JP2002373769A - Hot plate unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot plate unit free of any risk of a heat insulation ring making deformation even if the ring has got a high temperature when the temperature of a ceramic substrate is to be raised and capable of maintaining the level of the ceramic substrate. SOLUTION: The hot plate unit is configured so that the ceramic substrate is fitted in the heat insulation ring installed on a supporting vessel and fixed thereto with the ring interposed, wherein the ring is provided with a through hole to admit insertion of a coupling member which fixes the ring to the supporting vessel, and a sleeve made of a resin having a higher softening point than the ring is fitted in the through hole, and the coupling member is inserted through the sleeve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot plate unit mainly used for manufacturing and testing semiconductors.

[0002]

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

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

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

Japanese Patent Application Laid-Open No. H11-40330 discloses that a substrate made of a nitride ceramic or a carbide ceramic having a high thermal conductivity and a high strength is used as a substrate, and the surface of a plate made of these ceramics is coated with a metal. There has been proposed a ceramic substrate provided with a resistance heating element formed by sintering particles.

FIG. 9 is a cross-sectional view schematically showing a hot plate unit in which a ceramic substrate having such a configuration is installed in a supporting container. In this hot plate unit 800, a disc-shaped ceramic substrate 11 having a resistance heating element 12 formed on a bottom surface 11b is fitted into a cylindrical heat insulating ring 88.
The external terminal 13 is connected via a solder layer (not shown) or the like.

A substrate receiving portion 20a for supporting the ceramic substrate 11 is integrally formed inside a lower portion of the heat insulating ring 88, has an L-shaped cross section, and is provided on a lower surface of the heat insulating ring 88. , Cylindrical container body 2 with bottom
0 is attached and fixed using the connecting member 22.

The connecting member 22 also has a function of fixing the holding metal fittings 24, and the holding metal fittings 24 allow the ceramic substrate 11 fitted in the heat insulating ring 88.
Are pressed and fixed to the substrate receiving portion 20a.

At the bottom of the supporting container 20, a refrigerant introducing pipe 19 is provided. Through the refrigerant introducing pipe 19, the refrigerant is introduced into the supporting container 20, and the refrigerant is introduced into the main body of the supporting container 20. It is discharged from the provided opening 20b,
At the time of cooling after heating, the ceramic substrate 11 is quickly cooled.

When power is supplied to the hot plate unit having such a configuration, the resistance heating element generates heat. As a result, an object to be heated such as the semiconductor wafer 29 mounted on the ceramic substrate 11 can be heated to a predetermined temperature. .

[0011]

However, since the connecting member 22 and the heat insulating ring 88 are in direct contact with each other in the hot plate unit having the above-described structure, when the temperature of the ceramic substrate 11 is increased. In addition, when the heat insulating ring 88 in contact with the ceramic substrate 11 has a temperature equal to or higher than its softening point, the heat insulating ring 88 is deformed with time, and as a result, the ceramic substrate 11 on the support container 20 is not fixed horizontally. There was something.

When the ceramic substrate 11 is not fixed horizontally, a difference occurs in the amount of light irradiation during the exposure process in the step of forming a conductor circuit on the semiconductor wafer 29 which is the object to be heated. Problems such as the inability to form a conductor circuit as set on the wafer 29 may occur.

Further, due to the deformation of the heat insulating ring 88,
Variations occur in the adhesion between the ceramic substrate 11 and the heat insulating ring 88, and
Due to the difference in the degree of heat dissipation to the substrate, the uniformity of the temperature of the heating surface of the ceramic substrate 11 may be reduced.

[0014]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a heat insulating ring for fixing a ceramic substrate is provided with a sleeve made of a resin having a softening point higher than that of the heat insulating ring. By inserting the connecting member into this sleeve and fixing the ceramic substrate to the support container, even when the ceramic substrate is heated to a high temperature when an object to be heated such as a semiconductor wafer is heated, the ceramic is They have found that the horizontality of the substrate can be maintained permanently, and have completed the present invention.

That is, in the hot plate unit of the present invention, a ceramic substrate is fitted into a heat insulating ring provided on a supporting container, and the ceramic substrate is fixed to the supporting container via the heat insulating ring. A plate unit, wherein the heat insulating ring has a through hole formed therein for inserting a connecting member for fixing the heat insulating ring to the support container, and the through hole has a softening point temperature lower than that of the heat insulating ring. A sleeve made of a high-resin resin is fitted, and the connecting member is inserted into the sleeve.

According to the hot plate unit, since the heat insulating ring for fixing the ceramic substrate is provided with the sleeve made of a resin having a softening point higher than that of the heat insulating ring, the temperature of the ceramic substrate may be high. Even so, the mechanical strength around the connecting member is maintained, and the horizontality of the ceramic substrate can be maintained permanently.

Thus, in the step of forming a conductor circuit on the semiconductor wafer to be heated, there is no difference in the light irradiation amount during the exposure processing, and the conductor circuit as set on the semiconductor wafer is formed. Can be formed.

Furthermore, since the heat insulating ring is not deformed, the adhesion between the ceramic substrate and the heat insulating ring does not vary, and the uniformity of the temperature of the heating surface of the ceramic substrate can be ensured.

Preferably, the sleeve is made of a polyimide resin. This is because the polyimide resin has a high softening point temperature and is excellent in heat resistance, and therefore does not deform even when the connecting member is heated to a high temperature. Also, it is extremely excellent in mechanical stability.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In a hot plate unit according to the present invention, a ceramic substrate is fitted into a heat insulating ring disposed on a support container, and the ceramic substrate is fixed to the support container via the heat insulating ring. In the hot plate unit, the heat insulating ring is formed with a through hole for inserting a connecting member for fixing the heat insulating ring to the support container, and the through hole is softer than the heat insulating ring. A sleeve made of a resin having a high point temperature is fitted, and the connecting member is inserted into the sleeve.

FIG. 1 is a sectional view schematically showing an example of the hot plate unit of the present invention, and FIG. 2 is a plan view schematically showing a ceramic heater which is a part of the hot plate unit shown in FIG. It is. FIG. 3 is a cross-sectional view schematically showing another example of the hot plate unit of the present invention.

The hot plate unit 100 has a disc-shaped ceramic substrate 11 having a resistance heating element 12 formed on the bottom surface thereof, and a bottomed cylindrical support container 20 for supporting the ceramic substrate 11 via a heat insulating ring 28. It is comprised including.

On the bottom surface of the disk-shaped ceramic substrate 11, a resistance heating element 12 is formed. The resistance heating elements 12 are, as shown in FIG. 2, formed on the outermost periphery of the ceramic substrate 11 in a circular arc pattern repeatedly formed so as to draw a part of a concentric circle.
Are arranged therein, and resistance heating elements 12e to 12g, which are concentric circular patterns partially cut away, are arranged therein.

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

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

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

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

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

An external terminal 13 is connected to an end of the resistance heating element 12 via a solder layer (not shown) or the like, and a socket 27 having a lead wire 26 is attached to the external terminal 13. The lead wire 26 is drawn out of the support container 20 and is connected to a power source (not shown).

A plurality of through holes 15 for inserting lifter pins (not shown) used for carrying the semiconductor wafer 29 and the like are formed in a portion near the center of the ceramic substrate 11, and a support container 20 is provided. A through hole communicating with these is also formed at the bottom of the guide tube.
The semiconductor wafer 29 can be transferred by raising and lowering the lifter pins.

Further, a plurality of recesses are formed on the heating surface of the ceramic substrate 11, and support pins 31 are provided in the recesses. The semiconductor wafer 29, which is the object to be heated, is It can be supported and heated with a certain distance from the heating surface. The hot plate unit 100 of the present invention
In the above, the concave portion and the support pin 31 may be provided or may not be provided.

A bottomed hole 14 for inserting a temperature measuring element 17 such as a thermocouple is formed in a bottom surface 11 b of the ceramic substrate 11, and a wiring 16 is led out from the temperature measuring element 17. It has been pulled out.

As shown in FIG. 1, an intermediate bottom plate 33 is attached to the support container 20. The support container 20 is provided with a refrigerant introduction pipe 19 so that a forced cooling refrigerant or the like can be introduced into the support container 20 and the introduced forced cooling refrigerant or the like. Through holes 20b are formed for discharging the water.

The middle bottom plate 33 is provided for the purpose of fixing wiring and the like and for heat shielding. The middle bottom plate 33 has a refrigerant introduction pipe 19 fixed to the bottom of the support container 20 and a lifter pin (not shown). A through-hole is formed so as not to obstruct the guide tube 18 and the like for protecting (not shown). In the present invention, the midsole plate 33 is not essential. That is, even if the midsole plate 33 is not formed in the support container 20, it functions as the hot plate unit of the present invention.

The ceramic substrate 11 is fitted into a cylindrical heat insulating ring 28, and the heat insulating ring 28
A substrate receiving portion 20a for supporting the ceramic substrate 11 is integrally formed on the inner side of the lower portion of the base member, and has an L-shaped cross section. The container 20 is attached and fixed using a connecting member 22.

The hot plate unit 1 of the present invention
In 00, the sleeve 25 is fitted into a through hole formed for allowing the connecting member 22 to pass through the heat insulating ring 28, and the ceramic substrate 11 is inserted into the sleeve 25 with the connecting member 22 inserted. It is fixed to a heat insulating ring 28.

The material of the sleeve 25 is not particularly limited. For example, it is desirable that the sleeve 25 be made of at least one resin selected from a polyimide resin, a fluororesin, and a benzimidazole resin, or a fiber-reinforced resin. . Examples of the fiber-reinforced resin include a resin in which glass fiber is dispersed.
This is because the fiber reinforced resin is not easily softened even when the temperature is raised.
Of these, polyimide resins are most desirable. This is because the polyimide resin has a high softening point temperature and excellent heat resistance, and therefore does not deform even when the ceramic substrate 11 is at a high temperature. In addition, even when a long period of time has elapsed or when the temperature is high, it is mechanically stable.

The material of the heat insulating ring 28 is not particularly limited. For example, the heat insulating ring 28 may be made of at least one resin selected from a polyimide resin, a fluorine resin, a benzimidazole resin, or a fiber-reinforced resin. desirable. Examples of the fiber-reinforced resin include a resin in which glass fiber is dispersed. This is because the fiber reinforced resin is not easily softened even when the temperature is raised.

These resins are the same as those used for the sleeve 25, but the heat insulating ring 28
Requires adhesion to the ceramic substrate 11,
Moderate plasticity is required. Therefore, the insulating ring 28
Is mechanically weaker than the sleeve 25.

The connecting member 22 also has a function of fixing the holding metal fitting 24, and the holding metal fitting 24 allows the ceramic substrate 11 fitted to the heat insulating ring 28.
Are pressed and fixed to the substrate receiving portion 20a.
Therefore, the ceramic substrate 11 is supported and fixed inside the support container 20 via the heat insulating ring 28. The ceramic substrate 11 and the bottom of the support container 20 are supported and fixed so as to be substantially parallel.

The hot plate unit 100 includes:
A control device (not shown) containing a control device, a power supply, and the like is provided below the hot plate unit. The lead wire 19 is connected to a control device, a power supply, and the like in the control device and is energized. Function as

On the other hand, as shown in FIG. 3, the hot plate unit 200 may be provided with a projection 21 between the heat insulating ring 28 and the ceramic substrate 11. The ceramic substrate 11 having the above configuration is placed on the projection 21,
In the vicinity of the protrusion 21, a connecting member 22 such as a bolt penetrating the ceramic substrate 11, the holding member 24, and the substrate receiving portion 20a is installed, and the ceramic substrate 11 is pressed against the protrusion 21 by the holding member 24. Fixed.

The contact area between the ceramic substrate 11 and the projection 21 is extremely small, the amount of heat transferred through the holding metal 24 is small, and the other portion around the ceramic substrate 11 is surrounded by an air layer. The heat radiation amount of the ceramic substrate 11 can be kept small, and as a result, the temperature of the ceramic substrate 11 can be quickly raised, and the temperature of the heating surface of the ceramic substrate 11 can be made more uniform.

Also, in the hot plate unit 200, similarly to the hot plate unit 100 shown in FIG. 1, the sleeve 25 is fitted into a through hole formed for inserting the connecting member 22 into the heat insulating ring 38. The ceramic substrate 11 is fixed to the heat insulating ring 38 with the connecting member 22 inserted into the sleeve 25.

FIG. 4 is a cross-sectional view schematically showing another embodiment of the hot plate unit of the present invention, and FIG.
FIG. 6 is a plan view of a ceramic heater which is a part of the hot plate unit shown in FIG. 4, and FIG. 6 is a cross-sectional view schematically showing still another embodiment of the hot plate unit.

In this hot plate unit 500,
The ceramic substrate 51 is formed in the shape of a disc. Inside the ceramic substrate 51, as shown in FIG. 5, the outermost periphery of the ceramic substrate 51 is formed by a repetitive pattern of bending lines divided in the circumferential direction. Resistance heating elements 52a to 52
h are formed, and on the inner periphery thereof, resistance heating elements 52i to 521 formed of a similar repetitive pattern of bent lines are formed. Further, concentric resistance heating elements 52m to 52p are formed on the inner periphery thereof.

A through hole 72 is formed immediately below the end of the resistance heating element 52, and a blind hole (not shown) for exposing the through hole 72 is formed on the bottom surface 51b.
The external terminal 53 is inserted into the blind hole, and is joined with a brazing material (not shown) or the like. And the external terminal 5
A socket 55 having a lead wire 66 is attached to 3, and this lead wire 66 is connected to a power supply (not shown).

In this hot plate unit 500,
Since the configuration other than the resistance heating element 52 and the peripheral portion of the resistance heating element 52 is the same as that of the hot plate unit shown in FIG. 1, the detailed description is omitted here.

The hot plate unit 60 shown in FIG.
Also in the case of 0, the protrusion 61 may be provided between the heat insulating ring 68 and the ceramic substrate 51.

The ceramic substrate 51 having the above-described structure is mounted on the projection 61. In the vicinity of the projection 61, the ceramic substrate 51, the holding member 64, and the substrate receiving portion 60 are provided.
A connecting member 62 such as a bolt penetrating through a is provided, and the ceramic substrate 51 is pressed against the protrusion 61 by a holding metal 64 and fixed to the support container 60.

Also, in the hot plate unit 600, similarly to the hot plate unit 500 shown in FIG. 4, the sleeve 65 is fitted into a through hole formed for inserting the connecting member 62 into the heat insulating ring 78. The ceramic substrate 51 is fixed to the heat insulating ring 78 with the connecting member 62 inserted through the sleeve 65.

The operating temperature range of the hot plate unit of the present invention having the sleeve in the heat insulating ring as described above is not particularly limited.
It can be used in the middle temperature range of 00 to 400 ° C and the high temperature range of 400 to 800 ° C. Above all, 400
It is desirable to use in a high temperature range of -800 ° C. This is because, in the above-mentioned region, the temperature of the connecting member connected to the ceramic substrate also becomes high, and the configuration of the present invention functions effectively.

Next, the ceramic substrate and the like constituting the hot plate unit of the present invention will be described in more detail.

In the present invention, the pattern of the resistance heating element formed on the ceramic substrate is not particularly limited as long as it is divided into a plurality of circuits.
For example, as shown in FIG. 2, a pattern using a combination of a circular arc repetition pattern and a concentric pattern, a bending line repetition pattern, a spiral pattern, an eccentric pattern, a concentric pattern, and the like can be given. Further, these patterns may be formed alone, or may be formed by arbitrarily combining these patterns.

It is desirable that the resistance heating element is divided into at least two or more circuits. This is because, by dividing the circuit, the amount of heat generated can be changed by controlling the power supplied to each circuit, and the temperature of the heating surface of the semiconductor wafer can be adjusted.

The thickness of the resistance heating element is preferably 1 to 30 μm, more preferably 1 to 10 μm. Further, the width of the resistance heating element is preferably 0.1 to 20 mm, and 0.1 to 5 mm.
Is more preferred. Although the resistance value of the resistance heating element can be varied depending on its width or thickness, the above range is most practical.

The resistance heating element may have a rectangular or elliptical cross section, but is preferably flat. This is because the flat surface is more likely to dissipate heat toward the heating surface, so that the temperature distribution on the heating surface is less likely to occur. The aspect ratio of the cross section (the width of the resistance heating element / the thickness of the resistance heating element) is 10 to 50.
00 is desirable. By adjusting to this range, the resistance value of the resistance heating element can be increased, and the uniformity of the temperature of the heating surface can be ensured.

When the thickness of the resistance heating element is constant, if the aspect ratio is smaller than the above range, the amount of heat transmission in the direction of the heating surface of the ceramic substrate is reduced, and the heat distribution approximates the pattern of the resistance heating element. If the aspect ratio is too large, on the other hand, if the aspect ratio is too large, the temperature immediately above the center of the resistance heating element will be high, and eventually, a heat distribution similar to the pattern of the resistance heating element will occur on the heating surface. Would. Therefore, considering the temperature distribution, the aspect ratio of the cross section is 1
It is preferably from 0 to 5000.

Regarding the variation of the resistance value of the resistance heating element, the variation of the resistance value with respect to the average resistance value is preferably 5% or less, more preferably 1%. It is desirable that the resistance heating element of the present invention is divided into a plurality of circuits. However, by reducing the variation of the resistance value in this way, the number of divisions of the resistance heating element can be reduced and the temperature can be easily controlled. Can be. Further, it is possible to make the temperature of the heating surface uniform during the transition of the temperature rise.

Usually, such a resistance heating element is formed by applying a conductive paste containing metal particles or conductive ceramic particles for securing conductivity on a ceramic substrate and firing the paste. Note that the resistance heating element may be formed using a physical vapor deposition method such as a plating method or sputtering. In the case of plating, a resistive heating element can be formed by forming a plating resist, and in the case of sputtering or the like, by performing selective etching.

The conductive paste is not particularly limited, but preferably contains not only the metal particles or the conductive ceramic but also a resin, a solvent, a thickener and the like.

As the metal particles, for example, noble metals (gold, silver, platinum, palladium), lead, tungsten, molybdenum, nickel and the like are preferable. These may be used alone or in combination of two or more. This is because these metals are relatively hard to oxidize and have a resistance value sufficient to generate heat. Examples of the conductive ceramic include carbides of tungsten and molybdenum. These may be used alone or in combination of two or more.

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

As the conductor paste, it is desirable to use a material obtained by adding metal oxide to metal particles, apply the metal oxide on a ceramic substrate, and then sinter the metal particles and the metal oxide. . By sintering the metal oxide together with the metal particles in this manner, the ceramic substrate, such as a nitride ceramic, and the metal particles can be more closely adhered to each other.

It is not clear why the mixing with the metal oxide improves the adhesion to the nitride ceramic or the like, but the surface of the metal particles or the surface of the nitride ceramic is slightly oxidized to form an oxide film. It is considered that these oxide films are sintered and integrated via the metal oxide, and the metal particles and the nitride ceramics or the like adhere to each other. Further, when the ceramic constituting the ceramic substrate is an oxide ceramic, the surface is naturally made of an oxide, so that a conductor layer having excellent adhesion is formed.

As the metal oxide, for example,
Lead, zinc oxide, silica, boron oxide (B ₂O₃), Al
Selected from the group consisting of Mina, Yttria and Titania
At least one is preferred. These oxides have resistance
Nitriding of metal particles without increasing the resistance of the heating element
Can improve the adhesion to ceramics etc.
It is.

The ratio of the above-mentioned lead oxide, zinc oxide, silica, boron oxide (B ₂ O ₃ ), alumina, yttria, and titania is as follows: 1-10, silica 1-30, boron oxide 5-50, zinc oxide 20-70, alumina 1
-10, yttria 1-50, titania 1-50, and the total is preferably adjusted within a range not exceeding 100 parts by weight. By adjusting the amounts of these oxides within these ranges, the adhesion to nitride ceramics and the like can be particularly improved. The amount of the metal oxide added to the metal particles is preferably 0.1% by weight or more and less than 10% by weight.

The area resistivity when the resistance heating element is formed using the conductor paste having such a configuration is 0.1%.
mΩ / □ to 10Ω / □ is preferred. Area resistivity is 0.1
When the resistivity is less than mΩ / □, the resistivity is too small and the calorific value is too small to function as a resistance heating element. On the other hand, when the area resistivity exceeds 10 Ω / □, the calorific value with respect to the applied voltage Is too large to control the amount of heat generated by the resistance heating element. In terms of controlling the heat generation,
The area resistivity of the resistance heating element is more preferably 1 to 50 mΩ / □. However, when the sheet resistivity is increased, the pattern width (cross-sectional area) can be increased, and the problem of disconnection hardly occurs. Therefore, in some cases, it is preferable to set the resistance to 50 mΩ / □ or more.

The metal used for forming the metal coating layer is not particularly limited as long as it is a non-oxidizing metal, and specific examples include gold, silver, palladium, platinum, nickel and the like. . These may be used alone or in combination of two or more. Of these, nickel is preferred. Further, 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, but nickel prevents heat diffusion of the solder. Examples of the connection terminal include those made of Kovar.

The material of the ceramic substrate constituting the hot plate 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, for example, aluminum nitride, silicon nitride, boron nitride, titanium nitride and the like. Further, as the carbide ceramic, metal carbide ceramic,
For example, silicon carbide, zirconium carbide, titanium carbide,
Examples include tantalum carbide and tungsten 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.

[0073] Among these ceramics, nitride ceramics and carbide ceramics are more preferable than oxide ceramics. This is because the thermal conductivity is high. Further, among nitride ceramics, aluminum nitride is most preferable. This is because the thermal conductivity is the highest at 180 W / m · K.

Further, the ceramic material may contain a sintering aid. As the sintering aid, for example,
Examples thereof include alkali metal oxides, alkaline earth metal oxides, and rare earth oxides. Among these sintering aids,
_{CaO, Y 2 O 3, Na} 2 O, Li 2 O, Rb 2 O are preferred. Their content is 0.1 to 20% by weight.
Is preferred. Further, it may contain alumina.

The above ceramic substrate has a brightness of JIS Z
It is desirable that the value based on the rule of 8721 is N4 or less. This is because a material having such brightness is excellent in radiant heat and concealing property. Further, such a ceramic substrate can accurately measure the surface temperature by using a thermoviewer.

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

The ceramic substrate having such characteristics is characterized in that carbon is added to the ceramic substrate in an amount of 100 to 5000 p.
pm. There are two types of carbon, amorphous and crystalline.Amorphous carbon can suppress a decrease in volume resistivity of a ceramic substrate at a high temperature. Since the decrease in thermal conductivity at high temperatures can be suppressed, the type of carbon can be appropriately selected according to the purpose of the substrate to be manufactured.

The amorphous carbon is, for example, C, H, O
Hydrocarbons, preferably saccharides, can be obtained by calcining in air, and graphite powder can be used as the crystalline carbon.
In addition, carbon can be obtained by thermally decomposing the acrylic resin under an inert atmosphere and then heating and pressurizing. However, by changing the acid value of the acrylic resin, it is possible to obtain a crystalline (non-crystalline) material. Can be adjusted.

The ceramic substrate used in the ceramic heater has a disk shape and a diameter of 200 mm.
mm is desirable. This is because a substrate having such a large diameter can mount a large-diameter semiconductor wafer, and the configuration of the present invention functions effectively. The diameter of the ceramic substrate is particularly 12 inches (30 inches).
0 mm) or more. This is because it will become the mainstream of next-generation semiconductor wafers.

The thickness of the ceramic substrate is 25
mm or less. This is because if the thickness of the ceramic substrate exceeds 25 mm, the temperature followability decreases. Further, its thickness is desirably 0.5 mm or more. When the thickness is smaller than 0.5 mm, the strength of the ceramic substrate itself is reduced, so that the ceramic substrate is easily broken. More preferably, it is more than 1.5 and 5 mm or less. When the thickness is more than 5 mm, the heat is difficult to propagate, and the heating efficiency tends to decrease. On the other hand, when the thickness is less than 1.5 mm, the heat propagating in the ceramic substrate is not sufficiently diffused, so that the temperature variation on the heating surface is caused. May occur, and the strength of the ceramic substrate may be reduced to cause breakage.

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

The insulating layer is preferably made of an oxide ceramic, specifically, silica, alumina, mullite,
Cordierite, beryllia and the like can be used.
Such an insulating layer may be formed by spin-coating a sol solution obtained by hydrolyzing and polymerizing an alkoxide on a ceramic substrate, followed by drying and firing, or by sputtering, CVD, or the like. Further, an oxide layer may be provided by oxidizing the surface of the ceramic substrate.

The thickness of the insulating layer is desirably 0.1 to 1000 μm. If the thickness is less than 0.1 μm, the insulating property cannot be ensured. If the thickness exceeds 1000 μm, the thermal conductivity from the resistance heating element to the ceramic substrate is impaired. Further, it is desirable that the volume resistivity of the insulating layer is 10 times or more (same measurement temperature) as the volume resistivity of the ceramic substrate. If it is less than 10 times, a short circuit cannot be prevented.

In the ceramic heater constituting the hot plate unit of the present invention, as shown in FIG. 1, a bottomed hole 14 is formed on the ceramic substrate from the side opposite to the heating surface on which the object to be heated is placed toward the heating surface. It is preferable that the bottom of the bottomed hole 14 is formed closer to the heating surface than the resistance heating element 12, and the bottomed hole 14 is provided with a temperature measuring element 17 such as a thermocouple. Further, the distance between the bottom of the bottomed hole 14 and the heating surface of the ceramic heater 1 is desirably 0.1 mm to 1/2 of the thickness of the ceramic substrate. As a result, the temperature measurement location is smaller than the resistance heating element 12 in the ceramic substrate 1.
This is because the temperature becomes closer to the heating surface of No. 1 and the temperature of the semiconductor wafer can be measured more accurately.

If the distance between the bottom of the bottomed hole 14 and the heating surface of the ceramic substrate 11 is less than 0.1 mm, heat is radiated,
A temperature distribution is formed on the heating surface of the ceramic substrate 11. If the thickness exceeds の of the thickness, the temperature distribution of the resistance heating element becomes more susceptible and the temperature cannot be controlled. Is formed.

The diameter of the bottomed hole 14 is 0.3 mm to 5 mm.
It is desirable that This is because if it is too large, the heat radiation will be large, and if it is too small, the workability will be reduced and the distance to the heating surface of the ceramic heater 1 cannot be equalized.

It is desirable that a plurality of the bottomed holes 14 are arranged symmetrically with respect to the center of the ceramic substrate 11 and form a cross. This is because the temperature of the entire heating surface can be measured.

As the temperature measuring element, for example, a thermocouple,
Platinum resistance thermometers, thermistors and the like can be mentioned. As the thermocouple, for example, JIS-C-1602 (1
980), K type, R type, B type, S type
Type, E-type, J-type, and T-type thermocouples, and among them, a K-type thermocouple is preferable.

It is desirable that the size of the junction of the thermocouple is equal to or larger than the diameter of the strand, and is 0.5 mm or less. This is because, if the junction is large, the heat capacity increases and the responsiveness decreases. It is difficult to make the diameter smaller than the diameter of the strand.

The temperature measuring element may be adhered to the bottom of the bottomed hole 14 using gold brazing, silver brazing, or the like.
And then sealed with a heat-resistant resin, or both may be used in combination. Examples of the heat-resistant resin include a thermosetting resin, particularly an epoxy resin, a polyimide resin, a bismaleimide-triazine resin, and the like. These resins may be used alone or in combination of two or more.

As the above-mentioned gold solder, 37-80.5% by weight Au-63-19.5% by weight Cu alloy, 81.5-8%
2.5% by weight: Au-18.5 to 17.5% by weight: Ni
At least one selected from alloys is desirable. These are because the melting temperature is 900 ° C. or higher and it is difficult to melt even in a high temperature region. As a silver solder, for example, Ag
-A Cu-based material can be used.

Further, a semiconductor wafer or the like to be heated is
Since the semiconductor wafer is held at a certain distance from the heating surface of the ceramic heater so as to prevent temperature variations due to the influence of the temperature distribution on the heating surface of the ceramic heater, as shown in FIG. Support pins 31 for supporting semiconductor wafer 29, and support pins 31
It is desirable to form a concave portion provided with. It is also possible to form a through-hole instead of the concave portion and insert and fix the support pin.

The height at which the support pins project from the heating surface of the ceramic heater is 5 to 5000 μm, that is, the object to be heated is 5 to 5 μm from the heating surface of the ceramic substrate.
It is desirable to hold them in a state of being separated by 000 μm. 5
If it is less than μm, the temperature of the semiconductor wafer will be uneven due to the influence of the temperature distribution of the ceramic substrate, and if it exceeds 5000 μm, the temperature of the semiconductor wafer will not easily rise, It is because it becomes. The object to be heated and the heating surface of the ceramic substrate are 5
It is more preferable that the distance is about 500 μm.
It is more desirable to be separated by 0 μm.

The above-mentioned supporting container is easy to process and has excellent mechanical properties and can secure the strength of the entire supporting container. Therefore, SUS, aluminum, inconel (a nickel-based alloy containing 16% of chromium and 7% of iron) It is desirable to be made of a metal such as In addition, when the outer frame portion and the bottom portion of the support container are not integrated, the bottom portion includes
In order to have excellent heat shielding properties, for example, a heat-resistant resin, a ceramic plate, a composite plate in which heat-resistant organic fibers or inorganic fibers are blended, etc. Can also be used.

The hot plate unit of the present invention is an apparatus mainly used for manufacturing a semiconductor or inspecting a semiconductor, in which a ceramic substrate provided only with a resistance heating element is installed in a supporting container. When an electrostatic electrode is provided inside the ceramic substrate, it functions as an electrostatic chuck, a conductor layer is provided on the surface of the ceramic substrate, and when a guard electrode or a ground electrode is provided inside the ceramic substrate, Functions as a wafer prober.

Next, the hot plate unit 1 of the present invention
An example of the manufacturing method of No. 00 will be described based on the cross-sectional views shown in FIGS.

(1) Step of Manufacturing Ceramic Substrate The above-mentioned ceramic powder such as nitride such as aluminum nitride or silicon carbide is added to yttria (Y ₂ O ₃ ) if necessary.
Sintering aids and B _{4 C} or the like, Na, compounds containing Ca, after blended with a binder or the like to prepare a slurry, the slurry was granulated by a method such as spray drying, the granules and the like in a mold It is molded into a plate shape by putting and pressing,
A green form is produced. Next, the formed body is heated, fired and sintered to produce a ceramic plate. After that, the ceramic substrate 11 is manufactured by processing into a predetermined shape, but may be a shape that can be used as it is after firing.

By performing heating and firing while applying pressure, it is possible to manufacture a ceramic substrate 11 having no pores. Heating and firing may be performed at a sintering temperature or higher.
0 to 2500 ° C. In oxide ceramics,
1500 ° C to 2000 ° C.

Next, as necessary, a portion serving as a through hole 15 for inserting a lifter pin for supporting a semiconductor wafer and a bottomed hole 14 for embedding a temperature measuring element 17 such as a thermocouple are formed in the ceramic substrate 11. Is formed. (See FIG. 7A).

(2) Step of Printing Conductive Paste on Ceramic Substrate The conductive paste is a highly viscous fluid composed of metal particles composed of two or more kinds of noble metals, resins, and solvents. This conductor paste is formed by screen printing or the like to form a conductor paste layer serving as a resistance heating element pattern.

At this time, a conductor paste layer is formed on the outermost periphery of the ceramic substrate 11 so as to form at least two or more circuits divided in the circumferential direction, and the inside of the conductor paste layer printed on the outermost periphery is formed. Then, it is desirable to form a conductor paste layer that becomes another circuit. The pattern formed on the outermost periphery of the ceramic substrate as the resistance heating element pattern includes, for example, a repetition pattern of arcs, a repetition pattern of bending lines, and the like. The pattern formed therein may be, for example, a concentric pattern. Further, it is desirable that the conductive paste layer is formed so that the cross section of the resistance heating element 12 after firing is square and flat.

(3) Firing of Conductive Paste The conductive paste layer printed on the bottom surface of the ceramic substrate 11 is heated and fired to remove the resin and the solvent, sinter the metal particles, and baked on the bottom surface of the ceramic substrate 11.
The resistance heating element 12 is formed (see FIG. 7B). The temperature of the heating and firing is preferably from 500 to 1000C. If the above-mentioned oxide is added to the conductor paste, metal particles,
Since the ceramic substrate and the oxide are sintered and integrated, the adhesion between the resistance heating element and the ceramic substrate is improved.

(4) Formation of Metal Coating Layer A metal coating layer 120 is provided on the surface of the resistance heating element 12 (see FIG. 7C). The metal coating layer 120 can be formed by electrolytic plating, electroless plating, sputtering, or the like. However, considering mass productivity, electroless plating is optimal.

(5) Attachment of Terminals and the like Terminals (external terminals 13) for connection to a power supply are attached to the ends of the pattern of the resistance heating element 12 by soldering. In addition, the temperature measuring element 1 such as a thermocouple or the like with
7 is fixed and sealed with a heat-resistant resin such as polyimide to complete the manufacture of the ceramic heater 10 (FIG. 7).
(D)).

(6) Preparation of Support Container Next, a support container 20 as shown in FIG. 1 is prepared. It is desirable that the support container 20 has a cylindrical shape with a bottom. At the bottom of the support container 20, a refrigerant introduction pipe 19 for supplying a refrigerant for forced cooling can be provided, and a through hole 20b for discharging the supplied refrigerant can be formed.

(7) Assembly of Hot Plate Unit After this, the obtained ceramic heater 10 is
1a through a heat insulation ring 28 having a sleeve 25 therein as shown in FIG.
The ceramic substrate 11 is fixed to the support container 20 by a connecting member 22 through which Oa is inserted. Also, as shown in FIG.
The protrusion 2 is provided between the ceramic substrate 11 and the heat insulating ring 38.
1 can be provided to reduce the contact area between the ceramic substrate 11 and the heat insulating ring 38. Then, by providing wiring from the temperature measuring element 17 and the resistance heating element 12 and drawing out the lead wire 26 from the bottom of the support container 20,
The manufacture of the hot plate unit 100 is completed.

Next, the hot plate unit 5 of the present invention
An example of the manufacturing method of No. 00 will be described with reference to the cross-sectional views shown in FIGS.

(1) Preparation of Green Sheet First, a green sheet 70 is obtained by mixing a ceramic powder such as a nitride ceramic or a carbide ceramic with a binder and a solvent. As ceramic powder, for example,
Aluminum nitride powder, silicon nitride powder, or the like can be used. Further, a sintering aid such as yttria may be added.

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 by a doctor blade method to produce a green sheet 70. The thickness of the green sheet 70 is preferably about 0.1 to 5 mm.
In the green sheet 70, a through hole is formed at a portion where a through hole is formed by punching or the like. In addition,
In the green sheet 70, it is also possible to form a through-hole at a portion to be the through-hole 55.

Next, a conductive paste is filled into the through holes of the green sheet 70 to obtain a filling layer 720, and then a conductive paste serving as a resistance heating element is printed on the green sheet 70. The printing is performed so as to obtain a desired aspect ratio in consideration of the shrinkage ratio of the green sheet 70, thereby obtaining the conductive paste layer 520. The conductor paste is a high-viscosity fluid containing conductive ceramics, metal particles, and the like.

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

The average particle size of the conductive ceramic particles and metal particles is preferably 0.1 to 5 μm. This is because it is difficult to print the conductive paste when these particles are too large or too small. As such a paste, 85 to 97 parts by weight of metal particles or conductive ceramic particles, 1.5 to 10 parts by weight of at least one binder selected from acrylic, ethyl cellulose, butyl cellosolve and polyvinyl alcohol, α-terpineol, glycol A paste for a conductor prepared by mixing 1.5 to 10 parts by weight of at least one solvent selected from ethyl alcohol and butanol is most suitable.

(2) Production of Green Sheet Laminate Next, as shown in FIG. 8A, a green sheet 70 having a filling layer 720 and a conductor paste layer 520, and a filling layer 720 and a conductor paste layer 520 are provided. And a green sheet 70 not to be laminated. Laminating the green sheet 70 without the filling layer 720 and the conductive paste layer 520 on the resistance heating element forming side exposes the end face of the through hole and oxidizes during firing of the resistance heating element formation. This is to prevent that. 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 hardly oxidizable metal such as nickel, and more preferably, to coat with Au-Ni gold solder. Is also good.

(3) Firing the laminate Next, as shown in FIG. 8B, the laminate is heated and pressed to form a green sheet laminate. Thereafter, the green sheet and the conductive paste are sintered.
The temperature at the time of firing is 1700 to 2000 ° C, and the pressure at the time of firing is 10 to 20 MPa (100 to 200 kg /
cm ²⁾ is preferred. These heating and pressurizing are performed under an inert gas atmosphere. As the inert gas, argon, nitrogen, or the like can be used. In this firing step, the through holes 72, the resistance heating elements 52, and the like are formed.

The obtained ceramic substrate 51 is provided with a through hole 55 for inserting a lifter pin, a bottomed hole 54 for inserting a temperature measuring element, a blind hole 57 for inserting an external terminal 53, and the like. (FIG. 8 (c)). The through-hole 55, the bottomed hole 54, and the blind hole 57 can be formed by performing blast processing such as drilling or sand blasting after surface polishing.

(4) Attachment of Terminals and the Like Next, the external terminals 53 are connected to the through holes 72 exposed from the blind holes 57 using gold brazing or the like (FIG. 8D). Further, although not shown, for example, a socket having a conductive wire is detachably attached to the external terminal 53. The heating temperature is preferably 90 to 450 ° C. in the case of soldering, and 900 to 1100 ° C. in the case of processing with a brazing material.
Is preferred. Further, a thermocouple or the like as a temperature measuring element is sealed with a heat-resistant resin to form a ceramic heater 50.

Further, a temperature measuring element 57 such as a thermocouple is inserted into a bottomed hole 54 provided on the bottom surface of the ceramic substrate 51 and fixed with a heat-resistant insulating member such as a silicone resin. Complete the production of

(5) Preparation of Support Container Next, a support container 60 as shown in FIG. 4 is prepared. The support container 60 has a cylindrical shape with a bottom, and it is desirable that the outer frame portion and the bottom portion are formed integrally. At the bottom of the support container 60, a coolant introduction pipe 59 for supplying a coolant for forced cooling can be provided, and a through hole 60b for discharging the supplied coolant can be formed.

(6) Assembly of Hot Plate Unit After this, the obtained ceramic heater 50 is placed in the substrate receiving portion 6.
0a through a heat insulating ring 68 having a sleeve 65 therein as shown in FIG.
The ceramic substrate 51 is fixed to the support container 60 by a connecting member 62 through which Oa is inserted. Also, as shown in FIG.
The protrusion 6 is provided between the ceramic substrate 51 and the heat insulating ring 78.
1, the contact area between the ceramic substrate 51 and the heat insulating ring 78 can be reduced. Then, by providing wiring from the temperature measuring element 57 and the resistance heating element 52 and drawing out the lead wire 66 from the bottom of the support container 60,
The manufacture of the hot plate unit 500 is completed. An electrostatic chuck may be provided by providing a resistance heating element on the surface or inside the ceramic substrate and providing an electrostatic electrode inside the ceramic substrate. In the ceramic heater of the present invention, an electrostatic chuck may be provided by providing an electrostatic electrode, or a chuck top plate for a wafer prober may be provided by providing a chaptop conductor layer.

Although the hot plate unit has been described above, an electrostatic chuck can be manufactured by providing an electrostatic electrode inside a ceramic substrate, and a chuck top conductor layer is provided on a heating surface to provide a chuck top. By providing a guard electrode and a ground electrode inside, a wafer prober can be manufactured.

When electrodes are provided inside the ceramic substrate, a conductor paste layer may be formed on a green sheet in a pattern such as an electrostatic electrode or a guard electrode, and may be laminated and fired. In the case where a conductor layer is formed on the surface of the ceramic substrate, the conductor layer may be formed by using a sputtering method or a plating method after manufacturing the ceramic substrate. At this time, the sputtering method and the plating method may be used in combination.

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

EXAMPLES (Example 1) Production of a hot plate unit (see FIGS. 1 and 7) (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1 μm), yttrium oxide (Y ₂ O)
₃ : A composition comprising 4 parts by weight of yttria, an average particle diameter of 0.4 μm), 12 parts by weight of an acrylic resin binder and alcohol was spray-dried to prepare a granular powder.

(2) Next, the granulated powder was put in a mold and formed into a flat plate to obtain a formed product (green).

(3) The formed product after the processing is hot pressed at a temperature of 1800 ° C. and a pressure of 20 MPa.
An aluminum nitride sintered body having a thickness of 3 mm was obtained. next,
A disk having a diameter of 210 mm was cut out from the plate, and the surface was polished with a diamond paste having an average particle diameter of 1 μm, and the surface of the contact portion was Rm according to JIS R0601.
ax = 2 μm was used as a ceramic plate (ceramic substrate 11). Next, a drilling process is performed on the plate-shaped body, and a through hole 15 for inserting a lifter pin for transporting a semiconductor wafer and a bottomed hole for embedding a thermocouple (diameter: 1.1 mm, depth: 2 mm) 14 was formed (FIG. 7).
(A)).

(4) Ceramic substrate 1 obtained in (3) above
A conductor paste was printed on the bottom surface of the substrate 1 by screen printing. The printing pattern was a pattern of a combination of concentric circles and arcs as shown in FIG. As the conductive paste, Solvest PS60 manufactured by Tokuri Kagaku Kenkyusho, which is used for forming through holes in printed wiring boards, is used.
3D 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.

(5) 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 the sintered body to form a resistance heating element. The silver resistance heating element 12 has a thickness of 5 μm, a width of 2.4 mm, and a sheet resistivity of 7, near the terminals.
It was 7 mΩ / □ (FIG. 7 (b)).

(6) Next, nickel sulfate 80 g / l, sodium hypophosphite 24 g / l, sodium acetate 12 g
/ L, an aqueous solution containing boric acid 8 g / l and ammonium chloride 6 g / l in an electroless nickel plating bath (5).
Was immersed to deposit a metal coating layer 120 (nickel layer) having a thickness of 1 μm on the surface of the silver resistance heating element 12 (FIG. 7C).

(7) A silver-lead solder paste (manufactured by Tanaka Kikinzoku Co., Ltd.) was printed on the end of the resistance heating element 12 by screen printing to secure a connection with a power source to form a solder layer. Next, the external terminal 13 having a T-shaped cross section was placed on the solder layer, and the external terminal 13 was heated and reflowed at 420 ° C., and the external terminal 13 was attached to the end of the resistance heating element via the solder layer 120 (FIG. 7 (d)).

(8) A thermocouple for controlling temperature is provided in the bottomed hole 1
4 and filled with a polyimide resin and cured at 190 ° C. for 2 hours to obtain a ceramic substrate 11 having a resistance heating element 12 on the bottom surface 11b.

(9) After this, the ceramic substrate 11 is
Support container 20 having substrate receiving portion 20a as shown in FIG.
1 through a heat insulating ring 28 having a sleeve 25 therein as shown in FIG. 1, and a connecting member 2 inserted through the holding member 24, the sleeve 25 and the substrate receiving portion 20a.
In 2, the ceramic substrate 11 was fixed to the support container 20.
Further, the lead wire 26 extending from the external terminal 13 was pulled out from the through hole of the support container 20 to complete the manufacture of the hot plate unit 100.

Example 2 Production of Hot Plate Unit (See FIGS. 4 and 8) (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size: 1.1 μm), yttrium oxide (Y
₂ O ₃ : yttria, average particle size: 0.4 μm) 4 parts by weight, 11.5 parts by weight of an acrylic binder, 0.5 parts by weight of a dispersant, and a paste obtained by mixing 53 parts by weight of alcohol composed of 1-butanol and ethanol Was formed by a doctor blade method to produce a green sheet 70 having a thickness of 0.47 mm.

(2) Next, this green sheet 70
After drying at 0 ° C. for 5 hours, a through hole or the like serving as a through hole 72 was formed by punching.

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

Tungsten particles 10 having an average particle size of 3 μm
A conductive paste B was prepared by mixing 0 parts by weight, 1.9 parts by weight of an acrylic binder, 3.7 parts by weight of an α-terpineol solvent, and 0.2 parts by weight of a dispersant. This conductor paste A was printed on the green sheet by screen printing to form a conductor paste layer 520 for the resistance heating element 52. The printing pattern was a pattern consisting of concentric circles and bent lines as shown in FIG. 5, and the width of the conductive paste layer was 10 m.
m, and its thickness was 12 μm. In addition, a conductive paste B was filled into a portion to be a through hole to form a filling layer 580.

The green sheet 70 after the above processing is completed.
37 green sheets 70 on which no conductor paste is printed are printed on the upper side (heating surface), 13 sheets on the lower side, 130 ° C.
The layers were laminated at a pressure of Pa (FIG. 8A).

(4) Next, the obtained laminate was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. under a pressure of 15 M
Hot pressing was performed at Pa for 10 hours to obtain a 3 mm-thick aluminum nitride sintered body. This was cut out into a disk shape of 230 mm, and the surface was polished with a diamond paste having an average particle size of 1 μm, so that the surface of the contact portion was JIS R06.
01, Rmax = 2 μm, and a resistance heating element 52 having a thickness of 6 μm and a width of 10 mm (aspect ratio: 1666) inside
And a ceramic substrate 51 having a through hole 72.

(5) Next, the plate obtained in (4) is
After polishing with a diamond grindstone, a mask was placed, and a bottomed hole 54 for a thermocouple and a through hole 55 for inserting a lifter pin for carrying a silicon wafer or the like were provided on the surface by blasting with glass beads. (FIG. 8
(B)).

(6) Further, a portion immediately below the through hole 72 is cut out with a drill to have a diameter of 3.0 mm and a depth of 0.5.
A through hole 72 is formed by exposing the through hole 72 (FIG. 8 (c)).
(FIG. 8D).

(7) A plurality of thermocouples for temperature control are embedded in the bottomed holes 54, filled with a polyimide resin, and
Cured for 2 hours at ° C.

(8) After this, the ceramic substrate 11 is
Support container 20 having substrate receiving portion 20a as shown in FIG.
1 through a heat insulating ring 28 having a sleeve 25 therein as shown in FIG. 1, and a connecting member 2 inserted through the holding member 24, the sleeve 25 and the substrate receiving portion 20a.
In 2, the ceramic substrate 11 was fixed to the support container 20.
Further, the lead wire 14 extending from the external terminal 13 was pulled out to the outside through the through hole of the support container 20, and the production of the hot plate unit 500 was completed.

(Example 3) In the same manner as in Example 1, after manufacturing the ceramic heater 10 having the resistance heating element 12 formed on the surface, the external terminals 13 and the temperature measuring element 17 were installed. The ceramic heater 10 is connected to the support container 2 via the heat insulating ring 38 having the protrusions 21 as shown in FIG.
0, and by performing wiring work such as lead wires,
The manufacture of the hot plate unit 200 has been completed.

(Example 4) In the same manner as in Example 2, after the ceramic heater 50 having the resistance heating element 52 formed therein was manufactured, the external terminals 53 and the temperature measuring element 57 were installed. The ceramic substrate 51 is placed on a supporting container 60 via a heat insulating ring 78 having protrusions 61 as shown in FIG.
And the wiring work of the lead wire and the like was performed, thereby completing the production of the hot plate unit 600.

(Comparative Example 1) After the ceramic heater 10 was manufactured in the same manner as in Example 1, as shown in FIG. 9, the ceramic substrate 11 was interposed via a heat insulating ring 88 having no sleeve therein. Was placed in the support container 20 and wiring work such as lead wires was performed to manufacture a hot plate unit.

(Comparative Example 2) After manufacturing a ceramic substrate 51 in the same manner as in Example 2, as shown in FIG.
The hot plate unit was manufactured by installing the ceramic substrate 51 in the support container 60 through a heat insulating ring having no sleeve therein and performing wiring work such as lead wires.

The hot plate units according to Examples 1 to 4 and Comparative Examples 1 and 2 were energized and heated to 200 ° C., and then allowed to stand for 5 hours, and the temperature of the entire heated surface was measured with a thermoviewer (IR162012 manufactured by Nippon Datum Co., Ltd.). 0012)
Was measured.

In the hot plate units according to Examples 1 to 4, the entire heating surface was at a substantially uniform temperature, whereas in the hot plate units according to Comparative Examples 1 and 2,
Temperature variation was observed in a portion near the outer periphery of the ceramic substrate.

The difference (ΔT ° C.) between the maximum temperature and the minimum temperature of the heated surface was measured using this thermoviewer. The inclination of the ceramic substrate constituting the hot plate unit from the horizontal plane was measured using a laser displacement meter.
When performing the measurement, first, eight points near the outer peripheral edge of the ceramic substrate are measured so that the object is rotated by 45 ° from the center, the displacement is measured by a laser displacement meter, and from the obtained data, The inclination of the ceramic substrate on a diagonal line passing through the center was calculated, and the largest inclination was defined as the inclination of the substrate. The results are shown in Table 1.

[0149]

[Table 1]

As is clear from the results shown in Table 1, the hot plate units according to Examples 1 to 4 had a small temperature difference, whereas the hot plate units according to Comparative Examples 1 and 2 had a small temperature difference. Was getting bigger. Also,
The inclination from the horizontal plane was horizontal in the hot plate units according to Examples 1 to 4, whereas the ceramic heaters according to Comparative Examples 1 and 2 were inclined with respect to the horizontal.

[0151]

As described above, according to the hot plate unit of the present invention, the heat insulating ring for fixing the ceramic substrate is provided with the sleeve made of a resin having a softening point higher than that of the heat insulating ring. Even when the temperature of the ceramic substrate is high, the mechanical strength around the connecting member is maintained, and the horizontality of the ceramic substrate can be maintained permanently. Accordingly, in the process of forming the conductor circuit on the semiconductor wafer to be heated, there is no difference in the light irradiation amount during the exposure processing, and the conductor circuit is formed as set on the semiconductor wafer. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one example of a hot plate unit of the present invention.

FIG. 2 is a plan view of the hot plate unit shown in FIG.

FIG. 3 is a cross-sectional view schematically showing another example of the hot plate unit of the present invention.

FIG. 4 is a sectional view schematically showing another example of the hot plate unit of the present invention.

FIG. 5 is a plan view of the hot plate unit shown in FIG.

FIG. 6 is a sectional view schematically showing another example of the hot plate unit of the present invention.

FIGS. 7A to 7D are cross-sectional views schematically showing a part of the manufacturing process of the ceramic substrate constituting the hot plate shown in FIG. 1 of the present invention.

FIGS. 8A to 8D are cross-sectional views schematically showing a part of the manufacturing process of the ceramic substrate constituting the hot plate shown in FIG. 4 of the present invention.

FIG. 9 is a cross-sectional view schematically illustrating an example of a conventional hot plate unit.

[Explanation of symbols]

100, 200, 500, 600 Hot plate unit 10, 50 Ceramic heater 11, 51 Ceramic substrate 12, 52 Resistance heating element 13, 53 External terminal 14, 54 Bottom hole 15, 55 Through hole 16, 56 Wiring 17, 57 Measurement Temperature element 18, 58 Guide tube 19, 59 Refrigerant introduction tube 20, 60 Support container 21, 61 Projection 22, 62 Connection member 23, 63 Nut 24, 64 Hold down fitting 25, 65 Sleeve 26, 66 Lead wire 72 Through hole

Continued on the front page F term (reference) 3K034 AA02 AA03 AA04 AA05 AA08 AA12 AA16 AA19 AA34 AA37 BB06 BB14 BC04 BC12 BC17 CA02 CA16 DA03 DA04 DA05 GA10 GA12 HA01 HA10 3K092 PP20 QA03 QB02 QB03 QB06 QB14 QB48 RF19 RF22 RF27 TT08 UA05 UA06 UB02 VV02 VV03 VV22 VV31

Claims (3)

[Claims] 1. A hot plate unit in which a ceramic substrate is fitted into a heat insulating ring disposed on a support container, and wherein the ceramic substrate is fixed to the support container via the heat insulating ring. On the ring
A through hole for inserting a connecting member for fixing the heat insulating ring to the support container is formed, and a sleeve made of a resin having a softening point higher than the heat insulating ring is fitted into the through hole, A hot plate unit, wherein the connecting member is inserted into a sleeve. 2. The hot plate unit according to claim 1, wherein the sleeve is made of a polyimide resin. 3. The hot plate unit according to claim 1, wherein the ceramic substrate and the heat insulating ring are in point contact with each other.