Preparation method, detection method and application of Fe and Ni co-doped GaSb single crystal film

Abstract

The invention provides a preparation method, a detection method and application of a Fe and Ni co-doped GaSb single crystal film. The preparation method comprises the following steps: S1, epitaxially forming a GaAs buffer layer (2) on a deoxidized semi-insulating GaAs substrate (1) by adopting a molecular beam epitaxy technology; s2, extending an AlSb seed layer (3) on the GaAs buffer layer (2) at a first growth temperature; s3, extending a layer of (Al, Ga) Sb isolation layer (4) with gradually changed components on the AlSb seed layer (3); s4, at a second growth temperature, epitaxially forming a layer of Fe and Ni co-doped GaSb film (5) on the (Al, Ga) Sb isolation layer (4) by adopting a low-temperature molecular beam epitaxy technology; and S5, depositing a GaSb cover layer (6) on the Fe and Ni co-doped GaSb thin film (5) to obtain the antimonide magnetic semiconductor Ga1-x-yFexNiySb single crystal thin film. The Ga < 1-x-y > Fe < x > Ni < y > Sb single crystal thin film obtained by the invention has the advantages of room-temperature ferromagnetism, relatively strong magnetic anisotropy, relatively high hole mobility, large-range adjustability of carrier concentration and the like.

Description

Technical Field

[0001] The present disclosure relates to the technical field of condensed matter physics topological materials, and in particular to a preparation method, a detection method and an application of a Fe and Ni co-doped GaSb single crystal film. Background Art

[0002] Spin electronics has emerged as a result of the growing demand for computing power in the semiconductor industry and the contradiction between the fluctuations in performance parameters of traditional electronic devices as the size of the devices continues to shrink to the nanoscale. Spin electronics studies how to simultaneously manipulate the charge and spin freedom of electrons. Semiconductor spin electronics is an important branch of this field, which studies how to simultaneously manipulate the charge and spin of electrons in semiconductor material systems. For the development of semiconductor spin electronics, the development of new materials is crucial. Among many materials, magnetic semiconductors have attracted widespread attention and have been studied in depth. Magnetic semiconductors combine the dual characteristics of ferromagnets and semiconductors and are regarded as the basic materials for the next generation of semiconductor devices. Practical applications require that magnetic semiconductors have the following advantages: the Curie temperature is higher than room temperature; the carrier conductivity type can be both n-type and p-type, which is convenient for making pn junctions; the magnetic anisotropy can be changed over a wide range, etc. In the past few decades, research on magnetic semiconductors has mainly focused on breaking through the solid solubility limit and then incorporating a large amount of magnetic elements into semiconductors. Typical magnetic semiconductors obtained include Mn-based III-V magnetic semiconductors such as p-type (Ga, Mn) As and p-type (In, Mn) As. Mn-based III-V magnetic semiconductors still have many disadvantages, such as single conductivity type (only p-type), maximum Curie temperature does not exceed room temperature ((Ga,Mn)As Curie temperature 200K, (In,Mn)As maximum Curie temperature 90K), etc. New progress has been made in the Curie temperature of Fe-based III-V antimonide magnetic semiconductors, with maximum Curie temperatures of 385K in n-type (In,Fe)Sb and 400K in p-type (Ga,Fe)Sb. However, taking (Ga,Fe)Sb as an example, it still has many problems to be solved, such as too weak magnetic anisotropy. When the Fe concentration is 30%, its magnetic anisotropy constant is only 7.6×10 3 erg / cm 3 , about one order of magnitude lower than (Ga,Mn)As. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In response to the above problems, the present disclosure provides a preparation method, detection method and application of Fe and Ni co-doped GaSb single crystal film, which is used to at least partially solve the technical problems of traditional magnetic semiconductor materials such as single conductivity type, maximum Curie temperature not exceeding room temperature, and too weak magnetic anisotropy.

[0005] (II) Technical solution

[0006] On the one hand, the present disclosure provides a method for preparing a Fe-Ni co-doped GaSb single crystal film, comprising: S1, epitaxially growing a GaAs buffer layer on a deoxidized semi-insulating GaAs substrate using a molecular beam epitaxy technique; S2, epitaxially growing an AlSb seed layer on the GaAs buffer layer at a first growth temperature; S3, epitaxially growing a composition-gradient (Al, Ga) Sb insulating layer on the AlSb seed layer; S4, epitaxially growing a Fe-Ni co-doped GaSb film on the (Al, Ga) Sb insulating layer at a second growth temperature using a low-temperature molecular beam epitaxy technique; S5, depositing a GaSb cap layer on the Fe-Ni co-doped GaSb film to obtain an antimonide magnetic semiconductor GaSb. 1-x-y Fe x Ni y Sb single crystal thin film.

[0007] According to the embodiments of the present disclosure, the thickness of the epitaxial GaAs buffer layer in S1 is in the range of 100 to 500 nm; the temperature of the epitaxial GaAs buffer layer is in the range of 540°C to 560°C; and the equivalent beam pressure ratio of Ga and As during the epitaxial process is in the range of 1:(8 to 10).

[0008] According to the embodiments of the present disclosure, the thickness of the epitaxial AlSb seed layer in S2 is in the range of 3nm to 6nm; the equivalent beam pressure ratio of Al and Sb during the epitaxial process is in the range of 1:(6-7); and the first growth temperature is in the range of 470°C to 490°C.

[0009] According to the embodiments of the present disclosure, the thickness range of the epitaxial (Al, Ga)Sb isolation layer in S3 is greater than 250 nm; during the epitaxial process, the equivalent beam pressure ratio of Al, Ga, and Sb gradually changes from (7-8.5):(1-1.5):(65-80) to (9-11):(1-1.5):(75-90), the proportion of the Al component gradually increases, and the proportion of the Ga component gradually decreases.

[0010] According to the embodiments of the present disclosure, the thickness of a Fe and Ni co-doped GaSb film epitaxially grown in S4 is in the range of 100 nm to 120 nm; the second growth temperature is in the range of 250°C to 300°C; and the equivalent beam pressure ratio of Ga, Fe, Ni, and Sb during the epitaxial process is in the range of (65 to 75):(23 to 24):(1 to 7):(580 to 620).

[0011] According to an embodiment of the present disclosure, the thickness range of a GaSb cap layer deposited in S5 is 1 nm to 2 nm; the temperature range of depositing a GaSb cap layer is 250° C. to 300° C.; the equivalent beam pressure ratio of Ga and Sb during the deposition process is in the range of (7 to 8): (60 to 62).

[0012] Another aspect of the present disclosure provides a GaSb single crystal film obtained by the method for preparing the Fe and Ni co-doped GaSb single crystal film. 1-x-y Fe x Ni y The detection method of Sb single crystal thin film includes: using a comprehensive physical property measurement system to characterize Ga 1-x-y Fe x Ni y Electrical transport properties of Sb single crystal thin films; and characterization of Ga using superconducting quantum interference device magnetometer 1-x-y Fe x Ni y Magnetic properties of Sb single crystal thin films.

[0013] According to an embodiment of the present disclosure, a comprehensive physical property measurement system is used to characterize Ga 1-x-y Fe x Ni y The electrical transport properties of Sb single crystal thin films include: Ga 1-x-y Fe x Ni y The Hall bar device of Sb single crystal film uses a comprehensive physical property measurement system to measure the magnetic field dependence characteristics of the Hall resistance of samples with different Fe and Ni doping concentrations at different temperatures; the hole mobility is calculated based on the test data of samples with different Fe and Ni doping concentrations at low temperature and high field using a comprehensive physical property measurement system.

[0014] According to an embodiment of the present disclosure, a superconducting quantum interference device magnetometer is used to characterize Ga 1-x-y Fe x Ni y The magnetic properties of Sb single crystal films include: using a superconducting quantum interference device magnetometer, under the condition of applying magnetic fields in different directions, testing the curves of magnetization intensity of samples with different Fe and Ni doping concentrations as a function of magnetic field strength; where magnetic fields in different directions include magnetic fields in the plane and perpendicular to the plane.

[0015] In another aspect, the present disclosure provides a method for preparing a GaSb single crystal thin film co-doped with Fe and Ni. 1-x-y Fe x Ni y The purpose of Sb single crystal thin film is to prepare all-electrically controlled field effect transistors.

[0016] (III) Beneficial effects

[0017] The preparation method, detection method and application of Fe and Ni co-doped GaSb single crystal thin film provided in the present invention adopt molecular beam epitaxy technology to establish a new method for synthesizing Fe and Ni co-doped GaSb single crystal thin film; the obtained antimonide magnetic semiconductor Ga 1-x-y Fe x Ni y Sb thin film has the advantages of room temperature ferromagnetism, strong magnetic anisotropy, high hole mobility and wide range of adjustable carrier concentration, and has the potential to be used in the production of fully electrically controlled field effect transistors. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The schematic diagram shows a process diagram of a method for preparing a Fe and Ni co-doped GaSb single crystal thin film according to an embodiment of the present disclosure;

[0019] Figure 2 The schematic diagram shows the antimonide magnetic semiconductor Ga according to the embodiment of the present disclosure. 1-x-y Fe x Ni y Schematic diagram of the structure of Sb single crystal thin film;

[0020] Figure 3 Schematic diagram of Ga with different Fe and Ni doping concentrations according to the embodiment of the present disclosure 1-x- y x Ni y Schematic diagram of the magnetic field dependence of the Hall resistance of Sb single crystal thin film at 10K;

[0021] Figure 4 A schematic diagram of a curve showing a change in magnetization intensity of a Ga1-x-yFexNiySb single crystal film with different Fe and Ni doping concentrations under an applied in-plane and perpendicular magnetic field as a function of magnetic field intensity according to an embodiment of the present disclosure is shown;

[0022] Description of reference numerals:

[0023] 1. Semi-insulating GaAs substrate; 2. GaAs buffer layer; 3. AlSb seed layer; 4. (Al, Ga)Sb insulation layer; 5. Fe and Ni co-doped GaSb film; 6. GaSb cap layer. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0025] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0026] Various directional words in the present disclosure, such as "front", "back", "left", "right", "up", "down", etc., are only for the convenience of description and are used to describe the relative position relationship between the various components, rather than to limit the present disclosure. Different product placement methods of the present disclosure may result in changes in the various directional descriptions.

[0027] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean or represent any ordinal number of the element, nor do they represent the order of one element and another element, or the order of manufacturing methods. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0028] In order to solve the problem of too weak magnetic anisotropy that still exists in (Ga,Fe)Sb, the present invention adopts a new method for growing Fe and Ni co-doped antimonide magnetic semiconductors and provides a growth process of Fe and Ni co-doped antimonide magnetic semiconductors.

[0029] The present disclosure provides a method for preparing Fe and Ni co-doped GaSb single crystal thin film, see Figure 1-2 , including: S1, epitaxially growing a GaAs buffer layer on a deoxidized semi-insulating GaAs substrate using a molecular beam epitaxy technique; S2, epitaxially growing an AlSb seed layer on the GaAs buffer layer at a first growth temperature; S3, epitaxially growing a compositionally graded (Al, Ga)Sb insulating layer on the AlSb seed layer; S4, epitaxially growing a Fe, Ni co-doped GaSb thin film on the (Al, Ga)Sb insulating layer at a second growth temperature using a low-temperature molecular beam epitaxy technique; S5, depositing a GaSb cap layer on the Fe, Ni co-doped GaSb thin film to obtain an antimonide magnetic semiconductor GaSb. 1-x-y Fe x Ni y Sb single crystal thin film.

[0030] The method uses low-temperature non-equilibrium molecular beam epitaxy technology, combined with magnetic element co-doping and component modulation of multiple buffer layers to gradually transition to release stress, to prepare Fe and Ni co-doped GaSb single crystal films. Specifically, a GaAs buffer layer 2 for smoothing the substrate surface is epitaxially grown on a semi-insulating GaAs (001) substrate that has been pretreated and deoxidized at high temperature; the growth temperature is adjusted to epitaxially grow a thin layer of AlSb as a seed layer on the GaAs buffer layer 2, and a thick (Al, Ga) Sb insulating layer 4 with a gradient composition is epitaxially grown on the AlSb seed layer 3; the growth temperature is adjusted to epitaxially grow a Fe and Ni co-doped GaSb film 5 on the (Al, Ga) Sb insulating layer 4, and a GaSb film is deposited on the surface of the Fe and Ni co-doped GaSb single crystal film to prevent oxidation of the magnetic layer. The antimonide magnetic semiconductor GaSb thus obtained 1-x-y Fe x Ni y Sb thin films have the advantages of room temperature ferromagnetism, strong magnetic anisotropy, high hole mobility and adjustable carrier concentration over a wide range.

[0031] Based on the above embodiment, the thickness of the epitaxial GaAs buffer layer 2 in S1 is in the range of 100 to 500 nm; the temperature range of the epitaxial GaAs buffer layer 2 is 540°C to 560°C; and the equivalent beam pressure ratio of Ga and As during the epitaxial process is in the range of 1:(8 to 10).

[0032] The GaAs buffer layer 2 for smoothing the substrate surface is grown epitaxially on the semi-insulating GaAs (001) substrate after pretreatment and high-temperature deoxidation, and the GaAs buffer layer 2 is grown epitaxially on the semi-insulating GaAs (001) substrate using molecular beam epitaxy technology. The thickness of the GaAs buffer layer 2 within the above range is conducive to suppressing dislocations and stacking faults and improving surface flatness; the temperature within the above range is to approach the optimal growth temperature of GaAs, which is conducive to improving crystal quality; the equivalent beam pressure ratio of Ga and As within the above range is conducive to presenting a 2×4 surface reconstruction on the GaAs surface, which is conducive to the subsequent epitaxial growth of multilayer films.

[0033] Preferably, the thickness of the GaAs buffer layer 2 is 250 nm, the equivalent beam pressure ratio of Ga to As is about 2:19, and the growth temperature is about 550°C.

[0034] Based on the above embodiment, the thickness of the epitaxial AlSb seed layer 3 in S2 is in the range of 3nm to 6nm; the equivalent beam pressure ratio of Al and Sb during the epitaxial process is in the range of 1:(6-7); and the first growth temperature is in the range of 470°C to 490°C.

[0035] The growth temperature is adjusted, and a thin layer of AlSb is epitaxially grown on the GaAs buffer layer 2 as a seed layer. The AlSb seed layer 3 is epitaxially grown on the GaAs buffer layer 3 using molecular beam epitaxy technology. The temperature of the epitaxial AlSb seed layer 3 is lower than the temperature of the epitaxial GaAs buffer layer 2. This is because the optimal growth temperature of AlSb is lower than that of GaAs. The thickness of the AlSb seed layer 3 cannot be too thick, otherwise the interface quality will be reduced. The equivalent beam pressure ratio of Al and Sb within the above range is beneficial to improving the quality of the AlSb crystal.

[0036] Preferably, the thickness of the AlSb seed layer 3 is 3 nm, the equivalent beam pressure ratio of Al to Sb is about 2:13, and the growth temperature is about 470°C.

[0037] On the basis of the above-mentioned embodiment, the thickness range of the epitaxial (Al, Ga)Sb insulation layer 4 in S3 is greater than 250nm; during the epitaxial process, the equivalent beam pressure ratio of Al, Ga, and Sb gradually changes from (7-8.5): (1-1.5): (65-80) to (9-11): (1-1.5): (75-90), the proportion of Al component gradually increases, and the proportion of Ga component gradually decreases.

[0038] A thick (Al, Ga)Sb insulating layer 4 with a gradient composition is epitaxially grown on the AlSb seed layer 3. The (Al, Ga)Sb insulating layer 4 is epitaxially grown on the AlSb seed layer 3 using molecular beam epitaxy technology. The thickness range of the (Al, Ga)Sb insulating layer 4 is greater than 250nm, which is beneficial to suppressing dislocations and stacking faults, improving surface flatness, and providing room for the realization of gradient composition. The gradient composition of the (Al, Ga)Sb insulating layer 4 is to reduce the strain caused by lattice mismatch, thereby reducing dislocations and stacking faults, and further improving crystal quality and surface flatness.

[0039] Preferably, the total thickness of the (Al, Ga) Sb insulating layer 4 is 500 nm, the equivalent beam pressure ratio of Al, Ga, and Sb gradually changes from about 8:1:72 to about 9:1:80, and the thickness of the (Al, Ga) Sb insulating layer 4 is 350 nm. The composition of the (Al, Ga) Sb insulating layer 4 is, for example, Al 0.9 Ga 0.1 Sb.

[0040] On the basis of the above embodiments, the thickness of a Fe and Ni co-doped GaSb film epitaxially grown in S4 is in the range of 100nm to 120nm; the second growth temperature is in the range of 250°C to 300°C; and the equivalent beam pressure ratio of Ga, Fe, Ni, and Sb during the epitaxial process is in the range of (65 to 75):(23 to 24):(1 to 7):(580 to 620).

[0041] The growth temperature is adjusted, and the Fe and Ni co-doped GaSb film 5 is epitaxially grown on the (Al, Ga) Sb insulating layer 4, and the Fe and Ni co-doped GaSb film 5 is grown on the (Al, Ga) Sb insulating layer 4 using low-temperature molecular beam epitaxy technology. The growth temperature of the Fe and Ni co-doped GaSb film 5 is lower, because the epitaxial growth of the magnetic semiconductor (Ga, Fe, Ni) Sb can be achieved by using the non-equilibrium growth process of low-temperature molecular beam epitaxy; the thickness of the Fe and Ni co-doped GaSb film 5 within the above range is conducive to improving the magnetic anisotropy of the magnetic layer, and can also improve the conductivity and thus facilitate the Hall resistance measurement at low temperature; the equivalent beam pressure ratio of Ga, Fe, Ni, and Sb within the above range is conducive to obtaining a Curie temperature higher than room temperature, and the regulating effect of Ni doping on magnetic anisotropy and hole mobility can be clearly observed, and better crystal quality can be obtained within this range.

[0042] Preferably, the thickness of the Fe and Ni co-doped GaSb film 5 is 100 nm, the equivalent beam pressure ratio of Ga, Fe, Ni and Sb is from about 75:24:1:600 ​​to about 69:24:7:600, and the growth temperature is 300°C.

[0043] Based on the above embodiment, the thickness range of the GaSb cap layer 6 deposited in S5 is 1nm~2nm; the temperature range of depositing the GaSb cap layer 6 is 250℃~300℃; the equivalent beam pressure ratio of Ga and Sb during the deposition process is in the range of (7~8):(60~62).

[0044] A GaSb capping layer 6 is deposited on the surface of the Fe and Ni co-doped GaSb film 5 to prevent oxidation of the magnetic layer. The GaSb capping layer 6 is deposited on the surface of the Fe and Ni co-doped GaSb film 5 using molecular beam epitaxy technology. The temperature for depositing the GaSb capping layer 6 is the same as the temperature used in growing the Fe and Ni co-doped GaSb film 5, so as to avoid high temperature from damaging the structure of the (Ga, Fe, Ni)Sb layer and to avoid crystal quality fluctuations caused by temperature changes in the process. The equivalent beam pressure ratio of Ga and Sb is the same as the equivalent beam pressure ratio of Ga and Sb used in growing the Fe and Ni co-doped GaSb film 5. After the (Ga, Fe, Ni)Sb layer is grown, the Fe and Ni source furnace baffles are directly closed to grow the GaSb capping layer 6. This is to quickly form an anti-oxidation film on the surface to avoid crystal quality fluctuations that may be caused by changing the beam ratio.

[0045] Preferably, the thickness of the GaSb cap layer 6 is 2 nm, the equivalent beam pressure ratio of Ga to Sb is about 1:8, and the growth temperature is about 300°C.

[0046] The present disclosure adopts molecular beam epitaxy technology to epitaxially grow a GaAs buffer layer 2 for smoothing the substrate surface on a deoxidized semi-insulating GaAs substrate 1; adjust the growth temperature to epitaxially grow an AlSb insulating layer as a seed layer on the GaAs buffer layer 2, and epitaxially grow a (Al, Ga) Sb insulating layer 4 with a gradient composition on the AlSb seed layer 3; adjust the growth temperature to epitaxially grow a Fe and Ni co-doped GaSb film 5 on the (Al, Ga) Sb insulating layer 4, and deposit a GaSb cap layer 6 on the surface of the Fe and Ni co-doped GaSb film 5 to prevent oxidation of the magnetic layer. The present disclosure identifies a method for growing high-quality single crystal thin films of antimonide magnetic semiconductors co-doped with dual magnetic elements and having room temperature ferromagnetism. Compared with (Ga, Fe) Sb magnetic semiconductors, GaSb has a higher density than Ni co-doped GaSb films. 1-x-y Fe x Ni y The magnetic anisotropy and hole mobility of Sb are significantly improved.

[0047] The present disclosure also provides a GaSb single crystal film obtained by the preparation method of the Fe and Ni co-doped GaSb single crystal film. 1-x-y Fe x Ni y The detection method of Sb single crystal thin film includes: using a comprehensive physical property measurement system to characterize Ga 1-x-y Fe x Ni y Electrical transport properties of Sb single crystal thin films; and characterization of Ga using superconducting quantum interference device magnetometer 1-x-y Fe x Ni y Magnetic properties of Sb single crystal thin films.

[0048] The present disclosure involves growing a magnetic element co-doped multilayer film with GaSb as the main component by a low-temperature non-equilibrium molecular beam epitaxy method and using a multi-buffer layer gradual transition method. In addition, a superconducting quantum interference device magnetometer and anomalous Hall effect are comprehensively used to characterize the macroscopic and microscopic magnetic properties of the material.

[0049] Based on the above examples, the comprehensive physical property measurement system is used to characterize Ga 1-x-y Fe x Ni y The electrical transport properties of Sb single crystal thin films include: Ga 1-x-y Fe x Ni y The Hall bar device of Sb single crystal film uses a comprehensive physical property measurement system to measure the magnetic field dependence characteristics of the Hall resistance of samples with different Fe and Ni doping concentrations at different temperatures; the hole mobility is calculated based on the test data of samples with different Fe and Ni doping concentrations at low temperature and high field using a comprehensive physical property measurement system.

[0050] Based on the above embodiment, the superconducting quantum interference device magnetometer is used to characterize Ga 1-x-y Fe x Ni y The magnetic properties of Sb single crystal films include: using a superconducting quantum interference device magnetometer, under the condition of applying magnetic fields in different directions, testing the curves of magnetization intensity of samples with different Fe and Ni doping concentrations as a function of magnetic field strength; where magnetic fields in different directions include magnetic fields in the plane and perpendicular to the plane.

[0051] The present disclosure also provides a method for preparing the Fe and Ni co-doped GaSb single crystal film to obtain GaSb 1-x-y Fe x Ni y The purpose of Sb single crystal thin film is to prepare all-electrically controlled field effect transistors.

[0052] The Ga obtained in this disclosure 1-x-y Fe x Ni y Sb single crystal film has the advantages of room temperature ferromagnetism, strong magnetic anisotropy, high hole mobility and wide range of adjustable carrier concentration, and has the potential to be used in the production of fully electrically controlled field effect transistors.

[0053] The present disclosure is further described below through specific implementation methods. The preparation method, detection method and application of the above-mentioned Fe and Ni co-doped GaSb single crystal thin film are specifically described in the following examples. However, the following examples are only used to illustrate the present disclosure, and the scope of the present disclosure is not limited thereto.

[0054] This embodiment provides a method for obtaining room temperature strong magnetic anisotropy antimonide magnetic semiconductors. The method uses molecular beam epitaxy technology to establish a new method for synthesizing Fe and Ni co-doped GaSb single crystal thin films and obtain high-quality ferromagnetic Ga l-x-y Fe x Ni y Sb single crystal thin film.

[0055] Figure 1 This embodiment provides the ferromagnetic Ga 1-x-y Fe x Ni y Sb single crystal thin film method flow chart, the method comprises the following steps:

[0056] Step 1: epitaxially growing a GaAs buffer layer 2 for smoothing the surface of the substrate on a deoxidized semi-insulating GaAs substrate 1; equivalent to the above-mentioned step S1.

[0057] Step 2: adjusting the growth temperature and epitaxially growing an AlSb insulating layer as a seed layer on the GaAs buffer layer 2; equivalent to the above step S2.

[0058] Step 3: epitaxially grow an (Al, Ga)Sb insulating layer 4 on the AlSb seed layer 3; equivalent to the above step S3.

[0059] Step 4: adjusting the growth temperature, and epitaxially growing the Fe and Ni co-doped GaSb thin film 5 on the (Al, Ga)Sb insulating layer 4; equivalent to the above step S4.

[0060] Step 5: depositing a GaSb capping layer 6 on the surface of the Fe and Ni co-doped GaSb film 5 to prevent the Fe and Ni co-doped GaSb film 5 from being oxidized; equivalent to the above step S5.

[0061] The following is a 100 nm Ga synthesized by the growth method in this embodiment. 1-x-y Fe x Ni y Taking Sb single crystal thin film as an example, this embodiment is further described in detail in conjunction with the accompanying drawings.

[0062] Sample structure see Figure 2 In this embodiment, a GaAs buffer layer 2 with a thickness of about 100 nm is first grown on a semi-insulating GaAs substrate 1 after degassing and deoxidation, and the growth temperature is about 550°C. Afterwards, the growth temperature is lowered to about 470°C to grow an AlSb seed layer 3 with a thickness of about 3 nm. Then, an (Al, Ga) Sb insulating layer 4 with a total thickness of about 500 nm is grown at 540°C. Then, a Fe and Ni co-doped GaSb film 5 with a thickness of about 100 nm is epitaxially grown on the (Al, Ga) Sb insulating layer 4. Finally, a GaSb cap layer 6 with a thickness of about 2 nm is deposited to protect the sample from oxidation of the (Ga, Fe, Ni) Sb single crystal film.

[0063] Figure 3 The Ga with different Fe and Ni doping concentrations (x≈24%, y=1.7%-6.1%) is given. 1-x-y Fe x Ni y Magnetic field dependence of the Hall resistance of Sb single crystal film at 10K. The inset is the test data near zero field, showing a typical hysteresis loop. The dashed line is the linear fit of the high field data. According to ΔR xy / ΔB calculated mobility. The sample mobility is as high as 31.3cm when y=1.7%. 2 / Vs, which is about 5 times that of (Ga,Fe)Sb when the Fe concentration is 25%. In addition, when the total doping concentration of magnetic elements is the same (x+y=x (Ga,Fe)Sb ), Ga 1-x-y Fe xNi y The mobility of Sb is generally about 5 times that of (Ga,Fe)Sb.

[0064] Figure 4 The Ga with different Fe and Ni doping concentrations is given. 1-x-y Fe x Ni y The variation curve of the magnetization intensity of Sb single crystal film with magnetic field strength under the magnetic field perpendicular to the sample direction (solid line plus solid triangle) and in-plane direction (dashed line plus hollow square). The magnetic field strength corresponding to each saturation magnetization intensity is Figure 4 The solid and dotted arrows are used to mark the sample. For the sample with y = 1.7%, the in-plane magnetization and perpendicular magnetization characteristic curves are similar, indicating that the magnetic anisotropy of the sample is small. For the sample with y = 2.8-6.1%, the in-plane and perpendicular magnetization curves are significantly different, and the saturation magnetization intensity M S The magnetic anisotropy constant increases with the increase of y. When y=6.1%, it reaches 3.8×10 5 erg / cm 3 , two orders of magnitude higher than (Ga,Fe)Sb.

[0065] So far, the present embodiment has been described in detail in conjunction with the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the sample structure, electrical and magnetic characterization processes in the present invention.

[0066] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for preparing a Fe and Ni co-doped GaSb single crystal thin film, characterized in that: include: S1, epitaxially growing a GaAs buffer layer (2) on a deoxidized semi-insulating GaAs substrate (1) using a molecular beam epitaxy technique; S2, epitaxially growing an AlSb seed layer (3) on the GaAs buffer layer (2) at a first growth temperature; S3, epitaxially growing a compositionally graded (Al, Ga)Sb isolation layer (4) on the AlSb seed layer (3); S4, at a second growth temperature, epitaxially growing a Fe and Ni co-doped GaSb thin film (5) on the (Al, Ga)Sb insulating layer (4) using a low-temperature molecular beam epitaxy technique; S5, depositing a GaSb cap layer (6) on the Fe and Ni co-doped GaSb film (5) to obtain an antimonide magnetic semiconductor GaSb. 1-x-y Fe x Ni y Sb single crystal thin film.

2. The method for preparing the Fe and Ni co-doped GaSb single crystal thin film according to claim 1, characterized in that: The thickness of the epitaxial GaAs buffer layer (2) in S1 is in the range of 100 to 500 nm; The temperature range of epitaxially growing a GaAs buffer layer (2) is 540° C. to 560° C.; The equivalent beam pressure ratio of Ga and As during the epitaxial growth process ranges from 1:(8 to 10).

3. The method for preparing the Fe and Ni co-doped GaSb single crystal thin film according to claim 1, characterized in that: The thickness of the epitaxial AlSb seed layer (3) in S2 is in the range of 3 nm to 6 nm; The equivalent beam pressure ratio of Al and Sb during epitaxy is in the range of 1:(6-7); The first growth temperature ranges from 470°C to 490°C.

4. The method for preparing the Fe and Ni co-doped GaSb single crystal thin film according to claim 1, characterized in that: The thickness of the epitaxial (Al, Ga)Sb insulating layer (4) in S3 is greater than 250 nm; During the epitaxial growth process, the equivalent beam pressure ratio of Al, Ga, and Sb gradually changed from (7-8.5):(1-1.5):(65-80) to (9-11):(1-1.5):(75-90), the proportion of Al component gradually increased, and the proportion of Ga component gradually decreased.

5. The method for preparing the Fe and Ni co-doped GaSb single crystal thin film according to claim 1, characterized in that: The thickness of the Fe and Ni co-doped GaSb thin film (5) epitaxially grown in S4 is in the range of 100 nm to 120 nm; The second growth temperature ranges from 250°C to 300°C; The equivalent beam pressure ratio of Ga, Fe, Ni and Sb in the epitaxial process ranges from (65 to 75): (23 to 24): (1 to 7): (580 to 620).

6. The method for preparing the Fe and Ni co-doped GaSb single crystal thin film according to claim 1, characterized in that: The thickness of the GaSb cap layer (6) deposited in S5 is in the range of 1 nm to 2 nm; The temperature range for depositing a GaSb cap layer (6) is 250° C. to 300° C.; The equivalent beam pressure ratio of Ga and Sb during the deposition process ranges from (7 to 8) to (60 to 62).

7. A GaSb single crystal thin film obtained by the method for preparing a Fe and Ni co-doped GaSb single crystal thin film according to any one of claims 1 to 6 1-x-y Fe x Ni y The detection method of Sb single crystal thin film is characterized by: include: Characterization of Ga using a comprehensive physical property measurement system 1-x-y Fe x Ni y Electrical transport properties of Sb single crystal thin films; and The Ga 1-x-y Fe x Ni y Magnetic properties of Sb single crystal thin films.

8. Ga according to claim 7 1-x-y Fe x Ni y The detection method of Sb single crystal thin film is characterized by: The comprehensive physical property measurement system is used to characterize Ga 1-x-y Fe x Ni y The electrical transport properties of Sb single crystal thin films include: Fabrication of Ga by photolithography and ion beam etching 1-x-y Fe x Ni y The Hallbar device of Sb single crystal thin film uses a comprehensive physical property measurement system to measure the magnetic field dependence of the Hall resistance of samples with different Fe and Ni doping concentrations at different temperatures; The hole mobility is calculated using the test data of the samples with different Fe and Ni doping concentrations under low temperature and high field using a comprehensive physical property measurement system.

9. Ga according to claim 7 1-x-y Fe x Ni y The detection method of Sb single crystal thin film is characterized by: The method uses a superconducting quantum interference device magnetometer to characterize the Ga 1-x-y Fe x Ni y The magnetic properties of Sb single crystal thin films include: Using a superconducting quantum interference device magnetometer, under the condition of applying magnetic fields in different directions, the curves of magnetization intensity of samples with different Fe and Ni doping concentrations as a function of magnetic field strength are tested; wherein the magnetic fields in different directions include magnetic fields in the plane and perpendicular to the plane.

10. A method for preparing a Fe and Ni co-doped GaSb single crystal thin film according to any one of claims 1 to 6 to obtain Ga 1-x-y Fe x Ni y The purpose of Sb single crystal thin film is to prepare all-electrically controlled field effect transistors.

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