of warpage, and the volume resistivity were measured by the following methods. The results are shown in Tables 3 and 4 below.

Comparative Example 4 An electrostatic chuck was manufactured in the same manner as in Example 2 except that no pressure was applied during sintering. The porosity, porosity, withstand voltage, fracture toughness value, adsorption force, temperature rise characteristic, amount of warpage, and volume resistivity of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element thus manufactured are as follows. It was measured by the method. The results are shown in Table 3 below.
And 4.

(Embodiment 3) Electrostatic chuck 301 (FIG. 5)
(1) Two electrodes having the shape shown in FIG. 8 were formed by punching a 10 μm-thick tungsten foil. 100 parts by weight of the two electrodes and the tungsten wire were treated with aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1 μm),
With 4 parts by weight of yttria (average particle size 0.4 μm)
Alumina 1.5% by weight, acrylic resin binder (trade name KC-600 series, acid value 17 manufactured by Kyoeisha Co., Ltd.)
5 parts by weight were put in a mold, and 1890 ° C.
Hot pressing was performed at a pressure of 5 to 150 kg / cm ² (details in Table 5) for 3 hours to obtain an aluminum nitride plate having a thickness of 3 mm. This was cut into a circular shape having a diameter of 230 mm to obtain a plate-like body. At this time, the thickness of the electrostatic electrode layer was 10 μm.

(2) The steps (5) to (7) of Example 1 were performed on the plate-like body to obtain an electrostatic chuck 301. The porosity, porosity, withstand voltage, fracture toughness value, adsorption force, temperature rise characteristic, amount of warpage, and volume resistivity of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element thus manufactured are as follows. It was measured by the method. The results are shown in Tables 5 and 6 below.

(Comparative Example 5) Two electrodes and a tungsten wire were coated with aluminum nitride powder (manufactured by Tokuyama, average particle size 1.1).
μm) 100 parts by weight, yttria (average particle size 0.4 μm)
m) Along with 4 parts by weight, 1.5 parts by weight of alumina and 0.1 parts by weight of crystalline graphite (GP-102, manufactured by Ibiden) were placed in a mold and placed in a nitrogen gas at 1890 ° C. under a pressure of 1
Hot pressing was performed at 50 kgf / cm ² (details in Table 5) for 3 hours to obtain an aluminum nitride plate having a thickness of 3 mm. This was cut into a circular shape having a diameter of 230 mm to obtain a plate-like body.
Thereafter, an electrostatic chuck was manufactured in the same manner as in Example 1. However, the pressure during molding is as shown in Table 1.
The porosity, the pore diameter, the withstand voltage, and the porosity of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element manufactured as described above are described.
Fracture toughness, adsorption power, temperature rise characteristics, warpage, and volume resistivity were measured by the following methods. The results are shown in Tables 5 and 6 below.

Comparative Example 6 An electrostatic chuck was manufactured in the same manner as in Example 1 except that the pressing conditions during sintering were set as shown in Table 5. The porosity, porosity, withstand voltage, breakdown toughness value, adsorption force, temperature-rise characteristics, and the like of the ceramic dielectric film 4 of the electrostatic chuck having the resistance heating element manufactured in this manner.
The amount of warpage and volume resistivity were measured by the following methods. The results are shown in Tables 5 and 6 below.

(Example 4 and Comparative Example 7) Production of Electrostatic Chuck 401 (FIG. 6) Steps (1) to (5) of Example 2 (First-stage conditions in Table 3)
After that, nickel was further sprayed on the bottom surface, and thereafter, a lead / tellurium-based Peltier element was joined to obtain an electrostatic chuck 401. The thus manufactured electrostatic chuck was excellent in temperature-fall characteristics, and was cooled from 450 ° C. to 100 ° C. in 3 minutes when cooled by a Peltier device. In addition, the electrode has excellent concealing properties.

Example 5 100 parts by weight of silicon carbide powder (manufactured by Yakushima Electric Works, average particle size: 1.1 μm), acrylic binder (manufactured by Mitsui Chemicals, SA-545 series)
Using a paste obtained by mixing 5 parts by weight, 0.5 part by weight of a dispersant, and 53 parts by weight of alcohol composed of 1-butanol and ethanol, a green sheet having a thickness of 0.5 mm was obtained by performing molding by a doctor blade method. Further, an electrostatic chuck was manufactured in the same manner as in Example 1, except that a glass paste was applied to a portion in contact with the conductor paste and laminated. The withstand voltage is determined by the wafer mounting surface and conductor (electrostatic electrode)
Was measured between The maximum pore size was 20 μm.

Comparative Example 8 100 parts by weight of silicon carbide powder (manufactured by Yakushima Denko Co., average particle size 1.1 μm), 11.5 parts by weight of a phenol resin (decomposed and modified into crystalline graphite), 0.1 part by weight of dispersant. Using a paste obtained by mixing 5 parts by weight and 53 parts by weight of alcohol composed of 1-butanol and ethanol, molding was performed by a doctor blade method,
An electrostatic chuck was manufactured in the same manner as in Example 1, except that a green sheet having a thickness of 0.5 mm was obtained. The maximum pore size was 22 μm. When the withstand voltage at 450 ° C. of the electrostatic chuck obtained in Example 5 and the electrostatic chuck obtained in Comparative Example 8 was measured, it was 1.0 kV / m in Example 5, whereas In Example 8, it was 0.01 kV / m.

(Example 6 and Comparative Example 9) A concave portion was formed on the surface of the electrostatic chuck of Example 1 and Comparative Example 1 by drilling, and a support pin made of alumina was formed in this concave portion.
The distance between the wafer and the heating surface was set to 100 μm. Then, without applying a voltage to the electrostatic electrode, only the heating element was energized and heated, and the temperature was raised to 400 ° C. When the amount of warpage was 0 or 1 μm, the difference in wafer surface temperature was 3 ° C., but the amount of warpage was 8 ° C.
In the case of μm, the surface temperature difference was 10 ° C., and the uniformity of the surface temperature was poor.

(Test Example) In the same manner as in Comparative Example 1,
Aluminum nitride was sintered at room temperature to produce an electrostatic chuck having a thickness of 30 mm. Also, in the same manner as in Comparative Example 1, aluminum nitride was sintered at room temperature to manufacture an electrostatic chuck having a diameter of 150 mm. Both electrostatic chucks are 45
The warpage after heating to 0 ° C. was 1 μm or less. That is, the ceramic substrate having a thickness of more than 25 mm and a diameter of less than 200 mm did not cause the warpage problem. Also, when an electrostatic chuck having no through hole was manufactured, the amount of warpage after heating to 450 ° C. was 1 μm or less. Thus, the present invention has a diameter of 200 mm or more,
It is considered that a ceramic substrate having a thickness of 25 mm or less and having a through hole is particularly effective.

[0122]Evaluation method  (1) Laser Raman spectroscopy Ceramic dielectric of the electrostatic chuck obtained in Examples 1 and 2
Laser Raman spectroscopy of the body film under the following measurement conditions
Analysis was carried out. The results are shown in FIGS.
(Example 2) and 16 (Comparative Examples 1 and 2). Laser power: 200 mW, excitation wavelength: 514.5 n
m, slit width: 1000 μm, gate time:
1, repeat time: 4, temperature: 25.0 ° C

(2) Measurement of Porosity of Ceramic Dielectric Film The ceramic dielectric film was cut out and the porosity was measured by the Archimedes method. Specifically, the cut sample is crushed into powder, poured into an organic solvent, the volume is measured, the true specific gravity is measured from the weight of the powder measured in advance, and the porosity is calculated from this and the apparent specific gravity. did. (3) Measurement of Pore Diameter of Ceramic Dielectric Film The electrostatic chuck was cut at several locations in the longitudinal direction, and the length of pores at the cut portions was measured with a microscope. When the vertical and horizontal lengths were different, the maximum value was taken.

(4) Evaluation of Withstand Voltage of Ceramic Dielectric Film For the electrostatic chucks manufactured in Examples and Comparative Examples 1 to 4, a metal electrode was placed on the electrostatic chuck, and an electrostatic electrode layer and an electrode were formed. During this period, a voltage was applied, and the voltage at which dielectric breakdown occurred was measured. (5) Fracture toughness value An indenter was pressed into the surface with a Vickers hardness tester (MVK-D manufactured by Akashi Seisakusho), the length of the generated crack was measured, and this was substituted into the following formula. Fracture toughness = 0.
026 × E ^1/2 × 0.5 × P ^1/2 × a × C ^-3/2 E is Young's modulus (3.18 × 10 ¹¹ Pa), P is indentation load (9
8N), a is half of the diagonal length of the indentation (m), and C is half of the average crack length (m).

(6) Adsorption force Load cell (Autograph AGS-5 manufactured by Shimadzu Corporation)
OA). (7) Temperature rise characteristics The time required to raise the temperature to 450 ° C. was measured. (8) Warp amount After raising the temperature to 450 ° C. and applying a load of 150 kgcm ² , the temperature was cooled to 25 ° C., and the warp amount (difference between before and after the test) was measured using a shape measuring instrument (Kyocera Nanoway). .

(9) Volume resistivity: The sintered body was cut into a shape having a diameter of 10 mm and a thickness of 3 mm by cutting to form three terminals (main electrode, counter electrode, guard electrode).
After applying a DC voltage and reading the current (I) flowing through the digital electrometer after charging for 1 minute, determine the resistance (R) of the sample, and determine the volume resistivity (ρ) from the resistance (R) and the dimensions of the sample as follows. Was calculated by the calculation formula (1).

[0127]

(Equation 1)

In the above formula (1), t is the thickness of the sample. S is given by the following equations (2) and (3).

[0129]

(Equation 2)

[0130]

(Equation 3)

It should be noted that the above equations (2) and (3)
And D₁ Is the diameter of the main electrode, D_Two Is the inner diameter of the guard electrode
(Diameter), and in this embodiment, D₁ = 1.45
cm, D _Two = 1.60 cm.

(10) Carbon Amount The carbon amount in the sintered body was measured by crushing the sintered body and heating it at 500 to 800 ° C. to collect the generated CO _x gas. (11) Oxygen content A sample sintered under the same conditions as the sintered body according to the example was pulverized in a tungsten mortar, 0.01 g of the sample was collected, and heated at a sample heating temperature of 2200 ° C. and a heating time of 30 seconds. oxygen·
The measurement was performed with a nitrogen simultaneous analyzer (TC-136 manufactured by LECO).

[0133]

[Table 1]

[0134]

[Table 2]

[0135]

[Table 3]

[0136]

[Table 4]

[0137]

[Table 5]

[0138]

[Table 6]

From the above table, it is clear that the electrostatic chuck according to the present invention has a withstand voltage at a high temperature of 12 to 20 kV / mm at normal temperature and 1 to 10 kV / m at 450 ° C. even if there are pores.
m and excellent. In addition, the volume resistivity at high temperatures is also high.
× 10 ⁸ Ω · cm or more can be secured, the temperature rise characteristics are excellent, and the amount of warpage at high temperatures can be extremely reduced. Further, when pores are present, 3.5 MPam
High fracture toughness of ^1/2 or more can be secured. Further, by setting the pore diameter of the maximum pore to 10 μm or less, the amount of warpage at a high temperature can be reduced to about 2 μm or less. Further, when no pores are provided, the withstand voltage becomes extremely high, and the warpage at a high temperature can be almost completely eliminated.

Embodiment 7 A wafer prober 601 (FIG. 1)
(1) 1000 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1 μm), 40 parts by weight of yttria (average particle size 0.4 μm), 5 parts by weight of BN, acrylic resin binder ( Mitsui Chemicals SA-545 Series
A mixed composition obtained by mixing 115 parts by weight of an acid value 0.5) and 530 parts by weight of an alcohol composed of 1-butanol and ethanol was molded by a doctor blade method to obtain a green sheet having a thickness of 0.47 mm. Obtained.

(2) Next, the green sheet was heated to 80 ° C.
After drying for 5 hours, a through hole for a through hole for connecting the heating element and the external terminal pin was provided by punching.

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

Next, a grid-shaped printed body for a guard electrode and a printed body for a ground electrode were printed on the green sheet by screen printing using the conductive paste A. In addition, the conductive paste B was filled in through holes for through holes for connection with terminal pins.

Further, 50 printed green sheets and 50 unprinted green sheets were laminated and 1
A laminate was produced by integrating at 30 ° C. and a pressure of 80 kg / cm ² .

(4) Next, this laminate is placed in nitrogen gas for 6 hours.
Degreasing at 00 ° C for 5 hours, 1890 ° C, pressure 150kg /
Hot pressing was performed for 3 hours at ² cm ² to obtain a 3 mm-thick aluminum nitride plate. The obtained plate-like body was prepared with a diameter of 300
It was cut out into a circular shape of mm to obtain a ceramic plate. The size of the through hole 16 was 0.2 mm in diameter and 0.2 mm in depth.

The guard electrode 65 and the ground electrode 66
Is 10 μm, the formation position of the guard electrode 65 is 1 mm from the wafer mounting surface, and the formation position of the ground electrode 66 is
It was 1.2 mm from the wafer mounting surface. The conductor non-forming region 66a of the guard electrode 65 and the ground electrode 66
Of one side was 0.5 mm.

(5) The plate obtained in the above (4) is polished with a diamond grindstone, a mask is placed on the plate, and a blast process using SiC or the like is performed on the surface to form a concave portion for a thermocouple and a wafer suction device. Groove 47 (width 0.5 mm, depth 0.5 mm)
Was provided.

(6) Further, a layer for forming the heating element 69 was printed on the surface facing the wafer mounting surface. For printing, a conductor paste was used. As the conductive paste, Solvest PS603D manufactured by Tokuri Chemical Laboratory, which is used for forming through holes in a printed wiring board, was used. This conductor paste is a silver / lead paste, and 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) is converted to silver 10
It contained 7.5 parts by weight with respect to 0 parts by weight. The silver had a scaly shape with an average particle size of 4.5 μm.

(7) The heater plate on which the conductor paste was printed was heated and fired at 780 ° C. to sinter silver and lead in the conductor paste and to sinter the ceramic substrate 63. Further, nickel sulfate 30 g / l, boric acid 30 g / l, ammonium chloride 30 g / l and Rochelle salt 60 g / l
The heater plate is immersed in an electroless nickel plating bath composed of an aqueous solution containing, and a nickel layer having a thickness of 1 μm and a boron content of 1% by weight or less (not shown) is formed on the surface of the silver sintered body 69.
Was precipitated. Thereafter, the heater plate was annealed at 120 ° C. for 3 hours. The heating element made of a silver sintered body had a thickness of 5 μm, a width of 2.4 mm, and a sheet resistivity of 7.7 mΩ / □.

(8) A titanium layer, a molybdenum layer, and a nickel layer were sequentially formed on the surface on which the grooves 47 were formed by sputtering. As a device for sputtering, SV-4540 manufactured by Japan Vacuum Engineering Co., Ltd. was used. The sputtering conditions were as follows: atmospheric pressure 0.6 Pa, temperature 100 ° C.,
The power was 200 W, and the sputtering time was adjusted for each metal within a range of 30 seconds to 1 minute. The thickness of the obtained film was determined from the image of the X-ray fluorescence spectrometer to be 0.3 μm for the titanium layer, 2 μm for the molybdenum layer, and 1 μm for the nickel layer.
m.

(9) Nickel sulfate 30 g / l, boric acid 3
The ceramic plate obtained in the above (8) is immersed in an electroless nickel plating bath comprising an aqueous solution containing 0 g / l, ammonium chloride 30 g / l and Rochelle salt 60 g / l, and the surface of the metal layer formed by sputtering. Then, a nickel layer having a thickness of 7 μm and a boron content of 1% by weight or less was deposited and annealed at 120 ° C. for 3 hours. The surface of the heating element does not pass current and is not covered with electrolytic nickel plating.

Further, 2 g of potassium potassium cyanide /
l, 75 g / l ammonium chloride, 50 g / l sodium citrate and 10 g / l sodium hypophosphite in an electroless gold plating solution at 93 ° C. for 1 minute,
A gold plating layer having a thickness of 1 μm was formed on the nickel plating layer.

(10) An air suction hole 48 that passes through the groove 67 to the back surface is formed by drilling, and a blind hole (not shown) for exposing the through hole 660 is provided.
A Ni-Au alloy (81.5% by weight of Au, Ni
An external terminal pin made of Kovar was connected by heating and reflowing at 970 ° C. using a brazing filler metal consisting of 18.4% by weight and 0.1% by weight of impurities. In addition, solder (tin 90)
(Weight% / lead 10 weight%) to form external terminal pins made of Kovar.

(11) Next, a plurality of thermocouples for temperature control were buried in the recesses to obtain a wafer prober heater 601.

The ceramic substrate has a maximum pore diameter of 2
In μm, the porosity was 1%. Although the temperature of the ceramic substrate was raised to 200 ° C., no dielectric breakdown occurred even when 200 V was applied. Further, the amount of warpage was good at 1 μm or less. Furthermore, since the ceramic substrate is black, there is an advantage that it is easy to perform a visual inspection as to whether or not the chuck top conductor layer is formed favorably by plating.

[0156]

As described above, the ceramic substrate for a semiconductor manufacturing / inspection apparatus according to the present invention can secure the concealing property and the withstand voltage even at a high temperature. Further, since the pores may be large, the fracture toughness value can be improved, and the firing conditions can be relaxed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one example of an electrostatic chuck according to the present invention.

FIG. 2 is a sectional view taken along line AA of the electrostatic chuck shown in FIG.

FIG. 3 is a sectional view taken along line BB of the electrostatic chuck shown in FIG. 1;

FIG. 4 is a sectional view schematically showing an example of the electrostatic chuck according to the present invention.

FIG. 5 is a sectional view schematically showing an example of the electrostatic chuck according to the present invention.

FIG. 6 is a cross-sectional view schematically showing one example of the electrostatic chuck according to the present invention.

FIGS. 7A to 7D are cross-sectional views schematically showing a part of the manufacturing process of the electrostatic chuck of the present invention.

FIG. 8 is a horizontal sectional view schematically showing a shape of an electrostatic electrode constituting the electrostatic chuck according to the present invention.

FIG. 9 is a horizontal sectional view schematically showing the shape of an electrostatic electrode constituting the electrostatic chuck according to the present invention.

FIG. 10 is a cross-sectional view schematically showing a state where the electrostatic chuck according to the present invention is fitted into a support container.

FIG. 11 is a laser Raman spectrum showing the result of laser Raman spectroscopic analysis of the ceramic dielectric film constituting the electrostatic chuck obtained in Example 1.

FIG. 12 is a laser Raman spectrum showing the result of laser Raman spectroscopy analysis of the ceramic dielectric film constituting the electrostatic chuck obtained in Example 2.

FIG. 13 is a cross-sectional view schematically showing a hot plate according to the present invention.

FIG. 14 is a cross-sectional view schematically showing a wafer prober according to the present invention.

FIG. 15 is a cross-sectional view schematically showing a guard electrode of the wafer prober according to the present invention.

FIG. 16 is a laser Raman spectrum showing the results of laser Raman spectroscopy analysis of the ceramic dielectric films constituting the electrostatic chucks obtained in Comparative Examples 1 and 2.

[Explanation of symbols]

 101, 201, 301, 401 Electrostatic chuck 1 Ceramic substrate 2, 22, 32a, 32b Chuck positive electrode layer 3, 23, 33a, 33b Chuck negative electrode layer 2a, 3a Semicircular portion 2b, 3b Comb portion Reference Signs List 4 ceramic dielectric film 5 resistance heating element 6, 18 external terminal pin 7 metal wire 8 Peltier element 9 silicon wafer 11 bottomed hole 12 through hole 13, 14 blind hole 15 resistance heating element 150 metal layer 16, 17 through hole 41 support Container 42 Refrigerant outlet 43 Inlet 44 Refrigerant inlet 45 Insulation material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01L 21/66 H05B 3/20 393 H05B 3/10 C04B 35/56 101H 3/16 101N 3/20 393 101Y 35/58 104H 104R 104Y

Claims (6)

[Claims] 1. A conductive material is provided on the surface or inside of a ceramic substrate.
A ceramic substrate on which a body is formed;
Mic substrate is 1550 cm in Raman spectrum^-1And
1333cm ^-1Contains carbon with a peak near
A ceramic having a maximum porosity of the ceramic.
Semiconductor having a pore diameter of 50 μm or less
Ceramic substrate for fabrication and inspection equipment. 2. The amount of carbon is 5 to 5000 ppm.
The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 1, wherein 3. The ceramic according to claim 1, wherein the ceramic is a nitride ceramic,
3. The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 1, wherein the ceramic substrate is at least one selected from an oxide ceramic and a carbide ceramic. 4. The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 1, wherein the diameter is 200 mm or more and the thickness is 25 mm or less. 5. The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 1, wherein said ceramic substrate has a plurality of through holes for lifter pins. 6. The method according to claim 1, which is used at 100 to 700 ° C.
6. The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to any one of items 5 to 5.