A ferromagnetic insulating SrFeO 2.0 Thin film transfer methods and applications on Si substrates

Abstract

This invention discloses a ferromagnetic insulating SrFeO 2.0 The method and application of thin film transfer on Si substrates, involving the field of materials technology applications, includes the following steps: on YAlO₂... 3 Sr fabrication on single crystal substrate 3 Al 2 O 6 The thin film serves as a sacrificial layer; in Sr 3 Al 2 O 6 / YAlO 3 Surface preparation of SrFeO in heterojunctions 2.0 Thin film, SrFeO 2.0 The film thickness is 2-50 nm; SrFeO 2.0 / Sr 3 Al 2 O 6 / YAlO 3 Polymer sheets are adhered to the heterojunction and placed in a deionized aqueous solution; SrFeO is then added. 2.0 A Si-based semiconductor substrate is adhered to a polymer sheet heterojunction and placed in an acetone solution to obtain SrFeO. 2.0 / Si heterojunction. This invention achieves SrFeO by introducing a water-soluble sacrificial layer. 2.0 The film is peeled off from the original rigid substrate and transferred to other flexible or Si substrates.

Description

A ferromagnetic insulating SrFeO 2.0 Thin film transfer methods and applications on Si substrates Technical Field

[0001] This invention relates to the field of materials technology applications, and more particularly to a ferromagnetic insulating SrFeO 2.0 Methods and applications for transferring thin films on Si substrates. Background Technology

[0002] Current highly integrated information technology places new demands on electronic materials / devices in terms of efficiency and energy consumption. Traditional electronic devices primarily process information using electron charge as the degree of freedom. Recently, electronic materials possessing both ferromagnetic and insulating properties, when used as tunneling layers in magnetic memories, can simultaneously store and process information using both electron charge and spin as carriers. This is beneficial for the further development of electronic information technology and is also a necessary condition for developing next-generation low-dissipation quantum spintronic devices. However, to date, there are few reports on the types of such electronic materials possessing both ferromagnetic and electrical insulating properties, and explorations into their flexibility and semiconductor-based integration are even rarer.

[0003] Currently, most electronic devices are integrated on Si-based semiconductors. However, semiconductors and metal oxides have poor compatibility, and with current thin-film material growth methods, it is difficult to deposit metal oxides on semiconductors, keeping the excellent properties of many oxides at the theoretical research stage. The technical problem this invention aims to solve is the lack of high-temperature ferromagnetic insulating materials and the difficulty in device fabrication mentioned in the background art. It introduces a sacrificial layer to provide a method for achieving high-temperature ferromagnetic insulation of SrFeO. 2.0 The method for separating and transferring thin films is simple, economical, reliable, and virtually environmentally friendly. When high-temperature ferromagnetic materials are used as tunneling layers, their thickness is required to improve storage efficiency; therefore, this invention addresses the issue of SrFeO... 2.0 A series of investigations were conducted on the thickness of the thin film. Summary of the Invention

[0004] This invention obtains SrFeO through large interfacial strain (on a YAlO3 single crystal substrate). 2.0 A novel structural phase thin film was achieved by introducing a water-soluble sacrificial layer to realize SrFeO 2.0 Separating the thin film from the original rigid substrate while maintaining the new phase structure, and transferring it to other flexible or Si substrates, provides material support and technological foundation for the development of high-temperature, low-dissipation quantum ferromagnetic insulated spin-integrated electronic devices.

[0005] To address the above problems, the present invention proposes the following technical solution:

[0006] Firstly, a ferromagnetic insulating SrFeO is provided.2.0 A method for transferring thin films onto a Si-based substrate includes the following steps:

[0007] (1) A water-soluble Sr3Al2O6 thin film was prepared on a YAlO3 single crystal substrate using pulsed laser deposition technology as a sacrificial layer to obtain an Sr3Al2O6 / YAlO3 heterojunction; the thickness of the Sr3Al2O6 thin film was 2-15 nm.

[0008] (2) Preparation of SrFeO on the Sr3Al2O6 face of the Sr3Al2O6 / YAlO3 heterostructure 2.0 Thin film, to obtain SrFeO 2.0 / Sr3Al2O6 / YAlO3 heterojunction; the SrFeO 2.0 The thickness of the thin film is 2-50 nm;

[0009] (3) SrFeO 2.0 / Sr3Al2O6 / YAlO3 heterojunction SrFeO 2.0 The surface is adhered to a polymer sheet, and then immersed in a deionized aqueous solution to dissolve the Sr3Al2O6 film, thus realizing SrFeO 2.0 The thin film was separated from the YAlO3 single crystal substrate to obtain SrFeO. 2.0 / Polymer sheet heterojunction; the polymer sheet is one of PET (ethylene glycol phthalate) and PDMS (polydimethylsiloxane);

[0010] (4) The SrFeO obtained in step (3) 2.0 SrFeO / polymer sheet heterostructure 2.0 The polymer film is adhered to a Si-based semiconductor substrate and immersed in an acetone solution to remove the polymer film, thus realizing SrFeO. 2.0 The transfer of the thin film on a Si-based semiconductor substrate yields SrFeO. 2.0 / Si heterojunction; in step (3), SrFeO 2.0 After the thin film is separated from the YAlO3 single crystal substrate, it is placed on SrFeO 2.0 SrFeO in the / Sr3Al2O6 / YAlO3 heterojunction 2.0 They have the same structure.

[0011] It should be noted that in step (1), when the thickness of Sr3Al2O6 is different, SrFeO is obtained. 2.0 The structural phases of YAlO3 differ, resulting in significant variations in its magnetic properties, primarily related to interfacial strain. The lattice constant of YAlO3 is... The lattice constant of Sr3Al2O6 bulk material is Based on the relaxation characteristics of thin film growth, as the thickness of the Sr3Al2O6 thin film gradually increases, the lattice constant of the upper surface layer of Sr3Al2O6 gradually approaches the lattice constant of its bulk material. This pair of SrFeO 2.0 The formation of new structural phases is unfavorable, but if the thickness of the Sr3Al2O6 film is too thin, it will negatively impact the formation of SrFeO. 2.0 Subsequent peeling of the film is unfavorable, and both factors need to be considered; therefore, there are certain requirements for the thickness of the Sr3Al2O6 film. In step (2), when SrFeO 2.0 When the thickness of SrFeO varies, the resulting structural phases also differ. 2.0 There are certain requirements for the thickness.

[0012] It should be noted that in step (3), SrFeO 2.0 Although the thin film is no longer supported by the interfacial stress after separation from the YAlO3 single crystal substrate, it can still inherit the SrFeO... 2.0 SrFeO in the / Sr3Al2O6 / YAlO3 heterojunction 2.0 The structure.

[0013] Furthermore, the SrFeO 2.0 The saturation magnetization of the polymer sheet heterojunction at 10K is 90-145 emu / cc.

[0014] It should be noted that SrFeO 2.0 The polymer sheets in the polymer sheet heterojunction are non-magnetic.

[0015] Preferably, the polymer sheet is PET, and the SrFeO is... 2.0 The polymer sheet heterostructure is SrFeO 2.0 / PET heterojunction, SrFeO 2.0 The saturation magnetization of the PET heterojunction at 10K is 145 emu / cc, and the SrFeO... 2.0 The saturation magnetization of the / PET heterojunction at 400K is 65 emu / cc.

[0016] Furthermore, in step (1), the Sr3Al2O6 thin film is prepared at a temperature of 700-800℃ and the deposition oxygen pressure is 20-30Pa.

[0017] Preferably, the SrFeO 2.0 The thickness of the thin film is 2-20 nm.

[0018] Preferably, the thickness of the Sr3Al2O6 thin film is 2 nm.

[0019] Furthermore, step (2) also includes the step of preparing a LaAlO3 protective layer; the specific step of preparing the LaAlO3 protective layer is as follows: in SrFeO 2.0 LaAlO3 protective layers were prepared on the upper and lower surfaces of the thin film at a temperature of 550-650℃ and an oxygen deposition pressure of 1.0 × 10⁻⁶. -6 Pa; the thickness of the LaAlO3 protective layer is ≤3.0 nm.

[0020] Furthermore, in step (3), the soaking temperature is 20-60℃ and the soaking time is 5-70h.

[0021] Furthermore, in step (4), the soaking temperature is 30-50℃ and the soaking time is 10-20h.

[0022] Furthermore, the laser source for the pulsed laser deposition technology is a KrF excimer laser with a wavelength of 248 nm, a laser pulse width of 10 ns, and a laser energy density of 1.0 J / cm². 2 -3.0J / cm 2 The laser frequency is 2Hz-5Hz.

[0023] Furthermore, the SrFeO 2.0 The saturation magnetization of the / Sr3Al2O6 / YAlO3 heterojunction at 10K is 120-170 emu / cc.

[0024] When SrFeO 2.0 When the film thickness is 20 nm, the SrFeO 2.0 The saturation magnetization of the / Sr3Al2O6 / YAlO3 heterojunction at 10K is 170 emu / cc. The SrFeO... 2.0 The saturation magnetization of the / Sr3Al2O6 / YAlO3 heterojunction at 400K is 90 emu / cc.

[0025] Secondly, it provides ferromagnetic insulating SrFeO as described in the first aspect. 2.0 SrFeO thin film prepared by transfer method on Si substrate 2.0 / Si heterojunction.

[0026] Furthermore, the SrFeO 2.0 The saturation magnetization of the / Si heterojunction at 10K is 70-150 emu / cc.

[0027] Preferably, the SrFeO 2.0 The saturation magnetization of the / Si heterojunction at 400K is 35-69 emu / cc.

[0028] Thirdly, it provides ferromagnetic insulating SrFeO as described in the first aspect. 2.0 Application of thin film transfer methods on Si substrates in semiconductor devices.

[0029] In order to make SrFeO 2.0 Thin-film device fabrication, adaptable to current magnetic storage device applications. In this invention, SrFeO... 2.0 The preferred film thickness is 2-20 nm. For SrFeO 2.0 Epitaxial growth of thin films, if no sacrificial layer is used (SrFeO is directly prepared on a single crystal substrate) 2.0 In the case of thin films, within a certain range, the smaller the lattice constant of the single-crystal substrate, the more favorable it is for SrFeO. 2.0 Improved thin film magnetism (appropriate compressive strain is beneficial to SrFeO) 2.0 The formation of a new phase in the thin film is also the reason for its good magnetic properties. In this invention, a YAlO3 single-crystal substrate with a relatively low lattice constant is mainly used. The Sr3Al2O6 thin film, as a sacrificial layer, has a low lattice constant. The lattice constant is larger than that of the YAlO3 single-crystal substrate used, which is unfavorable to the expected results (according to the growth characteristics of single-crystal epitaxial films, if the Sr3Al2O6 film is thicker, the SrFeO...). 2.0 The compressive stress on the film is diluted by the Sr3Al2O6 film, preventing the formation of a new phase and resulting in poor magnetic properties. Therefore, this invention aims to reduce the impact of the sacrificial layer on SrFeO. 2.0 To mitigate the influence of thin film magnetism and ensure complete separation of the thin film and the single-crystal substrate, the "dilution" effect of the Sr3Al2O6 sacrificial layer on the interfacial strain of the single-crystal substrate is reduced by altering its thickness. In this invention, a Sr3Al2O6 film thickness of 2-20 nm can ensure the separation of the SrFeO... 2.0 The film can be completely peeled off, but its magnetic properties decrease continuously with increasing Sr3Al2O6 film thickness, especially above 10 nm for SrFeO. 2.0 Since the thin film has almost no hysteresis loop at 400K, a thickness of 2nm is more preferred for the Sr3Al2O6 thin film.

[0030] In addition, the present invention utilizes SrFeO 2.0 The optimization of the thin film peeling process and the post-peeling adhesion to PET and Si substrates has achieved SrFeO 2.0 Thin film peeled from rigid single crystal film (SrFeO) 2.0 After the film is subjected to compressive strain away from the rigid substrate, SrFeO 2.0 The new thin film structure can still exist (and has good magnetic properties), and SrFeO has also been achieved. 2.0 The transfer of thin films to flexible substrates and Si-based semiconductor devices, in this invention, SrFeO2.0 The crystal structure and magnetic properties did not change significantly before and after the thin film peeling and transfer, providing some ideas for the flexibility and wearability of devices. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 is the XRD pattern of the Sr3Al2O6 / YAlO3 heterojunction in Example 1 of the present invention;

[0033] Figure 2 shows the SrFeO in Experimental Example 1 of this invention. 2.0 / Sr3Al2O6 / YAlO3 heterojunction, SrFeO 2.0 / PET heterojunction, SrFeO 2.0 XRD pattern of a Si heterojunction;

[0034] Figure 3 shows the SrFeO in Experimental Example 1 of this invention. 2.0 / Sr3Al2O6 / YAlO3 heterojunction, SrFeO 2.0 / PET heterojunction, SrFeO 2.0 / Si heterojunction MT diagram at 10K-400K;

[0035] Figure 4 shows the SrFeO in Experimental Example 1 of this invention. 2.0 / Sr3Al2O6 / YAlO3 heterojunction, SrFeO 2.0 / PET heterojunction, SrFeO 2.0 MH curve of / Si heterojunction at 400K;

[0036] Figure 5 shows the SrFeO in Experimental Example 1 of this invention. 2.0 A schematic diagram of the growth, peeling, and transfer of thin films on a YAlO3 single-crystal substrate;

[0037] Figure 6 shows the SrFeO in Experiment Examples 1-4 of this invention. 2.0 SrFeO is formed when the thin film is 20nm, 10nm, 5nm, or 2nm. 2.0 MT diagram of / Si heterojunction in 10K-400K;

[0038] Figure 7 shows the SrFeO in Experiment Examples 1-4 of this invention. 2.0 SrFeO is formed when the thin film is 20nm, 10nm, 5nm, or 2nm. 2.0 MH curve of / Si heterojunction at 400K;

[0039] Figure 8 shows the SrFeO in Comparative Example 1 of this invention. 2.0 XRD pattern of the / Sr3Al2O6 / YAlO3 heterojunction;

[0040] Figure 9 shows the SrFeO in Comparative Example 1 and Experimental Example 1 of the present invention. 2.0 MT comparison of / Sr3Al2O6 / YAlO3 heterojunction at 10K-400K;

[0041] Figure 10 shows the SrFeO in Comparative Example 2 of the present invention. 2.0 XRD pattern of the / Sr3Al2O6 / YAlO3 heterojunction;

[0042] Figure 11 shows the SrFeO in Comparative Example 2 and Experimental Example 1 of the present invention. 2.0 / Comparison of MT values ​​for PET heterojunctions at 10K-400K. Detailed Implementation

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] Example 1

[0045] Selected crystal plane orientation is <001> The YAlO3 (YAO) single crystal substrate has a lattice constant of Pulsed laser deposition technology was used (the laser source for pulsed laser deposition was a KrF excimer laser with a wavelength of 248 nm, a laser pulse width of 10 ns, and a laser energy density of 1.0 J / cm²). 2 A water-soluble Sr3Al2O6 (SAO) film was prepared as a sacrificial layer by bombarding a Sr3Al2O6 target on a YAO single crystal substrate with a laser frequency of 2Hz. The SAO film was prepared at a temperature of 800℃ and an oxygen deposition pressure of 28Pa to obtain a Sr3Al2O6 / YAlO3 heterojunction (SAO / YAO heterojunction). The thickness of the SAO film was 20nm. The XRD pattern of the Sr3Al2O6 / YAlO3 heterojunction is shown in Figure 1.

[0046] Experimental Example 1

[0047] Selected crystal plane orientation is <001> The YAlO3 (YAO) single crystal substrate has a lattice constant of Pulsed laser deposition technology was used (the laser source for pulsed laser deposition was a KrF excimer laser with a wavelength of 248 nm, a laser pulse width of 10 ns, and a laser energy density of 1.0 J / cm²). 2 A water-soluble Sr3Al2O6 (SAO) film was prepared as a sacrificial layer by bombarding a Sr3Al2O6 target on a YAO single crystal substrate with a laser frequency of 2Hz. The SAO film was prepared at a temperature of 700℃ and a deposition oxygen pressure of 20Pa to obtain an Sr3Al2O6 / YAlO3 heterojunction (SAO / YAO heterojunction). The thickness of the SAO film was 2nm.

[0048] SrFeO was prepared on the Sr3Al2O6 facet of the SAO / YAO heterostructure. 2.0 (abbreviated as SFO, the same below) thin film, to obtain SrFeO thin film, to obtain SrFeO 2.0 The Sr3Al2O6 / YAlO3 heterojunction (hereinafter referred to as SFO / SAO / YAO heterojunction) has a thickness of 20 nm. XRD analysis was performed on the SFO / SAO / YAO heterojunction, and the results are shown in Figure 2 (here, the SAO layer is too thin to be detected by X-rays).

[0049] SrFeO 2.0 The thin film preparation steps are as follows: First, SrFeO is prepared using pulsed laser deposition technology. 2.5 The thin film was prepared at 700℃ with a deposition oxygen pressure of 1 Pa; it was then mixed with calcium hydride in a vacuum and sintered at 300℃ for more than 100 h to obtain SrFeO. 2.0 film.

[0050] In this embodiment, SrFeO 2.0 The thin film preparation steps also include SrFeO 2.0 The steps for preparing LaAlO3 protective layers on the upper and lower surfaces of the thin film are as follows: the preparation temperature of the LaAlO3 protective layer is 550℃, and the deposition oxygen pressure is 1.0 × 10⁻⁶. -6 Pa; the thickness of the LaAlO3 protective layer is 2 nm, resulting in LaAlO3 / SrFeO 2.0 In the case of a LaAlO3 heterojunction, the LaAlO3 protective layer provides protection and has no significant impact on the peeling and transfer process or the testing of magnetic properties. Therefore, the LaAlO3 layer is no longer mentioned after the film is grown; it is uniformly referred to as SrFeO. 2.0 film.

[0051] SrFeO in SFO / SAO / YAO heterojunction 2.0The surface of the SAO film was adhered to PET and then immersed in a deionized water solution at 20°C for 50 hours to dissolve the SAO film, thus separating the SAO film from the YAO single-crystal substrate to obtain SrFeO. 2.0 / PET heterojunction (hereinafter referred to as SFO / PET heterojunction). XRD tests were performed on it, as shown in Figure 2.

[0052] SrFeO in SFO / PET heterojunction 2.0 Surface adheres to having <001> On an oriented Si-based semiconductor substrate, the film is immersed in an acetone solution at 30°C for 10 hours to remove PET, thereby achieving the transfer of the SFO film onto the Si-based semiconductor substrate and obtaining SrFeO. 2.0 The SFO / Si heterojunction (hereinafter referred to as SFO / Si heterojunction) was subjected to XRD testing, as shown in Figure 2.

[0053] The three heterojunctions (SFO / SAO / YAO, SFO / PET, SFO / Si) from the above steps were placed in a comprehensive physical property measurement system for corresponding magnetic performance tests. The saturation magnetization versus temperature curve (M–T plot) from 10K to 400K is shown in Figure 3, and the hysteresis loop (M–H curve) at 400K is shown in Figure 4. Figure 5 shows the SrFeO... 2.0 A schematic diagram of the growth, peeling, and transfer of the thin film on a YAlO3 single-crystal substrate. X-ray diffraction analysis and magnetic testing results indicate that SrFeO... 2.0 Before and after the thin film is peeled off and transferred from the single-crystal substrate, its crystal structure and magnetic properties remain largely unchanged, providing new ideas and material support for fundamental and applied research related to the realization of high-temperature ferromagnetic insulating oxide thin film devices.

[0054] Experimental Example 2

[0055] The difference between Experimental Example 2 and Experimental Example 1 is that the thickness of the SFO film is 10 nm.

[0056] Experimental Example 3

[0057] The difference between Experimental Example 3 and Experimental Example 1 is that the thickness of the SFO film is 5 nm.

[0058] Test Example 4

[0059] The difference between Experimental Example 4 and Experimental Example 1 is that the thickness of the SFO film is 2 nm.

[0060] The magnetic properties of the SFO / Si heterojunction tested in Examples 1-4 are shown in Figure 6 (M-T curves at 10K-400K) and Figure 7 (M-H curve at 400K). Figures 6 and 7 show that the magnetism decreases with decreasing film thickness, especially between 5nm and 2nm. When SrFeO... 2.0 The saturation magnetization at 400K temperature is 32 emu / cc when the film thickness is 2nm, which meets the basic requirements for its use as a tunneling layer material for magnetic memory.

[0061] Comparative Example 1

[0062] The difference between Comparative Example 1 and Experimental Example 1 is that the thickness of the SFO film is 60 nm.

[0063] When the thickness of the prepared SFO film is 60 nm, the effect on SrFeO 2.0 XRD analysis was performed on the / Sr3Al2O6 / YAlO3 heterojunction, as shown in Figure 8. The final SrFeO was obtained. 2.0 The phase is not the phase we need (assuming SAO is 2nm, when SrFeO 2.0 When the thickness is below 20 nm, the X-ray diffraction peak 2θ angle we obtained is 46.53°, while when the thickness is 60 nm, the XRD peak 2θ angle is 52.01°. Both are the same material, but with different phase structures. The material exhibits better magnetic properties when the 2θ angle is 46.53°, and its formation is related to interfacial strain. Therefore, this invention imposes limitations on the thickness of SFO and SAO films. 2.0 Figure 9 shows the M-T curves of the / Sr3Al2O6 / YAlO3 heterojunction at 10K-400K. It can be seen that the magnetic properties are relatively weak and not of great significance to the research of this invention.

[0064] Comparative Example 2

[0065] The difference between Comparative Example 2 and Experimental Example 1 is that the thickness of the SAO film is 20 nm.

[0066] When the thickness of the SAO film is 20 nm and the thickness of the SFO film is 20 nm, what is the effect on SrFeO? 2.0 XRD analysis of the Sr3Al2O6 / YAlO3 heterojunction was performed, as shown in Figure 10. The final SFO phase was not the desired phase (when the SAO film thickness was 20 nm, the 2θ angle of the SFO film's X-ray diffraction peak was 52.2°, not the approximately 46° 2θ angle X-ray diffraction peak. This was mainly because the large lattice constant of the bulk SAO material diluted the interfacial strain between the YAO single-crystal substrate and the SFO film). SrFeO 2.0Figure 11 shows the M-T curves of the SFO / PET heterojunction at 10K-400K. It can be seen that the SFO / PET heterojunction formed after exfoliation has weak magnetism and is not of great significance to the research of this invention. In summary, this invention achieves SrFeO2 heterojunction by introducing a water-soluble sacrificial layer. 2.0 The peeling of the thin film from the original rigid substrate, and its transfer to other flexible or Si substrates, provides material support and technical foundation for the development of high-temperature, low-dissipation quantum ferromagnetic insulated spin-integrated electronic devices.

[0067] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0068] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A ferromagnetic insulating SrFeO 2.0 The method for transferring thin films on a Si substrate is characterized by, Includes the following steps: (1) A water-soluble Sr3Al2O6 thin film is prepared on a YAlO3 single crystal substrate using pulsed laser deposition technology as a sacrificial layer to obtain a Sr3Al2O6 / YAlO3 heterojunction; the thickness of the Sr3Al2O6 thin film is 2-15 nm; (2) SrFeO is prepared on the Sr3Al2O6 surface of the Sr3Al2O6 / YAlO3 heterojunction. 2.0 Thin film, to obtain SrFeO 2.0 / Sr3Al2O6 / YAlO3 heterojunction; the SrFeO 2.0 The thickness of the film is 2-50 nm; (3) SrFeO 2.0 SrFeO heterostructure of / Sr3Al2O6 / YAlO3 2.0 The surface is adhered to a polymer sheet, and then immersed in a deionized aqueous solution to dissolve the Sr3Al2O6 film, thus realizing SrFeO 2.0 The thin film was separated from the YAlO3 single crystal substrate to obtain SrFeO. 2.0 / Polymer sheet heterojunction; the polymer sheet is one of PET and PDMS; (4) the SrFeO obtained in step (3) 2.0 SrFeO / polymer sheet heterostructure 2.0 The polymer film is adhered to a Si-based semiconductor substrate and immersed in an acetone solution to remove the polymer film, thus realizing SrFeO. 2.0 The transfer of the thin film on a Si-based semiconductor substrate yields SrFeO. 2.0 / Si heterojunction; in step (3), SrFeO 2.0 After the thin film is separated from the YAlO3 single crystal substrate, it is placed on SrFeO 2.0 SrFeO in the / Sr3Al2O6 / YAlO3 heterojunction 2.0 The structures are the same; step (2) also includes the step of preparing a LaAlO3 protective layer; the specific step of preparing the LaAlO3 protective layer is: in SrFeO 2.0 LaAlO3 protective layers were prepared on the upper and lower surfaces of the thin film at a temperature of 550-650 ℃ and an oxygen deposition pressure of 1.0 × 10⁻⁶. -6 Pa; the thickness of the LaAlO3 protective layer is ≤ 3.0 nm.

2. The ferromagnetic insulating SrFeO as described in claim 1 2.0 The method for transferring thin films on a Si substrate is characterized by, The SrFeO 2.0 The saturation magnetization of the polymer sheet heterojunction at 10K is 90-145 emu / cc.

3. The ferromagnetic insulating SrFeO as described in claim 2 2.0 The method for transferring thin films on a Si substrate is characterized by, In step (1), the Sr3Al2O6 thin film is prepared at a temperature of 700-800℃ and the deposition oxygen pressure is 20-30 Pa.

4. The ferromagnetic insulating SrFeO as described in claim 1 2.0 The method for transferring thin films on a Si substrate is characterized by, In step (3), the soaking temperature is 20-60℃ and the soaking time is 5-70h.

5. The ferromagnetic insulating SrFeO as described in claim 4 2.0 The method for transferring thin films on a Si substrate is characterized by, In step (4), the soaking temperature is 30-50℃ and the soaking time is 10-20h.

6. The ferromagnetic insulating SrFeO as described in claim 5 2.0 The method for transferring thin films on a Si substrate is characterized by, The laser source for the pulsed laser deposition technology is a KrF excimer laser with a wavelength of 248 nm, a pulse width of 10 ns, and a laser energy density of 1.0 J / cm². 2 -3.0 J / cm 2 The laser frequency is 2Hz-5Hz.

7. The ferromagnetic insulating SrFeO as described in any one of claims 1-6 2.0 SrFeO thin film prepared by transfer method on Si substrate 2.0 / Si heterojunction.

8. The ferromagnetic insulating SrFeO as described in claim 7 2.0 SrFeO thin film prepared by transfer method on Si substrate 2.0 / Si heterojunction, characterized in that The SrFeO 2.0 The saturation magnetization of the / Si heterojunction at 10K is 70-150 emu / cc.

9. The ferromagnetic insulating SrFeO as described in any one of claims 1-6 2.0 Application of thin film transfer methods on Si substrates in semiconductor devices.

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