Monocrystalline diamond substrate with twin defects removed and method for manufacturing same

Abstract

The present invention relates to a monocrystalline diamond substrate with twin defects removed and a method for manufacturing same and, more particularly, to a monocrystalline diamond substrate with twin defects removed and a method for manufacturing same, which provides a monocrystalline diamond substrate including a monocrystalline diamond layer oriented in the (111) direction by disposing a buffer layer including an Ir metal layer on the upper surface of a base layer including an R-plane sapphire substrate to thus control defects in the substrate, and a method for manufacturing same.

Description

Single crystal diamond substrate with removed twin defects and method for manufacturing the same

[0001] The present invention relates to a single crystal diamond substrate from which twin defects have been removed and a method for manufacturing the same, and more particularly, to a single crystal diamond substrate from which twin defects have been removed and a method for manufacturing the same, which comprises a single crystal diamond substrate including a single crystal diamond layer oriented in the (111) direction and a method for manufacturing the same, by disposing a buffer layer including an Ir metal layer on the upper surface of a base layer including an R-plane sapphire substrate, thereby controlling defects in the substrate.

[0002]

[0003] Recently, a technology has been developed for manufacturing semiconductor devices using single-crystal diamond as a substrate material. Single-crystal diamond substrates are a promising substrate material for manufacturing ultra-wide bandgap (UWBG) semiconductor devices. Semiconductor devices using single-crystal diamond substrates offer improved energy efficiency and can be miniaturized and lightweight, enabling the production of next-generation power devices for electric vehicles, ultra-high-frequency communications, and quantum sensors. Consequently, there is a growing demand for technologies capable of manufacturing high-quality single-crystal diamond substrates.

[0004] A diamond semiconductor device substrate oriented in the (111) direction has superior doping efficiency and quantum properties than a substrate oriented in the (001) direction, making it suitable for manufacturing high-performance electronic devices and quantum sensors. However, the substrate has a problem in that defects are likely to occur in the substrate during formation.

[0005] That is, there is a need for a technology for forming a single crystal diamond substrate that can be used as a substrate for next-generation semiconductor devices by having UWBG and is oriented in the (111) direction, while controlling defects in the substrate, and a method for manufacturing the same.

[0006] The present invention provides a single crystal diamond substrate including a single crystal diamond layer oriented in the (111) direction and a method for manufacturing the same, in which defects of the substrate are controlled by arranging a buffer layer including an Ir metal layer on the upper surface of a base layer including an R-plane sapphire substrate, and a method for manufacturing the same, and a single crystal diamond substrate from which twin defects are removed and a method for manufacturing the same.

[0007]

[0008] In order to solve the above problem, one embodiment of the present invention provides a single crystal diamond substrate having controlled defects of the substrate, comprising: a base layer; a buffer layer formed on the base layer; and a single crystal diamond layer formed on the buffer layer; wherein the base layer includes a sapphire substrate, the sapphire substrate has an R-plane oriented in a predetermined direction, and the buffer layer includes an Ir metal layer.

[0009] In some embodiments of the present invention, the single crystal diamond substrate may have three peaks spaced 120 degrees apart on an X-ray diffraction pole figure.

[0010] In some embodiments of the present invention, the single crystal diamond substrate can control twin defects that occur during formation of the single crystal diamond layer.

[0011] In some embodiments of the present invention, the single crystal diamond substrate further includes a pre-diamond layer formed on the buffer layer, wherein the single crystal diamond layer is formed on the pre-diamond layer, and the pre-diamond layer may have a thin thickness compared to the thickness of the single crystal diamond layer.

[0012] In some embodiments of the present invention, the single crystal diamond substrate may have a form in which the single crystal diamond layer is separated from the base layer after the base layer, buffer layer, and single crystal diamond layer are formed sequentially.

[0013] In some embodiments of the present invention, the buffer layer may include an Ir metal layer oriented in the (111) direction.

[0014] In some embodiments of the present invention, the buffer layer may have a thickness of 20 nm to 1 μm.

[0015] In some embodiments of the present invention, the single crystal diamond layer is grown while being oriented in a plane direction corresponding to the plane direction of the buffer layer, and the single crystal diamond substrate can control defects of the substrate by the buffer layer and the single crystal diamond layer being oriented in a plane direction corresponding to each other.

[0016] In some embodiments of the present invention, the single crystal diamond layer may include a single crystal diamond layer oriented in the (111) direction.

[0017]

[0018] In order to solve the above problem, one embodiment of the present invention provides a method for manufacturing a single crystal diamond substrate with controlled defects of a substrate, comprising: a substrate layer preparation step of preparing a substrate layer; a buffer layer formation step of forming a buffer layer on the substrate layer; and a single crystal diamond layer formation step of forming a single crystal diamond layer on the buffer layer; wherein the substrate layer includes a sapphire substrate, the sapphire substrate has an R-plane oriented in a preset direction, and the buffer layer includes an Ir metal layer.

[0019] In some embodiments of the present invention, the single crystal diamond substrate may have three peaks spaced 120 degrees apart on an X-ray diffraction pole figure.

[0020] In some embodiments of the present invention, the single crystal diamond substrate can control twin defects that occur during formation of the single crystal diamond layer.

[0021]

[0022] In order to solve the above problems, one embodiment of the present invention provides a method for manufacturing a single crystal diamond substrate with controlled defects of a substrate, comprising: a substrate layer preparation step of preparing a substrate layer; a buffer layer formation step of forming a buffer layer on the substrate layer; a pre-diamond layer formation step of forming a pre-diamond layer on the buffer layer; and a single crystal diamond layer formation step of forming a single crystal diamond layer on the pre-diamond layer; wherein the substrate layer includes a sapphire substrate, the sapphire substrate has an R-plane oriented in a preset direction, and the buffer layer includes an Ir metal layer.

[0023] In some embodiments of the present invention, the single crystal diamond substrate may have three peaks spaced 120 degrees apart on an X-ray diffraction pole figure.

[0024] In some embodiments of the present invention, the single crystal diamond substrate can control twin defects that occur during formation of the single crystal diamond layer.

[0025]

[0026] According to one embodiment of the present invention, by arranging a buffer layer including an Ir metal layer on the upper surface of an R-plane sapphire substrate and forming a single-crystal diamond layer on the upper surface of the buffer layer, defects of a single-crystal diamond substrate oriented in the (111) direction can be controlled, thereby exerting an effect of improving quality.

[0027] According to one embodiment of the present invention, by forming an Ir metal layer on the upper surface of an R-plane sapphire substrate, the effect of controlling defects in the Ir metal layer can be exerted.

[0028] According to one embodiment of the present invention, the effect of controlling defects in a single crystal diamond layer can be achieved by growing a single crystal diamond layer on the upper surface of a buffer layer in which defects of a substrate are controlled.

[0029] According to one embodiment of the present invention, since the upper surfaces of each of the buffer layer and the single crystal diamond layer are oriented in the (111) direction and the shapes of the atoms arranged on the upper surfaces correspond to each other, the residual stress of the single crystal diamond layer due to the difference in lattice constant and thermal expansion coefficient between the single crystal diamond layer and the substrate layer can be minimized, thereby exhibiting an effect of improving the durability of the single crystal diamond substrate.

[0030] According to one embodiment of the present invention, by forming a preliminary diamond layer that serves as a seed for the diamond layer on the upper surface of the buffer layer, the yield of the single crystal diamond layer can be increased.

[0031] According to one embodiment of the present invention, a single crystal diamond substrate can exhibit an effect in which the single crystal diamond layer can be easily provided by separating the single crystal diamond layer from the base layer.

[0032]

[0033] FIG. 1 is a schematic diagram of a single crystal diamond substrate according to one embodiment of the present invention.

[0034] FIG. 2 illustrates details of a lattice structure of a sapphire substrate according to one embodiment of the present invention.

[0035] FIG. 3 illustrates details of the lattice structure of iridium (Ir) and diamond according to one embodiment of the present invention.

[0036] FIG. 4 illustrates details of X-ray diffraction patterns of a substrate layer and a buffer layer according to one embodiment of the present invention.

[0037] FIG. 5 illustrates details of an X-ray diffraction pole figure according to one embodiment of the present invention.

[0038] Figure 6 schematically illustrates the known twin defect.

[0039] Figure 7 schematically illustrates a method for manufacturing a single crystal diamond substrate according to one embodiment of the present invention.

[0040] FIG. 8 schematically illustrates an example of performing each step of a method for manufacturing a single crystal diamond substrate according to one embodiment of the present invention.

[0041] Figure 9 schematically illustrates a method for manufacturing a single crystal diamond substrate according to another embodiment of the present invention.

[0042] FIG. 10 schematically illustrates an example of performing each step of a method for manufacturing a single crystal diamond substrate according to another embodiment of the present invention.

[0043]

[0044] Hereinafter, various embodiments and / or aspects are now disclosed with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of one or more aspects. However, it will be apparent to one skilled in the art that such aspects may be practiced without these specific details. The following description and the attached drawings detail specific exemplary aspects of one or more aspects. However, these aspects are exemplary, and it is to be understood that any of the various methods within the principles of the various aspects may be utilized, and the description is intended to encompass all such aspects and their equivalents.

[0045] Additionally, various aspects and features will be presented by systems that may include a number of devices, components, and / or modules. It is also to be understood and appreciated that various systems may include additional devices, components, and / or modules, and / or may not include all of the devices, components, and modules discussed in connection with the drawings.

[0046] The terms “embodiment,” “example,” “aspect,” and “example” used herein may not be construed to imply that any aspect or design described is better or advantageous over other aspects or designs.

[0047] Additionally, it should be understood that the terms “comprises” and / or “comprising” imply the presence of the features and / or components, but do not exclude the presence or addition of one or more other features, components and / or groups thereof.

[0048] Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. The term and / or includes a combination of a plurality of related described items or any of a plurality of related described items.

[0049] Additionally, in the embodiments of the present invention, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an ideal or overly formal sense unless explicitly defined in the embodiments of the present invention.

[0050]

[0051] A single crystal diamond substrate (1) is attracting attention as a material for next-generation semiconductor devices. In particular, a single crystal diamond substrate (1) oriented in the (111) direction has high thermal conductivity and low defect density, making it essential for manufacturing high-power and high-performance electronic devices. Preferably, in order to manufacture a single crystal diamond substrate (1) having a large diameter, the single crystal diamond substrate (1) is preferably formed by a heterogeneous growth method.

[0052] However, the single crystal diamond substrate (1) oriented in the above (111) direction has a small lattice constant, so it is not easy to find an appropriate substrate layer (100), and in particular, the single crystal diamond substrate (1) oriented in the above (111) direction formed by the heterogeneous growth method has a problem in that defects are likely to occur.

[0053]

[0054] To solve this problem, the present invention attempted to heterogeneously grow a single-crystal diamond layer (300) using an Ir (iridium) metal layer oriented in the (111) direction on the upper surface of an R-plane sapphire substrate.

[0055] More specifically, in the present invention, a single crystal diamond substrate (1) can be formed by forming an Ir metal layer on the upper surface of a sapphire substrate having an R-plane (1-102) surface and heterogeneously growing a single crystal diamond layer (300) on the upper surface.

[0056] At this time, it is preferable that the Ir metal layer is oriented in the (111) direction, and thus the single crystal diamond layer (300) can be oriented in the (111) direction. The (111) direction corresponds to the direction of the crystal plane indicated by the Miller index of the crystal plane, and at this time, the Miller index of the crystal plane corresponds to the reciprocal of the value obtained by dividing the length of the three-dimensional coordinate axis by the unit length of the axis, expressed as the smallest integer ratio.

[0057] Accordingly, the single crystal diamond layer (300) may have no or very few twin defects, which are a type of defect in the substrate, due to controlled defects.

[0058]

[0059] That is, the present invention can provide a single crystal diamond substrate (1) having a high quality and being oriented in the (111) direction and having defects in the substrate controlled by forming a buffer layer (200) including an Ir metal layer on the upper surface of a base layer (100) including an R-plane sapphire substrate and forming a single crystal diamond layer (300) on the upper surface of the buffer layer (200).

[0060]

[0061] Hereinafter, a single crystal diamond substrate (1) according to one embodiment of the present invention will be described in detail.

[0062]

[0063] FIG. 1 is a schematic diagram of a single crystal diamond substrate (1) according to one embodiment of the present invention, FIG. 2 is a diagram showing details of a lattice structure of a sapphire substrate according to one embodiment of the present invention, and FIG. 3 is a diagram showing details of a lattice structure of iridium (Ir) and diamond according to one embodiment of the present invention.

[0064]

[0065] As illustrated in FIG. 1, a single crystal diamond substrate (1) having controlled defects according to one embodiment of the present invention may include a base layer (100); a buffer layer (200) formed on the base layer (100); and a single crystal diamond layer (1) formed on the buffer layer (200). In this case, the base layer (100) may include a sapphire substrate, the sapphire substrate may have an R-plane oriented in a preset direction, and the buffer layer (200) may include an Ir metal layer.

[0066]

[0067] The above-mentioned base layer (100) is a composition of a base substrate for growing a single crystal diamond layer (300), and corresponds to a composition made of different components from the single crystal diamond layer (300). In the present invention, a heterogeneous growth method utilizing a heterogeneous substrate suitable for manufacturing a large diameter of 2 inches or more, which can be used as a substrate for a semiconductor device, with high purity was used.

[0068]

[0069] The existing heterogeneous growth method had the problem of generating numerous substrate defects when forming a single crystal diamond layer oriented in the (111) direction.

[0070] To solve this problem, the present invention proposes an R-plane sapphire substrate as a base layer (100). In one embodiment of the present invention, the R-plane sapphire substrate corresponds to a sapphire substrate oriented so that the upper surface has a (1-102) direction. As illustrated in Fig. 2, the sapphire substrate has an hcp (hexagonal close-packed) structure. Due to this structure, the sapphire substrate is stable against temperature without phase change from extremely low temperatures to ultra-high temperatures, and has excellent mechanical properties, making it suitable as a substrate for heterogeneous growth.

[0071] More specifically, as illustrated in FIG. 2(a), the R-plane sapphire substrate corresponds to a sapphire substrate having a crystal plane as an upper surface that is inclined at an angle of 35.5 degrees with respect to the c-axis of the sapphire crystal structure. In particular, the R-plane sapphire substrate has higher mechanical strength and thermal stability than sapphire substrates oriented in other plane directions, which may mean that the R-plane sapphire substrate is more suitable for high temperature and high stress fields such as heterogeneous growth. According to one embodiment of the present invention, when a buffer layer (200) is disposed on the R-plane sapphire substrate as a base layer (100), it can be confirmed that defects within the plane of the buffer layer (200) are controlled.

[0072] Meanwhile, according to one embodiment of the present invention, by forming an Ir metal layer on the upper surface of an R-plane sapphire substrate, the effect of controlling defects in the Ir metal layer can be exerted. The effect can be confirmed through experimental results such as X-ray diffraction analysis and X-ray rotation pole figure, and the experimental results will be shown in the drawings described below.

[0073]

[0074] Meanwhile, the sapphire substrate may have various planes in addition to the R-plane described above, and may have, for example, a C-plane as illustrated in FIG. 2(b). The C-plane sapphire substrate refers to a sapphire substrate having a crystal plane as an upper surface that is inclined at a vertical angle with respect to the c-axis of the sapphire crystal structure. According to one embodiment of the present invention, when a buffer layer (200) is disposed on a C-plane sapphire substrate as a base layer (100), defects within the plane of the buffer layer (200) are not controlled.

[0075]

[0076] The above buffer layer (200) may include an Ir metal layer oriented in the (111) direction. In addition, the buffer layer (200) may have a thickness of 20 nm to 1 μm.

[0077] Preferably, the buffer layer (200) may be arranged to have a thickness of 100 nm to 700 nm. More preferably, the buffer layer (200) may be arranged to have a thickness of 500 nm.

[0078] In one embodiment of the present invention, the buffer layer (200) may be formed on the upper surface of the substrate layer using any one of a sputtering method, an E-beam evaporation method, and a CVD (chemical vapor deposition) device.

[0079]

[0080] The above buffer layer (200) corresponds to a configuration for suppressing the occurrence of defects caused by differences in lattice constants and thermal expansion coefficients between the base layer (100), which is a heterogeneous substrate, and the single crystal diamond layer (300) in one embodiment of the present invention.

[0081] At this time, it is preferable that the upper surface of the buffer layer is oriented in the (111) direction, and the shape of the atoms arranged on the upper surface of the buffer layer (200) corresponds to or is similar to the shape of the atoms arranged on the upper surface of the single crystal diamond layer (300) formed on the upper side.

[0082] More specifically, the buffer layer (200) includes an Ir metal layer having an fcc (face-centered cubic) structure as illustrated in FIG. 3(a), and the fcc structure has a triangular shape in the shape of atoms arranged on a crystal plane in the (111) direction. As described above, since the upper surface of the buffer layer (200) is oriented in the (111) direction, it is preferable that the atoms arranged on the upper surface of the buffer layer (200) have a triangular shape.

[0083] Meanwhile, the single crystal diamond layer (300) includes a single crystal diamond layer having a diamond cubic structure as shown in FIG. 3(b), and the diamond cubic structure has a triangular shape in the shape of atoms arranged on the crystal plane in the (111) direction.

[0084] In this way, since the upper surfaces of each of the buffer layer (200) and the single crystal diamond layer (300) are oriented in the (111) direction and the shapes of the atoms arranged on the upper surfaces correspond to each other, the residual stress of the single crystal diamond layer (300) due to the difference in lattice constant and thermal expansion coefficient between the single crystal diamond layer (300) and the substrate layer (100) can be minimized, thereby exerting an effect of improving the durability of the single crystal diamond substrate (1).

[0085]

[0086] The above single crystal diamond layer (300) can be formed on the upper surface of the buffer layer (200) and corresponds to a configuration that can be used as a substrate for semiconductor devices and electronic devices.

[0087]

[0088] In general, a single crystal diamond layer (300) can be manufactured by various manufacturing methods such as a high temperature and high pressure method, a homogeneous growth method, and a heterogeneous growth method. The present invention relates to a heterogeneously grown single crystal diamond layer (300), and the single crystal diamond layer (300) according to an embodiment of the present invention can be formed using any one of ALD (atomic layer deposition), CVD, or PVD (physical vapor deposition) equipment, and as the CVD equipment, HF-CVD (hot filament-CVD), MP-CVD (micro plasma-CVD), or RF-CVD (RF plasma-CVD) equipment can be used.

[0089]

[0090] According to one embodiment of the present invention, a single crystal diamond layer (300) is grown while being oriented in a plane direction corresponding to the plane direction of the buffer layer (200), and the single crystal diamond substrate (1) can control defects by the buffer layer (200) and the single crystal diamond layer (300) oriented in a plane direction corresponding to each other.

[0091] Accordingly, the single crystal diamond layer (300) may include a single crystal diamond layer (300) oriented in the (111) direction. At this time, defects in the single crystal diamond layer (300) may be controlled as a buffer layer (200) is formed on the upper surface of the base layer (100).

[0092] That is, according to one embodiment of the present invention, by growing a single crystal diamond layer (300) on the upper surface of a buffer layer (200) whose defects are controlled, an effect of controlling defects in the single crystal diamond layer (300) can be exerted, and by arranging a buffer layer (200) including an Ir metal layer oriented in the (111) direction, an effect of improving the quality of the single crystal diamond layer (300) oriented in the (111) direction can be exerted.

[0093]

[0094] FIG. 4 illustrates details of the X-ray diffraction pattern of the substrate layer (100) and the buffer layer (200) according to one embodiment of the present invention.

[0095]

[0096] The above substrate layer (100) is oriented in the (1-102) direction as an R-plane sapphire substrate, and the buffer layer (200) is oriented in the (111) direction.

[0097] In one embodiment of the present invention, the substrate layer (100) and the buffer layer (200) exhibit X-ray diffraction patterns as illustrated in FIG. 4. According to the pattern, it can be confirmed that the substrate layer has an R-plane sapphire substrate oriented in the (1-102) direction, and the buffer layer (200) also has an Ir metal layer oriented in the (111) direction. At this time, the Sapphire (012) peak of FIG. 4 corresponds to the aforementioned (1-102) direction.

[0098] In this way, the above-mentioned substrate layer (100) and buffer layer (200) correspond to layers made of single crystals.

[0099]

[0100] FIG. 5 illustrates details of an X-ray diffraction pole figure according to one embodiment of the present invention, and FIG. 6 schematically illustrates details of a known twin defect.

[0101]

[0102] A single crystal diamond substrate (1) according to one embodiment of the present invention may have three peaks spaced at 120 degree intervals on an X-ray diffraction pole figure.

[0103] The above X-ray diffraction pole figure is an analysis method that shows the direction distribution of lattice planes within a plane, and the base layer (100) and the buffer layer (200) may have three peaks at intervals of 120 degrees on the X-ray diffraction pole figure as illustrated in FIG. 5. This means that no twinning defects have occurred within the planes of each of the base layer (100) and the buffer layer (200). That is, the single crystal diamond layer (300) according to one embodiment of the present invention means that twinning defects can be controlled.

[0104] More specifically, a twinning defect is a type of defect that commonly occurs when growing a single crystal diamond layer (300) oriented in the (111) direction, and occurs when the crystal lattices are oriented in different plane directions within a corresponding plane. As described above, the buffer layer (200) and the single crystal diamond layer (300) are oriented in the (111) direction, so the atoms arranged on the upper surface have a triangular shape. At this time, each of the buffer layer (200) and the single crystal diamond layer (300) can exhibit an X-ray diffraction pole figure as in Fig. 6(a), and as in Fig. 6(a), each of the buffer layer (200) and the single crystal diamond layer (300) has an α corresponding to the angle between the peaks and the central axis of 120 degrees, which means that no twin defects have occurred in the plane of the buffer layer (200) and the single crystal diamond layer (300).

[0105] On the other hand, if β, which corresponds to the angle between the peaks and the central axis, shows an angle of 60 degrees as in FIG. 6(b), it may mean that a twin defect has occurred in the plane of the buffer layer (200) and the single crystal diamond layer (300). For example, if any one plane in the plane of the Ir metal layer included in the buffer layer (200) rotates 60 degrees clockwise with respect to the central axis, the peak of the X-ray diffraction pole figure may have a shape as in FIG. 6(b). At this time, β may have an angle of 60 degrees, and may have six peaks spaced apart from each other at intervals of 60 degrees on the X-ray diffraction pole figure. Meanwhile, the difference in the X-ray diffraction pole figure as described above may be caused by the relatively high energy required when a defect is generated in the single crystal diamond layer (300) formed on the R-plane sapphire substrate.

[0106] That is, according to one embodiment of the present invention, the effect of controlling defects in the single crystal diamond layer (300) can be achieved by growing the single crystal diamond layer (300) on the upper surface of the buffer layer (200) whose defects in the substrate are controlled.

[0107]

[0108] Hereinafter, a method for manufacturing a single crystal diamond substrate (1) according to one embodiment of the present invention will be described in detail.

[0109]

[0110] FIG. 7 schematically illustrates a method for manufacturing a single crystal diamond substrate (1) according to one embodiment of the present invention, and FIG. 8 schematically illustrates an example of performing each step of the method for manufacturing a single crystal diamond substrate (1) according to one embodiment of the present invention.

[0111]

[0112] Meanwhile, a single crystal diamond substrate (1) according to one embodiment of the present invention can be formed by the following manufacturing method.

[0113] Preferably, it includes a substrate layer preparation step (S100) of preparing a substrate layer (100); a buffer layer formation step (S200) of forming a buffer layer (200) on the substrate layer (100); and a single crystal diamond layer formation step (S400) of forming a single crystal diamond layer (300) on the buffer layer (200); wherein the substrate layer (100) includes a sapphire substrate, the sapphire substrate has an R-plane oriented in a preset direction, and the buffer layer (200) may include an Ir metal layer.

[0114] In this configuration, the single crystal diamond substrate (1) can have three peaks spaced at 120 degree intervals on the X-ray diffraction pole figure, and can control twin defects that occur when forming the single crystal diamond layer (300).

[0115]

[0116] More specifically, in order to form the single crystal diamond substrate (1) in one embodiment of the present invention, a buffer layer (200) may be formed on the upper surface of the substrate layer (100) as shown in FIGS. 8(a) and 8(b). Thereafter, a single crystal diamond layer (300) may be formed on the upper surface of the buffer layer (200) as shown in FIG. 8(c).

[0117] In this configuration, the buffer layer (200) can be oriented in the (111) direction while controlling defects in the substrate, and the single crystal diamond layer (300) can exert the effect of controlling defects in the substrate as it is grown on the upper surface of the buffer layer (200) where defects in the substrate are controlled. In addition, by forming the single crystal diamond layer (300) on the upper surface of the buffer layer (200), the residual stress due to the difference in lattice constant and thermal expansion coefficient between the single crystal diamond layer (300) and the base layer (100) can be minimized, thereby exerting the effect of improving the durability of the single crystal diamond substrate (1).

[0118]

[0119] Meanwhile, a single crystal diamond substrate (1) manufactured by such a manufacturing method may have a form in which the base layer (100), buffer layer (200), and single crystal diamond layer (300) are formed continuously, and then the single crystal diamond layer (300) is separated from the base layer (100).

[0120] At this time, the single crystal diamond substrate (1) can be separated from any one surface between the upper surface of the base layer (100) and the lower surface of the single crystal diamond layer (300).

[0121] That is, the single crystal diamond substrate (1) according to one embodiment of the present invention can exhibit the effect of allowing the single crystal diamond layer (300) to be easily provided by separating the single crystal diamond layer (300) from the base layer (100).

[0122]

[0123] FIG. 9 schematically illustrates a method for manufacturing a single crystal diamond substrate (1) according to another embodiment of the present invention, and FIG. 10 schematically illustrates an example of performing each step of a method for manufacturing a single crystal diamond substrate (1) according to another embodiment of the present invention.

[0124]

[0125] Meanwhile, the present invention may further include a pre-diamond layer (400) that assists in the process of forming a single crystal diamond layer (300). A single crystal diamond substrate (1) further including a pre-diamond layer (400) may be formed by the following manufacturing method.

[0126]

[0127] Preferably, it comprises a substrate layer preparation step (S100) of preparing a substrate layer (100); a buffer layer formation step (S200) of forming a buffer layer (200) on the substrate layer (100); a preliminary diamond layer formation step (S400) of forming a preliminary diamond layer (400) on the buffer layer; and a single crystal diamond layer formation step (S300) of forming a single crystal diamond layer (300) on the preliminary diamond layer (400); wherein the substrate layer (100) includes a sapphire substrate, the sapphire substrate has an R-plane oriented in a preset direction, and the buffer layer (200) may include an Ir metal layer.

[0128] In this configuration, the single crystal diamond substrate (1) can have three peaks spaced at 120 degree intervals on the X-ray diffraction pole figure, and can control twin defects that occur when forming the single crystal diamond layer (300).

[0129] In addition, in this configuration, the single crystal diamond substrate (1) further includes a pre-diamond layer (400) formed on the buffer layer (200), and the single crystal diamond layer (300) is formed on the pre-diamond layer (400), and the pre-diamond layer (400) may have a thin thickness compared to the thickness of the single crystal diamond layer (300).

[0130]

[0131] More specifically, in order to form a single crystal diamond substrate (1), a buffer layer (200) can be formed on the upper surface of the base layer (100) as shown in FIG. 9(a) and FIG. 9(b). Thereafter, as shown in FIG. 9(c), a preliminary diamond layer (400) can be formed on the upper surface of the buffer layer (200), and the preliminary diamond layer (400) can serve as a seed for the single crystal diamond layer (300), thereby exerting an effect of easily forming the single crystal diamond layer (300).

[0132] That is, according to one embodiment of the present invention, by forming a preliminary diamond layer (300) that serves as a seed for the diamond layer on the upper surface of the buffer layer (200), the yield of the single crystal diamond layer (300) can be increased.

[0133]

[0134] According to one embodiment of the present invention, by arranging a buffer layer including an Ir metal layer on the upper surface of an R-plane sapphire substrate and forming a single-crystal diamond layer on the upper surface of the buffer layer, defects of a single-crystal diamond substrate oriented in the (111) direction can be controlled, thereby exerting an effect of improving quality.

[0135] According to one embodiment of the present invention, by forming an Ir metal layer on the upper surface of an R-plane sapphire substrate, the effect of controlling defects in the Ir metal layer can be exerted.

[0136] According to one embodiment of the present invention, the effect of controlling defects in a single crystal diamond layer can be achieved by growing a single crystal diamond layer on the upper surface of a buffer layer in which defects of a substrate are controlled.

[0137] According to one embodiment of the present invention, since the upper surfaces of each of the buffer layer and the single crystal diamond layer are oriented in the (111) direction and the shapes of the atoms arranged on the upper surfaces correspond to each other, the residual stress of the single crystal diamond layer due to the difference in lattice constant and thermal expansion coefficient between the single crystal diamond layer and the substrate layer can be minimized, thereby exhibiting an effect of improving the durability of the single crystal diamond substrate.

[0138] According to one embodiment of the present invention, by forming a preliminary diamond layer (300) that serves as a seed of a diamond layer on the upper surface of a buffer layer (200), the yield of a single crystal diamond layer (300) can be increased.

[0139] A single crystal diamond substrate according to one embodiment of the present invention can exhibit the effect of allowing the single crystal diamond layer to be easily provided by separating the single crystal diamond layer from the base layer.

[0140]

[0141] Although the embodiments have been described with limited examples and drawings, those skilled in the art will appreciate that various modifications and variations can be made based on the above teachings. For example, appropriate results can be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents. Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the claims described below.

Claims

1. A single crystal diamond substrate with controlled substrate defects. substrate layer; A buffer layer formed on the above substrate layer; and A single crystal diamond layer formed on the buffer layer; The above substrate layer includes a sapphire substrate, The above sapphire substrate has an R-plane oriented in a predetermined direction, A single crystal diamond substrate, wherein the buffer layer comprises an Ir metal layer.

2. In claim 1, The above buffer layer is, A single crystal diamond substrate having three peaks spaced 120 degrees apart on an X-ray diffraction pole figure.

3. In claim 1, The above single crystal diamond substrate is a single crystal diamond substrate that controls twin defects that occur during the formation of the single crystal diamond layer.

4. In claim 1, The above single crystal diamond substrate, Further comprising a pre-diamond layer formed on the buffer layer; The above single crystal diamond layer is formed on the above pre-diamond layer, A single crystal diamond substrate, wherein the above-mentioned pre-diamond layer has a thin thickness compared to the thickness of the above-mentioned single crystal diamond layer.

5. In claim 1, The above single crystal diamond substrate, A single crystal diamond substrate having a form in which the single crystal diamond layer is separated from the substrate layer after the substrate layer, buffer layer, and single crystal diamond layer are formed continuously.

6. In claim 1, A single crystal diamond substrate, wherein the buffer layer comprises an Ir metal layer oriented in the (111) direction.

7. In claim 1, The above buffer layer is a single crystal diamond substrate with controlled twin defects having a thickness of 20 nm to 1 μm.

8. In claim 1, The above single crystal diamond layer is grown while being oriented in a plane direction corresponding to the plane direction of the buffer layer, A single crystal diamond substrate, wherein defects of the substrate are controlled by the buffer layer and the single crystal diamond layer oriented in corresponding plane directions.

9. In claim 6, A single crystal diamond substrate, wherein the single crystal diamond layer comprises a single crystal diamond layer oriented in the (111) direction.

10. A method for manufacturing a single crystal diamond substrate with controlled substrate defects, Substrate preparation stage for preparing the substrate layer; A buffer layer forming step of forming a buffer layer on the above substrate layer; and A single crystal diamond layer forming step for forming a single crystal diamond layer on the buffer layer; The above substrate layer includes a sapphire substrate, The above sapphire substrate has an R-plane oriented in a predetermined direction, A method for manufacturing a single crystal diamond substrate, wherein the buffer layer includes an Ir metal layer.

11. In claim 10, The above buffer layer is, A method for manufacturing a single crystal diamond substrate having three peaks spaced 120 degrees apart on an X-ray diffraction pole figure.

12. In claim 10, The above single crystal diamond substrate is a method for manufacturing a single crystal diamond substrate, which controls twin defects that occur during the formation of the single crystal diamond layer.

13. A method for manufacturing a single crystal diamond substrate with controlled substrate defects, Substrate preparation stage for preparing the substrate layer; A buffer layer forming step of forming a buffer layer on the above substrate layer; A preliminary diamond layer forming step of forming a preliminary diamond layer on the buffer layer; and A single crystal diamond layer forming step of forming a single crystal diamond layer on the above-mentioned preliminary diamond layer; The above substrate layer includes a sapphire substrate, The above sapphire substrate has an R-plane oriented in a predetermined direction, A method for manufacturing a single crystal diamond substrate, wherein the buffer layer includes an Ir metal layer.

14. In claim 13, The above buffer layer is, A method for manufacturing a single crystal diamond substrate having three peaks spaced 120 degrees apart on an X-ray diffraction pole figure.

15. In claim 13, The above single crystal diamond substrate is a method for manufacturing a single crystal diamond substrate, which controls twin defects that occur during the formation of the single crystal diamond layer.

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