JP2000173923A - Heater with wafer holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater with a wafer holder attached which can be suitably used for heat treatment of a wafer, etc., in a semiconductor manufacturing process and which can suppress scattering of dust, etc., and which can facilitete mounting and taking-out of a wafer and which has a good soaking property and can be manufactured easily. SOLUTION: A heater 1 with a wafer holder attached is provided with a heating element 4 stored in a quartz glass material 2, a heated surface formed on an upper face of the quartz glass material, a wafer holder 5 which is projecting from the heated surface as an integral part of the glass material to support a lower face of a peripheral part of a wafer, and a space 6 formed between a lower face of a wafer and the heated surface when a wafer is mounted on the wafer holder. The heating element 4 is formed from a carbon wire which is made by uniting a plurality of carbon fibers of 5-15 μm in diameter into one and weaving several bundles of carbon fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heater with a wafer holder, and more particularly, to a heater with a wafer holder in which a wafer holder is integrally formed above a heating surface of a quartz glass body in which a heating element is embedded. .

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, various heat treatments are applied to a single crystal silicon wafer or the like. For example, when performing the surface heat treatment of this wafer, on a mounting table in a processing vessel configured to be airtight and capable of reducing pressure,
After a wafer to be processed is placed and the atmosphere in the container is replaced with a processing gas, predetermined processing is performed. In this case, the wafer to be processed is heated to a predetermined temperature, and this heat treatment requires strict temperature control, and more rapid control of temperature rise / fall and a heat treatment atmosphere in which no particles such as dust are present. It is required to maintain a good atmosphere. As a means of heating the semiconductor wafer in response to this demand, a method in which a heating element such as platinum or nickel is arranged in a predetermined manner inside a quartz glass plate provided with a concave portion for mounting a wafer on the upper surface. Conventionally known.

[0003]

However, when the heating surface of the wafer is a concave portion which is in contact with the entire surface of the lower surface of the wafer, it is not easy to form the heating surface flat so that the heating is uniform over the entire surface of the wafer. . Conversely, if the bottom surface of the concave portion is finished with high precision by mirror finishing or the like, there is a technical problem that the bottom surface of the concave portion comes into close contact with the wafer after heat treatment, and it is not easy to remove the wafer from the concave portion. In an extreme case, the wafer may be damaged or distorted at the time of unloading.

Further, in the above-mentioned means, since the heating material has a planar shape simply formed by pattern printing, the temperature is highest immediately above the location where the heating element is arranged. Lower than. Therefore,
When the wafer is brought into direct contact with the heating surface, there is a technical problem that the wafer is easily affected by uneven temperature distribution on the heating surface.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problems, and suppresses the emission of dust and the like which are preferably used for heat treatment of a wafer or the like in a semiconductor manufacturing process. An object of the present invention is to provide a heater with a wafer holder which can be easily taken out and is easily manufactured.

[0006]

According to the present invention, a heater with a wafer holder according to the present invention comprises a heating element housed in a quartz glass body, a heating surface formed on an upper surface of the quartz glass body, and a heating surface. A protruding and integrally provided wafer holder for supporting a lower surface of a peripheral portion of the wafer; and a gap formed between the lower surface of the wafer and the heating surface when the wafer is placed on the wafer holder. It is characterized by.

As described above, since the wafer holder is provided integrally with the quartz glass body containing the heating element, a heater with a wafer holder can be easily formed. Further, since a gap is formed between the lower surface of the wafer and the heating surface, the wafer is not affected by a non-uniform temperature distribution on the heating surface, as compared with a case where the wafer is directly contacted with the heating surface. It can be heated uniformly. That is, the radiant heat rays emitted from the heating surface are sufficiently scattered in the gaps, and the scattered heat rays hit the wafer surface evenly, so that superior soaking properties can be achieved in each stage as compared with the conventional heating apparatus.

Furthermore, since a gap is formed between the lower surface of the wafer and the heating surface, the wafer does not come into close contact with the heating surface, and the wafer can be easily taken out. Furthermore, since a transfer means such as a fork for transferring the wafer can be inserted into the gap, the wafer can be easily mounted on and removed from the wafer holder.

The heater with a wafer holder according to the present invention includes a first heating element housed inside a quartz glass body, a first heating surface formed on an upper surface of the quartz glass body, 1, protruding from the heating surface and integrally provided,
A first holder that supports a lower surface of a peripheral portion of the wafer and a first gap formed between the lower surface of the wafer and the first heating surface when the wafer is placed on the wafer holder; A wafer is placed on a heater section, a second heating element housed inside the quartz glass body, a second heating surface formed on the lower surface of the quartz glass body, and a wafer holder of the first heater section. A second heater section having a second gap formed between the upper surface of the wafer and the second heating surface when the wafer is placed.

As described above, in addition to the above-described gap, the second heater portion is provided, so that the wafer can be more uniformly heated in the vertical direction. Further, since a gap is formed between the lower surface of the wafer and the heating surface, the wafer does not come into close contact with the heating surface, and the wafer can be easily taken out. Furthermore, since a transfer means such as a fork for transferring a wafer can be inserted into the gap, the wafer can be easily mounted and removed from the wafer holder.

Here, it is desirable that the first heater section and the second heater section are formed integrally. Also,
The gap formed between the lower surface of the wafer and the heating surface is desirably in the range of 0.5 to 10 mm, and the gap formed between the upper surface of the wafer and the heating surface is 0.1 mm. It is desirable to be in the range of 5 to 10 mm.
If the gap is less than 0.5 mm, the heating surface may be affected by uneven temperature distribution, and it is not possible to insert a transfer means such as a fork for transferring a wafer. On the other hand, if the gap exceeds 10 mm, heat from the heating surface cannot be effectively transmitted to the wafer.

Further, it is preferable that a soaking plate is provided between the lower surface of the wafer and the heating surface, and a soaking plate is provided between the upper surface of the wafer and the heating surface. Is desirable. Thus, by providing the heat equalizing plate, the wafer can be more uniformly heated. The heat equalizing plate is desirably formed of any one of a silicon carbide material, a carbon material, a silicon carbide-coated carbon material, a silicon carbide-coated silicon carbide material, and a single crystal silicon material. Also,
In order to insert a transfer means such as a fork for transferring a wafer into the gap, it is preferable that a cutout communicating with the gap is formed in the wafer holder.

Further, the quartz glass body containing the heating element forms a continuous groove of a predetermined pattern on the surface of one quartz glass plate, and the groove has a diameter of 5 to 15 μm.
It is preferable that a wire heating element formed by knitting a plurality of fiber bundles obtained by bundling carbon fibers is arranged, and further fused with another quartz glass plate on this surface, and the carbon wire It is desirable that the heating element is made of a carbon fiber material having an impurity content of 10 ppm or less based on ash.

Since the conventional heating element is formed by directly printing a heating element such as platinum or nickel on quartz glass, the heating element may be damaged or damaged due to a difference in thermal expansion coefficient between the heating element and quartz glass. In some cases, strong local internal distortion was caused even if the temperature did not reach, and local temperature unevenness sometimes occurred during heat generation. In addition, under high temperature, it may come into contact with the quartz glass containing the heating element and react to deteriorate.

On the other hand, a groove is formed in at least one quartz glass plate, and a plurality of carbon fiber bundles each having a diameter of 5 to 15 μm are bundled in the groove to form a wire shape or the like. Knit into a vertically long shape like a tape shape, and reduce the content of impurities to 10p with ash
pm or less, the carbon-based heating element has a large diameter of 5 to 5 on the surface of the wire-shaped or tape-shaped heating element.
Since the 15 μm carbon fiber has a structure in contact with the sealed member made of quartz glass, even if the heating element is energized to generate heat at a high temperature, the reaction between carbon and quartz glass proceeds, resulting in carbon. It is possible to prevent the quality heating element from deteriorating. (Since the fluffy carbon fiber on the surface of the heating element comes into contact with the sealed member made of quartz glass, silicification proceeds from the contacted part. However, since the diameter is extremely small and the volume is small, this silicidation reaction occurs. It is presumed that it suppresses the progress of the entire heating element.)

That is, this means that heat generation unevenness can be prevented, and the service life can be extended. As a result, local temperature unevenness can be suppressed as much as possible, and even if it comes into contact with quartz glass, it is less likely to react and deteriorate, so that it is excellent in durability.

Here, the reason why the diameter of each of the plurality of bundled carbon fibers is set to 5 to 15 μm is that, when the diameter is less than 5 μm, each fiber is weak, and the heater member is formed by bundling and knitting the fibers into a predetermined vertically long shape. It will be difficult to do. Further, since the fibers are thin, the number of fibers for obtaining a predetermined resistance value increases, which is not practical. Also,
If the thickness exceeds 15 μm, not only is it difficult to knit a plurality of bundled carbon fiber bundles because of poor flexibility, but also there is a problem that the carbon fiber is cut and the strength is significantly reduced. Further, when the wire heating element is made of a carbon fiber material having an impurity content of 10 ppm or less on an ash basis, local abnormal heat generation of the wire heating element can be suppressed, and the wire heating element can be suitably used for heat treatment of a wafer or the like. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. 1 and 2 are views showing one embodiment of a heater with a wafer holder according to the present invention. FIG. 1 is a plan view, and FIG. 2 is a sectional view taken along line XX of FIG. FIG. 3 is a diagram showing a pattern of a carbon wire heating element 4 provided in the heater with a wafer holder in FIGS. As shown in FIGS. 1 and 2, a heater 1 with a wafer holder according to the present invention comprises a quartz glass body 2 as a whole, and the upper surface of the quartz glass body 2 has a circular flat surface corresponding to the wafer surface as a heating surface 2a. Is formed.

A so-called zigzag pattern hollow hole 3 shown in FIGS. 2 and 3 is formed at a predetermined depth below the heating surface 2a (inside the quartz glass body 2), and a carbon wire heating element 4 is accommodated therein. Have been. In addition, a wafer holder 5 for supporting the peripheral portion of the wafer A to be processed is provided integrally with the heating surface 2a so as to protrude from the heating surface 2a. There is a predetermined gap 6 between the lower surface of the wafer A mounted on the wafer holder 5 and the heating surface 2a.

Further, as shown in FIG. 1, the heating surface 2a
The wafer holder 5 is provided with two notches B communicating with the gap so that a fork can be inserted into the gap 6 from the side surface of the heater 1. The gap 6 between the heating surface 2a and the lower surface of the wafer A to be placed is preferably in the range of 0.5 to 10 mm. This is preferable from the viewpoint of convenience of inserting a fork at the time.

As the carbon wire heating element 4 used in the heater 1 with a wafer holder according to the present invention, a carbon fiber heating element which is obtained by weaving a plurality of carbon fiber bundles into a wire shape using a plurality of fiber bundles is used. In the case of the heater with a wafer holder shown in FIG.
Is disposed at a predetermined depth below the heating surface 2a in the quartz glass body, as shown in FIG. 3, in a hollow hole 3 whose outer shell is formed in a circular zigzag line shape. The planar arrangement pattern of the hollow holes 3 in which the carbon wire heating elements 4 are accommodated is, for example, the zigzag line shape shown in FIG.
The shape may be a spiral shape or another shape as shown in FIG. The depth at which the hollow hole 3 is formed is usually a depth of about 1 to 5 mm from the heating surface 2a from the viewpoint of the temperature rise / fall response of the heater, the ceiling strength of the hollow hole 3, and the production of the quartz glass body. Is determined.

As a specific example of the carbon wire heating element 4, a carbon fiber having a diameter of 5 to 15 μm (for example, a carbon fiber having a diameter of about 7 μm) is used for about 300 μm.
A fiber bundle having about 2 to 350 fibers bundled into a wire shape having a diameter of about 2 mm using about 9 bundles can be given. In the above case, the braided span of the wire is about 2 to 5 mm, and the surface fuzzing by the carbon fiber is about 0.5 to 2.5 mm.

In the present invention, it is preferable that the carbon wire heating element 4 has the above-mentioned surface fuzz made of carbon fiber single fiber.
Has the effect of directly contacting the quartz glass wall surface of the hollow hole 3 that accommodates the quartz glass and suppressing deterioration due to a contact reaction with quartz glass (SiO ₂ ) under high-temperature heat generation. That is, on the outer peripheral surface of the carbon wire of the carbon wire heating element 4, FIG.
As shown by reference numeral 4a of FIG. The fluff 4a is obtained by cutting a carbon wire and protruding from the outer peripheral surface. The body of the body 4 is not in contact. Therefore, the reaction between the quartz glass (SiO ₂ ) and the carbon (C) of the carbon wire heating element 4 at a high temperature as described above is suppressed as much as possible, and the deterioration of the quartz glass and the decrease in the durability of the carbon wire are suppressed. .

In the heater with a wafer holder of the present invention, a plurality of such carbon wire heating elements may be used, and in this case, the quality relating to the heating characteristics can be stabilized. From the viewpoints of homogeneity of heat generation properties, durability stability and the like and avoidance of dust generation, the carbon fiber is preferably of high purity, and particularly, the amount of impurities contained in the carbon fiber is 1% by weight of ash.
0 ppm or less, more preferably 3 ppm or less.
ppm or less.

The heating element is formed by bundling 100 to 800 carbon fibers having a size of 5 to 15 μm.
It is preferable to bundle more than six, preferably six to twelve, and knit them into a vertically long shape such as a wire shape or a tape shape. 100 carbon fiber bundles
If the number is less than 6 books, 6 to 12 bundles are not enough to obtain a predetermined strength and resistance value, and it is difficult to knit. Further, since the number is small, the braid is loosened with respect to the partial breakage, and it is difficult to maintain the shape. On the other hand, if the number exceeds 800, the number of bundles for obtaining a predetermined resistance value decreases, and it becomes difficult to maintain the wire shape by braiding.

Further, the heating element preferably has a resistance value at 1000 ° C. of 1 to 20 Ω / m. The reason is that in a general semiconductor manufacturing equipment heating device,
This is because it is necessary to match with the conventional transformer capacity. That is, when the resistance value exceeds 20 Ω / m · line, the resistance is so large that the length of the heater cannot be increased, and heat is lost between the terminals, so that temperature unevenness tends to occur. On the other hand, when the resistance value is less than 1 Ω / m · line, on the other hand, the resistance is low, so that the heater length must be longer than necessary, and the unevenness of the structure of the elongated heater member such as carbon wire or carbon tape. There is a greater possibility that the temperature will vary due to the temperature and unevenness of the atmosphere. The electric resistance of the heating element at 1000 ° C. is more preferably 2 to 10 Ω / m · line in order to obtain the above characteristics with higher reliability.

The shape of the convex wafer holder 5 formed on the heating surface 2a of the heater with a wafer holder according to the present invention is as follows. The lower surface of the wafer other than the abutment portion 5 may be formed so as to face the heating surface 2a with a gap 6 therebetween, and may be formed in such a shape that a fork can be inserted from the side. It is not limited.

FIGS. 5 (a), 5 (b) and 5 (b) show other shapes of the wafer holder 5 in addition to those shown in FIGS.
A wafer holder having the shape shown in (c) can be exemplified. That is, FIG. 5A shows one cutout portion B, FIG. 5B shows four cutout portions B, and FIG. Shape and
Three are provided on the heating surface.

Instead of directly loading and unloading the wafer from the side using the above-described fork, the wafer is pushed up from below by means of a push-up pin and then loaded and unloaded onto the fork. In such a case, the wafer holder can be used in a ring shape without a notch. In this case, a plurality of holes penetrating in the thickness direction may be provided at positions inside the ring-shaped wafer holder of the heater with the present wafer holder so that the push-up pins can be moved.

In the heater with a wafer holder according to the present invention, for example, as shown in FIG. 7, the heat equalizing plate 7 is provided below the wafer A to be mounted and above the heating surface 2a. Is more preferable from the viewpoint of uniformity of heat throughout the plane of the wafer. The gap between the lower surface of the wafer A and the heating surface 2a is divided into two gaps by the heat equalizing plate 7. The height of each gap is appropriately set in consideration of the heat uniformity and the space for inserting the transfer means, and is preferably about 0.5 mm to 5 mm. The shape and thickness of the heat equalizing plate 7 are appropriately set in consideration of various conditions such as the shape of the wafer holder 5 and the heat treatment temperature, but usually, a silicon carbide material or a carbon material having a thickness of about 0.3 to 2 mm is used. A plate made of a material such as silicon carbide-coated carbon material, silicon carbide-coated silicon carbide material, or single-crystal silicon material is used.

Further, the heater 1 with a wafer holder according to the present invention
For example, as shown in FIG. 8, a second heater unit 31 containing the above-described carbon wire heating element 41 in quartz glass may be integrally provided on the upper surface side of the wafer A to be processed. good. This type of heater with a wafer holder can heat the wafer from both the upper and lower surfaces, so that the heater can be more excellent in uniform heating. Of course, in the heater with the wafer holder of this embodiment, the soaking plates 7, 71 and the like can be provided in the upper and lower heating units, respectively.

Further, as shown in FIG. 9, an opaque (or foamed) quartz glass layer 10c having a large number of closed pores may be provided on the opposite side (lower side) of the heating surface 2a. The transmission of radiant heat to the lower portion of the heater is suppressed by the quartz glass layer 2d. For the same purpose,
For example, as shown in FIG. 10, the reflection plate 8 may be embedded in quartz glass below the heater surface.

A method for manufacturing a heater with a wafer holder according to the present invention will be described with reference to FIG. First, a plate-like quartz glass member (main member) 2c having a groove for accommodating the carbon wire heating element 4 formed on the upper surface thereof and a wafer holder 5 formed on the upper surface side, and the lower surface side sealing the groove from above. A quartz glass plate member (cover member) 2c serving as a slip cover surface is prepared, the heating element 4 is disposed in the groove, and assembled as shown in FIG. Then, after the inside of the groove is made to be a non-oxidizing atmosphere, the heater 1 with the holder in which the carbon wire heating element 4 is accommodated in the hollow hole 3 is manufactured by fusing and integrating at the joint surface of both members.

In this method, in particular, the main member 2c
Is used as a quartz glass material having a melting and softening temperature, that is, a high-viscosity quartz glass having a viscosity at 1430 ° C. of 3.0 × 10 ¹⁰ poise or more. However, it is preferable to use a low-viscosity quartz glass having a viscosity of 0.05 to 0.85 times the viscosity of the main member 2c. That is, the main member 2c
The high-viscosity quartz glass provides stable shape retention at high temperatures (heat-resistant deformation at a predetermined temperature), and the low-viscosity quartz glass of the lid member 2b is favorably applied to the main member glass during fusion. It is fused.

In the heater 1 with a wafer holder according to the present invention thus configured, the temperature distribution state during the heat treatment is as follows.
For example, the temperature of the carbon wire heating element 4 is 1350 ° C.
In this case, the temperature distribution within the wafer surface excluding the contact portion with the wafer holder 5 is within about 1250 ± 5 ° C., and the contact portion with the wafer holder 5 is about 1255 ° C., which indicates that the heat uniformity is excellent. confirmed.

[0036]

According to the heater with a wafer holder of the present invention, the radiant heat generated from the heating surface is provided because the wafer holder is provided on the heating surface and a gap exists between the wafer to be mounted and the heating surface. The lines are sufficiently scattered in the gaps, and the scattered heat lines uniformly heat the wafer surface, so that each stage has superior heating uniformity as compared with a conventional heating device. Further, since a part of the wafer holder is cut out, a wafer transfer means such as a fork can be inserted from a side into a gap between the heating surface and the lower surface of the wafer.
Loading and unloading of the wafer to and from the holder is easy, and damage and distortion of the wafer during loading and unloading can be prevented.

Further, since a carbon wire formed by knitting a plurality of fiber bundles obtained by bundling carbon fibers is used as a heating element, local temperature unevenness can be suppressed as much as possible. However, since they are less likely to react and deteriorate, they have excellent durability.
In addition, the heating element has an impurity content of 10 pp on an ash basis.
When the carbon fiber material is not more than m, it is possible to suppress local abnormal heat generation of the carbon wire heating element, and it can be suitably used for heat treatment of a wafer or the like.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a heater with a wafer holder of the present invention.

FIG. 2 is a sectional view of the heater of FIG. 1 taken along line XX.

FIG. 3 is a diagram showing a plane pattern of a hollow hole for accommodating a carbon wire heating element provided in the heater of FIG. 1;

FIG. 4 is a diagram showing a planar pattern of another form of a hollow hole for accommodating a carbon wire heating element.

FIG. 5 is a diagram showing an example of a shape of a wafer holder of the heater according to the present invention.

FIG. 6 is a sectional view showing a fused state of the quartz glass body of the present invention.

FIG. 7 is a cross-sectional view showing another embodiment of the heater of the present invention.

FIG. 8 is a sectional view showing another embodiment of the heater of the present invention.

FIG. 9 is a cross-sectional view showing another embodiment of the heater of the present invention.

FIG. 10 is a cross-sectional view showing another embodiment of the heater of the present invention.

FIG. 11 is a diagram showing a carbon wire heating element.

[Explanation of symbols]

 Reference Signs List 1 heater with wafer holder 2 quartz glass body 2a heating surface 2b lid member 2c main member 2d opaque (foamed) quartz glass member 3, 31 hollow hole 4, 41 carbon wire heating element 4a fuzzing 5 wafer holder 6, 6a, 6b gap 7 , 71 Heat equalizer 8 Reflector A Wafer B Notch

Continued on the front page (72) Inventor Tomio Kane 378 Oguni-machi, Oguni-machi, Nishiokitama-gun, Yamagata Prefecture Inside the Oguni Plant of Toshiba Ceramics Co., Ltd. (72) Inventor Norihiko Saito No. 378, Oguni-machi, Oguni-machi, Nishiokitama-gun, Yamagata Prefecture Toshiba Ceramics Co., Ltd. (72) Inventor Jun Sekoku 378, Oguni-machi, Ogunimachi, Nishiokitama-gun, Yamagata (72) Inventor Hideyuki Yokoyama 378 Oguni-machi, Oguni-machi, Oguni-machi, Nishiokitama-gun, Yamagata Prefecture Inside the Oguni Plant, Toshiba Ceramics Co., Ltd. (72) Inventor Satoshi Nakao 2954-10 Tana, Sagamihara-shi, Kanagawa Prefecture (72) Inventor Takanori Saito 2736 Oshima, Oshima, Sagamihara, Kanagawa Prefecture (72) Inventor Nagae Nagase 8-1--14-605, Kiyoshi Shin, Sagamihara, Kanagawa Prefecture (72) Inventor Toshiyuki Makiya 2-1-22-101F, Higashicho, Akishima City, Tokyo Over-time (reference) 5F045 BB15 EK08 EK21 EM02 EM09

Claims (11)

[Claims] 1. A heating element housed in a quartz glass body, a heating surface formed on an upper surface of the quartz glass body, and a lower surface of a peripheral edge portion of a wafer provided integrally with and protruding from the heating surface. A heater with a wafer holder, comprising: a wafer holder to be supported; and a gap formed between the lower surface of the wafer and the heating surface when the wafer is placed on the wafer holder. 2. A first heating element housed inside a quartz glass body, a first heating surface formed on an upper surface of the quartz glass body, and integrally provided so as to protrude from the first heating surface. And a first gap formed between the lower surface of the wafer and the first heating surface when the wafer is placed on the wafer holder. A first heater section, a second heating element housed inside the quartz glass body, a second heating surface formed on the lower surface of the quartz glass body, and a wafer holder of the first heater section. A heater with a wafer holder, comprising: a second heater section having a second gap formed between the upper surface of the wafer and the second heating surface when the wafer is mounted. 3. The heater with a wafer holder according to claim 2, wherein the first heater section and the second heater section are integrally formed. 4. The wafer holder according to claim 1, wherein a gap formed between the lower surface of the wafer and the heating surface is in a range of 0.5 to 10 mm. heater. 5. The heater with a wafer holder according to claim 2, wherein a gap formed between an upper surface of the wafer and the heating surface is in a range of 0.5 to 10 mm. 6. A heat equalizing plate is provided between a lower surface of the wafer and the heating surface.
A heater with a wafer holder according to claim 2. 7. A heat equalizing plate is provided between an upper surface of the wafer and the heating surface.
A heater with a wafer holder according to claim 6. 8. The heat equalizing plate is made of any one of a silicon carbide material, a carbon material, a silicon carbide-coated carbon material, a silicon carbide-coated silicon carbide material, and a single crystal silicon material. A heater with a wafer holder according to claim 7. 9. The heater with a wafer holder according to claim 1, wherein the wafer holder is provided with a cutout portion cut out and communicating with the gap. 10. The quartz glass body in which a heating element is housed has a continuous groove of a predetermined pattern formed on the surface of one quartz glass plate, and carbon fibers having a diameter of 5 to 15 μm are bundled in the groove. The wire heating element formed by knitting a plurality of fiber bundles is arranged, and another quartz glass plate is fused and integrated on the surface of the heating element. Heater with wafer holder. 11. The heater with a wafer holder according to claim 10, wherein the carbon wire heating element is made of a carbon fiber material having an impurity content of 10 ppm or less on an ash basis.