Polycrystalline sic molded body and method for producing the same

Abstract

The objective of this invention is to provide a polycrystalline SiC molded body with small crystal grain size and low volume resistivity, and a method for manufacturing the same. This invention provides an average crystal grain size of less than 5 μm and a nitrogen concentration of 2.7 × 10⁻⁶. 19 ~5.4×10 20 (pieces / cm) 3 The product of carrier density and Hall mobility is 4.0 × 10⁻⁶. 20 ~6.0×10 21 (pieces / cmVsec) of polycrystalline SiC molded bodies.

Description

Technical Field

[0001] This invention relates to polycrystalline SiC molded bodies and their manufacturing methods. Background Technology

[0002] Polycrystalline SiC (silicon carbide) molded bodies possess excellent mechanical strength, electrical properties, heat resistance, and chemical stability, making them suitable for various industrial applications. For example, SiC molded bodies are used in high-temperature and high-purity atmospheres. Common applications include: virtual wafers, components constituting semiconductor manufacturing apparatuses, and other parts used in semiconductor manufacturing processes.

[0003] For example, polycrystalline SiC molded bodies used as components in semiconductor manufacturing equipment are generally in the shape of a disc. The growth direction of the CVD film is the dominant surface of the polycrystalline SiC molded body; if it is a disc-shaped molded body, the surface excluding the sides to the back surface is the dominant surface. The thickness of the polycrystalline SiC molded body varies with the film deposition time and can be formed to any thickness. The diameter of the disc is known to be approximately 100–300 mm.

[0004] Furthermore, regarding polycrystalline SiC molded bodies used as components in semiconductor manufacturing equipment, cylindrical molded bodies are also suitable if the film is deposited on a rod-shaped substrate. In this case, the growth direction of the CVD film is the dominant plane of the polycrystalline SiC molded body, while in the case of a cylindrical molded body, the surface to the inner surface of the cylinder is the dominant plane. The thickness of the polycrystalline SiC molded body varies with the film deposition time and can be formed to any thickness. The diameter of the cylinder is known to be approximately 5–700 mm.

[0005] Regarding SiC molded bodies with specific resistivity, Patent Document 1 (Japanese Patent No. 4595153) discloses a silicon carbide body for semiconductor manufacturing components, characterized in that it is a silicon carbide body obtained by CVD, with a nitrogen content of 0.1 to 100 ppm, a metal element content other than silicon of 10 ppm or less, a resistivity of 0.01 to 10 Ω·cm, and a resistivity deviation of 10% or less. As a specific example, a silicon carbide body with a resistivity of 0.1 to 5 Ω·cm is disclosed.

[0006] Patent document 2 (Japanese Patent Application Publication No. 2001-316821) discloses a standalone article containing low resistivity silicon carbide with a resistivity of less than 0.9 Ω·cm by chemical vapor deposition. As a specific example, it discloses a silicon carbide deposit with a resistivity of 0.25 to 0.9 Ω·cm.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent No. 4595153

[0010] Patent document 2: Japanese Patent Application Publication No. 2001-316821. Summary of the Invention

[0011] However, as a SiC molded body, a polycrystalline SiC molded body with a small crystal grain size is required. Typical wear preferentially begins at the grain boundaries, resulting in fewer particles generated during wear; therefore, a small crystal grain size is preferred. Furthermore, if the volume resistivity of the polycrystalline SiC molded body can be reduced, it is preferred for use as a component in semiconductor manufacturing equipment, such as a heater.

[0012] However, when the crystal grain size is small, the reduction in volume resistivity is limited due to the decrease in the mean free path of charge carriers and the increase in the amount of grain boundaries that constitute the conductive resistance component.

[0013] Therefore, the purpose of this invention is to provide a polycrystalline SiC molded body with small crystal grain size and low volume resistivity, and a method for manufacturing the same.

[0014] Through research, the inventors discovered that the above problems can be solved in the following way.

[0015] [1] A polycrystalline SiC molded body, wherein the average crystal grain size is less than 5 μm and the nitrogen concentration is 2.7 × 10⁻⁶. 19 ~5.4×10 20 (pieces / cm) 3 The product of carrier density and Hall mobility is 4.0 × 10⁻⁶. 20 ~6.0×10 21 (units / cmVsec).

[0016] [2] The polycrystalline SiC molded body according to [1], wherein the volume resistivity is less than 0.020 Ω·cm.

[0017] [3] A method for manufacturing a polycrystalline SiC molded body, wherein the polycrystalline SiC molded body is the polycrystalline SiC molded body described in [1] or [2], the manufacturing method comprising: a step of placing a substrate in a CVD reactor; a step of heating the substrate; and a step of introducing a mixed gas containing a raw material gas and a nitrogen-containing gas into the CVD reactor, and forming a polycrystalline SiC film on the heated substrate by CVD. The step of forming the polycrystalline SiC film is performed under the following condition: the arrival time τ, which represents the time from the introduction of the mixed gas into the CVD reactor until it reaches the substrate, is 1.6 to 6.7 seconds.

[0018] [4] According to the manufacturing method described in [3], the step of forming a polycrystalline SiC film is carried out at a film formation rate of 400 to 1300 μm / hr.

[0019] [5] The manufacturing method according to [3] or [4], wherein the reaction temperature of the substrate is 1300 to 1400 °C.

[0020] According to the present invention, a polycrystalline SiC molded body with small crystal grain size and low volume resistivity and a method thereof can be provided. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating an example of a manufacturing system for polycrystalline SiC molded bodies.

[0022] Figure 2 This is a schematic diagram showing a modified example of a CVD reactor. Detailed Implementation

[0023] 1. Polycrystalline SiC molded body

[0024] The polycrystalline SiC molded body of this invention has an average crystal grain size of less than 5 μm and a nitrogen concentration of 2.7 × 10⁻⁶. 19 ~5.4×10 20 (pieces / cm) 3 The product of carrier density and Hall mobility is 4.0 × 10⁻⁶. 20 ~6.0×10 21 (pieces / cmVsec). Using this structure, it is possible to obtain polycrystalline SiC molded bodies with small crystal grain size but sufficiently low volume resistivity.

[0025] In this specification, "average crystal grain size" refers to the median grain size determined by EBSD (Electron Backscatter Diffraction) (region method).

[0026] Polycrystalline SiC molded bodies with an average crystal grain size of 5 μm or less can be considered polycrystalline SiC molded bodies with small grain sizes. Such polycrystalline SiC molded bodies generally have difficulty achieving low volume resistivity. However, according to this embodiment, although the average crystal grain size is 5 μm or less, a sufficiently low volume resistivity can be obtained.

[0027] The average crystal grain size is, for example, 0.5 to 5 μm, preferably 1.0 to 5 μm.

[0028] In this specification, "nitrogen concentration" refers to the number of nitrogen atoms per unit volume (atoms / cm³). 3 The nitrogen concentration was determined using dynamic SIMS (dynamic secondary ion mass spectrometry).

[0029] Nitrogen concentration is 2.7 × 10⁻⁶ 19 ~5.4×10 20 (pieces / cm) 3 This allows for a sufficiently low volume resistivity. It should be noted that this nitrogen concentration corresponds to 200–3800 ppm.

[0030] Such a nitrogen concentration is extremely high for an impurity incorporated into a polycrystalline SiC molded body, typically exceeding the solid solubility limit. Adding nitrogen in amounts exceeding the solid solubility limit results in compounds different from SiC, failing to fulfill the required function of a polycrystalline SiC molded body. However, according to this embodiment, the manufacturing method described later allows for the solid dissolution of nitrogen despite its concentration, thereby satisfying the required properties for the polycrystalline SiC molded body. The reason for achieving these properties is not yet clear, but the inventors believe that since impurities generally tend to accumulate at grain boundaries, a larger amount of nitrogen can be incorporated without hindering the properties, thus achieving these properties.

[0031] The product of carrier density and Hall mobility is based on the formula "carrier density (numbers / cm³)". 3 ")" and "Hall mobility (cm)" 2 The value obtained by " / Vsec)".

[0032] The product of carrier density and Hall mobility is related to volume resistivity. According to this embodiment, the product of carrier density and Hall mobility is 4.0 × 10⁻⁶. 20 ~6.0×10 21 (units / cmVsec), thus enabling the achievement of sufficiently small volume resistivity.

[0033] Carrier density (numbers / cm³) 3 ")" refers to the concentration of impurities incorporated into the SiC molded body. The carrier density can be determined using the Hall effect test.

[0034] For example, the carrier density is 1.0 × 10⁻⁶. 19 ~6.0×10 19 (pieces / cm) 3 ).

[0035] Hall mobility (cm) 2 " / Vsec" is a well-known parameter that can be determined using Hall effect testing. For example, Hall mobility ranges from 10.0 to 150 (cm²). 2 / Vsec).

[0036] According to this embodiment, the polycrystalline SiC molded body can, for example, have a volume resistivity of 0.020 Ω·cm or less, preferably 0.010 Ω·cm or less. Furthermore, the polycrystalline SiC molded body can, for example, have a volume resistivity of more preferably 0.0010 Ω·cm or less, and even more preferably 0.0005 Ω·cm or less. The volume resistivity of the polycrystalline SiC molded body can be measured using, for example, Loresta.

[0037] In a preferred embodiment, the polycrystalline SiC prototype is 3C-SiC.

[0038] In a preferred embodiment, the polycrystalline SiC molded body has a main surface. The polycrystalline SiC molded body is preferably plate-shaped, more preferably circular plate-shaped. In the case of a plate-shaped body, the main surface of the polycrystalline SiC molded body refers to the surface and back surface excluding the side surfaces. In this case, the thickness of the polycrystalline SiC molded body is, for example, 0.1–5.0 mm, preferably 0.2–3.0 mm. Furthermore, in the case of a circular plate-shaped body, the diameter of the polycrystalline SiC molded body is not particularly limited, for example, 100–300 mm, preferably 130–200 mm.

[0039] Polycrystalline SiC molded bodies can also be cylindrical. In the case of a cylindrical shape, the main surfaces of the polycrystalline SiC molded body refer to the surface and inner surface of the cylinder. In this case, the thickness of the polycrystalline SiC molded body is, for example, 0.1 to 5.0 mm, preferably 0.2 to 3.0 mm.

[0040] In a more preferred embodiment, the principal plane has an (111) peak intensity ratio of 0.6 or higher. The "(111) peak intensity ratio" is a parameter in the X-ray diffraction pattern that represents the ratio of the diffraction peak intensity of SiC (111) to the sum of the diffraction peak intensities of the SiC (111) plane, SiC (200) plane, SiC (220) plane, and SiC (311) plane. It should be noted that when the (111) peak intensity ratio varies depending on its position within the principal plane, the (111) peak intensity ratio is used as the average value.

[0041] That is, the polycrystalline SiC molded body has a (111) strong orientation. By having this crystal structure, it is possible to achieve a polycrystalline SiC molded body with sufficiently low volume resistivity. Although the reason for this property is not yet clear, it can be assumed that, for example, the strongly oriented crystal structure increases the carrier mobility compared to the randomly oriented structure, thus reducing the volume resistivity.

[0042] 2. Manufacturing method of polycrystalline SiC molded body

[0043] The polycrystalline SiC molded body with the above-mentioned characteristics can be obtained by adjusting the film formation conditions, etc., in the manufacturing method described below. The manufacturing method of the polycrystalline SiC molded body of this embodiment will be described below.

[0044] Figure 1 This is a schematic diagram illustrating an example of a manufacturing system used in the method for manufacturing a polycrystalline SiC molded body according to this embodiment. The manufacturing system includes a CVD reactor 1 and a mixer 2. In the mixer 2, a carrier gas, a raw material gas serving as a SiC supply source, and a nitrogen-containing gas are mixed to generate a mixed gas. The mixed gas is supplied from the mixer 2 to the CVD reactor 1 at a flow rate Q. A substrate 3 (e.g., a graphite substrate) is disposed within the CVD reactor 1. During operation in the CVD reactor 1, the substrate 3 is heated. The substrate 3 is preferably in the shape of a disc or rod. Furthermore, a nozzle 4 is provided within the CVD reactor 1, through which the mixed gas is introduced into the CVD reactor. After the mixed gas is introduced into the CVD reactor, a polycrystalline SiC film is formed on the heated substrate 3 by CVD. At this time, nitrogen from the nitrogen-containing gas is incorporated into the polycrystalline SiC film. That is, a nitrogen-doped polycrystalline SiC film can be obtained. The obtained polycrystalline SiC film is then removed from the substrate 3 and polished as needed. Thus, polycrystalline SiC molded bodies can be obtained.

[0045] in addition, Figure 1 In the example shown, multiple nozzles 4 are provided. Additionally, the substrate 3 is arranged longitudinally. The multiple nozzles 4 are positioned on both sides of the furnace wall, sandwiching the substrate 3 in the middle. Figure 1 In the figure, “L” represents the distance between the front end of each nozzle (the outlet of the raw material gas) and the substrate 3.

[0046] It should be noted that CVD reactor 1 is not limited to Figure 1 The structure shown. Figure 2 This is a diagram showing a modified example of CVD reactor 1. Figure 2 In the example shown, multiple nozzles 4 are arranged at the top of the CVD reactor 1. The substrate 3 is arranged laterally. The CVD reactor 1 can also be... Figure 2 The structure shown.

[0047] CVD reactor implementation methods can include cold-wall and hot-wall types. In a cold-wall CVD reactor, the furnace walls and internal atmosphere are not directly heated; only the substrate is heated. In a hot-wall CVD reactor, the entire furnace, including the furnace walls and internal atmosphere, is heated. In this embodiment, the characteristics of the SiC molded bodies obtained by the cold-wall and hot-wall methods are identical.

[0048] Furthermore, in this embodiment, the formation of the polycrystalline SiC film is carried out within a specific arrival time τ. Specifically, it is carried out under the condition that the arrival time τ is 1.6 to 6.7 seconds.

[0049] "Arrival time τ" represents the time from the introduction of the mixed gas into the CVD reactor until it reaches the substrate. Specifically, the arrival time τ is calculated according to the following equation 1.

[0050] (Equation 1) Arrival time τ=L / u

[0051] In Formula 1, “L”, as mentioned above, represents the distance between the raw material gas outlet (the front end of the nozzle) and the substrate.

[0052] “u” indicates the flow rate of the mixed gas in the reactor.

[0053] The velocity of the mixed gas ("u") is calculated by dividing the flow rate (Q) by the nozzle cross-sectional area (A).

[0054] Traffic "Q" Figure 1 As described in the description, the flow rate of the mixed gas between the mixer and the reactor is indicated. The flow rate (Q) is not particularly limited, but is, for example, 10 to 150 L / min, preferably 20 to 110 L / min.

[0055] According to the inventors' understanding, the arrival time τ affects the nitrogen concentration in the solid solution, and also influences the carrier density and Hall mobility. Therefore, by optimizing the arrival time τ, it is possible to achieve polycrystalline SiC films with small crystal grain size but low volume resistivity. The arrival time τ is preferably 1.6 to 6.7 seconds, and from the perspective of being able to adjust the grain size to an preferred range, it is more preferably 1.8 to 5.7 seconds, and even more preferably 2.0 to 5.0 seconds.

[0056] The feed gas used as a SiC supply source can be a single-component system (a gas containing Si and C) or a two-component system (a gas containing Si and a gas containing C).

[0057] For example, examples of feed gases for single-component systems include methyltrichlorosilane, phenyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, and trimethylchlorosilane. Additionally, examples of feed gases for two-component systems include mixtures of gases containing silanes such as trichlorosilane and silane with hydrocarbon gases.

[0058] As a nitrogen-containing gas, any gas capable of incorporating nitrogen into a polycrystalline SiC film is acceptable. For example, nitrogen gas can be used as a nitrogen-containing gas.

[0059] There are no particular restrictions on the carrier gas used during film formation; for example, hydrogen can be used.

[0060] There are no particular restrictions on film formation conditions other than arrival time τ; for example, the following conditions can be used.

[0061] Regarding the heating temperature during film formation, the substrate temperature is, for example, 1300–1400°C, preferably 1300–1350°C. It should be noted that the furnace walls and insulation materials inside the furnace are preferably kept at a temperature (e.g., below 1000°C, preferably below 700°C) where SiC and decomposition products of the raw material gases will not be deposited.

[0062] The flow rate of the nitrogen-containing gas is, for example, 5 vol% to 100 vol% relative to the total flow rate of the nitrogen-containing gas, the feed gas, and the carrier gas, preferably 30 vol% to 50 vol%.

[0063] The film formation rate is, for example, 400 to 1300 μm / hr, preferably 520 to 645 μm / hr.

[0064] The residence time is, for example, 5 to 40 seconds, preferably 10 to 30 seconds. Residence time refers to the time the mixed gas remains in the reactor.

[0065] Example

[0066] The present invention will be described in more detail below through examples. It should be noted that in these examples and comparative examples, the film-forming time is appropriately set from 1 to 5 hours, and the reaction temperature in the examples is appropriately set from 1300 to 1400°C. Furthermore, the reaction temperature in the comparative examples is appropriately set from 1200 to 1500°C.

[0067] (Example 1)

[0068] As a CVD reactor, it was prepared Figure 1 The reactor shown is equipped with a graphite substrate with a diameter of 160 mm and a thickness of 5 mm, which is placed inside the CVD reactor.

[0069] Then, under the conditions described in Table 1, a polycrystalline SiC film is formed on the substrate. Specifically, MTS (methyltrichlorosilane) is used as the feed gas. H2 gas is used as the carrier gas. N2 gas is used as the nitrogen-containing gas. The feed gas, carrier gas, and nitrogen-containing gas are mixed in mixer 2 to generate a mixed gas. The mixed gas is supplied to CVD reactor 1. The supply amount of the mixed gas is the value denoted as "Gas Amount" in Table 1. In addition, the concentrations of MTS gas, H2 gas, and N2 gas in the mixed gas are as described in Table 1. The reaction temperature (substrate temperature) is also as described in Table 1.

[0070] The dwell time is 13.4 seconds. The dwell time is calculated using the following formula.

[0071] (Equation 2): Residence time (seconds) = (furnace volume (L) / gas volume) × [(20 + 273) / (reaction temperature + 273)] × 60

[0072] The time τ to reach the substrate is 3.14 seconds.

[0073] After film formation, the graphite substrate was removed from the CVD furnace and subjected to peripheral processing and cutting. Next, the graphite substrate was removed to obtain a polycrystalline SiC molded body with a diameter of 150 mm and a thickness of 0.6 mm. Then, a planar grinding process was performed to obtain a polycrystalline SiC molded body with a diameter of 150 mm and a thickness of 0.4 mm. This was obtained as the polycrystalline SiC molded body of Example 1.

[0074] (Examples 2-7 and Comparative Examples 1-3)

[0075] A polycrystalline SiC film was formed in the same manner as in Example 1. However, the film formation conditions were changed as shown in Table 1.

[0076] (Assessment Methodology)

[0077] For the obtained polycrystalline SiC molded body, the intensity ratio of the (111) peak, carrier density, Hall mobility, nitrogen concentration (SIMS N concentration), average crystal grain size, and resistivity were determined. The methods for determining each value are shown below.

[0078] (111) Peak intensity ratio

[0079] Using an XRD-6000 manufactured by Shimadzu Corporation of Japan, the X-ray diffraction pattern of the center of a polycrystalline SiC molded body based on the 2θ / θ method was determined under the following conditions.

[0080] copper target

[0081] Voltage: 40.0kV

[0082] Current: 20.0mA

[0083] Diverging slit: 1.00000 deg.

[0084] Scattering slit: 1.00000 deg.

[0085] Receiving slit: 0.30000mm

[0086] Scan range: 20,000–80,000 deg.

[0087] Scan speed: 4.0000 deg. / min.

[0088] Sampling interval: 0.0200deg.

[0089] Preset time: 0.30 seconds.

[0090] In the obtained X-ray diffraction pattern, the average value of the diffraction peak intensity in the range of 20.0 to 80.0 degrees was used as the background correction value, and the diffraction peak intensity in the range of 35.3 to 36.0 degrees was used as the peak intensity of the SiC(111) surface of 3C-SiC.

[0091] Similarly, the diffraction peak intensities in the range of 41.1 to 41.8 degrees with a diffraction angle of 2θ are used as the peak intensities of the SiC(200) surface.

[0092] Similarly, the diffraction peak intensities in the range of 59.7–60.3 degrees with a diffraction angle of 2θ are used as the peak intensities of the SiC(220) surface.

[0093] Similarly, the diffraction peak intensities in the range of 71.5–72.3 degrees with a diffraction angle of 2θ are used as the peak intensities of the SiC(311) surface.

[0094] Next, the sum of the diffraction peak intensities of the SiC(111) plane, SiC(200) plane, SiC(220) plane, and SiC(311) plane is calculated. Then, the ratio of the diffraction peak intensity of SiC(111) to the sum is used as the (111) peak intensity ratio (X0) to be calculated.

[0095] (Carrier density)

[0096] Using a Resitest8200 manufactured by Toyo Technology Co., Ltd. of Japan, the Hall voltage and resistivity based on the VanderPauw method were determined, and the carrier density and Hall mobility were calculated (Hall effect test). The Hall effect test was performed under the following conditions after the sample was cut into approximately 10mm × 10mm × 0.5mm pieces and In electrodes were formed.

[0097] Applying magnetic field: 1T

[0098] Applied current: 1.0 × 10 -6 A

[0099] Measurement temperature: room temperature (295K)

[0100] (Nitrogen concentration)

[0101] The nitrogen content in polycrystalline SiC molded bodies was measured using a SIMS-4000 manufactured by Atomika.

[0102] (Average crystal grain size)

[0103] Using DigiView manufactured by TSL Solutions, Inc., the EBSD orientation map of the main surface normal direction ±10° (hereinafter referred to as "ND direction") of the polycrystalline SiC molded body was measured.

[0104] The conditions for determining the EBSD orientation mapping are shown below.

[0105] Pretreatment: Mechanical grinding, carbon vapor deposition

[0106] Equipment: FE-SEM, SU-70 manufactured by Hitachi High-Tech Co., Ltd.

[0107] DigiView produced by TSL Solutions, EBSD Co., Ltd.

[0108] Measurement conditions: Voltage: 20kV

[0109] Radial angle: 70°

[0110] Measurement area: 100μm × 100μm

[0111] Measurement interval: 0.03 μm

[0112] Crystal system of the evaluated object: 3C type SiC (space group 216)

[0113] Using the EBSD orientation map determined above, for all individual regions within the entire region (100μm×100μm), the sum of the values ​​obtained by dividing the area of ​​the individual region by the total area of ​​the observation region and then multiplying the sum by the area of ​​the individual region is calculated.

[0114] (Examination of results)

[0115] The results are shown in Table 2.

[0116] As shown in Table 1, the polycrystalline SiC molded bodies of Examples 1-7 were polycrystalline SiC molded bodies formed under conditions where the time τ to reach the substrate was in the range of 1.6 to 6.7 seconds. As shown in Table 2, the polycrystalline SiC molded bodies of Examples 1-7 exhibited low volume resistivity. In particular, Examples 1-5 showed extremely low volume resistivity (specifically, below 0.011 Ω·cm). The average crystal grain size of these polycrystalline SiC molded bodies of Examples 1-7 was below 5 μm, confirming them as polycrystalline SiC molded bodies with small crystal grain size. Furthermore, the nitrogen concentration was 2.7 × 10⁻⁶. 19 ~5.4×10 20 (pieces / cm) 3 The product of carrier density and Hall mobility is 4.0 × 10⁻⁶. 20 ~6.0×10 21(number / cmVsec). (111) Peak intensity ratio is above 0.6.

[0117] On the other hand, in Comparative Example 1, where the time τ to reach the substrate was 1.5 seconds, the volume resistivity was 0.022 Ω·cm, which was greater than that of Examples 1 to 7.

[0118] Furthermore, in Comparative Example 2, where the time to reach the substrate was 0.03 seconds, the volume resistivity was 0.016 Ω·cm, which was still relatively high. Additionally, the average crystal grain size was 11 μm, which was larger than that of Examples 1-7.

[0119] In addition, in Comparative Example 3, where the time to reach the substrate was 7.0 seconds, the volume resistivity was 0.007 Ω·cm and the average crystal grain size exceeded 5 μm.

[0120] Table 1

[0121]

[0122] Table 2

[0123]

[0124] Symbol Explanation

[0125] 1CVD reactor

[0126] 2 mixers

[0127] 3 substrates

[0128] 4 nozzles.

Claims

1. A polycrystalline SiC molded body, wherein, The average crystal grain size is less than 5 μm. The nitrogen concentration is 2.7 × 10⁻⁶. 19 ~5.4×10 20 pcs / cm 3 , The product of carrier density and Hall mobility is 4.0 × 10⁻⁶. 20 ~6.0×10 21 indivual / , Volume resistivity the following.

2. A method for manufacturing a polycrystalline SiC molded body, wherein, The polycrystalline SiC molded body is the polycrystalline SiC molded body according to claim 1, and the manufacturing method includes: The steps for preparing the substrate in a CVD reactor; The step of heating the substrate; and The step of introducing a mixed gas containing raw material gas and nitrogen-containing gas into the CVD reactor, and forming a polycrystalline SiC film on the heated substrate using the CVD method. The step of forming the polycrystalline SiC film is carried out under the following conditions: the arrival time τ, which represents the time from the introduction of the mixed gas into the CVD reactor until it reaches the substrate, is 1.6 to 6.7 seconds.

3. The manufacturing method according to claim 2, wherein, The step of forming the polycrystalline SiC film is carried out at a film formation rate of 400–1300 μm / hr.

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