JP2003158052A - Ceramic substrate for semiconductor production/ inspection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a ceramic substrate exhibiting excellent temperature rising/ lowering characteristics and chucking capability being used in a production/ inspection system of a semiconductor exhibiting high reliability of connection in which damage of a heating element and breakage of an external terminal itself are prevented even when a force is applied thereto. SOLUTION: In the ceramic substrate embedded with a conductor, a columnar conductive connection pad is provided toward the surface of the substrate starting from the embedded conductor. A bag hole is opened in the connection pad and fixed with an external terminal connection pin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate used for a semiconductor product manufacturing apparatus or inspection apparatus, and more particularly to a hot plate (ceramic heater) or a susceptor used for drying semiconductor products, an electrostatic chuck, or the like. This is a proposal for a ceramic substrate that is useful for a wafer prober and has excellent connection reliability with external terminals.

[0002]

2. Description of the Related Art An integrated circuit or the like provided in a semiconductor product is usually formed by applying a photosensitive resin as an etching resist on a silicon wafer and then etching the resin. In this case, since the photosensitive resin applied to the surface of the silicon wafer is applied by a spin coater or the like, it needs to be dried after application. The drying process is performed by placing a silicon wafer coated with the photosensitive resin on a hot plate and heating it. Conventionally, as the hot plate, that is, the heater used in the semiconductor manufacturing apparatus, there has been used one in which a heating element is wired on the back surface of a substrate made of a metal plate (aluminum plate).

[0003]

However, when a heater made of such a metal substrate is used for drying semiconductor products, there are the following problems. Since the substrate of the heater is made of metal, the thickness of the substrate must be 15 mm or more. This is because a thin metal substrate causes warping or distortion due to thermal expansion due to heating, and the wafer mounted on this substrate is damaged or tilted. Moreover, since the conventional heater is thick, it is heavy and bulky.

Further, when the heating temperature of the heater is controlled by changing the voltage or current amount applied to the heating element mounted on the substrate, if the thickness of the substrate is large, the temperature of the substrate will fluctuate in voltage or current amount. There is also a problem that the temperature control characteristics of the substrate are poor because they do not follow quickly.

In order to solve such a problem, it has hitherto been disclosed in Japanese Patent Laid-Open No.
In Japanese Patent Laid-Open No. 306642 and Japanese Patent Laid-Open No. 4-324276, a ceramic heater using an ALN substrate is proposed. However, JP-A-9-306642
The technique disclosed in Japanese Patent Laid-Open No. 4-324276 is one in which an external terminal connecting pin is directly connected to a rectangular flat plate-shaped metal terminal. Further, in the technique disclosed in Japanese Patent Laid-Open No. 4-324276, a cutout portion is provided to form an external terminal. Each of these technologies has a problem in that when heat is applied to the external terminals, the heating element is easily damaged or the external terminals themselves are damaged.

Therefore, an object of the present invention is not only excellent in temperature raising and lowering characteristics and adsorption ability, but also connection reliability which does not cause a problem of damage to the heating element or damage to the external terminal itself even when force is applied to the external terminal. It is to provide a ceramic substrate used in a semiconductor manufacturing / inspection apparatus having high properties.

[0007]

In order to achieve the above object, a ceramic heater having the following gist structure is effective. That is, according to the present invention, in a ceramic substrate in which a conductor is embedded, a cylindrical conductive connection pad is provided from the embedded conductor as a starting point toward the substrate surface, and the connection pad has a blind hole. And a pin for external terminal connection is attached to the bag hole, which is a ceramic substrate for a semiconductor manufacturing / inspecting apparatus.

The ceramic substrate according to the present invention is
It is preferable that the conductive connection pad and the external terminal connection pin are fixed and electrically connected via the brazing material filled in the bag hole. Further, in the present invention, it is preferable that the conductor is a heating element for a heater or a susceptor, or an electrode for an electrostatic chuck or a wafer prober.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The ceramic substrate according to the present invention serves as a substrate for a susceptor, an electrostatic chuck, a wafer prober in addition to a hot plate, that is, a heater. An example will be explained. In the ceramic heater, a ceramic plate, that is, a portion of a ceramic substrate is made of an insulating nitride ceramic, a carbide ceramic or an oxide ceramic, and the substrate has a flat cross section. A plate-shaped conductor, for example, in the case of a heater, a heating element is embedded inside the ceramic substrate at a position eccentric from the center of thickness in the thickness direction of the substrate, and further away from the heating element. The surface on the side is a work surface, for example, a heating surface in the case of a heater.

A feature of the present invention is that when a heating element embedded in the insulating ceramic substrate and an external terminal connecting pin are electrically connected, the heating element serves as a base point and the non-heating surface side of the substrate A cylindrical conductive connection pad (so-called through-hole post) extending toward the surface is provided, and this connection pad (through-hole post) is hollowed out in the axial direction to form a bag hole. The external terminal connecting pin is fitted into the socket, and the heating element and the external terminal connecting pin are electrically connected through the so-called bag hole.

In the ceramic heater having such a structure, the connection pad is provided in contact with the heating element, and the connection pad itself has a blind hole (a pin stand hole for fitting the external terminal connection pin). The external terminal connecting pin is fitted in the bag hole. Therefore, the pin for terminal connection does not rattle at all, and this pin is directly connected to the columnar (including disc-shaped) conductive connection pad. Even if a force is applied to the external terminal, stress is not concentrated in the bag hole and the connection pad, and the force can be evenly distributed. Therefore, a crack is not generated in the heating element or the substrate, and it also effectively prevents the external terminal from coming off.

In the present invention, the columnar conductive connection pad is used as a conductor for connecting the heating element layers provided over a plurality of layers or a conductor for connecting to an electrostatic chuck. You may use.

An insulating nitride ceramic, carbide ceramic or carbide ceramic is used as a material of the ceramic substrate. This is because these ceramics have a smaller coefficient of thermal expansion than metals, and even if they are thin, they do not warp or distort due to heating. As a result, the present invention allows the substrate itself to be thin and lightweight. Further, since such a ceramic substrate has a high thermal conductivity and the substrate itself is thin, the surface temperature of the ceramic substrate has a characteristic that it easily responds quickly to a temperature change of the heating element. That is, when the voltage and the current amount of the heating element embedded in the ceramic substrate are changed, the changes immediately appear as a temperature change of the substrate heating surface, so that it can be said that the temperature control characteristic and the temperature raising / lowering characteristic are excellent. The substrate preferably has a thickness of about 0.5 to 5 mm. This is because if it is too thin, it will break easily.

As an example of the nitride ceramic, it is desirable to use at least one selected from metal nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, and titanium nitride. As an example of the carbide ceramic, it is desirable to use a metal carbide ceramic, for example, at least one selected from silicon carbide, zirconium carbide, titanium carbide, tantalum carbide, and tungsten carbide. As oxide ceramics, magnesia, alumina, beryllia, zirconia,
It is desirable to use at least one selected from cordierite, mullite and titania. Of these ceramics, aluminum nitride is the most preferred. Thermal conductivity is 18
This is because the highest value is 0 W / mK.

Next, as the heating element, a plate-shaped member having a flat cross section is embedded inside the substrate. Preferably, the embedded position is embedded at a position eccentric from the center of the substrate in the thickness direction. In addition, it is preferable to use a heating surface which is a working surface on the side farther from the heating element.
With this configuration, the heat propagation is likely to be uniformly diffused throughout the ceramic substrate, and the pattern of the heating element is not projected as it is on the heating surface to prevent uneven temperature distribution. The temperature distribution on the surface can be made uniform. That is, it is desirable that the position be over 50% and up to 99% from one surface (heating surface) of the substrate. If it is less than 50%, it is too close to the heating surface and a temperature distribution similar to the pattern of the heating element 2 occurs. On the other hand, if it exceeds 99%, the substrate 1 itself warps and the wafer is damaged. Because.

The flat shape of the heating element is such that the cross-sectional aspect ratio (width of heating element / thickness of heating element) is in the range of 10 to 5000. With such a shape, it is easier to make the temperature distribution on the heating surface more uniform than when the cross section is a perfect circle or the cross section is a shape close to a square. In this respect, when the cross-sectional aspect ratio of the heating element is less than 10, the heat propagation from the heating element in the upward direction (the wafer heating surface direction) is relatively large in the lateral direction (the lateral direction of the ceramic substrate). And the temperature distribution resembles the shape of the heating element. On the other hand, when the aspect ratio exceeds 5000, heat is accumulated in the vicinity of the center of the heating element, and an uneven temperature distribution also occurs, so that it becomes impossible to ensure temperature uniformity.

A more preferable cross-sectional aspect ratio of the heating element is 100 to 3000. That is, the aspect ratio is 100
If it is less than 3, the heating element tends to be a starting point of cracks, while if it exceeds 3,000, the sintering between the green sheets is obstructed to form an interface between the green sheets, which causes cracks. . In the case of a heating element having such an aspect ratio, it is effective even when the impact resistance temperature ΔT of the ceramic substrate (the temperature at which cracks and peeling occur when dropped in water) is 150 ° C. or higher.

Such a heating element 2 is specifically shown in FIG.
As shown in FIG. 2, in order to make the temperature of the entire ceramic substrate 1 uniform, it is preferable to adopt a concentric pattern, the thickness of which is 1 to 50 μm and the width is within the range of the aspect ratio. It is preferable to make a flat plate shape of 5 to 20 mm. Within the above range, it is effective to increase the relative thickness of the heating element for the purpose of preventing disconnection or the like. The reason for limiting the thickness and width in this way is that this range is most practical in controlling the resistance value. Another reason for limiting the structure (thickness, width) of the heating element 2 as described above corresponds to the need to increase the width of the heating element itself. That is, when the heating element 2 is embedded inside the substrate 1, the temperature uniformity of the surface is deteriorated when the distance between the heating surface 1a and the heating element 2 is shortened, and therefore it is effective to widen the heating element.

Since the heating element 2 is embedded in the substrate, it is not necessary to consider the adhesion with the substrate material such as a nitride ceramic, and a refractory metal such as W or Mo or tungsten. It is possible to use carbides such as molybdenum and molybdenum, which in turn can increase the resistance value. The resistance value increases as the heating element 2 becomes thinner and thinner.

The heating element 2 may have a rectangular cross section, an ellipse, a spindle, or a semi-cylindrical shape as long as it is a flat plate. The reason why the flat plate-shaped body is adopted is that when the heating element is provided inside, the flat shape is more likely to dissipate heat toward the heating surface, so that uneven temperature distribution on the heating surface is less likely to occur. The present invention does not include a spiral shape even if the heating element has a flat cross section. This is because it has the same heat transfer effect as a perfect circle.

The heating element 2 may be arranged in a plurality of layers in the thickness direction of the substrate 1. In this case, it is preferable that the patterns of the respective layers are buried in positions complementary to each other when viewed in a plane, so that somewhere on the heating surface must be covered by the pattern of one of the layers. Make it buried. For example, the structures are arranged in a zigzag pattern. In addition, the heating element 2 is the substrate 1
As long as it is embedded in the inside, a part of it may be exposed on the surface.

In the present invention, in order to dispose the heating element at a predetermined position of the ceramic substrate 1, it is formed by a method of applying and printing a conductive paste containing metal particles or the like on a predetermined surface in the thickness direction of the substrate. be able to. The conductive paste generally contains a resin, a solvent, a thickener, etc. in addition to metal particles or conductive ceramics for ensuring conductivity. The metal particles are preferably at least one selected from W and Mo. This is because these metals are relatively hard to oxidize and have a resistance value sufficient to generate heat. As an example of the conductive ceramic, at least one selected from W and Mo carbides can be used. The particle size of these metal particles or conductive ceramics is preferably 0.1 to 100 μm. If it is too fine, it easily oxidizes, and if it is too large, it becomes difficult to sinter,
This is because the resistance value becomes large.

The resin used for the conductive paste is
Epoxy resin and phenol resin are preferable. Further, isopropyl alcohol or the like is used as the solvent.
Examples of the thickener include cellulose and the like.

In the present invention, since the heating element is formed inside the ceramic substrate, the surface of the heating element is not oxidized. Therefore, it is not necessary to coat the surface of the heating element with an antioxidant or the like.

In the present invention, since the heating element 2 is formed inside the ceramic substrate 1, a connection pad (through hole post) for communicating with the outside is required to connect with the pin for connecting an external terminal. The connection pad 4 is formed of a columnar shape extending from the embedded heating element 2 toward the surface of the substrate opposite to the heating surface 1a, and is made of a refractory metal such as W or Mo. It is formed by a paste, a carbide-based conductive ceramic paste such as WC or MoC. The diameter of the connection pad 4 is 0.1 to
The size is preferably 10 mm. That is, if the size of the connection pad 4 is about this size, it is effective in preventing cracks and distortions while preventing disconnection.

The connection pad 4 and the external terminal connection pin 3
For connection with the connection pad 4, a bag hole 5 is opened in the axial direction of the connection pad 4 (direction perpendicular to the plate thickness), a high melting point brazing material is filled in the bag hole 5, and a bag is inserted through this brazing material. This is performed by fixing the external terminal connecting pin 3 inserted in the hole 5.
The brazing material may be gold brazing or silver brazing. Au-Ni alloy is desirable as the gold solder. This is because the Au-Ni alloy has excellent adhesion to tungsten. The Au / Ni alloy ratio in this brazing solder is 81.5-82.5 Au /
18.5 to 17.5Ni is preferable. In addition, this Au-Ni
The thickness of the brazing solder layer is 0.1 to 50μ to secure the connection.
It is desirable to set m. Gold wax like this is 10-6
Even under high vacuum and high temperature of ~ 10-5Pa x 500-1000 ℃
Since it does not deteriorate like Cu alloy, it can be said to be a preferable material.

In the present invention, the thermocouple 6 can be embedded in the ceramic substrate 1 if necessary. This is because the temperature of the ceramic substrate 1 can be measured by the thermocouple 6 and the temperature of the heater plate can be controlled by changing the voltage and current amount based on the data.

In the usage mode of the ceramic heater of the present invention, as shown in FIG. 2, a plurality of through holes 7 are provided in the ceramic substrate 1, and the support pins 8 are inserted into the through holes 7, and the work surface of the substrate is That is, the semiconductor wafer 9 and the like are supported by the tops of the pins 8 protruding toward the heating surface side so as to face the heating surface, and dried by heating. In this usage mode, the support pins 8 are moved up and down to pass the semiconductor wafer 9 to a carrier (not shown), or the semiconductor wafer 9 is transferred from the carrier.
You can also receive.

Next, a method for manufacturing the ceramic heater will be described. (1) A step of mixing a ceramic powder such as a nitride ceramic or a carbide ceramic with a binder and a solvent to obtain a green sheet (green molded body): In the processing of this step, such a ceramic powder is aluminum nitride,
Silicon carbide or the like can be used, and if necessary, a sintering aid such as yttria may be added. As an example of the binder, at least one selected from acrylic binder, ethyl cellulose, butyl cellosolve, and polyvinylal is desirable. As an example of the solvent, at least one selected from α-terpione and glycol is desirable. The paste obtained by mixing these is molded into a sheet by the doctor blade method to produce a green sheet. The obtained green sheet may be provided with a through hole 7 for inserting the support pin 8 for the silicon wafer and a recess 10 for embedding the thermocouple, if necessary. The through holes 7 and the recesses 10 can be formed by applying a punching method or the like. The thickness of the green sheet is preferably about 0.1 to 5 mm.

(2) A step of printing a conductive paste to be a heating element on the green sheet: In the processing of this step, a conductive paste such as a metal paste or a conductive ceramic is applied to the heating element forming portion on the green sheet. , 5 to 40 μm in thickness and 0.5 to 12 μm in width, or applied or printed. These conductive pastes contain metal particles or conductive ceramic particles. Tungsten or molybdenum is the most suitable as such metal particles, and tungsten or molybdenum carbide is most suitable as the conductive ceramic particles. This is because it is difficult to oxidize and the thermal conductivity does not easily decrease.
The average particle diameter of the tungsten particles or molybdenum particles is preferably 0.1 to 5 μm. This is because it is difficult to print the paste when it is too large or too small. Examples of such a paste include metal particles or conductive ceramic particles 85 to 9
1.5 to 10 parts by weight of 7 parts by weight, at least one or more binders selected from acrylic, ethyl cellulose, butyl cellosolve and polyvinylal, 1.5 to 10 parts by weight of at least one solvent selected from α-terpione and glycol. A tungsten paste or a molybdenum paste prepared by partially mixing is most suitable.

(3) At least the conductive paste printed green sheet for the heating element 2 obtained in the step (2) and the green sheet not printed with the paste obtained in the same step as the step (1), respectively. Step of laminating one or more sheets: In this step, when two or more layers of green sheets are laminated, each of the green sheets laminated on the upper side (meaning heating surface side) of the green sheet with paste in (2) It is important that the number of green sheets to be laminated on the lower side is smaller than the number of green sheets (1) so that the embedded position of the heating element 2 is eccentric in the thickness direction. Specifically, 20 to 50 sheets are laminated on the upper side and 5 to 20 sheets are laminated on the lower side.

(4) Step of forming the conductive pad 4 and the bag hole 5 on the green sheet laminated material obtained as described above: This step is performed from the surface of the ceramic substrate 1 on the non-heated side. A cylindrical opening is provided toward the heating element 2, and a W or Mo paste or a WC or MoC paste is filled in the opening to form the connection pad 4, and the connection pad 4 is bored in the axial direction. By doing so, the bag hole 5 reaching the heating element is formed. It should be noted that conductive support members 12 as shown in FIG. 4 may be provided at equal intervals at least at three locations around the outer periphery of the bag hole 5. Then, these conductive support members 12 are exposed on the inner wall surface of the bag hole 5,
It is a preferred embodiment to make the electrical connection with the external terminal connection pin 3 inserted into the connector more reliable.

(5) The green sheet laminate is heated and pressed to sinter the green sheet and various conductive pastes,
Step of obtaining ceramic substrate, heating element, conductive pad and bag hole: In this step, the heating temperature is from 1000 to
Pressurization is performed at 2000 ° C. under an inert gas atmosphere at 100 to 200 kg / cm ² . As the inert gas, argon,
Nitrogen etc. can be used.

(6) Finally, the bag hole 5 provided in the connection pad 4
After printing the Au-Ni alloy paste as a gold solder, the external terminal connecting pin 3 is placed, heated and reflowed. The heating temperature is preferably 200 to 500 ° C. Further, the thermocouple 6 can be embedded if necessary. In the ceramic heater described above, an electrostatic chuck electrode (not shown) described below may be embedded between the wafer heating surface and the heating element.

The hot plate (heater) has been described above as an example of the ceramic substrate for semiconductor manufacturing / inspection equipment. Other embodiments of the present invention include, for example, an electrostatic chuck, a wafer prober, a susceptor, and the like, in addition to the above ceramic heater. For example, semiconductor manufacturing
When an electrostatic electrode is embedded as the electric conductor embedded inside the ceramic substrate that constitutes the inspection device, it functions as the electrostatic chuck 101. The conductive paste used for the electrostatic electrode as the conductor is preferably, for example, one mainly containing a noble metal (Au, Ag, Pt, Pd), or a carbide of W or Mo. Examples of the substrate ceramics include conductive ceramics such as W and Mo carbides. These may be used alone or in combination of two or more.

FIG. 5 is a vertical sectional view schematically showing a ceramic substrate used as an electrostatic chuck. In this ceramic substrate for electrostatic chuck, chuck positive and negative electrode layers 52 and 53 are embedded inside the ceramic substrate 1 and connected to through holes 56 and 57, respectively, and a ceramic dielectric film 54 is formed on the electrodes. There is.

On the other hand, a resistance heating element 55 and a through hole 58 are provided inside the ceramic substrate 1 so that the object semiconductor product 9 to be heated such as a silicon wafer can be heated. An RF electrode may be embedded in the ceramic substrate 1 if necessary. As described above, when the ceramic substrate according to the present invention is used as an electrostatic chuck, the electric conductor, that is, the plate-shaped electrode is arranged so that the adsorption property of a wafer or the like is excellent.

Next, in the ceramic substrate for semiconductor manufacturing / inspection equipment according to the present invention, when a chuck top conductor layer is provided on the surface and a guard electrode or a ground electrode is provided as an internal conductor, What functions as the wafer prober 102 is obtained.

FIG. 6 is a sectional view schematically showing an embodiment of a ceramic substrate configured as a wafer prober. In this wafer prober, concentric grooves 62 are formed on the surface of the ceramic substrate 1 having a circular shape in plan view, and a plurality of suction holes 63 for sucking a silicon wafer are provided in a part of the grooves 62. And the groove 62
A chuck top conductor layer 64 for connecting to an electrode of a silicon wafer is formed in a circular shape on most of the ceramic substrate 1 including.

On the other hand, at a position near the surface on the side opposite to the chuck top conductor layer 64 in the ceramic substrate 1, resistance heating arranged concentrically in plan view is arranged to control the temperature of the silicon wafer. The body 65 is buried. Through holes 66 are provided at both ends of the resistance heating element 65.
The external terminal is connected and fixed via.

In addition, a grid-shaped guard electrode 67 and a ground electrode 68 for removing stray capacitors and noise are provided inside the ceramic substrate 1. In such a wafer prober 102, after mounting a silicon wafer on which an integrated circuit is formed on the ceramic substrate 1, a probe card having tester pins is pressed against this silicon wafer, and a voltage is applied while heating and cooling. A continuity test can be performed.

[0042]

Examples Example 1 (ceramic heater) (1) Aluminum nitride powder (manufactured by Tokuyama, average particle size 1.1)
μm) 100 parts by weight, yttria (yttrium oxide, average particle size 0.4 μm) 4 parts by weight, acrylic binder
A composition prepared by mixing 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 was formed with a doctor blade to obtain a green sheet having a thickness of 0.47 mm. (2) After drying the green sheet at 80 ° C. for 5 hours,
Through holes 7 for inserting semiconductor wafer support pins 8 having a diameter of 1.8 mm, 3.0 mm, 5.0 mm by punching, and for forming connection pads 4 for connecting the heating element 2 and the external terminal connection pins 3 The opening was perforated. (3) Centering on the green sheet on which the tungsten paste forming the heating element 2 is printed, the upper side (heating side)
37 sheets of green sheets on which the conductive paste A for forming the heating element 2 is not printed on the upper side (heating side), and 13 sheets on the lower side opposite to the green sheet, and laminated at 130 ° C and a pressure of 80 kg / cm2. did. Conductive paste A: 100 parts by weight of tungsten carbide particles having an average particle size of 1 μm, acrylic binder 3.0
Parts by weight, 3.5 parts by weight of α-terpione solvent, dispersant 0.
3 parts by weight were mixed to prepare a conductive paste A. Conductive paste B: 100 parts by weight of tungsten particles having an average particle size of 3 μm, 1.9 parts by weight of an acrylic binder, α
A conductive paste B was prepared by mixing 3.7 parts by weight of a terpione solvent and 0.2 part by weight of a dispersant. (4) The green sheet laminate was degreased in nitrogen gas at 600 ° C. for 5 hours and hot pressed at 1890 ° C. and a pressure of 150 kg / cm ² for 3 hours to obtain an aluminum nitride plate-like body having a thickness of 3 mm. This is cut into a circle with a diameter of 230 mm and the thickness is 6
A ceramic plate-shaped body having a heating element of μm and a width of 10 mm was formed (FIG. 3 (a)). (5) After polishing the plate-shaped body obtained in (4) with a diamond grindstone, a mask was placed on the plate-shaped body, and a recess 11 for the thermocouple 6 was provided by blasting with glass beads (FIG. 3 (b)). ). (6) Further, the brazing hole 5 provided in the axial direction of the connection pad 4 is filled with a brazing filler metal made of Ni-Au alloy together with the pin 3 and reflowed by heating at 700 ° C to make a Kovar external terminal connection pin. 3 was connected (Fig. 3 (c)). In addition, this pin 3
The connection is made of tungsten as shown in Fig.4.
It is desirable to have a structure in which 12 supports at 3 points.
This is because connection reliability can be secured. (7) A plurality of thermocouples 6 for temperature control were embedded in the recess 11 to obtain a heater 100 (Fig. 3 (d)).

Example 2 (heater made of silicon carbide ceramic plate) Basically the same as in Example 1, but 100 parts by weight of silicon carbide powder having an average particle size of 1.0 μm, 11.5 parts by weight of an acrylic binder, and 0.5 of a dispersant. A composition obtained by mixing 53 parts by weight of alcohol and 1 part of butanol and ethanol was mixed with a doctor blade to obtain a green sheet having a thickness of 0.50 mm. A ceramic heater was formed by setting the sintering temperature to 1900 ° C.

Comparative Example 1 Basically the same as in Example 1, but the connection pads were prismatic (0.2 mm × 0.2 mm × 0.2 mm). Comparative Example 2 The same as Example 1, except that a cutout portion was provided instead of providing the blind hole. With respect to the heaters of the example and the comparative example, the connection test of the terminal pin and the socket was repeated 500 times to check for damage. The results are shown in Table 1.

[Table 1]

Example 3 (Electrostatic chuck) (1) Aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.
1 μm) 100 parts by weight, yttria (average particle size: 0.4 μ
m) 4 parts by weight, acrylic binder 11.5 parts by weight, dispersant 0.
Using a paste prepared by mixing 5 parts by weight and 53 parts by weight of an alcohol composed of 1-butanol and ethanol, the paste was molded by a doctor blade method to obtain a green sheet having a thickness of 0.47 mm. (2) Next, after drying this green sheet at 80 ° C. for 5 hours, punching it to a diameter of 1.8 mm, 3.0 mm, 5.0 mm.
A portion that will be a through hole for inserting the semiconductor wafer support pin of
A portion to be a through hole for connecting to an external terminal is provided.

(3) 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 a dispersant of 0.
3 parts by weight were mixed to prepare a conductor paste A. 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. This conductor 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, a conductor paste layer having an electrostatic electrode pattern having the shape shown in FIG. 7 was formed on another green sheet.

Further, the conductor paste B was filled in the through holes for through holes for connecting the external terminals. On top of the green sheet that has undergone the above processing, the green sheet on which the tungsten paste is not printed is placed on the upper side (heating side)
34 sheets, and 13 sheets on the lower side, a green sheet on which a conductor paste layer composed of an electrostatic electrode pattern is printed, and two green sheets on which a tungsten paste is not printed are further stacked thereon. And these 130
A laminate was formed by pressure bonding at 80 ° C. and a pressure of 80 kg / cm ² .

(4) Next, the obtained laminated body was placed in a nitrogen gas,
Degreased at 600 ℃ for 5 hours, 1890 ℃, pressure 0-150 kg / cm
² (details in Table 1) were hot pressed for 3 hours to obtain an aluminum nitride plate-like body having a thickness of 3 mm. This is cut into a 230 mm disk shape, and a plate shape made of aluminum nitride having therein a resistance heating element 55 having a thickness of 6 μm and a width of 10 mm, and a chuck positive electrode electrostatic layer 52 and a chuck negative electrode electrostatic layer 53 having a thickness of 10 μm. I made it a body.

(5) Next, after polishing the plate-like body obtained in (4) with a diamond grindstone, a mask is placed and a bottomed hole for a thermocouple is formed on the surface by blasting with SiC or the like. (Diameter: 1.2 mm, depth: 2.0 mm). (6) Furthermore, the portion where the through hole is formed is cut out to form a bag hole, and using Ni-Au gold solder, reflow is performed by heating at 700 ° C and the external terminal 59 made of Kovar is connected. did. Incidentally, the connection of the external terminal 59 is preferably a structure in which a tungsten support body supports at three points as shown in FIG. This is because connection reliability can be secured.

(7) Next, a plurality of thermocouples for temperature control are embedded in a bottomed hole and an electrostatic chuck having a resistance heating element is formed.
101 production completed. With respect to such an electrostatic chuck, the attachment / detachment test of the terminal pin and the socket connected to the power source was carried out 500 times, but there was no crack, peeling of the terminal pin, breakage of the heating element, or electrostatic electrode. Electrostatic chucks are often cleaned with corrosive gases and require maintenance. Therefore, the present invention in which cracks and the like do not occur even when the electrostatic chuck is attached or detached is most suitable as the electrode structure of the electrostatic chuck.

Example 4 (Wafer prober) (1) Aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.
1 μm) 100 parts by weight, yttria (average particle size 0.4 μm)
A mixed composition obtained by mixing 4 parts by weight, 0.9 parts by weight of the amorphous carbon obtained in Example 1, and 53 parts by weight of alcohol consisting of 1-butanol and ethanol was molded using a doctor blade method. Then, a green sheet having a thickness of 0.47 mm was obtained. (2) Next, this green sheet was dried at 80 ° C. for 5 hours and then punched to form through holes for through holes for connecting the heating element and external terminals.

(3) 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 a dispersant of 0.
3 parts by weight were mixed to prepare a conductive paste A. In addition, 100 parts by weight of tungsten particles having an average particle diameter of 3 μm, 1.9 parts by weight of an acrylic binder, and α-terpineol solvent were added to 3.
7 parts by weight and 0.2 parts by weight of the dispersant were mixed to prepare a conductive paste B. Next, a grid-shaped guard electrode print body and a ground electrode print body were printed on the green sheet by screen printing using the conductive paste A. Further, the conductive paste B was filled into the through holes for through holes for connecting to the external terminals. Further, 50 printed green sheets and 50 unprinted green sheets were laminated and integrated at 130 ° C. and a pressure of 80 kg / cm ² to prepare a laminate.

(4) Next, this laminated body was subjected to 600 g in nitrogen gas.
Degreasing was performed at 5 ° C. for 5 hours, and hot pressing was performed at 1890 ° C. and a pressure of 150 kg / cm ² for 3 hours to obtain an aluminum nitride plate-shaped body having a thickness of 3 mm. The obtained plate-shaped body was cut into a circular shape having a diameter of 300 mm to obtain a ceramic plate-shaped body. The size of the through hole 16 was 0.2 mm in diameter and 0.2 mm in depth. Further, the thickness of the guard electrode 67 and the ground electrode 68 is 10 μm, the formation position of the guard electrode 67 is 1 mm from the wafer mounting surface, and the formation position of the ground electrode 68 is 1.2 mm from the wafer mounting surface.
Met. In addition, the guard electrode 67 and the ground electrode 6
The size of one side of the conductor non-formed area of No. 8 was 0.5 mm.

(5) After polishing the plate-like body obtained in (4) above with a diamond grindstone, a mask is placed and a blast treatment with SiC or the like is performed on the surface to form a concave portion for a thermocouple and a wafer adsorption portion. A groove 62 (width 0.5 mm, depth 0.5 mm) was provided.

(6) Further, a layer for forming the heating element 65 was printed on the surface facing the wafer mounting surface. The printing used conductive paste. The conductive paste used was Solbest PS603D manufactured by Tokuriki Kagaku Kenkyusho, which is used for forming through holes in printed wiring boards. This conductive paste is a silver / lead paste, and contains 100 parts of silver by weight of a metal oxide composed of lead oxide, zinc oxide, silica, boron oxide, and alumina (each weight ratio is 5/55/10/25/5). It contained 7.5 parts by weight per part. Further, the silver had a flaky shape with an average particle size of 4.5 μm.

(7) After the conductive paste was printed, it was heated and baked at 780 ° C. to sinter silver and lead in the conductive paste and to burn it on the ceramic substrate 1. Furthermore, nickel sulfate 30g / l, boric acid 30g / l, ammonium chloride 30g
Nickel layer having a thickness of 1 μm and a boron content of 1% by weight or less on the surface of the silver sintered body by immersing the substrate in an electroless nickel plating bath consisting of an aqueous solution containing 1 / l of Rochelle salt and 60 g / l of Rochelle salt. (Not shown) was deposited. Then, the substrate was annealed at 120 ° C. for 3 hours. The heating element made of a silver sintered body had a thickness of 5 μm, a width of 2.4 mm, and an area resistivity of 7.7 mΩ / □.

(8) A titanium layer, a molybdenum layer, and a nickel layer were sequentially formed on the surface where the groove 62 was formed by a sputtering method. As an apparatus for sputtering, SV-4540 manufactured by Nippon Vacuum Technology Co., Ltd. was used. Sputtering conditions are atmospheric pressure 0.6 Pa, temperature 100 ° C., electric power 20.
0 W and the sputtering time was adjusted for each metal within the range of 30 seconds to 1 minute. The thickness of the obtained film was 0.3 μm for the titanium layer from the image of the fluorescent X-ray analyzer,
The molybdenum layer was 2 μm, and the nickel layer was 1 μm.

(9) Nickel sulfate 30 g / l, boric acid 30 g /
1, ammonium chloride 30g / l and Rochelle salt 60g
In an electroless nickel plating bath consisting of an aqueous solution containing
The ceramic substrate obtained in (8) above is dipped to deposit a nickel layer having a thickness of 7 μm and a boron content of 1% by weight or less on the surface of the metal layer formed by sputtering.
Annealed at 120 ° C. for 3 hours. The heating element surface does not carry an electric current and is not coated with electrolytic nickel plating.

Further, 2 g of potassium gold cyanide on the surface /
1, ammonium chloride 75g / l, sodium citrate 50
The electroless gold plating solution containing g / l and 10 g / l of sodium hypophosphite was immersed for 1 minute at 93 ° C. to form a gold plating layer having a thickness of 1 μm on the nickel plating layer.

(10) An air suction hole 63 is formed through a drilling process so as to escape from the groove 62 to the back surface.
A bag hole (not shown) for exposing 6 was provided. Ni-Au alloy (Au: 81.5 wt%, Ni: 18.4 wt%,
Impurity: 0.1% by weight) was used to heat and reflow at 970 ° C. to connect an external terminal made of Kovar.
In addition, external terminals made of Kovar were formed on the heating element via solder (90% by weight of tin / 10% by weight of lead).

(11) Next, a plurality of thermocouples for temperature control were embedded in the recess to obtain a wafer prober 102. With respect to such a wafer prober, the attachment / detachment test of the terminal pin and the socket for connecting to the power source was conducted 500 times, but there was no crack, peeling of the terminal pin, breakage of the heating element, guard electrode, and ground electrode.

[0062]

As described above, according to the ceramic substrate for semiconductor manufacturing / inspection equipment of the present invention, the temperature raising / lowering characteristics (heater, susceptor) and the adsorption capacity (electrostatic chuck,
Wafer prober) is excellent, and even if force is applied to the external terminals, there is no damage to the heating element or damage to the external terminal connection pin itself, and there is also a plate-shaped conductor such as a heating element or electrode embedded inside. And the connection reliability with external terminals is excellent.

[Brief description of drawings]

FIG. 1 is a schematic view showing a pattern of a heating element.

FIG. 2 is a cross-sectional view showing a usage state of a ceramic heater.

FIG. 3 is a schematic diagram showing a manufacturing process of a ceramic heater.

FIG. 4 is a schematic view showing how an external terminal connecting pin is supported by a conductive supporting member.

FIG. 5 is a vertical sectional view of an electrostatic chuck.

FIG. 6 is a vertical cross-sectional view of a wafer prober.

FIG. 7 is a schematic diagram of an internal electrode pattern.

[Explanation of symbols]

1 Ceramic substrate 2 heating element 3 External terminal connection pin 4 connection pads 5 bag holes 6 thermocouple 7 through holes 8 Wafer support pins 9 wafers 11 recess 12 Conductive support member 100 ceramic heater 101 electrostatic chuck 102 wafer prober

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 3/20 393 H05B 3/74 3/74 H01L 21/30 567 (72) Inventor Yasuji Hiramatsu Gifu Prefecture Ibi 1-1 Kitakata, Ibiden Co., Ltd., Ibiden-gun, F-Term (Reference) 3K034 AA02 AA04 BB06 BB14 BC04 BC16 BC29 CA02 CA26 CA32 DA04 HA01 HA10 JA01 3K092 PP20 QA05 QB02 QB18 QB20 QC QC43 QC52 QC58 QC62 RF03 RF11 RF17 RF26 RF27 VV31 4M106 AA01 BA01 DD30 5F031 CA02 HA02 HA13 HA17 HA19 HA33 HA37 JA01 JA46 MA33 5F046 KA04 KA10

Claims (3)

[Claims] 1. A ceramic substrate in which a conductor is embedded, a cylindrical conductive connection pad is provided from the embedded conductor toward the surface of the substrate, and the connection pad has a blind hole. A ceramic substrate for a semiconductor manufacturing / inspecting device, which is opened, and external terminal connecting pins are attached to the bag hole. 2. The ceramic according to claim 1, wherein the conductive connection pad and the external terminal connection pin are fixed and electrically connected via a brazing material filled in the bag hole. substrate. 3. The ceramic substrate according to claim 1, wherein the conductor is a heater, a susceptor heating element, an electrostatic chuck electrode, and a wafer prober electrode.