JP2001148280A - Hot plate unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot plate unit with good equal heating and temperature control. SOLUTION: The hot plate unit is equipped with a hot plate made of ceramic sintered body with a heating element at an opening part of a casing, which is made of ceramic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hot plate unit using ceramic.

[0002]

2. Description of the Related Art Semiconductor-applied products are extremely important products required in various industries. A typical example of a semiconductor chip is a silicon wafer obtained by slicing a silicon single crystal to a predetermined thickness. After fabrication, it is fabricated by forming various circuits and the like on this silicon wafer.

[0003] These various circuits and the like are manufactured by forming a conductive thin film or the like on a silicon wafer, applying an etching resist using a photosensitive resin or the like through a mask having a circuit pattern, and pattern-etching. Or by performing plasma etching or high frequency sputtering. For this reason, it is necessary to heat the wafer, and a hot plate using a substrate using a ceramic sintered body (sometimes called a ceramic substrate) has been often used in recent years.

On one main surface of the ceramic substrate, a layer of a resistance heating element (hereinafter referred to as a resistor) such as a so-called thick-film resistor including a powder of glass and a powder of a conductive substance is formed in a predetermined pattern. A terminal connection pad is formed on a part of the resistor pattern.

[0005] Terminal pins are soldered to the terminal connection pads, and a power supply is connected to the terminal pins via wiring. This ceramic substrate is placed in the opening of the casing to form a hot plate unit. And
A silicon wafer to be heated is placed on the upper surface side of the hot plate, and current is supplied in this state, whereby the silicon wafer is heated to several hundred degrees Celsius.

[0006]

However, the casing, which is a housing for supporting the ceramic substrate of such a hot plate unit, is made of, for example, metal aluminum or the like, and has a thermal conductivity of 209 W / m · K.
Degree of thermal conductivity. Therefore, it has been found that there is a problem in the heat retaining property of the hot plate, which has an unfavorable effect on the maintenance of the uniformity of the hot plate and the temperature controllability.

The requirements for the material of the casing include physical properties such as thermal conductivity, heat resistance, corrosion resistance, and electrical insulation, as well as rigidity and strength capable of supporting a hot plate.
In addition, although it is thought that there are various aspects such as good moldability, it is hard to say that materials that sufficiently satisfy these requirements have been sufficiently studied.

In addition, such a hot plate unit includes:
Since the casing is mainly used in a semiconductor manufacturing or inspection apparatus, it is also an issue to be considered that the surface of the casing is affected by light heat or volatile gas when used in the semiconductor manufacturing or inspection apparatus.

In view of the foregoing, the present invention has been made in view of the above-mentioned problems, and the material of the casing of the hot plate unit is made of a material having a good heat retaining property capable of sufficiently exhibiting the thermal characteristics of the ceramic substrate. Another object of the present invention is to provide a hot plate unit having excellent heat uniformity and temperature controllability.

[0010]

According to a first aspect of the present invention, there is provided a hot plate comprising a ceramic sintered body having a heating element installed in an opening of a casing. A hot plate unit, wherein the casing is made of ceramic. Ceramics have high heat resistance, high corrosion resistance, low thermal conductivity, and a coefficient of thermal expansion similar to that of the ceramics that make up the hot plate. Therefore, the joint between the casing and the hot plate can be heated and cooled. Is less likely to break.

The ceramic used in the present invention is at least one material selected from the group consisting of machinable ceramics, quartz glass, and a composite of a ceramic fiber and an inorganic binder. The machinable ceramic material has low thermal conductivity, extremely good heat resistance and corrosion resistance, and has sufficient rigidity as a casing. Further, machinable ceramics are excellent in machinability and can increase processing accuracy. Quartz glass has low thermal conductivity, extremely good heat resistance and corrosion resistance, and has sufficient rigidity as a casing.
The composite of ceramic fiber and inorganic binder is
A ceramic fiber hardened with an inorganic binder, has high toughness and is unlikely to crack. It is easy to mold and lighter than a dense ceramic body.

[0012]

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

Embodiment 1 FIG. 1 is a perspective explanatory view showing an example of a hot plate unit used in a semiconductor manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a partial side sectional view thereof. 3 and 4 are partial side sectional views of another example. In the drawings, the same elements are denoted by the same reference numerals.

The hot plate unit 1 has, as main components, a hot plate 3 which is circular in a top view and has a disk shape, and a casing 2 which can support the hot plate 3 at an end 2b (FIG. 2). The end 3b of the hot plate 3 and the end 2b of the casing are formed in a shape (FIG. 2 or FIG. 3) in which the ends can abut each other, and are integrated with a bonding layer 13 between the ends. ing.

Since the hot plate 3 is for heating and drying a semiconductor wafer, the hot plate 3 is generally formed in a circular shape when viewed from the top. However, the present invention is not limited to a circular shape but a rectangular shape. You may.

The hot plate 3 of this embodiment is a low-temperature hot plate for curing a silicon wafer coated with a photosensitive resin at 170 to 200 ° C. However, 2
Even in a temperature range of 00 ° C. or more, the following description is commonly applied.

The hot plate 3 is formed by providing a resistor pattern as a resistor 10 on a substrate 9 using a ceramic sintered body by baking or the like. The resistor pattern is formed concentrically or spirally on the lower surface side of the substrate. The material of the ceramic sintered body constituting the hot plate 3 and the detailed configuration of the hot plate will be described later.

Next, the casing 2 is a box-like member or a bathtub-like member without a bottom and having a bottom, and has an opening 2x having a circular cross section on its upper side, and can carry a hot plate 3. Further, it is formed in a shape capable of accommodating terminal pins and the like described later. And the casing 2 is a hot plate
It is preferable to have a heat retaining property for retaining the heat of No. 3 and to contribute to maintaining the uniformity of the hot plate 3 and to improve the temperature controllability when the resistor 10 is energized to generate heat.

Therefore, the requirements for the material used for the casing 2 include (1) physical properties such as thermal conductivity, heat resistance, corrosion resistance, and electrical insulation. In addition, (2) it has mechanical properties such as rigidity and strength capable of supporting the hot plate, and (3) the components such as the lead wires 6 required for the hot plate unit (see FIG. 2) are housed in the casing. (4) Hot plate unit is used mainly in semiconductor manufacturing and inspection equipment because it is necessary to drill through holes etc. to lead out the lead wires etc. Therefore, it is also a requirement that the surface of the casing is chemically stable against light heat, volatile gas and the like.

When a casing is manufactured using a material satisfying these requirements, the structure of the casing is as shown in FIG.
As shown in at least one, a double structure using a material that satisfies the requirement for at least one, or a multiple structure,
Further, an intermediate layer in consideration of thermal conductivity can be provided in the middle of the double structure. In FIG. 4, reference numeral 22 indicates a casing exterior made of another material.

The present invention relates to these casings.
It is characterized by using at least a material satisfying the above requirements. Therefore, the materials described below can be applied to a double structure or a combination of multiple structures.

Therefore, the present inventors have repeatedly and eagerly repeated trial production and evaluation tests and found that the following materials can be applied to the present casing.

In the present embodiment, so-called quartz glass is used as the material of the casing 2. Quartz glass is a one-component glass made of only a network-forming oxide containing only quartz (SiO ₂ ) as a component.

Such a quartz glass has a thermal conductivity of 0.1
About 1.5 W / m · K, which is significantly smaller than a metal material such as aluminum (209 W / m · K as described above). And the coefficient of thermal expansion (5-6 × 10 ⁻⁷ / ° C.) is low,
It has heat resistance, corrosion resistance, and electrical insulation.

Therefore, the heat from the hot plate 3
As the heat insulation to heat conduction to the semiconductor manufacturing equipment outside the hot plate unit is extremely excellent and the heat retention is good,
This has the effect of facilitating soaking and maintaining the temperature of the hot plate.

The quartz glass substrate is a hot plate
In addition to having mechanical properties such as rigidity and strength capable of supporting the 3, it is also possible to provide a through-hole or the like as a lead wire drawing hole 7 on the bottom surface. When processing is difficult, when molding the glass raw material by melt cooling, the through-hole portion may be molded in advance so as to be hollow. Therefore, a robust structure can be obtained as the hot plate unit 1. In addition, as shown in FIG.
The end 2c of the hot plate 3 and the end 3c of the hot plate 3 can be formed with a step or the like.

In addition, quartz glass has heat resistance up to about 1000 ° C. and has acid, alkali, organic solvent,
Because it has chemical stability against oxidizing gas, etc.
It is extremely suitable for use involving light heat, volatile gas, and the like in a semiconductor manufacturing apparatus.

This quartz glass usually contains 9% SiO ₂ .
9.5% or more of Na ₂ O, K ₂ O,
A small amount of B ₂ O ₃ , Al ₂ O ₃ or the like may be added.

The casing 2 is formed from quartz glass by melting natural quartz with an oxyhydrogen flame or by using SiCl.
It can also be prepared by a method such as oxidation or flame hydrolysis of ₄ . Since transparency is not required as in the case of other quartz glass applications, silica sand can be electrically melted.

In summary, the casing made of quartz glass has excellent heat insulation from the hot plate to heat conduction from the hot plate to the semiconductor manufacturing equipment and the like, and has good heat retention. The effect that becomes easy is produced.

The casing using quartz glass is
A robust structure can be provided as a hot plate unit, which has extremely good corrosion resistance to light heat and volatile gas and can be used with high durability in a semiconductor manufacturing apparatus. Furthermore, a casing using quartz glass has sufficient durability to a heat cycle.

Embodiment 2 In this embodiment, a machinable ceramic is used as the material of the casing.

The machinable ceramic refers to a sintered ceramic having a composition which is excellent in machinability among materials such as mica, alumina titanate, aluminum nitride, and boron nitride.

For example, mica is SiO_Two, K_TwoO, B
_TwoO_ThreeIs a mixture of synthetic mica and HS85
Hardness, 2.5g / cm^ThreeIt has a degree of density. For example,
B_TwoO _Three-K_TwoO-Al_TwoO_Three-MgO-SiO_TwoBased on
It is a mica sintered ceramic and has a heat resistant temperature of 100
0 ° C is possible and the coefficient of thermal expansion is (75-150) × 10 ^-7
It is.

Alumina titanate is composed of Al ₂ O ₃ and Ti
O ₂ as a main component, hardness of about HS50, 3.5 g / cm
^It has a density of about ³ . In addition, aluminum nitride-based
It is obtained by adding other nitrides to AlN and has a hardness of about HS 70 and a density of about 2.95 g / cm ³ .

Boron nitrides include BN + SiO ₂ , B
_{At least 2} O ₃ , Al ₂ O ₃ , CaO and the like are used, and have a hardness of about HS 70 and a density of about 2.95 g / cm ³ . One of the compositions exemplified above may be used, or two or more of them may be used in combination.

Each of these machinable ceramics has a thermal conductivity of about 0.42 to 2.93 W / m / K, and has heat resistance, corrosion resistance (acid and alkali), and electric insulation. Good thermal shock resistance. The thermal conductivity of the machinable ceramic can be adjusted by changing the composition of the additive in the above-described various main component material systems. Therefore, a plurality of types of machinable ceramics may be used in combination.

As described above, the casing using the machinable ceramic has extremely excellent heat insulating property against heat conduction from the hot plate to the semiconductor manufacturing apparatus and has good heat retaining property. The effect that becomes easy is produced.

The machinable ceramic has mechanical properties such as rigidity and strength capable of supporting the hot plate 3, and has a through hole (see FIGS. 2 to 4) as a lead wire drawing hole 7 in the bottom 2a. ) Etc. can be machined with a general lathe or drilling machine using a normal cutting tool or the like. Further, it is easy to enclose the frit glass in the structure of the sintered body or to metallize the frit glass.

As for the strength, for example, it does not have the strength of alumina or zirconia, which is a material of another system of the same sintered ceramic, but is sufficient for the casing 3 of the hot plate unit 1. Can exhibit characteristics such as heat resistance.

Examples of such machinable ceramics include, for example, “Macol” (trade name, Corning, USA) containing B ₂ O ₃ —Al ₂ O ₃ —SiO ₂ as a main component and containing fluorophlogopite, mica, and mica. "Mycarex" containing glass
(Nikko Chemicals, trade name, registered trademark) and the like.

In order to manufacture a casing using such machinable ceramics, a method of forming and shaping a casing having a desired size and shape in consideration of a firing shrinkage ratio, or a block-shaped method is used. It is preferable to cut the sintered body in the same manner as in the case of cutting from a metal block and shape it into a desired shape. In the former method,
A slightly larger casing may be formed, and after firing, may be finished and shaped into a desired size and shape.

The through hole serving as the lead wire insertion hole 7 can be formed by forming a mold so that the through hole can be formed, and forming a cavity by previously drilling the through hole portion. Alternatively, a through hole may be formed by machining after firing. In either method, as shown in FIG.
Steps and the like can be formed on the end 2c of 2x and the end 3c of the hot plate 3.

The machinable ceramics also have the advantages of being easy to use and suitable for small-volume production because the materials themselves and the cost of the manufacturing process are inexpensive and widely distributed.

In summary, therefore, the machinable ceramic material has excellent heat insulation from the hot plate to heat conduction to the semiconductor manufacturing equipment and good heat retention, so that the hot plate can be easily maintained at a uniform temperature and the temperature can be easily controlled. It has the following effects.

Further, a casing using a machinable ceramic material can provide a robust structure as a hot plate unit, has extremely good corrosion resistance to volatile gases and the like, and can be used with high durability in a semiconductor manufacturing apparatus. .
Furthermore, casings made of machinable ceramic materials can be easily formed by machining with a high degree of freedom in shape design, suitable for small-volume production, and easy to process through holes and the like drilled in the bottom surface, etc. Yes, and the material and manufacturing costs are low and inexpensive.

Embodiment 3 In this embodiment, a composite of a ceramic fiber and an inorganic binder is used. As the ceramic fiber, silica-alumina-based ceramic fiber, alumina fiber, silica fiber, glass fiber, or the like can be used.
The silica-alumina-based ceramic fiber is most preferably composed of 35 to 65% by weight of silica and the balance of alumina. Silica-alumina ceramic fibers are obtained by melting silica and alumina and blowing high-pressure air into amorphous fibers.

The inorganic binder is a colloidal solution of silica or alumina, an alkoxide of silica or alumina or a hydrolyzate thereof. As a molding method, ceramic fiber is dispersed in water, poured into a mold,
After dehydration under pressure, an inorganic binder can be poured into the mixture and cured to form a predetermined shape. After molding,
The fibers may be bonded by heating at 450 to 900 ° C.

The composite of such a ceramic fiber and an inorganic binder has a thermal conductivity of 0.29 W / m · K.
0.63 W / m · K and a thermal expansion coefficient of 1
It is as small as 0 to 30 ppm / ° C., and is excellent in heat resistance, corrosion resistance, and electric insulation. In addition, it has excellent heat insulation and heat retention, and is optimal as a hot plate casing.

Embodiment 4 A hot plate unit is manufactured using any of the casing materials described above. Hereinafter, the configuration of other members and a method of manufacturing the hot plate unit will be described.

Examples of the material of the hot plate include carbide ceramics, oxide ceramics, and nitride ceramics other than aluminum nitride.

For example, as an example of a carbide ceramic,
Metal carbide ceramics such as silicon carbide, zirconium carbide, titanium carbide, tantalum carbide, and tungsten carbide can be given, and examples of oxide ceramics include metal oxide ceramics such as alumina, zirconia, cordierite, and mullite. Can be. Further, examples of nitride ceramics include metal nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, and titanium nitride.

Of these ceramic materials, nitride ceramics and carbide ceramics are generally preferable to oxide ceramics because of their higher thermal conductivity. still,
These sintered materials may be used alone or in combination of two or more.

A hot plate using a nitride ceramic typified by aluminum nitride or another carbide ceramic has a small thermal expansion coefficient in addition to a coefficient of thermal expansion of these ceramic materials as compared with a metal. Also, since the heater substrate has rigidity in the sense that no warping or distortion occurs due to heating, the heater substrate can be made thinner and lighter than one made of a metal material such as aluminum.

In particular, aluminum nitride is preferable because it has excellent thermal conductivity, is hardly affected by light and heat in a semiconductor manufacturing apparatus, and has excellent corrosion resistance to processing gases and the like.

A substantially linear resistor 10 is formed on one main surface of the substrate 9 made of the ceramic material. The resistor is a conductive paste containing metal particles (e.g., an average particle size of about 5 μm and a substantially spherical silver particle) so that the resistance value can be variously set by controlling the shape to be formed (line width or thickness). This is a form in which a conductive paste layer having a predetermined pattern is formed by applying a predetermined pattern on the surface of the substrate and then baked to sinter the metal particles. Note that the resistor can also be provided in the substrate 9.

The sintering of the metal particles is sufficient if the metal particles are fused together and the metal particles and the ceramic substrate are fused. Also, as is well known, the smaller the width and the smaller the thickness, the higher the resistance value. And the form of the striated line is a wide, substantially straight line or curved line, and it is not necessary to be a geometrically strict straight line or curved line.
And it is desirable that it be smooth. Incidentally, a protective coating may be provided on the surface of the resistor.

A pad 10a as an external connection terminal is formed at an end of the resistor pattern. These pads 10
The base end of the terminal pin 12 made of a conductive material is soldered to a. As a result, electrical continuity between each terminal pin 12 and the resistor pattern can be obtained.

On the other hand, a lead wire is provided at the tip of each terminal pin 12.
A socket 6a at the distal end of 6 is fitted. Therefore, a current is supplied to the resistor pattern via the lead wires 6 and the terminal pins 12, and as a result, the temperature of the resistor pattern increases, and the entire hot plate 3 is heated.

At three places at the center of the hot plate, lift pins for supporting the semiconductor wafer W1 (FIG. 2) are provided.
A through hole (not shown) is provided. FIG.
In the figure, reference numeral 11 indicates a through hole for inserting the lift pin. These lift pins raise and lower the silicon wafer W1 while supporting the silicon wafer W1 at three points.

On the other hand, on the bottom 2a of the casing 2, there is formed a lead wire drawing hole 7 for inserting a lead wire for supplying a current to the resistor of the hot plate. A seal packing 8 is mounted in the lead wire drawing hole 7. Each lead wire 6 is inserted into the through hole of the seal packing 8 and then drawn out of the casing. A thermocouple (not shown) for temperature control is
The hot plate according to the invention is obtained embedded in 9.

Then, the hot plate 3 produced as described above is joined to the casing 2 and installed. As described above, the hot plate and the casing are formed in a shape such that the ends can abut each other.
A bonding layer using a synthetic resin, which will be described later, is provided and both are fixed.

The synthetic resin is preferably one having heat resistance and thermal shock resistance, capable of absorbing the difference in thermal expansion between the hot plate and the casing, and obtaining the adhesive strength between the hot plate and the casing.

Specific examples thereof include a polyimide resin, a silicone resin, and a fluororesin. The polyimide resin is a polymer compound obtained by reacting a carboxylic acid derivative having an acid imide bond with a diamine. For example, in the case of Kapton, a temperature range: 2
It has excellent heat resistance at 00 to 400 ° C and can be used in a wide temperature range.

The silicone resin is a high molecular compound having heat resistance and rubber elasticity in which a methyl group or an ethyl group is arranged in an alkyl group in a side chain of polysiloxane. Co., Ltd. "KE1830" (product number) if the adhesion at the two interfaces is good,
It can be dried and solidified at a relatively low temperature of about 100 ° C. to form a bonding layer. Silicone resins are suitable because they have excellent thermal shock resistance and can well absorb thermal expansion caused by repeated heating of a hot plate. Further, if it is a fluororesin, 50
The heat resistance of 0 ° C. can be secured, and the fluororesin is also excellent in heat insulation.

Thus, the hot plate and the casing are joined by providing the joining layer. The joining method is to apply a synthetic resin material to the joining layer portion at the end of the hot plate and the joining layer portion at the end of the casing, join them, and heat them while applying pressure in the direction perpendicular to the adhesive surface. Let it solidify.

The hot plate obtained in this way has a high thermal conductivity and can be formed with a reduced thickness, and its surface temperature is rapidly changed with respect to the temperature change of the resistor. This has a great advantage that the temperature controllability of following the temperature is excellent. Therefore, a hot plate with excellent temperature controllability and improved durability can be provided. Then, by installing a casing having good heat insulating property against heat conduction from the hot plate to the outside by the above-mentioned casing material and joining it to the hot plate with the synthetic resin, a heater excellent in temperature controllability can be provided.

The surface of the hot plate has a chuck top conductor layer 44 made of at least one metal selected from noble metals (gold, silver, platinum, palladium), nickel, tungsten, molybdenum, etc. Grooves 47 and air suction holes 48 are provided. In addition, a heating element 42 is provided inside, and the power supply 55 is configured to be energized through a terminal pin (not shown) provided in the blind hole 18, and a guard electrode 45, a ground electrode 46 are provided, and the through hole 16 and 17
A power supply (not shown) may be applied from the outside of the hot plate 43 made of a ceramic substrate via the substrate, and a wafer prober 201 as shown in FIG. 6 may be formed. In FIG. 5, reference numeral 51 indicates a portion where the conductor layer (guard electrode 45) is formed, and reference numeral 52 indicates a portion where the conductor layer is not formed. The guard electrode 45 and the ground electrode 46 can be made of tungsten, molybdenum, carbide of tungsten, and carbide of molybdenum.

A column 49 is formed at the bottom of the casing 40 as shown in FIG. 6 so that the hot plate 43 does not warp even when a probe tester pin (not shown) is pressed on the hot plate. It may be. The material of the column 49 may be the same as the material of the casing, or may be any of ceramic, metal, and the like used in the present invention.

Further, an electrostatic electrode can be embedded inside the hot plate to function as an electrostatic chuck. The electrode for the electrostatic chuck may be any of a pair of tooth types 61a and 61b as shown in FIG. 7A and a bipolar type 62 as shown in FIG. 7B. The electrostatic electrode can be made of tungsten, molybdenum, carbide of tungsten, and carbide of molybdenum.

EXAMPLE A specific example of a hot plate unit according to the present invention and a manufacturing method will be described. Quartz glass, machinable ceramic, a molded body of ceramic fiber and an inorganic binder were prepared as materials for the examples of the casing, and aluminum and a stainless alloy were prepared as comparative products.

The machinable ceramic used was "Mycalex" manufactured by Nikko Kasei. The composite of the ceramic fiber and the inorganic binder was produced as follows. 100 parts by weight of a ceramic fiber (trade name "IBI-WOOL" manufactured by IBIDEN Co., Ltd.) is dispersed in 200,000 parts by weight of water, put into a forming device made of a metal sintered body, pressed, dehydrated, and dried. It was a bottom-shaped molded body.

On the other hand, 104 parts by weight of ethyl silicate and 66 parts by weight of ethyl alcohol were mixed to form a uniform solution, and 18 parts by weight of water, 66 parts by weight of ethyl alcohol, and 0.1 part by weight were mixed.
One part by weight of 1N hydrochloric acid was added and stirred for 12 hours to obtain an inorganic binder. This inorganic binder was impregnated into a ceramic fiber compact, pressed again, dried at 80 ° C., and heat-treated at 600 ° C. for 30 minutes to obtain a composite of ceramic fiber and inorganic binder.

Table 1 shows the thermal expansion coefficient, the center temperature of the hot plate, and the outer peripheral temperature. In addition, the center temperature and the outer peripheral temperature of the hot plate were measured with a thermoviewer (IR162012-0012, manufactured by Nippon Datum Co., Ltd.). In addition, 14.7MPa (150kgf /
cm ² ) and the amount of warpage was determined. In the following examples, the process conditions are merely examples, and are set with appropriate changes depending on the sample size, the processing amount, and the like.

As a ceramic material for the hot plate, aluminum nitride powder (average particle size: 1.1 μm) 10
0 parts by weight, 4 parts by weight of yttria (average particle size 0.4 μm),
After mixing and kneading 12 parts by weight of an acrylic resin binder and alcohol, a granular powder was formed by a spray dryer method.

Next, the granular powder was charged into a molding die and molded into a flat plate to obtain a formed product. A through hole for inserting a semiconductor wafer support pin into the formed form;
A recess for embedding a thermocouple was formed by drilling.

The formed body in which the through holes and the recesses are formed is heated at about 1800 ° C. under a pressure of 19.6 MPa (200 kgf / c).
m ² ) to obtain a 3 mm-thick aluminum nitride plate-like sintered body. This was cut into a disk having a diameter of 210 mm to obtain a ceramic substrate for the hot plate 3.

According to a predetermined resistor pattern, a conductive paste was printed on the ceramic substrate by a screen printing method so as to dispose the resistor. The conductive paste used here is "Solbest PS603D" (manufactured by Tokuriki Chemical Laboratory).
It is. Incidentally, the average particle size of silver was 3 μm, and the shape was mainly scaly. The ceramic substrate on which the conductive paste was printed as described above was heated and fired at 800 ° C. to sinter silver and the like in the conductive paste to such an extent that metal fine particles and the like were fused to each other and baked on the ceramic substrate.

Next, as shown in FIG. 2, a silver-containing lead solder paste (made of alpha metal) is printed on the resistor 10 by a screen printing method to provide a solder layer. Place Kovar terminal pin 12 on the 4
After heating and reflow at 00 ° C., the terminal pin 12 was attached to the surface of the resistor 10.

Finally, a hot plate was joined to the casing with a silicone resin to obtain a hot plate unit. For these hot plate units,
Heating was performed under the same conditions up to a predetermined temperature, and heating was performed up to 180 ° C. under the same conditions, and the soaking time at this temperature without power supply was measured. And the current required to reach this temperature,
The power consumption was measured. Table 1 shows the results.

[Table 1]

From the results shown in Table 1, a hot plate having a good heat retaining property capable of sufficiently exhibiting the thermal characteristics of the ceramic substrate was obtained as a material for the casing, and a hot plate having excellent heat uniformity and temperature controllability was obtained. It has been found.

[0082]

According to the present invention, since the casing is made of a material having a low thermal conductivity, good heat resistance and corrosion resistance, and having sufficient rigidity as a casing, the apparatus for manufacturing a semiconductor from a hot plate using a hot heat can be used. The heat insulating property against heat conduction to the hot plate is excellent, and it is possible to easily maintain the temperature of the hot plate and easily control the temperature.

Further, the casing according to the present invention can provide a robust structure as a hot plate unit, and the casing is not distorted even when a force is applied to the surface of the hot plate, so that the amount of warpage of the hot plate itself can be reduced. Ceramics have extremely good corrosion resistance to reactive gases and the like, and can be used with high durability in semiconductor manufacturing equipment. Therefore, the present invention can provide a hot plate unit having excellent heat uniformity and temperature controllability. further,
The casing according to the present invention has an advantage of having durability against a heat cycle.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view showing a hot plate unit according to an embodiment of the present invention.

FIG. 2 is an explanatory side sectional view showing a part of the hot plate unit according to the embodiment of the present invention;

FIG. 3 is an explanatory side sectional view showing a part of a hot plate unit according to another embodiment of the present invention.

FIG. 4 is an explanatory side sectional view showing a part of a hot plate unit according to another embodiment of the present invention.

FIG. 5 is an explanatory plan view (sectional view taken along the line AA in FIG. 6) showing a part of a hot plate unit according to another embodiment of the present invention.

FIG. 6 is an explanatory side sectional view showing a part of a hot plate unit according to another embodiment of the present invention.

FIGS. 7A and 7B are top explanatory views showing an electrostatic electrode according to another embodiment of the present invention.

[Description of Signs] 1. Hot plate unit, 2. Casing, 3. Hot plate, 10. Resistor

Continued on the front page F term (reference) 3K034 AA02 AA04 AA08 AA10 AA16 AA19 AA37 BB05 BB06 BB14 BC04 BC12 GA03 3K092 PP20 QA05 QB18 QB30 QB74 QB76 RF03 RF11 RF12 RF17 RF22 TT30 VV22

Claims (4)

[Claims] 1. A hot plate unit in which a hot plate made of a ceramic sintered body having a heating element is installed at an opening of a casing, wherein the casing is made of ceramic. 2. The hot plate unit according to claim 1, wherein a chuck top conductor layer is formed on a surface of said hot plate unit, and functions as a wafer prober. 3. The hot plate unit according to claim 1, wherein the hot plate unit has an electrostatic electrode inside and functions as an electrostatic chuck. 4. The hot plate unit according to claim 1, wherein the ceramic is at least one selected from the group consisting of machinable ceramics, quartz glass, and a composite of a ceramic fiber and an inorganic binder.