JP2009218420A - Wafer holding body, and semiconductor manufacturing apparatus - Google Patents

Abstract

A wafer holder capable of dramatically improving the cooling rate of a wafer mounting table and at the same time improving the temperature rising rate, and a semiconductor manufacturing apparatus on which the wafer holder is mounted.
A wafer mounting surface on which a wafer is mounted, a wafer mounting table having a heating body, and a wafer mounting table support for supporting the wafer mounting table from the opposite side of the wafer mounting surface are provided. Furthermore, a wafer holder provided with a refrigerant injection module for injecting a refrigerant toward a surface opposite to the wafer mounting surface of the wafer mounting table, and a semiconductor manufacturing apparatus including the wafer holder.
[Selection] Figure 1

Description

  The present invention relates to a wafer holder used in a semiconductor manufacturing apparatus, and more particularly to a single wafer type wafer holder used in a field requiring rapid heating and rapid cooling, and a semiconductor manufacturing apparatus equipped with the same. . In particular, the present invention relates to a wafer holder that can be suitably used as a CVD susceptor, a plasma CVD susceptor, an etching susceptor, and an ashing susceptor used for film formation, and a semiconductor manufacturing apparatus on which the wafer holder is mounted.

  Conventionally, in a semiconductor manufacturing process, processing such as film formation, etching, and ashing is performed by heating a wafer or generating plasma. As a wafer holder used in these processes, a wafer holder made of metal or ceramics having excellent corrosion resistance is known.

  For example, in Japanese Examined Patent Publication No. 6-28258, a ceramic heater part installed in a container, a heating body is embedded, and a wafer heating surface is provided, and the heater part is provided between the container and the ceramic heater part. A wafer holder is described having a ceramic convex cylindrical support that forms an airtight seal.

  Moreover, it is usually used as a low temperature chamber or a high temperature chamber in an apparatus having a plurality of chambers as a set, depending on the process temperature. When changing the temperature of the process in this way, it is a common practice to prepare a plurality of chambers.

Japanese Unexamined Patent Application Publication No. 2004-14655 discloses a movable cooling module. According to this method, the temperature can be raised and cooled with a single wafer holder.
Japanese Patent Publication No. 6-28258 JP 2004-14655 A

  In recent years, in a semiconductor manufacturing process, an improvement in throughput has been demanded, and accordingly, a cooling rate and a temperature raising rate of a wafer holder have been demanded. However, in the case of the wafer holder described above, although a ceramic heater for heating the wafer and a cooling module for cooling the wafer are attached to the wafer, a sufficient cooling rate and heating rate are not necessarily obtained. It is becoming a situation that can not be said.

  In order to increase the cooling rate of the wafer mounting table, it is conceivable to cool the cooling module quickly. For this reason, a coolant channel is formed inside the cooling module formed of metal or the like, and the coolant is cooled through the channel. Has also been proposed. However, even if such a configuration is adopted, the wafer mounting table is cooled by bringing the cooling module into contact with the wafer mounting table, that is, indirectly cooling via the cooling module. I couldn't expect a dramatic increase in speed. In addition, even during heating, since the cooling module is in contact with the wafer mounting table, the cooling module is also heated in addition to the wafer mounting table, and a sufficient heating rate for heating the wafer mounting table could not be obtained. .

  Therefore, in the present application, a wafer holder capable of dramatically improving the cooling rate of the wafer mounting table and improving the temperature rising rate as compared with the conventional one, and a semiconductor manufacturing apparatus equipped with the wafer holder are provided. The purpose is to provide.

  In this invention, the said subject can be solved by cooling a wafer mounting base with a refrigerant | coolant directly by injecting a refrigerant | coolant directly with respect to the wafer mounting base which became high temperature.

That is, the present invention relates to claim 1,
A wafer mounting surface on which a wafer is mounted, and a wafer mounting table including a heating body;
A wafer mounting table support for supporting the wafer mounting table from the opposite side of the wafer mounting surface;
Furthermore, a wafer holder is provided, wherein a coolant injection module is provided for injecting a coolant toward a surface of the wafer mounting table opposite to the wafer mounting surface.

In the first aspect of the present invention, since the coolant is directly jetted onto the wafer mounting table and the wafer mounting table is directly cooled using the coolant injection module, the cooling rate can be remarkably increased. That is, it is a method in which the coolant is directly injected from the coolant injection module to the wafer mounting table and cooled, as opposed to the conventional method of cooling indirectly by flowing the coolant into the cooling module and bringing it into contact with the wafer mounting table. Can be cooled efficiently.
In addition, during heating, the heat generated from the heating element is not wasted when heating the cooling module that is in contact with the wafer mounting table, and the wafer mounting table is heated. The mounting table can be heated.

The invention described in claim 2
The wafer mounting table support is a cylindrical support coupled to the wafer mounting table,
2. The wafer holder according to claim 1, wherein the coolant injection module is provided in a gap formed by the wafer mounting table and the cylindrical support. 3.

According to the second aspect of the present invention, since the wafer mounting table support body is formed by the integral cylindrical support body, it is not necessary to make the structure of the wafer holder complicated, and the manufacturing cost can be reduced.
Further, since the refrigerant injection module is provided in a gap formed by the wafer mounting table and the cylindrical support coupled to the wafer mounting table, the refrigerant injected from the refrigerant injection module is outside the gap. Therefore, it can be efficiently recovered when the refrigerant is recovered.

The invention according to claim 3
The wafer mounting table support comprises a support column coupled to the wafer mounting table, and a cylindrical support column support that supports the support column,
The cover member covers the outer periphery of the wafer mounting table to the outer periphery of the support pillar support,
The wafer holder according to claim 1, wherein the refrigerant injection module is provided in a gap formed by the wafer mounting table and the cover member.

According to the third aspect of the present invention, since the support column and the support column support are used as the wafer mounting table support and the outer periphery is covered with the cover member, it is not necessary to replace the entire wafer mounting table support at a time. Is also easy.
In addition, since the refrigerant injection module is provided in the gap formed by the wafer mounting table and the cover member, the refrigerant injected from the refrigerant injection module is less likely to leak out of the gap, and during the recovery of the refrigerant It can be recovered efficiently.

The invention according to claim 4
The wafer holder according to any one of claims 1 to 3, further comprising a refrigerant recovery unit that recovers the refrigerant injected from the refrigerant injection module.

  In the invention of claim 4, since the refrigerant recovery unit that recovers the injected refrigerant is provided, the refrigerant can be reused, and the refrigerant can be used efficiently. Further, it is preferable because scattering of the refrigerant into the atmosphere can be suppressed.

The invention described in claim 5
The wafer holder according to claim 4, wherein the refrigerant recovery part also serves as the cylindrical support.

  In the invention of claim 5, since the refrigerant recovery part also serves as the cylindrical support, it is not necessary to make the structure of the wafer holder more complicated and the increase in the number of parts can be suppressed, so that the manufacturing cost can be reduced. Can be planned.

The invention described in claim 6
The said refrigerant | coolant injected from the said refrigerant | coolant injection module is a refrigerant | coolant which evaporates by contact with the wafer mounting base heated by the said heating body. This is a wafer holder.

  In the invention of claim 6, since the refrigerant ejected from the refrigerant ejection module is a refrigerant that is vaporized by contact with the wafer mounting table, that is, a refrigerant having a boiling point lower than the temperature of the heated wafer mounting table, The contacted refrigerant boils and vaporizes instantaneously when it comes into contact with the wafer mounting table. And when the refrigerant evaporates, the heat of vaporization is taken away from the wafer mounting table, so that a large amount of heat can be taken from the wafer mounting table in a short time, and the wafer mounting table can be rapidly cooled. Efficient.

The invention described in claim 7
The wafer mounting table and the cylindrical support are hermetically sealed,
Or
7. The wafer holding according to claim 2, wherein the wafer mounting table and the cover member, and the cover member and the support column support are hermetically sealed. 8. Is the body.

  In the invention of claim 7, since the wafer mounting table and the cylindrical support body and the cover member, and the cover member and the support column support body are hermetically sealed, the refrigerant does not leak out from the gap portion, The mounted wafer is not adversely affected. Moreover, scattering of the refrigerant into the atmosphere can be suppressed, and an increase in the amount of refrigerant used can be suppressed.

The invention according to claim 8 provides:
Furthermore, each of the wafer mounting table and the cylindrical support is hermetically sealed,
Or
Each of the wafer mounting table and the support pillar support is hermetically sealed,
3. A cylindrical protective member capable of disposing a power supply member to the heating body and / or a temperature measuring member for monitoring a temperature rise state is provided in the gap. A wafer holder according to claim 7.

  In the invention of claim 8, since the cylindrical protective member hermetically sealed with each of the wafer mounting table and the cylindrical support or support column support is provided, temperature measurement such as a power supply member such as an electrode or a thermocouple is provided. The members and the like can be shielded from the refrigerant, and the functions such as insulation can be prevented from being deteriorated when these members come into contact with the refrigerant. That is, it is possible to prevent a decrease in reliability as a wafer holder.

The invention according to claim 9 is:
Furthermore, the supporting member which supports the said wafer mounting base is provided between the said wafer mounting base and the lower part of the said cylindrical support body of the said space | gap part, The Claim 2 or Claim characterized by the above-mentioned. A wafer holder according to any one of claims 4 to 8.

In a ninth aspect of the present invention, the support member for supporting the wafer mounting table is provided between the wafer mounting table and the lower portion of the cylindrical support in the gap, thereby providing a wafer mounting table. However, since it is supported not only by the upper part of the cylindrical support but also by the support member, the deformation of the wafer mounting table can be further prevented, and the thermal uniformity can be further improved.
A plurality of support members are preferably provided. In addition, it is preferable that the lower part of the cylindrical support has a structure that is as parallel as possible with the wafer mounting table, so that a support member can be easily provided. Just design.

  Furthermore, a coupling member such as a screw that couples the wafer mounting table and the cylindrical support can also be used as the support member. If comprised in this way, a wafer mounting base will be supported by a cylindrical support body via a coupling member, and a deformation | transformation of a wafer mounting base can be prevented more, and the dispersion | variation in the temperature distribution of a wafer can be made smaller. it can.

The invention according to claim 10 is:
A wafer holder housed in a chamber,
10. The wafer holder according to claim 2, wherein the gap is shielded from the atmosphere in the chamber. 11.

  In the invention of claim 10, since the gap and the atmosphere in the chamber are shut off, each member arranged in the gap is protected from halogen-based corrosive gases such as fluorine and chlorine used in the chamber. Thus, the durability of the wafer holder can be maintained, which is preferable.

The invention according to claim 11
A semiconductor manufacturing apparatus on which the wafer holder according to claim 1 is mounted.

  In the invention of claim 11, since the semiconductor manufacturing apparatus is equipped with a wafer holder capable of improving the cooling rate and at the same time increasing the heating rate, the wafer processing capacity can be improved. , Can increase productivity.

  According to the present invention, there is provided a wafer holder capable of dramatically improving the cooling rate of the wafer mounting table and also improving the temperature rising rate as compared with the prior art, and a semiconductor manufacturing apparatus equipped with the wafer holder. Can be provided.

  Hereinafter, the present invention will be described in detail with respect to its embodiments. Note that the present invention is not limited to the following embodiments. Various modifications can be made to the following embodiments within the same and equivalent scope as the present invention.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of a wafer holder accommodated in a chamber, and a cylindrical support coupled to the wafer mounting table is employed as the wafer mounting table support.

In FIG. 1, a wafer holder 1 is provided with a wafer mounting surface 2, a wafer mounting table 3 having a heating body 9 therein, and a wafer mounting table 3 coupled with a wafer mounting table 3 by an airtight seal 4a. A cylindrical support 4 that supports the wafer mounting table 3 is provided from the opposite side of the surface 2, and the gap 5 formed by the wafer mounting table 3 and the cylindrical support 4 is formed on the wafer mounting table 3. A refrigerant injection module 6 for cooling the wafer mounting table 3 by injecting the refrigerant is provided.
The cylindrical support 4 also serves as the recovery part 7, the lower part is formed in a funnel shape, and the bottom part is a refrigerant discharge port 8 in the recovery part 7.
Further, the gap portion 5 is blocked from the atmosphere in the chamber (portion surrounded by the wall surface portion 13 of the chamber) by the hermetic seal portions 4a and 15.

  The refrigerant injection module 6 includes a refrigerant supply pipe 61, a refrigerant injection head 62 attached to the tip of the refrigerant supply pipe 61, and a refrigerant supply source (not shown) connected to the other end of the refrigerant supply pipe 61. Yes. The refrigerant supply pipe 61 is introduced into the cylindrical support 4 from below, and is arranged so that the refrigerant ejection head 62 is positioned below the wafer mounting table 3 in the gap 5.

  Then, the refrigerant jet head 62 sprays the refrigerant supplied to the refrigerant supply pipe 61 evenly over the entire lower surface of the wafer mounting table 3, as shown by the arrows in FIG. It is designed so that the spraying amount per unit area is the same. This is because, even during cooling, the wafer mounted on the wafer mounting surface 2 is often required to have a uniform temperature, and when the coolant is sprayed evenly, only that portion is rapidly cooled and cannot be sprayed. This is because the cooling rate of the other portions is significantly slowed down, and the cooling rate becomes uneven and the thermal uniformity of the wafer is disturbed.

The shape of the refrigerant jet head 62 is not particularly limited. For example, a refrigerant jet head having the shape shown in FIGS. 2 and 3 may be used.
In FIG. 2, the refrigerant ejection head 62 is formed in a hollow disk shape, and a large number of ejection holes 62 a are provided on the upper surface (side toward the wafer mounting table 3). A refrigerant supply pipe 61 is connected to the lower surface.
The refrigerant is pumped from the refrigerant supply pipe 61 to the refrigerant ejection head 62 and is ejected radially from the numerous ejection holes 62 a toward the wafer mounting table 3, so that the refrigerant can be sprayed evenly onto the wafer mounting table 3.

In FIG. 3, the refrigerant jet head 62 is formed of a spiral pipe, and a large number of jet holes 62a are provided at a constant pitch on the upper surface (side toward the wafer mounting table 3). . The tip of the pipe is closed, and the refrigerant supply pipe 61 is connected to the other end.
The refrigerant is pumped from the refrigerant supply pipe 61 to the refrigerant ejection head 62 and is ejected radially from the numerous ejection holes 62 a toward the wafer mounting table 3, so that the refrigerant can be sprayed evenly onto the wafer mounting table 3.

  The material of the refrigerant injection module is not particularly limited as long as it is a material that is corrosion resistant to the refrigerant because it contacts the high-temperature refrigerant after contacting the wafer mounting table, and examples include metals such as stainless steel, aluminum, and copper. can do.

The refrigerant that can be used is not particularly limited, and may be appropriately selected according to the cooling temperature of the wafer mounting table and the processing purpose. For example, water, alcohol, acetone, a mixed solvent thereof, or a halogen-based solvent such as fluorinate. However, if a solvent having a boiling point lower than the temperature of the wafer mounting table to which the refrigerant is jetted is used, the jetted refrigerant comes into contact with the lower surface of the wafer mounting table and, at the same time, boils and vaporizes, and the wafer Since heat is taken away from the mounting table, the cooling rate can be increased, which is preferable.
However, depending on the material of the wafer mounting table, the temperature distribution in the wafer mounting table may be disturbed by spraying the coolant on the local area, and the wafer mounting table may be deformed. If the wafer mounting table is deformed, not only the thermal uniformity is disturbed, but if the thermal shock is large, the wafer mounting table may be damaged in the worst case, which is not preferable.

And it is preferable that a refrigerant | coolant is continuously injected from a refrigerant | coolant injection module. By continuously ejecting, the high-temperature refrigerant vaporized by taking the heat of the wafer mounting table is cooled by the newly ejected refrigerant and is liquefied again. As a result, it is possible to suppress a decrease in the cooling effect caused by the vaporized refrigerant filling the gap. By recovering the liquefied refrigerant from the discharge port 8 and returning it to the refrigerant supply source, the refrigerant can be reused and the amount of refrigerant consumed can be suppressed.
There are no particular restrictions on the amount of refrigerant injected, and it is preferable to spray a refrigerant having a temperature as low as possible at a high flow rate in order to increase the cooling rate.

  The wafer mounting table 3 is not particularly limited in material. However, in order to make the temperature distribution of the wafer mounted on the wafer mounting surface 2 uniform during heating and cooling, a material having high thermal conductivity is used. Specifically, a material having a thermal conductivity of 50 W / mK or more is used. Further, the density x specific heat of the wafer mounting table 3 at this time is preferably less than 4. By having such characteristics, the heat capacity of the wafer mounting table can be reduced, and the temperature can be efficiently raised and cooled.

  Further, when the coolant is sprayed and cooled rapidly, the wafer mounting table 3 is deformed so as not to cause a soaking disturbance, or the wafer mounting table 3 is not damaged by the thermal shock. Excellent material is used.

Specific examples of preferable materials include aluminum, copper, tungsten, molybdenum, and other materials having high thermal conductivity, mixtures thereof, alloys, and the like. Examples of ceramics include silicon carbide and aluminum nitride having high thermal conductivity. Moreover, silicon nitride can be mentioned as ceramics having high strength.
As for the composite of ceramic and metal, those having relatively high thermal conductivity, those having high strength, and those having a low thermal expansion coefficient can be preferably used because of their high thermal shock coefficient. For example, Al-SiC, Si-SiC, Al-AlN, Al-Si-SiC, and the like can be given.

In addition, when these materials are used in a halogenated gas atmosphere such as a fluorine-based gas or a chlorine-based gas, a film of nickel, nickel fluoride, or the like is formed on the surface of the wafer mounting table 3 for the purpose of improving corrosion resistance. Is also possible.
When nickel plating is performed on the surface of the wafer mounting table 3, the nickel plating thickness is preferably 0.5 μm or more. In the case of a nickel plating thickness of less than 0.5 μm, the plating is easily peeled off due to surface oxidation or scratches, and the portion may be corroded. A plating thickness of 2 μm or more is more preferable because the above-described problem hardly occurs.

  In the present embodiment, the wafer mounting table 3 includes a heating body 9. A method for forming the heating element 9 is not particularly limited, and a known method can be adopted. However, when the refrigerant is directly sprayed on the heating element 9, depending on the type of the refrigerant, the heating element 9 may have poor insulation. It may happen.

  Therefore, for example, in the case of insulating ceramics such as aluminum nitride and silicon nitride, it is conceivable to embed a high-melting point metal heating element 9 formed by pattern printing. Moreover, the circuit pattern of the heating body 9 can be formed on the opposite side of the wafer placement surface 2 by a technique such as printing, and the circuit pattern can be covered with an insulator such as glass. For conductive materials such as metals, metal-ceramic composites, silicon carbide, etc., a metal foil such as stainless steel or nichrome is formed with a technique such as etching, and heat-resistant resin or mica is used. It is also possible to cover and place the wafer mounting table 3 on the surface opposite to the wafer mounting surface 2 by a method such as screwing. Further, a plate such as a ceramic plate or a metal plate can be installed on the back side, and the heating body 9 can be uniformly adhered to the wafer mounting table 3 by screwing. Further, the wafer mounting table 3 can be divided into two in the thickness direction, and the heating body 9 can be sandwiched between the divided surfaces.

  For the cylindrical support 4, a material having a lower thermal conductivity than that of the wafer mounting table 3 is used. For example, when the temperature of the wafer mounting table 3 is rapidly lowered, if the thermal conductivity of the cylindrical support 4 is high, the heat from the cylindrical support 4 is supplied to the wafer mounting table 3 to reduce the cooling rate. Because. In particular, when the wafer mounting table 3 is heated and used with the heating body 9 and then cooled, the tendency is particularly remarkable. Considering these things, as the cylindrical support 4, stainless steel or the like is preferable for the metal in terms of thermal conductivity. Further, if necessary, the surface may be plated with nickel in order to improve the corrosion resistance. In addition, since ceramic materials have higher corrosion resistance than metals, various materials having low thermal conductivity can be selected. For example, alumina, mullite, a composite thereof, silicon nitride, cordierite, quartz, or the like can be used. Among these, in particular, mullite-alumina composite has low thermal conductivity and excellent heat insulation. Therefore, when the wafer mounting table 3 is heated, the heat from the wafer mounting table 3 is prevented from being escaped, and the temperature can be raised quickly. Can be realized. In addition, heat transfer from the chamber and other parts can be cut off during cooling, which is preferable because it can be rapidly cooled. Alumina is preferable because it has high rigidity and can be thinned, so that the heat capacity can be reduced and the temperature can be efficiently raised and cooled.

  The wafer mounting table 3 and the cylindrical support 4 are coupled via an airtight seal portion 4 a to form a gap portion 5. As the hermetic seal, an O-ring, a heat-resistant gasket, or the like can be used. In general, an O-ring can be used if the wafer mounting table 3 is used at a temperature of about 250 ° C. or lower, and if it is used at a temperature higher than that, a gasket made of nickel or stainless steel is used in consideration of corrosion from atmospheric gases. Can be used.

  The air gap 5 is shielded from the atmosphere in the chamber by the hermetic seal portion 4a, so that a halogen-based corrosive gas such as fluorine or chlorine used in the chamber can be used for the heating body installed in the air gap 5. The power supply member, a temperature measuring element such as a thermocouple, the refrigerant injection module 6 and the like are protected.

  Further, the gap 5 has an atmospheric pressure atmosphere that is the same as the atmosphere outside the chamber. This is because, when the gap 5 is in a reduced pressure atmosphere, a short circuit or a spark occurs between the electric circuits.

  The gap 5 can be made into a reduced pressure atmosphere or a vacuum by a decompression means not shown. In this case, the electrode member is preferably covered with insulation in order to prevent sparks between circuits. Although there are no particular restrictions on the insulating coating, for example, when the temperature of the electrode portion is up to about 200 ° C., a heat-resistant resin such as a fluorine-based heat-shrinkable resin can be used. Moreover, in the case of high temperature, a ceramic material can be sprayed on an electrode, or a ceramic pipe can be installed. In any case, for example, if there are two electrodes, it is preferable to insulate at least one of the electrodes. Moreover, since the deformation | transformation of the wafer mounting base 3 is suppressed by making the space | gap part 5 into a vacuum comparable as the inside of a chamber, reliability can be made higher.

On the other hand, when the inside of the chamber is in a vacuum atmosphere, a pressure difference of 1 atm maximum is generated between the gap portion 5 and the chamber, and a large pressure is applied to the wafer mounting table 3, so that the wafer mounting table 3 may be deformed. .
If the wafer mounting table is deformed, the variation in the distance between the wafer and the wafer mounting table increases, the temperature distribution of the wafer varies, and the wafer mounting table itself may be damaged.

  In order to prevent this deformation, a support member can be provided between the wafer mounting table 3 and the cylindrical support 4. Since the support member supports and fixes the wafer mounting table 3 together with the cylindrical support body 4, the support points increase and deformation can be prevented.

  An example of the support member is a coupling member such as a screw. In this case, the screw hole 11 is formed on the wafer mounting table 3 side, the through hole 12 is formed on the cylindrical support body 4 side, and the screw 10 Is fixed to the screw hole 11 through the through hole 12. Thereby, the deformation | transformation of the wafer mounting base 3 by an internal and external pressure difference can be prevented. For example, in the 12-inch wafer holder 1, it is preferable that the screws 10 be fixed at least three locations equally on the same circumference. By arranging them uniformly, the amount of deformation can be reduced. Furthermore, the deformation of the wafer mounting table 3 can be more effectively reduced by arranging the screw 10 on the center side of the three locations. Further, it is preferable that the number of screws 10 to be fixed is large because deformation can be more effectively suppressed. However, since the assembly becomes complicated, it may be appropriately designed according to the required flatness of the wafer mounting table 3.

  The material of the support member such as the screw 10 can be used without any particular limitation. For example, stainless steel, Kovar, tungsten, molybdenum, nickel, and alloys thereof can be used. Since the screw 10 couples the wafer mounting table 3 and the cylindrical support 4, heat is inevitably transmitted to the cylindrical support 4 through the screw 10 during use at a high temperature. Therefore, conversely, when the wafer mounting table 3 is cooled, heat is transferred from the screw 10 toward the wafer mounting table 3, which causes a decrease in the cooling rate. As a preferable material, Kovar or stainless steel is preferably the main component. Since these materials have a relatively high elastic modulus and particularly low thermal conductivity, they are preferable because they have an excellent heat insulating effect like the cylindrical support 4 described above. Moreover, in order to improve the corrosion resistance with respect to a refrigerant | coolant, films | membranes, such as nickel and nickel fluoride, can also be formed in the surface of these materials.

  Ceramics can also be used for the support member, and ceramics are preferable because of their relatively high elastic modulus and particularly low thermal conductivity. These support members and coupling members preferably have a thermal expansion coefficient comparable to that of the cylindrical support 4. This is because the warp due to the difference in thermal expansion coefficient can be reduced as the difference in thermal expansion coefficient between the temperature rise and the temperature drop is smaller.

  Reference numeral 14 in the figure denotes a cylindrical protective member, which is a thermocouple for measuring the temperature of the power supply member 9a to the heating body 9 or the wafer mounting table 3, and a temperature measuring element such as a resistance temperature detector. It protects against the influence of. The cylindrical protective member 14 is preferably made of an insulating material. Further, when the material of the wafer mounting table 3 is ceramics or a composite of ceramics and metal, alumina, mullite, and these composites can be preferably used since they have a relatively small coefficient of thermal expansion. The upper end portion of the cylindrical protection member 14 is connected to the wafer mounting table 3 via an airtight seal portion 14a, and the lower end portion of the cylindrical protection member 14 is connected to the inner wall of the cylindrical support body 4 via an airtight seal portion 14b. ing. Note that the cylindrical protective member 14 is not necessary when the refrigerant is always an excellent insulator even at high temperatures, but the cylindrical protective member is necessary when the refrigerant is likely to exhibit conductivity such as water. .

  Reference numeral 30 in the drawing denotes a cylindrical support column, which is provided for protecting or reinforcing the screw 10. As the cylindrical support column 30, like the cylindrical protection member 14, alumina, mullite, or a composite thereof can be preferably used. In addition, the cylindrical support pillar 30 can also be abbreviate | omitted according to a use.

  As described above, the wafer holder 1 having the cooling system described in the present invention dramatically increases the cooling rate of the wafer holder 1 as compared with the wafer holder having the cooling system using the conventional cooling module. Therefore, an excellent throughput can be realized by mounting on an apparatus such as an etcher, CVD, plasma CVD, or ashing.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view of the wafer holder, and the wafer mounting table support includes a support column 20 and a cylindrical support column support 21 coupled to the wafer mounting table 3. In FIG. 4, only the main part is shown, and the cylindrical protective member and the like are not shown.

In FIG. 4, the wafer holder 1 is provided with a wafer mounting table 3 having a wafer mounting surface 2 and a heating body 9 inside. The wafer mounting table 3 is coupled to the wafer mounting table 3. The support column 20 is supported, and a cylindrical support column support 21 that supports the support column 20. The outer periphery of the wafer mounting table 3 and the outer periphery of the support column support 21 are covered with a cover member 22. By covering with the cover member 22 and further sealing the airtight seal portions 4a and 4b, the gap portion 5 is provided, and the gap portion 5 is provided with the refrigerant injection module 6.
The support column support 21 is formed in a funnel shape and serves as a refrigerant discharge port to a collection unit (not shown).

  A plurality of support pillars 20 are arranged on the concentric circumference of the wafer holder 1 between the wafer mounting table 3 and the support pillar support 21. FIG. 4 shows an example in which four lines are provided at intervals of 90 degrees. In addition, it is preferable that the support pillar 20 is cylindrical because a heat insulating effect is obtained.

As the support column 20, the support column support 21, and the cover member 22, a material having a thermal conductivity lower than that of the wafer mounting table 3 is used as in the case of the cylindrical support. The reason is the same as the reason described in the first embodiment. In addition, it is preferable to use the same thing as the case of Embodiment 1 also about the wafer mounting base 3 and a refrigerant | coolant.
As for the refrigerant injection module 6, the refrigerant injection module similar to that in FIG. 1 is used in FIG. 4, but the refrigerant injection module shown in FIGS.

  The present invention will be further described below with reference to examples.

In this embodiment, the wafer holder shown in FIG. 2 is used.
After applying W paste as a circuit of the heating body 9 to an AlN substrate having a diameter of 330 mm and a thickness of 5 mm and firing at 1800 ° C., Al ₂ O ₃ —Y ₂ O ₃ —AlN powder is applied, and another AlN substrate is applied. And bonded at a pressure of 1800 ° C. and 20 t to form an AlN heater (wafer mounting table 3).

  Also, two SiC, Si-SiC, and Al-SiC substrates each having a diameter of 330 mm and a thickness of 5 mm were prepared, and a resistance heating element in which stainless steel foil was etched was sandwiched with mica as a heating element 9, and screwed between these substrates. The wafer mounting table 3 was obtained by sandwiching. Furthermore, an aluminum heater in which a sheath heater having a diameter of 330 mm and a thickness of 10 mm was embedded was also prepared.

  A cylindrical support 4 is attached to the wafer mounting table 3, and a 10 mm pitch is formed in the upper surface (wafer mounting table 3 side) of a 300 mm diameter hollow disk-shaped stainless steel container in the inside (gap portion 5). The refrigerant injection module 6 having the refrigerant injection head 62 provided with the refrigerant injection holes 62a having a diameter of 1 mm was installed. And the discharge port 8 for collect | recovering refrigerant | coolants was provided in the lower part of the cylindrical support body 4. As shown in FIG.

The electrode for the heating body 9 for heating the wafer mounting table 3 is covered with a tube of mullite-Al ₂ O ₃ composite, sealed with glass so as not to come into contact with the refrigerant, and the cylindrical support 4 The chamber was hermetically sealed with an O-ring.
Then, a wafer thermometer having a diameter of 300 mm was installed on the wafer mounting table 3, the temperature was increased at a rate of 20 ° C./min, and when the temperature was set to 90 ° C., the energization to the heating body 9 was interrupted. At the same time that the heating element 9 was turned off, the coolant was sprayed to cool to 50 ° C. The cooling rate at this time (time until reaching 50 ° C.) was measured. As the refrigerant, water having a boiling point of 90 ° C. and a fluorine-based refrigerant having a boiling point of 210 ° C. were used.

(Comparative example)

  As Comparative Example 1, the cooling rate was measured in the same manner as in Example 1 except that air was used instead of the refrigerant.

  As Comparative Example 2, an example using a conventional cooling module is shown. Two copper plates with a diameter of 300 mm and a thickness of 5 mm are prepared on the wafer mounting table 3, counterbored surfaces are formed on each other, a coolant channel is formed, and both are joined with silver solder, and a cooling module And using the wafer holder 1 having a contact-type cooling mechanism screwed to the wafer mounting table 3 while the cooling module is in contact with the lower surface of the wafer mounting table 3. Similarly, the cooling rate was measured in the same manner. Note that water having a boiling point of 90 ° C. was used as the refrigerant.

  The measurement results in Example 1 and Comparative Examples 1 and 2 are shown in Table 1.

  From the results shown in Table 1, it can be seen that according to the method of the present invention, the cooling rate is very excellent as compared with the conventional method (Comparative Example 2). It can be seen that the cooling rate is very slow when air that is not a refrigerant is used (Comparative Example 1).

  The wafer holder 1 used in Example 1 was heated to 200 ° C., and similarly the cooling rate to 50 ° C. was measured. The results are shown in Table 2.

  From the results shown in Table 2, it can be seen that when water is used as the refrigerant, water has a lower boiling point than that of the fluorine-based refrigerant and takes a large amount of heat of vaporization, so that the cooling rate is faster.

  The same test as in Example 2 was performed. However, the wafer holder 1 was installed in a vacuum chamber. For this reason, the space between the cylindrical support 4 and the wafer mounting table 3 was fixed at three locations by a Kovar coupling member and at the portion of the PCD 170. In addition, an O-ring is hermetically sealed between the cylindrical support 4 and the wafer mounting table 3 and between the cylindrical support 4 and the chamber, and the inside of the cylindrical support 4 (gap portion 5) is The atmosphere was atmospheric. The results are shown in Table 3.

表３に示す結果から、本実施例においても、実施例２と同様の結果が得られ、真空チャンバー内にウエハ保持体を設置した場合でも、本発明の冷却手法が有効であることが分かる。

From the results shown in Table 3, it can be seen that also in this example, the same result as in Example 2 is obtained, and the cooling method of the present invention is effective even when the wafer holder is installed in the vacuum chamber.

The wafer holder 1 used in Example 3 was heated to 200 ° C., a wafer thermometer was placed on the wafer placement surface 2, and the thermal uniformity was measured 1 minute after reaching 200 ° C. At this time, those without a connecting member were also compared at the same time. The results are shown in Table 4.
Further, after the soaking measurement, the wafer thermometer was removed, and the flatness of the wafer mounting surface 2 at 200 ° C. was measured with a laser displacement meter. The results are also shown in Table 4.

  From the results shown in Table 4, it can be seen that when the inside of the chamber is in a vacuum or a reduced-pressure atmosphere, the flatness of the wafer mounting surface 2 is more stable and the heat uniformity is better when the coupling member is used.

A similar test was performed on the wafer mounting table 3 used in Example 1 by removing the mullite-Al ₂ O ₃ pipe covering the electrodes. As a result, the same results as in Example 1 were obtained with the fluorine-based refrigerant. Similar results were obtained when the coolant was water. And immediately after cooling (50 degreeC reach | attainment), when it supplied with electricity to the heating body 9, when the refrigerant | coolant was water, the short circuit occurred. However, those using a fluorine-based refrigerant could be heated as in the previous time. Also, the shorted product could be heated without being short-circuited after the dry air was introduced into the cylindrical support 4 and sufficiently dried.
From this result, it is not essential to provide a pipe covering the electrode, that is, a cylindrical protective member, but it is preferable to provide a cylindrical protective member because an inexpensive refrigerant such as water can be used without problems.

It is a schematic sectional drawing of an example of the wafer holder which concerns on this invention. It is a figure explaining another example of the wafer holder which concerns on this invention, (a) is a schematic sectional drawing of a wafer holder, (b) is a top view of the refrigerant | coolant injection head of a refrigerant | coolant injection module. It is a figure explaining another example of the wafer holder which concerns on this invention, (a) is a schematic sectional drawing of a wafer holder, (b) is a top view of the refrigerant | coolant injection head of a refrigerant | coolant injection module. It is a schematic sectional drawing of another example of the wafer holder which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer holding body 2 Wafer mounting surface 3 Wafer mounting base 4 Cylindrical support body 4a, 4b, 14a, 14b, 15 Airtight seal | sticker part 5 Cavity part 6 Refrigerant injection module 7 Recovery part 8 Outlet 9 Heating body 9a Power supply member 10 Screw 11 Screw hole 12 Through-hole 13 Wall surface portion 14 of the chamber Cylindrical protection member 20 Support column 21 Support column support 22 Cover member 30 Cylindrical support column 61 Refrigerant supply pipe 62 Refrigerant injection head 62a Injection hole

Claims (11)

A wafer mounting surface on which a wafer is mounted, and a wafer mounting table including a heating body;
A wafer mounting table support for supporting the wafer mounting table from the opposite side of the wafer mounting surface;
The wafer holder is further provided with a refrigerant injection module for injecting a refrigerant toward a surface opposite to the wafer mounting surface of the wafer mounting table. The wafer mounting table support is a cylindrical support coupled to the wafer mounting table,
The wafer holder according to claim 1, wherein the refrigerant injection module is provided in a gap formed by the wafer mounting table and the cylindrical support. The wafer mounting table support comprises a support column coupled to the wafer mounting table, and a cylindrical support column support that supports the support column,
The cover member covers the outer periphery of the wafer mounting table to the outer periphery of the support pillar support,
The wafer holder according to claim 1, wherein the coolant injection module is provided in a gap formed by the wafer mounting table and the cover member.   The wafer holder according to any one of claims 1 to 3, further comprising a refrigerant recovery unit that recovers the refrigerant injected from the refrigerant injection module.   The wafer holder according to claim 4, wherein the refrigerant recovery part also serves as the cylindrical support.   The said refrigerant | coolant injected from the said refrigerant | coolant injection module is a refrigerant | coolant which evaporates by contact with the wafer mounting base heated by the said heating body. Wafer holder. The wafer mounting table and the cylindrical support are hermetically sealed,
Or
7. The wafer holding according to claim 2, wherein the wafer mounting table and the cover member, and the cover member and the support column support are hermetically sealed. 8. body. Furthermore, each of the wafer mounting table and the cylindrical support is hermetically sealed,
Or
Each of the wafer mounting table and the support pillar support is hermetically sealed,
3. A cylindrical protective member capable of disposing a power supply member to the heating body and / or a temperature measuring member for monitoring a temperature rise state is provided in the gap. The wafer holder according to claim 7.   Furthermore, the supporting member which supports the said wafer mounting base is provided between the said wafer mounting base and the lower part of the said cylindrical support body of the said space | gap part, The Claim 2 or Claim characterized by the above-mentioned. The wafer holder according to any one of claims 4 to 8. A wafer holder housed in a chamber,
10. The wafer holder according to claim 2, wherein the gap is cut off from the atmosphere in the chamber. 11.   11. A semiconductor manufacturing apparatus on which the wafer holder according to claim 1 is mounted.

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