Heat shield member and substrate processing apparatus

Abstract

To provide a heat shield member that can effectively shield heat, and to provide a substrate processing apparatus using the same.SOLUTION: A heat shield member for shielding heat includes a spiral part formed by spirally winding a plate-like body so as to be laminated into a plurality of layers while surfaces of the plate-like body are spaced apart. The heat shield member is used for such applications as shielding radiation heat of a high-temperature heating type stage on which a substrate is placed in a substrate processing apparatus.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a heat shielding member and a substrate processing apparatus.

Background Art

[0002] Patent Document 1 discloses a substrate processing apparatus provided with a heat shield for shielding heat from a shower head outside a wafer placement area of a placement table on which a substrate heated by a lamp is placed, and a laminated structure is described as the heat shield. Further, Patent Document 2 describes that in a single crystal manufacturing apparatus for epitaxially growing a single crystal on a substrate by a CVD method, a heat insulating material is provided on a placement surface on which the substrate is placed to suppress heating of the substrate due to heat conduction from a susceptor to the substrate. It is described that the heat insulating material may have a laminated structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a heat shielding member capable of effectively shielding heat and a substrate processing apparatus using the same.

Means for Solving the Problems

[0005] A heat shielding member according to an aspect of the present disclosure is a heat shielding member that shields heat, and includes a spiral portion formed by spirally winding a plate-like body so that the surfaces of the plate-like body overlap in a plurality of layers with a gap therebetween.

Effects of the Invention

[0006] According to the present disclosure, there are provided a heat shielding member capable of effectively shielding heat and a substrate processing apparatus using the same.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0009] <Heat Shielding Member> FIG. 1 is a perspective view showing an example of a heat shielding member according to an embodiment, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is a perspective view schematically showing a spiral portion included in a heat shielding member according to an embodiment.

[0010] The heat shielding member 1 in this example shields (insulates) heat and has an overall annular shape as shown in FIG. 1. The heat shielding member 1 includes a first flat plate 2 and a second flat plate 3 that form an annulus, and a spiral portion 4. The spiral portion 4 is sandwiched between the first flat plate 2 and the second flat plate 3. The overall diameter and thickness of the heat shielding member 1 are appropriately set according to the size and temperature of the heat source to be shielded, the temperature to be reduced, and the like.

[0011] The first flat plate 2 and the second flat plate 3 may be formed of a metal material with a low emissivity in order to reduce the amount of heat radiation. As the metal material, an appropriate one may be used according to the temperature and environment, but Ni or Ni alloy with high heat resistance and corrosion resistance can be preferably used. Depending on the temperature and environment, aluminum (Al), Al alloy, or stainless steel can also be used. When the operating temperature is 700 °C or higher, ceramics such as zirconia (ZrO2) with a high emissivity but higher heat resistance and corrosion resistance than Ni or Ni alloy are suitable. The thickness of the first flat plate 2 and the second flat plate 3 may be 1 to 3 mm.

[0012] As schematically shown in FIG. 3, the spiral portion 4 is formed by spirally winding a plate-like body so that its surfaces overlap in a plurality of layers with intervals therebetween, and functions as a main element for heat shielding. Similar to the first flat plate 2 and the second flat plate 3, the spiral portion 4 may be formed of a metal material with a low emissivity in order to reduce the amount of heat radiation. As the metal material, Ni or Ni alloy with high heat resistance and corrosion resistance can be preferably used, but depending on the temperature and environment, it may also be Al, Al alloy, or stainless steel. Further, it may be a composite of a plurality of metals. In addition to the metal material, the spiral portion 4 may be ceramics such as ZrO2, or a composite of metal and ceramics, for example, a composite of Ni and ZrO2. The spiral portion 4 may be selected from the above materials according to the operating temperature and environment.

[0013] In the case of applications for shielding radiant heat from high-temperature members, it is advantageous for the entire heat shielding member 1 to be composed of a metal material with a low emissivity. Among them, Ni or Ni alloy with good heat resistance and corrosion resistance is advantageous.

[0014] The thickness of the plate-like body constituting the spiral portion 4 and the pitch of winding are arbitrary, but the thickness of the plate-like body may be 1 to 3 mm and the pitch may be 3 to 9 mm.

[0015] The spiral portion 4 may be a laminated molded body. By using laminated molding, it can be manufactured more simply than in the case of processing from a plate material. Further, by using laminated molding, a composite body of metal and ceramics can be easily manufactured. Laminated molding is a process in which, based on digital data such as three-dimensional CAD of a product, original data obtained by thinly slicing the product is created, and thin layers of a desired material are sequentially laminated based on the original data. Typically, a 3D printer is used. As a method of laminated molding, for example, a method can be used in which while supplying a material powder, it is melted with a laser to form a thin layer and sequentially laminated.

[0016] The use of the heat shielding member 1 is not particularly limited. For example, it can be used for the purpose of shielding (heat insulating) radiant heat from a high-temperature portion in a chamber maintained in a vacuum atmosphere in a substrate processing apparatus such as a film forming apparatus. Specifically, it is used for the purpose of shielding radiant heat from a high-temperature heating stage on which a substrate is placed in a single-wafer film forming apparatus or a batch film forming apparatus. FIG. 1 shows an example of shielding radiant heat from above. Such a heat shielding member 1 has high heat shielding properties and can increase the amount of temperature drop (temperature gradient) on the opposite side with respect to the temperature on the incident side of radiant heat.

[0017] The heat shielding member itself has been conventionally known as described in Patent Documents 1 and 2, and has also been used for the purpose of shielding radiant heat in a film forming apparatus. However, in such a film forming apparatus, since the substrate is heated to a high temperature of several hundred degrees Celsius or 1000 °C or higher in the case of a batch type, the thermal energy of the radiant heat is high. For this reason, conventionally, as shown in FIG. 4, a method has been taken to gradually attenuate the radiant heat by using a heat shielding member 10 having a structure in which a plurality of heat shielding plates 11 are stacked. However, in the case of this technique, it is essential to support the plurality of heat shielding plates 11 by the support columns 12, and heat transfer (heat conduction) occurs between the heat shielding plates 11 through the support columns 12, thereby reducing the heat shielding effect. For this reason, in order to obtain a desired heat shielding effect with the conventional heat shielding member 10, measures such as increasing the number of heat shielding plates 11 are required, resulting in demerits such as an increase in material cost. Further, since heat is conducted from the support columns 12, the vicinity of the support columns 12 becomes a cold spot. For this reason, when the conventional heat shielding member 10 is disposed under a high-temperature heating type stage, there is a concern that the heat uniformity of the stage deteriorates due to the influence of the cold spot.

[0018] On the other hand, the heat shielding member 1 of the present embodiment has a spiral portion 4 formed by spirally winding a plate-like body so that a plurality of layers overlap with a gap therebetween, and thus no support column is required. For this reason, heat conduction by the support column is eliminated, and heat transfer between the respective layers of the spiral portion 4 is limited almost to radiant heat transfer. Strictly speaking, heat is transferred spirally to the lower layer along the plate-like body constituting the spiral portion 4, but the heat transfer distance is longer compared to the case where there is a support column. For this reason, according to Fourier's law expressed by the following formula (1), it is possible to suppress a decrease in the thermal gradient (temperature gradient) ΔT due to heat conduction (increase the thermal gradient ΔT) compared to the case where there is a support column. That is, by using the spiral portion 4, it is possible to suppress a decrease in the heat shielding effect due to heat conduction compared to the case where there is a support column. q=-k(ΔT / x) ···(1) (However, q: heat flux, k: thermal conductivity, x: heat transfer distance.)

[0019] In addition, by using the spiral portion 4, connection portions exist in each layer, and the heat shielding area becomes larger than that of a structure in which heat shielding plates are stacked, and the heat shielding effect can be enhanced accordingly.

[0020] As described above, since the heat shielding member 1 of the present embodiment has a greater heat shielding effect than the case where a plurality of heat shielding plates are stacked, the thickness can be made smaller than before, and space saving can be achieved. In addition, since there are no support columns in the heat shielding member 1 of the present embodiment, problems with temperature uniformity due to cold spots do not occur.

[0021] <Application Example of Heat Shielding Member> Next, an application example of the heat shielding member according to one embodiment will be described. FIG. 5 is a cross-sectional view showing a substrate processing apparatus to which a heat shielding member according to one embodiment is applied. As shown in FIG. 5, the substrate processing apparatus 100 performs, for example, a film forming process on a substrate W, and has a substantially cylindrical metal chamber (processing container) 101.

[0022] An exhaust port 102 is formed in the bottom wall of the chamber 101, an exhaust pipe 103 is connected to the exhaust port 102, and an exhaust mechanism 104 having a vacuum pump, a pressure control valve, etc. is connected to the exhaust pipe 103. By operating the exhaust mechanism 104, the inside of the chamber 101 can be set to a predetermined reduced pressure (vacuum) state. An opening 105 for loading and unloading the substrate is formed in the side wall of the chamber 101, and a gate valve 106 for opening and closing the opening 105 is provided.

[0023] Inside the chamber 101, a high-temperature heating type stage 107 for placing and heating the substrate W is horizontally provided. The stage 107 is formed of, for example, ceramics, and a heating heater (not shown) is embedded therein. The stage 107 is heated to a high temperature, for example, about 400 to 700°C by this heating heater, and is configured to heat the substrate W by the heat.

[0024] The stage 107 is fixedly attached to the upper end of a vertically extending metal support column 108. This support column 108 penetrates the bottom of the chamber 101 and extends downward, being supported by a base 109. And, it is configured such that the stage 107 is moved up and down between a conveyance position corresponding to the opening 105 and a processing position above it via the support column 108 by an actuator (not shown). A telescopic metal bellows 110 is provided in the through-hole where the support column 108 penetrates the bottom of the chamber 101, enabling the stage 107 to move up and down while maintaining the airtightness inside the chamber 101.

[0025] A shower head 111 is provided above the chamber 101 so as to face the stage 107. A gas supply pipe 112 extending from a gas supply section (not shown) is connected to the shower head 111, and the gas supplied from the gas supply section to the shower head 111 via the gas supply pipe 112 is configured to be introduced into the chamber 101 from the shower head 111 in a shower-like manner. As the gas, a processing gas, for example, a raw material gas or a reaction gas necessary for film formation, and further a purge gas, etc. are used. By supplying these processing gases from the shower head 111, film formation such as ALD or CVD is performed on the substrate W.

[0026] Heaters 113 for heating are provided on the side wall and the top wall of the chamber 101 so that liquefaction or solidification of the raw material gas supplied into the chamber 101 does not occur.

[0027] A heat shield member 120 having an overall annular shape is provided directly below the stage 107 inside the chamber 101. Similar to the above-described heat shield member 1, the heat shield member 120 has a first flat plate 121 and a second flat plate 122 having an annular shape, and a spiral portion 123, and the spiral portion 123 is sandwiched between the upper first flat plate 121 and the lower second flat plate 122. The heat shield member 120 is supported by attaching the first flat plate 121 to a support jig 114 extending upward from the base 109.

[0028] When the substrate processing apparatus 100 performs, for example, a film forming process on the substrate W, as the materials of the first flat plate 121, the second flat plate 122, and the spiral portion 123 of the heat shielding member 120, materials having a low emissivity and heat resistance and corrosion resistance, such as Ni or Ni alloys, are suitable.

[0029] In the substrate processing apparatus 100 configured as described above, with the high-temperature heating stage 107 set to a predetermined temperature in the range of, for example, 400 to 700°C, the substrate W conveyed into the chamber 101 is placed on the stage 107. Then, after evacuating the inside of the chamber 101 and setting it to a desired vacuum pressure, as a processing gas from the shower head, for example, a raw material gas or a reaction gas is supplied sequentially or simultaneously to form a desired film on the substrate W.

[0030] At this time, since the stage 107 is in a high-temperature state, the heat shielding member 120 shields the radiant heat from the stage 107 so as not to be affected by the radiant heat below the stage 107. Specifically, the radiant heat of the stage 107 is attenuated step by step by the first flat plate 121, the plurality of layers of the spiral portion 123, and the second flat plate 122. Thereby, the energy of the radiant heat from the stage 107 is reduced, and the temperature on the output side of the heat shielding member 120 can be sufficiently lowered compared to the temperature on the input side.

[0031] <Simulation Results> Next, the simulation results showing the effects of the heat shielding member of one embodiment will be described. Here, as shown in FIG. 6, a simulation was performed using a model in which an annular heat shielding member having an emissivity of 0.1 (simulating Ni) was disposed between a dummy stage having a temperature of 400°C and an emissivity of 0.9 and a dummy chamber having a temperature of 250°C and an emissivity of 0.1.

[0032] As models of the heat shielding member, Case 1 with a conventional structure and Case 2 with the structure of the above embodiment were used. As shown in Fig. 7, Case 1 stacked five plates with a thickness of 1 mm at a pitch of 3 mm, supported by three metal support columns with a diameter of φ5 mm, and had an overall thickness of 13 mm. As shown in Fig. 8, Case 2 sandwiched a spiral portion formed by winding a plate with a thickness of 1 mm at a pitch of 3 mm spirally with a plate with a thickness of 1 mm, and also had an overall thickness of 13 mm.

[0033] Note that the simulation was performed assuming a vacuum environment (0 Pa) without the influence of convection and without heat conduction between the plates.

[0034] The simulation results of Case 1 and Case 2 are shown in Fig. 9 and Fig. 10 respectively. As shown in Fig. 9, in the case of Case 1, the temperature of the upper surface was 361.26 °C, the temperature of the lower surface was 312.36 °C, and ΔT was 49 °C. On the other hand, in the case of Case 2, the temperature of the upper surface was 361.62 °C, the temperature of the lower surface was 261.76 °C, and ΔT was 100 °C. From this result, it was confirmed that the heat shielding member with the structure of the above embodiment has a higher heat shielding (heat insulation) effect. Also, in the case of Case 1, as shown in Fig. 9, there was a cold spot around the support column, and the in-plane temperature uniformity was low. In contrast, in the case of Case 2, as shown in Fig. 10, it was confirmed that such non-uniformity was not observed.

[0035] Note that although it is not physically possible, the simulation was also performed in the same manner for the structure obtained by removing the support column from Case 1. As a result, the temperature of the upper surface was similar to that of Case 1, ΔT was 89 °C, and ΔT was smaller than that of Case 2. This is considered to be because there is a connecting portion of the plates in Case 2, and the area of the plates contributing to heat shielding is larger in Case 2.

[0036] <Other applications> Although the embodiments have been described above, it should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and gist of the appended claims.

[0037] For example, in the above embodiment, a heat shielding member having a configuration in which a spiral portion is sandwiched between a first flat plate and a second flat plate was exemplified. However, the first flat plate and the second flat plate are not essential, and it is sufficient that the heat shielding member has a spiral portion. Further, the number of layers (number of turns), pitch, and thickness of the plate-like body of the spiral portion are not limited to those of the above embodiment, and may be appropriately set according to the required ΔT and the size of the chamber.

[0038] In the above embodiment, the case where the heat shielding member is applied to a film forming apparatus was exemplified. However, it is also applicable to a substrate processing apparatus accompanied by heating other than a film forming apparatus. Further, in the above embodiment, an example in which the heat shielding member is provided below a high-temperature heating type stage in a chamber to shield radiant heat from the stage was shown. However, the present invention is not limited to this, and it can be used for applications of shielding radiant heat from a high-temperature member in a chamber. Furthermore, not limited to shielding radiant heat, it can also be used for applications of shielding (heat insulating) heat to suppress a temperature drop due to heat dissipation from members in a chamber. For example, the heat shielding member can be disposed between the shower head 111 and the lid of the chamber 101 of the substrate processing apparatus in FIG. 5 to shield (heat insulate) between them, and can be used for applications of suppressing a temperature drop of the shower head 111.

[0039] Furthermore, in the above embodiment, an example in which the heat shielding member is disposed in the chamber of the substrate processing apparatus was shown. However, the present invention is not limited to this, and it can be used for all applications of heat shielding (heat insulating).

Explanation of Reference Numerals

[0040] 1, 120; Heat shielding member 2, 121; First flat plate 3, 122; Second flat plate 4, 123; Spiral portion 100; Substrate processing apparatus 101; Chamber (processing container) 107; High-temperature heating type stage 111; Shower head W; Substrate

Claims

1. A heat shielding member for shielding heat, comprising a spiral portion formed by spirally winding a plate-like body such that the surfaces of the plate-like body overlap in a plurality of layers with a gap therebetween.

2. The heat shielding member according to claim 1, further comprising a first flat plate and a second flat plate provided so as to sandwich the spiral portion.

3. The heat shielding member according to claim 2, wherein the spiral portion, the first flat plate, and the second flat plate are made of a metal material.

4. The heat shielding member according to claim 3, wherein the spiral portion, the first flat plate, and the second flat plate are made of nickel or a nickel alloy.

5. The heat shielding member according to claim 1, wherein the spiral portion is made of a metal material, a ceramic material, or a composite material of metal and ceramic.

6. The heat shielding member according to claim 5, wherein the spiral portion is made of nickel or a nickel alloy, zirconia, or a composite material of nickel and zirconia.

7. The heat shielding member according to claim 1, which is used for heat shielding in a vacuum atmosphere.

8. The heat shielding member according to any one of claims 1 to 7, wherein the spiral portion is a laminated structure.

9. A substrate processing apparatus for processing a substrate, comprising a processing container for accommodating the substrate and holding it in a vacuum, a member provided in the processing container, and a heat shielding member for shielding heat from the member, wherein the heat shielding member comprises a spiral portion formed by spirally winding a plate-like body such that the surfaces of the plate-like body overlap in a plurality of layers with a gap therebetween.

10. The member is a high-temperature member, and the heat shielding member shields radiant heat from the high-temperature member. The substrate processing apparatus according to claim 9.

11. The substrate processing apparatus is a film forming apparatus having, as the member, a high-temperature heating stage on which the substrate is placed and a shower head for supplying a film forming gas into the processing container. The heat shielding member is disposed below the stage and shields radiant heat from the stage. The substrate processing apparatus according to claim 9.

12. The substrate processing apparatus is a film forming apparatus having, as the member, a high-temperature heating stage on which the substrate is placed and a shower head for supplying a film forming gas into the processing container. The heat shielding member is provided between the processing container and the shower head and suppresses a temperature drop of the shower head. The substrate processing apparatus according to claim 9. ​

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