JP3011528B2 - Ceramic heater for heating semiconductor and method of manufacturing the same - 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 heating a semiconductor which can be used in various semiconductor manufacturing apparatuses, etching apparatuses and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a heat source in a semiconductor manufacturing apparatus, a so-called stainless steel heater or an indirect heating type has been generally used. However, when these heat sources are used, there has been a problem that particles are generated due to the action of the halogen-based corrosive gas, and heat efficiency is poor. In order to solve such a problem, the present inventor has proposed a ceramic heater in which a wire made of a high melting point metal is embedded in a disc-shaped base made of dense ceramics. The wire is spirally wound inside the disc-shaped base, and terminals are connected to both ends of the wire.
It has been found that such a ceramic heater has excellent characteristics especially for semiconductor production.

[0003]

However, it has been found that some problems also occur in such a disc-shaped ceramic heater, particularly for manufacturing reasons. That is, in order to manufacture the above-described ceramic heater, first, a wire made of a high melting point metal is spirally wound, terminals (electrodes) are adhered to both ends of the wire, and annealed in a vacuum. On the other hand, a ceramic powder is charged in a press molding machine and pre-molded until a certain degree of hardness is obtained. Then, the wire is accommodated in the concave portion, and the ceramic powder is further filled thereon. Then, the ceramic powder is uniaxially pressed to form a disk-shaped molded body, and the disk-shaped molded body is subjected to hot press sintering.

However, when transporting the resistance heating element from the annealing apparatus to the preform, it is extremely difficult to transport the resistance heating element without losing its shape, and in many cases, it will inevitably lose its shape. In addition, after placing a resistance heating element in the recess of the preform, filling it with ceramic powder and performing uniaxial pressure molding, but at this time the filling density of the powder varies depending on the location, The resistance heating element is easily deformed. Furthermore, since a large pressure is applied in the thickness direction of the disk-shaped substrate at the time of hot pressing, even if the mold does not collapse at the time of molding,
The position of the resistance heating element may shift during hot pressing. When these phenomena occur, in any case, the temperature of the heater heating surface becomes uneven, and the heater characteristics are not constant.

[0005] In addition, the wire, which is a resistance heating element, is easily broken by the shearing force applied during hot pressing. In order to prevent this, it is necessary to impart considerable rigidity to the resistance heating element and the disk-shaped molded body. For this reason, it is necessary to increase the wire diameter of the linear resistance heating element and the thickness of the disc-shaped molded body to some extent. Due to these limitations, it is not possible to reduce the heat capacity by reducing the thickness of the heater and increase the calorific value, the response to changes in surface temperature is slow, and the rate of temperature rise is slow. I couldn't improve her.

SUMMARY OF THE INVENTION An object of the present invention is to ensure the uniformity of temperature and the stability of quality of a ceramic heater, to increase its productivity,
Another object is to improve the responsiveness of the heater by reducing the thickness of the base.

[0007]

According to the present invention, there is provided a ceramic heater for heating a semiconductor, comprising a base made of a dense sintered body made of ceramics selected from silicon nitride, aluminum nitride and sialon; A resistance heating element comprising a wound metal foil made of a high-melting point metal having a thickness of 25 μm to 50 μm embedded therein; and a board-shaped ceramic molded body in which the wound body is embedded. Wherein the main surface of the ceramic molded body is substantially flat, the wound body is buried substantially parallel to the main surface, and the uniaxial addition is performed in a direction perpendicular to the main surface. The present invention relates to a ceramic heater for heating a semiconductor, characterized in that a base is constituted by a pressed sintered body of a ceramic molded body that has been pressed.

Further, the present invention provides a substrate made of a dense sintered body made of ceramics selected from silicon nitride, aluminum nitride and sialon, and a substrate embedded in the substrate and having a thickness of 25 μm. When manufacturing a ceramic heater for semiconductor heating comprising a resistance heating element comprising a wound body of a metal foil made of a high melting point metal of about 50 μm, the wound body is embedded in ceramic powder, A disk-shaped ceramic molded body is produced by uniaxially pressing the molded body. At this time, the main surface of the ceramic molded body is substantially flat, and the wound body is substantially aligned with the main surface of the ceramic molded body. A semiconductive body characterized by forming a substrate and a resistance heating element in the substrate by pressure sintering the ceramic molded body. The present invention relates to a method for manufacturing a body heating ceramic heater.

In the present invention, the metal foil is wound so that the main surface of the metal foil is located on the same plane to obtain a wound body.
When the wound body is embedded in the ceramic molded body, it can be embedded such that the main surface of the metal foil is located in a direction substantially parallel to the main surface of the ceramic molded body. At this time, pressure is applied by applying pressure in a direction perpendicular to the main surface of the metal foil. In the present invention,
The wound body is embedded in ceramic powder, and then the powder is uniaxially pressed in a direction substantially parallel to the main surface of the metal foil to form a ceramic molded body. Can be located in a direction substantially perpendicular to the main surface of the ceramic molded body. Pressing this ceramic compact by cold isostatic pressing to shrink the wound body to obtain a pressed compact, and then subjecting the pressed compact to hot press sintering or hot isostatic press sintering Can be. As a pressure sintering method for molded products,
There are a sintering by a hot press method and a method of hot isostatic press sintering after normal pressure sintering.

[0010]

EXAMPLES (Example 1) First, as shown in FIG. 1 (a), a metal foil 1 made of a high melting point metal, for example, a rectangular plane is prepared. This thickness needs to be 25 to 50 μm for the reason described later. Next, the metal foil 1 is processed by sandblasting or etching to produce a resistance heating element 2 having a planar pattern as shown in FIG. 1B, for example. The resistance heating element 2 has a shape in which an elongated metal foil extends substantially parallel to the main surface of the metal foil, and therefore, the entire resistance heating element 2 is substantially on the same plane. At both ends of the resistance heating element 2, end portions 2a wider than other portions are formed.
A terminal mounting hole 2b is formed.

Next, the terminal 3 is attached to the end of the resistance heating element 2. In this case, for example, a male screw 3a is provided on the bottom surface of the cylindrical main body, and the male screw 3a is inserted into the terminal mounting hole 2b. The male screw 3 a is screwed into the female screw 4 a of the nut 4, the nut 4 is tightened, and the terminal 3 is fixed.

FIGS. 2A to 2D are cross-sectional views schematically showing a procedure for manufacturing a disk-shaped molded body. First, a ceramic powder is filled in the upper part of the lower mold 5A (inside of the frame 6) and press-formed once to obtain a preformed body 7. Next, the preform 7
The resistance heating element 2 is installed on the resistance heating element 2 at this time. Ceramic powder 8 is filled on the resistance heating element 2. Next, as shown in FIG. 2 (c), the ceramic powder is uniaxially pressed with the upper die 5B and the lower die 5A to obtain a disk-shaped molded body 9. Next, as shown in FIG. 2 (d), the lower die 5A is raised to take out the disk-shaped molded body 9.

Next, the disk-shaped molded body 9 is sintered under pressure to highly densify the ceramics, thereby obtaining a disk-shaped substrate. The back side of the disk-shaped substrate is ground to obtain a ceramic heater as shown in FIG. In FIG. 3, the resistance heating element 2 is buried inside the disk-shaped base 9A, and the pair of terminals 3 is exposed on the back surface 9a side. The disk-shaped molded body 9 is
It is preferable to perform sintering by a hot press method or sinter by a hot isostatic press method after preliminary sintering at normal pressure.

In this embodiment, a resistance heating element made of a metal foil is used, and the resistance heating element 2 is substantially in the same plane. For this reason, there is almost no problem that the resistance heating element collapses, and the transportation and installation on the preformed body 7 can be performed in a short time, so that productivity is greatly improved. Further, unlike the case of the wire, the planar shape is determined, so that the annealing treatment is unnecessary. Moreover, even in the case of normal pressure sintering, hot press sintering or HIP sintering, since the resistance heating element 2 has a predetermined planar shape, deformation and displacement of the resistance heating element hardly occurred. Therefore, the uniformity of the ceramic heater is improved, and the quality of the product is stabilized.

Moreover, since the resistance heating element is thin, the uniaxial pressure molding can be easily performed even if the thickness of the disk-shaped molded body 9 is reduced. Therefore, the disk-shaped substrate 9A can be made thinner than before, and the response to a rise and fall in temperature can be made faster.

As the dense ceramics constituting the disc-shaped substrate 9A, silicon nitride, aluminum nitride, or sialon is used. According to the study of the present inventors, the thermal shock resistance of the heater is high when silicon nitride is used. Also, when aluminum nitride is used, a high corrosion resistance effect can be obtained with respect to a halogen-based corrosive gas. The high melting point metal constituting the resistance heating element 2 is preferably tungsten or the like. Further, it is needless to say that the metal foil is not a porous material used for printing, vapor deposition and the like, but is dense.

According to the above-described procedure, a disk-shaped ceramic heater was manufactured as shown in FIGS. The thickness of the metal foil 1 made of tungsten was changed to 15, 25, 50, and 75 μm, and the effect was examined. The resistance heating element 2 was formed by sandblasting. The disk-shaped substrate 9A was formed of nitride ceramics. Processing by sandblasting was most easily performed when the thickness of the metal foil 1 was 25 μm and 50 μm. Also, when the thickness of the resistance heating element 2 was 25 μm or more, it was the easiest to handle. In each case, no deformation of the resistance heating element due to hot pressing was observed. When the thickness of the resistance heating element 2 was 15 μm, 25 μm, or 50 μm, the variation in the surface temperature of the disc-shaped ceramic heater was the smallest.

Embodiment 2 First, as shown in FIG. 4, an elongated metal foil 11 made of a dense high melting point metal is prepared.
In this example, the metal foil 11 is formed in a straight line, and is wound as shown in FIG. Then, the metal foil 11 is formed in accordance with a predetermined pattern to produce, for example, a planar resistance heating element 12 as shown in FIG. The resistance heating element 12 extends in a direction substantially perpendicular to the main surface of the metal foil, and forms a planar pattern.

For example, terminals as shown in FIG. 6 are fixed to both ends of the resistance heating element 12. In this example, a circular through-hole 13a is opened in the lower part of the cylindrical terminal 13, and the circular through-hole 13a is formed.
The female screw 13b is provided so as to be orthogonal to. And FIG.
As shown in (b), the end of the resistance heating element 12 is
Then, the male screw 14a of the bolt 14 is screwed into the female screw 13b, and the end of the resistance heating element 12 is crushed and locked by the tip of the bolt 14.

Next, as shown in FIGS. 7A to 7C, uniaxial pressure molding is performed. That is, the resistance heating element 12 is placed on the preform 7.
, And at this time, the terminal 13 is positioned above the resistance heating element 12. The ceramic powder 8 is filled on the resistance heating element 12. Next, as shown in FIG. 7 (b), the ceramic powder is uniaxially pressed with the upper die 5B and the lower die 5A to obtain a disk-shaped molded body 9. At this time, the ceramic powder is compressed in a direction substantially parallel to the main surface of the metal foil. Next, as shown in FIG. 7 (c), the lower die 5A is raised to take out the disk-shaped molded body 9.

Thereafter, there are two sintering methods. In the first method, the disc-shaped molded body 9 is subjected to normal pressure sintering, hot press sintering, or pre-sintering at normal pressure, followed by HIP sintering to densify the ceramics, and the I do.
The back side of the disk-shaped substrate is ground to obtain a ceramic heater as shown in FIG. In FIG. 8, a resistance heating element 12 is buried inside a disk-shaped base 9A, and a pair of terminals 13 are exposed on the back surface 9a side. In the second method,
The disk-shaped molded body 9 is densely molded by a cold isostatic press, and the molded body is sintered. As the sintering method, any of the sintering methods described above can be used.

In this embodiment as well, the transport and installation of the resistance heating element 12 is relatively easy, and the productivity is improved as compared with the prior art. In addition, there is little misalignment or deformation inside the molded body,
Product quality is stable. Further, compared to the case where a coil-shaped resistance heating element is formed by winding a wire, the shape of the resistance heating element is more stable, so that the disc-shaped molded body 9 can be made thinner.

Moreover, in the present embodiment, the disk-shaped molded body 9 can be subjected to cold isostatic press molding. That is, since the resistance heating element 12 can uniformly shrink in the radial direction toward the center of the disk-shaped molded body 9, the disk-shaped molded body 9 is cold-statically pressed (CIP).
Molding is possible even if pressure is applied to the surface of isotropically. For example, when a coil-shaped resistance heating element is used, the resistance heating element repels when pressure is applied in the radial direction.
Molding was difficult.

As described above, since the CIP molding can be adopted, a denser and higher-density molded body than before can be obtained, so that the characteristics of the disc-shaped substrate 9A as ceramics are improved. In addition, normal pressure sintering can be performed after CIP molding. In this case, hot press sintering becomes unnecessary. Therefore, compared to the case of hot press sintering, a large number of products can be sintered at normal pressure at a time, so that productivity is remarkably improved. However, if this point is ignored, hot press sintering and hot isostatic press sintering can also be used.

In the present invention, the planar shape of the disk-shaped substrate can be variously changed. In addition, two or more resistance heating elements can be embedded in a single disk-shaped substrate and heated in two zones.

[0026]

According to the present invention, in a ceramic heater, when a wound body of a dense metal foil made of a high melting point metal is embedded in the ceramic molded body, the wound body is placed on the main surface of the ceramic molded body. The ceramics compact is pressurized and sintered to form a heater. Therefore, the flatness of the wound body is high, and the deformation and displacement of the resistance heating element hardly occur as in the case of the linear resistance heating element. Is held high. Therefore, the thermal uniformity of the ceramic heater is improved. Moreover, the resistance heating element can be made thin,
In addition, since the shape of the resistance heating element is stable, uniaxial pressure molding can be easily performed even if the thickness of the molded body is reduced. Therefore, the substrate can be made thinner than before, and the response to a rise and fall in temperature can be made faster. Further, by setting the thickness of the metal foil to 25 μm or more, handling of the resistance heating element becomes easy, and by setting the thickness to 50 μm or less,
The temperature uniformity of the ceramic heater is significantly improved.

[Brief description of the drawings]

1A is a perspective view of a metal foil 1, and FIG. 1B is a resistance heating element 2.
FIG. 3C is a perspective view showing a state immediately before the terminal 3 is attached to the end of the resistance heating element 2.

FIGS. 2 (a), (b), (c) and (d) are cross-sectional views schematically showing respective manufacturing steps of a disk-shaped molded body 9. FIG.

FIG. 3 is a perspective view showing a disc-shaped ceramic heater.

FIG. 4 is a perspective view showing a metal foil 11;

FIG. 5 is a plan view showing the resistance heating element 12. FIG.

FIG. 6A is a front view of the terminal 13 and the bolt 14, and FIG.
FIG. 3 is a perspective view showing a state in which a terminal 13 is attached to an end of a resistance heating element 12.

FIGS. 7 (a), (b) and (c) are cross-sectional views schematically showing respective manufacturing steps of a disk-shaped molded body 9. FIGS.

FIG. 8 is a plan view showing a disc-shaped ceramic heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Metal foil 2, 12 Resistance heating element 3, 13 Cylindrical terminal 7 Preformed body 8 Ceramic powder 9 Disk shaped body 9A Disk shaped base

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) The inventor Yusuke Arai 2-38-2, Okamachi, Mizuho-ku, Nagoya-shi, Aichi Japan hill dormitory in Japan (56) References JP-A-3-261131 (JP, A) JP-A-3-245486 (JP, A) JP-A-63-81787 (JP, A) JP-B-54-20111 (JP, B2)

Claims (6)

(57) [Claims] 1. A ceramic heater for heating a semiconductor,
A base made of a dense sintered body made of ceramics selected from silicon nitride, aluminum nitride and sialon, and a metal made of a high melting point metal having a thickness of 25 μm to 50 μm embedded inside the base. A resistance heating element comprising a roll of foil, wherein the roll is embedded in a disc-shaped ceramic molded body, and the main surface of the ceramic molded body is substantially
Pressing of a ceramic molded body which has a flat surface, the wound body is buried substantially parallel to the main surface, and is uniaxially pressed in a direction perpendicular to the main surface. A ceramic heater for heating a semiconductor , wherein the base is constituted by a sintered body. 2. The method according to claim 1, wherein the metal foil is wound so that a main surface of the metal foil is located in a direction substantially parallel to the main surface of the ceramic molded body. The ceramic heater for heating a semiconductor according to claim 1. 3. The main surface of the metal foil is formed of the ceramics.
Position in a direction substantially perpendicular to the main surface of the compact
The ceramic heater for heating a semiconductor according to claim 1 , wherein the metal foil is wound so as to perform the heating. 4. A base made of a dense sintered body made of ceramics selected from silicon nitride, aluminum nitride, and sialon, and a high-density body having a thickness of 25 μm to 50 μm embedded in the base. semiconductors which a resistance heating body made of windings of the melting point metal of the metal foil
In the manufacture of the body for heating the ceramic heater, embedded the spirally wound body in the powder of the ceramic, and then disk-shaped sera by uniaxial pressing a pre Kikotai
A mixed molded body is produced, and at this time, the ceramic molding is performed.
The main surface of the body is substantially flat, the wound body is buried substantially parallel to the main surface of the ceramic molded body, and then the ceramic molded body is pressure-sintered. Thereby forming the substrate and a resistance heating element in the substrate. 5. A wound body is obtained by winding the metal foil so that a main surface of the metal foil is located on the same plane, and when the wound body is embedded in the ceramic molded body, The method of manufacturing a ceramic heater for heating a semiconductor according to claim 4, wherein the metal foil is embedded so that a main surface of the metal foil is positioned in a direction substantially parallel to the main surface of the ceramic molded body. 6. The ceramic material is embedded by burying the wound body in the ceramic powder and then uniaxially pressing the powder in a direction substantially parallel to a main surface of the metal foil. create a molded body, which by gold
The main surface of the metal foil is the main table of the ceramic molded body.
So as to be positioned in a direction substantially perpendicular to the plane, to obtain a pressed compact in the ceramic molded body by pressure molding by cold isostatic pressing to contract the wound body, then this pressurized The method for manufacturing a ceramic heater for heating a semiconductor according to claim 4, wherein the compact is subjected to hot press sintering or hot isostatic press sintering.