JP3222121B2 - Ceramic heater for semiconductor manufacturing and inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic heater for a semiconductor manufacturing / inspection apparatus mainly used in the semiconductor industry, and more particularly to a ceramic heater having a heating element pattern in which a singular point whose temperature is reduced does not occur. The present invention relates to a ceramic heater for drying.

[0002]

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

In order to form these various circuits, a conductive thin film is formed on a silicon wafer, and then an etching resist made of a photosensitive resin or the like is applied through a mask having a circuit pattern, and pattern etching is performed. I do. When applying this etching resist, since the photosensitive resin is a viscous liquid, it is necessary to dry after the application, and it is usual to place the silicon wafer coated with the photosensitive resin on a heater and heat and dry it. Is being done. In addition, it was necessary to heat the wafer during plasma etching, sputtering, and the like.

A heater of this type for mounting and drying a semiconductor wafer such as a silicon wafer on a heater by heating is conventionally provided with a heating element such as an electric resistor on the back side of an aluminum substrate. Although the thing was used a lot, since the substrate made of aluminum requires about 15 mm in thickness,
Not only is it difficult to handle because the weight is large and bulky, but also because the heating is performed by an electric resistor, the temperature controllability in terms of the temperature followability to the flowing current is insufficient, and uniform heating is obtained. It was not easy. Therefore, as disclosed in JP-A-11-40330,
There has been proposed a ceramic heater provided with a linear heating element formed by sintering metal particles or the like on the surface of a plate made of nitride ceramic or the like.

[0005]

However, when a heating element is formed on such a ceramic heater, if the heating element is formed in a pattern having a bent portion, the temperature of the bent portion decreases, and the surface temperature becomes uneven. However, there was still room for improvement. Such uneven surface temperature was more remarkable in ceramics having higher thermal conductivity such as nitride ceramics.

The present invention uses a ceramic material having a high thermal conductivity as a heater substrate to provide a semiconductor having excellent temperature uniformity.
An object of the present invention is to provide a ceramic heater for a body manufacturing / inspection apparatus .

[0007]

According to a first aspect of the present invention, there is provided a ceramic heater for a semiconductor manufacturing / inspection apparatus , wherein a heating element is provided on a surface of a disk-shaped ceramic substrate.
A pattern is formed, and the heating element pattern forming surface
Semiconductor wafer heating on the wafer heating surface opposite to
A ceramic heater for a body manufacturing / inspection apparatus, wherein
The diameter of the lamic substrate is 200 mm or more,
Mick is a nitride ceramic, carbide ceramic alone
Or two or more types, and bend to the outer edge.
A curved pattern is arranged, and the curved pattern has a curvature.
Bending to bend with a radius of 0.1 to 20 mm
It is intended to have a part .

[0008] With this configuration, there is no temperature drop at the bent portion of the heating element arrangement pattern (sometimes called a heating element pattern). If the bent portion does not draw a radius, for example, if it bends at a right angle, the temperature of the right angle portion will drop. In the following description, the heating element pattern is represented by a shape in a top view, but the position in the thickness direction of the ceramic substrate on which the heating element is disposed may not be on the same plane.
It may include a portion that is vertically positioned in the thickness direction.

The present inventors have conducted intensive studies on the causes of the problems according to the prior art, and as a result, have found the following causes. FIG. 5 shows a heating element 32 used in a conventional ceramic heater. As shown in FIG. 5, a part of the heating element is bent at a right angle. Then, the temperature of the right-angle bent portion (arrow 32a) is lower than the temperatures of the other portions. The reason for this is that the pattern widths h1 and h3 of the substantially straight portion and the pattern width h2 of the right-angled bent portion are different. In the case shown in FIG.
Since the pattern width h2 is larger than the pattern widths h1 and h3, the resistance value of the portion of the pattern width h2 decreases, but this causes a singular point (spot) whose temperature has decreased in the corresponding portion. .

Particularly, in the case of a disk-shaped ceramic heater, uniformity of temperature distribution is required, unlike a square-shaped ceramic heater. In the case of a square ceramic heater, since the propagation of heat is concentric, the surface temperature at the four corners is reduced, so that uniformity of the temperature distribution is not originally required. This is apparent from FIGS. FIG. 7 shows a square ceramic heater.
FIG. 3 is a diagram in which the temperature is raised to 400 ° C. and the surface of a heated surface of a heated object such as a wafer is observed with a thermoviewer. As a result, the temperature of the four corners is low, and it can be understood that the rectangular ceramic heater has characteristics that are not originally required, such as the uniformity of the temperature distribution. However, in the case of a disk shape, the temperature distribution can be made uniform, so that uniformity of the temperature distribution is required, and the semiconductor wafer can be mounted because of the uniformity. For this reason, in such a disk shape, it is necessary to prevent the occurrence of a singular point (spot) whose temperature has decreased.

Therefore, the inventors of the present invention set k1 = k2 = k3 by providing a heating element with a bent portion which bends in a round shape as shown in FIG. The inventors have found that the present invention can prevent the reduction of the resistance value and the occurrence of a singular point (spot) having a lowered temperature, thereby completing the present invention.

According to the ceramic heater for a semiconductor manufacturing / inspection apparatus having the above-described configuration, since the bent portion of the heating element pattern is bent in a round shape, the width of the pattern becomes substantially constant. No local temperature drop occurs. Therefore, the temperature of the ceramic heater is made uniform. Incidentally, Japanese Patent Application Laid-Open No. 9-289075, Utility Model Publication No. 3-19292, Utility Model Publication No. 54-12
Japanese Patent No. 8945 discloses a rectangular ceramic heater in which a bent portion is formed in a bent pattern portion, but this is a square heater and not a disk shape as in the present invention. As a result, the temperatures at the four corners decrease, and temperature uniformity cannot be achieved at all. Also, Japanese Patent Application Laid-Open No. 9-827
No. 86 discloses a heater in which a space is formed between a bulk of a heating element and a ceramic substrate, but this does not integrate the ceramic substrate and the heating element as in the present invention. For this reason, since heat is not transmitted in the space, the temperature of the heating surface cannot be made uniform as in the present invention. JP-A-53-6936 discloses an electric heating appliance in which a heating element is arranged on one side of a ceramic heating plate. However, this is used for microwave ovens and electric stoves.In consideration of the effects on the human body and the reactivity of ceramics, water-resistant and non-toxic ceramics such as alumina and silica, that is, oxide ceramics, are used. Therefore, a nitride or carbide ceramic as in the present invention cannot be used. Such an oxide ceramic has poor temperature followability (the temperature does not immediately rise even when the temperature rises). In these documents, the radius of curvature of bending is not described or suggested, and it is added that these documents do not hinder the patentability of the present invention.
Incidentally, the ceramic heater according to the present invention can be used at 150 ° C. to 800 ° C. according to the application. In the present invention, the term “bend” refers to a case where the pattern is substantially parallel before and after the bent portion of the heating element pattern as shown in FIG. 1B, or as shown in FIG. 3 before and after the bent portion of the heating element pattern. When the pattern forms a right angle, an acute angle, or an obtuse angle, the configuration of the present invention is particularly advantageous because the case where the pattern has an angle before and after the bent portion as in the latter is more likely to cause a temperature drop. .

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1A is a plan view showing a main part of a ceramic heater 100 according to an embodiment of the present invention, and FIG. 1B is an enlarged view of a dotted line part in FIG. Things. FIG. 2 is an enlarged view of a heating element pattern provided on the ceramic heater 100, and FIG. 3 is an enlarged view of a part of the heating element pattern. FIG. 4 shows the ceramic heater 10.
FIG. 2 is a partial cross-sectional view showing the structure of No. 0.

In these figures, the ceramic heater 1
Reference numeral 00 denotes a plate-shaped ceramic substrate 1 made of an insulating nitride ceramic or carbide ceramic, and a heating element pattern 2 having a specific width on one main surface of the ceramic substrate 1 and having a flat cross section. It is formed as shown in FIG. 1, and a silicon wafer or the like is placed on another main surface and heated.

The form of the heating element pattern is formed by a linear shape or a substantially straight or curved line having a width. The shape of the cross section of the heating element is not limited as long as it is flat, and may be square, elliptical, or the like. Further, the linear heating element may have a spiral shape. It is desirable that the aspect ratio (width of the heating element / thickness of the heating element) of the cross section of the heating element pattern 2 is 10 to 5000. By adjusting to this range,
This is because the resistance value of the heating element pattern 2 can be increased, and the uniformity of the temperature of the heating surface can be ensured.

Incidentally, when the thickness of the heating element pattern 2 is constant, if the aspect ratio is smaller than the above range, the amount of heat transmission in the wafer heating direction of the ceramic substrate 1 becomes small, and the heating element pattern 2 Approximate heat distribution occurs on the heating surface. Conversely, if the aspect ratio is too large, the temperature immediately above the center of the heating element pattern 2 will be high, and eventually a heat distribution similar to the heating element pattern 2 will be generated on the heating surface. Therefore, in consideration of the temperature distribution, the aspect ratio of the cross section is preferably 10 to 5000.

When the heating element pattern 2 is formed on the surface of the ceramic substrate 1, the thickness of the heating element pattern 2 is set to 1
-30 μm is preferable, and 1-10 μm is more preferable.
When the heating element pattern 2 is formed inside the ceramic substrate 1, the thickness is preferably 1 to 50 μm. A heating element pattern 2 is provided on the surface of the ceramic substrate 1.
Is formed, the width of the heating element pattern 2 is 0.1
-20 mm is preferable, and 0.1-5 mm is more preferable. Further, a heating element pattern 2 is provided inside the ceramic substrate 1.
Is formed, the width of the heating element pattern 2 is 5
~ 20 µm is preferred.

The heating element pattern 2 shown in FIG. 1 is a hybrid of a spiral pattern and a bent pattern, but it is desirable to dispose the bent pattern at an edge near the outer periphery. This is because the bent pattern can increase the wiring density, so that the temperature can be suppressed from decreasing near the outer peripheral edge, where the temperature tends to decrease. Further, the heating element pattern 2 may be composed of only a bending pattern as shown in FIG.

Heating element pattern 2 shown in FIGS. 1 and 2
FIG. 3 shows an example of the bent portion, which has a predetermined width as shown in FIG. Therefore, the pattern width k1, k2, and k3 of the heating element pattern 2 is k1 = k2.
= K3, and the bent portion has a radius of curvature r. For this reason, the heating element pattern 2 has a configuration in which a reduction in resistance due to a difference in pattern width and a generation of a singular point (spot) whose temperature is reduced due to the reduction are prevented.

Here, the material of the ceramic substrate is preferably an aluminum nitride sintered body, but is not limited thereto. In addition, carbide ceramics, oxide ceramics, and nitrides other than aluminum nitride may be used. Ceramics and the like are preferred.

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

Of these ceramic materials, nitride ceramics and carbide ceramics are generally preferable to oxide ceramics in that they exhibit high thermal conductivity. These materials may be used alone or in combination of two or more. For example, an oxide ceramic or a carbide ceramic may be added to the nitride ceramic, or an oxide ceramic or a carbide ceramic may be added to the carbide ceramic. The higher the thermal conductivity of the ceramic, the more the temperature of the bent portion drops significantly, and the greater the effect of the present invention. The thickness of the ceramic substrate of the present invention is desirably 50 mm or less, particularly preferably 18 mm or less. In particular, when the thickness of the ceramic substrate exceeds 18 mm, the heat capacity of the ceramic substrate increases, and particularly when heating and cooling with the provision of a temperature control means, the temperature followability is reduced due to the large heat capacity. is there. Also,
The problem of non-uniform temperature solved by the ceramic substrate of the present invention is because it does not easily occur with a ceramic substrate having a thickness exceeding 18 mm. Particularly, 5 mm or less is optimal. The thickness is desirably 1 mm or more. The diameter of the ceramic substrate of the present invention is desirably 200 mm or more.
In particular, it is desirable to be 12 inches (300 mm) or more. This is because it will become the mainstream of next-generation silicon wafers.
Further, the problem of non-uniform temperature solved by the present invention is that the diameter is 2 mm.
This is because it hardly occurs on a ceramic substrate of 00 mm or less. In the ceramic substrate of the present invention, the ceramic substrate desirably contains 5 to 5000 ppm of carbon. By containing carbon, the ceramic substrate can be blackened, and radiant heat can be sufficiently utilized when used as a ceramic heater. The carbon may be amorphous or crystalline. When amorphous carbon is used, a decrease in volume resistivity at high temperatures can be prevented, and when crystalline one is used,
This is because a decrease in thermal conductivity at a high temperature can be prevented. Therefore, depending on the application, both crystalline carbon and amorphous carbon may be used in combination. Further, the content of carbon is more preferably 50 to 2000 ppm. When carbon is contained in the ceramic substrate,
The brightness is N based on the value of JIS Z 8721.
It is desirable that carbon be contained so as to be 4 or less. This is because a material having such a lightness is excellent in radiant heat and concealing property. Here, the lightness N is 0 for an ideal black lightness, 10 for an ideal white lightness, and a perception of the brightness of the color between these black lightness and white lightness. Each color is divided into 10 so as to have a uniform rate, and is displayed with symbols N0 to N10. The actual measurement of lightness is N0
The comparison is made with the color chart corresponding to .about.N10. In this case, the first decimal place is 0 or 5. In the ceramic substrate of the present invention, in addition to placing the silicon wafer in contact with the wafer mounting surface of the ceramic substrate, the silicon wafer is supported by support pins or the like, and the silicon wafer is connected to the ceramic substrate as shown in FIG. In some cases, a certain interval is maintained. In FIG. 4, the support pins 7 are inserted through the through holes 8 to hold the silicon wafer 9. By moving the support pins 7 up and down, the silicon wafer 9 can be received from the carrier, the silicon wafer 9 can be placed on a ceramic substrate, or the silicon wafer 9 can be heated while being supported on pins (not shown). A heating element 2 is formed on the bottom surface of the ceramic substrate, and a metal coating layer is provided on the surface of the heating element 2. A bottomed hole is provided, into which a thermocouple is inserted. In this mode, the heating element is formed on the surface of the ceramic substrate, and can adjust the resistance value or blow a cooling gas at the time of cooling, thereby enabling rapid cooling. Further, since the entire region in the thickness direction of the ceramic substrate can be used as a heat diffusion plate, the ceramic substrate can be made thinner and the heat capacity can be made smaller than in the case where a heating element is provided inside, so that rapid temperature rise and fall are possible. The silicon wafer 9 is heated on the wafer heating surface side opposite to the heating element formation surface. Next, a method for manufacturing the ceramic heater 100 according to the present invention will be described. In the following description, the process conditions are merely examples, and are not limited to this embodiment. Therefore, the process conditions are set with appropriate changes depending on the size of the sample, the throughput, and the like.

First, 100 parts by weight of aluminum nitride powder (average particle size: 1.1 μm) and yttria (average particle size: 0.1 μm) were used.
4 μm) 4 parts by weight, 12 parts by weight of an acrylic resin binder, and alcohol were mixed and kneaded, and then granulated by a spray dryer method. Also, when silicon carbide is used, silicon carbide powder (average particle size 1.0 μm) 1
After mixing and kneading 00 parts by weight, 0.5 parts by weight of C or B ₄ C, 12 parts by weight of an acrylic resin binder, and alcohol, a granular powder was obtained by a spray dryer method. Alumina is used in a test example and the like described later. In this case, alumina powder (average particle size: 1.0 μm)
And 12 parts by weight of an acrylic resin binder and alcohol were mixed and kneaded, and then a granular powder was formed by a spray dryer method.

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

The formed body having the through-holes and the recesses formed therein was hot-pressed at about 1800 ° C. and a pressure of 200 kg / ccm ² to obtain a 3 mm-thick aluminum nitride or silicon carbide plate-like sintered body. This was cut out into a disk shape having a diameter of 210 mm to obtain a ceramic substrate 1 for the ceramic heater 100. After forming an insulating film such as an oxide film on the surface of the ceramic substrate, it is desirable to print a heating element described later. Specifically, a glass paste is applied and 1000 ° C.
As described above, there are a method of heating and melting and a method of baking the surface of the ceramic substrate at 500 to 1000 ° C. in an oxidizing atmosphere. In particular, in the case of carbide ceramics, if the purity is low, there is electrical conductivity, so it is desirable to form an insulating film. The thickness of the insulating film is preferably 0.1 to 1000 μm.

A conductive paste was printed on the ceramic substrate 1 by screen printing so that the heating element patterns 2 were arranged in the pattern shown in FIG. The conductive paste used here was Solvest PS6 manufactured by Tokuriki Chemical Laboratory.
03D (trade name), and the conductive paste is a metal oxide composed of a mixture of lead oxide, zinc oxide, silica, boron oxide, and alumina (the weight ratio is 5/5 in this order).
5/10/25/10) 7.5% by weight based on the amount of silver
It is a so-called lead-containing silver paste. Incidentally, the average particle size of silver was 4.5 μm, and the shape was mainly flake-like.

The ceramic substrate on which the conductive paste was printed was heated and fired at 780 ° C. to sinter silver and lead in the conductive paste, and baked on the ceramic substrate. At this time, the heating element pattern made of the lead-containing silver sintered body had a thickness of about 5 μm, a width of 2.4 mm, and a sheet resistance of 7.7 mΩ / □. The heating element pattern has a pattern that bends while drawing a radius at an edge portion near the outer periphery. The radius of curvature of the radius is desirably 0.1 mm to 20 mm. If it is too small, it becomes a right angle, and if it is too large, the heating element pattern density cannot be increased. The radius of curvature is defined by the center line (L in FIG. 3) of the heating element pattern.

Next, the concentration per liter was 80 g / l of nickel sulfate and 24 g of sodium hypophosphite.
g / l, sodium acetate 12 g / l, boric acid 8 g / l,
The ceramic substrate is immersed in an electroless nickel plating bath containing an aqueous solution having a concentration of ammonium chloride of 6 g / l to deposit a nickel metal layer having a thickness of about 1 μm on the surface of the lead-containing silver sintered body. Thus, a heating element pattern was formed.

As shown in FIG. 1 (a), the heating element patterns 2, 31, 31a are formed on the ceramic substrate 1 in a predetermined pattern as shown in FIG. Metal particles and metal oxide particles can be sintered to such an extent that they are fused together. And
The form of the heating element pattern is as shown in FIG.
What is necessary is just a width | variety substantially straight line or curve. Therefore, it does not need to be a strictly geometrically straight line or curve.

Finally, as shown in FIG. 4, a silver-containing lead solder paste (Tanaka Kikinzoku Kogyo Co., Ltd.) is applied by screen printing to a portion where terminal pins 3 for securing the connection between the heating element pattern 2 and the power supply are to be attached. )) Printed on the solder layer 6
The terminal pins 3 made of Kovar were placed on the solder layer and heated and reflowed at 420 ° C. to attach the terminal pins 3 to the surface of the heating element pattern 2.

Further, a thermocouple (not shown) for controlling the temperature was embedded in the ceramic substrate 1 to obtain a ceramic heater 100 according to the present invention. 4, reference numeral 7 denotes a support pin for supporting the semiconductor wafer 9;
Is inserted through the through-hole 8 formed in the ceramic substrate 1. Since the heating element pattern 2 has a predetermined resistance value, the heating element pattern 2 is energized from a position where a terminal pin 3 for energizing the heating element pattern 2 is attached. Generates heat by Joule heat and heats the semiconductor wafer 9.

Next, a method of manufacturing a ceramic heater (FIG. 9) having a heating element formed therein will be described.

(1) First, a ceramic powder of a nitride ceramic or a carbide ceramic is mixed with a binder and a solvent to obtain a green sheet. As the above-mentioned ceramic powder, for example, aluminum nitride or the like can be used, and a sintering aid such as yttria may be added as necessary. The sintering aid can be adjusted at 0.1 to 10% by weight. The average particle size of the ceramic powder is
0.1 to 10 μm. The binder is preferably at least one selected from an acrylic binder, ethyl cellulose, butyl cellosolve, and polyvinyl alcohol. Further, as the solvent, at least one selected from α-terpineol and glycol is desirable. A paste obtained by mixing these is shaped into a sheet by a doctor blade method to produce a green sheet. Note that alumina powder can be produced under the same conditions.
The green sheet may be provided with a through hole for inserting a support pin of the silicon wafer and a concave portion for burying a thermocouple as needed. The through holes and the concave portions can be formed by panning or the like. The thickness of the green sheet is 0.1
About 5 mm is preferable. Next, a conductor paste to be a resistance heating element is printed on the green sheet. Printing is performed such that a desired aspect ratio is obtained in consideration of the shrinkage ratio of the green sheet. As the conductive ceramic particles contained in these conductive pastes, tungsten or molybdenum carbide is most suitable. This is because it is hard to be oxidized and the thermal conductivity is hard to decrease. Further, as the metal particles, for example, tungsten, molybdenum, platinum, nickel and the like can be used. The average particle diameter of the conductive ceramic particles and the metal particles is preferably 0.1 to 5 μm. This is because it is difficult to print the conductor paste when these particles are too large or too small. As such a paste, metal particles or conductive ceramic particles 85 may be used.
To 97 parts by weight, 1.5 to 10 parts by weight of at least one kind of binder selected from acrylic, ethyl cellulose, butyl cellosolve and polyvinyl alcohol, and at least one kind of solvent selected from α-terpineol, glycol, ethyl alcohol and butanol. 0.5-1
The paste for conductor prepared by mixing 0 parts by weight is most suitable. Further, a conductor paste is filled into the holes formed by punching or the like to obtain a through-hole print. Next, a green sheet having a printed body and a green sheet having no printed body are laminated. The reason why the green sheet having no printed body is laminated on the side where the resistance heating element is formed is to prevent the end face of the through hole from being exposed and being oxidized during firing for forming the resistance heating element. If baking for forming the resistance heating element is performed while the end face of the through hole is exposed, it is necessary to sputter a hardly oxidizable metal such as nickel, and more preferably, to coat with Au-Ni gold solder. Is also good.

(2) Next, the laminated body is heated and pressed to sinter the green sheet and the conductive paste integrally. Heating temperature is 1000-2000 ° C, pressurization is 1
Preferably 00~200kg / cm ^2, these heat and pressure are carried out in an inert gas atmosphere. As the inert gas, argon, nitrogen, or the like can be used.

(3) Next, a blind hole for connecting an external terminal is provided. At least a part of the inner wall of the blind hole is preferably made conductive, and the conductive inner wall is preferably connected to the resistance heating element 5 or the like (FIG. 9B).

(4) Finally, an external terminal is provided in the blind hole via a brazing filler metal. Furthermore, if necessary, a bottomed hole is provided,
A thermocouple can be embedded therein. Solder is silver-
Alloys such as lead, lead-tin and bismuth-tin can be used. Note that the thickness of the solder layer is 0.1 to 50 μm.
Is desirable. This is because the range is sufficient to secure the connection by soldering. With such a method, the ceramic heater 200 shown in FIG. 9A can be manufactured. In the ceramic heater 200, the resistance heating element 20 is formed integrally with the ceramic substrate 10 inside the ceramic substrate 10, and the periphery of the resistance heating element 20 is completely in contact with the ceramic substrate 10. Therefore, heat is transmitted uniformly. The wafer 9 is directly placed on the heating surface 10a side of the ceramic substrate 10 or is separated by a predetermined distance (5 to 50) via the separation support pin SP.
00 [mu] m) spaced apart and heated. Heating element 20
Is exposed from the ceramic substrate by the opening. The heating element 20 is connected to a through hole S. The through hole S is connected to the inner wall 40 of the hole that has been made conductive, and the inner wall 40 is connected to the pin 30 via the gold solder 50. Support pins (lifter pins) 80 on the ceramic substrate
Is formed.

(Evaluation Test) As the product of the present invention, four types of aluminum nitride and silicon carbide ceramics each having a heating element pattern formed on the surface, each having a different curvature of the bending pattern were manufactured, and each of them was manufactured. Examples 1 to 8 were used. Four types of aluminum nitride ceramics and silicon carbide ceramics, each having a heating element pattern formed therein and having different curvatures of the bending pattern, were manufactured, and these were named Examples 9 to 16, respectively. As comparative products, ceramic heaters having a heating element pattern having a substantially right-angled bent pattern as shown in FIG. 6 on the surface and inside were manufactured using aluminum nitride and silicon carbide, respectively, to thereby obtain Comparative Examples 1 to 4. Also,
As another comparative example, patterns having a radius of curvature of 25 mm were formed on the surface and inside with a ceramic heater of aluminum nitride and silicon carbide, and these were used as Test Examples 1 to 4. Further, ceramic heaters using an alumina substrate having a heating element pattern formed on the surface and inside were manufactured, and Test Examples 5 to 16 were produced. Furthermore, square ceramic heaters were manufactured from aluminum nitride ceramic and silicon carbide ceramic (both having a pattern formed on the surface). Comparative Examples 5 and 6 were used, and the temperature was raised to 300 ° C. to measure the temperature difference between the four corners and the center. did. At the time of the evaluation test, a voltage was applied to each of the examples and comparative examples, and the samples were heated to 300 ° C.
The temperature near the bent portion of the bent pattern and the temperature near the spiral pattern were measured with an SC-1602 (1980) K-type thermocouple, and the difference was examined. Further, the temperature rise time up to 300 ° C. was measured. Table 1 shows the results. Further, the temperature of the ceramic heater was raised to 200 ° C., and the temperature was dropped into water to examine whether or not cracks developed in the bent portion.

[0038]

[Table 1]

As is apparent from the results, according to the ceramic heater according to the present invention, the difference between the temperature near the bent pattern for drawing the radius and the temperature near the spiral pattern is 5 ° C.
According to the ceramic heater used as the comparative example, the difference between the temperature near the right-angled bent pattern and the temperature near the spiral pattern was 10 ° C. to 15 ° C.
Therefore, according to the ceramic heater according to the present invention, it has been found that the temperature of the ceramic substrate can be made uniform.
According to this result, in the case of the ceramic heater having the above configuration, the radius of curvature is optimally about 1 to 15 mm. In addition, cracks did not occur in the thermal shock test in the examples, whereas cracks were observed in the comparative examples.
In addition, the following is considered. The radius of curvature is 20m
If m is exceeded, the temperature difference will increase. This is because the pattern formation density decreases. Therefore, the effect of the present invention is remarkable when the radius of curvature is in the range of 0.1 to 20 mm. This effect is more remarkable in aluminum nitride and silicon carbide than in alumina. This is because aluminum nitride and silicon carbide are more sensitive to the variation in the amount of heat generated, because they have better temperature followability (that is, the temperature rise time is shorter).

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

The semiconductor manufacturing / inspection apparatus according to the present invention
The ceramic heater for use can be used as an electrostatic chuck if electrodes are embedded in the ceramic substrate. Further, the ceramic heater for a semiconductor manufacturing / inspection apparatus according to the present invention can be used as a wafer prober by embedding a conductor layer on the surface of the ceramic substrate and burying electrodes inside.

[0042]

According to the present invention, a ceramic heater for a semiconductor manufacturing / inspection apparatus is provided on a surface of a disk-shaped ceramic substrate.
A heating element pattern is formed, and the heating element pattern
Heat the semiconductor wafer on the wafer heating surface opposite to the forming surface
A ceramic heater, wherein
The diameter is 200 mm or more, and the ceramic is a nitride
Ceramic or carbide ceramic alone or two or more
And a bending pattern on the outer edge
The bending pattern has a radius of curvature of 0.1 to 2
With a bend that bends by drawing a 0mm radius
Good pattern formation density can be obtained
In addition, the temperature followability is excellent, and the temperature reduction portion does not occur in the bent portion, and the temperature uniformity is excellent.

[Brief description of the drawings]

FIG. 1A is a plan view showing a main part of a ceramic heater according to an embodiment of the present invention, and FIG.
It is the elements on larger scale of the dotted line surrounding of (a).

FIG. 2 is a plan view showing an example of a heating element pattern of the ceramic heater according to one embodiment of the present invention.

FIG. 3 is a partially enlarged view showing a part of a heating element pattern of the ceramic heater according to one embodiment of the present invention in an enlarged manner.

FIG. 4 is a partial sectional view showing a structure of a ceramic heater according to one embodiment of the present invention.

FIG. 5 is a partially enlarged view showing a part of a heating element pattern of a conventional ceramic heater in an enlarged manner.

FIG. 6 is a plan view showing a main part of a ceramic heater used as a comparative example.

FIG. 7 is a photograph as a substitute for a drawing of a square ceramic heater.

FIG. 8 is a drawing substitute photograph of a thermoviewer.

FIGS. 9A and 9B are diagrams showing a configuration in a case where a heating element is integrally formed therein.

[Explanation of symbols]

 Reference Signs List 100 ceramic heater 1 ceramic substrate 2, 31, 31a heating element pattern

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI H05B 3/20 393 H01L 21/30 567 (58) Investigated field (Int.Cl. ⁷ , DB name) H05B 3/10 H01L 21 / 027 H05B 3/16 H05B 3/18 H05B 3/20 393 H01L 21/66 H01L 21/68

Claims (1)

(57) [Claims] 1. Heat is generated on the surface of a disk-shaped ceramic substrate.
Is formed on the wafer heating surface opposite to the heating element pattern formation surface.
Ceramic for semiconductor manufacturing and inspection equipment that heats conductive wafers
A heater, wherein the diameter of the ceramic substrate is 200 mm or more, and the ceramic is a nitride ceramic, a carbide ceramic,
And a bent pattern is disposed on the edge near the outer periphery, and the bent pattern has an curvature radius of 0.1 to 20 mm.
Characterized in that it has a bent portion that draws and bends
Ceramic heater for semiconductor manufacturing and inspection equipment.