JP2004140347A - Wafer holder and semiconductor manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer holder, which prevents breakage of a fixed tubular body and/or a fixed supporter caused by thermal stress in heating treatment and a highly reliable semiconductor manufacturing device, using the wafer holder. <P>SOLUTION: One end of at least two fixed tubular bodies 5 and/or fixed supporters is fixed to a ceramics heater 2, and the other end thereof is fixed to a reaction container 4. When the highest attained temperature of the ceramics heater 2 is T1, the thermal expansion coefficient of the ceramics heater 2 is α1; when the highest attained temperature of the reaction container 4 is T2, the thermal expansion coefficient of the reaction container 4 is α2; and when the longest distance between a plurality of fixed tubular bodies 5 and/or fixed supporters on the ceramics heater 2 at a normal temperature is L1 and the longest distance between a plurality of fixed tubular bodies 5 and/or fixed supporters on the reaction container 4 at a normal temperature is L2, the relational expression ¾(T1×α1×L1)-(T2×α2×L2)¾≤0.7mm is satisfied. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a wafer holder used for plasma CVD, low-pressure CVD, low-k film baking, plasma etching, insulating film CVD, and the like in a semiconductor manufacturing process, and a semiconductor manufacturing apparatus provided with the wafer holder.

Conventionally, various types of semiconductor manufacturing apparatuses for performing processes such as film formation and etching on a semiconductor wafer have been proposed. In these semiconductor manufacturing apparatuses, a wafer holder having a resistance heating element is provided in a reaction vessel, and various processes are performed while holding and heating a wafer on the wafer holder.

For example, Japanese Patent Publication No. 6-28258 discloses a ceramic heater section in which a resistance heating element is buried, installed in a reaction vessel and provided with a wafer heating surface, and a surface of the heater section other than the wafer heating surface. And a convex support portion forming an airtight seal with the reaction vessel, and connected to the resistance heating element and taken out of the reaction vessel so as not to be substantially exposed to the internal space of the reaction vessel. A semiconductor wafer heating device having an electrode member has been proposed.

Also, Japanese Patent No. 2525974 proposes a structure in which a plurality of cylindrical bodies are joined and supported on a ceramic heater (wafer holding body). This structure is an improvement of the ceramic heater described in Japanese Patent Publication No. 6-28258. At least one of the electrode members provided on the ceramic heater is surrounded by a cylindrical body made of an inorganic insulating material. One end of the body is air-tightly joined to the ceramic heater, and the other end is inserted into a through hole provided in the reaction vessel to be air-tightly sealed.

Japanese Patent Publication No. 6-28258 Japanese Patent No. 2525974

The wafer heating device described in Japanese Patent Publication No. 6-28258 is a device in which a convex support portion is attached to a ceramic heater, but the convex support itself has a relatively large heat capacity to support the ceramic heater. As a result, a large amount of heat escapes from the ceramic heater, and the uniformity of the heated surface of the wafer is impaired.

Further, in the wafer heating apparatus disclosed in Japanese Patent No. 2525974, since a plurality of cylindrical bodies are bonded and fixed to the ceramic heater, the stress applied to the cylindrical bodies during the heating process increases. There was a risk that the body would be destroyed. That is, when the temperature of the ceramic heater rises to a certain temperature, the distance between the cylindrical bodies fixed to the ceramic heater increases due to thermal expansion of the ceramic heater. On the other hand, the reaction vessel in which the other end of the cylindrical body is inserted also expands due to the heat transferred from the ceramic heater and the cylindrical body. At this time, if the difference in the amount of thermal expansion between the ceramic heater and the reaction vessel is large, the stress applied to the cylindrical body may be increased and the tubular body may be damaged.

In particular, in recent years, silicon wafers have been increasing in diameter, and it has been required to uniformly heat a 12-inch silicon wafer. Accordingly, ceramic heaters for heating wafers are also increasing in size, so that thermal stress applied to the cylindrical body during heating of the ceramic heater is increased, and the fixed cylindrical body is more likely to be damaged. I have.

In addition, the temperature of the ceramic heater, which has been increased in size, is divided into a plurality of blocks (areas) to be heated, and accordingly, a temperature measuring element for measuring the temperature of the heater and electric power are supplied to the heater. The number of electrode terminals and leads for supply is also increasing. For this reason, the number of hollow cylindrical bodies for accommodating them is also increased, and in some cases, a solid columnar body is also installed, so that the risk of damage to the cylindrical body or the columnar body is further increased.

In view of such a conventional situation, the present invention provides a wafer holder capable of preventing a plurality of cylindrical bodies and / or columnar bodies fixed to a ceramic heater from being damaged by thermal stress during a heat treatment. And a highly reliable semiconductor manufacturing apparatus using the wafer holder.

In order to achieve the above object, a wafer holder provided by the present invention is a wafer holder for holding and processing a semiconductor wafer on a ceramics heater supported by a cylindrical body in a reaction vessel, At least two of the cylindrical bodies are fixed cylindrical bodies having one end fixed to the ceramic heater and the other end fixed to the reaction vessel,
The maximum temperature reached by the ceramic heater is T1,
The coefficient of thermal expansion of the ceramic heater is α1,
The maximum temperature of the reaction vessel is T2,
The thermal expansion coefficient of the reaction vessel is α2,
The longest distance on the ceramic heater at room temperature between the fixed cylindrical bodies is L1,
When the longest distance on the reaction vessel at normal temperature between the fixed cylindrical bodies is L2,
| (T1 × α1 × L1) − (T2 × α2 × L2) | ≦ 0.7 mm
Is satisfied.

Another wafer holder provided by the present invention is a wafer holder for holding and processing a semiconductor wafer on a ceramic heater supported by a cylindrical body and / or a support in a reaction vessel, At least two of the cylindrical body and / or the support are a fixed cylindrical body and / or a fixed support having one end fixed to the ceramic heater and the other end fixed to the reaction vessel,
The maximum temperature reached by the ceramic heater is T1,
The coefficient of thermal expansion of the ceramic heater is α1,
The maximum temperature of the reaction vessel is T2,
The thermal expansion coefficient of the reaction vessel is α2,
The longest distance on the ceramic heater at room temperature between the fixed cylindrical body and / or the fixed support is L1,
When the longest distance on the reaction vessel at normal temperature between the fixed cylindrical body and / or the fixed support is L2,
| (T1 × α1 × L1) − (T2 × α2 × L2) | ≦ 0.7 mm
Is satisfied.

In the above-described wafer holder of the present invention, the ceramic heater may have a thermal expansion coefficient of 8.0 × 10 ⁻⁶ / K or less and a reaction vessel may have a thermal expansion coefficient of 15 × 10 ⁻⁶ K or more. preferable. More preferably, the ceramic heater has a thermal expansion coefficient of 6.0 × 10 ⁻⁶ / K or less, and the reaction vessel has a thermal expansion coefficient of 20 × 10 ⁻⁶ K or more.

In the wafer holder of the present invention, it is preferable that the length of the fixed tubular body and / or the fixed support from the ceramic heater to the reaction vessel is 320 mm or less. Further, the length of the fixed cylindrical body and / or the fixed support from the ceramic heater to the reaction vessel is 150 mm or less, and the thermal conductivity of the fixed cylindrical body and / or the fixed support is 30 W / mK. The following is preferred.

In the above-described wafer holder of the present invention, it is preferable that the reaction vessel is not water-cooled. Further, in the above-described wafer holder of the present invention, it is preferable that a reflection plate for reflecting heat of the ceramic heater is provided between the reaction container and the ceramic heater.

In the wafer holder of the present invention, it is preferable that the parallelism of each of the fixed cylindrical body and / or the fixed support having both ends fixed to the reaction vessel side and the ceramic heater side is within 1.0 mm. More preferably, the parallelism of each of the fixed tubular body and / or the fixed support is within 0.2 mm.

The wafer holder of the present invention is provided with an O-ring fixed to the reaction vessel and for maintaining airtightness outside the reaction vessel, and a contact surface of the cylindrical body and / or the support with the O-ring. The surface roughness in the vicinity is preferably 5.0 μm or less in Ra. The surface roughness of the cylindrical body and / or the support near the contact surface with the O-ring is more preferably not more than 1.0 μm in Ra, particularly preferably not more than 0.3 μm in Ra. .

The wafer holder of the present invention is provided with an O-ring fixed to the reaction vessel and for maintaining airtightness outside the reaction vessel, and a contact surface of the cylindrical body and / or the support with the O-ring. It is preferable that the size of the surface defect existing in the vicinity is 1 mm or less in diameter. The size of the surface defect existing near the contact surface of the cylindrical body and / or the support with the O-ring is more preferably 0.3 mm or less in diameter, and is 0.05 mm or less in diameter. Particularly preferred.

In the above-described wafer holder of the present invention, the parallelism between the ceramic heater and the bottom of the reaction vessel is preferably within 1.0 mm, and furthermore, the parallelism between the ceramic heater and the bottom of the reaction vessel is more preferable. More preferably, the degree is within 0.2 mm.

In the wafer holder of the present invention, the length of the fixed cylindrical body and / or the fixed support to the reaction vessel is 150 mm or less, and the heat of the fixed cylindrical body and / or the fixed support is not more than 150 mm. Preferably, the conductivity is 30 W / mK or less. Further, it is preferable that the reaction vessel is not water-cooled.

In the wafer holder of the present invention, the main component of the ceramic heater is preferably one of alumina, silicon nitride, aluminum nitride, and silicon carbide. In addition, the main component of the ceramic heater is aluminum nitride, the main component of the reaction vessel is aluminum or an aluminum alloy, and the main component of the fixed cylindrical body and / or the fixed support is mullite or a mullite-alumina composite. Is more preferred.

The present invention also provides a semiconductor manufacturing apparatus having the above-mentioned wafer holder mounted thereon. This semiconductor manufacturing apparatus is preferably used for firing a Low-k film.

According to the present invention, the electrode terminals and leads for supplying power to the ceramic heater, and further, the cylindrical body containing the temperature measuring element and the support for supporting the ceramic heater are fixed to the ceramic heater and the reaction vessel. Thus, it is possible to provide a wafer holder which can be prevented from being damaged even when it is damaged and which can greatly improve reliability, and a semiconductor manufacturing apparatus using the same.

The wafer holder 1 according to the present invention includes, for example, as shown in FIG. 1-1, a ceramic heater 2 having a resistance heating element 3 and a plurality of cylindrical bodies supporting the ceramic heater 2 in a reaction vessel 4. I have. Two or more of these tubular bodies are fixed tubular bodies 5 having one end fixed to the ceramic heater 2 by joining or the like, and the other end fixed to the reaction vessel 4 by an O-ring 6 or the like. Note that inside the fixed cylindrical body 5, there are provided electrode terminals and leads 7 for supplying power to the resistance heating element 3 of the ceramic heater 2 in the wafer holder 1, or a temperature for measuring the temperature of the wafer holder 1. The measuring element 8 can be accommodated.

Further, as another embodiment of the wafer holder 1 according to the present invention, as shown in FIG. 1-2, for example, a ceramic heater 2 having a resistance heating element 3 and a plurality of supporting the ceramic heater 2 in a reaction vessel 4 are provided. Cylindrical body and / or support. Two or more of these cylindrical bodies and / or supports are fixed cylindrical bodies having one end fixed to the ceramic heater 2 by joining or the like, and the other end fixed to the reaction vessel 4 by an O-ring 6 or the like. The body 5 and / or the fixed support 5a. Also in this case, inside the fixed cylindrical body 5, an electrode terminal or lead 7 for supplying power to the resistance heating element 3 of the ceramic heater 2 in the wafer holder 1 or the like, or a temperature of the wafer holder 1 is measured. Can be accommodated.

As described above, the ceramic heater 2 of the wafer holder 1 may be supported by a cylindrical body capable of containing the temperature measuring element 8 such as an electrode terminal, a lead 7, and a thermocouple, or may be a support other than these cylindrical bodies. A member, for example a solid support, may be provided. It is also possible to use a cylindrical body and / or a support that is not fixed to the ceramic heater 2 and / or the reaction vessel 4. Also in these cases, the subject of the present invention is a fixed cylindrical body and a fixed support fixed to the ceramic heater and the reaction vessel.

The fixed cylindrical body 5 and / or the fixed support 5a fixed to the ceramic heater 2 are heated by heat applied to the ceramic heater 2 during wafer processing, and the heat is applied to the fixed cylindrical body 5 and / or the fixed support. 5a is transmitted to the reaction vessel 4. In addition, heat is transmitted to the reaction vessel 4 by heat radiation, radiation, and convection from the ceramic heater 2. Therefore, the ceramic heater 2 and the reaction vessel 4 thermally expand. At this time, the fixed cylindrical body 5 and / or the fixed support 5a receive stress according to the difference in the amount of thermal expansion between the ceramic heater 2 and the reaction vessel 4, and breakage occurs when the stress is large.

A detailed study of the relationship between the amount of thermal expansion of the ceramic heater and the reaction vessel and the damage to the fixed cylindrical body and / or the fixed support revealed that when the difference between the two thermal expansion amounts exceeded 0.7 mm, It was found that the body and / or the fixed support were damaged by stress. For this reason, in the wafer holder of the present invention, the difference in the longest distance between the plurality of fixed cylindrical bodies and / or the fixed supports on the ceramic heater and the reaction vessel is set to 0.7 mm when the maximum temperature is reached. It is set in advance as follows.

That is, in the present invention, as shown in FIG. 1-1, for example, a ceramic heater 2 having a resistance heating element 3 is supported in a reaction vessel 4 by a plurality of fixed cylindrical bodies 5, In the wafer holder 1 whose end side is hermetically sealed to the reaction vessel 4 by an O-ring 6,
The maximum temperature reached by the ceramic heater 2 is T1,
The thermal expansion coefficient of the ceramic heater 2 is α1,
The maximum temperature of the reaction vessel 4 is T2,
The thermal expansion coefficient of the reaction vessel 4 is α2,
The longest distance on the ceramic heater 2 at room temperature between the fixed cylindrical bodies 5 is L1,
When the longest distance on the reaction vessel 4 at normal temperature between the fixed cylindrical bodies 5 is L2,
| (T1 × α1 × L1) − (T2 × α2 × L2) | ≦ 0.7 mm
L1 and L2 are set so as to satisfy the relational expression.

In the present invention, for example, as shown in FIG. 1-2, in a wafer holder 1 in which a ceramic heater 2 is supported by a cylindrical body and / or a support in a reaction vessel, power is supplied to the wafer holder 1. At least two of an electrode terminal, a lead, and / or a cylindrical body including a temperature measuring element for measuring the temperature of the wafer holder, and a support for supporting the wafer holder have one end. When the fixed cylindrical body 3 and / or the fixed support 3a are fixed to the ceramic heater and the other end side to the reaction vessel,
The maximum temperature T1 of the ceramic heater 2, the thermal expansion coefficient α1 of the ceramic heater 2, the maximum temperature T2 of the reaction vessel 4, the thermal expansion coefficient α2 of the reaction vessel 4, the fixed cylindrical member 5 and / or the fixed support 5a The longest distance L1 on the ceramic heater 2 at room temperature and the longest distance L2 between the fixed cylindrical body 5 and / or the fixed support 5a on the reaction vessel 4 at room temperature are:
Relational expression: | (T1 × α1 × L1) − (T2 × α2 × L2) | ≦ 0.7 mm
L1 and L2 are set so as to satisfy the following.

Here, the distance between the fixed tubular body and / or the fixed support (including the distance between the fixed tubular bodies in FIG. 1-1, the same applies hereinafter) is set to each outer dimension, and is set on the ceramic heater joined. And the distance on the reaction vessel is measured. In the above relational expression, (T1 × α1 × L1) represents the longest distance between the fixed cylindrical body and / or the fixed support on the ceramic heater when the ceramic heater reaches the maximum temperature, and (T2 × α2 × L2) represents the longest distance between the fixed cylindrical body and / or the fixed support on the reaction vessel when the ceramic heater reaches the maximum temperature.

Generally, the cylindrical body and / or the columnar body are fixed so as to be orthogonal to the ceramic heater and the reaction vessel, respectively. Therefore, two fixed cylindrical bodies and / or fixed bodies on the ceramic heater side and the reaction vessel side are used. The distance between the supports is usually the same. Even in such a case, at the time of heating the ceramic heater, the longest distance between the plurality of fixed cylindrical bodies and / or the fixed supports may be changed between the ceramic heater side and the reaction vessel side due to a difference in thermal expansion coefficient between the ceramic heater and the reaction vessel. And naturally it will be different.

Therefore, according to the present invention, when the ceramic heater is supported only by the cylindrical body as shown in FIG. 1-1, when the ceramic heater is heated, the longest distance between the plurality of fixed cylindrical bodies is obtained from the above-described relational expression. If the difference | (T1 × α1 × L1) − (T2 × α2 × L2) | is larger than 0.7 mm, for example, if the longest distance on the side of the reaction vessel is longer by 1.0 mm, it is necessary to set the temperature at room temperature in advance. By setting the distance between the solid cylindrical bodies on the ceramic heater side longer than the reaction vessel side by 0.3 mm or more during heating, the longest distance between the fixed cylindrical bodies even when the maximum temperature is used. Can be suppressed to within 0.7 mm. Conversely, when the longest distance on the ceramic heater side is longer, the distance on the reaction vessel side at room temperature is made longer than that on the ceramic heater side to satisfy the above relational expression and prevent the fixed cylindrical body from being damaged. Can be.

The present invention can also be applied to a case where the ceramic heater is not supported only by the tubular body, for example, a case where the ceramic heater is supported by the support as shown in FIG. Even in such a case, the cylindrical body including the electrode terminals for supplying power to the wafer holder, the leads, and / or the temperature measuring element for measuring the temperature of the wafer holder, and the wafer holder are supported. When at least two of the supporting members are a fixed cylindrical body and / or a fixed supporting member having one end fixed to the ceramic heater and the other end fixed to the reaction vessel, when the ceramic heater is heated, When the difference | (T1 × α1 × L1) − (T2 × α2 × L2) | between the plurality of fixed cylindrical bodies and / or the longest distance between the fixed supports is larger than 0.7 mm, for example, the longest distance on the reaction vessel side If the distance is longer by 1.0 mm, the distance between the solid cylindrical bodies on the ceramic heater side at room temperature should be set so as to be longer than the reaction vessel side by 0.3 mm or more at the time of heating. By the highest Even when the maximum temperature is used, the difference in the longest distance between the fixed cylindrical body and / or the fixed support can be suppressed to 0.7 mm or less. On the other hand, when the longest distance on the ceramic heater side is longer, the distance on the reaction vessel side at room temperature is made longer than that on the ceramic heater side so that the above relational expression is satisfied and the fixed cylindrical body and the fixed support are Damage can be prevented.

加熱 When the ceramic heater is heated, the relative positions of the plurality of fixed cylindrical bodies and / or the fixed supports change due to thermal expansion of the ceramic heater and the reaction vessel. As a result, in general, the rubber O-ring attached between the fixed cylindrical body and / or the fixed support and the reaction vessel may be deformed, and the airtightness in the reaction vessel may be slightly reduced. There is.

However, also in this case, the difference in the longest distance between the fixed cylindrical body and / or the fixed support in the above relational expression is 0.3 mm or less, that is, | (T1 × α1 × L1) − (T2 × α2 × L2). It is more preferable to set | ≦ 0.3 mm because the airtightness hardly decreases. Specifically, when the difference in the longest distance between the fixed cylindrical body and / or the fixed support is 0.3 mm or less, a value of 10 ⁻⁹ Pam ³ / s or less can be secured as the helium leak rate. it can. Further, even when the difference in the longest distance between the fixed cylindrical body and / or the fixed support is 0.7 mm or less, a value of 10 ⁻⁷ Pam ³ / s or less can be secured. In general, when the inside of the reaction vessel is evacuated at room temperature, there is no problem in airtightness.

筒 The tubular body in the present invention can house a temperature measuring element, a lead or an electrode terminal for supplying power to the resistance heating element, and may have any shape as long as it is tubular. On the other hand, the support in the present invention only needs to be able to support the ceramic heater, and the shape thereof is not particularly limited, such as a columnar shape, a prismatic shape, and a cylindrical shape. Further, the tubular body and the support need not be fixed to the ceramic heater and the reaction vessel, and the tubular body and the support in that case are not applied to the present invention. Further, with respect to the method of fixing the ceramic heater and the fixed cylindrical body and / or the fixed support, the fixing method is such that the distance between the fixed cylindrical body and / or the fixed support changes with the thermal expansion of the ceramic heater. If so, all fixing methods can be applied.

For example, as shown in FIGS. 2-1 and 2-2, the fixed cylindrical body 5 and / or the fixed support 5a are bonded to the surface (back surface) of the ceramic heater 2 opposite to the wafer heating surface with the glass 10. As shown in FIG. 3A and FIG. Further, as shown in FIGS. 4-1 and 4-2, a female screw is formed on the back surface of the ceramic heater 2 and a male screw of the fixed cylindrical body 5 and / or the fixed support 5a is screwed therein. It may be fixed with a screw 12. Further, as shown in FIGS. 5-1 and 5-2, a counterbore portion 13 is formed on the back surface of the ceramic heater 2, and one end of the fixed cylindrical body 5 and / or the fixed support 5a is fitted therein and fixed. You can also. Further, as shown in FIGS. 6-1 and 6-2, the fixed tubular body 5 and / or the fixed support 5a can be formed integrally with the ceramic heater 2. As for the fixed cylindrical body, the ceramic heater can be directly supported only by the fixed cylindrical body, or a separate support can be provided in addition to the fixed cylindrical body.

On the other hand, between the cylindrical body and / or the support and the reaction vessel, an O-ring or other method is used to keep the inside of the reaction vessel at a vacuum or reduced pressure when the ceramic heater is heated (at the time of wafer processing). The structure is such that the inside of the reaction vessel can be kept airtight.

The thermal expansion coefficient of the ceramic heater is preferably 8.0 × 10 ⁻⁶ / K or less, and the thermal expansion coefficient of the reaction vessel is preferably 15 × 10 ⁻⁶ / K or more. The reason why the coefficient of thermal expansion of the reaction vessel is made larger than that of the ceramic heater is that the temperature of the ceramic heater is relatively higher than the temperature of the reaction vessel during heating of the ceramic heater. This is because the amounts of thermal expansion of the two containers are matched by increasing the amount of thermal expansion of the container. Further, if the coefficient of thermal expansion of the ceramic heater is set to 6 × 10 ⁻⁶ / K or less and the coefficient of thermal expansion of the reaction vessel is set to 20 × 10 ⁻⁶ / K or more, the usage range of the ceramic heater temperature and the fixed cylindrical body And / or less restrictions on the mounting position of the fixed support are particularly preferred.

Reaction vessels are particularly demanded to be miniaturized in recent years. Therefore, it is preferable that the thermal conductivity of the cylindrical body or the support is 200 W / mK or less, because the length from the ceramic heater to the reaction vessel can be 320 mm or less. Conversely, when the thermal conductivity of the cylindrical body or the support exceeds 200 W / mK, the heat generated by the ceramic heater is transmitted through the cylindrical body or the support to raise the temperature of the reaction vessel, and the heat resistance temperature of the O-ring And it becomes difficult to keep the inside of the reaction vessel airtight, which is not preferable.

Further, as for the reaction vessel, if a water-cooling device is attached, the structure of the device becomes complicated. The length (distance) of the fixed cylindrical body and / or the fixed support from the ceramic heater to the reaction vessel is preferably 150 mm or less. This is because the longer the length of the cylindrical body and / or columnar body, the larger the size of the reaction vessel itself.

In order to set the above-mentioned length of the fixed tubular body and / or the fixed support to 150 mm or less without water cooling of the reaction vessel, heat transfer from the fixed tubular body and / or the fixed support to the reaction vessel is required. Need to be suppressed. For this reason, the thermal conductivity of the fixed cylindrical body and / or the fixed support is preferably 30 W / mK or less. Further, by setting the thermal conductivity of the fixed tubular body and / or the fixed support to 30 W / mK or less, the amount of heat escaping from the ceramic heater to the fixed tubular body and / or the fixed support can be reduced. The uniformity of the heater on the wafer heating surface can be improved.

From the viewpoint of heat uniformity, as a specific material of the cylindrical body and / or the support, alumina, mullite, a composite of alumina and mullite, stainless steel, or the like can be used. By using such a material, the length of the tubular body and / or the support to the reaction vessel is within 150 mm, water cooling is not used for the reaction vessel, the structure is simple, and miniaturization is achieved. It is possible to provide a semiconductor manufacturing apparatus which is possible and has excellent heat uniformity of a wafer heating surface.

In addition, what is housed in the cylindrical body includes a lead for supplying power to the resistance heating element of the ceramic heater, an RF electrode for generating plasma, and an electrostatic chuck electrode for fixing the wafer. And the like. Further, a temperature measuring element for measuring the temperature of the ceramic heater is also included in this.

反射 Also, it is possible to install a reflector between the reaction vessel and the ceramic heater to reflect the heat of the ceramic heater. Since the heat of the ceramic heater is reflected by installing the reflector, the power consumption of the ceramic heater can be reduced. In this case, there is no particular limitation on the position where the reflector is installed, but a side closer to the ceramics heater than a middle point between the bottom surface of the reaction vessel and the ceramics heater is preferable because it can efficiently reflect heat.

表面 The surface roughness of the reflection plate is preferably not more than 1.0 μm in Ra. It is not preferable that the surface roughness of the reflector is higher than that of the heat radiated from the ceramic heater, the ratio of heat absorbed by the reflector increases. In particular, it is particularly preferable that the surface is in a mirror state, that is, Ra is 0.1 μm or less. In addition, the material of the reflection plate is particularly inert as long as the material is inert to a gas used in the reaction vessel and has a heat resistance that does not cause deformation or the like with respect to a use temperature of the ceramic heater. There are no restrictions. For example, metals such as aluminum, stainless steel, and nickel, and ceramics such as alumina, silicon carbide, silicon nitride, and aluminum nitride are exemplified.

Further, the parallelism of the fixed cylindrical body and / or the fixed support having both ends fixed to the reaction vessel side and the ceramic heater side is preferably within 1.0 mm. If the degree of parallelism is further increased, when the wafer holder is mounted on the reaction vessel, extra stress is applied to the fixed cylindrical body and / or the fixed support fixed to the ceramic heater, which may cause breakage, which is not preferable. . If the degree of parallelism is within 1.0 mm when the fixed cylindrical body and / or the fixed support fixed to the ceramic heater is attached to the reaction vessel, deformation of the O-ring for airtight sealing attached to the reaction vessel side. By the function, the stress generated between the fixed cylindrical body and / or the fixed support and the ceramic heater can be reduced, and breakage can be prevented. In particular, when the parallelism is within 0.3 mm, the hermetic seal by the O-ring can be reduced to a helium leak rate of 10 ⁻⁹ Pam ³ / s or less, which is particularly preferable.

In addition, an O-ring is used for an airtight seal between the reaction vessel and the cylindrical body and / or the support. At this time, the surface roughness of the cylindrical body and / or the support near the contact surface where the O-ring contacts the cylindrical body and / or the support is preferably Ra ≦ 5.0 μm. In the case where the surface roughness is more than this, even if vacuum grease is used near the O-ring contact surface of the cylindrical body and / or the support, a vacuum degree of 10 ⁻⁷ Pam ³ / s or less is achieved. Is not preferred because it is very difficult. If Ra ≦ 5.0 μm, a vacuum degree of 10 ⁻⁷ Pam ³ / s or less can be achieved by using vacuum grease. Furthermore, if the surface roughness of the contact surface is Ra ≦ 1.0 μm, a vacuum degree of 10 ⁻⁷ Pam ³ / s or less can be achieved without using vacuum grease. Further, Ra ≦ 0.3 μm is particularly preferable because a vacuum degree of 10 ⁻⁹ Pam ³ / s or less can be achieved without using vacuum grease.

Further, an O-ring used for hermetic sealing between the cylindrical body fixed to the reaction vessel and / or the support is provided in a cylindrical shape in the vicinity of an abutting surface in contact with the cylindrical body and / or the support. It is preferable that the size of the surface defect of the body and / or the support is 1.0 mm or less in diameter. If a larger defect is present near the contact surface, it is not preferable because it is very difficult to achieve a degree of vacuum of 10 ⁻⁷ Pam ³ / s or less even when vacuum grease is used. If the size of the defect is 1.0 mm or less in diameter, a vacuum degree of 10 ⁻⁷ Pam ³ / s or less can be achieved by using vacuum grease. Furthermore, if the size of the defect existing near the contact surface is 0.3 mm or less in diameter, a degree of vacuum of 10 ⁻⁷ Pam ³ / s or less can be achieved without using vacuum grease. Further, when the size of the defect is 0.05 mm or less in diameter, it is particularly preferable because a degree of vacuum of 10 ⁻⁹ Pam ³ / s or less can be achieved without using vacuum grease.

平行 The parallelism between the ceramic heater and the bottom of the reaction vessel is preferably within 1.0 mm. If the parallelism exceeds this, the wafer may drop when the wafer is detached from the wafer holder, which is not preferable. That is, when the wafer is mounted on the wafer holder, usually three lift pins support the wafer in the space above the ceramic heater. At this time, the plane formed at the tip position of the lift pin is set to be parallel to the reaction vessel. Then, the wafer is mounted on the wafer mounting surface of the ceramic heater by lowering the three lift pins.

However, if the parallelism between the ceramic heater and the reaction vessel at this time exceeds 1.0 mm, the wafer will contact the ceramic heater before the lift pins descend. For this reason, the wafer is supported by the two lift pins and the wafer mounting surface of the ceramic heater. However, when the lift pins are lowered, the wafer may be inclined and fall or the mounting position of the wafer may be shifted. . If the parallelism between the ceramic heater and the reaction vessel is 1.0 mm or less, there is no danger of falling, and if the parallelism is 0.2 mm or less, it is particularly preferable because a positional shift that does not hinder wafer processing occurs. In addition, the displacement of the wafer means, for example, that the wafer runs over the edge of the wafer pocket formed on the wafer mounting surface.

材質 The material of the ceramic heater used in the present invention is not particularly limited, but a material mainly containing any of alumina, silicon nitride, aluminum nitride, and silicon carbide is preferable. In recent years, there has been a strong demand for ceramic heaters to have a uniform temperature distribution. Therefore, materials having high thermal conductivity, specifically, aluminum nitride and silicon carbide having a thermal conductivity exceeding 100 W / mK are preferable, and aluminum nitride has high corrosion resistance. It is particularly preferable because of its excellent insulating properties. Since silicon nitride has higher strength at high temperatures than other ceramics, it is particularly suitable for use at high temperatures. Furthermore, silicon nitride, aluminum nitride, and silicon carbide are excellent in thermal shock resistance, and can rapidly raise and lower the temperature. Also, alumina has a feature that it is superior in cost as compared with other ceramics. Of course, these ceramics need to be properly used depending on the application.

Regarding the material of the ceramic heater described above, aluminum nitride and silicon carbide are preferable because of the recent demand for uniformity of the wafer holder, and aluminum nitride having high corrosion resistance to various corrosive gases to be used is particularly preferable. The amount of the sintering aid contained in the aluminum nitride is particularly preferably from 0.05% by weight to 3.0% by weight. If the amount of the sintering aid is smaller than this, gaps exist between the particles of the aluminum nitride sintered body, and etching proceeds from the gaps, which is not preferable because particles are generated. If the amount of the sintering aid exceeds 3.0% by weight, the aid component exists at the grain boundaries of the aluminum nitride particles, and is etched from the aid component, and in this case, particles are generated.

材質 There are no particular restrictions on the material of the reaction vessel. For example, as the metal, aluminum, an aluminum alloy, nickel, a nickel alloy, and stainless steel can be used. Further, as the ceramic, alumina, cordierite or the like can be used, but there is no particular limitation.

材質 The material of the cylindrical body is preferably an insulator, especially when the cylindrical body includes a lead for supplying power to the resistance heating element, the RF electrode, and the electrostatic chuck electrode. When electrical conduction is formed between the tubular body and the lead, problems such as sparks being generated between the electrodes and conduction to the reaction vessel under reduced pressure and vacuum occur. Or to do so. Specifically, inorganic materials such as ceramics are preferable.

Among these cylindrical bodies, the fixed cylindrical body fixed to the ceramic heater has a coefficient of thermal expansion between the fixed cylindrical body and the ceramic heater when bonded with glass or brazing material. The smaller the difference, the better. Specifically, it is preferable that the difference between the thermal expansion coefficient of the fixed cylindrical body at room temperature and the thermal expansion coefficient of the ceramic heater at room temperature is 5.0 × 10 ⁻⁶ / K or less. If there is a difference in thermal expansion coefficient exceeding the difference between the two, the ceramic heater or the fixed cylindrical body may be damaged or cracked at the time of joining, which is not preferable. However, this is not the case when the tubular body is not directly joined to the ceramic heater and is fixed by screws or the like.

With regard to the specific material of the cylindrical body, it is possible to use the same material as that of the ceramic heater, but it is also possible to use mullite, alumina, sialon, silicon nitride or the like. These materials are preferable because they have relatively low thermal conductivity and can reduce the amount of heat transferred from the ceramics to the reaction vessel. In addition, even if it is a cylindrical body, when a lead etc. are not included, there is no restriction in particular in the material.

On the other hand, there is no particular limitation on the material of the support. Various materials such as various ceramics and metals, or composites of ceramics and metals can be used. That is, it may be appropriately selected according to the use environment of the Lamix heater.

Among these supports, the material of the fixed support fixed to the ceramic heater, when joined by glass or brazing material, has a smaller coefficient of thermal expansion between the fixed support and the ceramic heater. Is good. Specifically, the difference between the coefficient of thermal expansion of the fixed support at room temperature and the coefficient of thermal expansion of the ceramic heater at room temperature is preferably 5.0 × 10 ⁻⁶ / K or less. If a difference in thermal expansion coefficient exceeding this is present between the two, it is not preferable because the ceramics heater or the fixed support is damaged or cracks occur at the time of joining. However, this is not the case when the support is not directly joined to the ceramic heater and is fixed by screws or the like.

With regard to the specific material of the support, it is possible to use the same material as the ceramic heater, but it is also possible to use mullite, alumina, sialon, silicon nitride, or the like. These materials are preferable because they have relatively low thermal conductivity and can reduce the amount of heat transferred from the ceramics to the reaction vessel.

From the above, aluminum nitride is particularly preferable as the material of the ceramic heater, and the material of the fixed cylindrical body and / or the fixed support attached to the ceramic heater is matching of the coefficient of thermal expansion with aluminum nitride, and furthermore, heat conduction. Mullite or a mullite-alumina composite is particularly preferred due to its low rate. In addition, as a material of the reaction vessel for this combination, aluminum or an aluminum alloy is particularly preferable from the viewpoint of matching of thermal expansion coefficients. In an actual device, a corrosive gas may be used in some cases, and it is needless to say that it is important to select a material according to the use.

In addition, by using the wafer holder in the present invention, a fixed cylindrical body containing the electrode terminals and leads of the ceramic heater and further the temperature measuring element, a fixed cylindrical body simply supporting the ceramic heater, and / or Alternatively, a highly reliable semiconductor manufacturing apparatus without damage to the fixed support can be provided. In particular, among various semiconductor manufacturing apparatuses, the present invention is particularly suitable as an apparatus for firing a low-k film, which has less restrictions on a material that can be inserted into a reaction vessel.

Example 1
A predetermined amount of a sintering aid was added to the ceramic powders shown in Table 1 below, and a solvent and the like were further added, followed by ball mill mixing to prepare a slurry. The slurry was spray-dried to produce granules, and the obtained granules were press-molded using a predetermined mold. After degreased the obtained molded body, each was sintered at a predetermined temperature to obtain a ceramic sintered body. The thermal expansion coefficient and the thermal conductivity of each of the obtained ceramic sintered bodies were measured and shown in Table 1.

抵抗 A resistance heating element circuit was formed on each substrate made of the ceramic sintered body by a method such as screen printing, and an RF electrode and an electrostatic chuck electrode were formed as necessary. This was fired under predetermined conditions, and a ceramic plate was bonded thereon to protect the resistance heating element, the RF electrode, and the electrostatic chuck electrode as necessary. For the obtained ceramic heater, a wafer pocket for mounting a wafer was formed by machining, and electrode terminals and leads for connecting to each electric circuit were attached.

A fixed cylindrical body and / or a fixed support made of the material shown in Table 2 below was attached and fixed to the surface (rear surface) opposite to the wafer heating surface of each ceramic heater. Examples of the fixing method include joining with glass shown in FIGS. 2-1 and 2-2, joining with a brazing material using active metal brazing shown in FIGS. 3-1 and 3-2, and FIGS. 2, fitting into the counterbore part on the back surface of the ceramic heater shown in FIGS. 5-1 and 5-1, or an integral type of the ceramic heater and the cylindrical body shown in FIGS. 6-1 and 6-2. Either was used. Note that all the cylindrical bodies used had an outer diameter of 10 mm and an inner diameter of 6 mm. All the supports were solid pillars having an outer diameter of 10 mm. Fig. 5-
1 and FIG. 5-2, the counterbore depth is 3 mm and the diameter is 10.1 mm.
And While the electrode terminal and the lead were accommodated in the tubular body, only the thermocouple was housed in the metallic tubular body.

At this time, when the parallelism of each of the cylindrical body and / or the support attached to the ceramic heater was measured, they were all within 0.1 mm. The surface roughness near the O-ring contact surface of the attached cylindrical body and / or the support was Ra ≦ 0.3 μm, and as a result of observing the surface with an optical microscope, the surface roughness exceeded 0.05 mm. It was confirmed that there were no defects.

に 対 し て A reaction vessel having a predetermined shape made of a material shown in Table 3 below was prepared for the wafer holder thus manufactured. The wafer holder was mounted in the reaction vessel, and the space between the tubular body and / or the columnar body and the reaction vessel was hermetically sealed with a rubber O-ring. At this time, the parallelism between the wafer mounting surface of the ceramic heater and the reaction vessel was 0.15 mm or less. Thereafter, the temperature was raised to a predetermined temperature by supplying power to the ceramic heater, the temperatures of the ceramic heater and the reaction vessel were measured with a thermocouple, and the uniformity of the ceramic heater was determined. Thereafter, the temperature was lowered to room temperature, and the state of breakage of the fixed cylindrical body and / or the fixed support was confirmed.

The obtained results are shown in Tables 4 to 45 below, which are divided into test conditions and test results for each material of the ceramic heater and the fixed cylindrical body and / or the fixed support. The atmosphere in the reaction vessel when the ceramic heater was heated was vacuum. The thermal uniformity of the ceramic heater was measured using a wafer thermometer. Regarding the airtightness between the cylindrical body and / or the columnar body and the reaction vessel, those having a leak rate of 10 ⁻⁹ Pam ³ / s or less at high temperature are those of ◎ and those of 10 ⁻⁷ Pam ₃ / s or less. Is indicated as 〇.

Example 2
The sample 3-1 wafer holder used in Example 1 was prepared. A stainless steel reflecting plate was attached to this, the temperature of the ceramic heater was raised to 500 ° C., and the power consumption was measured. A hole having a diameter of 12 mm is formed in the reflector so that the cylindrical body and / or the support can penetrate. Further, the power consumption was measured while changing the mounting distance between the reflector and the ceramic heater. At this time, the stainless plate had a thickness of 0.5 mm, a diameter of 330 mm, and a surface roughness Ra of 0.05 μm. The results are shown in Table 46 below.

Further, the power consumption of the reflector having the surface roughness changed while fixing the position of the reflector at 15 mm from the ceramic heater was measured. Table 47 shows the obtained results. From these results, it is understood that power consumption can be reduced by using a reflector having a surface roughness of 1.0 μm or less in Ra and further 0.1 μm or less and installing the reflector near the ceramic heater.

Example 3
The mullite cylindrical body and one end of the support were attached to the aluminum nitride heater used in Example 1 in the same manner as in Example 1 by attaching a glass. At this time, the parallelism was changed by polishing the end faces of the cylindrical body and the support body at the joining surface of the ceramic heater and changing the mounting angle to the ceramic heater. The other end side of the cylindrical body and the support was further attached to a reaction vessel made of aluminum, the inside of the reaction vessel was evacuated, and the helium leak rate was measured. The results are shown in Table 48 below. The surface roughness in the vicinity of the O-ring contact surface of the mullite cylindrical body and the support used at this time was Ra ≦ 0.3 μm, and the surface was observed with an optical microscope. It was confirmed that there was no defect exceeding .05 mm.

Example 4
Next, with respect to a plurality of mullite cylindrical bodies, the surface roughness near the O-ring contact surface when mounted on the reaction vessel was changed, and one end was attached to the ceramics heater by glass in the same manner as in Example 1. After the other end was attached to the reaction vessel, the inside of the reaction vessel was evacuated and the helium leak rate of the sealed portion was measured. The results are shown in Table 49 below.

Example 5
For the aluminum nitride heater used in Example 1, the same mullite cylindrical body as in Example 1 was prepared. Among these mullite cylindrical bodies, those having defects having different sizes in the vicinity of the O-ring contact surface were selected, and those having no defects were each glass-coated on an aluminum nitride heater. Then, the other end side of the cylindrical body was attached to the reaction vessel, and after evacuation, the helium leak rate of the O-ring contact surface was measured. The results are shown in Table 50 below.

Example 6
A mullite cylindrical body and a support were attached to the aluminum nitride heater used in Example 1 in the same manner as in Example 1 by attaching a glass. At this time, the parallelism between the ceramic heater and the reaction vessel was changed by polishing the end surfaces of the cylindrical body and the support body at the joining surface of the ceramic heater and changing the mounting angle to the ceramic heater. These ceramic heaters were attached to an aluminum reaction vessel, the inside of the reaction vessel was evacuated, and a wafer desorption test was performed. The results are shown in Table 51 below.

Example 7
In order to compare the corrosion resistance of the ceramic heater, the surface of each ceramic sintered body shown in Table 1 was polished. The practicality of each processed sintered body sample was confirmed in the following manner.

First, a disk-shaped heater in which a separately prepared aluminum nitride-based ceramic was used as a matrix and W filaments were embedded therein was prepared. Next, each sintered body sample shown in Table 1 was placed on this heater, and was placed in a vacuum chamber of a plasma generator using a high frequency of 13.56 MHz. Each of these sintered body samples was treated for 5 hours in an environment of a heating temperature of 100 ° C. and a plasma density of CF ₄ gas of 1.4 W / cm ² . Thereafter, the density of the etching craters on the plasma irradiation surface (when observed using a scanning electron microscope, the number of craters having a maximum diameter of 1 μm or more within an arbitrary visual field of 1000 μm ^{2 on} the surface) was confirmed. The results are shown in Table 52.

From the above results, it can be seen that aluminum nitride is superior in terms of corrosion resistance, and that the amount of the sintering aid is preferably 0.05% by weight or more and 1.0% by weight or less.

Example 8
Each of the wafer holders in which good results were obtained in Example 1 was incorporated into a semiconductor manufacturing apparatus and subjected to plasma CVD, low pressure CVD, low-k film firing, plasma etching, and insulating film CVD. As a result, no damage occurred to the fixed cylindrical body or the fixed support during the processing of the wafer. In particular, in the case of firing a Low-k film, a particularly uniform film quality was obtained.

Example 9
Next, various structural examples according to the present invention will be described. These structures can be variously selected according to each use and the shape of the reaction vessel. For example, as shown in FIG. 7A, the support 5b is installed near the center of the reaction vessel 4. When the support 5b is not fixed to the reaction vessel 4 at this time, the support 5b may or may not be joined to the ceramic heater 2. Conversely, it is also possible to adopt a structure in which the support 5b is fixed to the reaction vessel 4 side by brazing or the like, but not fixed to the ceramic heater 2 side. Further, as shown in FIG. 7-1 and FIG. 7-2, a plurality of cylindrical bodies 5c and a support body 5b are provided to support the ceramic heater. At this time, when the tubular body 5c and the support 5b are not fixed to the reaction vessel 4, the tubular body 5c and the support 5b may or may not be joined to the ceramic heater 2. Conversely, it is also possible to adopt a structure in which the cylindrical body 5c and the support 5b are fixed to the reaction vessel 4 side by brazing or the like, but not fixed to the ceramic heater 2 side. In the case where the cylindrical body 5c and the support 5b are not fixed to the ceramic heater, the cylindrical body 5c and the support 5b do not need to satisfy the relational expression according to the present invention. can do.

FIG. 2 is a schematic cross-sectional view showing a specific example of a wafer holder according to the present invention, showing a state where the wafer holder is installed in a reaction vessel. It is another specific example of the wafer holder concerning this invention, Comprising: It is a schematic sectional drawing which shows the state installed in the reaction container. It is a schematic sectional view showing a ceramic heater concerning the present invention, and a fixing method of glass with a cylindrical object. FIG. 4 is a schematic cross-sectional view illustrating a method for fixing the ceramic heater and the support with glass according to the present invention. It is an outline sectional view showing the ceramic heater concerning the present invention, and the fixing method of the cylindrical body with the brazing material. FIG. 4 is a schematic cross-sectional view showing a method for fixing a ceramic heater and a support with a brazing material according to the present invention. FIG. 4 is a schematic cross-sectional view illustrating a method for fixing the ceramic heater and the cylindrical body by screwing according to the present invention. FIG. 3 is a schematic cross-sectional view showing a method for fixing the ceramic heater and the support by screwing according to the present invention. It is an outline sectional view showing a fixing method by fitting of a ceramic heater and a cylindrical body concerning the present invention. FIG. 4 is a schematic cross-sectional view showing a method for fixing the ceramic heater and the support according to the present invention by fitting. It is an outline sectional view showing a fixing method by unification of a ceramic heater and a cylindrical body concerning the present invention. FIG. 4 is a schematic cross-sectional view showing a fixing method by integrating a ceramic heater and a support according to the present invention. It is an example of the wafer holder provided with the some cylindrical body and the support body, Comprising: It is a schematic sectional drawing which shows the state installed in the reaction container. It is another example of the wafer holder provided with the some cylindrical body and the support body, Comprising: It is a schematic sectional drawing which shows the state installed in the reaction container.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Wafer holding body 2 Ceramic heater 3 Resistance heating element 4 Reaction vessel 5 Fixed cylindrical body 5a Fixed support 5b Support 5c cylindrical body 6 O-ring 7 Lead 8 Temperature measuring element 10 Glass 11 Brazing material 12 Screwing 13 Counterbore Department

Claims (23)

A wafer holder for holding and processing a semiconductor wafer on a ceramic heater supported by a cylindrical body in a reaction vessel, wherein at least two of the cylindrical bodies have one end connected to the ceramic heater and the other end. Side is a fixed cylindrical body fixed to the reaction vessel,
The maximum temperature reached by the ceramic heater is T1,
The coefficient of thermal expansion of the ceramic heater is α1,
The maximum temperature of the reaction vessel is T2,
The thermal expansion coefficient of the reaction vessel is α2,
The longest distance on the ceramic heater at room temperature between the fixed cylindrical bodies is L1,
When the longest distance on the reaction vessel at normal temperature between the fixed cylindrical bodies is L2,
| (T1 × α1 × L1) − (T2 × α2 × L2) | ≦ 0.7 mm
A wafer holder that satisfies the following relational expression: A wafer holder for holding and processing a semiconductor wafer on a ceramic heater supported by a cylindrical body and / or a support in a reaction vessel, wherein at least two of the cylindrical body and / or the support are used. One is a fixed cylindrical body and / or a fixed support having one end fixed to the ceramic heater and the other end fixed to the reaction vessel,
The maximum temperature reached by the ceramic heater is T1,
The coefficient of thermal expansion of the ceramic heater is α1,
The maximum temperature of the reaction vessel is T2,
The thermal expansion coefficient of the reaction vessel is α2,
The longest distance on the ceramic heater at room temperature between the fixed cylindrical body and / or the fixed support is L1,
When the longest distance on the reaction vessel at normal temperature between the fixed cylindrical body and / or the fixed support is L2,
| (T1 × α1 × L1) − (T2 × α2 × L2) | ≦ 0.7 mm
A wafer holder that satisfies the following relational expression: The relational expression is: | (T1 × α1 × L1) − (T2 × α2 × L2) | ≦ 0.3 mm
The wafer holder according to claim 1, wherein: The thermal expansion coefficient of the ceramic heater is 8.0 × 10 ⁻⁶ / K or less, and the thermal expansion coefficient of the reaction vessel is 15 × 10 ⁻⁶ K or more. Or a wafer holder. The wafer according to claim 4, wherein the ceramic heater has a coefficient of thermal expansion of 6.0 × 10 ⁻⁶ / K or less, and the reaction vessel has a coefficient of thermal expansion of 20 × 10 ⁻⁶ K or more. Holding body. The wafer holder according to any one of claims 1 to 5, wherein the length of the fixed cylindrical body and / or the fixed support from the ceramic heater to the reaction vessel is 320 mm or less. The length of the fixed tubular body and / or the fixed support from the ceramic heater to the reaction vessel is 150 mm or less, and the thermal conductivity of the fixed tubular body and / or the fixed support is 30 W / mK or less. The wafer holder according to any one of claims 1 to 4, wherein: The wafer holder according to any one of claims 1 to 5, wherein the reaction vessel is not water-cooled. The wafer holder according to any one of claims 1 to 8, further comprising a reflector between the reaction vessel and the ceramic heater for reflecting heat of the ceramic heater. 10. The parallelism of each of the fixed cylindrical body and / or the fixed support having both ends fixed to the reaction vessel side and the ceramic heater side is within 1.0 mm, respectively. Or a wafer holder. The wafer holder according to claim 10, wherein the parallelism of each of the fixed cylindrical body and / or the fixed support is within 0.3 mm. An O-ring fixed to the reaction vessel and keeping the airtight from the outside of the reaction vessel is provided, and the surface roughness of the cylindrical body and / or the support near the contact surface with the O-ring is 5. The wafer holder according to claim 1, wherein the thickness is 0 μm or less. 13. The wafer holder according to claim 12, wherein the surface roughness of the cylindrical body and / or the support near the contact surface with the O-ring is not more than 1.0 [mu] m in Ra. 14. The wafer holder according to claim 13, wherein the surface roughness of the cylindrical body and / or the support near the contact surface with the O-ring is 0.3 μm or less in Ra. An O-ring that is fixed to the reaction vessel and keeps airtight from the outside of the reaction vessel; and the size of a surface defect existing near the contact surface of the tubular body and / or the support with the O-ring is reduced. The wafer holder according to any one of claims 1 to 14, wherein the diameter of the wafer holder is 1 mm or less. The wafer holder according to claim 15, wherein a size of a surface defect existing near a contact surface of the cylindrical body and / or the support with the O-ring is 0.3 mm or less in diameter. . 17. The wafer holder according to claim 16, wherein a size of a surface defect existing near a contact surface of the cylindrical body and / or the support with the O-ring is 0.05 mm or less in diameter. . The wafer holder according to any one of claims 1 to 17, wherein the parallelism between the ceramic heater and the bottom of the reaction vessel is within 1.0 mm. 19. The wafer holder according to claim 18, wherein the parallelism between the ceramic heater and the bottom of the reaction vessel is within 0.2 mm. 20. The wafer holder according to claim 1, wherein a main component of the ceramic heater is one of alumina, silicon nitride, aluminum nitride, and silicon carbide. The main component of the ceramic heater is aluminum nitride, the main component of the reaction vessel is aluminum or an aluminum alloy, and the main component of the fixed cylindrical body and / or the fixed support is mullite or a mullite-alumina composite. The wafer holder according to any one of claims 1 to 20, wherein A semiconductor manufacturing apparatus comprising the wafer holder according to any one of claims 1 to 21 mounted thereon. 23. The semiconductor manufacturing apparatus according to claim 22, wherein the apparatus is used for firing a Low-k film.

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