Nitride material, and diode and transistor using same

Abstract

[Problem] The purpose of the present invention is to provide: a nitride material obtained by doping AlN with impurities, in particular, a nitride material having an electrical resistivity of at most 1.0 Ω∙cm; and a diode and a transistor using the same. [Solution] This nitride material is represented by the chemical formula A1α1B1β1Al1-α1-β1N or the chemical formula A1α1B1β1Ga1-α1-β1N, where α1 and β1 satisfy expression (1), or is represented by the chemical formula B2β2Al1-β2N or the chemical formula B2β2Ga1-β2N, where β2 satisfies expression (2), wherein B1 and B2 include a monovalent substance. Expression (1): 0<α1 / β1<6 Expression (2): 0<β2<0.52 (0<α1<1, 0<β1<1, A1 is at least one among Mg and Zn, and B1 and B2 are each at least one among Au, Ag, and Cu.)

Description

Nitride material and diode and transistor using same

[0001] The present invention relates to a nitride material, particularly to a nitride material having electrical conductivity, and to a diode and a transistor using the same.

[0002] Nitride semiconductor materials, such as AlN, GaN, InN, BN, and their alloys, are characterized by their large band gaps. Such large band gap semiconductor materials are considered to be excellent for high-temperature and high-voltage operation and suitable for use in high-power, high-frequency applications and high-temperature environments. In particular, AlN has a particularly large band gap and is considered a promising material.

[0003] As such a semiconductor material, a plurality of Al layers with different Ga concentrations are used. ｘ Ga １－ｘ N layers, and each Al layer is arranged so that the lattice constant in the c-axis direction increases in the +c-axis direction. ｘ Ga １－ｘ A structure in which the concentration x of Al in the N layer is reduced has been proposed (see Patent Document 1).

[0004] Similarly, as such semiconductor materials, those with spatially varying chemical compositions (mixing several to 30% of GaN with AlN) have been proposed (see Non-Patent Document 1).

[0005] Furthermore, it has been reported that the control of p-type electrical conductivity in Mg-doped Al is considered hopeless (see Non-Patent Document 2).

[0006] Japanese Patent Application Laid-Open No. 2023-111945

[0007] Jun Suda and others, Achieving ideal characteristics with aluminum nitride (AlN)-based ultra-wide bandgap semiconductor pn junctions, [online], December 14, 2023, PRTIMES, [Retrieved February 18, 2024], Internet <https: / / prtimes.jp / main / html / rd / p / 000000109.000079452.html> Proceedings of the 84th Autumn Meeting of the Japan Society of Applied Physics, 22p-B101-15, "On the binding energy of Mg acceptors in AlN: Experiments", Kyoto University

[0008] However, the semiconductor material disclosed in Patent Document 1 has the problem that it is made to facilitate the injection of electrons into AlN and is not a p-type semiconductor material.

[0009] Furthermore, the semiconductor material disclosed in Non-Patent Document 1 can be made into a p-type semiconductor material by doping with impurities, but there is a problem in that the thermal energy is insufficient at room temperature, so that electrons are not donated to the acceptor, and the p-type semiconductor material does not exhibit sufficient electrical conductivity.

[0010] In view of the above circumstances, an object of the present invention is to provide a nitride material in which AlN (aluminum nitride) or GaN (gallium nitride) is doped with impurities, in particular a nitride material having low electrical resistivity (conductivity) and semiconductor properties, as well as a diode and a transistor using the same.

[0011] In addition, WO 2020 / 170610 describes Mg α１ Au β１ Al １－α１－β１ Although N is disclosed, it is described as exhibiting insulating properties. Furthermore, the nitride material described in this publication was obtained by numerical calculation, and there was a problem as to whether the valence (number) of Au used in the calculation was correct. As will be described in detail later, the nitride material (A1 α１ B1 β１ Al １－α１－β１ N, A1 α１ B1 β１ Ga １－α１－β１ N, B2 β２ Al １－β２N or B2 β２ Ga １－β２ B1 or B2 contained in N) includes at least one valence, and as described above, the nitride material according to the present invention is conductive (for example, the electrical resistivity is 10 ７ Therefore, the present invention is completely different from the invention described in WO 2020 / 170610.

[0012] The inventors of the present invention have continued to conduct extensive research into the above-mentioned problems and have discovered the following revolutionary nitride material.

[0013] The first aspect of the present invention for solving the above problem is a compound represented by the formula A1 α１ B1 β１ Al １－α１－β１ N or chemical formula A1 α１ B1 β１ Ga １－α１－β１ N, and α1 and β1 satisfy the following formula (1), or the chemical formula B2 β２ Al １－β２ N or chemical formula B2 β２ Ga １－β２ N, β2 satisfies the following formula (2), and B1 and B2 include monovalent ones: 0<α1+β1<1 (1) 0<β2<1 (2) (0<α1<1, 0<β1<1, A1 is at least one of Mg and Zn, and B1 and B2 are at least one of Au, Ag, and Cu.)

[0014] Here, "monovalent" refers to an atomic valence of 1. The valence of B1 can be detected by, for example, X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES), TEM-EELS, etc.

[0015] According to the first aspect, it is possible to provide a nitride material having low electrical resistivity and the properties of a semiconductor that conducts electricity mainly through holes (e.g., it is possible to provide a diode that can operate at high temperatures (e.g., 100°C or higher) and has a high dielectric breakdown field strength (e.g., 2 MV / cm or higher)).

[0016] A second aspect of the present invention is the nitride material according to the first aspect, characterized in that α1 and β1 satisfy the following formula (3), and β2 satisfies the following formula (4): 0<α1 / β1<6 (3) 0<β2<0.52 (4)

[0017] According to the second aspect, it is possible to provide a nitride material having a lower electrical resistivity and the properties of a semiconductor that conducts electricity mainly through holes (e.g., it is possible to provide a diode that can operate at high temperatures (e.g., 100°C or higher) and has a high dielectric breakdown field strength (e.g., 2 MV / cm or higher)).

[0018] A third aspect of the present invention is the nitride material according to the first aspect, characterized in that monovalent B1 is contained in the largest amount compared to B1 with a valence other than monovalent, or monovalent B2 is contained in the largest amount compared to B2 with a valence other than monovalent.

[0019] According to the third aspect, it is possible to provide a nitride material having lower electrical resistivity and semiconducting properties.

[0020] A fourth aspect of the present invention resides in the nitride material according to the first aspect, characterized in that the crystal structure is a wurtzite crystal structure.

[0021] According to the fourth aspect, it is possible to provide a nitride material having lower electrical resistivity and semiconductor properties.

[0022] A fifth aspect of the present invention is the nitride material according to the first aspect, characterized in that α1 and β1 satisfy the following formulas (5) and (6): 1≦α1 / β1≦5 (5) 0<α1+β1≦0.3 (6)

[0023] According to the fifth aspect, it is possible to provide a nitride material having an even lower electrical resistivity and semiconductor properties.

[0024] A sixth aspect of the present invention resides in the nitride material according to any one of the first to fifth aspects, characterized in that the nitride material has an electrical resistivity of 10.0 Ω·cm or less.

[0025] According to the sixth aspect, it is possible to provide a nitride material having higher semiconductor properties.

[0026] A seventh aspect of the present invention resides in the nitride material according to any one of the first to fifth aspects, characterized in that the nitride material has an electrical resistivity of 1.0 Ω·cm or less.

[0027] According to the seventh aspect, it is possible to provide a nitride material having even higher semiconductor properties.

[0028] An eighth aspect of the present invention is a diode comprising the nitride material according to the first aspect and an n-type semiconductor material bonded to the nitride material.

[0029] According to the eighth aspect, it is possible to provide a diode having a high dielectric breakdown field strength (for example, 2 MV / cm or more).

[0030] A ninth aspect of the present invention is a transistor comprising the nitride material according to the first aspect and two n-type semiconductor materials bonded together, or comprising an n-type semiconductor material and two nitride materials according to the first aspect bonded to the n-type semiconductor material.

[0031] Here, the term "n-type semiconductor material" refers to a semiconductor material in which electrical conduction occurs due to negatively charged free electrons.

[0032] According to the ninth aspect, a transistor having a high dielectric breakdown field strength (for example, 2 MV / cm or more) can be provided.

[0033] The specification of Japanese Patent Application No. 2024-31899 is incorporated herein by reference.

[0034] FIG. 1 is a table showing the composition and electrical resistivity of the examples of embodiment 1. FIG. 2 is a graph showing the results of measurements of examples 1-1 to 1-3 using an X-ray diffractometer (XRD). FIG. 3 is a graph showing the relationship between binding energy and intensity for examples 1 and 3 of embodiment 1. FIG. 4 is a graph showing the relationship between binding energy and intensity for examples 1 and 3 of embodiment 1. ０．０５０ Au ０．０３７ Al ０．９１３ N, Mg ０．０７３ Au ０．０３６ Al０．８９１ N, Mg ０．１０１ Au ０．０３３ Al ０．８６６ N and Mg ０．３８８ Au ０．０８１ Al ０．５３１ 5 shows the relationship between the binding energy and intensity of Mg ０．０５０ Au ０．０３７ Al ０．９１３ FIG. 6 shows the relationship between the binding energy and intensity of N. ０．０６２５ Au ０．０６２５ Al ０．８７５ 7 is a diagram showing the band gap of N. FIG. 7 is a schematic diagram of a diode fabricated using nitride materials according to the first embodiment. FIG. ０．０６ Cu ０．０４ Al ０．９０ 9 is a graph showing the relationship between voltage and current for a diode made using N. ０．０２ Ag ０．０２ Al ０．９６ 10 is a table showing the composition and electrical resistivity of examples of the second embodiment. ０．０２ Al ０．９８ N), Au ０．０５ Al ０．９５ N and Au ０．１４ Al ０．８６ 12 is a graph showing the relationship between binding energy and intensity in Example 2-1. FIG. 13 is a graph showing the relationship between binding energy and intensity in Example 2-2. FIG. 14 is a graph showing the relationship between binding energy and intensity in Example 2-3. FIG. 15 is a graph showing the relationship between binding energy and intensity in Example 2-4. FIG. 16 is a graph showing the relationship between binding energy and intensity in Example 2-5. FIG. 17 is a graph showing the relationship between binding energy and intensity in Example 2-6. ０．０６２５ Al ０．９３７５ FIG. 1 is a diagram showing the band gap of N.

[0035] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the nitride material according to the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

[0036] (Embodiment 1) The nitride material of this embodiment is represented by the chemical formula A1 α１ B1β１ Al １－α１－β１ N or A1 α１ B1 β１ Ga １－α１－β１ N, and α1 and β1 satisfy the following formula (1): 0<α1+β1<1 (1)

[0037] (0<α1<1, 0<β1<1, A1 is at least one of Mg and Zn, and B1 is at least one of Au, Ag, and Cu.) This nitride material contains B1 with a monovalent atom. The valence of B1 can be detected by X-ray photoelectron spectroscopy (XPS) or the like.

[0038] The nitride material with such a structure has an electrical resistivity of 1.47×10 －６ It has a resistance of Ω·cm or more and 10.0 Ω·cm or less (i.e., it has electrical conductivity) and has the properties of a semiconductor in which electrical conduction is mainly achieved by holes.

[0039] Furthermore, it is preferable that α1 and β1 satisfy the following formula (3): 0<α1 / β1<6 (3) Such a nitride material has a lower electrical resistivity and high semiconductor properties.

[0040] Furthermore, among nitride materials having such a structure, the electrical resistivity is 1.47×10 －６ A resistivity of Ω·cm or more and 1.0 Ω·cm or less is preferred because it has higher semiconductor properties.

[0041] In addition, the crystal structure of the nitride material of this embodiment is preferably a wurtzite crystal structure, which has a lower electrical resistivity and high semiconductor properties.

[0042] Here, B1 may contain valences other than monovalent (e.g., 0, 2, 3, etc.), but a nitride material containing the most monovalent B1 compared to valences other than monovalent B1 is preferred. A nitride material having such a configuration has lower electrical resistivity and higher semiconductor properties.

[0043] Furthermore, the ratio of α1 to β1 is not particularly limited, but it is more preferable that it satisfies the following formulas (5) and (6): 1≦α1 / β1≦5 (5) 0<α1+β1≦0.3 (6) Nitride materials that satisfy these formulas have lower electrical resistivity and particularly high semiconductor properties.

[0044] Next, a method for manufacturing the above-mentioned nitride materials will be described. These nitride materials can be manufactured using a general manufacturing method such as physical vapor deposition (PDV) (sputtering, molecular beam epitaxy (MBE), evaporation, etc.) or chemical vapor deposition (CVD). Specifically, for example, nitrogen gas (N ２ ) atmosphere or nitrogen gas (N ２ The thin film can be manufactured by simultaneously sputtering a substrate (e.g., a silicon (Si) substrate) with a target composed of B1 (Au, Ag, Cu), a target composed of Al (Mg, Zn), and a target composed of aluminum (Al) or gallium (Ga) in a mixed atmosphere of B1 and argon gas (Ar) (gas pressure 1 Pa or less). Note that an alloy containing B1, Al, and Al or Ga in a predetermined ratio may also be used as the target.

[0045] EXAMPLES Using the following equipment, sputtering targets, etc., a plurality of thin films of the nitride material according to this embodiment having a thickness of 0.4 to 1.5 μm were produced on an n-type silicon substrate having a resistivity of 0.02 Ωcm. Multi-target simultaneous sputtering deposition apparatus (manufactured by Eiko Engineering Co., Ltd.) Au sputtering target material (concentration: 99.9%) Ag sputtering target material (concentration: 99.9%) Cu sputtering target material (concentration: 99.9%) Mg sputtering target material (concentration: 99.99%) Zn sputtering target material (concentration: 99.99%) Al sputtering target material (concentration: 99.999%) GaN sputtering target material (concentration: 99.99%) Gas: mixed gas of nitrogen (purity: 99.99995% or more) and argon gas (purity: 99.9999% or more) (mixing ratio 50:50) Substrate heating temperature: 500°C

[0046] The deposition experiment was carried out with the pressure in the sputtering chamber at 10 －５ The experiment was carried out after the target was lowered to a high vacuum of less than 100 Pa using a vacuum pump. In order to prevent the inclusion of impurities such as oxygen, the target surface was cleaned immediately after the target was attached and immediately before each film formation experiment.

[0047] The composition and electrical resistivity of each of the obtained nitride materials are shown in Figure 1. From this figure, it was found that the electrical resistivity of each nitride material was 1.0 Ω·cm or less.

[0048] The results of measurements taken with an X-ray diffractometer (XRD) for Examples 1-1 to 1-3 are shown in Figure 2. As can be seen from this figure, each of the nitride materials of Examples 1-1 to 1-3 was found to have a wurtzite crystal structure.

[0049] Furthermore, the relationship between the binding energy and intensity when the nitride materials of Examples 1-1 and 1-3 were measured by XPS (AXIS-165, manufactured by Shimadzu / KRATOS Seisakusho) is shown in FIG. ０．０５０ Au ０．０３７ Al ０．９１３ N (top row), Mg ０．０７３ Au ０．０３６ Al ０．８９１ N (second from the top), Mg ０．１０１ Au ０．０３３ Al ０．８６６ N (third from the top) and Mg ０．３８８ Au ０．０８１ Al ０．５３１ The results of measuring the valence of Mg in N (bottom row) using an X-ray diffraction (XRD) device are shown in Figure 4. ０．０５０ Au ０．０３７ Al ０．９１３ The results of measuring the valence of Au in N are shown in FIG. 5. The peaks shown in these figures indicate the binding energy of each element. From FIGS. 3 and 4, it was found that the binding energy of Mg2p coincides with that of Mg when the valence is 2 (+2). Similarly, from FIGS. 3 and 5, it was found that the binding energy of Au4f coincides with that of Au when the valence is 1 (+1). Therefore, the nitride materials of Examples 1-1 and 1-3, as well as Mg０．０５０ Au ０．０３７ Al ０．９１３ N and Mg ０．１０１ Au ０．０３３ Al ０．８６６ The valence of Mg contained in N is 2 (+2), and the nitride materials of Examples 1-1 and 1-3 and Mg ０．０５０ Au ０．０３７ Al ０．９１３ Au with a valence of N of 1 (+1) is replaced by Au with a valence of 0 (Au ０ ) and found to contain more of it than the

[0050] <Band gap> By simulation, the nitride material (Mg ０．０６２５ Au ０．０６２５ Al ０．８７５ The band gap of the ZnO-based SiO2-based SiO2-based SiO2 was calculated using the VASP (Vienna Ab initio Simulation Package) software, which employs a calculation method called first-principles calculation. First-principles calculation is a general term for electronic state calculation methods that do not use fitting parameters, etc., and is a method that can calculate the electronic state using only the atomic numbers and coordinates of each atom that constitutes a unit cell or molecule.

[0051] In the simulation of this embodiment, a wurtzite crystal structure of a supercell consisting of 16 aluminum atoms and 16 nitrogen atoms was used, which is obtained by doubling a unit cell consisting of two aluminum atoms and two nitrogen atoms in the a-axis, b-axis, and c-axis directions.

[0052] Calculations were performed on a wurtzite crystal structure in which one Al atom was replaced with an Mg atom and one Al atom was replaced with an Au atom in a unit cell consisting of 16 Al atoms and 16 N atoms. First-principles calculations were then performed on this wurtzite crystal structure model, with the atomic coordinates, cell volume, and cell shape all simultaneously varied to calculate the electronic state of the stable structure.

[0053] The results are shown in Figure 6. The horizontal axis "E-Ef" in this figure indicates the energy level based on the Fermi energy (Ef). From this result, it can be seen that there is an acceptor level, which is the density of state (DOS) derived from impurities (Mg, Au), at an energy level slightly higher than the valence band of AlN.

[0054] It is known that semiconductor materials that conduct electricity mainly through holes have a DOS (acceptor level) derived from impurities (added elements) at an energy level slightly higher than the valence band. ０．０６２５ Au ０．０６２５ Al ０．８７５ N) is found to have semiconductor properties.

[0055] <p-Type Semiconductor> The nitride material according to this embodiment is obtained by doping (adding) at least one of Mg and Zn and at least one of Au, Ag, and Cu to a base material, AlN or GaN. That is, the trivalent element Al or Ga contained in the base material, AlN or GaN, is doped with at least one of divalent elements Mg and Zn and at least one of monovalent elements Au, Ag, and Cu. As a result, holes are generated, and the nitride material according to this embodiment is a p-type semiconductor.

[0056] In fact, a diode 100 having the structure shown in Fig. 7 was fabricated. This diode 100 is composed of, from bottom to top, a lower electrode, an n-type Si film 120 having a thickness of 635 µm, and a nitride material (Mg ０．０６ Cu ０．０４ Al ０．９０ N or Zn ０．０２ Ag ０．０２ Al ０．９６ The lower electrode is composed of a 30-nm-thick Au thin film 110 and a 10-nm-thick Ti thin film 111 formed on the Au thin film 110.

[0057] The relationship between voltage and current was measured for these diodes using a KEYSIGHT B2985A Electrometer / High resistance meter. The results are shown in Figures 8 and 9. Figure 8 shows that the diodes functioned properly as diodes, and that the Mg ０．０６ Cu ０．０４ Al ０．９０ It was found that N is a p-type semiconductor. Also, from Figure 9, this diode functions properly as a diode, and Zn ０．０２ Ag ０．０２ Al ０．９６ It was found that N is a p-type semiconductor.

[0058] (Embodiment 2) The nitride material of this embodiment is represented by the chemical formula B2 β２ Al １－β２ N or chemical formula B2 β２ Ga １－β２ N, and β2 satisfies the following formula (2): 0<β2<1 (2) (B2 is at least one of Au, Ag, and Cu.)

[0059] The nitride material with such a structure has an electrical resistivity of 1.47×10 －６ The nitride material has a resistivity of 1.47×10 to 10.0 Ω cm (i.e., it is electrically conductive), and has the properties of a semiconductor that conducts electricity mainly through holes. －６ A resistivity of Ω·cm or more and 1.0 Ω·cm or less is preferred because it has higher semiconductor properties.

[0060] Furthermore, β2 preferably satisfies the following formula (4): 0<β2<0.52 (4) Such a nitride material has a lower electrical resistivity and exhibits high semiconductor properties. It is more preferable that β2 is in the range of 0<β2<0.2. A nitride material with β2 in this range exhibits an even lower electrical resistivity and exhibits high semiconductor properties.

[0061] Furthermore, the crystal structure of the nitride material of this embodiment is preferably a wurtzite crystal structure, which has a lower electrical resistivity and high semiconductor properties.

[0062] Here, B2 may contain B2 with a valence other than monovalent (for example, 0, 2, or 3), but a nitride material containing the most monovalent B2 compared to B2 with a valence other than monovalent is preferred. A nitride material having such a configuration has lower electrical resistivity and higher semiconductor properties.

[0063] Next, a method for manufacturing the above-mentioned nitride material will be described. These nitride materials can be manufactured using a general manufacturing method such as a sputtering method or a vapor deposition method. Specifically, for example, a method for manufacturing the nitride material using a nitrogen gas (N ２ ) atmosphere or nitrogen gas (N ２ The B2 target can be manufactured by simultaneously sputtering a target made of B2 (Au, Ag, Cu) and a target made of aluminum (Al) or gallium (Ga) onto a substrate (for example, a silicon (Si) substrate) in a mixed atmosphere of B2 and argon gas (Ar) (gas pressure of 1 Pa or less). Note that an alloy containing B2 and Al or Ga in a predetermined ratio may also be used as the target.

[0064] (Example) Using the following equipment and sputtering targets, thin films of the nitride material according to this embodiment with a thickness of 0.4 to 1.5 μm were fabricated on n-type silicon substrates with a resistivity of 0.02 Ωcm. Multi-target simultaneous sputtering deposition equipment (manufactured by Eiko Engineering Co., Ltd.) Au sputtering target material (concentration: 99.9%) Ag sputtering target material (concentration: 99.9%) Cu sputtering target material (concentration: 99.9%) Al sputtering target material (concentration: 99.999%) GaN sputtering target material (concentration: 99.99%) Gas: mixed gas of nitrogen (purity: 99.99995% or higher) and argon gas (purity: 99.9999% or higher) (mixing ratio 50:50) Substrate heating temperature: 500°C

[0065] The deposition experiment was carried out with the pressure in the sputtering chamber at 10－５ The experiment was carried out after the target was lowered to a high vacuum of less than 100 Pa using a vacuum pump. In order to prevent the inclusion of impurities such as oxygen, the target surface was cleaned immediately after the target was attached and immediately before each film formation experiment.

[0066] The composition and electrical resistivity of each of the obtained nitride materials are shown in Figure 10. From this figure, it was found that the electrical resistivity of each nitride material was 1.0 Ω·cm or less.

[0067] In addition, Example 2-1 (Au ０．０２ Al ０．９８ N), Au ０．０５ Al ０．９５ N and Au ０．１４ Al ０．８６ The results of the measurement of N by an X-ray diffractometer (XRD) are shown in FIG. 11. As can be seen from this figure, in Example 2-1, Au ０．０５ Al ０．９５ N and Au ０．１４ Al ０．８６ Each nitride material of N was found to have a wurtzite crystal structure.

[0068] Furthermore, the relationship between the binding energy and the intensity when the nitride materials of Examples 2-1 and 2-2 were measured by XPS (AXIS-165, manufactured by Shimadzu / KRATOS Seisakusho) is shown in FIGS. 12 and 13, respectively.

[0069] From FIG. 12, it was found that the nitride material of Example 2-1 contained monovalent Au, and that the amount of monovalent Au was greater than that of Au with other valences (zerovalent Au).

[0070] Furthermore, it was found from FIG. 13 that the nitride material of Example 2-2 contained monovalent Ag, and that the amount of monovalent Ag was greater than that of Ag with other valences (zerovalent Ag).

[0071] <Band gap> By simulation, the nitride material (Au ０．０６２５ Al ０．９３７５ The band gap of the semiconductor layer (N) was calculated. For this simulation, software called VASP was used, as in the first embodiment.

[0072] In the simulation of this embodiment, a wurtzite crystal structure of a supercell consisting of 16 aluminum atoms and 16 nitrogen atoms was used, which is obtained by doubling a unit cell consisting of two aluminum atoms and two nitrogen atoms in the a-axis, b-axis, and c-axis directions.

[0073] The calculations were performed using a wurtzite crystal structure in which one Al atom was replaced with an Au atom in a unit cell consisting of 16 Al atoms and 16 N atoms. The atomic coordinates, cell volume, and cell shape of this wurtzite crystal structure model were all simultaneously varied to perform first-principles calculations and calculate the electronic state of a stable structure.

[0074] The results are shown in Figure 14. In this figure, the horizontal axis "E-Ef" indicates the energy level based on the Fermi energy (Ef). From this result, it can be seen that there is an acceptor level, which is the density of state (DOS) derived from the impurity (Au), at an energy level slightly higher than the valence band of AlN.

[0075] As mentioned above, it is known that semiconductor materials have DOS (acceptor levels) derived from impurities (added elements) at an energy level slightly higher than the valence band. ０．０６２５ Al ０．９３７５ N) is found to have semiconductor properties.

[0076] The nitride material according to this embodiment is obtained by doping (adding) at least one of Au, Ag, and Cu to the base material AlN or GaN. That is, the trivalent element Al or Ga contained in the base material AlN or GaN is doped with at least one of monovalent elements Au, Ag, and Cu. As a result, holes are generated, and the nitride material according to this embodiment is a p-type semiconductor.

[0077] Other Embodiments In the first embodiment described above, Mg or Zn was used as Al, but the present invention is not limited to this. For example, the nitride material may be configured so that Al contains Mg and Zn in a predetermined ratio. Even when the nitride material is configured in this way, the same effects as those of the first embodiment can be obtained.

[0078] Similarly, in the first and second embodiments, Au, Ag, or Cu is used as B1 and B2, but the present invention is not limited thereto. For example, the nitride material may be configured so that B1 or B2 contains two of Au, Ag, and Cu in a predetermined ratio, or the nitride material may be configured so that B1 or B2 contains Au, Ag, and Cu in a predetermined ratio. Even when the nitride material is configured in this way, the same effects as those of the first embodiment can be obtained.

[0079] Furthermore, a diode may be constructed using the nitride material according to the present invention. The configuration of the diode is not particularly limited as long as it uses the nitride material according to the present invention, and known configurations can be used. For example, a diode may be constructed using the nitride material according to the present invention and an n-type semiconductor material (a semiconductor material in which electrical conduction occurs due to negatively charged free electrons) bonded to the nitride material. A diode with such a configuration has a high breakdown field strength (e.g., 2 MV / cm or more) compared to a diode using a semiconductor material containing Si. Examples of n-type semiconductor materials that can be used include n-type GaN, n-type AlGaN, and n-type SiGaN, which have a high breakdown field strength (e.g., 2 MV / cm or more).

[0080] Furthermore, a transistor may be constructed using the nitride material according to the present invention. The configuration of the transistor is not particularly limited, and known configurations can be used, as long as the transistor uses the nitride material according to the present invention. Examples of transistor configurations include a transistor constructed of the nitride material according to the present invention and two n-type semiconductor materials (semiconductor materials in which electrical conduction occurs due to negatively charged free electrons) bonded to sandwich the nitride material, or a transistor constructed of an n-type semiconductor material and two nitride materials according to the present invention bonded to sandwich the n-type semiconductor material. A transistor constructed in this manner has a high breakdown field strength (e.g., 2 MV / cm or more) compared to a transistor using a p-type semiconductor material using Si. Examples of n-type semiconductor materials that can be used include n-type GaN, n-type AlGaN, and n-type SiGaN, which have a high breakdown field strength (e.g., 2 MV / cm or more).

Claims

1. Chemical formula A1 α１ B1 β１ Al １－α１－β１ N or chemical formula A1 α１ B1 β１ Ga １－α１－β１ N, and α1 and β1 satisfy the following formula (1), or chemical formula B2 β２ Al １－β２ N or chemical formula B2 β２ Ga １－β２ β2 satisfies the following formula (2), and B1 and B2 include monovalent ones: 0<α1+β1<1 (1) 0<β2<1 (2) (0<α1<1, 0<β1<1, A1 is at least one of Mg and Zn, and B1 and B2 are at least one of Au, Ag, and Cu.) 2. The nitride material according to claim 1, wherein α1 and β1 satisfy the following formula (3), and β2 satisfies the following formula (4): 0<α1 / β1<6 (3) 0<β2<0.52 (4) 3. The nitride material according to claim 1, characterized in that monovalent B1 is contained in the largest amount compared to B1 with a valence other than monovalent, or monovalent B2 is contained in the largest amount compared to B2 with a valence other than monovalent.

4. The nitride material according to claim 1, characterized in that the crystal structure is a wurtzite crystal structure.

5. The nitride material according to claim 1, wherein the α1 and β1 satisfy the following formulas (5) and (6): 1≦α1 / β1≦5 (5) 0<α1+β1≦0.3 (6) 6. The nitride material according to any one of claims 1 to 5, characterized in that the electrical resistivity is 10.0 Ω·cm or less.

7. The nitride material according to any one of claims 1 to 5, characterized in that the electrical resistivity is 1.0 Ω·cm or less.

8. A diode comprising the nitride material according to claim 1 and an n-type semiconductor material bonded to said nitride material.

9. A transistor comprising the nitride material according to claim 1 and two n-type semiconductor materials bonded to said nitride material, or comprising an n-type semiconductor material and two nitride materials according to claim 1 bonded to said n-type semiconductor material.

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