JP2002141257A - Ceramic heater for semiconductor manufacturing and inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic heater which can be forcibly cooled easily and whose temperature can be lowered quickly. SOLUTION: The surface roughness of a face, opposite to the side of the heating face 11a of a ceramic substrate 11 in the ceramic heater 1, is adjusted to 20 μm or smaller, according to the JIS B0601 Ra, and a cooling fluid can be prevented from turning into turbulent flow. The temperature of the ceramic heater is lowered quickly, by preventing the cooling fluid from becoming the turbulent flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Detailed description of the invention]

[0002]

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

In the manufacturing process of this semiconductor chip,
Various processes such as etching and CVD are performed on the silicon wafer placed on the electrostatic chuck to form a conductive circuit, an element, and the like. Further, a resin for a resist is applied and dried by heating. A ceramic heater is used for such heating, and heaters using carbide or nitride are disclosed in JP-A-11-74064 and JP-A-11-40330.

[0004]

However, the heater disclosed in JP-A-11-74064 and the heater disclosed in JP-A-11-403 are disclosed.
As described in Japanese Patent Application Laid-Open No. Hei 7-130830, when the heater of Japanese Patent No. 30 is to be blown with air or the like to perform forced cooling, there is a certain limit in the temperature drop rate. The present invention provides a heater that facilitates forced cooling of a ceramic heater and realizes rapid temperature drop.

[0005]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, there is a certain limit (10 minutes to decrease the temperature at 50 ° C.) in such a temperature decreasing rate. It has been found that the reason is that the surface roughness of the surface in contact with the cooling fluid is large, and the fluid stays as a turbulent flow, so that heat cannot be taken from the ceramic substrate. By adjusting the surface roughness of the opposite side of the heating surface to 20 μm or less in accordance with JIS B 0601 Ra, the cooling fluid is prevented from being turbulent, the cooling fluid is prevented from being turbulent, and the temperature is rapidly lowered. Was realized.
The inventor of the present invention is a ceramic heater in which a resistance heating element is formed on the surface or inside of a disk-shaped ceramic substrate, and the surface roughness of the opposite side of the heating surface of the ceramic substrate is 20 μm according to JIS B0601 Ra. It is a ceramic heater characterized by the following. In this heater, a cooling fluid is blown from the side opposite to the heating surface of the ceramic substrate to flow through the surface of the ceramic substrate to perform cooling. At this time, since the surface roughness of the surface of the ceramic substrate in contact with the cooling fluid is 20 μm or less in Ra, turbulence does not easily occur, and there is no stagnation of the cooling fluid. Therefore, a rapid temperature drop can be realized. In the present invention, it is particularly desirable to adjust the surface roughness of the side opposite to the heating surface to 2 μm or less according to JIS B0601 Ra. This is because the warpage at the time of temperature rise is small.

In the present invention, it is desirable to have a mechanism for cooling the opposite side of the heating surface with a cooling fluid. In particular,
As shown in FIG. 3, it is desirable to provide a port 27 for supplying a fluid to the bottom surface of the container 22 supporting the ceramic substrate 11. Gas and liquid can be used as the fluid. Gases include air, nitrogen, and inert gases (argon, helium,
Freon) or the like, and water, ethylene glycol, or the like may be used as the liquid. When a resistance heating element is formed on the surface on the opposite side of the heating surface of the ceramic heater, the surface of the resistance heating element has a surface roughness Ra of 20.
It is desirable that it is not more than μm. This is because turbulence is less likely to occur as the surface roughness of the resistance heating element surface is smaller. Also,
The thickness of the surface of the resistance heating element is desirably 100 μm or less. This is because turbulence does not easily occur. The ceramic heater includes an insulating layer formed on a surface opposite to a heating surface, and a resistance heating element formed on the insulating layer surface. At a high temperature, the volume resistivity of the ceramic substrate is reduced, and a short circuit between the heating elements or a leak current is likely to occur. Further, the provision of the insulating layer makes it unnecessary to directly polish the surface of the ceramic substrate. Preferably, the ceramic substrate has a disk shape. This is because the heating surface has excellent temperature uniformity. Preferably, the ceramic substrate is a carbide or nitride ceramic. This is because it has excellent thermal conductivity. The thickness of the ceramic substrate is desirably 25 mm or less. This is because the heat of the resistance heating element is easily transmitted to the heating surface, and the temperature of the outer periphery does not easily decrease. The diameter of the ceramic substrate is 150 mm
Is desirable. Because the area of the heating surface is large,
This is because the outer peripheral temperature is easily reduced, and the present invention is particularly effective. Hereinafter, description will be given according to the embodiment.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A ceramic heater according to the present embodiment uses a nitride ceramic or a carbide ceramic as a ceramic substrate, and uses an oxide ceramic as an insulating layer on the surface of the ceramic substrate. Nitride ceramics have a tendency to decrease in volume resistance at high temperatures due to oxygen solid solution, etc.Carbide ceramics have conductivity unless particularly highly purified.By forming oxide ceramics as an insulating layer, This is because, even at high temperatures or even when impurities are contained, short circuits between circuits can be prevented and temperature controllability can be ensured. The surface on the side opposite to the heating surface of the ceramic substrate preferably has a surface roughness Ra of 0.01 to 20 μm and an Rmax of 0.1 to 200 μm. The surface on the side opposite to the heating surface of the ceramic substrate refers to the surface roughness of the insulating layer itself when the insulating layer is formed on the ceramic substrate.

The nitride ceramic constituting the ceramic substrate includes metal nitride ceramics, for example, aluminum nitride, silicon nitride, boron nitride, titanium nitride and the like. Further, as the carbide ceramic,
Metal carbide ceramics include, for example, silicon carbide, zirconium carbide, titanium carbide, tantalum carbide, tansten carbide and the like. Note that an oxide ceramic may be used as the ceramic substrate, and alumina, silica, cordierite, mullite, zirconia, beryllia, or the like can be used.

In the present invention, it is desirable that a ceramic substrate contains a sintering aid. For example, as a sintering aid for aluminum nitride, alkali metal oxides, alkaline earth metal oxides, and rare earth oxides can be used. Among these sintering aids, CaO, Y ₂ O are particularly used.
₃ , Na ₂ O, Li ₂ O, and Rb ₂ O ₃ are preferred. Also, alumina may be used. The content of these is desirably 0.1 to 20% by weight. In the case of silicon carbide, the sintering aid is B ₄ C, C, or ALN.

According to the present invention, 5 to 50 ceramic substrates are used.
Desirably, it contains 00 ppm of carbon.
By containing carbon, the ceramic substrate can be blackened, and radiant heat can be sufficiently used when used as a heater. The carbon may be amorphous or crystalline. When amorphous carbon is used, a decrease in volume resistivity at high temperatures can be prevented, and when crystalline carbon is used, a decrease in thermal conductivity at high temperatures can be prevented. Because. Therefore, depending on the application, both crystalline carbon and amorphous carbon may be used in combination. The content of carbon is 50 to 2
000 ppm is more preferred.

The thickness of the ceramic substrate of the present invention is desirably 50 mm or less, particularly preferably 25 mm or less. In particular, when the thickness of the ceramic substrate exceeds 25 mm, the heat capacity of the ceramic substrate becomes large. In particular, when the temperature control means is provided for heating and cooling, the temperature followability is reduced due to the large heat capacity. In particular, 5 mm or more is optimal. It is desirable that the thickness exceeds 1.5 mm. The variation in the thickness of the ceramic substrate is preferably ± 3%. The variation in the thermal conductivity is preferably ± 10%.

The insulating layer used in the present invention is desirably an oxide ceramic, and specific examples thereof include silica, alumina, mullite, cordierite, and beryllia. 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.

In the ceramic heater according to the present invention, the semiconductor wafer is placed in a state of being in contact with the wafer mounting surface of the ceramic substrate, and the semiconductor wafer is supported by support pins, support balls, or the like. In some cases, a certain interval is maintained. As the separation distance, 5
5000 μm is desirable. By moving the lifter pins up and down, the semiconductor wafer can receive the wafer from the carrier, place the wafer on a ceramic substrate, or heat the wafer while supporting the wafer.

The diameter of the ceramic substrate of the present invention is 200 m.
m or more is desirable. In particular, it is desirable to be 12 inches (300 mm) or more. This is because it will become the mainstream of next-generation semiconductor wafers. Further, the outer shape of the ceramic substrate is desirably equal to or larger than that of the wafer, and heating may be performed without contact with the wafer. The ceramic substrate preferably has closed pores, and a helium leak amount is preferably 10 ⁻⁷ Pa · m ³ / sec or less. This is to prevent gas leakage of the refrigerant for forced cooling. Further, the volume resistivity of the ceramic substrate or the volume resistivity of the insulating layer is 10 ⁵ Ω ·
cm or more. This is to ensure insulation between the resistance heating elements. The flatness of the ceramic substrate is 50
Advantageously, it is less than μm.

The ceramic heater according to the present invention is used in an apparatus for manufacturing a semiconductor or inspecting a semiconductor. Specific examples of the apparatus include an electrostatic chuck, a wafer prober, and a susceptor. When used as an electrostatic chuck, in addition to a resistance heating element, an electrostatic electrode, an RF electrode, when further used as a wafer prober,
A chuck top conductor layer is formed as a conductor on the surface, and a guard electrode and a ground electrode are formed inside as a conductor. Further, the ceramic substrate for a semiconductor device of the present invention is optimally used at 100 ° C. or higher, preferably 200 ° C. or higher.

In the present invention, a thermocouple can be embedded in the bottomed hole of the ceramic substrate as required. This is because the temperature of the resistance heating element can be measured using a thermocouple, and the temperature and the amount of current can be changed based on the data to control the temperature. The size of the junction of the thermocouple metal wire is
The diameter is preferably equal to or larger than the element diameter of each metal wire and 0.5 mm or less. With such a configuration, the heat capacity of the joint portion is small, and the temperature is accurate,
In addition, it is quickly converted to a current value. For this reason,
The temperature controllability is improved and the temperature distribution on the heated surface of the wafer is reduced. As the thermocouple, for example, JIS
-C-1602 (1980).
Type, R type, B type, S type, E type, J type, T type thermocouple. The temperature measuring element may be adhered to the bottom of the bottomed hole 14 using gold brazing, silver brazing, or the like, or may be inserted into the bottomed hole 14 and then sealed with a heat-resistant resin, You may use both together. 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%
At least one selected from a 2.5 wt% Au-18.5 to 17.5 wt% Ni alloy 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-Cu
A system can be used.

The heating element 12 is preferably divided into at least two or more circuits as shown in FIG.
More preferably, the circuit is divided into two to ten circuits.
By dividing the circuit, the amount of heat generated can be changed by controlling the power supplied to each circuit.
Is adjusted.

The pattern of the heating element 12 includes concentric circles, for example, spirals, eccentric circles, bent lines, and the like.

In the present invention, before forming the heating element, an insulating layer is provided on the surface of the ceramic substrate. The 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 baking, or by sputtering, CVD, or the like. Alternatively, the surface of the ceramic substrate may be fired in an oxidizing atmosphere to form an oxide layer. When the heating element is formed on the surface of the ceramic substrate 11, a conductive paste containing metal particles is applied to the surface of the ceramic substrate 11 to form a conductive paste layer having a predetermined pattern. A method of sintering metal particles on the surface is preferred. The sintering of the metal is sufficient if the metal particles and the metal particles and the ceramic are fused. In the present embodiment, a pattern as shown in FIG. 1 is adopted. On the ceramic substrate 11, there are 12d as the resistance heating element formation area 1, 12c as the resistance heating element formation area 2, 12b as the resistance heating element formation area 3, and 12a as the resistance heating element formation area 4. Between the resistance heating element formation area 1 and the resistance heating element formation area 2, the resistance heating element formation area 2 and the resistance heating element formation area 3
During this period, a resistance heating element formation area is provided between the resistance heating element formation area 3 and the resistance heating element formation area 4 as a buffer area.
Even if a large amount of power is applied to the resistance heating element formation area 2 and the temperature rises due to the presence of the buffer area, the resistance heating element formation area 1 and the resistance heating element formation area 3 are affected because the buffer area exists. Do not give. For this reason, temperature control such as lowering the temperature of the resistance heating element formation region 1 and the resistance heating element formation region 3 is unnecessary, and the temperature difference on the heating surface can be reduced by simple control. The outermost periphery of the formation region of the resistance heating element needs to be within 35 mm from the side surface of the ceramic substrate, and optimally within 25 mm. This is because, if it is within 25 mm, the amount of warpage can be extremely reduced. Further, it is desirable that the distance from the side surface of the ceramic substrate at the outermost periphery of the formation region of the resistance heating element be 0.5 mm or more. If the thickness exceeds 0.5 mm, when the supporting container is made of metal, an electrical short circuit occurs or the handling property is reduced.

In this embodiment, the width of the resistance heating element forming region is adjusted to 5% to 30% of the diameter. A through-hole 15 is formed in the ceramic substrate 10 and a lifter pin is inserted therein. The surface roughness of the through hole is 0.05 to Rmax.
The thickness is 200 μm and the Ra is 0.005 to 20 μm. A temperature measuring element is formed in the bottomed hole 14. A terminal portion 13 is formed on the resistance heating element 12. Concentric circles, spirals, and bent patterns are formed as resistance heating element formation areas.
It is desirable that one resistance heating element formation region is one circuit. This is because one circuit is easier to control. When a heating element is formed on the surface of the ceramic substrate 11, the thickness of the heating element is preferably 1 to 30 μm, more preferably 1 to 10 μm.

When a heating element is formed on the surface of the ceramic substrate 11, the width of the heating element is 0.1 to 20 mm.
Is preferable, and 0.1 to 5 mm is more preferable.

The resistance of the heating element can be varied depending on its width and thickness, but the above range is most practical. The resistance value increases as the resistance value decreases and the resistance value decreases.

By setting the formation position of the heating element in this way, the heat generated from the heating element is diffused throughout the ceramic substrate as the heat propagates, and the surface of the object to be heated (the silicon wafer) is heated. The temperature distribution is made uniform, and as a result, the temperature in each part of the object to be heated is made uniform.

The heating element may be rectangular or elliptical in cross section, but is preferably flat. This is because the flattened surface tends to radiate heat toward the heated surface of the wafer, so that the temperature distribution on the heated surface of the wafer is hardly generated. The aspect ratio of the cross section (width of heating element / thickness of heating element) is 10 to 5000
It is desirable that By adjusting to this range, the resistance value of the heating element can be increased, and the temperature uniformity of the wafer heating surface can be ensured.

When the thickness of the heating element is constant, if the aspect ratio is smaller than the above range, the amount of heat transmission in the direction of the wafer heating surface of the heater plate 11 becomes small, and the heat distribution approximates the pattern of the heating element. Is generated on the wafer heating surface,
Conversely, if the aspect ratio is too large, the temperature immediately above the center of the heating element becomes high, and eventually, a heat distribution similar to the pattern of the heating element is generated on the wafer heating surface. Therefore, considering the temperature distribution, the aspect ratio of the cross section is 1
It is preferably from 0 to 5000.

When the heating element is formed on the surface of the substrate 11, the aspect ratio is 10 to 200. When the heating element is formed inside the substrate 11, the aspect ratio is 200 to 500.
It is desirable to set to 0.

When the heating element is formed inside the substrate 11, the aspect ratio becomes larger. However, when the heating element is provided inside, the distance between the wafer heating surface and the heating element becomes shorter. This is because the heating element itself needs to be flattened because the temperature uniformity of the surface is reduced.

The conductive paste is not particularly limited, but preferably contains not only metal particles or conductive ceramic for ensuring conductivity, but also resin, solvent, 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. The metal particles or conductive ceramic particles preferably have a particle size of 0.1 to 100 μm. 0.1μ
If the particle size is too small, it is easily oxidized.
If the thickness exceeds μm, sintering becomes difficult and the resistance value increases.

Although the shape of the metal particles is spherical,
It may be scaly. When these metal particles are used, they may be a mixture of the above-mentioned spheres and the above-mentioned flakes. When the metal particles are scaly, or a mixture of spherical and scaly, it is easy to hold the metal oxide between the metal particles, and the adhesion between the heating element and the nitride ceramic is improved. This is advantageous because it can be ensured and the resistance value can be increased.

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 described above, the conductor paste is preferably made by adding a metal oxide to metal particles and sintering the heating element with the metal particles and the metal oxide. By sintering the metal oxide together with the metal particles in this manner, the nitride ceramic or carbide ceramic serving as the heater plate can be brought into close contact with the metal particles.

It is not clear why the mixing of the metal oxide with the nitride ceramic or the carbide ceramic improves the adhesion, but the surface of the metal particles and the surface of the nitride ceramic and the carbide ceramic are slightly oxidized. It is considered that an oxide film is formed by sintering and integrating the oxide films via the metal oxide, and the metal particles adhere to the nitride ceramic or the carbide ceramic.

As the metal oxide, for example, at least one selected from the group consisting of lead oxide, zinc oxide, silica, boron oxide (B ₂ O ₃ ), alumina, yttria, and titania is preferable.

This is because these oxides can improve the adhesion between the metal particles and the nitride ceramic or the carbide ceramic without increasing the resistance value of the heating element.

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 in these ranges, the adhesion to the nitride ceramic 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 heating element is formed using the conductor paste having such a configuration is preferably from 1 to 45 mΩ / □.

When the sheet resistivity exceeds 45 mΩ / □, the amount of heat generated becomes too small with respect to the applied voltage, and it is difficult to control the amount of heat generated in the heater plate 11 having a heating element on the surface of the heater plate. Because. When the addition amount of the metal oxide is 10% by weight or more, the sheet resistivity is 50 mΩ / □.
, And the calorific value becomes too small to make the temperature control difficult, and the uniformity of the temperature distribution decreases.

When the heating element is formed on the surface of the substrate 11, a coating layer (see FIG. 2) 12a is formed on the surface of the heating element.
Is desirably formed. This is to prevent the internal metal sintered body from being oxidized to change the resistance value.
The thickness of the coating layer to be formed is preferably 0.1 to 10 μm. In this case, the surface roughness of the heating element is the surface roughness of the coating layer.

As the coating layer, resin, glass, and metal can be used. Polyimide resin and fluororesin can be used as the resin, and borosilicate glass can be used as the glass. The metal used for forming the metal coating layer is not particularly limited as long as it is a non-oxidizing metal, and specifically, for example,
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.

The heating element requires a terminal for connection to a power supply, and this terminal is attached to the heating element via solder. Nickel prevents heat diffusion of the solder. As the connection terminal, for example, a terminal pin 13 made of Kovar is used.

When connecting the connection terminals, the solder
Alloys such as silver-lead, lead-tin, and bismuth-tin can be used. The thickness of the solder layer is 0.1 to 50.
μm is preferred. This is because the range is sufficient to secure connection by soldering.

Next, the structure including the cooling structure of the ceramic heater will be described. FIG. 3 shows a schematic diagram. This ceramic heater 10 has a resistance heating element 12 provided inside a ceramic substrate 11. The ceramic substrate 11 has a bottomed hole 14 into which a temperature measuring element 18 is embedded and a through hole 15 into which a lifter pin is inserted. Further, a through hole 20 is connected to the resistance heating element 12, and a washer 17 is connected to the through hole 20. Washer 17
Is fitted into a bag hole 23 provided in the ceramic substrate 11. The conductive wire 16 is connected to the washer 17, the conductive wire 16 is connected to the power supply 26, and the power supply 26 is connected to the temperature measuring element 18.
Is controlled by the control unit 25 connected to The ceramic substrate 11 is fitted into a support container 22 via a heat insulating material 21. The support container 22 has a substrate receiving portion 22b and a bottom plate receiving portion 22c. A bottom plate 24 is formed in the bottom plate receiving portion 22c, and the through holes 27a, 2
7b is provided. Further, a port 27 for supplying a cooling fluid is formed in the bottom plate 24. The cooling fluid flows through the surface opposite to the heating surface 11a and is discharged from the opening of the bottom plate 24. Although the resistance heating element 12 is provided inside the ceramic substrate 11 in FIG. 3, it may be formed on the surface of the ceramic substrate 11 as shown in FIG. In this case, it is desirable to adjust the surface roughness of the resistance heating element to 20 μm or less in Ra and to reduce the thickness to 100 μm or less.

Next, a method for manufacturing the ceramic heater of the present invention will be described. Here, a method of manufacturing the ceramic heater 10 in which a heating element is formed inside a heater plate will be described. (1) Heater plate manufacturing process A slurry is prepared by blending a sintering aid such as yttria or a binder as necessary with the above-described nitride ceramic or carbide ceramic powder, and the slurry is spray-dried or the like. The granules are formed by a method, and the granules are placed in a mold or the like and pressed to be formed into a plate shape or the like, thereby producing a green body. Next, if necessary, a portion serving as a through hole 35 for inserting a support pin for supporting a silicon wafer and a portion serving as a bottomed hole 34 for embedding a temperature measuring element such as a thermocouple are formed in the formed body. Form.

Next, the formed body is heated, fired and sintered to produce a ceramic plate. Thereafter, the substrate 31 is manufactured by processing into a predetermined shape.
The shape may be such that it can be used as it is after firing. By performing heating and baking while applying pressure, it is possible to manufacture a substrate 31 having no pores. Heating and firing may be performed at a temperature equal to or higher than the sintering temperature. For a nitride ceramic or a carbide ceramic, the temperature is 1000 to 2500C. Of the main surface of the substrate, a surface opposite to a heating surface for heating a wafer or the like is polished. Polishing is performed with a diamond grindstone or diamond paste.

(2) Step of Printing Conductive Paste on Substrate The conductive paste is generally a high-viscosity fluid composed of metal particles, resin and solvent. The conductor paste is printed on a portion where the heating element is to be provided by screen printing or the like to form a conductor paste layer. Since the heating element needs to have a uniform temperature over the entire substrate, it is desirable to print the heating element in a hybrid pattern of concentric and bent lines as shown in FIG. The conductor paste layer is desirably formed such that the cross section of the heating element 13 after firing has a rectangular and flat shape.

(3) Firing the conductive paste The conductive paste layer printed on the bottom surface of the substrate is heated and fired.
While removing resin and solvent, sintering metal particles,
The heating element 32 is formed by baking on the bottom surface of the substrate 11. The temperature of the heating and firing is preferably from 500 to 1000C. If the above-mentioned metal oxide is added to the conductor paste, the metal particles, the substrate and the metal oxide are sintered and integrated, so that the adhesion between the heating element 12 and the substrate 11 is improved.

(4) Formation of Metal Coating Layer It is desirable to provide a metal coating layer on the surface of the heating element 32. The metal coating layer can be formed by electrolytic plating, electroless plating, sputtering, or the like, but in consideration of mass productivity, electroless plating is optimal.

(5) Attachment of Terminals and the like Terminals (terminal pins 13) for connection to a power source are attached to the end of the pattern of the heating element 12 by soldering. Further, a thermocouple is fixed to the bottomed hole 14 with a silver solder, a gold solder, or the like, and sealed with a heat-resistant resin such as polyimide, and the manufacture of the ceramic heater 10 is completed. In the ceramic heater of the present invention, an electrostatic chuck may be provided by providing an electrostatic electrode, or a wafer prober may be provided by providing a chaptop conductor layer.

[0051]

EXAMPLES (Example 1) Production of a ceramic heater made of SiC (see FIG. 2) (1) 100 parts by weight of SiC powder (average particle size: 0.3 μm) and 4 parts by weight of sintering aid B ₄ C , A composition comprising 12 parts by weight of an acrylic binder and alcohol was spray-dried to prepare a granular powder.

(2) Next, this granular powder was put into a mold and molded into a flat plate to obtain a formed product (green). (3) The processed form is processed at 2100 ° C. and pressure:
Hot pressing was performed at 18 MPa to obtain a SiC ceramic substrate having a thickness of 3 mm. Next, a disk having a diameter of 210 mm was cut out from the surface of the plate, and the surface was Ra = 0.1 μm.
m was mirror-polished to obtain a ceramic substrate 11.
A mixture of 25 parts by weight of tetraethyl silicate, 37.6 parts by weight of ethanol and 0.3 part by weight of hydrochloric acid was applied to the ceramic substrate 11 by spin coating with a sol solution obtained by hydrolytic polymerization with stirring for 24 hours. After drying at 80 ° C. for 5 hours and firing at 1000 ° C. for 1 hour, a 2 μm thick SiO ₂ film 18 is formed on the surface of the SiC ceramic substrate 11.
0 was formed. The SiO ₂ film is almost specular and JIS
B 0601 Ra = 0.1 μm. The surface roughness was measured using a surface profiler (PAL manufactured by KAL Tencor).
-11).

Drilling is performed on the formed body to form a through hole 15 for inserting a support pin of a silicon wafer 19 and a bottomed hole 14 for embedding a thermocouple (diameter: 1.1 mm, depth: : 2 mm).

(4) The ceramic substrate 1 obtained in the above (3)
1, a conductor paste was printed by screen printing. The printing pattern was a concentric and bent hybrid pattern as shown in FIG. The pattern includes terminal portions 13a, 1
3b, 13c, 13d and 13e are formed. However, the outermost circumference of the resistance heating element formation region was set to be 30 mm from the side surface of the ceramic substrate. As the conductor paste, Solvest PS603D manufactured by Tokuri Chemical Laboratory, which is used for forming through holes in a printed wiring board, was used. This conductor paste is a silver paste, and silver 1
A metal oxide composed of lead oxide (5% by weight), zinc oxide (55% by weight), silica (10% by weight), boron oxide (25% by weight), and alumina (5% by weight) was added to 00 parts by weight. It contained 7.5 parts by weight. The silver particles had an average particle size of 4.5 μm and were scaly.

(5) Next, the ceramic substrate 11 on which the conductor paste is printed is heated and fired at 780 ° C. to sinter silver in the conductor paste and to bake the substrate 11 on the substrate 11.
Heating element 12 was formed. The silver heating element 12 has a thickness of 5 μm.
m, the width was 2.4 mm, and the sheet resistivity was 7.7 mΩ / □.

(6) Nickel sulfate 80 g / l, sodium hypophosphite 24 g / l, sodium acetate 12 g / l,
The substrate 11 prepared in the above (5) was immersed in an electroless nickel plating bath composed of an aqueous solution having a concentration of boric acid of 8 g / l and ammonium chloride of 6 g / l. A coating layer (nickel layer) 12a was deposited. The surface roughness of the surface of the resistance heating element is JIS B 060
1 Ra was 0.5 μm.

(7) A silver-lead solder paste (manufactured by Tanaka Kikinzoku) was printed by screen printing on a portion where a terminal for securing connection to a power supply was to be formed, to form a solder layer. Next, the terminal pins 13 made of Kovar were placed on the solder layer, and heated and tapped at 420 ° C. to attach the terminal pins 13 to the surface of the heating element 12.

(8) A thermocouple for controlling temperature is provided in the bottomed hole 1
4 and embedded and fixed with a ceramic adhesive (Aron Ceramic manufactured by Toa Gosei).
I got

Example 2 (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size: 1.1 μm), yttria (average particle size:
0.4 μm) 4 parts by weight, acrylic binder 11.5 parts by weight, dispersant 0.5 parts by weight, SiC 0, 5, 10% by weight
(Details are shown in Table 1), and a paste obtained by mixing 53 parts by weight of an alcohol composed of 1-butanol and ethanol was molded by a doctor blade method to a thickness of 0.1.
A 47 mm green sheet was obtained.

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

(3) 100 parts by weight of tungsten carbide particles having an average particle diameter of 1 μm, acrylic binder 3.0
By weight, 3.5 parts by weight of the α-terpineol solvent and 0.3 parts by weight of the dispersant were mixed to prepare a conductor paste A. A conductive paste B was prepared by mixing 100 parts by weight of tungsten particles having an average particle diameter of 3 μm, 1.9 parts by weight of an acrylic binder, 3.7 parts by weight of an α-terpineol solvent, and 0.2 parts by weight of a dispersant. This conductive paste A
Was printed on a green sheet by screen printing to form a conductor paste layer. The printing pattern was a concentric pattern.

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

(4) Next, the obtained laminate was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. under a pressure of 150 ° C.
It was hot-pressed at kg / cm ² for 3 hours to obtain an aluminum nitride plate having a thickness of 3 mm. This was cut out into a disk shape of 230 mm, and a plate-shaped body made of aluminum nitride having a resistance heating element with a thickness of 6 μm and a width of 10 mm inside was obtained. Plate-like material is made of Malto's diamond paste (particle size 0.25
μm) and the surface is JIS B 0601 R
a = 0.5 μm.

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

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

(7) Next, a plurality of thermocouples for temperature control were embedded in the bottomed holes.

(Example 3) According to Example 2, the plate was polished with a diamond paste (particle size: 1 µm) made by Malto, and the surface was JIS B 0601 Ra = 3 µm.
m. Example 4 According to Example 2, the plate was polished with # 800 diamond and stone. The surface is JIS B 06
01Ra = 18 μm. (Example 5) The same as Example 2, except that the thickness of the plate-like body was set to 20 mm.

Comparative Example 1 According to Example 2, but the plate was not polished as in JP-A-7-130830. The surface roughness of the surface is JIS B 0601 Ra =
It was 21 μm. (Comparative Example 2) According to Example 2, but disclosed in JP-A-7-1308.
As in the case of JP-A No. 30, the plate was not polished. The diameter of the plate was set to 150 mm. (Comparative Example 3) According to Example 2, except that the thickness of the
mm. As described above, the heaters of Example and Comparative Example were
Table 1 shows the results of measuring the time until the temperature was raised to 40 ° C. and the temperature was lowered to 90 ° C. by blowing air at 100 cm ³ / sec.
Shown in The greater the surface roughness of the surface in contact with air, the more difficult it is to lower the temperature. In addition, when the diameter of the plate-like body is 150 mm, it can be seen that the temperature drop rate is relatively fast as 6 minutes without polishing. Further, when the thickness is 25 mm, the heat capacity becomes too large, and the temperature drop rate becomes as slow as 8 minutes.

[0069]

[Table 1]

[0070]

As described above, according to the present invention, the temperature reduction time can be shortened, and the throughput time of semiconductor manufacturing can be shortened.

[Brief description of the drawings]

FIG. 1 is a pattern diagram of a resistance heating element of a ceramic heater according to the present invention.

FIG. 2 is a sectional view of the ceramic heater of the present invention.

FIG. 3 is a structural sectional view of the ceramic heater of the present invention.

[Explanation of symbols]

 Reference Signs List 10 ceramic heater 11 ceramic substrate 12 resistance heating element 13 terminal pin 14 bottomed hole 15 through hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 3/10 H05B 3/12 B 3/12 3/20 393 3/20 393 3/68 3/68 H01L 21/30 567 F term (reference) 3K034 AA02 AA03 AA08 AA10 AA34 AA37 BA02 BA05 BA08 BB06 BB14 BC04 BC12 BC17 BC23 BC29 CA02 CA26 DA04 JA10 3K092 PP20 QA05 RF03 RF11 RF19 RF22 RF27 VV15 4M106 HAA3 HA33 HA32 MA28 MA32 MA33 5F046 KA04

Claims (8)

[Claims] 1. A ceramic heater having a resistance heating element formed on the surface or inside of a ceramic substrate, wherein a surface roughness of a side opposite to a heating surface of the ceramic substrate is 2 in Ra.
A ceramic heater for a semiconductor manufacturing / inspection apparatus, wherein the ceramic heater has a thickness of 0 μm or less. 2. The ceramic heater for a semiconductor manufacturing / inspection apparatus according to claim 1, wherein said ceramic heater has a mechanism for cooling a side opposite to a heating surface with a cooling fluid. 3. The ceramic heater according to claim 1, wherein a resistance heating element is formed on a surface opposite to a heating surface, and a surface roughness of the surface of the resistance heating element is 20 μm or less in Ra. Ceramic heater for semiconductor manufacturing and inspection equipment. 4. The ceramic heater according to claim 1, wherein an insulating layer is formed on a surface on a side opposite to a heating surface, a resistance heating element is formed on the surface of the insulating layer, and the surface roughness of the insulating layer is 20 μm or less in Ra. The ceramic heater for a semiconductor manufacturing / inspection apparatus according to any one of claims 1 to 3. 5. The ceramic heater according to claim 1, wherein the ceramic substrate has a disk shape. 6. The ceramic heater for a semiconductor manufacturing / inspection apparatus according to claim 1, wherein said ceramic substrate is a carbide or nitride ceramic. 7. The thickness of the ceramic substrate is 25 mm.
The ceramic heater for a semiconductor manufacturing / inspection apparatus according to claim 1, wherein the ceramic heater is: 8. The diameter of the ceramic substrate is 150 m.
The ceramic heater for a semiconductor manufacturing / inspection apparatus according to any one of claims 1 to 7, wherein the number exceeds m.