JP2007184289A - Heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive heater which is hardly damaged basically without use of ceramics, and particularly useful as a gas shower substrate for a semiconductor manufacturing apparatus. <P>SOLUTION: This heater is formed by supporting and fixing an insulation-coated heating element 1 on the surface of one metallic support 3, or inserting it between two metallic supports 3 to fix it. Preferably, the insulating coating of the heating element is a flame spraying film of an insulating material such as oxide or a resin film of teflon resin, polyimide resin etc. Similarly, the metallic supports 3 may be insulation-coated, and particularly, when the metallic support is made of aluminum or aluminum alloy, it is preferable to form the insulating coating by anodized aluminum treatment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal heater, and more particularly to a heater that can be suitably used as a gas shower substrate of a semiconductor manufacturing apparatus.

  In a single wafer type semiconductor manufacturing apparatus that processes a semiconductor wafer when performing etching processing or film formation on the surface of the semiconductor wafer, it is caused by non-uniform gas flow in the apparatus. Thus, there is a problem that variations occur in the quality of etching and formed films. Therefore, a gas shower substrate has been proposed for preheating the gas introduced into the semiconductor manufacturing apparatus and at the same time spraying and supplying the semiconductor wafer uniformly.

For example, Japanese Patent No. 3224629 describes a gas supply member in which a plurality of gas introduction holes are provided in a disk-shaped substrate made of ceramics, and a resistance heating element is embedded in the disk-shaped substrate. Specifically, by using a gas supply member in which a resistance heating element is embedded in ceramics such as silicon nitride, alumina, sialon, and aluminum nitride and a large number of gas introduction holes are provided, a liquid at room temperature such as TiCl _{4 is obtained.} When introducing a gas containing the above material into the film forming apparatus, TiCl _{4 and the} like are prevented from condensing, and film formation and cleaning on the wafer can be performed stably.

  According to Japanese Patent Laid-Open No. 2001-274103, a ceramic sintered body base having a thickness of 5 mm or less and having a plurality of through holes, and a conductive layer formed on the ceramic sintered body base A gas shower unit for a semiconductor manufacturing apparatus having a heater circuit pattern is proposed. The publication also discloses a technique in which a second ceramic sintered body base material is bonded to a ceramic sintered body base material on which a conductive layer is formed with glass or the like.

Japanese Patent No. 3224629 JP 2001-274103 A

  The gas supply member described in the above-mentioned Japanese Patent No. 3224629 and the gas shower body described in Japanese Patent Laid-Open No. 2001-274103 are heaters that preheat the gas introduced into the semiconductor manufacturing apparatus, This is very useful as a means for uniformly supplying the gas onto the semiconductor wafer.

  However, since these conventional heaters or gas shower substrates are basically made of ceramics, there is a drawback that the cost is increased. Further, since it is necessary to form a large number of through-holes in the ceramic substrate for gas introduction, the strength is weakened, and there is a drawback that it is easily damaged by handling or vibration during attachment to the apparatus.

  The present invention has been made in view of such conventional circumstances, and is basically useful as a heater, particularly a gas shower substrate for a semiconductor manufacturing apparatus, which does not use ceramics, is inexpensive, and is not easily damaged. The object is to provide a heater.

  In order to achieve the above object, in the present invention, a heater is configured by supporting an insulatingly coated heating element on the surface of a metal support or sandwiching it between two metal supports. With such a structure, it is not necessary to use ceramics and not only can be manufactured at low cost, but also a heater that is not easily damaged can be obtained.

  That is, the first heater provided by the present invention is characterized by comprising a heat generating body coated with insulation and a metal support having the heat generating body supported and fixed on the surface. Further, the second heater provided by the present invention is characterized by comprising a heat generating body coated with insulation and two metal support bodies sandwiched and fixed on both sides of the heat generating body.

  In the first and second heaters of the present invention described above, the insulating coating applied to the heating element may be a sprayed film. The insulating coating applied to the heating element may be a resin film, and the resin film is preferably made of Teflon resin or polyimide resin.

  In the first and second heaters of the present invention described above, the metal support may be insulated. The insulating coating applied to the metal support can be a sprayed film. The metal support is preferably made of aluminum or an aluminum alloy, and the insulating coating applied to the metal support is preferably formed by alumite treatment. Furthermore, the insulating coating applied to the metal support may be a resin film, and the resin film is preferably made of Teflon resin or polyimide resin.

  In the first and second heaters of the present invention described above, the heating element is preferably formed by etching a metal foil.

  In the first and second heaters of the present invention described above, the metal support can be provided with a plurality of through holes. The heater having the plurality of through holes can be used as a gas shower substrate for a semiconductor manufacturing apparatus.

  According to the present invention, by forming an insulating coating on the heating element, it is basically unnecessary to use ceramics, and therefore it is possible to provide a heater that is very inexpensive and hardly damaged. The heater is extremely useful particularly as a gas shower substrate for a semiconductor manufacturing apparatus, and can preliminarily heat the gas introduced into the semiconductor manufacturing apparatus and simultaneously supply the gas to the semiconductor wafer.

  In the present invention, a structure (first heater) in which an insulating coated heating element is supported on a single metal support, or an insulating coated heating element is formed by two metal supports. (Second heater). In such a structure, since the main material constituting the heater is metal, it can be manufactured at a lower cost than ceramics, and a heater that is not easily damaged during processing, handling, and use can be provided.

  In the case of the first heater in which the heat generating body coated with insulation is supported by a single metal support, the number of components is small, and an inexpensive heater can be obtained with a very simple structure. Further, in the case of the second heater in which the insulating heating element is sandwiched between two metal supports, the number of parts increases as compared with the first heater, but the contact area between the heating element and the metal support is increased. Is larger than that of the first heater, so that the speed at which heat is diffused throughout the heater is increased, and the temperature can be quickly raised. As described above, since the first heater and the second heater have different characteristics depending on the structure, they can be selectively used according to the application.

The insulating coating formed on the heating element may be any material as long as it can prevent electrical leakage from the heating element to the metal support, and the material and formation method are not particularly limited. For example, an insulating coating can be formed on the heating element by thermal spraying. The material to be sprayed is not particularly limited as long as it is an insulating material, and for example, an insulating material such as Al ₂ O ₃ , SiO ₂ , mullite, or zirconia is preferably used. By uniformly spraying these materials on the heating element, insulation against the metal support can be ensured. Since the oxide sprayed film as described above generally has a high heat-resistant temperature, it is particularly suitable when a heater is used at a high temperature.

  In addition, a resin film can be used as the insulating coating of the heating element. As for the method of coating the resin on the heating element, any method may be used as long as insulation from the metal support can be secured. For example, there are a method in which a heating element is dipped in a resin solution, pulled up, dried and fired (cured), a method of applying by spraying, and a method of laminating a heating element with a sheet-like resin. Insulating coatings with these resin films are preferable in that they can be formed at a very low cost as compared with sprayed films of insulating materials such as oxides. However, since the heat-resistant temperature of the resin is generally lower than that of a sprayed film such as an oxide, it is desirable to use both in accordance with the application and purpose.

  The resin used for the insulation coating of the heating element is not particularly limited, but heat-resistant Teflon resin and polyimide resin are particularly suitable. Since these resins are stable even at temperatures of 200 ° C. or higher, the heater can be used up to a relatively high temperature.

  In the present invention, it is possible to apply an insulating coating to the metal support simultaneously with the insulating coating of the heating element. Insulating coating is also applied to the metal support, which is preferable because the insulation between the heating element and the metal support can be further ensured. In addition, when the electrode of the heating element, that is, the portion connected to the external power supply terminal exists in the vicinity of the metal support, the electrode of the heating element and the external power supply terminal must ensure insulation from the metal support. However, if an insulating coating is formed on the metal support, a structure for securing insulation at the connection portion between the electrode and the external power supply terminal is not required, and thus the connection structure with the external power supply terminal can be simplified. Particularly preferred in terms.

There is no particular limitation on the method for forming the insulating coating on the metal support. For example, the insulating coating can be formed by thermal spraying in the same manner as the insulating coating of the heating element described above. The material to be sprayed is not particularly limited as long as insulation can be ensured. For example, an insulating material such as Al ₂ O ₃ , SiO ₂ , mullite, zirconia, or the like can be used.

  When the metal support used is aluminum or an alloy containing aluminum, an insulating coating can be formed by subjecting the metal support to an alumite treatment. The alumite film is an aluminum oxide film, and can be easily formed by anodization of aluminum, and is particularly preferable because of its excellent insulating properties.

  Furthermore, a resin film can also be selected as the insulating coating formed on the metal support. As for the method of coating the resin on the metal support, any method may be used as long as the insulation from the heating element can be secured. For example, there are a method of immersing and lifting a metal support in a resin solution, and then drying and baking (curing), a method of applying by spraying, and a method of laminating a metal support with a sheet-like resin. Insulating coatings with these resins are preferable in that they can be formed at a very low cost as compared with sprayed films of insulating materials such as oxides. However, since the heat-resistant temperature of the resin is generally lower than that of a sprayed film such as an oxide, it is desirable to use both in accordance with the application and purpose.

  The resin used for the insulating coating of the metal support is not particularly limited, but heat-resistant Teflon resin and polyimide resin are particularly suitable. Since these resins are stable even at temperatures of 200 ° C. or higher, the heater can be used up to a relatively high temperature.

  The heating element used in the heater of the present invention is preferably a metal foil. In general, since the metal foil has a small thickness variation, when the heating element circuit pattern is formed, the resistance value variation can be suppressed small. As a method of forming the heating element circuit pattern, punching or etching can be used. In particular, etching is preferable because there is almost no restriction on the shape of the heating element circuit pattern.

  For this reason, by forming the heating element circuit pattern by etching the metal foil, a heating element having a relatively stable resistance value can be manufactured at low cost. Of course, since the heating element is a metal foil, there is no fear of breakage. The material of such a metal foil is not particularly limited as long as it can be etched. For example, it can be selected from various metal materials such as stainless steel, tungsten, molybdenum, and nichrome.

  The material of the metal support is not particularly limited, and stainless steel, aluminum, aluminum alloy, nickel, nickel alloy, or the like can be used. From these metal materials, it can select suitably according to the use temperature and use environment of a heater. For example, stainless steel, nickel, aluminum, and alloys thereof can be used when used in an oxidizing atmosphere, but stainless steel and nickel are preferred when used at a high temperature of 600 ° C. or higher.

  When the heater of the present invention is actually manufactured, the insulating coated heating element is supported by a metal support, but there is no particular limitation on the method. For example, in the case of the first heater, an insulatingly coated heating element can be integrated by being fixed with a resin or the like on the surface of one metal support. Further, in the case of the second heater, an insulating coated heating element is sandwiched between two metal supports and fixed in the same manner with resin, or mechanically fixed with rivets or screws. be able to.

  In the heater of the present invention, a plurality of through holes can be formed in a metal support that supports or sandwiches the heating element. The through hole is formed by penetrating the metal support at a position that avoids the heating element supported or sandwiched by the metal support. The number and shape of the through holes to be formed can be appropriately selected according to the application.

  A heater in which a plurality of through holes are formed in a metal support as described above can be used as a gas shower substrate for a semiconductor manufacturing apparatus. That is, when the gas is heated by supplying the gas to be introduced into the semiconductor manufacturing apparatus through the through hole of the gas shower substrate when the surface of the semiconductor wafer is subjected to etching treatment or film formation is performed. At the same time, the gas can be uniformly supplied to the semiconductor wafer.

  The operating temperature of the gas shower substrate at this time depends on the heat-resistant temperature of the material used for the heating element, the metal support, and the insulating coating. For example, when the heating element and the metal support are stainless steel, and the insulating coating of the heating element is an oxide sprayed film, the use temperature depends on the heat resistance temperature of the stainless steel. When the insulating coating of the heating element is a resin, the use temperature depends on the heat-resistant temperature of the resin, and is generally 300 ° C. or lower. Thus, it is necessary to select various materials used for the heater in accordance with the operating temperature and operating environment of the gas shower substrate.

[Example 1]
A stainless steel foil having a thickness of 50 μm was prepared, and this was subjected to an etching process on the heating element circuit pattern shown in FIG. Next, a Teflon (registered trademark) resin was applied to the heating element 1 by spraying except for the electrode 2 and then fired (cured) at 250 ° C. to form an insulating coating. The thickness of this insulating coating was 50 μm. In FIG. 1, reference numeral 3 denotes a metal support that supports the heating element 1.

  Also, two aluminum metal supports 3 having a thickness of 2 mm and a diameter of 330 mm were prepared. As shown in FIG. 2, a plurality of through holes 4 (illustrated by white circles) were formed on the two metal supports 3 while avoiding the heating element 1. In addition, fixing screw holes 5 (illustrated by black circles) were formed at four locations in order to sandwich and integrate the heating element 1. Furthermore, one of the metal supports 3 was provided with an electrode connection screw hole 6 for attaching an external power supply terminal at a position corresponding to the electrode 2 of the heating element 1.

Next, the insulation-coated heating element 1 was sandwiched between two aluminum metal supports 3 and fixed with four fixing screw holes 5. Further, on both sides of the electrode 2 of the heating element 1, an Al ₂ O ₃ plate having a thickness of 3 mm and a diameter of 6 mm and having a screw hole formed in the center portion is applied to connect the electrodes provided on one metal support 3. An external power supply terminal was inserted into the screw hole 6 and fixed with an aluminum screw. In this manner, a heater used as a gas shower substrate for a semiconductor manufacturing apparatus was produced.

  This gas shower substrate was mounted on an actual single wafer type semiconductor manufacturing apparatus. As a result, when the passing gas was atmospheric, nitrogen, or argon, it could be used up to 250 ° C. without any problem. At this time, the time required for the gas shower substrate (heater) to reach 250 ° C. was 10 minutes.

Next, a heater having the same structure was produced using the same material as described above. However, as the metal support, an aluminum plate in which the entire surface was anodized after a plurality of through holes and screw holes were formed in the aluminum plate was used. As a result, it is no longer necessary to use an Al ₂ O ₃ plate as described above in order to insulate the heating element from the electrodes. When this heater was mounted on a semiconductor manufacturing apparatus as a gas shower substrate, it could be used without problems up to 250 ° C., and the time for the heater to reach 250 ° C. was 10 minutes.

[Example 2]
A stainless steel foil having a thickness of 50 μm was prepared, and this was subjected to an etching process on the heating element circuit pattern shown in FIG. 1 to form a heating element. This heating element was immersed in a polyimide solution except for the electrodes, taken out, and then fired (cured) in the air at 350 ° C. to form an insulating coating of polyimide resin. In addition, the same aluminum metal support as in Example 1 was prepared.

  Next, this insulatingly coated heating element was bonded and fixed to an aluminum metal support with an epoxy resin to form a gas shower substrate (heater). As a result of mounting this gas shower substrate on a semiconductor manufacturing apparatus, it could be used up to 250 ° C. without any problem. Moreover, the time for the heater to reach 250 ° C. was 18 minutes, and a tendency to be slightly slower than in the case of Example 1 appeared.

[Example 3]
A molybdenum foil having a thickness of 50 μm was prepared, and this was etched into the heating element circuit pattern shown in FIG. 1 to form a heating element. On the surface of this heating element, an insulating coating of Al ₂ O ₃ was formed by thermal spraying except for the electrodes. Further, two stainless steel plates having a thickness of 2 mm and a diameter of 330 mm were prepared, and an insulating coating of Al ₂ O ₃ was also formed thereon by thermal spraying. Thereafter, as shown in FIG. 2, a plurality of through holes and screw holes were formed to form a metal support.

  Next, the heating element was sandwiched between the two metal supports, fixed with stainless steel screws, and the electrodes were connected in the same manner as in Example 1 to complete the heater. This heater could be used without problems up to 750 ° C. even when an oxidizing gas was used as the gas shower substrate. Also, it could be used sufficiently up to 500 ° C. against corrosive gases such as fluoride.

[Example 4]
A 70 μm-thick nichrome foil was prepared, and this was etched into the heating element circuit pattern shown in FIG. 1 to produce a heating element. The heating element was immersed in a polyimide solution except for the electrodes, pulled up, and then fired (cured) in the air at 350 ° C. to form an insulating coating of polyimide resin. Also, two nickel plates with a thickness of 2 mm and a diameter of 330 mm are prepared, and a plurality of through holes and screw holes are formed as shown in FIG. 2, and further immersed in a polyimide solution and pulled up, and then fired at 350 ° C. in the atmosphere. (Cure) to obtain a metal support having an insulating coating of polyimide resin.

  Next, the heating element was sandwiched between the two metal supports, fixed with nickel screws, and electrodes were connected in the same manner as in Example 1 to produce a heater. As a result of mounting this heater as a gas shower substrate in a single wafer type semiconductor manufacturing apparatus, it was possible to use the heater up to 300 ° C. without any problem.

[Comparative example]
The nichrome foil used in Example 4 was etched into the heating element circuit pattern shown in FIG. 1 to obtain a heating element. In addition, _two Al ₂ O ₃ plates having a thickness of 2 mm and a diameter of 330 mm were prepared as metal supports and processed into the shape shown in FIG. Since this Al ₂ O ₃ metal support plate is an insulator, a nichrome foil heating element was sandwiched as it was, and a heater was produced in the same manner as in Example 1.

This heater was mounted on a single wafer type semiconductor manufacturing apparatus as a gas shower substrate, and the temperature was raised to 250 ° C. The temperature raising time required at this time was 10 minutes. After the temperature was raised to 250 ° C., the heater was taken out, cracks were generated so as to connect a plurality of through holes formed in the Al ₂ O ₃ metal support, and the heater was damaged.

It is a top view which shows the heat generating body of the heater concerning this invention. It is a top view which shows the metal support body of the heater concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat generating body 2 Electrode 3 Metal support 4 Through-hole 5 Fixing screw hole 6 Electrode connection screw hole

Claims (13)

  A heater comprising: a heat generating body coated with insulation; and a metal support having the heat generating body supported and fixed on the surface.   A heater comprising: a heat generating body covered with insulation; and two metal support bodies sandwiched and fixed on both sides of the heat generating body.   The heater according to claim 1 or 2, wherein the insulating coating applied to the heating element is a sprayed film.   The heater according to claim 1 or 2, wherein the insulating coating applied to the heating element is a resin film.   The heater according to claim 4, wherein the resin film is made of Teflon resin or polyimide resin.   The heater according to any one of claims 1 to 5, wherein the metallic support is covered with an insulating coating.   The heater according to claim 6, wherein the insulating coating applied to the metal support is a sprayed film.   The heater according to claim 6, wherein the metal support is made of aluminum or an aluminum alloy, and the insulating coating applied to the metal support is formed by an alumite treatment.   The heater according to claim 6, wherein the insulating coating applied to the metal support is a resin film.   The heater according to claim 9, wherein the resin film is made of Teflon resin or polyimide resin.   The heater according to any one of claims 1 to 10, wherein the heating element is formed by etching a metal foil.   The heater according to claim 1, wherein the metal support has a plurality of through holes.   The heater according to claim 12, wherein the heater is used as a gas shower substrate for a semiconductor manufacturing apparatus.

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