JP3953021B2 - heater - Google Patents

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 for 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, silicon nitride, alumina, sialon, a resistance heating element in a ceramic such as aluminum nitride formed by using the gas supply member having a plurality of gas inlet holes, liquid at room temperature such as TiCl ₄ When introducing the gas containing the material into the film forming apparatus, TiCl _{4 and the} like are prevented from condensing, and the film can be stably formed and cleaned on the wafer.

  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 a heating element on the surface of an insulating coated metal support or sandwiching between two insulating coated metal supports. To do. With such a structure, it is not necessary to use ceramics at all, and it can be manufactured at low cost, and further, a heater that is not easily damaged can be obtained.

  In other words, the first heater provided by the present invention is characterized by comprising a metal support that is insulated and a heating element that is supported and fixed on the surface of the metal support. Further, the second heater provided by the present invention includes two metal supports that are insulated and a heating element that is fixed by sandwiching both surfaces between the two metal supports. It is characterized by.

  In the first and second heaters of the present invention described above, 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. . Further, it is more preferable that the insulating coating applied to the metal support is a resin film further formed after anodizing.

  In the first and second heaters of the present invention, the insulating coating applied to the metal support may be a sprayed film. Alternatively, 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 may be covered with insulation. 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 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, it is not necessary to use ceramics basically by forming an insulating coating on a metal support, 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) for supporting a heating element on one insulating-coated metal support is used, or between two insulating-coated metal supports. A structure (second heater) that sandwiches the heating element is adopted. In such a structure, since the main material constituting the heater is metal, it can be manufactured at a lower cost than a conventional heater made of ceramics, and it is damaged during processing, handling and use. A difficult heater can be provided.

  In the case of the first heater supported by a single metal support with an insulating coating on the heating element, the number of parts constituting the heater is small, and an inexpensive heater can be obtained with a very simple configuration. In addition, in the case of the second heater sandwiched between two metal supports with insulation coating on the heating element, the contact area between the heating element and the metal support is larger than that of the first heater, so that the entire heater is There is an advantage that the rate of heat diffusion becomes relatively fast and the temperature can be raised quickly. 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 metal support is not particularly limited as long as it can prevent electrical leakage from the heating element to the metal support. For example, 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 anodized film is an aluminum oxide film, and is particularly preferable because it is formed by anodization of aluminum and has excellent insulating properties.

  In addition to the above-described alumite treatment, an insulating coating with a resin film can be further applied. In this case, since the thickness of the insulating coating can be relatively increased, the voltage applied to the heater can be increased, and the temperature rise rate can be further increased, which is preferable. However, since resin is used for a part of the insulating coating, the heat-resistant temperature as a heater is lower than in the case of anodizing alone. For this reason, only alumite treatment is used when used at high temperatures, and when a low temperature and rapid temperature increase are required, a resin film is further coated on the alumite treatment film, depending on the application and purpose of the heater. That's fine.

Further, an insulating coating can be formed on the metal support by thermal spraying. The material to be sprayed is not particularly limited as long as it is an insulating material. For example, it is preferable to use an insulating material such as Al ₂ O ₃ , SiO ₂ , mullite, or zirconia. By providing the thermal spray film of these insulating materials uniformly on the metal support, it is possible to ensure insulation with respect to the heating element. The sprayed film at this time may be formed on the entire surface of the metal support, but it may be functionally formed only at least on the portion where the heating element is installed. Since the sprayed film generally has a relatively high heat resistant temperature, it is particularly suitable when a heater is used at a high temperature.

  Furthermore, a resin film can also be selected as the insulating coating formed on the metal support. As a method for coating the resin film, any method can be used as long as the insulation with the heating element can be ensured as described above. For example, there are a method of immersing a metal support in a resin solution, pulling it up, drying and baking (curing), a method of applying by spraying, and a method of laminating a sheet-like resin on a metal support. . Insulating coatings with these resins are preferable in that they can be formed at a very low cost compared to thermal spraying.

  The resin used for the insulating coating of the metal support is not particularly limited, but it is particularly preferable to use a heat-resistant Teflon resin or polyimide resin. 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 heat generating element at the same time as the insulating coating of the metal support. It is preferable to insulate the heating element because insulation between the metal support and the heating element can be further ensured. However, since the heating element needs to supply electric power from the outside, the electrode provided at the end of the heating element and the portion that electrically connects the electrode and the external power supply terminal are naturally provided with an insulating coating. Must not exist.

There is no particular limitation on the method for forming the insulating coating on the heating element. For example, the insulating coating can be formed by thermal spraying as in the case of the insulating coating on the metal support 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.

  A resin film can also be selected as the insulating film formed on the heating element. As for the method of coating the heat generating body with the resin film, 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 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. Even in the case of an insulating coating made of resin, an insulating coating must not be formed on the electrode of the heating element and the portion where the electrode and the external power supply terminal are electrically connected.

  The resin used for the insulation coating of the heating element is not particularly limited, but it is particularly preferable to use a heat-resistant Teflon resin or polyimide resin. 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 heating element is supported by a metal support that is coated with insulation, but there is no particular limitation on the method. For example, in the case of the first heater, the heating element can be fixed and integrated with a resin or the like on the surface of a single insulating-coated metal support. In the case of the second heater, a heating element is sandwiched between two insulating coated metal supports, and similarly fixed 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. 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, Teflon (registered trademark) resin was applied to the aluminum metal support 3 by spraying, and then fired in the atmosphere at 250 ° C. to form an insulating coating. At this time, the thickness of the insulating coating made of Teflon resin was 50 μm.

  The stainless steel foil heating element 1 was sandwiched between two aluminum metal supports 3 provided with an insulating coating, and fixed with four fixing screw holes 5. Further, an external power supply terminal was inserted into the electrode connection screw hole 6 provided in one metal support 3 and screwed 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, an insulating coating made of Teflon resin was formed on the heating element by the same method as above except for 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]
Next, the same heating element as in Example 1 and an aluminum metal support were prepared, and an insulating coating of polyimide resin was formed on the metal support in the same manner as in Example 1. . A heater was prepared by fixing a heating element with an epoxy resin on the single metal support.

  As a result of mounting this heater as a gas shower substrate in 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 slightly slower than the above 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 the 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 a plurality of through holes and screw holes were formed as shown in FIG. 2 to obtain a metal support. Also on this metal support, an insulating coating of Al ₂ O ₃ was formed by thermal spraying similarly to the heating element.

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

[Example 4]
A tungsten foil having a thickness of 100 μm was prepared, and this was etched into the heating element circuit pattern shown in FIG. 1 to form a heating element. Further, two stainless steel plates having a thickness of 2 mm and a diameter of 330 mm were prepared, and a plurality of through holes and screw holes were formed as shown in FIG. 2 to obtain a metal support. An insulating coating of Al ₂ O ₃ was formed on the metal support by thermal spraying.

  Next, the heating element was fixed between two metal supports with stainless steel screws, and electrodes were connected in the same manner as in Example 1 to complete the heater. This heater could be used as a gas shower substrate with no problem up to 750 ° C. against non-oxidizing gases such as nitrogen and argon. However, for an oxidizing gas such as air, a blue oxide film was formed on the surface of the tungsten foil as a heating element when the temperature exceeded 350 ° C.

[Example 5]
A 70 μm thick nichrome foil was prepared, and this was etched into the heating element circuit pattern shown in FIG. 1 to form a heating element. Further, two nickel plates having a thickness of 2 mm and a diameter of 330 mm were prepared, and a plurality of through holes and screw holes were formed as shown in FIG. This metal support was immersed in a polyimide solution, pulled up, and then fired in the air at 350 ° C. to form an insulating coating.

  Next, the heating element was fixed between two metal supports with a nickel screw, and electrodes were connected in the same manner as in Example 1 to complete the heater. This heater was used as a gas shower substrate in a single wafer type semiconductor manufacturing apparatus, and as a result, could be used without problems up to 300 ° C.

[Example 6]
The same aluminum metal support as in Example 1 was prepared. After processing the metal support into the shape shown in FIG. 2 in the same manner as in Example 1, the surface was subjected to anodizing to provide an insulating coating. Formed. A heater made by etching the same stainless steel foil as in Example 1 was sandwiched between two metal supports on which an insulating coating was formed by anodizing, and a heater was manufactured by screwing.

As in Example 1, this heater was incorporated in a semiconductor manufacturing apparatus as a gas shower substrate, and air, nitrogen, argon, and CF ₄ were used as the flowing gas. As a result, the heater could be used without problems up to 500 ° C. At this time, the heating time of the heater up to 250 ° C. was 15 minutes.

  Next, the same alumite-treated aluminum metal support as described above was further coated with a Teflon resin. A heater was prepared in the same manner as above except that this metal support was used, and it was incorporated into a semiconductor manufacturing apparatus as a gas shower substrate. It was possible to raise the temperature.

  Further, after the same alumite treatment as described above, a heater was manufactured in the same manner as above except that an aluminum metal support coated with Teflon resin and a stainless steel heating element coated with Teflon resin were used. did. As a result of incorporating this heater as a gas shower substrate in a semiconductor manufacturing apparatus, it was possible to use the heater up to 250 ° C. against the atmosphere, nitrogen, and argon, and to raise the temperature in 6 minutes.

[Comparative example]
The nichrome foil used in Example 5 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 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 (11)

An insulating coated metal support and a heating element fixed by sandwiching both surfaces between the two metal supports, the metal support having a plurality of through holes, and a semiconductor A heater characterized by being used as a gas shower substrate for a manufacturing apparatus . The heater according to claim 1 , 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 2 , wherein the insulating coating applied to the metal support is a resin film further formed after anodizing . The heater according to claim 1 , wherein the insulating coating applied to the metal support is a sprayed film . The heater according to claim 1 , wherein the insulating coating applied to the metal support is a resin film . The heater according to claim 5 , wherein the resin film is made of Teflon resin or polyimide resin . The heater according to any one of claims 1 to 6, wherein the heating element is coated with insulation . The heater according to claim 7 , wherein the insulating coating applied to the heating element is an oxide sprayed film . The heater according to claim 7 , wherein the insulating coating applied to the heating element 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 .

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