JP2003077783A - Ceramic heater for semiconductor manufacturing/ inspecting device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic heater for a semiconductor manufacturing/ inspecting device capable of uniformizing a temperature of a heating surface without generating chipping, cracks or the like on a ceramic substrate. SOLUTION: For the ceramic heater for the semiconductor manufacturing/ inspecting device, a resistance heating element composed of one or a plurality of circuits is formed inside a disk-like ceramic substrate. The circuit is formed by connecting one or a plurality of pieces of metal wiring through a plurality of conductive pad parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly used in the semiconductor industry to manufacture semiconductors used for ceramic heaters, electrostatic chucks, chuck top plates for wafer probers and the like.
The present invention relates to a ceramic heater for an inspection device and a manufacturing method thereof.

[0002]

2. Description of the Related Art A heater using a metal base material such as stainless steel or aluminum alloy has been conventionally used in semiconductor manufacturing and inspection equipment including etching equipment and chemical vapor deposition equipment.

However, since the heater made of metal has a thick heater plate, there are problems that the heater is heavy and bulky.
Further, due to these, there is a problem in the temperature followability. Further, since it is made of metal, it has a problem of poor corrosion resistance against corrosive gas. On the other hand, a ceramic heater using a nitride ceramic or a carbide ceramic having a high thermal conductivity and a high strength is used instead of a metal heater.

FIG. 10A is a bottom view schematically showing an example of a conventional ceramic heater, and FIG. 10B is a partially enlarged sectional view thereof. In the ceramic heater 70, a plurality of annular grooves 74 are formed on the surface of a ceramic substrate 71, and a metal coil 72 serving as a resistance heating element is formed inside the groove 74.
Is provided. The end 73 of the coil 72 is connected to a power supply (not shown) via a lead wire 77, and the ceramic heater 70 can be heated by supplying electric power to the coil 72.

FIG. 11A is a plan view schematically showing another example of the conventional ceramic heater, and FIG. 11B is a partially enlarged sectional view thereof. The ceramic heater 80 includes a wire 8 serving as a resistance heating element inside a ceramic substrate 81.
2 is buried, and each of the wires 82 constitutes one circuit. The end portion 83 of the wire 82 is connected to a power source (not shown) via a lead wire 87, and the ceramic heater 80 can be heated by supplying electric power to the wire 82.

FIG. 12A is a plan view schematically showing another example of the conventional ceramic heater, and FIG. 12B is a partially enlarged sectional view thereof. In the ceramic heater 90, a resistance heating element 92 formed by sintering metal particles is provided on the surface of a ceramic substrate 91, and an external terminal 93 is provided at an end of the resistance heating element 92. External terminal 9
3 is connected to a power source (not shown) via a lead wire 97, and can supply electric power to the resistance heating element 92 to heat the ceramic heater 90.

Incidentally, the resistance heating element as shown in FIG.
It was formed by screen-printing a conductor paste containing metal particles on the surface of a ceramic substrate so as to form a predetermined heating element pattern, and then heating and firing.

Further, Japanese Unexamined Patent Publication No. 2000-340343 discloses a ceramic heater in which a resistance heating element is embedded inside a ceramic substrate. FIG. 13 is a plan view showing such a ceramic heater. In the ceramic heater 500, a resistance heating element 52 including a wide low resistance region 52a and a narrow high resistance region 52b is embedded inside a ceramic substrate 51. In addition, the pair of power supply electrodes 53 a, 5 provided at the end of the resistance heating element 52.
Electric power can be supplied to the resistance heating element 52 via 3b to heat the ceramic heater 500.

The ceramic heaters shown in FIGS. 10 to 13 warp the ceramic substrate even if they are thermally expanded during heating.
Strain was less likely to occur, and temperature followability with respect to changes in applied voltage and current amount was also good.

[0010]

However, as shown in FIG.
In the ceramic heater 70 shown in FIG. 3, the coil 72 may be protruded from the groove 74 or may be distorted in the groove 74 due to impact during use, thermal expansion due to repeated temperature increase and temperature decrease, and the like. The coil 72 may be displaced.

In the ceramic heater, the arrangement of the circuit of the resistance heating element is set so that the temperature of the heating surface of the ceramic heater can be made uniform.
As described above, the displacement of the resistance heating element such as the coil causes the temperature of the heating surface of the ceramic heater to become non-uniform.

In the ceramic heater 80 shown in FIG. 11, as a resistance heating element, one wire 82 integrally formed for each circuit is used. However, to form one circuit with one wire, the wire 8
2 must be relatively long. as a result,
The amount of change in the length of the wire 82 due to thermal expansion increases,
Along with this, a large thermal stress is generated, and there is a problem that the ceramic substrate 81 is chipped or cracked.

Further, the ceramic heater 9 shown in FIG.
The resistance heating element 92 of 0 was formed by screen-printing a conductor paste, followed by heating and firing, so that the resistance heating element 92 sometimes varied in thickness depending on the printing direction and the like. As a result, the resistance value may vary, and the temperature of the heating surface may become uneven.

Further, the ceramic heater 5 shown in FIG.
The resistance heating element 52 at 00 has a wide low resistance region 52a.
The high resistance region 52b is a hot spot and generates heat. However, the low resistance region 52a also acts as a heating element, so that the temperature variation is large.

[0015]

In view of the above-mentioned problems, the present inventors have proposed a ceramic heater capable of making the temperature of a heating surface uniform without causing cracks or cracks in the ceramic substrate. As a result of earnest research aimed at obtaining a ceramic heater in which a resistance heating element is formed by connecting a metal wiring functioning as a heating element inside a ceramic substrate through a plurality of conductive pad portions. In that case, even if the temperature rise and temperature decrease are repeated, no cracks or cracks are generated in the ceramic substrate, and
Finding that the temperature of the heating surface can be made uniform,
The present invention has been completed.

That is, the ceramic heater for semiconductor manufacturing / inspecting equipment of the present invention is a ceramic heater for semiconductor manufacturing / inspecting equipment in which a resistance heating element composed of one or a plurality of circuits is formed inside a disk-shaped ceramic substrate. The above-mentioned circuit is a ceramic heater for a semiconductor manufacturing / inspection apparatus, characterized in that it is formed by connecting one or a plurality of metal wirings through a plurality of conductive pad portions.

For example, as shown in FIG. 10, when each circuit to be a resistance heating element is formed by one wire, each wire must be relatively long. Since the amount of change in length due to thermal expansion of the wire is proportional to the length of the wire, the amount of change in length of the wire due to thermal expansion increases when a long wire is used. As a result, a large thermal stress is generated, which may cause chipping or cracks in the ceramic substrate.

However, in the ceramic heater for semiconductor manufacturing / inspection equipment of the present invention, the circuit serving as the resistance heating element is formed by connecting one or a plurality of metal wirings through a plurality of conductive pad portions. Therefore, the metal wiring is relatively short. Therefore, the amount of change in the length of the metal wiring due to the thermal expansion is small, so that the thermal stress caused by the thermal expansion can be reduced. Further, in the ceramic heater for a semiconductor manufacturing / inspecting device of the present invention, the conductive pad portion and the metal wiring are thermally expanded, respectively, at the time of temperature rise, so that the circuit serving as the resistance heating element is The thermal stress can be dispersed as compared with the case where it is formed from a book wire. As a result, cracks and cracks do not occur in the ceramic substrate due to thermal stress.

Further, the metal wiring can be formed by using a wire and / or an elongated foil. The wire and / or the elongated foil can be a predetermined wire such as a commercially available wire or metal foil. Since it is possible to use a molded article having a shape (thickness), as shown in FIG. 12, unlike the resistance heating element formed by screen printing, the thickness of the resistance heating element varies. There is no. As a result, it is possible to suppress variations in the resistance value of the resistance heating element, and it is possible to make the temperature of the heating surface of the ceramic heater for semiconductor manufacturing / inspection equipment uniform.

Further, as shown in FIG. 13, when the circuit to be the resistance heating element is formed from a wide low resistance area and a narrow high resistance area, the low resistance area also functions as a heating element. , Temperature variation becomes large. However, in the ceramic heater for semiconductor manufacturing / inspection equipment of the present invention, since the metal wiring functioning as a resistance heating element is connected via the conductor pad, heat is generated in the metal wiring, and the temperature variation is small.

The plurality of conductive pad portions are arranged on the circumference of a circle having a concentric relationship with the ceramic substrate,
It is desirable that they are arranged substantially evenly.

Further, it is desirable that the metal wiring is made of tungsten and / or tungsten carbide.

A method of manufacturing a ceramic heater for a semiconductor manufacturing / inspecting apparatus according to the present invention is for a semiconductor manufacturing / inspecting apparatus for manufacturing a ceramic heater having a resistance heating element inside a ceramic substrate by stacking and firing green sheets. A method of manufacturing a ceramic heater, comprising forming a plurality of conductive layers on one green sheet by bonding a foil or screen-printing a conductive paste, and connecting the plurality of conductive layers. , A conductor arranging step of mounting and fixing one or more conductive wires and / or elongated foils, a green sheet on which the conductive layer and the wires and / or foils are fixed, and a plurality of other greens. A green sheet laminating step of laminating a sheet to produce a green sheet laminated body, and degreasing of the obtained green sheet laminated body, A method for producing a ceramic heater for semiconductor manufacturing and inspection equipment, which comprises a firing step for formation.

According to the method for manufacturing a ceramic heater for a semiconductor manufacturing / inspecting apparatus of the present invention, as described above, a resistance heating element composed of one or a plurality of circuits is formed inside a disk-shaped ceramic substrate, In addition, in the above circuit, a ceramic heater for a semiconductor manufacturing / inspection apparatus can be obtained in which one or a plurality of metal wirings are connected via a plurality of conductive pad portions. as a result,
It is possible to suppress variations in the resistance value of the resistance heating element, and it is possible to make the temperature of the heating surface of the ceramic heater for semiconductor manufacturing / inspection equipment uniform.

When a plurality of conductive layers are formed by bonding a foil or screen-printing a conductor paste on the one green sheet, the circumference of a circle assumed on the one green sheet is formed. It is desirable that the above-mentioned plurality of conductive layers are arranged substantially evenly on the above.

The electrically conductive wire and / or the elongated foil is preferably made of tungsten and / or tungsten carbide.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION A ceramic heater for a semiconductor manufacturing / inspecting apparatus according to the present invention is for a semiconductor manufacturing / inspecting apparatus in which a resistance heating element composed of one or a plurality of circuits is formed inside a disk-shaped ceramic substrate. A ceramic heater,
The above-mentioned circuit is a ceramic heater for a semiconductor manufacturing / inspection apparatus, which is formed by connecting one or a plurality of metal wirings through a plurality of conductive pad portions.

An embodiment of a ceramic heater for a semiconductor manufacturing / inspecting apparatus of the present invention will be described with reference to the drawings. In the following description, the ceramic heater for semiconductor manufacturing / inspection equipment will be simply referred to as a ceramic heater.

FIG. 1 is a horizontal sectional view schematically showing an example of the ceramic heater of the present invention, and FIG. 2 is a partially enlarged sectional view of the ceramic heater shown in FIG.

As shown in FIG. 1, the ceramic heater 10
A resistance heating element 12 including eight circuits is formed inside a disk-shaped ceramic substrate 11. Each circuit to be the resistance heating element 12 is formed by connecting two metal wirings 12b through a plurality of rectangular or trapezoidal conductive pad portions 12a.

Further, the conductive pad portion 1 which constitutes each circuit
The parts 2a are evenly arranged on the circumference of a circle having a concentric relationship with the ceramic substrate 11 except for the end part of the circuit, and are connected via a straight metal wiring 12b. Therefore, the circuit as a whole constitutes a regular octagonal band-shaped pattern.

A strip-shaped heating element non-forming region is provided between the above eight circuits forming the resistance heating element 12, and each strip-shaped heating element non-forming region has a regular octagonal shape. . In addition, a substantially octagonal heating element non-forming region is also provided in the central portion.

Therefore, as a whole, the resistance heating element forming regions and the heating element non-forming regions are alternately formed from the outside to the inside, and these regions are formed in the size (diameter) and thickness of the ceramic substrate. The temperature of the heating surface can be made uniform by appropriately setting the temperature in consideration.

As shown in FIG. 2, the conductive pad portion 12a provided inside the ceramic substrate 11 has a rectangular cross section, and the metal wiring 12b has a circular cross section. Further, in order to secure the connection between the conductive pad portion 12a and the metal wiring 12b, the metal wiring 12b is, for example, through a conductive adhesive layer 12c formed by using a paste adhesive containing metal particles, Conductive pad 1
2a. A through hole 19 is formed immediately below the conductive pad portion 12a which is an end portion of the resistance heating element 12, and a bag hole 19a for exposing the through hole 19 is formed on the bottom surface 11b. The external terminal 13 is inserted and joined with a brazing material or the like (not shown). For example, a socket (not shown) having a conductive wire is attached to the external terminal 13, and the conductive wire is connected to a power source or the like.

A bottomed hole 14 and a through hole 15 are formed in the ceramic heater 10, and a lifter pin 16 is inserted into the through hole 15. By moving the lifter pin 16 up and down, a carrier machine is provided. Receives an object to be heated such as the semiconductor wafer 29 from the semiconductor wafer 2
9 can be supported and heated while being separated from the heating surface 11a of the ceramic heater 10 by a predetermined distance. Further, instead of the lifter pin 16, a support pin (not shown) is provided on the heating surface of the ceramic heater, and the semiconductor wafer 29 is supported by the support pin while being separated from the heating surface of the ceramic heater 10 by a predetermined distance. It is also possible to heat. A temperature measuring element (not shown) to which a lead wire is connected is embedded in the bottomed hole 14 for measuring the temperature of the ceramic substrate 11.

FIG. 3 is a horizontal sectional view schematically showing another example of the ceramic heater of the present invention, and FIG. 4 is a partially enlarged sectional view of the ceramic heater shown in FIG.

As shown in FIG. 3, the ceramic heater 30
A resistance heating element 32 including eight circuits is formed inside a disk-shaped ceramic substrate 31. Each circuit to be the resistance heating element 32 is formed by connecting two metal wirings 32b through a plurality of elliptical conductive pad portions 32a.

The conductive pad portion 3 forming each circuit
2a are evenly arranged on the circumference of a circle having a concentric relationship with the ceramic substrate 31, and are connected via a metal wiring 32b formed of an arc. Therefore, the circuit as a whole constitutes an annular pattern.

A ring-shaped heating element non-forming region is provided between the eight circuits forming the resistance heating element 32.
A circular heating element non-forming region is also provided in the central portion.

Therefore, as a whole, the resistance heating element forming regions and the heating element non-forming regions are alternately formed from the outside to the inside, and these regions are formed in the size (diameter) and thickness of the ceramic substrate. The temperature of the heating surface can be made uniform by appropriately setting the temperature in consideration.

As shown in FIG. 4, the conductive pad portion 32a provided inside the ceramic substrate 31 has a rectangular cross section, and the metal wiring 32b also has a rectangular cross section. Further, a through hole 39 is formed immediately below the conductive pad portion 32a which is an end of the resistance heating element 32, and a bag hole 39a for exposing the through hole 39 is formed on the bottom surface 31b. An external terminal 33 is inserted in this and is joined with a brazing material or the like (not shown). For example, a socket (not shown) having a conductive wire is attached to the external terminal 33, and the conductive wire is connected to a power source or the like.

A bottomed hole 34 and a through hole 35 are formed in the ceramic heater 30, and a lifter pin 36 is inserted into the through hole 35. By moving the lifter pin 36 up and down, a carrier machine is provided. Receives an object to be heated such as the semiconductor wafer 29 from the semiconductor wafer 2
9 can be supported and heated while being separated from the heating surface 31a of the ceramic heater 30 by a predetermined distance. Further, instead of the lifter pin 36, a supporting pin (not shown) is provided on the heating surface of the ceramic heater, and the semiconductor wafer 29 is supported by the supporting pin while being separated from the heating surface of the ceramic heater 30 by a predetermined distance. It is also possible to heat. In the bottomed hole 34, a temperature measuring element (not shown) connected to a lead wire for measuring the temperature of the ceramic substrate 31 is embedded.

In the ceramic heater of the present invention, the circuit which becomes the resistance heating element is formed by connecting the metal wiring through the conductive pad portion. The total number of circuits is not particularly limited, but is preferably 4 to 10 when the diameter of the ceramic substrate is 210 (mm), and 7 to 7 when the diameter of the ceramic substrate is 300 (mm). It is preferably 20. If the total number of circuits is less than the above range, the total number of circuits of the resistance heating element with respect to the area of the heating surface of the ceramic heater is small, and the area to be heated in one circuit becomes too wide, so the amount of heat generated within one circuit varies. Is increased, and the temperature of the heating surface of the ceramic heater becomes uneven. on the other hand,
If the total number of circuits exceeds the above range, the manufacturing process of the ceramic heater becomes complicated, and it becomes difficult to easily control the temperature of the resistance heating element.

The pattern of the above circuit is shown in FIG.
Is not limited to the regular octagonal band-shaped pattern shown in FIG. 3 and the circular ring-shaped pattern shown in FIG. 3, for example, a regular polygonal banded pattern such as a regular dodecagon or a regular hexagon, or a spiral pattern. A pattern or the like can be used. In addition, these may be used in combination. It should be noted that, as in the circuit patterns shown in FIGS. 1 and 3, by forming the circuit in the outer peripheral portion of the ceramic substrate and the circuit in the inner peripheral portion different from each other, the outer peripheral portion of the ceramic heater in which the temperature tends to decrease With this, it becomes possible to perform temperature control so that there is no temperature difference with the inner peripheral portion. Furthermore, by making the pattern of the circuit formed on the outermost circumference a pattern that is divided in the circumferential direction, it becomes possible to perform fine temperature control on the outermost circumference of the ceramic heater where the temperature easily drops, and the ceramic heater heating It is possible to make the surface temperature uniform. Further, the circuit pattern divided in the circumferential direction is not limited to the outermost circumference of the ceramic substrate, and may be formed inside the ceramic substrate. The circuit pattern described above can be formed by combining the arrangement of the conductive pad portions and the shape of the metal wiring connecting the conductive pad portions in plan view.

It is desirable that the circuit is formed at a position of 60% or less in the thickness direction from the surface opposite to the heating surface. If it exceeds 60%, it is too close to the heating surface, so that the heat propagating in the ceramic substrate is not sufficiently diffused, and temperature variations occur on the heating surface.

It is also possible to provide a plurality of layers in which the above circuits are formed. In this case, it is desirable that the circuits of each layer have circuits formed in some layers so as to complement each other, and that the circuits are formed in any region when viewed from above the heating surface. As such a structure, for example,
An example is a structure in which they are arranged in a staggered pattern.

It is desirable that the conductive pad portions are arranged substantially evenly on the circumference of a circle having a concentric relationship with the ceramic substrate. By placing conductive pad portions substantially evenly on the circumference of a circle having a concentric circle with the ceramic substrate and connecting the metal wirings through the conductive pad portions, as described above, the ceramic substrate This is because the circuit in the outer peripheral portion and the circuit in the inner peripheral portion can be different circuits. As a result, it becomes possible to perform temperature control so that there is no temperature difference between the outer peripheral portion and the inner peripheral portion of the ceramic heater where the temperature tends to decrease.

The shape of the conductive pad portion in plan view is not particularly limited as long as the conductive pad portion can be connected by metal wiring. Examples of the shape of the conductive pad portion in plan view include a rectangle, a trapezoid, an ellipse, and a perfect circle.

It is desirable that the distance between the conductive pad portions constituting one circuit is 100 mm or less. 100 mm
This is because if it exceeds, the length of the metal wiring connecting the conductive pad portion becomes long, and the amount of change in the length of the metal wiring due to thermal expansion becomes large. As a result, a large thermal stress is generated, which may cause chipping or cracks in the ceramic substrate. The intervals between the conductive pad portions are preferably substantially equal, but can be set according to the pattern of the circuit to be formed and the like.

The area and thickness of the conductive pad portion are set in consideration of the material thereof, the number of metal wirings connecting the conductive pad portion, and the like. It is desirable that it is in the range. That is, the area of the conductive pad portion is preferably 1 to 200 mm ² . When it is less than 1 mm ² , it is difficult to connect the metal wiring with the conductive pad portion because the area is too small, and when it exceeds 200 mm ² , the area is too large and the resistance value in the conductive pad portion is large. Has decreased,
Cooling spots may occur. The thickness of the conductive pad portion is preferably 300 μm or less. This is because if the thickness exceeds 300 μm, the conductive pad portion is too thick, and the resistance value in the conductive pad portion is greatly reduced, which may cause a cooling spot.

It is desirable to adjust the resistance value of the conductive pad portion so that the conductive pad portion does not generate heat from the metal wiring when the temperature is raised. This is because if the conductive pad section generates heat from the metal wiring, a hot spot may be generated directly above the conductive pad section, and the temperature of the heating surface may become uneven.

The sectional shape of the metal wiring is not particularly limited, and examples thereof include a rectangle, a perfect circle, an ellipse, and a flat shape.

The shape of the metal wiring in plan view is not particularly limited as long as the metal wiring is not elongated as described above. For example, it may be a straight line as shown in FIG. As shown in FIG. 3, it may be a circular arc. Further, it may have a shape in which the bending line is repeated.

Next, the materials of the conductive pad portion and the metal wiring forming the circuit will be described. When forming the conductive pad portion, a conductor paste or foil is used.
The conductor paste is not particularly limited, but it is preferable that the conductor paste contains metal particles or a conductive ceramic for ensuring conductivity, and contains 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, and of these, noble metals (gold, silver, platinum, palladium) are more preferable. Also,
These may be used alone, but it is desirable to use two or more kinds in combination. This is because these metals are relatively difficult to oxidize and have a resistance value sufficient to generate heat. Examples of the conductive ceramics include carbides of tungsten and molybdenum. These may be used alone or in combination of two or more.

The particle size of these metal particles or conductive ceramic particles is preferably 0.1 to 100 μm. 0.1μ
If it is less than m and too fine, it is easily oxidized, while 100
This is because if it exceeds μm, it becomes difficult to sinter and the resistance value increases.

Even if the shape of the metal particles is spherical,
It may be flaky. When these metal particles are used, they may be a mixture of the above-mentioned spherical material and the above-mentioned scaly material. When the metal particles are flakes, or a mixture of spheres and flakes, it becomes easier to hold the metal oxide between the metal particles, and the adhesion between the conductive pad portion and the nitride ceramic, etc. Is assured and the resistance value can be increased, which is advantageous.

The resin used for the conductor paste is
For example, an epoxy resin, a phenol resin, etc. are mentioned. Examples of the solvent include isopropyl alcohol and the like. Examples of the thickener include cellulose and the like.

As described above, it is desirable that the conductive paste is formed by adding a metal oxide to the metal particles and sintering the conductive pad portion of the metal particles and the metal oxide. Thus, by sintering the metal oxide together with the metal particles, the nitride ceramic or the carbide ceramic, which is the ceramic substrate, can be brought into close contact with the metal particles.

Although the reason why the adhesion with the nitride ceramic or the carbide ceramic is improved by mixing the metal oxide is not clear, the surface of the metal particles or the surface of the nitride ceramic or the carbide ceramic is slightly oxidized. It is considered that the oxide film is formed by sintering and the oxide film is sintered through the metal oxide to be integrated with each other, and the metal particles and the nitride ceramic or the carbide ceramic adhere to each other.

Examples of the above-mentioned metal oxides include oxidation.
Lead, zinc oxide, silica, boron oxide (B _TwoO_Three), Al
Selected from the group consisting of Mina, Yttria and Titania
At least one 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 conductive pad portion.

The above lead oxide, zinc oxide, silica, boron oxide (B ₂ O ₃ ), alumina, yttria, and titania are in a weight ratio when the total amount of metal oxides is 100 parts by weight. 1-10, silica 1-30, boron oxide 5-50, zinc oxide 20-70, alumina 1
-10, yttria is 1-50, and titania is 1-50, and it is desirable that the total is adjusted not to exceed 100 parts by weight. By adjusting the amounts of these oxides within these ranges, it is possible to improve the adhesion, particularly with the nitride ceramics. 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.

Further, as described above, it is possible to use a foil when forming the conductive pad portion. Examples of the foil include nickel foil, metal foil such as stainless steel foil, foil made of noble metal such as gold, silver, platinum and palladium, foil made of refractory metal such as tungsten and molybdenum, and tungsten and molybdenum. Examples include foils made of the above-mentioned carbides.

When forming the above-mentioned metal wiring, an elongated foil or wire can be used. As the elongated foil, the same foil as that described above can be used.
The elongated foil can be obtained by forming it into a shape to which the conductive pad portion can be connected, by etching or the like, or by cutting it with scissors or the like.

As the wire, for example, a wire made of nickel or stainless steel, gold, silver, platinum,
Examples thereof include a wire made of a noble metal such as palladium, a wire made of a high melting point metal such as tungsten and molybdenum wire, and a wire made of a carbide of tungsten and molybdenum.

Above all, it is desirable to use, as the metal wiring, an elongated foil or wire made of tungsten and / or a carbide of tungsten, that is, tungsten carbide. This is because tungsten and tungsten carbide have high melting points, and thus wire breakage due to melting is unlikely to occur. Further, since disconnection due to melting is unlikely to occur, the resistance value can be increased by thinning (thinning) the metal wiring.

Further, as shown in FIG. 1, in order to secure the connection between the conductive pad portion and the metal wiring, for example, a conductive adhesive layer made of a paste adhesive containing metal particles is used to interpose the metal. The wiring may be connected to the conductive pad portion. As the adhesive, the same composition as the above-mentioned conductor paste can be used.

The area resistivity when the resistance heating element composed of the above-mentioned conductive pad portion and metal wiring is formed is
0.1 mΩ to 10 Ω / □ is preferable. Area resistivity is 0.
If it is less than 1 mΩ / □, the width of the metal wiring or the like must be made extremely thin to be about 0.1 to 1 mm in order to secure the heat generation amount. Or the resistance value fluctuates, and the area resistivity is 10Ω.
If it exceeds / □, the width of metal wiring, etc. must be increased.
This is because the amount of heat generation cannot be secured, and as a result, the degree of freedom in designing the pattern of the circuit that becomes the resistance heating element decreases, making it difficult to make the temperature of the heating surface uniform.

The resistance heating element 12 needs a terminal for connecting to a power source, and this terminal is attached to the resistance heating element 12 via solder. A part of the resistance heating element may be exposed on the surface and the terminal may be connected.A through hole for connecting the resistance heating element is provided in the terminal part, and the terminal is connected and fixed to this through hole. Good. Examples of the connection terminal include an external terminal 13 made of Kovar.

When connecting the connection terminals, the solder is
Alloys such as silver-lead, lead-tin, 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 the solder connection.

In the ceramic heater of the present invention, the diameter of the ceramic substrate is preferably 200 mm or more. This is because the larger the diameter of the ceramic heater, the more easily the temperature of the semiconductor wafer, which is the object to be heated, becomes nonuniform during heating, so that the configuration of the present invention functions effectively. In addition, a large-diameter semiconductor wafer can be placed on the substrate having such a large diameter. The diameter of the ceramic substrate is preferably 12 inches (300 mm) or more. This is because it will become the mainstream of next-generation semiconductor wafers.

The thickness of the ceramic substrate of the hot plate unit of the present invention is preferably 25 mm or less. This is because if the thickness of the ceramic substrate exceeds 25 mm, the temperature followability deteriorates. The thickness is preferably 0.5 mm or more. 0.5 mm
When the thickness is thinner, the strength itself of the ceramic substrate is lowered and the ceramic substrate is easily damaged. More preferably, more than 1.5 and 5 m
m or less. When it is thicker than 5 mm, heat is less likely to propagate and the efficiency of heating tends to decrease.
If the thickness is 5 mm or less, the heat propagating in the ceramic substrate is not sufficiently diffused, which may cause temperature variations on the heating surface, and the strength of the ceramic substrate may be reduced and the ceramic substrate may be damaged.

In the ceramic heater 10 of the present invention,
The ceramic substrate 11 is provided with a bottomed hole 14 from the side opposite to the heating surface 11 a toward the heating surface 11 a, and the bottom of the bottomed hole 14 is relatively heated with respect to the resistance heating element 12.
It is desirable that the temperature measuring element (not shown) such as a thermocouple be provided in the bottomed hole 14 so as to be formed close to a.

The distance between the bottom of the bottomed hole 14 and the heating surface 11a is preferably 0.1 mm to 1/2 of the thickness of the ceramic substrate. This is because the temperature measurement location is closer to the heating surface 11a than the resistance heating element 12, and it becomes possible to measure the temperature of the semiconductor wafer more accurately.

If the distance between the bottom of the bottomed hole 14 and the heating surface 11a is less than 0.1 mm, heat is radiated, and a temperature distribution is formed on the heating surface 11a. This is because the body is likely to be affected by the temperature, the temperature cannot be controlled, and the temperature distribution is formed on the heating surface 11a.

The diameter of the bottomed hole 14 is 0.3 mm to 5 mm.
Is desirable. This is because if it is too large, the heat dissipation becomes large, and if it is too small, the workability deteriorates and the distance to the heating surface 11a cannot be made uniform.

As shown in FIG. 1, it is preferable that a plurality of 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 heated surface can be measured.

As the temperature measuring element, for example, a thermocouple,
Examples include platinum resistance temperature detectors and thermistors. Further, as the thermocouple, for example, JIS-C-1602 (1
980), K type, R type, B type, S type
Examples include type, E type, J type, T type thermocouples, and of these, K type thermocouples are preferable.

The size of the joint portion of the thermocouple is preferably equal to or larger than the diameter of the strand, and is 0.5 mm or less. This is because if the joint is large, the heat capacity becomes large and the responsiveness deteriorates. It is difficult to make the diameter smaller than the diameter of the strand.

The temperature measuring element may be bonded to the bottom of the bottomed hole 14 by using gold solder, silver solder or the like.
After it is inserted into the container, it may be sealed with a heat resistant resin, or both may be used together. Examples of the heat resistant resin include thermosetting resins, particularly epoxy resins, polyimide resins, bismaleimide-triazine resins, and the like. These resins may be used alone or in combination of two or more.

As the above-mentioned gold braze, 37 to 80.5% by weight Au-63 to 19.5% by weight Cu alloy, 81.5 to 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. Examples of silver wax include Ag
A Cu-based material can be used.

The ceramic forming the ceramic heater of the present invention is preferably a nitride ceramic or a carbide ceramic. Nitride ceramics and carbide ceramics have a thermal expansion coefficient smaller than that of metals and a mechanical strength much higher than that of metals, so even if the thickness of the ceramic substrate is reduced, it will not warp or distort due to heating. .
Therefore, the ceramic substrate can be made thin and light. Furthermore, the thermal conductivity of the ceramic substrate is high,
Since the ceramic substrate itself is thin, the surface temperature of the ceramic substrate quickly follows the temperature change of the resistance heating element. That is, the surface temperature of the ceramic substrate can be controlled by changing the temperature of the resistance heating element by changing the voltage and current values.

Examples of the above-mentioned nitride ceramics include:
Examples thereof include aluminum nitride, silicon nitride, boron nitride, titanium nitride and the like. These may be used alone or 2
You may use together 1 or more types.

Examples of the carbide ceramics include silicon carbide, zirconium carbide, titanium carbide, tantalum carbide, tungsten carbide and the like. These may be used alone or in combination of two or more.

Of these, aluminum nitride is most preferable. The highest thermal conductivity of 180 W / mK,
This is because the temperature followability is excellent. Further, the ceramic substrate may contain a sintering aid. Examples of the sintering aid include alkali metal oxides, alkaline earth metal oxides, rare earth oxides, and the like. Among these sintering aids, CaO, Y ₂ O ₃ , Na ₂ O, Li
₂ O and Rb ₂ O are preferred. As for the content of these,
0.1 to 20% by weight is preferable. It may also contain alumina. The porosity of the ceramic substrate is 0.
Alternatively, it is preferably 5% or less. This is because it has high mechanical strength and excellent insulating properties.

Further, the ceramic substrate of the present invention contains carbon, and the content thereof is preferably 200 to 5000 ppm. This is because the electrodes can be hidden and black body radiation can be easily used.

The ceramic substrate has a brightness of JI.
The value based on the regulation of S Z 8721 is preferably N6 or less. This is because those having such brightness are excellent in radiant heat amount and concealing property. Where N of lightness
Sets the ideal black lightness to 0 and the ideal white lightness to 1
It is set to 0, and each color is divided into 10 so that the perception of the brightness of the color becomes equal between the brightness of black and the brightness of white, and is represented by symbols N0 to N10. Then, the actual measurement is performed by comparing with the color patches corresponding to N0 to N10. In this case, the first decimal place is 0 or 5.

When an electrostatic electrode layer is formed inside the ceramic substrate of the present invention, the ceramic substrate functions as an electrostatic chuck. In this case, the ceramic substrate that constitutes this electrostatic chuck has substantially the same configuration as the above-mentioned ceramic heater, except that an electrostatic electrode is formed. FIG. 5 is a vertical cross-sectional view schematically showing an embodiment of the electrostatic chuck according to the present invention, and FIG. 6 is a sectional view of the electrostatic chuck shown in FIG.
It is a line sectional view.

In this electrostatic chuck 20, a resistance heating element 25 composed of a conductive pad portion 25a and a metal wiring 25b is formed inside a disk-shaped ceramic substrate 21 like the above-mentioned ceramic heater. An electrostatic electrode layer composed of a chuck positive electrode electrostatic layer 22 and a chuck negative electrode electrostatic layer 23 is embedded inside the ceramic substrate 21, and a thin ceramic layer 24 (hereinafter, A ceramic dielectric film) is formed. A semiconductor wafer 29 is placed on the electrostatic chuck 20 and grounded. The ceramic dielectric film 24
The thickness is preferably 5 to 5000 μm. This is because the semiconductor wafer 29 is sucked with a sufficient suction force while keeping the withstand voltage high.

As shown in FIG. 6, the chuck positive electrode electrostatic layer 22 is composed of a semicircular arc portion 22a and a comb tooth portion 22b.
The chuck negative electrode electrostatic layer 23 is also composed of a semi-circular arc portion 23a and a comb tooth portion 23b. The chuck positive electrode electrostatic layer 22 and the chuck negative electrode electrostatic layer 23 are the comb tooth portions 22b and 2b.
The chuck positive electrode electrostatic layer 22 and the chuck negative electrode electrostatic layer 23 are connected to the positive side and the negative side of a DC power source, respectively, and the DC voltage V ₂ is Is applied.

Further, in order to control the temperature of the semiconductor wafer 29 inside the ceramic substrate 21, as shown in FIG. 1, the conductive pad portion 25a and the metal wiring 25b are provided.
A resistance heating element 25 having a concentric shape in a plan view is provided, and external terminals are connected and fixed to both ends of the resistance heating element 25, and a voltage V ₁ is applied. Although not shown in FIGS. 5 and 6, the ceramic substrate 21 has a bottomed hole for inserting a temperature measuring element and a lifter pin penetration for inserting a lifter pin for supporting and vertically moving the silicon wafer 29. And holes are formed (see FIGS. 1 and 2).

When the electrostatic chuck 20 is made to function, the chuck positive electrode electrostatic layer 22 and the chuck negative electrode electrostatic layer 23 are used.
A DC voltage V ₂ is applied to and. As a result, the semiconductor wafer 29 is adsorbed and fixed to these electrodes through the ceramic dielectric film 24 by the electrostatic action of the chuck positive electrode electrostatic layer 22 and the chuck negative electrode electrostatic layer 23. . In this way, the semiconductor wafer 29 is attached to the electrostatic chuck 2
After being fixed on the surface of the semiconductor wafer 29, CVD is performed on the semiconductor wafer 29.
And various other processes are performed.

Examples of the electrostatic electrode include a sintered body of metal or conductive ceramic, a metal foil, and the like.
The metal sintered body is preferably made of at least one selected from tungsten and molybdenum. The metal foil is also preferably made of the same material as the metal sintered body. This is because these metals are relatively hard to oxidize and have sufficient conductivity as electrodes. As the conductive ceramic, at least one selected from carbides of tungsten and molybdenum can be used.

7 and 8 are horizontal sectional views schematically showing electrostatic electrodes in another electrostatic chuck.
In the electrostatic chuck 40 shown in FIG. 7, a semicircular chuck positive electrode electrostatic layer 42 and a chuck negative electrode electrostatic layer 43 are formed inside the ceramic substrate 21, and in the electrostatic chuck 60 shown in FIG. The chuck positive electrode electrostatic layers 62a and 62b and the chuck negative electrode electrostatic layers 63a and 63b each having a shape obtained by dividing a circle into four are formed inside. Further, the two positive electrode electrostatic layers 62a and 62b and the two chuck negative electrode electrostatic layers 63a and 63b are formed so as to intersect with each other. In the case of forming an electrode having a shape in which a circular electrode is divided, the number of divisions is not particularly limited and may be 5 or more, and the shape thereof is not limited to a fan shape.

Further, the ceramic substrate of the present invention functions as a chuck top plate for a wafer prober by providing a chuck top conductor layer on the surface and internally providing a guard electrode, a ground electrode and the like.

Next, a method of manufacturing the ceramic heater for semiconductor manufacturing / inspecting apparatus of the present invention will be described. A method of manufacturing a ceramic heater for a semiconductor manufacturing / inspecting device according to the present invention comprises forming a plurality of conductive layers on one green sheet by bonding a foil or screen-printing a conductor paste, Conductor placement step of placing and fixing one or more conductive wires and / or elongated foils so as to connect the conductive layers, and a green sheet on which the conductive layers and wires and / or foils are fixed And a plurality of other green sheets to form a green sheet laminate, and a firing step of degreasing and firing the obtained green sheet laminate. It is a method of manufacturing a ceramic heater for a manufacturing / inspection apparatus. In the following description, the method for manufacturing the ceramic heater for semiconductor manufacturing / inspection equipment will be simply referred to as the method for manufacturing the ceramic heater.

The above-described ceramic heater of the present invention can be obtained by the method of manufacturing a ceramic heater of the present invention. As an example of the method for manufacturing the ceramic heater of the present invention, a method for manufacturing the ceramic heater 10 (see FIGS. 1 and 2) will be described with reference to FIG.

(1) Green Sheet Manufacturing Step First, a ceramic powder such as a nitride ceramic is mixed with a binder, a solvent and the like to prepare a paste, and the green sheet 50 is manufactured using this.

Aluminum nitride or the like may be used as the above-mentioned ceramic powder of nitride or the like, and if necessary, a sintering aid such as yttria or a compound containing Na or Ca may be added. Further, the binder is preferably at least one selected from acrylic binders, ethyl cellulose, butyl cellosolve, and polyvinyl alcohol.

Further, the solvent is preferably at least one selected from α-terpineol and glycol. The paste obtained by mixing these is molded into a sheet by the doctor blade method to produce a green sheet. The thickness of the green sheet is preferably 0.1 to 5 mm. Also, the green sheet 50 has through holes 19
A through hole that will become

(2) Conductor Arranging Step A plurality of conductive layers 120 are formed on the green sheet 50 in the first step by adhering a foil or screen-printing a conductive paste. In the case of adhering a foil, the foil may be, for example, a nickel foil, a metal foil such as a stainless steel foil, a foil made of a noble metal such as gold, silver, platinum or palladium, or a foil made of a refractory metal such as tungsten or molybdenum. Alternatively, a foil made of a carbide such as tungsten or molybdenum can be used. The foil can be obtained by cutting with a scissor or the like into a predetermined shape such as a rectangle or an ellipse.

Then, the foil formed into a predetermined shape is adhered onto one green sheet 50 so as to have a predetermined arrangement to form a plurality of conductive layers 120. The foil may be adhered by directly placing it on one green sheet 50. For example, a resin film or the like may be adhered to the foil, and the foil may be attached via the resin film or the like. It may be adhered onto one green sheet 50.

When the conductor paste is screen-printed, the conductor layer 12 is screen-printed with a conductor paste containing a metal paste or a conductive ceramic on one green sheet 50 so that the conductor layer 12 has a predetermined shape and arrangement.
Form 0. The conductor paste contains metal particles or conductive ceramic particles.

The average particle size of the tungsten particles or molybdenum particles contained in the conductor paste is 0.1-5.
μm is preferred. The average particle size is less than 0.1 μm,
If it exceeds 5 μm, it is difficult to print the conductor paste. Examples of such a conductor paste include, for example, 85 to 87 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; and α-terpineol,
At least one solvent selected from glycol is 1.5
The composition (paste) which mixed 10 weight part is mentioned.

As described above, the foil may be adhered, or
Alternatively, when the conductive layer is formed by screen-printing a conductive paste, it is desirable that the plurality of conductive layers are arranged substantially evenly on the circumference of a circle assumed on the one green sheet.

Next, one or a plurality of wires 121 are placed and fixed so as to be connected through the plurality of conductive layers 120. An elongated foil may be used instead of the wire 121, and the wire and the elongated foil may be used together. Examples of the wire 121 include a wire made of nickel or stainless steel, a wire made of a noble metal such as gold, silver, platinum or palladium, a wire made of a refractory metal such as tungsten or molybdenum wire, or a carbide of tungsten or molybdenum. It is possible to use a wire made of When the elongated foil is used, the same foil as the foil described above can be used. Usually, the foil is often rectangular,
This can be used by cutting it into an elongated shape.

Among the above, the wires 121 and /
Or, as the elongated foil, tungsten, and / or
Alternatively, it is desirable to use an elongated foil or wire made of tungsten carbide, that is, tungsten carbide.

The wire 121 and / or the elongated foil does not necessarily have to be linear as shown in FIG. 1. For example, as shown in FIG. Etc. may be formed into a predetermined shape. Also,
In order to secure the connection between the conductive layer 120 and the wire 121,
For example, the wire 121 can be fixed to the conductive layer 120 with a paste-like adhesive 122 containing metal particles or the like.

A conductive paste filling layer 190 for the through hole 19 is formed in the through hole of the one green sheet 50 on which the conductive layer 120 is formed.

(3) Green Sheet Laminating Step A plurality of other green sheets 50 'are laminated on the upper and lower sides of the green sheet 50 to which the conductive layer 120 and the wires 121 are fixed to form a green sheet laminated body (FIG. 9). (A)
reference). At this time, the green sheet 50 to which the conductive layer 120 and the wire 121 are fixed is laminated so that the green sheet 50 is located at a position of 60% or less from the bottom with respect to the thickness of the green sheet laminate. Specifically, the number of stacked green sheets on the upper side is preferably 20 to 50, and the number of stacked green sheets on the lower side is preferably 5 to 20.

(4) Firing step The green sheet laminate is degreased and fired to sinter the green sheets 50 and 50 ', and the metal particles and ceramic particles contained in the conductive layer 120, the wire 121 and the like. The heating temperature is 1000 to 200
The temperature is preferably 0 ° C., and the pressure applied is preferably 10 to 20 MPa. The heating is performed in an inert gas atmosphere. As the inert gas, for example, argon, nitrogen or the like can be used. As a result, the conductive layer 120 becomes the conductive pad portion 12a, the wire 121 becomes the metal wiring 12b, and the conductive pad portion 12a and the metal wiring 12b are provided therein.
It is possible to obtain a sintered body (ceramic substrate 11) on which the resistance heating element 12 including is formed (see FIG. 9B).

Next, the obtained ceramic substrate 11 has a bottomed hole 14 for embedding a temperature measuring element such as a thermocouple, a through hole 19 for connecting the resistance heating element 12 to the external terminal 13, and a blind hole 18. And so on. (See FIG. 9 (c))

The step of forming the bottomed hole 14 may be performed on the green sheet laminate, but is preferably performed on the sintered body (ceramic substrate 11). This is because there is a risk of deformation during the sintering process.

The bottomed hole 14 can be formed by performing a blasting process such as sandblasting after the surface is polished. Further, the external terminal 13 is connected to the through hole 19 for connecting with the internal resistance heating element 12, and heating and reflow are performed. The heating temperature is preferably 200 to 500 ° C.

Further, a thermocouple (not shown) as a temperature measuring element is attached to the bottomed hole 14 with silver solder, gold solder, etc., and sealed with a heat resistant resin such as polyimide to manufacture the ceramic heater 10. The process ends (see FIG. 9D).

The method for manufacturing the ceramic heater according to the present invention has been described above. However, by adding the step of providing the electrostatic electrode inside the ceramic substrate to the method for manufacturing the ceramic heater according to the present invention, the electrostatic heater according to the present invention can be obtained. A chuck manufacturing method can be used. Further, by adding a step of providing a chuck top conductor layer on the surface of a ceramic substrate and internally providing a guard electrode or a ground electrode to the method for manufacturing a ceramic heater of the present invention, the chuck used in the wafer prober according to the present invention. The method of manufacturing the top plate can be used.

[0118]

EXAMPLES The present invention will now be described in more detail with reference to examples.

(Example 1) Production of ceramic heater (see FIGS. 1, 2 and 9) (1) 100 parts by weight of aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 0.6 μm), 4 parts by weight of alumina, acrylic Using a paste prepared by mixing 11.5 parts by weight of a resin binder, 0.5 parts by weight of a dispersant, and 53 parts by weight of an alcohol composed of 1-butanol and ethanol, the paste was molded by the doctor blade method to give a thickness of 0.47 mm. The green sheet of was produced.

(2) Next, this green sheet is heated to 80 ° C.
After drying for 5 hours, the portion to be the through hole 19 was provided by punching.

(3) Tungsten metal foil (thickness: 10
0 μm, manufactured by Tokyo Tungsten Co., Ltd.) was used to cut a plurality of rectangular or trapezoidal foils (area: 100 mm ² ) as shown in FIG. Average particle size 3 μm
100 parts by weight of the tungsten particles, 1.9 parts by weight of the acrylic binder, 3.7 parts by weight of the α-terpineol solvent and 0.2 parts by weight of the dispersant were mixed to prepare a conductor paste B.

A cellophane resin film with an adhesive tape (manufactured by Nitto Denko Corporation) is adhered to the plurality of foils, and the plurality of foils are adhered to the green sheet through the resin film, whereby the conductive layer 120 is formed. Was formed. The plurality of foils were arranged substantially evenly on the circumference of the circle assumed on the green sheet.

(4) Tungsten wire (diameter: 30
0 μm, manufactured by Nitto Denko Co., Ltd.) was cut into a predetermined length and placed and fixed so as to connect the plurality of conductive layers. In addition,
Each conductive layer was connected by two wires. The two wires were fixed to the conductive layer using a paste-like conductive adhesive containing tungsten carbide particles and the like. At this time, the length of the wire was 50 mm. Further, the portion to be the through hole 19 for connecting the external terminal 13 was filled with the conductive paste B to form the filling layer 190.

On the green sheet which has been subjected to the above treatment, 37 green sheets which have not been subjected to the above treatment are laminated on the upper side (heating surface), and 13 sheets are laminated on the lower side.
A laminate was formed by pressure bonding with a pressure of 8 MPa (FIG. 5).
(See (a)).

(5) Next, the obtained laminated body was degreased in nitrogen gas at 600 ° C. for 5 hours, at 1890 ° C. and a pressure of 15M.
Hot pressing was performed at Pa for 10 hours to obtain a ceramic plate-like body having a thickness of 3 mm. This was cut into a disk shape of 230 mm, and as shown in FIG. 1, a ceramic plate body having a resistance heating element 12 composed of a conductive pad portion 12a and a metal wiring 12b was formed (see FIG. 5B).

(6) Next, a mask is placed on the ceramic plate obtained in (5), and a bottomed hole 14 for inserting a temperature measuring element is provided on the surface by blasting with SiC or the like.
In addition, a blind hole 18 having a diameter of 5 mm and a depth of 0.5 mm was formed by drilling.

(7) Next, the portion in which the through hole 19 is formed is cut out to form a bag hole 18 (see FIG. 5C), and a gold solder made of Ni-Au is used for the bag hole 18. Reflowing was performed by heating at 700 ° C. and the external terminal 13 made of Kovar was connected (see FIG. 5D). Further, a thermocouple (not shown) for temperature control was embedded in the bottomed hole 14 to obtain the ceramic heater 10 of the present invention.

Example 2 Manufacturing of Ceramic Heater (See FIGS. 3 and 4) (1) 100 parts by weight of aluminum nitride powder (produced by Tokuyama Corporation, average particle size: 0.6 μm), 4 parts by weight of alumina, acrylic resin binder A green sheet having a thickness of 0.47 mm is formed by a doctor blade method using a paste in which 11.5 parts by weight, 0.5 parts by weight of a dispersant, and 53 parts by weight of an alcohol composed of 1-butanol and ethanol are mixed. Was produced.

(2) Next, this green sheet is heated to 80 ° C.
After drying for 5 hours, the portion to be the through hole 39 was provided by punching.

(3) A conductor obtained by mixing 100 parts by weight of tungsten carbide particles having an average particle diameter of 1 μm, 3.0 parts by weight of an acrylic binder, 3.5 parts by weight of an α-terpineol solvent and 0.3 part by weight of a dispersant. Paste A was prepared.
A conductor 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 part by weight of a dispersant.

By conducting screen printing of the conductor paste A on the green sheet, an elliptical conductive layer (area: 100 mm ² , thickness: 30 μm) was formed as shown in FIG. The conductive layer was printed on the circumference of a circle assumed on the green sheet so as to be substantially even.

(4) Tungsten foil (thickness: 100
μm), as shown in FIG. 3, arc shape (width: 1 mm)
After molding to obtain an elongated foil, it was placed and fixed so as to connect the plurality of conductive layers. In addition, each conductive layer was connected with two thin foils. At this time, the elongated foil had a length of 50 mm. Further, the portion to be the through hole 39 for connecting the external terminal 33 was filled with the conductor paste B to form a filling layer.

On the green sheet which has been subjected to the above treatment, 37 green sheets which have not been subjected to the above treatment are laminated on the upper side (heating surface), and 13 sheets are laminated on the lower side.
A pressure was applied at a pressure of 8 MPa to form a laminate.

(4) Next, the laminated body thus obtained was degreased in nitrogen gas at 600 ° C. for 5 hours, and at 1890 ° C. and a pressure of 15M.
Hot pressing was performed at Pa for 10 hours to obtain a ceramic plate-like body having a thickness of 3 mm. This was cut into a 230 mm disk shape to obtain a ceramic plate-like body having a resistance heating element 32 composed of a conductive pad portion 32a and a metal wiring 32b as shown in FIG.

(5) Next, a mask is placed on the ceramic plate obtained in (4), and a bottomed hole 34 for inserting a temperature measuring element is provided on the surface by blasting with SiC or the like.
In addition, a blind hole 18 having a diameter of 5 mm and a depth of 0.5 mm was formed by drilling.

(6) Next, the portion in which the through hole 39 is formed is cut out to form a bag hole 39a, and this bag hole 3 is formed.
A gold solder made of Ni-Au was used for 9a, and reflowed by heating at 700 ° C. to connect the external terminal 33 made of Kovar. Further, a thermocouple (not shown) for temperature control was embedded in the bottomed hole 34 to obtain the ceramic heater 30 of the present invention.

Comparative Example 1 Manufacturing of Ceramic Heater (See FIG. 10) (1) Aluminum Nitride Powder (Average Particle Size: 0.6 μm)
100 parts by weight, yttria (average particle size: 0.4 μm) 4
A composition comprising 1 part by weight, 12 parts by weight of an acrylic binder and alcohol was spray-dried to produce a granular powder.

(2) Next, this granular powder was put into a mold and molded into a flat plate to obtain a green molded body (green).

(3) Next, this green body is treated at 1800 ° C.
It was hot pressed at a pressure of 20 MPa to obtain an aluminum nitride plate-shaped body having a thickness of 3 mm. Next, a disc body having a diameter of 230 mm was cut out from this plate body to obtain a ceramic plate body (ceramic substrate 71). This ceramic substrate 71 was drilled to form a bottomed hole (not shown) for embedding a thermocouple.

Furthermore, on the surface of the ceramic substrate 71, S
By blasting with iC or the like, as shown in FIG. 10, eight grooves 74 (depth: 1 mm, width: 1 mm) having an annular shape in plan view were formed.

A coil 7 made of a nichrome wire is provided in the groove 74.
2, the end portion 73 of the coil 72 is connected to a power source (not shown) through a lead wire 77, and the ceramic heater 70
Was discontinued.

(Comparative Example 2) Manufacture of ceramic heaters (see Fig. 11)

(1) A green sheet was prepared in the same manner as in Example 1, and the through holes were punched. Then, the tungsten wire 82 used in Example 1 was placed on the green sheet. As shown in FIG. 11, twelve wires 82 were placed so as to form a concentric circuit.

On the green sheet after the above treatment, 37 green sheets not subjected to the above treatment were laminated on the upper side (heating surface) and 13 sheets on the lower side, and were laminated at 130 ° C.
A pressure was applied at a pressure of 8 MPa to form a laminate. afterwards,
The same process as in Example 1 was performed to obtain a ceramic heater 80.

Comparative Example 3 Manufacturing of Ceramic Heater (See FIG. 12) (1) In the same manner as in Comparative Example 1, a ceramic substrate 91 having a diameter of 230 mm was produced. Then, the ceramic substrate 91
Then, a conductor paste layer was formed by screen printing. The print pattern was a spiral pattern as shown in FIG. The conductor paste includes Ag 48% by weight, Pt 21% by weight, SiO ₂ 1.0% by weight, B ₂ O ₃
2.2 wt%, ZnO 4.1 wt%, PbO 3.4 wt%, ethyl acetate 3.4 wt%, butyl carbitol 1
A composition having a composition of 7.9% by weight was used. This conductor paste was an Ag-Pt paste, and the silver particles had an average particle size of 4.5 μm and were flaky. The Pt particles were spherical with an average particle diameter of 0.5 μm.

(2) Further, after forming the conductor paste layer of the heating element pattern, the ceramic substrate 51 is heated and fired at 780 ° C. to sinter Ag and Pt in the conductor paste and bake it on the ceramic substrate 91. The resistance heating element 92 was formed. The resistance heating element 92 has a thickness of 5
It was formed so as to have a width of 2.4 mm and an area resistivity of 7.7 mΩ / □.

(3) Nickel sulfate 80 g / l, sodium hypophosphite 24 g / l, sodium acetate 12 g / l,
The ceramic substrate 91 prepared in (5) above was immersed in an electroless nickel plating bath consisting of an aqueous solution having a concentration of 8 g / l of boric acid and 6 g / l of ammonium chloride, and a thickness of 1 μm was formed on the surface of the resistance heating element 92 of silver-lead. Metal coating layer (nickel layer)
520 was deposited.

(4) Next, a silver-lead solder paste (manufactured by Tanaka Kikinzoku Co., Ltd.) is printed by screen printing on the portion where the external terminal 93 for securing the connection with the power source is mounted, and the solder layer (not shown). Form). Next, an external terminal 93 made of Kovar is placed on the solder layer and heated and reflowed at 420 ° C., the external terminal 93 is attached to the surface of the resistance heating element 92, and a thermocouple for controlling temperature (see FIG. (Not shown) was sealed with polyimide to obtain a ceramic heater 90.

Comparative Example 4 Manufacturing of Ceramic Heater (See FIG. 13) A ceramic heater 500 was manufactured in substantially the same manner as in Comparative Example 3, but the pattern of the resistance heating element 52 had a wide width as shown in FIG. The low resistance region 52a and the narrow high resistance region 52b are used.

The ceramic heaters of Examples 1 and 2 and Comparative Examples 1 to 4 were evaluated by the following method. The results are shown in Table 1.

[0151]Evaluation methods (1) In-plane temperature uniformity during steady state After heating the ceramic heater to 400 ° C,
The maximum temperature on the heating surface of the ceramic heater
The temperature and the minimum temperature were measured, and the temperature difference was calculated.

(2) Heat shock test The ceramic heater was heated to 400 ° C. and then dropped into water. Then, the presence or absence of cracks in the ceramic substrate was evaluated by visual observation.

[0153]

[Table 1]

As shown in Table 1, the ceramic heaters according to Examples 1 and 2 have a uniform in-plane temperature of the heating surface as compared with the ceramic heaters according to Comparative Examples 1, 3 and 4. It was

In the ceramic heaters according to Examples 1 and 2, commercially available wires and metal foils, that is, wires and metal foils previously formed in a predetermined shape (thickness) are used as the metal wiring. Therefore, it is considered that the variation in the resistance value was reduced and the temperature of the heating surface could be made uniform.

On the other hand, the ceramic heater 7 according to Comparative Example 1
When 0 was visually observed, the coil 72 protruded from the groove 74 or was distorted in the groove 74, and the coil 72 was displaced. It is considered that such misalignment occurs due to impact during use, thermal expansion due to repeated temperature increase and temperature decrease, and as a result, the temperature of the heating surface becomes non-uniform.

The thickness of the resistance heating element 92 of the ceramic heater 90 according to Comparative Example 3 was measured with a laser displacement meter (manufactured by Keyence Corporation). As a result, the thickness of the resistance heating element set at the time of manufacture was 5 μm, but actually it was 5.05 μm. It is considered that this is because the resistance heating element was formed by screen-printing the conductor paste, so that the thickness varied depending on the printing direction and the like. As a result, it is considered that the resistance value of the resistance heating element varied and the temperature of the heating surface became uneven.

In the ceramic heater 500 according to Comparative Example 4, heat generation was observed even in the wide low resistance region 52a of the resistance heating element 52, and the heat generating portion was formed between the uniformly arranged hot spots formed by the low resistance region 52b. Is present, and it is considered that temperature variations have occurred.

Further, in all of the ceramic heaters of Examples 1 and 2 and Comparative Example 2, the resistance heating element was formed inside the ceramic substrate, but Comparative Example 2
Only the ceramic heater according to (4) had cracks.
The resistance heating elements of the ceramic heater according to Examples 1 and 2 are
It is formed by connecting a metal wiring having a short length through a conductive pad portion. Therefore, it is considered that the amount of change in the length of the metal wiring due to the thermal expansion is reduced, the thermal stress due to the thermal expansion is reduced, and the ceramic substrate is not cracked.

On the other hand, the resistance heating element of the ceramic heater according to Comparative Example 2 is formed of a long wire. Therefore, it is considered that the amount of change in the length of the wire due to the thermal expansion becomes small, the thermal stress due to the thermal expansion becomes large, and the ceramic substrate is cracked. Further, the ceramic heater according to Comparative Example 1 also had cracks. This is because when the coil 72 protrudes from the groove 74 or is distorted in the groove 74 and the coil 72 is displaced, It is considered that the stress was accumulated in the cracks and the cracks were generated by releasing the accumulated stress at once at the time of cooling.

[0161]

According to the ceramic heater for semiconductor manufacturing / inspecting apparatus of the present invention, the circuit serving as the resistance heating element is not displaced due to thermal stress, and the ceramic substrate is free from cracks or cracks. It never happens. Further, by using a wire or foil that has been formed in a predetermined shape (thickness) in advance as the metal wiring, it is possible to suppress variations in the resistance value of the resistance heating element and make the temperature of the heating surface uniform. be able to.

Further, according to the method for manufacturing a ceramic heater for a semiconductor manufacturing / inspecting apparatus of the present invention, the above-described ceramic heater for a semiconductor manufacturing / inspecting apparatus of the present invention can be manufactured. As a result, it is possible to suppress variations in the resistance value of the resistance heating element, and it is possible to make the temperature of the heating surface of the ceramic heater for semiconductor manufacturing / inspection equipment uniform.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view schematically showing an example of a ceramic heater of the present invention.

FIG. 2 is a partially enlarged sectional view schematically showing a part of the ceramic heater shown in FIG.

FIG. 3 is a horizontal sectional view schematically showing another example of the ceramic heater of the present invention.

4 is a partially enlarged cross-sectional view schematically showing a part of the ceramic heater shown in FIG.

FIG. 5 is a sectional view schematically showing an example of an electrostatic chuck according to the present invention.

FIG. 6 is a horizontal cross-sectional view schematically showing the shape of an electrostatic electrode that constitutes the electrostatic chuck according to the present invention.

FIG. 7 is a horizontal cross-sectional view schematically showing the shape of an electrostatic electrode that constitutes the electrostatic chuck according to the present invention.

FIG. 8 is a horizontal cross-sectional view schematically showing the shape of an electrostatic electrode forming the electrostatic chuck according to the present invention.

9A to 9D are cross-sectional views schematically showing a manufacturing process of the ceramic heater shown in FIG.

10A is a bottom view schematically showing an example of a conventional ceramic heater, and FIG. 10B is a partially enlarged cross-sectional view thereof.

FIG. 11A is a bottom view schematically showing another example of the conventional ceramic heater, and FIG. 11B is a partially enlarged sectional view thereof.

FIG. 12A is a bottom view schematically showing another example of the conventional ceramic heater, and FIG. 12B is a partially enlarged sectional view thereof.

FIG. 13 is a plan view schematically showing another example of a conventional ceramic heater.

[Explanation of symbols]

10, 30 Ceramic heater 11, 21, 31 Ceramic substrate 11a, 31a Heating surface 11b, 31b bottom 12, 25, 32 resistance heating element 12a, 25a, 32a conductive pad portion 12b, 25b, 32b Metal wiring 121 wire 13, 33 External terminal 14, 34 Bottomed holes 15,35 through holes 16,36 Lifter pin 19, 39 through hole 19a, 39a blind hole 190 Packed bed 20, 40, 60 Electrostatic chuck 29 Semiconductor wafer 50, 50 'green sheet 120 conductive layer

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) H05B 3/10 H05B 3/10 C 3/12 3/12 A 3/20 358 3/20 358 3/74 3/74 F Term (reference) 3K034 AA02 AA04 AA16 AA21 BA06 BB06 HA04 HA10 JA01 JA10 3K092 PP20 QA05 QB02 QB26 QB44 QB62 QB74 QC19 QC20 QC49 RF03 RF11 RF19 RF03 HA02 HA03 HA02 HA30 HA02 HA30 DD01 HA30 HA02 HA30 JA01 PA11

Claims (6)

[Claims] 1. A ceramic heater for a semiconductor manufacturing / inspecting apparatus, comprising a disk-shaped ceramic substrate and a resistance heating element formed of one or a plurality of circuits formed therein, wherein the circuit comprises one or a plurality of metals. A ceramic heater for a semiconductor manufacturing / inspection apparatus, which is formed by connecting wiring through a plurality of conductive pad portions. 2. The ceramic for semiconductor manufacturing / inspection apparatus according to claim 1, wherein the plurality of conductive pad portions are arranged substantially evenly on a circumference of a circle having a concentric relationship with the ceramic substrate. heater. 3. The metal wiring comprises tungsten and / or
Alternatively, the ceramic heater for a semiconductor manufacturing / inspecting apparatus according to claim 1 or 2, which is made of tungsten carbide. 4. A method of manufacturing a ceramic heater for a semiconductor manufacturing / inspecting apparatus, comprising manufacturing a ceramic heater having a resistance heating element inside a ceramic substrate by stacking and firing green sheets, the method comprising: To form a plurality of conductive layers by adhering foil or screen-printing a conductive paste, and connecting one or more conductive wires and / or elongated wires so as to connect the plurality of conductive layers. A conductor arranging step of placing and fixing a foil, a green sheet on which the conductive layer and wires and / or foils are fixed, and a plurality of other green sheets are laminated to produce a green sheet laminate. A semiconductor manufacturing / inspection device including a sheet laminating step and a firing step of degreasing and firing the obtained green sheet laminate. Method for manufacturing stationary ceramic heater. 5. When forming a plurality of conductive layers by adhering a foil or screen-printing a conductor paste on the one green sheet, the circles assumed on the one green sheet are formed. The semiconductor manufacturing according to claim 4, wherein the plurality of conductive layers are arranged substantially evenly on the circumference.
Manufacturing method of ceramic heater for inspection equipment. 6. The semiconductor manufacturing method according to claim 4, wherein the conductive wire and / or the elongated foil is made of tungsten and / or tungsten carbide.
Manufacturing method of ceramic heater for inspection equipment.