CN118621440B

CN118621440B - Semiconductor material, semiconductor device and preparation method

Info

Publication number: CN118621440B
Application number: CN202411098062.0A
Authority: CN
Inventors: 查显弧; 张道华; 万玉喜; 李翔
Original assignee: Shenzhen Pinghu Laboratory
Current assignee: Shenzhen Pinghu Laboratory
Priority date: 2024-08-12
Filing date: 2024-08-12
Publication date: 2024-11-22
Anticipated expiration: 2044-08-12
Also published as: CN118621440A

Abstract

The present application discloses a semiconductor material, a semiconductor device and a preparation method. The chemical formula of the semiconductor material is β‑(Rh _x Ga _1‑x ) _2y O ₃ , wherein 0＜x≤0.5, and 0.9≤y≤1.1. The above semiconductor material is obtained by solid dissolving Rh in β‑Ga ₂ O _3. After Rh is solid dissolved in β‑Ga ₂ O ₃ , the electron orbits of Rh and O interact to form a new valence band top, and the new valence band top energy level is significantly higher than the valence band top energy level of β‑Ga ₂ O _3. The new valence band top has a steep dispersion relation, and the steep dispersion relation represents a lower hole effective mass, and the low hole effective mass will reduce the occurrence of hole self-capture and polarization phenomena. The β‑(Rh _x Ga _1‑x ) _2y O ₃ of the present application is expected to solve the p-type doping problem of β‑Ga ₂ O ₃ , and can be used to prepare power semiconductor devices with better performance.

Description

Semiconductor material, semiconductor device and preparation method

Technical Field

The present application relates to the field of semiconductor technology, and in particular, to a semiconductor material, a semiconductor device, and a method for manufacturing the semiconductor material and the semiconductor device.

Background

The power characteristics of a semiconductor device are positively correlated with the band gap and carrier mobility of the semiconductor material. Gallium oxide has ultra-wideband band gap (about 4.9 eV) and mature preparation method, and is an ideal material for preparing high-power semiconductor devices. Beta-phase gallium oxide (beta-Ga ₂O₃) has the most stable crystal structure, and can be applied to the fields of high temperature, high pressure, high power and the like. Similar to various oxides, the valence band top of beta-Ga ₂O₃ is mainly contributed by the 2p orbit of oxygen atoms, the orbit energy level position is low, and the dispersion relation is flat. Common adjacent elements (such as Mg, zn and the like) are doped with acceptor energy levels more than 1 eV, so that hole carriers are difficult to excite and form. The flat dispersion relationship predicts high hole effective mass and is prone to hole self-trapping and polarization. Therefore, it is necessary to modulate and modify β -Ga ₂O₃, raise its valence band top level position and improve dispersion relations in order to achieve p-type doping.

Disclosure of Invention

The application discloses a semiconductor material, a semiconductor device and a preparation method, wherein a novel wide-bandgap semiconductor material beta- (Rh _xGa_1-x)_2yO₃) is obtained through Rh solid solution beta-Ga ₂O₃, the top energy level position of a valence band is improved, the top dispersion relation of the valence band is improved, p-type doping is hopefully realized, and the performance of a semiconductor power device is improved.

In order to achieve the above purpose, the present application provides the following technical solutions:

In a first aspect, the present application provides a semiconductor material having the chemical formula β - (Rh _xGa_1-x)_2yO₃), where 0 < x.ltoreq.0.5 and 0.9.ltoreq.y.ltoreq.1.1.

The semiconductor material is prepared from a novel wide-bandgap semiconductor material beta- (Rh _xGa_1-x)_2yO₃) through Rh solid-solution beta-Ga ₂O₃, wherein x is more than 0 and less than or equal to 0.5, y is more than or equal to 0.9 and less than or equal to 1.1.Rh is dissolved in beta-Ga ₂O₃, a new valence band top is formed by electron orbit action of Rh and O, and the new valence band top energy level is obviously increased compared with the valence band top energy level of beta-Ga ₂O₃.

In some embodiments, the semiconductor material β - (Rh _xGa_1-x)_2yO₃) has x in the range of 0.125.ltoreq.x.ltoreq.0.25 and y in the range of 0.9.ltoreq.y.ltoreq.1.1 when the atomic percentage of Rh in the β - (Rh _xGa_1-x)_2yO₃) material is 0.125.ltoreq.x.ltoreq.0.25, the β - (Rh _xGa_1-x)_2yO₃) material has a smaller hole effective mass and a higher carrier mobility, which is more advantageous for achieving p-type doping.

In some embodiments, the crystalline structure of the semiconductor material is a monoclinic crystalline structure. The structure is the most stable crystal structure of beta-Ga ₂O₃, and when Rh is dissolved in beta-Ga ₂O₃ in the structure, the obtained solid solution beta- (Rh _xGa_1-x)_2yO₃) is also more stable.

In some embodiments, the semiconductor material has a mixing enthalpy of 0 eV/cation to 0.14 eV/cation. The obtained beta- (Rh _xGa_1-x)_2yO₃) has lower mixing enthalpy, which indicates that the beta- (Rh _xGa_1-x)_2yO₃) has better structural stability.

In some embodiments, the semiconductor material has a hole effective mass of 2m _e-7 m_e. The effective mass of the hole of the beta- (Rh _xGa_1-x)_2yO₃) is smaller, the occurrence of the phenomena of hole self-trapping and the like can be reduced, and the p-type doping can be realized.

In some embodiments, the difference between the top energy level of the valence band of the semiconductor material and beta-Ga ₂O₃ is 1.1-eV or greater. After Rh is dissolved in beta-Ga ₂O₃ in a solid way, the electron orbitals of Rh and O form a new valence band top, and the energy level of the new valence band top is obviously increased compared with that of beta-Ga ₂O₃.

In some embodiments, the semiconductor material has an energy band gap value of 3.77 eV-4.10 eV. After Rh is dissolved in beta-Ga ₂O₃ in a solid way, beta- (Rh _xGa_1-x)_2yO₃ still has a wider band gap value, belongs to a wide band gap semiconductor, and is beneficial to preparing a high-power semiconductor device.

In a second aspect, the present application provides a semiconductor device comprising a substrate and a semiconductor layer made of the semiconductor material according to the first aspect.

In some embodiments, the semiconductor layer is a p-type semiconductor layer or an n-type semiconductor layer. The beta- (Rh _xGa_1-x)_2yO₃) semiconductor layer can realize p-type doping or n-type doping, and the performance of the semiconductor power device is improved.

In some embodiments, the crystal orientation of the substrate is [010] crystal orientation. By adopting the substrate with the crystal orientation of [010], rh grows along the b axis, the obtained beta- (Rh _xGa_1-x)_2yO₃) semiconductor layer has lower energy, a material system is more stable, the effective mass of holes is lower, and p-type doping is more facilitated.

In a third aspect, the present application provides a method for manufacturing a semiconductor device, comprising:

Preheating a substrate: placing a beta-Ga ₂O₃ substrate in a growth cavity and preheating;

And (3) growing: introducing source materials comprising an O source, a Ga source and a Rh source into the growth cavity, and growing a beta- (Rh _xGa_1-x)_2yO₃) semiconductor layer on the beta-Ga ₂O₃ substrate through reaction, wherein x is more than 0 and less than or equal to 0.5, and y is more than or equal to 0.9 and less than or equal to 1.1.

In some embodiments, the beta-Ga ₂O₃ substrate has a [010] crystal orientation.

In some embodiments, the temperature of the Ga source introduced is 800 ℃ to 900 ℃ and the temperature of the Rh source introduced is ≡1500 ℃. The high temperature facilitates adjustment of the evaporation rates of the Ga source and the Rh source, and thus the growth rate of beta- (Rh _xGa_1-x)_2yO₃) on the substrate.

In some embodiments, the growth temperature of the beta- (Rh _xGa_1-x)_2yO₃) is 600-800 ℃ by controlling the growth temperature, a more desirable beta- (Rh _xGa_1-x)_2yO₃) semiconductor material can be obtained.

Drawings

Fig. 1 is a schematic flow chart of a method for manufacturing a semiconductor device according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a molecular beam epitaxy method for preparing β - (Rh _xGa_1-x)_2yO₃) according to an embodiment of the present application;

FIG. 3 is a graph of the highest valence band real space electron local density of states for providing β - (Rh _xGa_1-x)_2yO₃) in accordance with an embodiment of the present application;

FIG. 4 is a schematic diagram of a unit cell configuration of β - (Rh _xGa_1-x)_2yO₃) provided in an embodiment of the present application;

FIG. 5 is a diagram showing the unit cell parameters of β - (Rh _xGa_1-x)_2yO₃) provided in an embodiment of the present application;

FIG. 6 is a graph showing calculated mixing enthalpy and corresponding volume of a single molecular formula for β - (Rh _xGa_1-x)_2yO₃) in accordance with an embodiment of the present application;

FIG. 7 is a diagram of the energy band structure of β - (Rh _xGa_1-x)_2yO₃) provided by an embodiment of the present application;

FIG. 8 is a graph showing the average hole effective mass of β - (Rh _xGa_1-x)_2yO₃) provided by an embodiment of the application;

fig. 9 is an energy band alignment diagram of β - (Rh _xGa_1-x)_2yO₃) provided in an embodiment of the present application.

Detailed Description

First, an application scenario is introduced. The high-power semiconductor device is important to the development of technologies such as new energy automobiles, smart grids and the like, and can improve the conversion efficiency of energy sources. The power characteristics of a semiconductor device are positively correlated with the band gap and carrier mobility of the semiconductor material. Gallium oxide has ultra-wideband band gap (about 4.9 eV) and mature preparation method, and is an ideal material for preparing high-power semiconductor devices. The reported gallium oxide has five crystal configurations, and beta-phase gallium oxide (beta-Ga ₂O₃, space group is monoclinic C2/m) is the most stable crystal structure, and can be applied to the fields of high temperature, high pressure, high power and the like. The current research on gallium oxide is mostly based on this crystal configuration.

Similar to various oxides, the valence band top of beta-Ga ₂O₃ is mainly contributed by the 2p orbit of oxygen atoms, the orbit energy level position is low, and the dispersion relation is flat. Common adjacent elements (such as Mg, zn and the like) are doped with acceptor energy levels more than 1eV, so that hole carriers are difficult to excite and form. The flat dispersion relationship predicts high hole effective mass and is prone to hole self-trapping and polarization. Due to the lack of p-type doping, the current semiconductor devices of beta-Ga ₂O₃ are mostly based on unipolar transport of Schottky junctions and bipolar transport of p-n heterojunctions. For the same semiconductor material, the barrier of the schottky junction formed with metal is lower than the p-n junction barrier height, and the power characteristics of the schottky junction device are significantly lower than the latter. For p-n heterojunction devices composed of n-type beta-Ga ₂O₃ and other p-type oxides (such as NiO), interface states caused by lattice mismatch often become dominant mechanisms of reverse leakage, and the power characteristics of the corresponding devices are still significantly lower than the theoretical limit of beta-Ga ₂O₃ materials. Therefore, it is necessary to modulate and modify β -Ga ₂O₃, raise its valence band top level position and improve dispersion relations in order to achieve p-type doping.

For metal oxides, solid solution of metal cations with full electron shells can be used to raise the valence band top energy level and increase the curvature of dispersion relation. For beta-Ga ₂O₃, in the prior study, bi is adopted to carry out solid solution on the configuration beta- (Bi _xGa_1-x)₂O₃) of Bi solid-solution beta-Ga ₂O₃, and as the difference of Bi and Ga atomic radii is large, the corresponding mixing enthalpy is high, the solid solution with higher concentration is difficult to carry out, the solid solution is likely to be subject to phase decomposition at high temperature, and the band gap value is small.

Based on the above problems, the embodiment of the application provides a novel wide band gap semiconductor material beta- (Rh _xGa_1-x)_2yO₃) obtained by Rh solid solution beta-Ga ₂O₃, compared with the existing scheme adopting Bi solid solution beta-Ga ₂O₃, the novel wide band gap semiconductor material beta- (Rh _xGa_1-x)_2yO₃) is hopeful to realize n-type and p-type doping of the same type of wide band gap semiconductor material based on the novel semiconductor beta- (Rh _xGa_1-x)_2yO₃, and the performance of a semiconductor power device is improved.

In a first aspect, embodiments of the present application provide a semiconductor material having a chemical formula β - (Rh _xGa_1-x)_2yO₃), where 0 < x.ltoreq.0.5 and 0.9.ltoreq.y.ltoreq.1.1.

The novel wide-bandgap semiconductor material beta- (Rh _xGa_1-x)_2yO₃) is obtained by the metal rhodium Rh solid-solution beta-Ga ₂O₃, wherein x is more than 0 and less than or equal to 0.5, y is more than or equal to 0.9 and less than or equal to 1.1.Rh is dissolved in beta-Ga ₂O₃, a novel valence band top is formed by electron orbit action of Rh and O, and the novel valence band top energy level is obviously increased compared with the valence band top energy level of beta-Ga ₂O₃.

The solid solution beta- (Rh _xGa_1-x)_2yO₃) has the advantages of high stability, wide band gap, high valence band top energy level and steep valence band top dispersion relation, is easy to realize p-type doping, and can improve the performance of a semiconductor power device.

In the β - (Rh _xGa_1-x)_2yO₃, x and y are atom percentages, wherein 0 < x is less than or equal to 0.5, and 0.9 is less than or equal to 1.1. Exemplary, x may be a value of 0.0625, 0.125, 0.1875, 0.25, 0.3125, 0.375, 0.4375, 0.5, or any two or more, and the specific value is not limited, y may be a value of 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.02, 1.04, 1.06, 1.08, 1.1, or any two or more, and the specific value is not limited.

In some embodiments, 0.125.ltoreq.x.ltoreq.0.25, and y is more than or equal to 0.9 and less than or equal to 1.1. Illustratively, x may be a value of 0.125, 0.1875, 0.25, etc., or any two of the above, and the specific values are not limited. y may be 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.02, 1.04, 1.06, 1.08, 1.1, etc. or any numerical value between any two above, and the specific numerical value is not limited. When the atomic percentage of Rh in the beta- (Rh _xGa_1-x)_2yO₃) material is 0.125-0.25, the beta- (Rh _xGa_1-x)_2yO₃) material has smaller effective mass of holes and higher carrier mobility, and p-type doping is more facilitated.

In some embodiments, the semiconductor material has a mixing enthalpy of 0 eV/cation to 0.14 eV/cation. The mixing enthalpy of the semiconductor material may be 0 eV/cation、0.02 eV/cation、0.04 eV/cation、0.06 eV/cation、0.08 eV/cation、0.10 eV/cation、0.12 eV/cation、0.14 eV/cation or any value between any two values above, and the specific value is not limited. The beta- (Rh _xGa_1-x)_2yO₃) obtained by the method has lower mixing enthalpy, which shows that the beta- (Rh _xGa_1-x)_2yO₃) has better structural stability, is favorable for realizing the solid solution of high-concentration Rh, and is not easy to generate phase decomposition at high temperature.

In some embodiments, the semiconductor material has a hole effective mass of 2m _e-7 m_e. Illustratively, the hole effective mass of the semiconductor material may be 2 m_e-7 m_e、2 m_e-6 m_e、2 m_e-5.5 m_e、2 m_e-5 m_e、2 m_e-4.5 m_e、2 m_e-4 m_e、2 m_e-3.5 m_e、2 m_e-3 m_e, etc., and the specific numerical interval is not limited. In one possible implementation, the hole effective mass of the semiconductor material is 2.22 m _e-4 m_e. The effective mass of the hole of the beta- (Rh _xGa_1-x)_2yO₃) is smaller, the occurrence of the phenomena of hole self-trapping and the like can be reduced, and the p-type doping can be realized.

In some embodiments, the difference between the top energy level of the valence band of the semiconductor material and the beta-Ga ₂O₃ is 1.1-eV or greater. Illustratively, the difference between the valence band top energy levels of the semiconductor material and β -Ga ₂O₃ may be 1.1 eV, 1.2 eV, 1.3 eV, 1.4 eV, 1.5 eV, 1.6 eV, 1.8 eV, 1.9 eV, 2.0 eV, 2.1 eV, 2.2 eV, 2.3 eV, etc., and specific numerical intervals are not limited. After Rh is dissolved in beta-Ga ₂O₃ in a solid way, the electron orbitals of Rh and O form a new valence band top, and the energy level of the new valence band top is remarkably increased compared with that of beta-Ga ₂O₃.

In some embodiments, the semiconductor material has a band gap value of 3.77 eV-4.10 eV. Illustratively, the band gap value of the semiconductor material may be 3.77 eV, 3.78 eV, 3.80 eV, 3.88 eV, 3.95 eV, 4.02 eV, 4.07 eV, 4.10 eV, or any value therebetween, and the specific value is not limited. After Rh is dissolved in beta-Ga ₂O₃ in a solid way, beta- (Rh _xGa_1-x)_2yO₃ still has a wider band gap value, belongs to a wide band gap semiconductor, and is beneficial to preparing a high-power semiconductor device.

In a second aspect, embodiments of the present application provide a semiconductor device comprising a substrate and a semiconductor layer made of a semiconductor material as in the first aspect.

In a third aspect, an embodiment of the present application provides a method for manufacturing a semiconductor device, and fig. 1 is a schematic flow chart of the method for manufacturing a semiconductor device according to the embodiment of the present application, which specifically includes the following steps:

S101, preheating a substrate: placing a beta-Ga ₂O₃ substrate in a growth cavity and preheating;

S102, growing: introducing source materials comprising an O source, a Ga source and a Rh source into a growth cavity, and growing a beta- (Rh _xGa_1-x)_2yO₃) semiconductor layer on a beta-Ga ₂O₃ substrate through reaction, wherein x is more than 0 and less than or equal to 0.5, and y is more than or equal to 0.9 and less than or equal to 1.1.

Fig. 2 is a schematic diagram of a preparation of β - (Rh _xGa_1-x)_2yO₃) by a molecular beam epitaxy method according to an embodiment of the present application, as shown in fig. 2, a specific flow of a preparation of a semiconductor device by a molecular beam epitaxy (Molecular Beam Epitaxy, MBE) method according to the present application is as follows:

(1) Preheating a substrate: the beta-Ga ₂O₃ substrate is placed in an MBE growth chamber, and the temperature is gradually increased to about 600-700 ℃ to remove surface pollutants.

(2) The growth process comprises the following steps: ① Introducing an oxygen source, and controlling the oxygen partial pressure within the range of 10 ^-5-10^-6 Torr to ensure sufficient oxidation; an atomic O (O source) is generated by a high-purity O ₂ source through a radio-frequency plasma source, and the power of the radio-frequency source is controlled between 200W and 300W. ② And heating a growth source (Ga source and Rh source), generating a molecular beam by electron beam evaporation of a source material, carrying out energy exchange on the molecular beam and a beta-Ga ₂O₃ substrate, and then carrying out surface adsorption, migration, nucleation and growth film formation to obtain a beta- (Rh _xGa_1-x)_2yO₃ semiconductor layer ③, detecting and adjusting the evaporation rates of Ga and Rh by a beam detector, wherein the initial rate is controlled in the range of 0.1-1A/s.

(3) And (3) post-growth treatment: gradually reducing the temperature of the substrate, and avoiding thermal stress and cracks caused by quenching; can be annealed, and the low-temperature annealing (such as 400-600 ℃) can improve the crystal quality.

It should be noted that the semiconductor device of the present application may also be manufactured by using various modified physical and chemical vapor deposition epitaxial growth methods, such as pulse laser deposition, atomized chemical vapor deposition, and the like.

In some embodiments, the crystal orientation of the β -Ga ₂O₃ substrate is the [010] crystal orientation. Beta- (Rh _xGa_1-x)_2yO₃) with smaller effective cavity quality benefits from the state density of O-Rh-O delocalization along the b axis, therefore, the experimental preparation adopts [010] crystal orientation of beta-Ga ₂O₃ as an epitaxial substrate for beta- (Rh _xGa_1-x)_2yO₃ film growth, and the crystal orientation of the beta- (Rh _xGa_1-x)_2yO₃) semiconductor material is also [010] crystal orientation, namely, the [010] crystal orientation of the substrate is consistent with the crystal orientation of beta- (Rh _xGa_1-x)_2yO₃, so that the growth of beta- (Rh _xGa_1-x)_2yO₃) is facilitated, and the effective cavity quality of the obtained beta- (Rh _xGa_1-x)_2yO₃) is smaller.

In the configuration of β - (Rh _xGa_1-x)_2yO₃), the configuration of Rh distributed along the b-axis has lower energy and the system is more stable, at x=0.1875, the configuration hole effective mass occupied by Rh along the b-axis portion in β - (Rh _xGa_1-x)_2yO₃) is 3.56 m _e, and the hole effective mass occupied by Rh along the b-axis is 2.70 m _e.

Fig. 3 is a diagram of the real space electron local density of the highest valence band of β - (Rh _xGa_1-x)_2yO₃) provided in the embodiment of the present application, as shown in fig. 3, the electron density of the highest valence band of β - (Rh _0.0625Ga_0.9375)₂O₃) is (a) shown in fig. 3, the electron density of the highest valence band of β - (Rh _0.125Ga_0.875)₂O₃) is (b) shown in fig. 3, the electron density of the highest valence band of β - (Rh _0.1825Ga_0.8125)₂O₃) is (c) shown in fig. 3, the electron density of the highest valence band of β - (Rh _0.25Ga_0.75)₂O₃) is (d) shown in fig. 3, wherein the equipotential surface of the electron density is set to be 0.001 e/³. Rh is more prone to be distributed along the b-axis.

In some embodiments, the temperature of the introduced Ga source is 800-900 ℃, and the temperature of the introduced Rh source is ≡1500 ℃. The high temperature facilitates adjustment of the evaporation rates of the Ga source and the Rh source, and thus the growth rate of beta- (Rh _xGa_1-x)_2yO₃) on the substrate.

In one possible implementation, the Ga source is heated with a high Wen Yuanlu and the temperature is controlled in the range 800-900 ℃. Rh has a higher melting point and a slower evaporation rate, is heated by adopting a plurality of high Wen Yuanlu, is generally at a temperature of more than 1500 ℃, and is evaporated by matching with an electron beam, so that the problem of insufficient evaporation rate of Rh is solved.

In some embodiments, the suitable growth temperature of beta- (Rh _xGa_1-x)_2yO₃) is 600-800 deg.C. The growth temperature of the present application is optimized from low to high temperatures.

The structure and parameters of beta- (Rh _xGa_1-x)_2yO₃ are explained above, and the beta- (Rh _xGa_1-x)_2yO₃) of the present application will be further described in detail with reference to specific examples.

Examples 1 to 8

Examples 1-8 are each a semiconductor material having a molecular formula of β-(Rh_0.0625Ga_0.9375)₂O₃、β-(Rh_0.125Ga_0.875)₂O₃、β-(Rh_0.1825Ga_0.8125)₂O₃、β-(Rh_0.25Ga_0.75)₂O₃、β-(Rh_0.3125Ga_0.6875)₂O₃、β-(Rh_0.375Ga_0.625)₂O₃、β-(Rh_0.4375Ga_0.5625)₂O₃、β-(Rh_0.5Ga_0.5)₂O₃.

The application provides the unit cell configurations of the semiconductor materials of the examples 4 and 8, calculates the unit cell parameters of the semiconductor materials of the examples 1 to 8, calculates the mixing enthalpy and the corresponding volume of a single molecular formula of the semiconductor materials of the examples 1 to 8, obtains the energy band structure diagrams of the semiconductor materials of the examples 1 to 8, calculates the average hole effective mass of the semiconductor materials of the examples 1 to 8, and obtains the energy band alignment diagrams of the semiconductor materials of the examples 1 to 8.

Fig. 4 is a schematic diagram showing the cell configuration of β - (Rh _xGa_1-x)_2yO₃) provided in examples 4 and 8, wherein (a) in fig. 4 is the cell configuration of β - (Rh _0.25Ga_0.75)₂O₃, and (b) in fig. 4 is the cell configuration of β - (Rh _0.5Ga_0.5)₂O₃. As shown in fig. 4, two non-allelic Ga atoms exist in the β -Ga ₂O₃,β-Ga₂O₃ cell for Rh solid solution, one located at the octahedral center composed of oxygen atoms, and the other located at the tetrahedral center composed of oxygen atoms.

Fig. 5 is a graph of the cell parameters of β - (Rh _xGa_1-x)_2yO₃) provided in examples 1-8, where (a) in fig. 5 is the cell parameter on the a-axis, (b) in fig. 5 is the cell parameter on the b-axis, and (c) in fig. 5 is the cell parameter on the c-axis based on supercells of 1 x2 β -Ga ₂O₃, the cell configuration at different x values was examined, the difference for each cell x was 0.0625. The lattice parameter of β - (Rh _xGa_1-x)_2yO₃) as shown in fig. 5, the cell parameters increased in different directions, but the percentage increase was very small, due to the very close atomic radii of Rh and Ga.

In the embodiment of the application, the stability of the solid solution beta- (Rh _xGa_1-x)_2yO₃) can be inspected through the mixing enthalpy value, and the calculation formula of the mixing enthalpy value of the semiconductor material is as follows:

Wherein, The energy of the solid solution is that of the solid solution,AndCorresponding to the most stable configuration energies of Ga ₂O₃ and Rh ₂O₃, respectively.Is the number of cations in the solid solution configuration.

As can be seen from the graph, the unit volume of both beta- (Rh _xGa_1-x)_2yO₃ and beta- (Bi _xGa_1-x)₂O₃ increases with increasing x, but the former increases more slowly, the latter increases more rapidly. The enthalpy of mixing of beta- (Bi _xGa_1-x)₂O₃ reaches about 0.14 eV/cation at a Bi content of x=0.125, the high mixing enthalpy value indicates that a higher concentration of solid solution is difficult, whereas the mixing enthalpy value reaches 0.14 eV/cation at an Rh content of x=0.5, indicating that β - (Rh _xGa_1-x)_2yO₃ can achieve a higher Rh content of solid solution, and that the corresponding β - (Rh _0.5Ga_0.5)₂O₃ volume is even significantly smaller than that of β - (Bi _0.125Ga_0.875)₂O₃).

In addition, as can be seen from fig. 6, the mixed enthalpy value of the β - (Rh _xGa_1-x)_2yO₃) semiconductor material is about 0 eV/position-0.14 eV/position, specifically, when x=0.0625, the mixed enthalpy value of β - (Rh _xGa_1-x)_2yO₃ is about 0.015 eV/position, when x=0.125, the mixed enthalpy value of β - (Rh _xGa_1-x)_2yO₃ is about 0.03 eV/position, when x=0.1875, the mixed enthalpy value of β - (Rh _xGa_1-x)_2yO₃ is about 0.046 eV/position, when x=0.25, the mixed enthalpy value of β - (Rh _xGa_1-x)_2yO₃ is about 0.06 eV/position, when x=0.3125, the mixed enthalpy value of β - (Rh _xGa_1-x)_2yO₃ is about 0.082 eV/position, when x=0.375, the mixed enthalpy value of β - (Rh _xGa_1-x)_2yO₃ is about 0.1 eV/position, when x=0.4375, the mixed enthalpy value of β - (Rh _xGa_1-x)_2yO₃ is about 0.12/position, when x=0.25, and when x=0.25, the solid solution concentration of β - (Rh _xGa_1-x)_2yO₃) is about 0.06/position, which is not easy to be decomposed at a high solid solution.

Fig. 7 is a diagram showing the band structure of β - (Rh _xGa_1-x)_2yO₃) provided in examples 1 to 8, wherein (a) in fig. 7 is a diagram showing the band structure of β - (Rh _0.0625Ga_0.9375)₂O₃), (b) in fig. 7 is a diagram showing the band structure of β - (Rh _0.125Ga_0.875)₂O₃), (c) in fig. 7 is a diagram showing the band structure of β - (Rh _0.1825Ga_0.8125)₂O₃, d) in fig. 7 is a diagram showing the band structure of β - (Rh _0.25Ga_0.75)₂O₃, e) in fig. 7 is a diagram showing the band structure of β - (Rh _0.3125Ga_0.6875)₂O₃, f) in fig. 7 is a diagram showing the band structure of β - (Rh _0.375Ga_0.625)₂O₃, g in fig. 7 is a diagram showing the band structure of β - (Rh _0.4375Ga_0.5625)₂O₃, and h in fig. 7 is a diagram showing the band structure of β - (Rh _0.5Ga_0.5)₂O₃.

As shown in fig. 7, solid solution Rh can improve the beta-Ga ₂O₃ valence band top dispersion relationship. In the range 0 < x.ltoreq.0.25, β - (Rh _xGa_1-x)_2yO₃ is a direct bandgap semiconductor, the conduction band bottom and the valence band top are both at the center point of the Brillouin zone, the dispersion relationship of the valence band top becomes steeper as X increases analysis shows that the valence band top is contributed mainly by the density of states of Rh and adjacent O delocalized, rh starts to occupy adjacent octahedral center sites when X is greater than 0.25, the interaction of neighboring Rh changes the position and dispersion relationship of the top and bottom of the valence band beta- (Rh _0.3125Ga_0.6875)₂O₃ is still a direct bandgap semiconductor with the bottom of the conduction band and top of the valence band at the point, at X of 0.375 and 0.4375, the valence band top is shifted to the high symmetry N point in β - (Rh _0.5Ga_0.5)₂O₃) the valence band top is located between the high symmetry paths N-X.

Specifically, the application determines the valence band top position of beta- (Rh _xGa_1-x)_2yO₃) at different atomic percentages x based on the energy band structure of FIG. 7. Based on the valence band top position, the energy band dispersion relationship is drawn with a high density k point along the high symmetry direction, and the dispersion relationship near the valence band top is fitted with a second order polynomial function.

The calculation formula of the effective mass of the cavity is as follows:

Wherein, Is the dirac constant and is used to determine,Is the k point value of the Brillouin zone. After obtaining the hole mass of each high symmetry direction, the conductance average hole effective mass of the system is further calculated.

Fig. 8 shows the average hole effective mass of beta- (Rh _xGa_1-x)_2yO₃) provided in examples 1-8 as a whole, rh solutionizing increases the dispersion curvature of the valence band top, decreasing the hole effective mass, as shown in fig. 8. Specifically, when x=0.125, the hole effective mass of β - (Rh _xGa_1-x)_2yO₃) is about 4.2 m _e, when x=0.1875, the hole effective mass of β - (Rh _xGa_1-x)_2yO₃) is about 2.7 m _e, x=0.25, the hole effective mass of β - (Rh _xGa_1-x)_2yO₃ is about 2.2 m _e, x=0.3125, the hole effective mass of β - (Rh _xGa_1-x)_2yO₃ is about 6.4 m _e, x=0.375, the hole effective mass of beta- (Rh _xGa_1-x)_2yO₃) is about 3.04 m _e, x=0.4375, the hole effective mass of beta- (Rh _xGa_1-x)_2yO₃) is about 2.95 m _e, At x=0.5, the hole effective mass of β - (Rh _xGa_1-x)_2yO₃) is about 2.98 m _e. In particular, in the range of 0 < x.ltoreq.0.25, the average hole effective mass monotonically decreases with increasing x. The value of beta-Ga ₂O₃ is 4.24 m _e, while the value of beta- (Rh _0.25Ga_0.25)₂O₃) is only 2.22 m _e, 52.3% of the former. In the range of 0.375.ltoreq.x.ltoreq.0.5, the average effective mass of the holes of beta- (Rh _xGa_1-x)_2yO₃) is in the range of 2.95 m _e-3.04 m_e and still is significantly lower than the value of beta-Ga ₂O₃, which shows that the effective mass of the holes of beta- (Rh _xGa_1-x)_2yO₃) obtained by the application is smaller, the dispersion relation is steep, the phenomena of hole self-trapping and the like can be avoided, and p-type doping is facilitated.

When x is 0.0625, the hole effective mass of β - (Rh _0.0625Ga_0.9375)₂O₃) is not all given because the hole effective mass of β - (Rh _0.0625Ga_0.9375)₂O₃) is large.

Fig. 9 is an energy band alignment diagram of β - (Rh _xGa_1-x)_2yO₃) provided in examples 1-8, with upper conduction band, lower valence band, and intermediate value representing band gap values for β - (Rh _xGa_1-x)_2yO₃, rh and O electron orbitals form a solid solution valence band top, significantly higher than the 2p orbital level position of O, as shown in fig. 9, with the valence band top level position of β - (Rh _0.0625Ga_0.9375)₂O₃ raised by 1.81 eV compared to the valence band top of β -Ga ₂O₃,β-(Rh_xGa_1-x)_2yO₃, and further, with the valence band top of β - (Rh _xGa_1-x)_2yO₃ slowly increasing with an increase in Rh content, the valence band top of β - (Rh _0.5Ga_0.5)₂O₃ raised by 0.49 eV compared to the value of β - (Rh _0.0625Ga_0.9375)₂O₃.

It should be noted that, according to the common acceptor level position of β -Ga ₂O₃, p-type doping can be expected to be achieved when the rising value of the valence band top level of the β - (Rh _xGa_1-x)_2yO₃) semiconductor material is 1.1eV or more.

With continued reference to fig. 9, β - (Rh _xGa_1-x)_2yO₃) has a band gap value of 4.81 eV, x=0.0625, β - (Rh _xGa_1-x)_2yO₃) has a band gap value of 3.77 ev, x=0.125, x=0.1875, the band gap value of β - (Rh _xGa_1-x)_2yO₃ is 3.93 ev, the band gap value of β - (Rh _xGa_1-x)_2yO₃ is 4.04 ev, the band gap value of x=0.3125, the band gap value of β - (Rh _xGa_1-x)_2yO₃ is 4.10 eV, When x=0.375, the band gap value of β - (Rh _xGa_1-x)_2yO₃ is 3.95 ev, when x=0.4375, the band gap value of β - (Rh _xGa_1-x)_2yO₃ is 3.88 ev, and when x=0.5, the band gap value of β - (Rh _xGa_1-x)_2yO₃) is 3.93 eV. Beta- (Rh _xGa_1-x)_2yO₃) still has a wider band gap value due to the simultaneous rise of the conduction band bottom, belonging to a wide bandgap semiconductor, beta- (Rh _0.0625Ga_0.9375)₂O₃ has a minimum band gap value in the studied x range, and the value still reaches 3.77 eV, which is significantly higher than the band gap values of commercial SiC and GaN, which is also greater than the maximum band gap value reported in solid solutions of beta- (Bi _xGa_1-x)₂O₃) (3.60 eV). In the range of 0 < x.ltoreq.0.3125, the band gap of β - (Rh _xGa_1-x)_2yO₃ increases with increasing Rh content, where the value of β - (Rh _0.3125Ga_0.6875)₂O₃ reaches 4.10 eV the ultra wide band gap indicates that β - (Rh _xGa_1-x)_2yO₃) is applicable to high power semiconductor devices.

When x is more than or equal to 0.125 and less than or equal to 0.25 and y is more than or equal to 0.9 and less than or equal to 1.1 in the beta- (Rh _xGa_1-x)_2yO₃ semiconductor material system, and referring to fig. 8 and 9, when x=0.125, 0.1875 and 0.25, the effective hole masses of beta- (Rh _0.125Ga_0.875)₂O₃、β-(Rh_0.1825Ga_0.8125)₂O₃ and beta- (Rh _0.25Ga_0.75)₂O₃) are respectively 4.2 m _e、2.7 m_e and 2.2 m _e, and the band gap values are respectively 3.86 eV, 3.93 eV and 4.04 eV, that is, when x is more than or equal to 0.125 and less than or equal to 0.25 and y is more than or equal to 0.9 and less than or equal to 1.1, the beta- (Rh _xGa_1-x)_2yO₃ semiconductor material has lower effective hole masses and wider band gap values, and better comprehensive performance and is more favorable for p-type doping.

The grown beta- (Rh _xGa_1-x)_2yO₃ semiconductor layer has a proportion x of Rh atom number to Rh and Ga total atom number of 0-50 at%, and the Rh-containing gallium oxide semiconductor material has a beta-Ga ₂O₃ monoclinic structure, y is in the range of 0.9-1.1, and the crystal structure is characterized by XRD diffraction pattern, so that beta- (Rh _xGa_1-x)_2yO₃ has (-201) characteristic peaks similar to beta-Ga ₂O₃, and the peak position offset is about 0.5 degrees.

It should be noted that the novel semiconductor beta- (Rh _xGa_1-x)_2yO₃) system contains three elements of Rh, ga and O, has Rh-O and Ga-O chemical bonds, can also contain other elements, and when the novel semiconductor beta- (Rh _xGa_1-x)_2yO₃) system contains other elements, rh, ga and O are main element components, beta- (Rh _xGa_1-x)_2yO₃ has direct band gap semiconductor characteristics in a wide concentration range of 0 < x.ltoreq.0.3125 and 0.375 < x < 0.5, and band gap values are in the range of 3.77eV-4.10 eV, and can be applied to deep ultraviolet photoelectric devices, beta- (Rh _xGa_1-x)_2yO₃) has higher band top energy level and steep band top dispersion relation, so that p-type doping is conveniently realized.

All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application. Wherein, in the description of the embodiments of the present application, unless otherwise indicated, "/" means or, for example, a/B may represent a or B; the text "and/or" is merely an association relation describing the associated object, and indicates that three relations may exist, for example, a and/or B may indicate: the three cases where a exists alone, a and B exist together, and B exists alone, and furthermore, in the description of the embodiments of the present application, "plural" means two or more than two.

Wherein the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as implying or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature, and in the description of embodiments of the application, unless otherwise indicated, the meaning of "a plurality" is two or more.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

A semiconductor material, characterized in that the chemical formula of the semiconductor material is β-(Rh _x Ga _1-x ) _2y O ₃ , wherein 0.125≤x≤0.5, and 0.9≤y≤1.1.

2 . The semiconductor material according to claim 1 , wherein in the β-(Rh _x Ga _1-x ) _2y O ₃ , the range of x is 0.125≤x≤0.25, and the range of y is 0.9≤y≤1.1.

3. The semiconductor material according to claim 1, characterized in that the mixing enthalpy of the semiconductor material is 0 eV/cation-0.14 eV/cation.

4 . The semiconductor material according to claim 1 , wherein the effective mass of holes in the semiconductor material is 2 _me -7 _me .

5. The semiconductor material according to any one of claims 1 to 3, characterized in that the difference between the valence band top energy level of the semiconductor material and _that of β- _Ga2O3 is greater than or equal to 1.1 eV.

6. The semiconductor material according to any one of claims 1 to 3, characterized in that the energy band gap value of the semiconductor material is 3.77 eV-4.10 eV.

7. A semiconductor device, comprising a substrate and a semiconductor layer, wherein the semiconductor layer is made of the semiconductor material according to any one of claims 1 to 6.

8 . The semiconductor device according to claim 7 , wherein the semiconductor layer is a p-type semiconductor layer or an n-type semiconductor layer.

9 . The semiconductor device according to claim 7 , wherein the crystal orientation of the substrate is [010] orientation.

10. A method for preparing a semiconductor device, comprising:

Substrate preheating: Place the β-Ga ₂ O ₃ substrate in the growth chamber and preheat it;

Growth: introducing source materials including an O source, a Ga source and a Rh source into the growth chamber, and growing a β-( _RhxGa1 _-x ₎ _2yO3 semiconductor layer on _the β- _Ga2O3 substrate through reaction, wherein 0.125≤x≤0.5, and 0.9≤y≤1.1.

The preparation method according to claim 10, characterized in that the crystal orientation of the β-Ga ₂ O ₃ substrate is [010] crystal orientation.

12. The preparation method according to claim 10, characterized in that the temperature of the Ga source introduced is 800°C-900°C, and the temperature of the Rh source introduced is ≥1500°C.

13. The preparation method according to claim 10, characterized in that the growth temperature of _the β-( _RhxGa1 _-x ) _2yO3 is 600°C-800°C.