JP2001307969A - Ceramic substrate for semiconductor process and for testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic substrate for realizing a practically uniform distribution of temperatures on a face thereof, on which a semiconductor wafer is treated. SOLUTION: The ceramic substrate has a conductive body in the surface or the inside thereof. The ceramic substrate contains oxygen has a shape like a disk with a diameter more than 250 mm and a thickness of 25 mm or below.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in a semiconductor manufacturing and inspection apparatus including an etching apparatus and a chemical vapor deposition apparatus, a heater using a metal base material such as stainless steel or an aluminum alloy, a wafer prober, and the like have been used. Has been used. However, the metal heater has a problem that the temperature control characteristic is poor, and the thickness is large, so that the heater is heavy and bulky, and the corrosion resistance to corrosive gas is also poor.

In order to solve such a problem, heaters using ceramics such as aluminum nitride instead of metal heaters have been developed. Such a ceramic heater has an advantage in that the ceramic substrate itself has a high rigidity, and therefore, it is possible to prevent the substrate from being warped or the like without making the thickness too large. Particularly suitable for chucks.

[0004] In recent years, as semiconductor wafers have become larger and their diameters have become larger, electrostatic chucks and the like used in the manufacture and inspection of such semiconductor wafers have a large size. The diameter must be increased, for example, as disclosed in JP-A-11-74064.
Japanese Patent Application Publication No. JP-A-2005-64139 discloses a hot plate made of aluminum nitride ceramic having a diameter of 300 mm and a thickness of 17 mm.

[0005]

As described above, when the size of the electrostatic chuck or the like is increased, there is a problem that the temperature rising characteristics and the uniform temperature of the ceramic substrate required for manufacturing a semiconductor element or the like are deteriorated. Was.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have a diameter of 250 m.
In addition to finding out that the reason for the decrease in the temperature rise characteristics and soaking properties of large ceramic substrates exceeding m is that the heat capacity of the ceramic substrates increases, the sintering properties of the ceramic substrates can be improved by incorporating oxygen into the ceramic substrates. It has been found that the temperature rise characteristic and the soaking property can be improved by reducing the heat capacity itself by improving the heat conduction barrier between the ceramic particles and reducing the heat capacity itself by adjusting the thickness to 25 mm or less. In the case of a large-sized ceramic substrate having a diameter exceeding 250 mm, the thickness is set to 25 mm.
If the thickness is adjusted to within mm, warpage tends to occur at high temperatures, but the conductor is formed at a position 60% in the thickness direction from the side opposite to the wafer processing surface of the ceramic substrate, and the ceramic itself is nitrided containing oxygen. It has been found that warping can be almost completely eliminated by using a ceramic or oxide ceramic, and the present invention has been completed.

Further, when the diameter of the disk-shaped ceramic substrate is 250 mm or more, the thickness of the ceramic substrate is adjusted to 25 mm or less to reduce the heat capacity of the ceramic substrate. Is provided inside the ceramic substrate, the distance from the heating surface is shortened accordingly, and a temperature distribution similar to the pattern of the resistance heating element is generated. Therefore, by providing a conductor such as a resistance heating element on the back side of the ceramic substrate, the distance between the heating surface and the resistance heating element can be ensured, and it has been found that the temperature rise characteristics and the soaking property can be improved. The present invention has been completed. Further, when the thickness of the ceramic substrate is adjusted to 25 mm or less, warpage tends to occur at high temperatures, but the present invention can also prevent such warpage. Incidentally, Japanese Patent Application Laid-Open No. 11-740
No. 64 discloses a hot plate made of an aluminum nitride ceramic having a diameter of 300 mm and a thickness of 17 mm, but also describes the problem of warpage at high temperatures.
Neither is suggested, and the above publication does not hinder the novelty and inventive step of the present invention.

According to a first aspect of the present invention, there is provided a ceramic substrate having a conductor on the surface or inside of the ceramic substrate, wherein the ceramic substrate contains oxygen, and the ceramic substrate has a disk shape and a diameter of 250 mm. Semiconductor manufacturing characterized in that its thickness is not more than 25 mm
It is a ceramic substrate for an inspection device. A second aspect of the present invention is a ceramic substrate having a conductor on a surface of the ceramic substrate, wherein the ceramic substrate has a disk shape, a diameter of which exceeds 250 mm, and a thickness of which is 25 mm or less. Is a ceramic substrate for a semiconductor manufacturing / inspection apparatus. In the first and second aspects of the present invention, the formation position of the conductor is different, and whether or not it contains oxygen is different, but the other components are the same. The contents will be described together with the invention.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A ceramic substrate for a semiconductor manufacturing / inspection apparatus according to the present invention is a ceramic substrate having a conductor inside or on the surface of the ceramic substrate. Over 250mm,
The thickness is not more than 25 mm. The ceramic substrate preferably contains oxygen or is an oxide ceramic.

In the ceramic substrate of the present invention, the diameter of the ceramic substrate is set to be larger than 250 mm, while the thickness is adjusted to 25 mm or less to suppress the increase in the overall weight. Can be prevented from becoming too large, and a ceramic substrate having a uniform temperature distribution that does not hinder processing of a semiconductor wafer or the like can be obtained.

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. I will. The thickness of the ceramic substrate is more preferably 10 mm or less, particularly preferably 5 mm or less. When the thickness exceeds 10 mm, the heat capacity at 200 ° C. or higher becomes large, and the temperature controllability and the temperature uniformity of the surface on which the semiconductor wafer is mounted are likely to be reduced. The ceramic substrate,
Used in the temperature range of 100 to 700 ° C. In a temperature range of 100 ° C. or higher, the Young's modulus of the ceramic is reduced and warpage is likely to occur, and the effect of the present invention is beneficial.
The ceramic substrate preferably has a plurality of through holes into which lifter pins of a semiconductor wafer are inserted. This is because, when there is a through-hole, the Young's modulus decreases at a temperature of 100 ° C. or higher, distortion during processing is released, and warpage easily occurs, and the effect of the present invention becomes remarkable. The diameter of the through hole is
0.5 mm to 30 mm is desirable. In addition, in the ceramic substrate of the present invention, in addition to placing the semiconductor wafer in contact with one surface of the ceramic substrate, the semiconductor wafer is supported by lifter pins, support pins, and the like, and a certain distance is provided between the semiconductor wafer and the ceramic substrate. In some cases, it is held and held (see FIG. 9). Such a mounting / holding surface of a semiconductor wafer is hereinafter referred to as a wafer processing surface. In the case of supporting with a support pin, for example, a concave portion is formed in the ceramic substrate, and a support pin is provided in the concave portion so that the tip slightly projects from the wafer processing surface, and the semiconductor wafer is supported by the support pin. When heating while keeping the distance between the ceramic substrate and the semiconductor wafer constant, the separation distance is as follows:
50 to 5000 μm is desirable. When heating while keeping the distance between the ceramic substrate and the semiconductor wafer constant, the semiconductor wafer cannot be heated uniformly unless the distance between the semiconductor wafer and the holding surface of the ceramic substrate is constant. Therefore, it is necessary to reduce the amount of warpage of the ceramic substrate, and the present invention works particularly advantageously. In the present invention,
The amount of warpage is desirably less than 70 μm in the range of 100 to 700 ° C. If the thickness exceeds 70 μm, the distance between the processing surface (heating surface) of the ceramic substrate and the semiconductor wafer becomes uneven, and uniform heating of the semiconductor wafer cannot be performed.

The reason why the diameter of the ceramic substrate exceeds 250 mm is that the diameter of the semiconductor wafer is mainly 10 inches or more, and the size of the ceramic substrate is also required. The ceramic substrate is 12
Desirably, it is not less than inches (300 mm). This is because it will become the mainstream of next-generation semiconductor wafers. If the diameter of the ceramic substrate exceeds 250 mm, warping is likely to occur due to its own weight or the like at a high temperature. Such a warp is remarkable in a ceramic having a thickness of 25 mm or less. In the present invention, such a warp can be prevented by providing a conductor in a specific region of the ceramic in which the warp at such a high temperature easily occurs.

Preferably, the conductor is provided in a region from the side opposite to the wafer processing surface of the ceramic substrate to a position 60% in the thickness direction or on the side opposite to the above. Warpage is
It is generated by its own weight or, in the case of a ceramic substrate for a wafer prober (hereinafter, referred to as a wafer prober), by the pressure of a probe. For this reason, when warping occurs, a pulling force acts on the side opposite to the wafer processing surface. However, in the present invention, it is possible to resist this pulling force by providing a conductor and prevent warpage. can do. Examples of the conductor include a conductive ceramic, a metal foil, a sintered metal, and a metal wire. Metals generally have a low Young's modulus even at high temperatures.
The presence of a metal sintered body, a metal wire, etc., can prevent a decrease in the overall Young's modulus, and the conductive ceramic also has a bonding structure and a crystal structure similar to that of a metal because it is conductive. As a result, the Young's modulus at high temperatures is not easily reduced, and warpage of the ceramic substrate at high temperatures can be prevented.

When the conductor functions as a resistance heating element, it is desirable to provide the ceramic substrate in a region from the opposite side of the wafer processing surface to a position 50% in the thickness direction or on the opposite side. This is because, when heat is transferred from the heating element to the wafer processing surface through the inside of the ceramic substrate, the heat is diffused in the ceramic substrate to equalize the temperature, and the distance between the wafer processing surface and the heating element is large. This is because it is easier to make the surface temperature of the wafer processing surface uniform.

Further, in the ceramic substrate for a semiconductor device of the present invention, it is desirable to use a ceramic substrate having a Young's modulus of 280 GPa or more in a temperature range of 25 to 800 ° C. If the Young's modulus is less than 280 GPa, the rigidity is too low, so that it is difficult to reduce the amount of warpage during heating, and the warp may damage the semiconductor wafer.

In the present invention, it is desirable that no pores exist or, if there are pores, the maximum pore diameter is 50 μm or less. When no pores are present, the withstand voltage at high temperatures is particularly high, and when pores are present, the fracture toughness value is high. Or either the design for this is the vary required characteristics. It is not clear why the fracture toughness value increases due to the presence of pores,
It is presumed that crack growth is stopped by the stomata.

In the present invention, the maximum pore size is 50 μm.
It is desirable that: Maximum pore size of 50μ
If it exceeds m, the withstand voltage characteristics at high temperatures, especially at 200 ° C. or higher, cannot be secured. The maximum pore size is 10
More preferably, it is not more than μm. This is because the amount of warpage at 200 ° C. or higher is reduced. The porosity and pore diameter of the maximum porosity are determined by the pressing time, pressure, temperature, SiC and B
Adjust with additives such as N. Since SiC and BN hinder sintering, pores can be introduced.

The measurement of the pore diameter of the maximum pore is performed by preparing five samples, polishing the surface of the sample to a mirror surface, and photographing the surface at 10 places with an electron microscope at a magnification of 2000 to 5000 times. Then select the largest pore size in the photograph taken,
The average of 50 shots is defined as the maximum pore diameter. The nitride ceramic substrate desirably contains 0.05 to 10% by weight of oxygen. If the amount is less than 0.05% by weight, the withstand voltage cannot be secured, and the warpage at a high temperature cannot be prevented. If the amount exceeds 10% by weight, the withstand voltage characteristics of the oxide at a high temperature deteriorate. This is because the withstand voltage is also lowered due to the above, and the oxygen content is 10% by weight.
If the temperature exceeds the above, the thermal conductivity is lowered and the temperature rise / fall characteristics are deteriorated. In particular, 0.1 to 5% by weight is optimal.

Oxygen can be introduced by heating the raw material in air or oxygen, or by adding a sintering aid. Also, oxygen-containing ceramics (oxygen-containing nitride ceramics, oxygen-containing carbide ceramics, and oxide ceramics) hardly warp at high temperatures. This is because the Young's modulus at a high temperature does not easily decrease. 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 .

The ceramic material constituting the ceramic substrate of the present invention is not particularly limited, and examples thereof include a nitride ceramic, a carbide ceramic, and an oxide ceramic.

Examples of the nitride ceramic include metal nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, and titanium nitride. Further, as the carbide ceramic, metal carbide ceramic,
For example, silicon carbide, zirconium carbide, titanium carbide,
Examples include tantalum carbide and tansten carbide.

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

Among these ceramics, nitride ceramics and oxide ceramics are preferred. This is because warpage hardly occurs at high temperatures. Also, among nitride ceramics, aluminum nitride is most preferred. Thermal conductivity 18
This is because it is as high as 0 W / m · K.

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 ₃ is preferred. Also, alumina may be used. The content of these is desirably 0.1 to 20% by weight.

According to the present invention, 50 to 5
Desirably, it contains 000 ppm of carbon. By containing carbon, the ceramic substrate can be blackened, and radiant heat can be sufficiently used when used as a heater. The carbon may be amorphous or crystalline. When amorphous carbon is used, a decrease in volume resistivity at high temperatures can be prevented, and when crystalline carbon is used, a decrease in thermal conductivity at high temperatures can be prevented. Because. Therefore, depending on the application, both crystalline carbon and amorphous carbon may be used in combination. The carbon content is 200
~ 2000 ppm is more preferred.

When carbon is contained in the ceramic substrate, it is desirable that the carbon be contained so that its brightness becomes N6 or less as a value based on JIS Z 8721. What has this level of brightness is the amount of radiant heat,
This is because the concealing property is excellent.

Here, the lightness N is set such that the ideal black lightness is 0, the ideal white lightness is 10, and the brightness of the color is 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. The actual measurement of lightness is N0 to N1
The comparison is made with the color chart corresponding to 0. Decimal point 1 in this case
The place is 0 or 5.

The ceramic substrate of the present invention is a ceramic substrate used for an apparatus for manufacturing a semiconductor or inspecting a semiconductor. Specific examples of the apparatus include an electrostatic chuck, a wafer prober, a hot plate, and a susceptor. And the like.

FIG. 1 is a longitudinal sectional view schematically showing an example of an electrostatic chuck which is an embodiment of the ceramic substrate of the present invention, and FIG. 2 is a sectional view of the electrostatic chuck shown in FIG. FIG. 3 is a cross-sectional view of the electrostatic chuck illustrated in FIG. 1 along the line BB.

In the electrostatic chuck 101, a chuck positive electrode electrostatic layer 2 is provided inside a ceramic substrate 1 having a circular shape in plan view.
And an electrostatic electrode layer comprising a chuck negative electrode electrostatic layer 3 are embedded. A silicon wafer 9 is placed on the electrostatic chuck 101 and is grounded.

A ceramic layer formed on the electrostatic electrode layer so as to cover the electrostatic electrode layer functions as a dielectric film for adsorbing a silicon wafer. It is referred to as the film 4.

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.

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, as shown in FIG. 3, this ceramic substrate 1 supports a bottomed hole 11 for inserting a temperature measuring element and a silicon wafer 9 and raises and lowers it (lifter pin). , Not shown).
Are formed. Note that the resistance heating element 5 may be formed on the bottom surface of the ceramic substrate. Further, an RF electrode may be embedded in the ceramic substrate 1 as needed.

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. As a result, 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. . 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 has an electrostatic electrode layer and a resistance heating element, and has, for example, a configuration as shown in FIGS. Hereinafter, members constituting the electrostatic chuck that are not described in the description of the ceramic substrate plate will be described.

Ceramic dielectric film 4 on the electrostatic electrode
Is preferably made of the same material as the other parts of the ceramic substrate. This is because green sheets and the like can be manufactured in the same process, and after laminating them, a ceramic substrate can be manufactured by firing once.

The ceramic dielectric film desirably contains carbon, as in the other parts of the ceramic substrate. This is because the electrostatic electrode can be hidden and radiant heat can be used. Further, it is desirable that the ceramic dielectric film contains an alkali metal oxide, an alkaline earth metal oxide, and a rare earth oxide. This is because these act as sintering aids and can form a high-density dielectric film.

The thickness of the ceramic dielectric film is 50 to 50.
It is desirable to be 5000 μm. 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. In some cases, the thickness of the ceramic dielectric film is 50
If the thickness exceeds 00 μm, the distance between the silicon wafer and the electrostatic electrode becomes long, and the ability to adsorb the silicon wafer is reduced. The thickness of the ceramic dielectric film is more preferably 100 to 1500 μm.

Examples of the electrostatic electrode formed in 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. 4 and 5 are horizontal sectional views schematically showing electrostatic electrodes in another electrostatic chuck.
In the electrostatic chuck 20 shown in FIG. 5, 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.

As shown in FIG. 1, 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.

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 ₂O₃), 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 content 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 1-50 parts of titania 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 be covered with a metal layer. The resistance heating element is a sintered body of metal particles, and is easily oxidized when exposed, and the oxidation changes the resistance value. Therefore, oxidation can be prevented by coating the surface with a metal layer.

The thickness of the metal layer is desirably 0.1 to 10 μm. 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, at least one selected from gold, silver, palladium, platinum, and nickel is preferable. 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 preferable to use a nickel foil or a stainless steel foil formed by patterning 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 conductor is provided on the surface and inside of the ceramic substrate of the present invention, and the conductor inside is at least one of a guard electrode and a ground electrode, the ceramic substrate is provided with a wafer prober. Function as

FIG. 6 is a sectional view schematically showing one embodiment of the wafer prober of the present invention, and FIG. 7 is a sectional view taken along line AA of the wafer prober shown in FIG. In the wafer prober 201, a groove 47 having a concentric circular shape in plan view is formed on the surface of the ceramic substrate 43 having a circular shape in plan view, and a plurality of suction holes 48 for sucking a silicon wafer are provided in a part of the groove 47. The chuck top conductor layer 42 for connecting to the electrode of the silicon wafer is formed in a circular shape on most of the ceramic substrate 43 including the groove 47.

On the other hand, on the bottom surface of the ceramic substrate 43, a heating element 49 having a concentric circular shape in plan view as shown in FIG. 3 is provided to control the temperature of the silicon wafer. Are connected and fixed to external terminal pins (not shown). Also, the ceramic substrate 4
Inside 3, a guard electrode 45 and a ground electrode 46 (see FIG. 7) having a lattice shape in plan view are provided for removing stray capacitors and noise. Guard electrode 45
The material of the ground electrode 46 may be the same as that of the electrostatic electrode.

The thickness of the chuck top conductor layer 42 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 42, 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 such a wafer prober, 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.

Next, a method for manufacturing a ceramic substrate according to the present invention will be described with reference to FIG.
Description will be made based on the cross-sectional views shown in (a) to (d).

(1) First, after mixing a ceramic powder such as an oxide ceramic, a nitride ceramic, and a carbide ceramic with a binder and a solvent to prepare a mixed composition, the green sheet 50 is formed by molding. Make it. When carbon is contained, the above-mentioned crystalline carbon or amorphous carbon is used and its amount is adjusted according to the desired properties. As the above-mentioned ceramic powder, for example, aluminum nitride, silicon carbide and the like can be used, and if necessary, a sintering aid such as yttria may be added.

When amorphous carbon is used as carbon, it is desirable to produce amorphous carbon, but a material that becomes amorphous carbon may be mixed in the green sheet. For example, a pure amorphous carbon can be 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. As the crystalline carbon, crystalline carbon black or a material obtained by pulverizing graphite can be used.

Since several or one green sheet 50 to be laminated on a green sheet on which an electrostatic electrode layer printed body 51 to be described later is formed is a layer to be a ceramic dielectric film, depending on the purpose and the like, The composition may be different from that of the ceramic substrate. Alternatively, a ceramic substrate may be manufactured first, an electrostatic electrode layer may be formed thereon, and a ceramic dielectric film may be formed 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.

(2) Next, the green sheet 50 is printed with a conductive paste to be an electrostatic electrode layer and a resistance heating element. 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 conductive 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 kind of 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.

(3) Next, as shown in FIG. 8A, the green sheet 5 having the prints 51, 52, 53, 54
And a green sheet 50 having no printed body. Several or one green sheet 50 is laminated on the green sheet on which the electrostatic electrode layer printed body 51 is formed. The reason why the green sheet 50 having no printed body is laminated on the side where the resistance heating element is formed is to prevent the end face of the through hole from being exposed and being oxidized during firing for forming the resistance heating element. . 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.

(4) Next, as shown in FIG. 8B, 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.

(5) Next, as shown in FIG. 8C, 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.

(6) 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, and bismuth-tin 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
In the case of manufacturing a wafer prober, for example, as in the case of an electrostatic chuck, a ceramic substrate in which a resistance heating element is embedded is first manufactured, and then a ceramic substrate is manufactured. May be formed on the surface of the substrate, and then a metal layer may be formed by performing sputtering, plating, or the like on the surface portion where the groove is formed.

[0074]

The present invention will be described in more detail below. (Examples 1 to 3) Hot plate (see FIG. 9) (1) Aluminum nitride powder (average particle size: 1.1 μm, manufactured by Tokuyama Corporation) 100 baked in air at 500 ° C. for 1 hour
Parts by weight, 4 parts by weight of yttrium oxide (Y ₂ O ₃ : yttria, average particle diameter 0.4 μm), and 11.5 parts by weight of an acrylic resin binder are mixed, put into a hexagonal column mold, and put in a nitrogen atmosphere at 1890. Hot pressing was performed for 3 hours at a temperature of 150 ° C. and a pressure of 150 kg / cm ² to obtain an aluminum nitride sintered body. This aluminum nitride sintered body was processed into a disk shape, and by changing the amount of surface polishing, a diameter of 280 mm was obtained.
19 mm in thickness (Example 1), 310 mm in diameter, 5 m in thickness
m (Example 2), a ceramic substrate having a diameter of 350 mm and a thickness of 3 mm (Example 3) were obtained. (2) Bottom surface 91 of ceramic substrate 91 obtained in (1) above
The conductor paste was printed on a by screen printing. The printing pattern was a concentric pattern as shown in FIG. As the conductor 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 based on 100 parts by weight of silver, lead oxide (5% by weight), zinc oxide (55% by weight), silica (10% by weight), and boron oxide (25% by weight). % By weight) and 7.5% by weight of a metal oxide composed of alumina (5% by weight). Also,
The silver particles had an average particle size of 4.5 μm and were scaly.

(3) Next, the sintered body on which the conductor paste is printed is heated and fired at 780 ° C. to obtain silver in the conductor paste,
The lead was sintered and baked on a ceramic substrate 91 to form a resistance heating element 92. Silver-lead resistance heating element 9
No. 2 has a thickness of 5 μm, a width of 2.4 mm, and a sheet resistivity of 7.
It was 7 mΩ / □. (4) Nickel sulfate 80 g / l, sodium hypophosphite 24 g / l, sodium acetate 12 g / l, boric acid 8 g / l
1) The sintered body prepared in the above (4) is immersed in an electroless nickel plating bath comprising an aqueous solution containing 6 g / l of ammonium chloride, and a 1 μm thick metal coating layer 92 a is formed on the surface of the silver-lead heating element 92. (Nickel layer) was deposited.

(5) A silver-lead solder paste (manufactured by Tanaka Kikinzoku) was printed by screen printing on a portion where a terminal for securing connection to a power supply was to be formed, to form a solder layer. Next, a Kovar terminal pin 93 was placed on the solder layer, and heated and reflowed at 420 ° C. to attach the terminal pin 93 to the surface of the heating element 92 (metal coating layer 92a). (6) A thermocouple for temperature control is inserted into the bottomed hole 94,
Fill the polyimide resin, cured at 190 ℃ 2 hours,
A ceramic heater 90 (see FIG. 9) was obtained.

(Test Examples 1 to 3) Diameter: 240 mm, thickness: 5 mm (Test Example 1), diameter: 310 mm, thickness: 30
mm (Test Example 2), diameter 300 mm, thickness 17 mm
Then, a hot plate was manufactured in the same manner as in Example 1 except that adjustment was made so that Y ₂ O ₃ was not added (Test Example 3). In Test Example 3, a metal foil serving as a resistance heating element was buried in a mold, and the formation position of the heating element was 33% from the back surface. (Test Examples 4 to 6) A heating element was not provided, the diameter was 240 mm,
Thickness 5 mm (Test Example 4), diameter 310 mm, thickness 30 mm (Test Example 5), diameter 300 mm, thickness 17
A hot plate was manufactured in the same manner as in Example 1 except that the thickness was adjusted to mm (Test Example 6).

With respect to the hot plates according to Examples 1 to 3 and Test Examples 1 to 6, 450
The amount of warpage at ° C., the temperature rise time, the surface temperature uniformity, and the amount of oxygen were examined. However, in the hot plates according to Test Examples 4 to 6, only the amount of warpage was examined. The results are shown in Table 1.

(Examples 4 to 6) Alumina hot plate (1) Alumina: 93% by weight, SiO ₂ : 5% by weight, C
aO: 0.5% by weight, MgO: 0.5% by weight, Ti
O _2: 0.5% by weight, of acrylic binder: by using 0.5 parts by weight of 1-butanol and ethanol consisting of alcohol 53 parts by weight were mixed paste, a doctor blade method: 11.5 parts by weight, dispersing agent Perform molding,
A green sheet 50 having a thickness of 0.47 mm was obtained. (2) Next, after drying these green sheets at 80 ° C. for 5 hours, the green sheets that need to be processed are punched with a diameter of 1.8 mm, 3.0 mm, and 5.0 m.
A portion serving as a through hole for inserting a lifter pin for a semiconductor wafer m and a portion serving as a through hole for connecting to an external terminal were provided.

(3) 100 parts by weight of tungsten particles having an average particle diameter of 3 μm, 1.9 parts by weight of an acrylic binder, α
3.7 parts by weight of terpineol solvent and 0.2 dispersant
The conductive paste B was prepared by mixing parts by weight. The conductive paste B was printed on the green sheet 50 by screen printing to form a conductive paste layer. The printing pattern is
A concentric pattern was used.

(4) Further, the conductive paste B was filled in the through-holes for through holes for connecting external terminals.
Green sheet 50 on which pattern of resistance heating element is formed
Further, 34 to 60 green sheets 50 on which no conductor paste is printed are printed on the upper side (heating surface) and 13 to 3 green sheets are printed on the lower side.
Zero sheets were laminated, and they were pressed at 130 ° C. under a pressure of 80 kg / cm ² to form a laminate (FIG. 8A). Table 2 shows the formation positions of the heating elements.

(5) Next, the obtained laminate is placed in air for 6 hours.
Degreasing at 00 ° C for 5 hours, 1600 ° C, pressure 150kg /
and 2 hour hot pressed at cm ^2, and to obtain an alumina plate like body having a thickness of 3 mm. By changing the processing conditions and polishing conditions, the diameter 28
0 mm, thickness 19 mm (Example 4), diameter 310 mm,
Thickness 5 mm (Example 5), diameter 350 mm, thickness 3 mm
An alumina ceramic substrate of (Example 6) was obtained. These ceramic substrates have a thickness of 6 μm and a width of 10 m inside.
m of the resistance heating element 5.

(6) Next, the plate obtained in (5) 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.

(7) Further, the portions where the through holes are formed are cut out to form blind holes 13 and 14 (FIG. 8).
(C)) The gold holes made of Ni-Au were used in the blind holes 13 and 14 to heat and reflow at 700 ° C. to connect the external terminals 6 and 18 made of Kovar (FIG. 8D). 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. (8) Next, a plurality of thermocouples for temperature control were buried in the bottomed holes, and the production of a hot plate having a resistance heating element was completed.

(Test Examples 7 to 9) The diameter of the ceramic substrate was 240 mm, the thickness was 5 mm (Test Example 7), and the diameter was 310.
mm, thickness 30 mm (Test Example 8), diameter 300 m
m, thickness 17 mm, using aluminum nitride, Y ₂
Except for adjusting to not contain O ₃ (Test Example 9),
A ceramic substrate was manufactured in the same manner as in Examples 4 to 6.
Table 2 shows the formation positions of the heating elements.

(Test Examples 10 to 12) Without a heating element, the diameter was 240 mm, the thickness was 5 mm (Test Example 10), the diameter was 310 mm, the thickness was 30 mm (Test Example 11), and the diameter was 3
A hot plate was manufactured in the same manner as in Examples 4 to 6, except that the thickness was adjusted to 00 mm and the thickness was adjusted to 17 mm (Test Example 12).

Test Example 13 A hot plate was manufactured in the same manner as in Example 5, except that 20 green sheets 50 were laminated on the upper side (heating surface) and 19 on the lower side. (Test Example 14) A hot plate was manufactured in the same manner as in Example 5, except that 10 green sheets 50 were stacked on the upper side (heating surface) and 29 green sheets were stacked on the lower side.

The hot plates according to Examples 4 to 6 and Test Examples 7 to 14 were prepared by the following method.
The amount of warpage at 0 ° C., the temperature rise time, and the surface temperature uniformity were examined. However, with the hot plates according to Test Examples 10 to 12, only the amount of warpage was examined. The results are shown in Table 2.

Examples 7 to 9 Production of AlN Electrostatic Chuck with Heater (FIGS. 1 to 3) (1) Next, aluminum nitride powder (made by Tokuyama Corporation, fired at 500 ° C. for 1 hour in air) Average particle size 1.1 μm)
100 parts by weight, yttria (average particle size: 0.4 μm)
1, 2, 4 parts by weight, acrylic binder 11.5 parts by weight,
Using a paste in which 0.5 part by weight of a dispersant and 53 parts by weight of alcohol composed of 1-butanol and ethanol were mixed, molding was performed by a doctor blade method to obtain a green sheet 50 having a thickness of 0.47 mm.

(2) Next, these green sheets 50
After drying at 80 ° C. for 5 hours, a green sheet requiring processing is punched into a 1.8 mm-diameter.
A portion serving as a through hole for inserting a lifter pin of a semiconductor wafer of 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 conductive paste A
Was printed on the green sheet 50 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 50.

(4) Further, a conductive paste B was filled in a through hole for a through hole for connecting an external terminal.
Green sheet 50 on which pattern of resistance heating element is formed
Further, 34 to 60 green sheets 50 on which no tungsten paste is printed are laminated on the upper side (heating surface) and 13 to 30 green sheets are laminated on the lower side, and a green paste on which a conductive paste layer composed of an electrostatic electrode pattern is printed. The sheets 50 are stacked, and two green sheets 50 on which the tungsten paste is not printed are further stacked thereon.
The laminate was formed by pressing at 80 ° C. and a pressure of 80 kg / cm ² (FIG. 8A).

(5) Next, the obtained laminate was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. under a pressure of 150 ° C.
By hot pressing at 3 kg / cm ² for 3 hours, changing the processing conditions and the polishing conditions, the diameter is 280 mm, the thickness is 19 mm (Example 7), the diameter is 310 mm, the thickness is 5 mm (Example 8), the diameter is 350 mm, and the thickness is 3 mm. (Example 9) A substrate having a resistance heating element 5 having a thickness of 6 μm and a width of 10 mm and a thickness of 1
0 μm chuck positive electrostatic layer 2, chuck negative electrostatic layer 3
A plate made of aluminum nitride having
(B)). Table 3 shows the formation positions of the heating elements.

(6) Next, the plate obtained in (5) 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.

(7) Further, the portions where the through holes are formed are cut out to form blind holes 13 and 14 (FIG. 8).
(C)) The gold holes made of Ni-Au were used in the blind holes 13 and 14 to heat and reflow at 700 ° C. to connect the external terminals 6 and 18 made of Kovar (FIG. 8D). 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.

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

(Test Examples 15 to 17) The ceramic substrate had a diameter of 240 mm, a thickness of 5 mm (Test Example 15), a diameter of 310 mm, a thickness of 30 mm (Test Example 16), and a diameter of 3
300 mm, without the addition of _Y 2 _{O 3} at 17mm thickness except for adjustment (Test Example 17) As was producing a ceramic substrate in the same manner as in Example 7-9.

(Test Examples 18 to 20) Without a heating element, the diameter of the ceramic substrate was 240 mm, the thickness was 5 mm (Test Example 18), the diameter was 310 mm, and the thickness was 30 mm (Test Example 1).
9), diameter 300 mm, thickness 17 mm (Test Example 2)
A ceramic substrate was manufactured in the same manner as in Examples 7 to 9 except that the adjustment was performed to 0).

Test Example 21 A ceramic substrate was manufactured in the same manner as in Examples 7 to 9, except that 20 green sheets 50 were laminated on the upper side (heating surface) and 19 on the lower side. (Test Example 22) A ceramic substrate was manufactured in the same manner as in Examples 7 to 9, except that 10 green sheets 50 were stacked on the upper side (heating surface) and 29 green sheets were stacked on the lower side.

Test Example 23 A ceramic substrate was manufactured in the same manner as in Example 8, except that no yttria was added to aluminum nitride. (Test Example 24) A ceramic substrate was manufactured in the same manner as in Example 8, except that 40 parts by weight of yttria was added to aluminum nitride.

Examples 7 to 9 and Test Examples 15 to 24
Of the electrostatic chuck according to
The amount of warpage at 0 ° C., heating time, temperature uniformity, and oxygen amount were examined. However, for the electrostatic chucks of Test Examples 18 to 20, only the amount of warpage was examined. Table 3 shows the results.

Example 10 Production of Electrostatic Chuck (1) Aluminum nitride powder (average particle size: 1.1 μm, manufactured by Tokuyama Corporation) fired in air at 500 ° C. for 1 hour
0 parts by weight, 4 parts by weight of yttria (average particle size: 0.4 μm), 11.5 parts by weight of an acrylic binder, 0.5 part by weight of a dispersant, and 53 parts by weight of alcohol composed of 1-butanol and ethanol were mixed. The paste was molded by a doctor blade method to obtain a green sheet having a thickness of 0.47 mm.

(2) Next, these green sheets were
After drying at 0 ° C. for 5 hours, a green sheet requiring processing is punched into a 1.8 mm diameter, 3.0 mm,
A portion serving as a through hole for inserting a lifter pin of a 5.0 mm semiconductor wafer 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 conductive paste A
Was printed on a green sheet by screen printing to form a conductive 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 on which the electrostatic electrode pattern is printed, one green sheet on which the tungsten paste is not printed is further laminated on the upper side (heating surface) and 48 green sheets are laminated on the lower side, and these are laminated at 130 ° C. and 80 kg / cm ^2. To form a laminate.

(4) Next, the obtained laminate was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. under a pressure of 150
It was hot-pressed at kg / cm ² for 3 hours to obtain an aluminum nitride plate having a thickness of 3 mm. This was cut out into a disk shape of 300 mm, and a plate-like body made of aluminum nitride having a chuck positive electrode electrostatic layer 2 and a chuck negative electrode electrostatic layer 3 with a thickness of 10 μm inside.

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

(6) Next, a resistance heating element was printed on the side opposite to the wafer processing surface. For printing, a conductor paste was used. The conductor paste is Solvest PS603 manufactured by Tokurika Kagaku Kenkyusho, which is used to form through holes in printed wiring boards.
D was used. This conductor paste is a silver / lead paste, and is a metal oxide composed of lead oxide, zinc oxide, silica, boron oxide, and alumina (the weight ratio of each is 5/5).
5/10/25/5) is 7.5 with respect to 100 parts by weight of silver.
Parts by weight were included. The silver had a scaly shape with an average particle size of 4.5 μm.

(7) The plate on which the conductive 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 is 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 A nickel layer 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. The resistance heating element made of silver sintered body has a thickness of 5μ.
m, width 2.4 mm, and sheet resistance 7.7 mΩ / □
Met.

(8) Next, blind holes for exposing the through holes 16 were 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 recesses to obtain an electrostatic chuck. With respect to the obtained electrostatic chuck, the amount of warpage at 450 ° C., the temperature rising time, the surface temperature uniformity, and the amount of oxygen were examined. Table 3 shows the results.
It was shown to.

(Example 11) Production of wafer prober 201 (see Fig. 6) (1) Aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size: 1.1 µm) fired in air at 500 ° C for 1 hour 100
Parts by weight, 4 parts by weight yttria (average particle size 0.4 μm),
A mixed composition obtained by mixing 0.9 parts by weight of the amorphous carbon obtained in Example 1 and 53 parts by weight of an alcohol composed of 1-butanol and ethanol was molded using a doctor blade method, and the thickness was adjusted. A green sheet having a thickness of 0.47 mm was obtained.

(2) Next, the green sheet is 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, and an acrylic binder 3.0
Parts 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 conductive paste A. Further, 100 parts by weight of tungsten particles having an average particle diameter of 3 μm, 1.9 parts by weight of an acrylic binder, 3.7 parts by weight of an α-terpineol solvent, and 0.2 parts by weight of a dispersant were mixed to form 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, conductive paste B was filled in through holes for through holes for connecting to terminal pins.

Further, 50 sheets of printed green sheets and unprinted green sheets were laminated and 1
A laminate was produced by integrating at 30 ° C. under 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 /
It was hot-pressed at ² cm for 3 hours 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 45 and the ground electrode 46
Is 10 μm, the formation position of the guard electrode 45 is 1 mm from the wafer processing surface, and the formation position of the ground electrode 46 is
It was 1.2 mm from the wafer processing surface. The conductor non-forming region 46a of the guard electrode 45 and the ground electrode 46
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 treatment with SiC or the like is performed on the surface to form a concave portion for a thermocouple and a wafer adsorption surface. Groove 47 (width 0.5 mm, depth 0.5 mm)
Was provided.

(6) Further, a layer for forming the heating element 49 was printed on the surface facing the wafer processing 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 conductive paste was printed was heated and fired at 780 ° C. to sinter silver and lead in the conductive paste and to sinter the ceramic paste on the ceramic substrate 43. 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 49.
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 are as follows: atmospheric pressure 0.6 Pa, temperature 100 ° C., electric power 2
00W, and the sputtering time was adjusted for each metal within the range of 30 seconds to 1 minute. From the image of the X-ray fluorescence spectrometer, the thickness of the obtained film was 0.3 μm for the titanium layer.
m, the molybdenum layer was 2 μm, and the nickel layer was 1 μm.

(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 composed of 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 is formed from the groove 47 to the back surface by drilling, and a blind hole (not shown) for exposing the through hole 16 is provided. A Ni-Au alloy (81.5% by weight of Au, Ni1
An external terminal pin made of Kovar was connected by heating and reflowing at 970 ° C. using a brazing filler metal consisting of 8.4% by weight and 0.1% by weight of impurities. External terminal pins made of Kovar were formed on the heating element via solder (90% by weight of tin / 10% by weight of lead).

(11) Next, a plurality of thermocouples for temperature control were buried in the recesses to obtain a wafer prober heater 201. Regarding the obtained wafer prober heater 201, 2
The amount of warpage at 00 ° C., the temperature rise time, and the amount of oxygen were examined. Table 3 shows the results.

(Examples 12 to 14) 100 parts by weight of silicon carbide powder (average particle size 1.1 μm, manufactured by Yakushima Electric Works) baked at 500 ° C. for 1 hour, SiC electrostatic chuck with heater, 4 parts by weight of carbon, acrylic 11.5 parts by weight of binder, 0.5 of dispersant
A green sheet 50 having a thickness of 0.47 mm was obtained by molding by a doctor blade method using a paste obtained by mixing 53 parts by weight of 1 part by weight and alcohol composed of 1-butanol and ethanol. Then, among these green sheets, a glass paste was applied to a green sheet for forming a conductor layer and a green sheet as an uppermost layer. In addition, a glass paste was applied to the upper and lower sides of the conductor paste on the green sheet on which the conductor layer was formed, so that a sandwich state was obtained. And (2) of Examples 7 to 9
Processing similar to (8) was performed to manufacture an electrostatic chuck. The diameter and thickness of the obtained electrostatic chuck and the position of the conductor layer in the electrostatic chuck were 280 mm in diameter, respectively.
19 mm thick, 45% from back (Example 12), diameter 3
10 mm, thickness 5 mm, 33% from back (Example 1
3), diameter 350mm, thickness 3mm, 20% from the back
(Example 14).

(Example 15) 100 parts by weight of silicon carbide powder (average particle size: 1.1 μm, manufactured by Yakushima Electric Works), 4 parts by weight of carbon, acrylic resin binder 11 .5 parts by weight and placed in a hexagonal column mold, in a nitrogen atmosphere,
Hot pressing was performed at 90 ° C. under a pressure of 150 kg / cm ² for 3 hours to obtain a silicon carbide sintered body. Then, the same processing as in (2) to (6) of Example 1 was performed to manufacture a ceramic substrate. This sintered body is processed into a disc shape and has a diameter of 30.
0 mm and a thickness of 3 mm (Example 15). A glass paste was applied to the surface and baked at 1000 ° C. in air to form an insulating layer. A plate was obtained.

(Test Examples 25 to 27) The same as Example 15, except that the diameter was 240 mm, the thickness was 5 mm, and 33%
(Test Example 25), diameter 310 mm, thickness 30 mm, 33% from the back surface (Test Example 26), diameter 240 m, thickness 17 m
m, 33% from the rear surface, and manufactured under the condition that the SiC was not fired (Test Example 27). For Examples 12 to 15 and Test Examples 25 to 27, the amount of warpage at 450 ° C., the temperature rise time,
The surface temperature uniformity and oxygen content were examined. Table 4 shows the results.

(Test Example 28) The same as Test Examples 6 and 14, except that a through hole for a lifter pin was not formed. When the through hole for the lifter pin was not formed, the warpage was only about 10 μm even when the temperature was raised to 450 ° C.

The ceramic substrates according to the above Examples and Test Examples
The plate was evaluated by the following method.Evaluation method  (1) Uniformity of surface temperature Thermoviewer (IR162012 manufactured by Nippon Datum Co., Ltd.)
0012) on the wafer processing surface of the ceramic substrate
Measure the temperature at each location in the
Was determined.

(2) Temperature Rise Characteristics The time required to raise the temperature to 450 ° C. was measured. (3) Warpage The temperature was raised to 450 ° C., cooled to 25 ° C., and the warpage was measured using a shape measuring device (Nanoway manufactured by Kyocera Corporation).

(4) Oxygen content A sample sintered under the same conditions as the sintered body according to the example was pulverized in a tungsten mortar, and 0.01 g of the sample was collected to obtain a sample heating temperature of 2200 ° C. and a heating time of 30 minutes. Oxygen in seconds
The measurement was performed with a simultaneous nitriding analyzer (TC-136, manufactured by LECO).

[0135]

[Table 1]

[0136]

[Table 2]

[0137]

[Table 3]

[0138]

[Table 4]

As is clear from the results shown in Tables 1 to 4, the ceramic substrate such as the hot plate according to the embodiment has a short temperature rising time, is excellent in temperature followability, and is excellent in surface temperature uniformity. . Further, the amount of warpage at a high temperature can be reduced.

As described above, in the present invention, since the thickness of the ceramic substrate is 25 mm or less, a practically uniform temperature distribution can be given to the wafer processing surface.
For example, when a semiconductor wafer or the like is placed, breakage or the like due to non-uniform temperature of the wafer processing surface can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing an electrostatic chuck which is an embodiment of a ceramic substrate for a semiconductor manufacturing / inspection apparatus of 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 cross-sectional view schematically illustrating an example of an electrostatic electrode of the electrostatic chuck.

FIG. 5 is a cross-sectional view schematically illustrating an example of an electrostatic electrode of the electrostatic chuck.

FIG. 6 is a cross-sectional view schematically showing a wafer prober as one embodiment of the ceramic substrate of the present invention.

FIG. 7 is a sectional view taken along line AA of the wafer prober shown in FIG. 6;

FIGS. 8A to 8D are cross-sectional views schematically showing a part of the manufacturing process of the electrostatic chuck.

FIG. 9 is a cross-sectional view schematically showing a hot plate as one embodiment of the ceramic substrate of the present invention.

[Explanation of symbols]

 101 electrostatic chuck 1, 43 ceramic substrate 2, 22, 32a, 32b chuck positive electrode electrostatic layer 3, 23, 33a, 33b chuck negative electrode electrostatic layer 2a, 3a semicircular portion 2b, 3b comb tooth portion 4 ceramic dielectric Film 5, 49 Resistance heating element 6, 18 External terminal pin 9 Silicon wafer 11 Bottom hole 12 Through hole 16 Through hole 42 Chuck top conductor layer 45 Guard electrode 46 Ground electrode 47 Groove 48 Suction hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 3/16 H05B 3/16 3/20 393 3/20 393

Claims (12)

[Claims] 1. A ceramic substrate having a conductor on the surface or inside of a ceramic substrate, said ceramic substrate containing oxygen, said ceramic substrate being disc-shaped, having a diameter exceeding 250 mm and a thickness of The height is 25mm
A ceramic substrate for a semiconductor manufacturing / inspection apparatus characterized by the following. 2. The ceramic substrate according to claim 1, wherein the ceramic is a nitride ceramic or an oxide ceramic. 3. The ceramic substrate according to claim 1, wherein the ceramic is a carbide ceramic. 4. The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 1, which is used in a temperature range of 100 to 700 ° C. 5. The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 1, comprising a plurality of through holes into which lifter pins of the semiconductor wafer are inserted. 6. The semiconductor manufacturing device according to claim 1, wherein the conductor is formed in a region from a side surface opposite to a wafer processing surface of the ceramic substrate to a position of 60% in a thickness direction.・ Ceramic substrate for inspection equipment. 7. A ceramic substrate having a conductor on a surface of the ceramic substrate, wherein the ceramic substrate has a disk shape, a diameter exceeding 250 mm, and a thickness of 25 mm.
mm or less, the ceramic substrate for a semiconductor manufacturing / inspection apparatus. 8. The ceramic substrate according to claim 7, wherein the ceramic is an oxygen-containing nitride ceramic or oxide ceramic. 9. The ceramic substrate according to claim 7, wherein the ceramic is an oxygen-containing carbide ceramic. 10. The ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 7, wherein a conductor is formed on a side opposite to a processing surface of the wafer. 11. The method according to claim 7, wherein the semiconductor device is used in a temperature range of 100 to 700 ° C.
Ceramic substrate for inspection equipment. 12. The semiconductor device according to claim 7, comprising a plurality of through holes for inserting lifter pins of the semiconductor wafer.
A ceramic substrate for a semiconductor manufacturing / inspection apparatus according to claim 1.