JP2001114574A - Ceramic board for producing and inspecting semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a cement board for producing and inspecting a semiconductor using a nitride ceramic sintered compact having thermal characteristics for suppressing the deterioration of thermal conductivity in a high-temperature region. SOLUTION: This ceramic board for producing and inspecting the semiconductor is obtained by arranging a thermal diffuser in the nitride ceramic sintered compact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic plate for manufacturing and testing semiconductors using nitride ceramics, which is mainly used in the semiconductor industry.

[0002]

2. Description of the Related Art Conventionally, as an application of a ceramic material for a field related to a semiconductor product, a package for housing a semiconductor element, a hybrid integrated circuit device mounted with a semiconductor element and various other electronic parts, etc. Ceramic materials such as alumina have been widely used for insulating substrates for various wiring boards such as.

On the other hand, in recent years, in a semiconductor manufacturing apparatus such as a dry etching apparatus and a chemical vapor deposition apparatus, aluminum nitride has attracted attention as a material because of its excellent thermal conductivity and corrosion resistance as described later. , Such as an electrostatic chuck, a heater, a susceptor, or a wafer prober for a probing process using a nitride ceramic sintered body.

That is, aluminum nitride and silicon nitride have a thermal conductivity of about 100 to 200 W / mK at room temperature and have excellent thermal conductivity, and a CF for etching gas and cleaning gas used in the apparatus. _This is because they are also excellent in corrosion resistance to highly corrosive gases such as ₄ .

[0005] As described above, the use of sintered bodies such as aluminum nitride has been progressing.
Thermal conductivity decreases in a high temperature region of 0 ° C. or higher. In this regard, it is possible to suppress a decrease in thermal conductivity in such a high-temperature region, or to adjust a desired thermal conductivity to obtain desired thermal characteristics, in particular,
A nitride ceramic sintered body that obtains a desired thermal conductivity in a high temperature region is not known.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned situation, and provides a nitride ceramic sintered body having thermal characteristics for suppressing a decrease in thermal conductivity in a high temperature region. An object of the present invention is to provide a ceramic plate for use in semiconductor manufacture and inspection.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention have conducted intensive experiments and researches. As a result, it has been found that a thermal diffusion material is buried in a nitride ceramic sintered body, thereby improving the material. It has been found that a high quality sintered body can be obtained. Here, the heat diffuser means that heat is generated or unevenly distributed due to heat generated by an internal heating element, external heating, or the like, and the heat is dispersed and transmitted to a desired peripheral area. Say.

[0008] Based on such findings, the present inventors have taken a measure according to claim 1 of the present invention as a measure taken by the present inventors to obtain a nitride ceramic sintered body that reduces the degree of decrease in thermal conductivity in a high temperature region. A ceramic plate for semiconductor production and inspection is characterized in that a heat spreader is disposed in a nitride ceramic sintered body.

Among nitride ceramics, aluminum nitride, in particular, has a low thermal conductivity in a high-temperature region of 300 ° C. or higher. However, a heat spreader is disposed in a sintered body, and this heat spreader contributes to heat conduction. In addition, it suppresses a decrease in the thermal conductivity of the aluminum nitride sintered body in a high temperature region.

According to a second aspect of the present invention, there is provided a ceramic plate for manufacturing and inspecting a semiconductor, wherein the heat diffusion member is made of a metal material or a ceramic material containing a high melting point metal as a main component. The metal-based material or the ceramic material has a small decrease in thermal conductivity in a high-temperature region. The high melting point is 1500
A melting point of not less than ° C.

According to a third aspect of the present invention, there is provided a ceramic nitrided ceramic sintered body for manufacturing and inspecting a semiconductor, wherein the metal-based material includes at least one of tungsten, molybdenum, and a noble metal. Since it has a high melting point and a high thermal conductivity, it can be fired simultaneously with a nitride ceramic sintered body. The precious metals are gold, silver,
Platinum, palladium, rhodium, osmium and the like.

According to a fourth aspect of the present invention, there is provided a ceramic sintered compact for manufacturing and inspecting a semiconductor, wherein the metal-based material includes at least one of tungsten carbide and molybdenum carbide. Since the carbide metal has a high melting point and a high thermal conductivity, it can be co-fired with the nitride ceramic sintered body.

According to a fifth aspect of the present invention, there is provided a ceramic ceramic nitride body for semiconductor production and inspection, wherein the heat spreader is at a temperature of 300 ° C. or more than the nitride ceramic sintered body constituting the ceramic plate. It has a high thermal conductivity and is composed of at least one of oxide ceramic, nitride ceramic and carbide ceramic. These ceramic materials have a high thermal conductivity and a high melting point. It can be co-fired with ceramic and has a similar coefficient of thermal expansion.

According to a sixth aspect of the present invention, the shape of the heat spreader is substantially cylindrical, and the axial direction of the heat spreader is the same as that of the nitride ceramic sintered body. A plurality of the heat spreaders are arranged in a matrix in a top view substantially parallel to the thickness direction of the binder.

Due to the matrix-like arrangement, there is almost no difference between the firing shrinkage behavior and the thermal expansion / shrinkage with the nitride ceramic for each of the heat spreaders. In the present invention, aluminum nitride, silicon nitride, and boron nitride can be used as the nitride ceramic.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The structure and manufacturing method of an aluminum nitride sintered body (hereinafter, sometimes simply referred to as a sintered body) provided with a heat spreader according to the present invention will be described. In the following description,
The case of the heat spreader having the structure shown in FIG. 1 (pattern A) will be mainly described. For example, the heat spreader 25 having the structure shown in FIG.
(Upper end 25a, lower end 25b) (pattern B)
There are various ways of arranging the heat spreader within a range that does not lose the effect of the present invention.

Analysis of the thermal behavior of the arrangement of the heat spreader reveals that, in the case of pattern A, the deformation strain of the sintered body and the heat spreader during expansion or contraction during expansion or contraction of the sintered body is Dispersed into individual heat spreaders, each having a smaller volume than the size, and evenly distributed throughout the sintered body, resulting in distortion and cracking of the sintered body due to the overall thermal behavior. Etc. hardly occur. Therefore, a sintered body free from cracks or the like due to repetition of cooling and heating for a product to which the aluminum nitride sintered body is applied in a semiconductor manufacturing apparatus or the like can be obtained.

On the other hand, in the case of the pattern B, it is necessary to consider the ratio between the area and the thickness of the heat spreader so that the deformation strain does not affect the sintered body. The embedding is simpler than the pattern A because the shape is simple.

FIG. 1 is a side cross-sectional view of an aluminum nitride sintered body substrate 10 (hereinafter sometimes simply referred to as a substrate) according to the present invention. 10 shows a cross-sectional structure of FIG.
FIG. 4 is a partially cutaway plan view showing a state where a part of the thermal diffusion body 20 is exposed. In the thickness direction of the substrate 10, as shown in (a), both end portions 20a and 20b of the thermal diffusion member do not reach both the main surfaces 10a and 10b of the substrate 10. Reference numeral 30 indicates a heating element embedded in the substrate.

Then, in the plane direction, FIG.
As shown in FIG. 7, the heat spreaders 20a are embedded in a matrix in plan view. Here, burying means
(a), as described above, both ends of the heat spreader
It means that it has not reached both main surfaces of 10. in this way,
The advantage of embedding in the substrate is that since the heat spreader does not directly contact the outside, it is possible to prevent the metal constituting the heat spreader from reacting and changing the thermal conductivity.

At this time, the “matrix” arrangement is as follows.
The arrangement shown in FIG. 4 may be used. The side shape of the heat spreader is preferably circular when viewed in the axial direction.However, the shape is not limited to a circle.Although the side shape is often rectangular when viewed from the side, it may be a triangle, a parallelogram, or the like. Good. And the volume ratio of the total volume of the heat spreader when burying the heat spreader in aluminum nitride in the sintered body is:
1 to 75% by volume is desirable. If it is less than 1% by volume, it is difficult to prevent a decrease in the thermal conductivity at a high temperature. If it exceeds 75% by weight, the thermal conductivity itself decreases, and in any case, the decrease in the thermal conductivity at a high temperature cannot be suppressed. .

Next, the base material of the composition constituting such a heat spreader will be described. Hereinafter, for each substance, the thermal conductivity around room temperature (W / mK) in parentheses, and
The coefficient of thermal expansion (10 ⁻⁶ / ° C.) is described in order.

First, in terms of thermal conductivity, for example, copper (4
00, 16.5), gold (300, 14.2) and silver (428, 19.7) are considered to be applicable. Further, from the viewpoint of the coefficient of thermal expansion, since the coefficient of thermal expansion of aluminum nitride is 4 to 5 (× 10 ⁻⁶ / ° C.), it is expected that a base material having a numerical value close to this is suitable.

From such a viewpoint, the present inventors have earnestly
As a result of repeated experiments and trial production, the heat spreader was found to be a metal material mainly composed of a high melting point metal or a ceramic material (oxide ceramic, nitride ceramic,
And the like.

That is, the metal-based material mainly composed of a high melting point metal is, for example, tungsten (167,4.3), molybdenum.
(143,4.9), noble metal, or an alloy containing at least one of these as a main component has a large thermal conductivity and a small decrease in the thermal conductivity in a high temperature region. In addition, it is preferable because it can be formed by simultaneous firing in an aluminum nitride sintered body.

Accordingly, these metal materials can be used as a material for a heat spreader of an aluminum nitride sintered body to suppress a decrease in the coefficient of thermal expansion of the aluminum nitride sintered body in a high temperature region. The advantage is that readily available materials can be used.

At this time, the metal material may be used alone or in combination of two or more. Also,
The alloy may be any alloy that can be alloyed with the exemplified materials and melts a base material (element) that does not impair the properties of the base material in terms of heat conduction and thermal expansion.

Further, tungsten carbide (180 to 190, 4.
6) or any of molybdenum carbide (150, 4.5),
Alternatively, a carbide metal containing at least one of these as a main component has a high thermal conductivity, a small decrease in the thermal conductivity in a high temperature region, a high melting point, and a high melting point in the aluminum nitride sintered body. It is preferable because it can be formed by simultaneous firing. Therefore, these carbide metals can be buried in an aluminum nitride sintered body to be used as a thermal diffuser. Tungsten carbide and molybdenum carbide do not react with carbon in aluminum nitride, but are modified to have a thermal conductivity. Does not change.

As the ceramic material, beryllia
(250, 7.5) and silicon carbide (270, 3.7) can be used.

At 300 ° C., these materials are made of tungsten carbide 140 W / mK, molybdenum carbide 120 W / mK, beryllia 20
It has a thermal conductivity of 0 W / mK and silicon carbide 210 W / mK, and can be suitably used.

These ceramic materials have a higher thermal conductivity than a nitride ceramic sintered body at a temperature of 300 ° C. or higher, can be co-fired with aluminum nitride, and have similar thermal expansion coefficients. Therefore, these ceramic materials can be used as a heat spreader by being buried in an aluminum nitride sintered body, and there is an advantage that durability of the aluminum nitride applied product with respect to repeated thermal expansion and contraction is good.

When the heat diffusers having the respective compositions as described above are co-fired with aluminum nitride, the thermal characteristics of these metal materials and the like contribute to the thermal behavior of the aluminum nitride sintered body. The thermal conductivity of the aluminum nitride sintered body in which the heat spreader is embedded can be controlled by its composition, and the temperature characteristics of the thermal conductivity can be appropriately changed. Reduce the degree of decrease in thermal conductivity.

As described above, the heat spreader according to the present invention has an effect of remarkably widening the preferable operating temperature range of the aluminum nitride sintered body.

Accordingly, the present invention provides an aluminum nitride sintered body that meets various thermal characteristics required for various applications of aluminum nitride ceramic substrates such as, for example, heaters, susceptors, wafer probers, and the like. It has an epoch-making effect that the body can be used for the various uses.

Next, a method for manufacturing an aluminum nitride sintered body in which such a heat diffusion body is embedded will be described. Hereinafter, the case of manufacturing by the green sheet method will be described, but the present invention is not limited to this method.

First, a slurry for forming a sheet is prepared. That is, a predetermined amount of a binder, a plasticizer, a solvent thereof, a sintering aid, and the like are added to the aluminum nitride raw material powder in a predetermined amount, and the mixture is charged into a ball mill or the like and mixed and kneaded for a predetermined time. Thereby, a slurry is prepared.

Next, a green sheet is formed from the slurry. The green sheet is formed into a green sheet having a predetermined shape, for example, according to a standard sheet forming method such as a doctor blade method. At this time, in order to form a green sheet by the doctor blade method, a doctor blade device, a doctor blade forming machine including a forming base film, a drying furnace, and the like are used.

The slurry is temporarily stored in a liquid reservoir in the doctor blade device, and the base film is transported while being taken up by the take-up device. Drawn out in a thin layer. At this time, the thickness of the slurry is controlled by the gap, and the slurry is quantitatively drawn out onto the base film and sent to the drying furnace together with the base film.

Then, in a drying oven, the volatile solvent components and the like contained in the slurry are dried and evaporated to obtain a green sheet. Thereafter, a cavity for the heat spreader is formed at a desired position on the green sheet by punching or the like. Further, a desired heating element or the like is printed using a viscous liquid heating element paste containing a resistor element material for the heating element according to a standard method such as a screen printing method.

After that, the base sheet is peeled off from the green sheets, and the green sheets are laminated in order so as to form a predetermined laminated body, and then the cavity is filled with the constituent material of the heat spreader. .

At this time, the composition material for the heat spreader (hereinafter, referred to as the composition paste) is based on at least one of acrylic resin, ethyl cellulose, butyl cellosolve and polyvinyl alcohol with respect to the composition material powder. A composition paste prepared by uniformly kneading a binder and at least one solvent selected from α-terpione, glycol, ethyl alcohol and butanol is preferred.

At this time, the composition ratio of the metal-based material composition paste is generally 1.5 to 7.0 parts by weight of the binder and 5 to 20 parts by weight of the solvent with respect to 100 parts by weight of the metal material.

After the composition paste is filled in the hollow portion in this way, the composition paste is cut into a desired shape or the like, and is adjusted to a final shape as a formed product before firing.

Next, the formed component was decomposed in a stream of N ₂ under a decomposing condition at a holding temperature of 350 ° C. or higher. Thereafter, the substrate was hot-pressed at a holding temperature of 1800 ° C. in a stream of N ₂ to obtain an aluminum nitride sintered body substrate.

Through these steps, a desired aluminum nitride sintered body having a heating element and a heat diffusion element in the sintered body is manufactured.

Thus, the composition for the heat spreader is 16
At the temperature of about 00 to 2000 ° C., it can be fired simultaneously with aluminum nitride, and at the same time, matching of firing shrinkage behavior with aluminum nitride, in particular, approximate firing shrinkage can be obtained. As a result, there is almost no occurrence of protrusions or the like of the composition at the interface with the aluminum nitride, and a good interface between the composition and the aluminum nitride can be obtained.

Therefore, in the aluminum nitride sintered body in which the thermal diffusion material is embedded, the decrease in the thermal conductivity is small in a high temperature region, and the setting of the thermal conductivity and the temperature characteristics of the thermal conductivity are controlled by the composition ratio of the composition. In the case where the heating element is provided in the sintered body, the effect that the temperature rise of the heating element can be rapidly conducted is provided.

As a manufacturing method other than the green sheet method, for example, a cavity for a heat spreader is formed in a block-shaped formed body by a press molding method or the like, and a composition for a heat spreader is filled. Further, the aluminum nitride raw material powder may be filled so as to cover the filler and cover, followed by integrally firing.

EXAMPLES Hereinafter, examples of the present invention will be described. However, the present examples do not limit the present invention, but are merely examples. The process conditions described in the description of the embodiments are merely examples, and may be appropriately changed depending on the processing amount and the like.

First, 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama: average particle size 1.1 μm), 4 parts by weight of yttria (average particle size 0.4 μm), acrylic binder 1
Using a mixture obtained by mixing 1.5 parts by weight, a dispersant 0.5 parts by weight, and an alcohol mixture composed of 1-butanol and ethanol 53 parts by weight, a sheet is formed on a base sheet made of PET or the like by a doctor blade method. The molding was performed to obtain a green sheet having a thickness of 0.47 mm. After drying the green sheet at 80 ° C. for 5 hours, the through holes for the heat diffusion body were opened by punching according to a predetermined pattern.

As shown in Table 1, powders of various compositions for heat diffusing material were prepared, and 1.9 parts by weight of an acrylic binder and α-
3.7 parts by weight of a terpione solvent and 0.2 parts by weight of a dispersant were mixed to prepare a paste for a composition. At this time, the viscosity is 50 to 500 Pa · s (50,000 to 50,000).
0 cps).

Next, if desired, a predetermined heating element pattern is printed and formed on the green sheet.
The paste for the composition was filled in the through holes for the heat spreader according to the predetermined pattern of A or B above. In the comparative example, a sample is prepared without providing a heat spreader. Other points other than this point are the same as the embodiment.

The raw material used for the composition paste is, for example, tungsten having an average particle size of 3.0 μm.
Substantially spherical powder, molybdenum has an average particle size of 3.0 μm, and approximately spherical powder, tungsten carbide has an average particle size of 1.0 μm.
It is preferable to use a substantially spherical powder of m.

Then, 50 sheets of green sheets on which a heating element pattern or the like is printed and the paste for the composition is filled in the through-holes for the heat spreader are laminated and integrated under a pressure of 130 kg / cm ² to form a green sheet laminate. Was prepared. Due to the burying of the heat spreader, a required number of green sheets without through holes on the upper and lower main surfaces of the laminate and without filling with the composition are laminated.

Thereafter, the green sheet laminate was degreased in nitrogen gas at about 600 ° C. for about 5 hours, and
By hot pressing at 150 ° C. and a pressure of 150 kg / cm ² for 3 hours, a 4 mm-thick aluminum nitride plate-shaped ceramic substrate 11 was obtained. The obtained ceramic substrate 11 was used for a
A 30 mm disk was cut out. As a comparative example, a device without a heat diffuser embedded therein was similarly manufactured.

Here, in the case of the pattern A, the size of the thermal diffusion bodies 16 and 17 was 3.0 mm in diameter and 3.0 mm in depth, and the firing shrinkage was 60%. In the case of pattern B, it was 60%. When the thermal conductivity of each of the samples of the examples and the comparative examples was examined, the results shown in Table 1 were obtained (the thermal conductivity was measured at 25 ° C. and 400 ° C., respectively).

[Table 1]

Further, regarding these samples,
When the temperature change of the thermal conductivity at 25 to 400 ° C. was examined, the result shown in FIG. 3 was obtained. In FIG. 3, a solid line indicates Example 1 and a dashed line indicates a comparative example. In addition, it was observed that the speed at which the temperature rise due to the heat generated by the heating element 30 was conducted was improved.

From these results, in comparison with the comparative example in which the heat spreader was not provided, in the sample of the example, the thermal conductivity was increased even at around 400 ° C., and the temperature of the entire sintered body of the composition for the heat spreader was increased. A contribution to the properties is observed.

The thermal conductivity was measured by a laser flash method, specifically, a "Rigaku laser flash thermal constant measuring apparatus".

[0061]

When the composition for a heat diffuser thus composed is simultaneously fired with aluminum nitride, the thermal properties of these metallic materials and the like contribute to the thermal behavior of the aluminum nitride sintered body. In other words, the thermal conductivity of the aluminum nitride sintered body in which the heat diffuser is embedded can be controlled by its composition, and the temperature characteristics of the thermal conductivity can be appropriately changed. The degree of decrease in thermal conductivity in the high temperature region of the sintered body is reduced.

Therefore, when the heating element is also embedded in the sintered body, the temperature rise of the heating element can be rapidly conducted, and the present invention is applicable to various uses of the aluminum nitride ceramic substrate. It has an epoch-making effect that aluminum nitride sintered bodies matched to various required thermal properties can be used for the various applications, and promotes industrial use of aluminum nitride sintered bodies.

[Brief description of the drawings]

1A and 1B show a ceramic substrate having a heat spreader according to an embodiment of the present invention, wherein FIG. 1A is a side cross-sectional view, and FIG. FIG.

FIGS. 2A and 2B show a ceramic substrate having a heat spreader according to another embodiment of the present invention, wherein FIG. 2A is a side sectional view, and FIG. The top view of a state.

FIG. 3 is a graph showing the thermal conductivity of a ceramic substrate having a thermal diffuser according to an embodiment of the present invention.

FIG. 4 is a partially broken plan view showing an arrangement of a heat spreader according to another embodiment of the present invention.

[Explanation of symbols]

 10 ... ceramic substrate, 20 ... heat diffuser, 30 ... heating element

Claims (6)

[Claims] 1. A ceramic plate for manufacturing and inspecting a semiconductor, wherein a heat spreader is provided in a nitride ceramic sintered body. 2. The ceramic plate for semiconductor production and inspection according to claim 1, wherein said heat spreader is made of a metal material or a ceramic material containing a high melting point metal as a main component. 3. The metal-based material contains at least one of tungsten, molybdenum, and a noble metal.
A ceramic plate for semiconductor manufacture and inspection as described. 4. The ceramic plate for semiconductor production and inspection according to claim 2, wherein said metal-based material contains at least one of tungsten carbide and molybdenum carbide. 5. The thermal diffusion body has a higher thermal conductivity at a temperature of 300 ° C. or more than a nitride ceramic sintered body constituting a ceramic plate, and at least one of an oxide ceramic, a nitride ceramic, and a carbide ceramic. 2. The ceramic plate for semiconductor production and inspection according to claim 1, wherein the ceramic plate comprises any one kind. 6. The heat diffusion body has a substantially cylindrical shape,
2. The semiconductor manufacturing method according to claim 1, wherein an axial direction of said heat spreader is substantially parallel to a thickness direction of said nitride ceramic sintered body, and a plurality of said heat spreaders are arranged in a matrix form when viewed from above. Ceramic plate for inspection.