Wafer holding table and semiconductor processing apparatus

Abstract

To provide a wafer holding table capable of reducing power consumption of a semiconductor processing apparatus.SOLUTION: A wafer holding table disposed in a chamber, the wafer holding table comprising: a placement plate having an upper surface on which a wafer is placed and a lower surface opposite to the upper surface; a support that supports the lower surface; and a first reflection plate that faces a portion of the lower surface that is not covered with the support, wherein a length L1 between the lower surface and an upper surface of the first reflection plate is 0. 1mm or more and 60mm or less, and a radiation rate of the first reflection plate is equal to or less than a radiation rate of the placement plate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a wafer holder and a semiconductor processing apparatus. This application claims priority from international application PCT / JP2023 / 022163, filed June 14, 2023, and incorporates by reference all of the contents of said international application. [Background technology]

[0002] Patent Documents 1 and 2 disclose techniques related to a wafer holder placed within a chamber. The wafer holder has an upper surface on which a wafer is placed. A semiconductor processing apparatus in which a wafer holder is placed within a chamber is, for example, a film deposition apparatus that forms a coating on the surface of a wafer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-505551 [Patent Document 2] Japanese Patent Application Publication No. 2020-155519 Summary of the Invention [Problem to be solved by the invention]

[0004] In semiconductor processing equipment, wafers must be maintained at a predetermined temperature or higher. A heater is installed inside the wafer holder, and the wafer temperature is maintained by raising the temperature of the wafer holder. However, because the heat from the wafer holder is dissipated into the chamber and then from the chamber to the outside, a large amount of power is consumed to maintain a constant temperature of the wafer holder.

[0005] An object of the present disclosure is to provide a wafer holder that can reduce the amount of power consumed by a semiconductor processing apparatus. [Means for solving the problem]

[0006] The wafer holder of the present disclosure is a wafer holder placed within a chamber, and includes a mounting plate having an upper surface on which a wafer is placed and a lower surface opposite the upper surface, a support body supporting the lower surface, and a first reflector facing a portion of the lower surface not covered by the support body, wherein the distance L1 between the lower surface and the upper surface of the first reflector is 0.1 mm or more and 60 mm or less, and the emissivity of the first reflector is equal to or less than the emissivity of the mounting plate. [Effects of the Invention]

[0007] The wafer holder of the present disclosure can reduce the power consumption of the semiconductor processing apparatus by using the first reflector provided on the wafer holder. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a semiconductor processing apparatus equipped with a wafer holder according to the first embodiment. [Figure 2] FIG. 2 is an enlarged half cross-sectional view of the upper portion of the semiconductor processing apparatus shown in FIG. [Figure 3] FIG. 3 is an enlarged half cross-sectional view of an upper portion of a wafer holder provided with a plurality of first reflectors. [Figure 4] FIG. 4 is a half cross-sectional view of the upper part of the semiconductor processing apparatus further including an outer wall portion in addition to the configuration of FIG. [Figure 5] FIG. 5 is a cross-sectional view of a wafer holder including a first reflector having an outer wall portion and an inner wall portion. [Figure 6] FIG. 6 is a cross-sectional view of a wafer holder that includes a first reflector plate different from that shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view of the wafer holder provided with two first reflectors shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view of a wafer holder that includes two first reflectors different from those in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0010] <1> A wafer holder according to an embodiment is a wafer holder placed within a chamber, and includes a mounting plate having an upper surface on which a wafer is placed and a lower surface opposite the upper surface, a support body supporting the lower surface, and a first reflector facing a portion of the lower surface not covered by the support body, wherein the distance L1 between the lower surface and the upper surface of the first reflector is 0.1 mm or more and 60 mm or less, and the emissivity of the first reflector is equal to or less than the emissivity of the mounting plate.

[0011] Emissivity is an index that indicates the ease with which an object radiates heat and is a dimensionless quantity between 0 and 1. A material with low emissivity is more likely to reflect radiant heat. By positioning a first reflector, which has an emissivity equal to or lower than that of the mounting plate, at a predetermined distance from the lower surface of the mounting plate, heat is less likely to dissipate to the region below the first reflector in the chamber and more likely to remain in the region above the first reflector. Here, the emissivity of the mounting plate is the average emissivity of the lower surface of the mounting plate facing the first reflector. As a result, the temperature of the mounting plate is less likely to drop, and the power required to maintain the mounting plate at a predetermined temperature is reduced. This reduces the power consumption of semiconductor processing equipment equipped with the wafer holder.

[0012] Here, when the first reflector is in contact with the underside of the mounting plate, the power required to heat the mounting plate to a desired temperature is large. This is because a contact configuration is almost equivalent to a configuration in which the mounting plate is thicker, i.e., a configuration in which the heat capacity of the mounting plate is increased. Therefore, when the first reflector is in contact with the underside of the mounting plate, the power consumption of the semiconductor processing apparatus is not reduced.

[0013] <2> the above <1> In the wafer holder described in 1. above, a plurality of the first reflectors may be provided, and the plurality of first reflectors may be arranged at intervals in a direction away from the lower surface.

[0014] By arranging multiple first reflectors at intervals in a direction away from the underside of the support plate, i.e., downward, the temperature of the support plate is less likely to drop, and the power required to maintain the support plate at a predetermined temperature is reduced.

[0015] <3> the above <1> or <2> In the wafer holder described in 1. above, the first reflecting plate may be made of stainless steel, aluminum oxide, or aluminum nitride.

[0016] For example, if the semiconductor processing apparatus is a film deposition apparatus, the temperature near the support plate will be 500°C or higher. Stainless steel, aluminum oxide, and aluminum nitride all have excellent heat resistance and can be used even when placed near a high-temperature support plate. Aluminum nitride, in particular, has excellent heat resistance. A first reflector made of aluminum nitride is less likely to develop defects such as cracks at high temperatures of 500°C or higher.

[0017] <4> the above <3> In the wafer holder described in 1. above, the first reflecting plate may be made of stainless steel, and the distance L1 may be 0.1 mm or more and 50 mm or less.

[0018] As shown in Test Example 2 described later, if the distance L1 between the mounting plate and the first reflecting plate made of stainless steel is 0.1 mm or more and 50 mm or less, the power consumption of the semiconductor processing apparatus is likely to be reduced.

[0019] <5> the above <3> In the wafer holder described in 1. above, the first reflecting plate may be made of aluminum oxide, and the distance L1 may be 0.1 mm or more and 40 mm or less.

[0020] As shown in Test Example 3 described later, if the distance L1 between the mounting plate and the first reflecting plate made of aluminum oxide is 0.1 mm or more and 40 mm or less, the power consumption of the semiconductor processing apparatus is likely to be reduced.

[0021] <6> the above <3> In the wafer holder described in 1. above, the first reflecting plate may be made of aluminum nitride, and the distance L1 may be 0.1 mm or more and 40 mm or less.

[0022] As shown in Test Example 4 described later, if the distance L1 between the mounting plate and the first reflecting plate made of aluminum nitride is 0.1 mm or more and 40 mm or less, the power consumption of the semiconductor processing apparatus is likely to be reduced.

[0023] <7> the above <1> from <6> In the wafer holder described in any one of the above, a spacer may be disposed between the lower surface and the first reflecting plate, and the first reflecting plate may be fixed to the lower surface by the spacer so as to ensure the distance L1.

[0024] By fixing the first reflector to the underside of the mounting plate via a spacer, the first reflector does not come into contact with components other than the mounting plate, such as the support. Because no conduction path is formed from the mounting plate through the support to the first reflector, heat dissipation from the mounting plate to the first reflector due to conduction is suppressed. The distance L1 does not need to be strictly constant within the plane of the first reflector, and errors due to unevenness or tilt of the surface are allowed.

[0025] <8> the above <1> from <7> In any one of the wafer holders described above, the first reflector may include an outer wall portion extending upward from an outer periphery of the first reflector.

[0026] The outer wall portion can cover the space between the mounting plate and the first reflector near the outer peripheral surface of the first reflector. This outer wall portion makes it difficult for heat in the space between the mounting plate and the first reflector to escape to the outside of the space. As a result, the temperature of the mounting plate is difficult to drop, and the power required to maintain the mounting plate at a predetermined temperature can be easily reduced.

[0027] <9> the above <8> In the wafer holder described in 1, the first reflecting plate may include an inner wall portion extending upward from an inner periphery of the first reflecting plate.

[0028] The inner wall portion can cover the space between the mounting plate and the first reflector near the inner circumferential surface of the first reflector. This inner wall portion makes it difficult for heat in the space between the mounting plate and the first reflector to escape to the outside of the space. As a result, the temperature of the mounting plate is difficult to drop, and the power required to maintain the mounting plate at a predetermined temperature can be easily reduced.

[0029] <10> The semiconductor processing apparatus according to the embodiment is <1> from <9> and a chamber in which the wafer holder is disposed.

[0030] In the semiconductor processing apparatus, the first reflector tends to retain heat in the region above the first reflector within the chamber, making it difficult for the temperature of the support plate to drop, reducing the amount of power required to maintain the support plate at a predetermined temperature, thereby reducing the amount of power consumed by the semiconductor processing apparatus.

[0031] <11> the above <10> The semiconductor processing apparatus described above may further include a second reflector disposed inside the chamber, the chamber having an inner bottom surface facing the lower surface of the first reflector, the second reflector being disposed on the inner bottom surface, and the emissivity of the second reflector being less than the emissivity of the inner bottom surface.

[0032] A member with low emissivity tends to reflect radiant heat. The second reflector with low emissivity placed on the inner bottom surface of the chamber tends to reflect radiant heat from the mounting plate and the first reflector back into the chamber. This makes it difficult for the temperature inside the chamber to drop, and also makes it difficult for the temperature of the mounting plate placed inside the chamber to drop. As a result, the power consumption of the semiconductor processing equipment is reduced.

[0033] <12> the above <10> or <11> The semiconductor processing apparatus described in the above may further include a third reflector disposed inside the chamber, the chamber having an inner surface facing the outer peripheral surface of the support, the third reflector being disposed on the inner surface, and the emissivity of the third reflector being less than the emissivity of the inner surface.

[0034] The third reflector, which has low emissivity and is located on the inner surface of the chamber, easily reflects radiant heat from the mounting plate and the first reflector back into the chamber. This makes it difficult for the temperature inside the chamber to drop, and also makes it difficult for the temperature of the mounting plate placed inside the chamber to drop. As a result, the power consumption of the semiconductor processing equipment is reduced.

[0035] [Details of the embodiments of the present disclosure] Specific examples of wafer holders according to embodiments of the present disclosure will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same or corresponding parts. It should be noted that the present invention is not limited to these examples, but is defined by the claims, and all modifications within the meaning and scope of the claims are intended to be included.

[0036] <Embodiment 1> <Overall structure> A semiconductor processing apparatus 1 and a wafer holder 2 according to a first embodiment will be described with reference to FIGS. 1 and 2. The semiconductor processing apparatus 1 shown in FIGS. 1 and 2 is a film formation apparatus for forming a film on a wafer (not shown). As shown in FIG. 1, the semiconductor processing apparatus 1 includes a wafer holder 2 disposed in a chamber 9. The semiconductor processing apparatus 1 of this example includes a configuration for reducing the amount of power consumed by the semiconductor processing apparatus 1. Below, the basic configuration of the wafer holder 2 and chamber 9 included in the semiconductor processing apparatus 1 of this example will be described, followed by a configuration for reducing the amount of power consumed by the semiconductor processing apparatus 1.

[0037] <Wafer holder> The wafer holder 2 includes a mounting plate 20 and a support 25. In this example, the mounting plate 20 has a disk shape. As shown in FIG. 2, the mounting plate 20 has an upper surface 20U that faces upward in the semiconductor processing apparatus 1, and a lower surface 20L that faces downward. In other words, the lower surface 20L is the surface opposite the upper surface 20U. A wafer is placed on the upper surface 20U of the mounting plate 20 when a coating is formed on the surface of the wafer in the semiconductor processing apparatus 1 of this example. The wafer is, for example, a silicon wafer.

[0038] The material of the mounting plate 20 is, for example, ceramics. Examples of ceramics include aluminum nitride, aluminum oxide, and silicon carbide. The material of the mounting plate 20 may be a composite material of the above ceramics and a metal. Examples of metals include aluminum, aluminum alloy, copper, and copper alloy. Aluminum nitride is particularly suitable as a material for the mounting plate 20 because of its excellent heat resistance. The emissivity of aluminum nitride is, for example, approximately 0.85 at 550°C.

[0039] A heater 21 is disposed inside the mounting plate 20. The heater 21 is a heat source that heats the wafer placed on the upper surface 20U of the mounting plate 20. Heat from the heater 21 is transferred from the inside of the mounting plate 20 to the upper surface 20U, heating the wafer.

[0040] The heater 21 of this example includes a resistance heating element 21R, a power supply that supplies power to the resistance heating element 21R, and a power line connecting the resistance heating element 21R and the power supply. The power supply and power line are not shown in FIG. 1 . The resistance heating element 21R of this example is a circuit pattern formed along an imaginary plane parallel to the upper surface 20U. The material of the resistance heating element 21R is, for example, one selected from the group consisting of stainless steel, nickel, nickel alloy, silver, silver alloy, tungsten, tungsten alloy, molybdenum, molybdenum alloy, chromium, and chromium alloy. The nickel alloy is, for example, nichrome.

[0041] A temperature sensor (not shown) is disposed inside the mounting plate 20. The temperature sensor is for monitoring the temperature of the mounting plate 20. The heater 21 is controlled based on temperature information from the temperature sensor.

[0042] Additionally, a coolant flow path (not shown) may be arranged inside the mounting plate 20. A coolant is supplied to the coolant flow path as needed. The coolant flow path is configured to quickly cool the mounting plate 20 heated by the heater 21. By quickly cooling the mounting plate 20, the time required to start processing a new wafer can be shortened.

[0043] As shown in FIG. 1 , the support 25 supports the lower surface 20L of the mounting plate 20. The support 25 has a cylindrical shape. The shape of the support 25 is not particularly limited. In this example, the support 25 is cylindrical. The support 25 is arranged roughly concentrically with the mounting plate 20. In this example, the mounting plate 20 is attached on the support 25 so that the central axis of the cylindrical support 25 and the central axis of the disk-shaped mounting plate 20 are coaxial. Inside the support 25, power lines and the like connected to the resistance heating element 21R are arranged. In addition, sensor lines and the like extending from a temperature sensor are arranged inside the support 25.

[0044] The support 25 has an upper end 25U and a lower end 25L. The upper end 25U and the lower end 25L each have a flange shape. The upper end 25U is attached to the lower surface 20L of the mounting plate 20. The lower surface 20L of the mounting plate 20 is covered by the support 25 at the portion where the flange contacts and in the area surrounded by the flange. A sealing member (not shown) is disposed between the upper end 25U and the lower surface 20L. The lower end 25L is attached to the bottom surface of the chamber 9, which will be described later. A sealing member (not shown) is disposed between the lower end 25L and the bottom surface of the chamber 9. These sealing members keep the interior of the support 25 airtight. Although not shown, holes are formed in the bottom surface of the chamber 9 for leading out the power lines of the heater 21 and the sensor lines of the temperature sensor.

[0045] The material of the support 25 is, for example, ceramics. The material of the support 25 may be the same as the material of the mounting plate 20, or may be different.

[0046] Chamber The chamber 9 serves to separate the space for film formation from the outside. In this example, the chamber 9 comprises an upper chamber 9U and a lower chamber 9L. The upper chamber 9U has an inner peripheral surface shape that follows the outer shape of the mounting plate 20. The lower chamber 9L has an inner peripheral surface shape that follows the outer shape of the support 25. The internal space of the upper chamber 9U and the internal space of the lower chamber 9L are connected to form the internal space of the chamber 9. In the semiconductor processing apparatus 1 of this example, a reaction gas is filled in the internal space of the chamber 9. The reaction gas is sealed in the internal space of the chamber 9 so as not to leak into the external space.

[0047] The chamber 9 is made of, for example, an aluminum alloy. The inner surface includes an inner bottom surface 90 and an inner side surface 91, which will be described later. The inner surface of the chamber 9 may be subjected to a surface treatment. The emissivity of the inner surface of the chamber 9 changes depending on the surface treatment. The emissivity of the inner surface of the chamber 9 can be, for example, approximately 0.2 to 0.9.

[0048] The chamber 9 of this example is equipped with a shower head 95 that sprays a reactive gas toward a wafer placed on the upper surface 20U (FIG. 2) of the mounting plate 20 during film formation. The shower head 95 is disposed in the ceiling portion of the upper chamber 9U.

[0049] <Configuration for reducing power consumption of semiconductor processing equipment> As a configuration for reducing the power consumption of semiconductor processing apparatus 1, semiconductor processing apparatus 1 of this example is equipped with first reflector 3, second reflector 4, and third reflector 5. First reflector 3 is provided on wafer holder 2. Second reflector 4 and third reflector 5 are provided on chamber 9. Second reflector 4 and third reflector 5 are not essential components. The following description will mainly refer to FIG. 2.

[0050] [First reflector] First reflector 3 is disposed at a position below and spaced apart from underside 20L of mounting plate 20. The emissivity of first reflector 3 is equal to or lower than that of mounting plate 20. A first reflector 3 having an emissivity equal to or lower than that of mounting plate 20 easily reflects radiant heat from mounting plate 20 upward. By disposing first reflector 3 at a predetermined distance from underside 20L, heat is less likely to dissipate to the region below first reflector 3 within chamber 9, and heat is more likely to remain in the region above first reflector 3. As a result, the temperature of mounting plate 20 is less likely to drop, and the power required to maintain mounting plate 20 at a desired temperature is reduced. Therefore, wafer holder 2 can reduce the power consumption of semiconductor processing apparatus 1.

[0051] Unlike this example, if the first reflecting plate 3 were bonded to the mounting plate 20, the difference between the linear expansion coefficients of the first reflecting plate 3 and the mounting plate 20 would cause distortion of the mounting plate 20, which could result in a decrease in flatness of the mounting plate 20. If the first reflecting plate 3 is positioned away from the mounting plate 20 as in this example, distortion of the mounting plate 20 due to the difference in linear expansion coefficients can be prevented.

[0052] The distance L1 between the upper surface 3U of the first reflecting plate 3 and the lower surface 20L of the mounting plate 20 is 0.1 mm or more and 60 mm or less. If the distance L1 is in the range of 0.1 mm or more and 60 mm or less, the power consumption of the semiconductor processing apparatus 1 can be reduced. Here, if the first reflecting plate 3 is in contact with the lower surface 20L of the mounting plate 20, heat is likely to transfer from the mounting plate 20 to the first reflecting plate 3 by heat conduction. The preferable range of the distance L1 varies depending on the material of the first reflecting plate 3, as will be described later.

[0053] There may be more than one first reflecting plate 3. For example, as shown in Fig. 3, there may be two first reflecting plates 3. Unlike the example shown in Fig. 3, there may be three or more first reflecting plates 3. In Fig. 3, the chamber 9 is not shown.

[0054] The multiple first reflectors 3 are arranged at intervals downward. As the number of first reflectors 3 increases, it becomes more difficult to lower the temperature of the mounting plate 20, and the amount of power consumption by the semiconductor processing apparatus 1 is reduced to a greater extent. However, the additional reduction in power consumption, which increases with each addition of a first reflector 3, tends to decrease as the number of first reflectors 3 increases. Furthermore, each additional first reflector 3 increases the number of parts and the effort required to install the first reflectors 3. There are also cases where it is not possible to add more first reflectors 3 due to space constraints within the chamber 9. For these reasons, the preferred number of first reflectors 3 is between two and four, and even between two and three.

[0055] The distance L1 between the upper surface 3U of the second or subsequent first reflector 3 and the lower surface 20L of the mounting plate 20 is also 0.1 mm or more and 60 mm or less. However, because the first first reflector 3 is already present, the lower limit of 0.1 mm cannot be achieved. The lower limit is the distance from the lower surface 3L of the first reflector 3 above it to the lower surface 20L of the mounting plate 20 plus 0.1 mm. The distance L2 between two adjacent first reflectors 3 may be 0.1 mm or more. The distance L2 is, for example, 0.1 mm or more and 10 mm or less. The distance L2 may be 1.0 mm or more and 5.0 mm or less, or 2.0 mm or more and 5.0 mm or less.

[0056] In the semiconductor processing apparatus 1 of this embodiment, the mounting plate 20 is heated to, for example, 500°C or higher during film formation. In other words, the mounting plate 20 is repeatedly exposed to temperature changes between room temperature and temperatures above 500°C. The first reflector 3 disposed near the mounting plate 20 is also exposed to drastic temperature changes. Therefore, the first reflector 3 may be made of a material with excellent heat resistance. Heat resistance here means that the first reflector 3 does not soften at the ambient temperature near the first reflector 3 during film formation, for example, 500°C. Examples of materials for such a first reflector 3 include stainless steel, aluminum oxide, or aluminum nitride. Aluminum oxide or aluminum nitride, which are ceramics, are less susceptible to thermal deformation than stainless steel, potentially reducing the frequency of replacement during use of the semiconductor processing apparatus 1.

[0057] Stainless steel tends to have low emissivity. For example, the emissivity of SUS316, a type of stainless steel, is approximately 0.15 under the temperature conditions during film formation. A first reflecting plate 3 with low emissivity tends to reflect radiant heat from the mounting plate 20 upward. Therefore, a first reflecting plate 3 made of stainless steel tends to reduce the power consumption of the semiconductor processing apparatus 1.

[0058] When the first reflector 3 is made of stainless steel, the power consumption of the semiconductor processing apparatus 1 is likely to be reduced if the distance L1 is 0.1 mm or more and 50 mm or less. The distance L1 may be 0.1 mm or more and 20 mm or less, or may be 2 mm or more and 10 mm or less. When an improvement in the wafer range shown in Test Example 2 is desired, the distance L1 may be, for example, 1 mm or more and 15 mm or less.

[0059] The emissivity of aluminum oxide changes with temperature. At 450°C, the emissivity is approximately 0.66, and decreases as the temperature increases. At the temperature conditions during film formation, the emissivity of aluminum oxide is approximately 0.5.

[0060] When the first reflector 3 is made of aluminum oxide, the power consumption of the semiconductor processing apparatus 1 is likely to be reduced if the distance L1 is 0.1 mm or more and 40 mm or less. The distance L1 may be 1 mm or more and 25 mm or less, 1 mm or more and 15 mm or less, or 3 mm or more and 6 mm or less. When an improvement in the wafer range shown in Test Example 3 is desired, the distance L1 may be, for example, 5 mm or more and 7 mm or less.

[0061] Here, aluminum oxide expands more easily than aluminum nitride in environments above 500°C. If the first reflector 3 made of aluminum oxide is large, a large temperature difference between the center and outer periphery of the first reflector 3 may cause cracks in the first reflector 3 due to the thermal stress. Therefore, it is preferable that the first reflector 3 made of aluminum oxide is constructed by connecting multiple divided pieces. In a first reflector 3 made of multiple divided pieces, cracks are less likely to occur in each of the divided pieces. Therefore, the function of the first reflector 3 is more likely to be maintained. The number of divided pieces is, for example, three or four.

[0062] The emissivity of aluminum nitride changes with temperature. At 460°C, the emissivity is approximately 0.79, and increases as the temperature rises. At 550°C, the emissivity of aluminum nitride is approximately 0.85.

[0063] Aluminum nitride has excellent heat resistance. The first reflector 3 made of aluminum nitride is unlikely to expand in an environment of 500°C or higher, and cracks caused by expansion are unlikely to occur. Therefore, the first reflector 3 made of aluminum nitride may be formed from a single member. Such a first reflector 3 is easy to produce and handle.

[0064] When the first reflector 3 is made of aluminum nitride, the power consumption of the semiconductor processing apparatus 1 is likely to be reduced if the distance L1 is 0.1 mm or more and 40 mm or less. The distance L1 may be 1 mm or more and 20 mm or less, or may be 2 mm or more and 10 mm or less. When an improvement in the wafer range shown in Test Example 4 is desired, the distance L1 may be, for example, 2 mm or more and 15 mm or less.

[0065] In this example, the first reflector 3 has an annular shape. The outer peripheral surface of the support 25 and the inner peripheral surface of the first reflector 3 are spaced apart by 1 mm or more in a direction from the central axis of the support 25 toward the outer periphery of the support 25. Because the first reflector 3 is spaced apart from the support 25, i.e., the inner peripheral surface of the annular first reflector 3 is not in contact with the support 25, no heat transfer path is formed from the mounting plate 20 through the support 25 to the first reflector 3. Therefore, heat from the mounting plate 20 is less likely to dissipate to a region below the first reflector 3. The first reflector 3 may be positioned so as to overlap the upper end 25U of the support 25 in the height direction, or may be positioned below the upper end 25U but not overlapping the upper end 25U. When the first reflector 3 is positioned so as not to overlap the upper end 25U, the inner diameter of the first reflector 3 may be smaller than the outer diameter of the upper end 25U. An upper end 25U of the support 25 is spaced apart from an upper surface 3U of the first reflecting plate 3 by 1 mm or more in a direction along the axis of the support 25. In this case, the gap formed between the inner peripheral surface of the first reflecting plate 3 and the outer peripheral surface of the support 25 has a curved shape, so that heat from the mounting plate 20 is less likely to dissipate to the region below the first reflecting plate 3.

[0066] The outer diameter of the annular first reflecting plate 3 may be smaller, the same as, or larger than the outer diameter of the mounting plate 20. The first reflecting plate 3 covers most of the lower surface 20L of the mounting plate 20, which makes it easier to retain heat in the region above the first reflecting plate 3. For example, when the area of ​​the lower surface 20L excluding the portion connected to the upper end 25U of the support 25 is taken as area S0 and the area of ​​the upper surface 3U of the first reflecting plate 3 is taken as S1, the area ratio S1 / S0 is 0.9 or more. The upper surface 3U of the first reflecting plate 3 is the surface facing the lower surface 20L of the mounting plate 20.

[0067] The thickness of the first reflector 3 is, for example, 1 mm or more and 10 mm or less. If the thickness of the first reflector 3 is 1 mm or more, heat is more likely to be retained in the region above the first reflector 3. If the thickness of the first reflector 3 is 10 mm or less, an increase in the size of the first reflector 3, and therefore an increase in the size of the semiconductor processing apparatus 1, is suppressed. The thickness of the first reflector 3 may be 2 mm or more and 5 mm or less.

[0068] In this example, the first reflecting plate 3 is fixed to the lower surface 20L of the mounting plate 20 together with a spacer 30. The spacer 30 is disposed between the mounting plate 20 and the first reflecting plate 3. The upper end surface of the spacer 30 is in contact with the lower surface 20L of the mounting plate 20, and the lower end surface of the spacer 30 is in contact with the upper surface 3U of the first reflecting plate 3. The spacer 30 allows the distance L1 and the distance L2 to be accurately determined.

[0069] The spacer 30 in this example has a cylindrical shape. A fixing member 31 passes through the interior of the spacer 30. The fixing member 31 in this example is a screw. The head of the screw abuts against the lower surface 3L of the first reflecting plate 3. The tip of the screw is screwed into the mounting plate 20.

[0070] The low thermal conductivity of the spacer 30 reduces the heat conduction from the mounting plate 20 to the first reflector 3. Similarly, the low thermal conductivity of the fixing member 31 reduces the heat conduction from the mounting plate 20 to the first reflector 3. Therefore, the spacer 30 and the fixing member 31 are made of a material with a thermal conductivity of 50 W / mK or less, for example, to reduce the heat conduction from the mounting plate 20 to the first reflector 3. The material of the spacer 30 and the fixing member 31 is aluminum oxide, for example. In consideration of heat resistance and the like, the material of the spacer 30 and the fixing member 31 may be silicon nitride or aluminum nitride, for example.

[0071] As shown in FIGS. 4 to 8, the first reflecting plate 3 may include at least one of an outer wall portion 35 and an inner wall portion 36.

[0072] As shown in FIG. 4 , the outer wall portion 35 extends upward from the outer periphery of the first reflector 3. The outer periphery of the first reflector 3 includes the outer periphery of the first reflector 3 and a portion of the upper surface 3U near the outer periphery. The outer wall portion 35 shown in FIG. 4 is a member that covers the gap between the mounting plate 20 and the first reflector 3 near the outer periphery of the first reflector 3. The outer wall portion 35 is an annular member that conforms to the outer periphery of the first reflector 3. The outer wall portion 35 makes it difficult for heat in the gap between the mounting plate 20 and the first reflector 3 to escape from the gap. This makes it difficult for the temperature of the mounting plate 20 to drop, and the power consumption of the semiconductor processing apparatus 1 is likely to be reduced. Furthermore, the outer wall portion 35 makes it difficult for reactive gas to flow into the gap between the mounting plate 20 and the first reflector 3. This prevents the lower surface 20L of the mounting plate 20 and the upper surface 3U of the first reflector 3 from being coated.

[0073] The outer wall portion 35 may be formed integrally with the first reflecting plate 3. In this case, the upper end of the outer wall portion 35 may be in contact with the lower surface 20L of the mounting plate 20, or may be spaced apart from the lower surface 20L. If the upper end of the outer wall portion 35 is spaced apart from the lower surface 20L of the mounting plate 20, heat conduction from the mounting plate 20 to the first reflecting plate 3 is suppressed.

[0074] The outer wall portion 35 may be a member independent of the first reflecting plate 3. In this case, the outer wall portion 35 may be fixed to the first reflecting plate 3 or to the mounting plate 20. The outer wall portion 35 may be made of the same material as the first reflecting plate 3, or may be made of a different material. If the outer wall portion 35 is made of a material different from that of the first reflecting plate 3, the low thermal conductivity of the outer wall portion 35 suppresses heat conduction from the mounting plate 20 to the first reflecting plate 3. For example, the thermal conductivity of the outer wall portion 35 is 50 W / mK or less. The material of the outer wall portion 35 is, for example, aluminum oxide. In consideration of heat resistance and the like, the material of the outer wall portion 35 may be, for example, silicon nitride or aluminum nitride.

[0075] The outer wall portion 35 may also serve as the spacer 30. That is, the outer wall portion 35 may be sandwiched between the lower surface 20L of the mounting plate 20 and the upper surface 3U of the first reflecting plate 3. In this case, the outer wall portion 35 functions as the spacer 30.

[0076] The first reflector 3 shown in FIG. 5 includes an inner wall 36 in addition to an outer wall 35. The inner wall 36 extends upward from the inner periphery of the first reflector 3. The inner periphery of the first reflector 3 includes the inner periphery of the first reflector 3, which is adjacent to the outer periphery of the support 25. The inner wall 36 shown in FIG. 5 is a member that covers the gap between the mounting plate 20 and the first reflector 3 near the inner periphery of the first reflector 3. The inner wall 36 is an annular member that conforms to the inner periphery of the first reflector 3. The inner wall 36 prevents heat from escaping from the gap between the mounting plate 20 and the first reflector 3. This prevents the temperature of the mounting plate 20 from dropping, which contributes to reducing the power consumption of the semiconductor processing apparatus 1. The inner wall 36 also prevents reactive gas from flowing into the gap between the mounting plate 20 and the first reflector 3. Therefore, the lower surface 20L of the mounting plate 20 and the upper surface 3U of the first reflecting plate 3 can be prevented from being coated.

[0077] The configurations of the outer wall portion 35 and the inner wall portion 36 are not limited to those shown in Fig. 4 and Fig. 5. For example, the outer wall portion 35 shown in Fig. 6 covers the outer peripheral surface of the mounting plate 20 from the sides. This configuration also makes it difficult for heat in the gap between the mounting plate 20 and the first reflecting plate 3 to escape to the outside of the gap.

[0078] The wafer holder 2 shown in Fig. 7 includes two first reflectors 3, 3. Each of the first reflectors 3, 3 has the same configuration as the first reflector 3 shown in Fig. 5. With this configuration, heat in the gap between the upper and lower first reflectors 3 is less likely to escape from the gap.

[0079] The wafer holder 2 shown in FIG. 8 includes two first reflectors 3, 3. The upper first reflector 3 includes only an inner wall portion 36, and does not include an outer wall portion 35. The lower first reflector 3 includes both an inner wall portion 36 and an outer wall portion 35. The outer wall portion 35 of the lower first reflector 3 is higher than the inner wall portion 36 and covers the outer peripheral surface of the mounting plate 20 from the side. This outer wall portion 35 makes it difficult for heat in the gap between the mounting plate 20 and the upper first reflector 3, and in the gap between the upper first reflector 3 and the lower first reflector 3, to escape to the outside of the gap.

[0080] [Second and third reflectors] As shown in Figures 1 and 2, a semiconductor processing apparatus 1 equipped with a first reflector 3 may further be configured to include a second reflector 4 but not a third reflector 5, or to include a third reflector 5 but not the second reflector 4, or to include both the second reflector 4 and the third reflector 5.

[0081] The second reflector 4 is disposed on the inner bottom surface 90 of the chamber 9. The inner bottom surface 90 is the surface facing the lower surface 3L of the first reflector 3. In this example, it is the surface facing the lower surface 3L of the first reflector 3 among the inner peripheral surfaces of the upper chamber 9U.

[0082] The emissivity of the second reflector 4 is lower than the emissivity of the inner bottom surface 90 of the chamber 9. The second reflector 4, which has low emissivity, easily reflects radiant heat from the mounting plate 20 and the first reflector 3 into the chamber 9. Therefore, the temperature inside the chamber 9 is less likely to decrease, and the temperature of the mounting plate 20 placed inside the chamber 9 is also less likely to decrease. As a result, the power consumption of the semiconductor processing apparatus 1 is reduced.

[0083] The second reflector 4 may be in contact with the inner bottom surface 90, or may be disposed at a position away from the inner bottom surface 90. In particular, if the second reflector 4 is in contact with the inner bottom surface 90, the temperature inside the chamber 9 is less likely to drop, and the power consumption of the semiconductor processing apparatus 1 is more likely to be reduced. The second reflector 4 may be adhered to the inner bottom surface 90, or may be deposited on the inner bottom surface 90 by vapor deposition.

[0084] The thickness of the second reflector 4 is, for example, 1 mm or more and 6 mm or less. If the thickness of the second reflector 4 is 1 mm or more, the second reflector 4 easily reflects radiant heat. If the thickness of the second reflector 4 is 6 mm or less, when the second reflector 4 is adhered to the inner bottom surface 90, the second reflector 4 can be easily processed into a shape that conforms to the inner bottom surface 90. Furthermore, when the second reflector 4 is formed by vapor deposition, the time required to form the second reflector 4 is not too long. The thickness of the second reflector 4 may be 2 mm or more and 4 mm or less.

[0085] The third reflector 5 is disposed on an inner surface 91 of the chamber 9. The inner surface 91 is a surface facing the outer peripheral surface of the support 25. In this example, it is the surface of the inner peripheral surface of the upper chamber 9U that faces the outer peripheral surface of the support 25.

[0086] The emissivity of the third reflector 5 is lower than the emissivity of the inner surface 91 of the chamber 9. The third reflector 5, which has low emissivity, easily reflects radiant heat from the mounting plate 20 and the first reflector 3 into the chamber 9. Therefore, the temperature inside the chamber 9 is less likely to decrease, and the temperature of the mounting plate 20 placed inside the chamber 9 is also less likely to decrease. As a result, the power consumption of the semiconductor processing apparatus 1 is reduced.

[0087] The third reflector 5 may be in contact with the inner surface 91, or may be disposed at a position separated from the inner surface 91. In particular, if the third reflector 5 is in contact with the inner surface 91, the temperature inside the chamber 9 is less likely to drop, and the power consumption of the semiconductor processing apparatus 1 is more likely to be reduced. The third reflector 5 may be bonded to the inner surface 91, or may be deposited on the inner surface 91.

[0088] The thickness of the third reflector 5 is, for example, 0.5 mm or more and 3 mm or less. If the thickness of the third reflector 5 is 0.5 mm or more, the third reflector 5 easily reflects radiant heat. If the thickness of the third reflector 5 is 3 mm or less, when the third reflector 5 is bonded to the inner surface 91, the third reflector 5 can be easily processed into a shape that conforms to the inner surface 91. In particular, if the thickness of the third reflector 5 is 1 mm or less, processing is easy. Furthermore, when the third reflector 5 is formed by vapor deposition, the time required to form the third reflector 5 is not too long. The thickness of the third reflector 5 may be 0.5 mm or more and 1 mm or less.

[0089] The second reflector 4 and the third reflector 5 are made of a material with an emissivity of, for example, 0.15 or less. Such a material is, for example, a metal such as an aluminum alloy. An example of an aluminum alloy is A5052, an internationally registered alloy number. A5052 is an aluminum alloy containing iron, copper, manganese, magnesium, chromium, zinc, and titanium, with the remainder being aluminum and unavoidable impurities. The materials of the second reflector 4 and the third reflector 5 may be the same or different. However, if the inner surface of the chamber 9 is subjected to a surface treatment such as anodizing or sandblasting, the emissivity of the inner surface of the chamber 9 will change depending on the surface treatment. For example, if the emissivity of the inner surface of the chamber 9 is high, such as approximately 0.9, the materials of the second reflector 4 and the third reflector 5 may be made of a material with an emissivity of 0.75 or less.

[0090] The second reflecting plate 4 and the third reflecting plate 5 are disposed at positions farther from the mounting plate 20 than the first reflecting plate 3. Therefore, the second reflecting plate 4 and the third reflecting plate 5 are not required to have the same heat resistance as the first reflecting plate 3.

[0091] <Test example> In the test example, a simulation was conducted to examine the effect of the first reflector 3 in reducing the amount of power consumed by the semiconductor processing apparatus 1. The simulation was performed using multiphysics analysis software from Ansys.

[0092] <Test Example 1> Test Example 1 investigated the effect of the presence or absence of the first reflector 3 on reducing the amount of power consumption of the semiconductor processing apparatus 1. The samples on which the effect was investigated are outlined below.

[0093] The diameter of the mounting plate 20 of the semiconductor processing apparatus 1 of sample No. 1-1 was 350 mm, and the thickness of the mounting plate 20 was 22 mm. The material of the mounting plate 20 was aluminum nitride. The emissivity of the mounting plate 20 at 550°C was 0.85. The semiconductor processing apparatus 1 of sample No. 1-1 was a reference configuration that did not include the first reflector 3, the second reflector 4, and the third reflector 5. Hereinafter, sample No. 1-1 will be referred to as the reference sample.

[0094] Sample No. 1-2 differs from Sample No. 1-1 in that it includes a first reflector 3. The material of the first reflector 3 was stainless steel, specifically SUS316. The emissivity of stainless steel at 550°C was 0.15. The thickness of the first reflector 3 was 3 mm. In addition, the distance L1 from the lower surface 20L of the mounting plate 20 to the upper surface 3U of the first reflector 3 was 4 mm.

[0095] Sample No. 1-3 differs from Sample No. 1-2 in the material of the first reflector 3. The material of the first reflector 3 was aluminum oxide. The emissivity of aluminum oxide at 550°C was 0.5. The thickness of the first reflector 3 was 3 mm. In addition, the distance L1 from the lower surface 20L of the mounting plate 20 to the upper surface 3U of the first reflector 3 was 4 mm.

[0096] Sample No. 1-4 differs from Sample No. 1-2 and Sample No. 1-3 in the material of the first reflector 3. The material of the first reflector 3 was aluminum nitride. The emissivity of aluminum nitride at 550°C was 0.85. The thickness of the first reflector 3 was 3 mm. The distance L1 was 5 mm.

[0097] For each sample, the mounting plate 20 was heated from room temperature to 550°C or higher across the entire mounting plate 20, and the power consumption and wafer range were determined by simulation when the temperature of 550°C was maintained for 30 minutes. The power consumption values ​​are based on Sample No. 1-1 being 100% (percent). The wafer range is the temperature variation on the upper surface 20U of the mounting plate 20. Specifically, the temperature was measured at the center of the upper surface 20U and at positions 35 mm apart from the center toward the periphery. The difference between the maximum and minimum temperatures is the wafer range. The unit of wafer range is °C. The measurement results are shown in Table 1. In Table 1, stainless steel is referred to as "stainless steel," aluminum nitride as "AlN," and aluminum oxide as "alumina." This also applies to Test Examples 2 to 6 below.

[0098] [Table 1]

[0099] As shown in Table 1, it was found that by placing the first reflector 3 at a distance below the mounting plate 20, power consumption could be reduced by approximately 10% compared to the reference sample. It was also found that the first reflector 3 could improve the wafer range. A small wafer range means that there is little variation in the temperature of the upper surface 20U of the mounting plate 20, so the wafer can be heated uniformly. The temperature of the upper surface 20U was highest at the center, decreased as it moved away from the center, and then rose again.

[0100] <Test Example 2> In Test Example 2, the influence of the distance L1 from the lower surface 20L of the mounting plate 20 to the upper surface 3U of the first reflector 3 on the power consumption and wafer range was investigated by simulation. The material of the first reflector 3 was SUS316. The thickness of the first reflector 3 was 3 mm.

[0101] Sample No. 2-1 is a reference sample having the same configuration as Sample No. 1-1 in Test Example 1, i.e., not including the first reflector 3. The only difference between Samples No. 2-2 to No. 2-22 is the distance L1 between the upper surface 3U of the first reflector 3 made of SUS316 and the lower surface 20L of the mounting plate 20. The measurement results are shown in Table 2.

[0102] [Table 2]

[0103] As shown in Table 2, a reduction in power consumption was observed when the distance L1 was between 0.1 mm and 70 mm. When the distance L1 was between 0.1 mm and 50 mm, the power consumption was reduced to 90% or less of the reference sample. When the distance L1 was between 0.1 mm and 40 mm, the power consumption was reduced to 86% or less of the reference sample. Furthermore, when the distance L1 was between 0.1 mm and 20 mm, the power consumption was reduced to 82% or less of the reference sample. When the distance L1 was between 2 mm and 10 mm, the power consumption was reduced to 81% or less of the reference sample. Furthermore, when the distance L1 was between 0.1 mm and 70 mm, the wafer temperature was kept below 5.0°C. In particular, when the distance L1 was between 1 mm and 15 mm, the wafer temperature was kept below 2.5°C.

[0104] <Test Example 3> In Test Example 3, the influence of the distance L1 from the lower surface 20L of the mounting plate 20 to the upper surface 3U of the first reflector 3 on the power consumption and wafer range was investigated by simulation when the material of the first reflector 3 was aluminum oxide. The thickness of the first reflector 3 was 3 mm.

[0105] Sample No. 3-1 is a reference sample having the same configuration as sample No. 1-1 in Test Example 1, i.e., not including the first reflector 3. The only difference between samples No. 3-2 to No. 3-22 is the distance L1 between the upper surface 3U of the first reflector 3 made of aluminum oxide and the lower surface 20L of the mounting plate 20. The measurement results are shown in Table 3.

[0106] [Table 3]

[0107] As shown in Table 3, a reduction in power consumption was observed when the distance L1 was between 0.1 mm and 60 mm. When the distance L1 was between 0.1 mm and 40 mm, power consumption was reduced to 95% or less of the reference sample. When the distance L1 was between 0.1 mm and 30 mm, power consumption was reduced to 93% or less of the reference sample. When the distance L1 was between 1 mm and 25 mm, power consumption was reduced to 92% or less of the reference sample. When the distance L1 was between 1 mm and 15 mm, power consumption was reduced to 91% or less of the reference sample. In particular, when the distance L1 was between 3 mm and 6 mm, power consumption was reduced to 90% or less of the reference sample. Furthermore, when the distance L1 was between 0.1 mm and 60 mm, a reduction in wafer temperature was observed. When the distance L1 was between 1 mm and 30 mm, the wafer temperature was kept below 5.0°C. In particular, when the distance L1 was between 5 mm and 7 mm, the wafer temperature was kept below 4.0°C.

[0108] Test Example 4 In Test Example 4, the influence of the distance L1 from the lower surface 20L of the mounting plate 20 to the upper surface 3U of the first reflector 3 on the power consumption and wafer range was investigated by simulation when the material of the first reflector 3 was aluminum nitride. The thickness of the first reflector 3 was 3 mm.

[0109] Sample No. 4-1 is a reference sample having the same configuration as sample No. 1-1 in Test Example 1, i.e., not including the first reflector 3. The only difference between samples No. 4-2 to No. 4-22 is the distance L1 between the upper surface 3U of the first reflector 3 made of aluminum nitride and the lower surface 20L of the mounting plate 20. The measurement results are shown in Table 4.

[0110] [Table 4]

[0111] As shown in Table 4, a reduction in power consumption was observed when the distance L1 was between 0.1 mm and 60 mm. When the distance L1 was between 0.1 mm and 40 mm, power consumption was reduced to 96% or less of that of the reference sample. When the distance L1 was between 0.1 mm and 30 mm, power consumption was reduced to 95% or less of that of the reference sample. When the distance L1 was between 1 mm and 20 mm, power consumption was reduced to 94% or less of that of the reference sample. In particular, when the distance L1 was between 2 mm and 10 mm, power consumption was reduced to 93% or less of that of the reference sample. Furthermore, when the distance L1 was between 0.1 mm and 60 mm, a reduction in wafer temperature was observed. When the distance L1 was between 1 mm and 20 mm, the wafer temperature was kept below 5.0°C. In particular, when the distance L1 was between 2 mm and 15 mm, the wafer temperature was kept below 4.7°C.

[0112] Test Example 5 In Test Example 5, the power consumption and wafer range of a semiconductor processing apparatus 1 equipped with a second reflector 4 or a third reflector 5 in addition to a first reflector 3 were determined by simulation. The chamber 9 in this example was made of an aluminum alloy with a surface-treated inner circumferential surface, and the emissivity of the inner circumferential surface was 0.2.

[0113] The outer diameter of the support plate 20 in each sample in Test Example 5 was 340 mm, and the thickness of the support plate 20 was 19 mm. In other words, the size of the support plate 20 in Test Example 5 differed slightly from those in Test Examples 1 to 4. Sample No. 5-1 included a first reflector 3 but did not include a second reflector 4 or a third reflector 5. Samples No. 5-2 to 5-5 included a first reflector 3 and either a second reflector 4 or a third reflector 5. The first reflector 3 in each sample was made of aluminum nitride, and the distance L1 was 5 mm. The second reflector 4 and the third reflector 5 were made of aluminum alloy with the internationally registered alloy number A5052 or aluminum oxide. The emissivity of A5052 at 550°C was 0.1. The thickness of the second reflector 4 and the third reflector 5 was 2 mm.

[0114] In Test Example 5, the power consumption of each sample was calculated assuming that the power consumption in the configuration of Sample No. 5-1 was 100%. The results are shown in Table 5.

[0115] [Table 5]

[0116] A comparison of Samples No. 5-1 to No. 5-3 in Table 5 reveals that adding a second reflector 4 or a third reflector 5 with an emissivity of less than 0.15 to the semiconductor processing equipment 1 can reduce the amount of power consumed by the semiconductor processing equipment 1. On the other hand, as shown in Samples No. 5-4 and No. 5-5, it was found that when the emissivity of the second reflector 4 or the third reflector 5 is 0.15 or higher, the amount of power consumed actually increases.

[0117] Although not shown in Table 5, it is expected that the power consumption of the semiconductor processing apparatus 1 can be further reduced by adding both the second reflector 4 and the third reflector 5 in addition to the first reflector 3.

[0118] <Demonstration Test> In the demonstration test, the following semiconductor processing apparatuses 1 of Sample No. 6-1 to Sample No. 6-8 were fabricated, and the power consumption of the semiconductor processing apparatus 1 when the temperature of the mounting plate 20 was raised to 500°C was measured.

[0119] The configuration and dimensions of the semiconductor processing apparatus 1 of Sample No. 6-1 are the same as those of Sample No. 1-1 of Test Example 1. That is, the semiconductor processing apparatus 1 of Sample No. 6-1 has a reference configuration that does not include a first reflector 3. In the following description of Samples No. 6-2 to No. 6-8, only the differences from the reference configuration will be described.

[0120] Sample No. 6-2 differs from Sample No. 6-1 in that it includes one first reflector 3. That is, the semiconductor processing apparatus 1 of Sample No. 6-2 has the configuration shown in Figures 1 and 2. The thickness of the first reflector 3 was 3 mm, and the distance L1 from the lower surface 20L of the mounting plate 20 to the upper surface 20U of the first reflector 3 was 5 mm.

[0121] Sample No. 6-3 differs from Sample No. 6-2 in that the first reflecting plate 3 has an inner wall portion 36 and an outer wall portion 35. That is, the semiconductor processing apparatus 1 of Sample No. 6-3 has the configuration shown in FIG.

[0122] Sample No. 6-4 differs from Sample No. 6-2 in that the distance L1 is 2 mm.

[0123] Sample No. 6-5 differs from Sample No. 6-1 in that it includes two first reflectors 3. That is, the semiconductor processing apparatus 1 of Sample No. 6-5 has the configuration shown in FIG. 3. The two first reflectors 3 were both made of aluminum nitride and had a thickness of 3 mm. The distance L2 between the upper and lower first reflectors 3 was 5 mm.

[0124] Sample No. 6-6 differs from Sample No. 6-5 in that the distance L1 and the distance L2 are both 2 mm.

[0125] Sample No. 6-7 differs from Sample No. 6-6 in that the two first reflectors 3 each include an inner wall portion 36 and an outer wall portion 35. That is, the semiconductor processing apparatus 1 of Sample No. 6-7 has the configuration shown in FIG.

[0126] Sample No. 6-8 differs from Sample No. 6-5 in that the distance L1 is 5 mm and the distance L2 is 2 mm.

[0127] The main configurations and power consumption of the above-described Samples No. 6-1 to No. 6-8 are shown in Table 6. The power consumption is a value when Sample No. 6-1 is set as 100% (percent).

[0128] [Table 6]

[0129] As shown in Table 6, it was confirmed that the power consumption of Samples No. 6-2 to No. 6-8, which are provided with the first reflector 3, is 9.8% or more lower than that of Sample No. 6-1, which is not provided with the first reflector 3.

[0130] The reduction in power consumption obtained by subtracting the power consumption of sample No. 6-2 from the power consumption of sample No. 6-1 was approximately 10%, and the reduction in power consumption obtained by subtracting the power consumption of sample No. 6-5 from the power consumption of sample No. 6-1 was approximately 15%. In other words, the reduction achieved by adding the first first reflector 3 was approximately 10%, while the reduction achieved by adding a second first reflector 3 was approximately 5%. Therefore, although increasing the number of first reflectors 3 reduces power consumption, the reduction in power consumption is thought to decrease with each additional first reflector 3. The reduction in power consumption achieved by adding first reflectors 3 of the same material at the same intervals is half the reduction achieved by adding the first reflector 3 above them. When using three or more first reflectors 3, careful consideration must be given to whether the effort required to install the first reflectors 3 is worth the power consumption reduction.

[0131] A comparison between Sample No. 6-5 and Sample No. 6-8 revealed that the closer the lower first reflector 3 is to the upper first reflector 3, the more the amount of power consumption is reduced.

[0132] Comparison of Sample No. 6-2 with Sample No. 6-3, and comparison of Sample No. 6-6 with Sample No. 6-7 revealed that the inner wall portion 36 and the outer wall portion 35 can reduce the amount of power consumption. [Explanation of symbols]

[0133] 1. Semiconductor processing equipment 2 Wafer holder 20. Mounting plate 20L bottom 20U top 21 Heater 21R Resistive Heating Element 25 Support 25L bottom end 25U top end 3 First reflector 3L bottom 3U top 30 spacer 31 Fixing member 35 Exterior wall 36 Inner wall 4 Second reflector 5 Third reflector 9 Chambers 9L lower chamber 9U upper chamber 90 Inner bottom surface 91 Inner surface 95 shower head L1,L2 distance

Claims

1. a wafer holder disposed within the chamber, a mounting plate having an upper surface on which a wafer is placed and a lower surface opposite to the upper surface; a support body that supports the lower surface; a first reflector facing a portion of the lower surface that is not covered by the support, a distance L1 between the lower surface and the upper surface of the first reflector is 0.1 mm or more and 60 mm or less; The emissivity of the first reflector is equal to or lower than the emissivity of the mounting plate. Wafer holder.

2. A plurality of the first reflectors are provided, The wafer holder according to claim 1 , wherein the plurality of first reflectors are arranged at intervals in a direction away from the lower surface.

3. 3. The wafer holder according to claim 1, wherein the first reflecting plate is made of stainless steel, aluminum oxide, or aluminum nitride.

4. the first reflector is made of stainless steel, 4. The wafer holder according to claim 3, wherein the distance L1 is equal to or greater than 0.1 mm and equal to or less than 50 mm.

5. the first reflector is made of aluminum oxide, 4. The wafer holder according to claim 3, wherein the distance L1 is equal to or greater than 0.1 mm and equal to or less than 40 mm.

6. the first reflector is made of aluminum nitride, 4. The wafer holder according to claim 3, wherein the distance L1 is equal to or greater than 0.1 mm and equal to or less than 40 mm.

7. a spacer disposed between the lower surface and the first reflector; 3. The wafer holder according to claim 1, wherein the first reflector is fixed to the lower surface by the spacer so as to ensure the distance L1.

8. 3. The wafer holder according to claim 1, wherein the first reflector includes an outer wall portion extending upward from an outer periphery of the first reflector.

9. The wafer holder according to claim 8 , wherein the first reflector includes an inner wall portion extending upward from an inner periphery of the first reflector.

10. the wafer holder according to claim 1; a chamber in which the wafer holder is disposed, Semiconductor processing equipment.

11. further comprising a second reflector disposed inside the chamber; the chamber has an inner bottom surface facing the lower surface of the first reflector; the second reflector is disposed on the inner bottom surface, The semiconductor processing apparatus according to claim 10 , wherein the emissivity of the second reflector is less than the emissivity of the inner bottom surface.

12. further comprising a third reflector disposed inside the chamber; the chamber has an inner surface facing the outer circumferential surface of the support; the third reflector is disposed on the inner surface, The semiconductor processing apparatus according to claim 10 or 11, wherein the emissivity of the third reflector is less than the emissivity of the inner surface.

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