Hetero-epitaxial single-crystal silicon substrate, epitaxial substrate, semiconductor device, and method for manufacturing a hetero-epitaxial single-crystal silicon substrate

Abstract

Provided are a single crystal silicon substrate for heteroepitaxy, an epitaxial substrate, a semiconductor device, and a method for manufacturing a single crystal silicon substrate for heteroepitaxy, which can suppress the occurrence of warpage and cracking when a heteroepitaxial layer is grown. 【Solution means】A single crystal silicon substrate for heteroepitaxy for growing a heteroepitaxial layer on a surface, satisfying one or more of the following four conditions. Condition 1: The dopant content is 1.0×10 16 atoms / cm 3 or more Condition 2: The oxygen content is 5.0×10 17 atoms / cm 3 or more Condition 3: The nitrogen content is 5.0×10 15 atoms / cm 3 or more Condition 4: The carbon content is 5.0×10 15 atoms / cm 3 or more

Description

[Technical Field]

[0001] The present invention relates to a single-crystal silicon substrate for heteroepitaxial applications, an epitaxial substrate, a semiconductor device, and a method for manufacturing a single-crystal silicon substrate for heteroepitaxial applications. [Background technology]

[0002] Heteroepitaxial technology, which involves epitaxially growing heteroepitaxial materials such as diamond or GaN on a silicon substrate, is a highly effective method because it allows for the growth of expensive materials on inexpensive silicon substrates, enabling low-cost and large-diameter applications. However, because it involves growing materials different from silicon, the lattice constants and coefficients of thermal expansion differ between silicon and the epitaxial material. This can cause stress in the substrate after epitaxial growth, leading to dislocations. These dislocations can then bundle together and slip, potentially causing the substrate to warp, and in the worst-case scenario, cracking and breakage.

[0003] One technique to suppress substrate warping and cracking is to increase the thickness of the silicon substrate. However, other techniques have also been attempted to suppress substrate warping and cracking by focusing on the silicon substrate itself and utilizing its properties. For example, Patent Document 1 describes a method for growing a polycrystalline diamond layer with a thickness of 100 μm or more on a single-crystal silicon substrate using chemical vapor deposition, with diamond particles attached to the single-crystal silicon substrate as the nucleus. 17 atoms / cm 3 The use of substrates with the following oxygen concentrations is disclosed.

[0004] Another method involves using a silicon substrate suitable for forming inexpensive nitride semiconductors based on silicon substrates, with a boron concentration of 10 to 10 times that of nitrogen. 7A nitride semiconductor formation substrate has been proposed that reduces the occurrence of warping and cracking caused by differences in lattice constants and thermal expansion coefficients between materials, even when a thick nitride semiconductor epitaxial layer is grown with double the concentration, and exhibits excellent mechanical and thermal strength (Patent Document 2).

[0005] Another method is to assume an oxygen concentration of 1.0 × 10⁻⁶ 16 atoms / cm 3 It has been proposed to sequentially laminate silicon carbide thin films and diamond thin films on a low-oxygen single-crystal silicon substrate (Patent Document 3). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-102598 [Patent Document 2] Japanese Patent Publication No. 2022-124012 [Patent Document 3] Japanese Patent Publication No. 2002-261011 [Overview of the project] [Problems that the invention aims to solve]

[0007] Thus, while there are technologies that focus on light elements as silicon substrates for heteroepitaxial galvanizing on silicon substrates, actual silicon substrates contain carbon in addition to oxygen, boron, and nitrogen as described in prior art literature. Therefore, the characteristics of silicon substrates for heteroepitaxial galvanizing cannot be defined solely by prior art.

[0008] The present invention has been made to solve the above problems and aims to provide a heteroepitaxial single-crystal silicon substrate, an epitaxial substrate, a semiconductor device, and a method for manufacturing a heteroepitaxial single-crystal silicon substrate that can suppress warping and cracking when a heteroepitaxial layer is grown. [Means for solving the problem]

[0009] The present invention has been made to achieve the above object, and relates to a silicon substrate used for diamond growth on a silicon single crystal substrate or heteroepitaxial growth of GaN, AlN, etc. More specifically, it is a technology for optimizing light elements in a silicon substrate to suppress warping and cracking of the silicon substrate during heteroepitaxial growth. More specifically, the present invention provides a single crystal silicon substrate for heteroepitaxy for growing a heteroepitaxial layer on a surface, characterized by satisfying one or more of the following four conditions. Condition 1: Dopant content is 1.0×10 16 atoms / cm 3 or more Condition 2: Oxygen content is 5.0×10 17 atoms / cm 3 or more Condition 3: Nitrogen content is 5.0×10 15 atoms / cm 3 or more Condition 4: Carbon content is 5.0×10 15 atoms / cm 3 or more

[0010] In this configuration, since the single crystal silicon substrate for heteroepitaxy contains dopants, oxygen, nitrogen, and carbon so as to satisfy one or more of Conditions 1 to 4, when heteroepitaxial growth is performed on the substrate, the dislocations generated in the substrate are blocked by the elements that satisfy the content specified in any of Conditions 1 to 4 from expanding into the epitaxial layer. That is, the extension of dislocations is suppressed by one or more of the elements dopant, oxygen, nitrogen, and carbon, and as a result, the progress of slip is also suppressed. Therefore, when a heteroepitaxial layer is grown, warping and cracking can be suppressed. Here, the dopant refers to impurities such as boron, Al, Ga, indium, phosphorus, arsenic, and antimony added to control the resistivity of single crystal silicon.

[0011] The dopant may also be boron. When the dopant is boron, the heteroepitaxial single-crystal silicon substrate becomes a p-type semiconductor. Furthermore, the resistivity of the substrate can be controlled by adjusting the boron content.

[0012] Furthermore, the present invention provides an epitaxial substrate comprising the heteroepitaxial single-crystal silicon substrate described above and the heteroepitaxial layer formed on the surface of the heteroepitaxial single-crystal silicon substrate.

[0013] In this configuration, the heteroepitaxial single-crystal silicon substrate of the epitaxial substrate contains dopants, oxygen, nitrogen, and carbon in amounts that satisfy one or more of conditions 1 to 4. Therefore, when heteroepitaxial growth is performed on the substrate, the elements that meet the content requirements of any of conditions 1 to 4 prevent dislocations generated on the substrate from spreading to the epitaxial layer. Therefore, warping and cracking that occur when growing heteroepitaxial layers are suppressed.

[0014] The material constituting the heteroepitaxial layer may be any one of GaN, AlN, or diamond. By using GaN as the material constituting the heteroepitaxial layer, the semiconductor device formed will have a higher dielectric breakdown voltage and a faster electron saturation rate than a silicon semiconductor device. By using AlN or diamond as the material constituting the heteroepitaxial layer, the semiconductor device formed will have an extremely high dielectric breakdown voltage compared to a silicon semiconductor device.

[0015] Furthermore, the present invention provides a semiconductor device characterized by comprising the epitaxial substrate described above.

[0016] In this configuration, since the semiconductor device is equipped with the epitaxial substrate described above, dislocations generated in the substrate during heteroepitaxial growth are prevented from expanding into the epitaxial layer, thereby suppressing warping and cracking. As a result, warping and cracking are suppressed, resulting in a highly reliable semiconductor device.

[0017] Furthermore, the present invention relates to a single crystal manufacturing process for producing single crystal silicon that satisfies one or more of the following four conditions, Condition 1: Dopant content is 1.0 × 10 16 atoms / cm 3 That's all. Condition 2: Oxygen content is 5.0 × 10 17 atoms / cm 3 That's all. Condition 3: Nitrogen content is 5.0 × 10 15 atoms / cm 3 That's all. Condition 4: Carbon content is 5.0 × 10 15 atoms / cm 3 That's all. The present invention provides a method for manufacturing a heteroepitaxial single-crystal silicon substrate, comprising a substrate manufacturing step for manufacturing a heteroepitaxial single-crystal silicon substrate from the single-crystal silicon manufactured in the single-crystal manufacturing step.

[0018] In this configuration, when manufacturing a single-crystal silicon substrate for heteroepitaxial growth, the single-crystal manufacturing process produces single-crystal silicon that satisfies one or more of the conditions 1 to 4 regarding the content of dopants, oxygen, nitrogen, and carbon. Therefore, when heteroepitaxial growth is performed on the single-crystal silicon substrate for heteroepitaxial growth produced from this single-crystal silicon, the elements that satisfy the content specified in any of the conditions 1 to 4 prevent dislocations generated in the substrate from spreading to the epitaxial layer. Therefore, it is possible to suppress warping and cracking that occur when growing heteroepitaxial layers. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a heteroepitaxial single-crystal silicon substrate, an epitaxial substrate, a semiconductor device, and a method for manufacturing a heteroepitaxial single-crystal silicon substrate that can suppress warping and cracking when a heteroepitaxial layer is grown. Furthermore, the configuration of the present invention makes it possible to suppress warping and cracking when growing heteroepitaxial layers, thus enabling heteroepitaxial growth on large-diameter silicon substrates. [Brief explanation of the drawing]

[0020] [Figure 1] The schematic configuration of a heteroepitaxial single-crystal silicon substrate and an epitaxial substrate according to an embodiment of the present invention is shown. [Figure 2] The following outlines a method for manufacturing a heteroepitaxial single-crystal silicon substrate according to an embodiment of the present invention. [Figure 3] The following is a list of the content of various light elements and the slip length in the heteroepitaxial single-crystal silicon substrates in the examples. [Modes for carrying out the invention]

[0021] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0022] As described above, there was a need for a heteroepitaxial single-crystal silicon substrate, an epitaxial substrate, a semiconductor device, and a method for manufacturing a heteroepitaxial single-crystal silicon substrate that could suppress warping and cracking when growing a heteroepitaxial layer.

[0023] As a result of diligent research into the above-mentioned problems, the inventors, unlike the prior art, have taken a comprehensive approach to understanding the characteristics of silicon substrates and have sought a configuration required for a silicon single-crystal substrate suitable for heteroepitaxial applications. As a result, we discovered that a heteroepitaxial single-crystal silicon substrate for growing a heteroepitaxial layer on its surface, characterized by satisfying one or more of the following four conditions, can suppress warping and cracking when a heteroepitaxial layer is grown using such a substrate, thus completing the present invention. Condition 1: Dopant content is 1.0 × 10 16 atoms / cm 3 That's all. Condition 2: Oxygen content is 5.0 × 10 17 atoms / cm 3 That's all. Condition 3: Nitrogen content is 5.0 × 10 15 atoms / cm 3 That's all. Condition 4: Carbon content is 5.0 × 10 15 atoms / cm 3 That's all.

[0024] Furthermore, we have discovered that a high-quality epitaxial substrate can be provided that suppresses warping and cracking by an epitaxial substrate comprising the heteroepitaxial single-crystal silicon substrate described above and the heteroepitaxial layer formed on the surface of the heteroepitaxial single-crystal silicon substrate, thereby completing the present invention.

[0025] Furthermore, we have discovered that a semiconductor device characterized by comprising the epitaxial substrate described above can provide a high-quality and reliable semiconductor device in which warping and cracking are suppressed, thus completing the present invention.

[0026] Furthermore, a single crystal manufacturing process for producing single crystal silicon that satisfies one or more of the following four conditions, Condition 1: Dopant content is 1.0 × 10 16 atoms / cm 3 That's all. Condition 2: Oxygen content is 5.0 × 10 17 atoms / cm 3 That's all. Condition 3: Nitrogen content is 5.0 × 1015 atoms / cm 3 That's all. Condition 4: Carbon content is 5.0 × 10 15 atoms / cm 3 That's all. The present invention was completed by discovering that a method for manufacturing a heteroepitaxial single-crystal silicon substrate, characterized by including a substrate manufacturing step for manufacturing a heteroepitaxial single-crystal silicon substrate from the single-crystal silicon manufactured in the single-crystal manufacturing step, can suppress warping and cracking when a heteroepitaxial layer is grown on the surface of the obtained heteroepitaxial single-crystal silicon substrate.

[0027] Embodiments of the present invention will be described below with reference to the drawings. First, with reference to Figure 1, the configuration of the heteroepitaxial single-crystal silicon substrate 1 according to an embodiment of the present invention will be described.

[0028] As shown in Figure 1, the heteroepitaxial single-crystal silicon substrate 1 is a single-crystal silicon substrate for growing a heteroepitaxial layer 3 on its surface. The dimensions and shape of the heteroepitaxial single-crystal silicon substrate 1 can be appropriately selected according to the material, dimensions, and shape of the heteroepitaxial layer 3 to be grown, but a disc-shaped wafer can be used as an example.

[0029] The heteroepitaxial single-crystal silicon substrate 1 satisfies one or more of the following four conditions. Preferably, it satisfies two or more conditions, more preferably three, or all four conditions. Condition 1: Dopant content is 1.0 × 10 16 atoms / cm 3 That's all. Condition 2: Oxygen content is 5.0 × 10 17 atoms / cm 3 That's all. Condition 3: Nitrogen content is 5.0 × 10 15 atoms / cm 3 That's all. Condition 4: Carbon content is 5.0 × 10 15atoms / cm 3 That's all. The following explains these conditions.

[0030] Condition 1 is when the dopant content is 1.0 × 10⁻⁶ 16 atoms / cm 3 The above is the specified condition. In known single-crystal silicon substrates, dopants are included to control resistivity or the type of majority carrier, such as n-type or p-type. However, the heteroepitaxial single-crystal silicon substrate 1 of the present invention contains dopants within the range that satisfies condition 1, thereby suppressing warping and cracking when the heteroepitaxial layer 3 is grown. Specifically, by satisfying condition 1, when heteroepitaxial growth is performed on a heteroepitaxial single-crystal silicon substrate 1 to produce a heteroepitaxial layer 3, even if dislocations occur in the heteroepitaxial single-crystal silicon substrate 1 due to differences in lattice constants and thermal expansion coefficients between silicon and the material constituting the heteroepitaxial layer 3, the dopant prevents the generated dislocations from expanding into the heteroepitaxial layer 3. This suppresses the formation of dislocations into slips, and prevents warping and cracking from occurring starting from these slips.

[0031] The dopant can be any known element used to control the resistivity of a silicon substrate. For example, a light element such as boron can be used. When the dopant is boron, the heteroepitaxial single-crystal silicon substrate 1 becomes a p-type semiconductor. Furthermore, the resistivity of the substrate can be controlled by adjusting the boron content. Examples of dopants other than boron include indium, which can make the heteroepitaxial single-crystal silicon substrate 1 a p-type semiconductor, and phosphorus, arsenic, and antimony, which can make the heteroepitaxial single-crystal silicon substrate 1 an n-type semiconductor.

[0032] Condition 2 is an oxygen content of 5.0 × 10 17 atoms / cm 3The above is the specified condition. Oxygen improves the mechanical strength of silicon single crystals and also affects resistivity, but the heteroepitaxial single crystal silicon substrate 1 of the present invention contains oxygen within the range that satisfies condition 2, thereby suppressing warping and cracking when the heteroepitaxial layer 3 is grown. Specifically, by satisfying condition 2, even if dislocations occur in the heteroepitaxial single-crystal silicon substrate 1 when generating the heteroepitaxial layer 3, oxygen prevents the generated dislocations from expanding into the epitaxial layer, thereby suppressing warping and cracking, similar to the case where condition 1 is satisfied. In this case, the standard for oxygen concentration (content) shall conform to ASTM'79 (American Society for Testing and Materials).

[0033] Condition 3 is a nitrogen content of 5.0 × 10 15 atoms / cm 3 The above is what is stipulated. Nitrogen is sometimes included in known silicon substrates to suppress the occurrence of crystal defects or to control oxygen precipitates in single-crystal silicon substrates. However, the heteroepitaxial single-crystal silicon substrate 1 of the present invention contains nitrogen within a range that satisfies condition 3, thereby suppressing warping and cracking when the heteroepitaxial layer 3 is grown. Specifically, by satisfying condition 3, even if dislocations occur in the heteroepitaxial single-crystal silicon substrate 1 when generating the heteroepitaxial layer 3, the nitrogen prevents the generated dislocations from expanding into the epitaxial layer, thereby suppressing warping and cracking, similar to the case where condition 1 is satisfied.

[0034] Condition 4 is a carbon content of 5.0 × 10 15 atoms / cm 3 The above is what is stipulated. While carbon is naturally introduced during the single-crystal manufacturing process in known single-crystal silicon substrates, the heteroepitaxial single-crystal silicon substrate 1 of the present invention contains carbon within a range that satisfies condition 4, thereby suppressing warping and cracking when the heteroepitaxial layer 3 is grown. Specifically, by satisfying condition 4, even if dislocations occur in the heteroepitaxial single-crystal silicon substrate 1 when generating the heteroepitaxial layer 3, similar to the case where condition 1 is satisfied, the carbon prevents the generated dislocations from expanding into the epitaxial layer, thereby suppressing warping and cracking.

[0035] The heteroepitaxial single-crystal silicon substrate 1 only needs to satisfy one or more of conditions 1 to 4, but satisfying two or more conditions provides a stronger effect in suppressing warping and cracking. More preferably, it satisfies three or more conditions, and most preferably four conditions. In other words, by individually or in combination, adjusting the dopant, oxygen, nitrogen, and carbon content to the conditions specified in conditions 1 to 4, which are the content levels in which the effect is clearly observed, it is possible to make the heteroepitaxial single-crystal silicon substrate 1 into a heteroepitaxial substrate that is more effective in suppressing warping and cracking.

[0036] The dopant, oxygen, nitrogen, and carbon content in the heteroepitaxial single-crystal silicon substrate 1 can be measured using known measurement methods such as FT-IR (Fourier transform infrared spectroscopy) or SIMS (secondary ion mass spectrometry).

[0037] Furthermore, there is no particular upper limit to the content of the elements specified in conditions 1 to 4, but it should be, for example, the solid solubility limit for silicon, or the upper limit within the range that does not inhibit heteroepitaxial growth.

[0038] Thus, the heteroepitaxial single-crystal silicon substrate 1 of the present invention satisfies one or more of conditions 1 to 4. Therefore, even if dislocations occur in the heteroepitaxial single-crystal silicon substrate 1 when the heteroepitaxial layer 3 is formed, the resulting dislocations can be prevented from expanding into the epitaxial layer, thereby suppressing warping and cracking. The above is a description of the heteroepitaxial single-crystal silicon substrate 1 of the present invention.

[0039] Next, the configuration of the epitaxial substrate 5 of the present invention will be described with reference to Figure 1. As shown in Figure 1, the epitaxial substrate 5 comprises a heteroepitaxial single-crystal silicon substrate 1 and a heteroepitaxial layer 3 formed on the surface of the heteroepitaxial single-crystal silicon substrate 1.

[0040] The heteroepitaxial single-crystal silicon substrate 1 is a silicon single-crystal substrate that satisfies one or more of conditions 1 to 4, as described in the description of the structure of the heteroepitaxial single-crystal silicon substrate 1. The heteroepitaxial layer 3 is a layer formed on the surface of the heteroepitaxial single-crystal silicon substrate 1 by heteroepitaxial growth. The heteroepitaxial layer 3 can be made of a material different from silicon and can be heteroepitaxially grown on the surface of the heteroepitaxial single-crystal silicon substrate 1. Examples of such materials include GaN, AlN, and diamond.

[0041] By using GaN as the material constituting the heteroepitaxial layer 3, the resulting semiconductor device will have a higher dielectric breakdown voltage and faster electron saturation rate than a silicon semiconductor device. By using AlN or diamond as the material constituting the heteroepitaxial layer 3, the resulting semiconductor device will have an extremely high dielectric breakdown voltage compared to a silicon semiconductor device.

[0042] Furthermore, known methods such as vapor phase growth can be used to grow the heteroepitaxial layer 3.

[0043] Thus, in the present invention, the epitaxial substrate 5 contains a single-crystal silicon substrate 1 for heteroepitaxial growth in a quantity of dopant, oxygen, nitrogen, and carbon that satisfies one or more of conditions 1 to 4. Therefore, any element that satisfies conditions 1 to 4 prevents dislocations generated on the substrate during heteroepitaxial growth from spreading to the epitaxial layer. Therefore, the epitaxial substrate 5 is designed to suppress warping and cracking when the heteroepitaxial layer 3 is grown on it. The above describes the configuration of the epitaxial substrate 5 of the present invention.

[0044] Next, the configuration of the semiconductor device 7 of the present invention will be described with reference to Figure 1. As shown in Figure 1, the semiconductor device 7 of the present invention includes an epitaxial substrate 5. The configuration of the epitaxial substrate 5 is as described in the description of the configuration of the epitaxial substrate 5. A semiconductor device 7 is formed by creating a device on the heteroepitaxial layer 3 of this epitaxial substrate 5 and shaping it to the desired dimensions and form by dicing or other methods as needed.

[0045] Thus, because the semiconductor device 7 of the present invention includes an epitaxial substrate 5, dislocations generated in the substrate during heteroepitaxial growth are prevented from spreading to the heteroepitaxial layer 3, thereby suppressing warping and cracking. As a result, warping and cracking are suppressed, resulting in a high-quality and reliable semiconductor device 7. The above is a description of the configuration of the semiconductor device 7 of the present invention.

[0046] Next, with reference to Figure 2, an overview of the manufacturing method for the heteroepitaxial single-crystal silicon substrate 1 will be described. First, single-crystal silicon that satisfies one or more of the following four conditions is manufactured (S1 in Figure 2, single-crystal manufacturing process). Condition 1: Dopant content is 1.0 × 10 16 atoms / cm 3 That's all. Condition 2: Oxygen content is 5.0 × 10 17 atoms / cm 3 That's all. Condition 3: Nitrogen content is 5.0 × 10 15 atoms / cm 3 That's all. Condition 4: Carbon content is 5.0 × 10 15 atoms / cm 3 That's all.

[0047] As a specific manufacturing method, a cylindrical single-crystal silicon ingot can be produced using known manufacturing methods such as the Czochralski process or the band melting process. In the single crystal manufacturing process, dopants, oxygen, nitrogen, and carbon are added to the raw silicon in predetermined amounts as needed to ensure that the manufactured single crystal silicon satisfies one or more of conditions 1 to 4. However, when manufacturing single crystal silicon using the Czochralski process, oxygen is introduced from the quartz crucible, so it is not always necessary to add it to the raw material. The oxygen content can be adjusted by controlling the crucible rotation speed and convection during single crystal growth. Furthermore, since carbon is also introduced during the single crystal manufacturing process, it is not always necessary to add it to the raw materials. However, adding it to the raw materials allows for the introduction of a larger amount of carbon into the single crystal with high precision.

[0048] Once the single crystal manufacturing process is complete, the next step is to manufacture a heteroepitaxial single crystal silicon substrate 1 from the single crystal silicon produced in the single crystal manufacturing process (S2 in Figure 2, substrate manufacturing process). Specifically, the outer circumference of a round rod-shaped single-crystal silicon is ground to a uniform diameter, and then the single-crystal silicon is cut perpendicular to the axis of the rod using a wire saw or similar tool to form a disc shape. Further surface shaping is performed by etching and surface polishing to complete the heteroepitaxial single-crystal silicon substrate 1.

[0049] In the manufacturing method of the present invention, when producing the heteroepitaxial single-crystal silicon substrate 1, the single-crystal manufacturing process produces single-crystal silicon that satisfies one or more of the conditions 1 to 4 regarding the content of dopants, oxygen, nitrogen, and carbon. Therefore, when heteroepitaxial growth is performed on the heteroepitaxial single-crystal silicon substrate 1 produced by cutting from this single-crystal silicon, the elements that satisfy any of the conditions 1 to 4 prevent dislocations generated in the substrate from expanding into the heteroepitaxial layer 3. Therefore, it is possible to suppress warping and cracking when the heteroepitaxial layer 3 is grown. The above is an overview of the manufacturing method for the heteroepitaxial single-crystal silicon substrate 1. [Examples]

[0050] The present invention will be described in detail below, but the present invention is not limited to these descriptions. A heteroepitaxial single-crystal silicon substrate 1 satisfying one or more of conditions 1 to 4 was manufactured, and a heteroepitaxial layer 3 was grown on it. The presence or absence of cracking was then compared with the case where the heteroepitaxial layer 3 was grown on a single-crystal silicon substrate that did not satisfy any of conditions 1 to 4. The specific procedure is as follows.

[0051] (Relationship between boron content and slip / cracking (Examples 1 and 2, Comparative Example 1)) Diameter 300mm, surface has (111) faces, boron 2.0 × 10 15 atoms / cm 3 From 1.0 × 10 18 atoms / cm 3 Three types of boron-doped silicon single-crystal substrates (Comparative Example 1, Example 1, Example 2) containing different amounts of boron were manufactured. The oxygen content of all substrates was 2.0 × 10⁻⁶. 17 atoms / cm 3 The carbon content of both substrates is 2.0 × 10⁻⁶. 15 atoms / cm 3Nitrogen was not doped into the substrate. After growing 3 μm thick GaN on this substrate, the average length of the slip within the substrate was determined using X-ray topography. At this time, the presence or absence of cracks was visually checked. The reason for determining the slip length is that while quantitative evaluation of cracks is difficult, generally, the shorter the slip length, the less likely cracks are to occur, so the slip length was used as an indicator of the likelihood of cracking. The relationship between boron content and slip / cracking is shown in Table 1. As shown in Table 1, when the boron content is 2.0 × 10⁻⁶ 15 atoms / cm 3 The substrate had cracks, but the content was 1.0 × 10 16 atoms / cm 3 The above circuit boards showed no cracks, and the slip length was also shortened. Therefore, the boron content was 1.0 × 10 16 atoms / cm 3 It was found that cracking can be suppressed if the above conditions are met.

[0052] [Table 1]

[0053] (Relationship between oxygen content and slip / cracking (Examples 3, 4, and Comparative Example 2)) Diameter 300mm, surface is (111) plane, oxygen 2.0 × 10 17 atoms / cm 3 From 2.0 × 10 18 atoms / cm 3 Three types of boron-doped silicon single crystal substrates (Comparative Example 2, Example 3, Example 4) containing different amounts of boron were obtained. The boron content of all substrates was 2.0 × 10⁻⁶. 15 atoms / cm 3 The carbon content of both substrates is 2.0 × 10⁻⁶. 15 atoms / cm 3and nitrogen was not doped. After growing 3-μm-thick GaN on this substrate, the average value of the length of slips in the substrate was determined using X-ray topography. At this time, the presence or absence of cracks was visually confirmed. The relationship between the oxygen content and slips / cracks is shown in Table 2. As shown in Table 2, cracks occurred in the substrate with an oxygen content of 2.0×10 17 atoms / cm 3 , but cracks did not occur in the substrate with a content of 5.0×10 17 atoms / cm 3 or more, and the slip length was also short. Therefore, it was found that cracks can be suppressed if the oxygen content is 5.0×10 17 atoms / cm 3 or more.

[0054]

Table 2

[0055] (Relationship between nitrogen content and slips / cracks (Example 5, Example 6, Comparative Example 3)) Three types of boron-doped single-crystalline silicon substrates (Comparative Example 3, Example 5, Example 6) with a diameter of 300 mm, a (111) surface, and different amounts of nitrogen content ranging from 1.0×10 14 atoms / cm 3 to 9.0×10 15 atoms / cm 3 were produced. The boron content was 2.0×10 15 atoms / cm 3 , the oxygen content was 2.0×10 17 atoms / cm 3 , and the carbon content was 2.0×10 15 atoms / cm 3 . After growing 3-μm-thick GaN on this substrate, the average value of the length of slips in the substrate was determined using X-ray topography. At this time, the presence or absence of cracks was visually confirmed. The relationship between the nitrogen content and slips / cracks is shown in Table 3. As shown in Table 3, when the nitrogen content was 1.0×10 14 atoms / cm 3The circuit board had cracks, but the content was 5.0 × 10 15 atoms / cm 3 The above substrates showed no cracks, and the slip length was also shortened. Therefore, the nitrogen content was 5.0 × 10 15 atoms / cm 3 It was found that cracking can be suppressed if the above conditions are met.

[0056] [Table 3]

[0057] (Relationship between carbon content and slip / cracking (Examples 7, 8, and 4)) Diameter 300 mm, surface has (111) faces, carbon 2.0 × 10 15 atoms / cm 3 From 5.0 x 10 16 atoms / cm 3 Boron-doped single-crystal silicon substrates (Comparative Example 4, Example 7, Example 8) containing different amounts of boron were manufactured. The boron content was 2.0 × 10⁻⁶. 15 atoms / cm 3 The oxygen content is 2.0 × 10⁻⁶ 17 atoms / cm 3 Nitrogen was not doped into the substrate. After growing 3 μm thick GaN on this substrate, the average length of the slip within the substrate was determined using X-ray topography. At this time, the presence or absence of cracks was visually checked. The relationship between carbon content and slip / cracks is shown in Table 4. As shown in Table 4, when the carbon content is 2.0 × 10⁻⁶ 15 atoms / cm 3 The circuit board had cracks, but the content was 5.0 × 10 15 atoms / cm 3 The above substrates showed no cracks, and the slip length was also shortened. Therefore, the carbon content was 5.0 × 10 15 atoms / cm 3 It was found that cracking can be suppressed if the above conditions are met.

[0058] [Table 4]

[0059] Since cracking and chipping are difficult to evaluate quantitatively, the slip length was used for evaluation. Specifically, Figure 3 shows a graph of the relationship between elemental content and slip length for Examples 1-8 and Comparative Examples 1-4. As shown in Figure 3, after growing heteroepitaxial layers 3 on 300 mm diameter silicon substrates with varying types and contents of light elements, the slip length was evaluated using X-ray topography. The results showed that there were significant differences in the occurrence of slip depending on the type and contents of light elements in the silicon, but that slip tended to be suppressed as the content increased. Furthermore, it was suggested that warping was also suppressed as a result of the suppression of slip. While oxygen and carbon showed the greatest effect on individual elements, it was found that other elements were also effective. In other words, this result shows that not just any substrate will do for heteroepitaxial applications; silicon substrate design must be tailored to the specific properties, including strength.

[0060] (When conditions 1 to 4 are combined (Examples 9 to 12, Comparative Example 5)) A silicon single crystal substrate with a diameter of 300 mm, a (111) plane on its surface, and containing boron, oxygen, nitrogen, and carbon to meet the following requirements was manufactured. Comparative Example 5: Boron, oxygen, nitrogen, and carbon content that does not meet conditions 1-4. Example 9: A mixture containing one of the following elements: boron, oxygen, nitrogen, or carbon, satisfying one of conditions 1-4 (4 possibilities). Example 10: Two of the following elements—boron, oxygen, nitrogen, and carbon—have content that satisfies any of conditions 1-4 (6 combinations). Example 11: Of boron, oxygen, nitrogen, and carbon, three have content levels that satisfy one of conditions 1-4 (4 possibilities). Example 12: A mixture in which the content of four of the following elements—boron, oxygen, nitrogen, and carbon—satisfies any of conditions 1 to 4. After growing 3 μm thick GaN on these substrates, the average length of the slip within the substrate was determined using X-ray topography. The results are shown in Table 5. As shown in Table 5, the average slip length decreased as the number of elements satisfying conditions 1 to 4 increased, indicating that combining conditions 1 to 4 resulted in a greater suppression of warping and cracking.

[0061] [Table 5]

[0062] From these results, it was found that the heteroepitaxial single-crystal silicon substrate 1 that satisfies one or more of conditions 1 to 4 has a shorter slip length and can suppress cracking compared to the single-crystal silicon substrate that does not satisfy any of conditions 1 to 4. Furthermore, it was found that the more of conditions 1 to 4 that were met, the shorter the slip length became, and the greater the effect of suppressing cracking.

[0063] This specification includes the following embodiments: [1]: A heteroepitaxial single-crystal silicon substrate for growing a heteroepitaxial layer on its surface, A single-crystal silicon substrate for heteroepitaxial applications, characterized by satisfying one or more of the following four conditions. Condition 1: Dopant content is 1.0 × 10 16 atoms / cm 3 That's all. Condition 2: Oxygen content is 5.0 × 10 17 atoms / cm 3 That's all. Condition 3: Nitrogen content is 5.0 × 10 15 atoms / cm 3 That's all. Condition 4: Carbon content is 5.0 × 10 15 atoms / cm 3 That's all. [2]: The heteroepitaxial single-crystal silicon substrate according to [1] above, characterized in that the dopant is boron. [3]: A heteroepitaxial single-crystal silicon substrate as described in [1] or [2] above, The heteroepitaxial layer formed on the surface of the heteroepitaxial single-crystal silicon substrate, Epitaxial substrate characterized by comprising [4]: The epitaxial substrate according to [3] above, characterized in that the material constituting the heteroepitaxial layer is one of GaN, AlN, or diamond. [5]: A semiconductor device comprising the epitaxial substrate described in [3] or [4] above. [6]: A single crystal manufacturing process for producing single crystal silicon that satisfies one or more of the following four conditions, Condition 1: Dopant content is 1.0 × 10 16 atoms / cm 3 That's all. Condition 2: Oxygen content is 5.0 × 10 17 atoms / cm 3 That's all. Condition 3: Nitrogen content is 5.0 × 10 15 atoms / cm 3 That's all. Condition 4: Carbon content is 5.0 × 10 15 atoms / cm 3 That's all. A substrate manufacturing process for manufacturing a heteroepitaxial single-crystal silicon substrate from the single-crystal silicon manufactured in the single-crystal manufacturing process, A method for manufacturing a single-crystal silicon substrate for heteroepitaxial applications, characterized by including the following:

[0064] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention. [Explanation of Symbols]

[0065] 1...Single-crystal silicon substrate for heteroepitaxial layers, 3...Heteroepitaxial layer, 5...Epitaxial substrate, 7...Simulator.

Claims

1. A heteroepitaxial single-crystal silicon substrate for growing a heteroepitaxial layer on its surface, A single-crystal silicon substrate for heteroepitaxial applications, characterized by satisfying one or more of the following four conditions. Condition 1: Dopant content is 1.0 × 10 １６ atoms / cm ３ That's all. Condition 2: Oxygen content is 5.0 × 10 １７ atoms / cm ３ That's all. Condition 3: Nitrogen content is 5.0 × 10 １５ atoms / cm ３ That's all. Condition 4: Carbon content is 5.0 × 10 １５ atoms / cm ３ That's all.

2. The heteroepitaxial single-crystal silicon substrate according to claim 1, characterized in that the dopant is boron.

3. A heteroepitaxial single-crystal silicon substrate according to claim 1 or 2, The heteroepitaxial layer formed on the surface of the heteroepitaxial single-crystal silicon substrate, An epitaxial substrate characterized by comprising the following features.

4. The epitaxial substrate according to claim 3, characterized in that the material constituting the heteroepitaxial layer is one of GaN, AlN, or diamond.

5. A semiconductor device comprising the epitaxial substrate described in claim 3.

6. A single crystal manufacturing process for producing single crystal silicon that satisfies one or more of the following four conditions, Condition 1: The content of the dopant is 1.0×10 １６ atoms / cm ３ or more Condition 2: Oxygen content is 5.0 × 10 １７ atoms / cm ３ That's all. Condition 3: Nitrogen content is 5.0 × 10 １５ atoms / cm ３ That's all. Condition 4: Carbon content is 5.0 × 10 １５ atoms / cm ３ That's all. A substrate manufacturing process for manufacturing a heteroepitaxial single-crystal silicon substrate from the single-crystal silicon manufactured in the single-crystal manufacturing process, A method for manufacturing a single-crystal silicon substrate for heteroepitaxial applications, characterized by including the following:

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