Spinning electronic device, preparation method and application thereof

Abstract

The invention discloses a spinning electronic device, a preparation method and application thereof, and the preparation method comprises the following steps: 1, depositing a Pt thin film layer on the surface of a substrate under a vacuum condition, and carrying out the in-situ argon plasma processing of the Pt thin film layer; and 2, sequentially depositing a Py ferromagnetic layer and a SiN2 layer on the surface of the Pt thin film treated in the step 1. The preparation method is simple in process and high in compatibility, the prepared spin electronic device has high spin transparency and spin orbit torque efficiency, defects caused by introduction of an additional structure or change of a thin film layer structure are effectively avoided, and SOT efficiency is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the technical field of spintronic devices, specifically relating to a spintronic device for improving spin-orbit torque efficiency, its preparation method, and its application. Background Technology

[0002] Spin-orbit torque (SOT) is the interaction between the spin current generated in the spin source layer and the magnetization of the adjacent magnetic layer. It allows for efficient electro-longitudinal magnetization directions. Due to its efficient and low-power magnetic moment manipulation capabilities, this technology has broad application prospects in next-generation non-volatile memories and logic devices. Its efficiency is usually expressed as: ,in, θ SH For the spin Hall angle, T int For interface spin transparency. Although early studies of spin-orbit torque were based on heavy metal Pt / Co heterostructures, Pt exhibits a relatively low spin Hall angle. Therefore, compared to conventional heavy metals, given... θ SH Its role in SOT-related research, and in identifying those with high... θ SH New materials are naturally an improvement The central stages of this process include topological insulators, transition metal dichalcogenides, and oxide interfaces. However, these alternative materials typically involve complex manufacturing processes and suffer from poor thermal / chemical stability and high longitudinal resistivity, limiting their practical applications.

[0003] In recent years, controlling the spin current transport efficiency at nonmagnetic / ferromagnetic (NM / FM) interfaces has become a focus. T int In determining The interface also plays a crucial role. When the interface restricts spin current transport, the measured spin current in the NM / FM two-layer system... It can be significantly lower than the theoretical prediction value, even for those with a large [value / probability]. θ SH The same applies to the NM layer. Therefore, interface engineering becomes crucial for improvement. T int Effective approaches include inserting ultrathin metal spacers or oxide layers, but these methods introduce additional complexity, current shunting, and spin decay issues. Therefore, developing a simple, controllable, and layer-free interface optimization method is of great significance for promoting the development of SOT devices. Summary of the Invention

[0004] One objective of this invention is to address the shortcomings of existing technologies by providing a method for fabricating electronic devices that improves spin-orbit torque efficiency. This method is simple, highly compatible, and produces spintronic devices with high spin transparency and spin-orbit torque efficiency. It effectively avoids the drawbacks caused by introducing additional structures or changing the thin film layer structure, and significantly improves SOT efficiency.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for fabricating electronic devices with improved spin-orbit torque efficiency includes the following steps: Step 1: Deposit a Pt thin film layer on the substrate surface under vacuum conditions, and then perform in-situ argon plasma treatment on the Pt thin film layer; Step 2: Sequentially deposit a Py ferromagnetic layer and a SiN2 layer on the surface of the Pt thin film treated in Step 1.

[0006] Furthermore, in steps 1 and 2, the vacuum level is lower than... .

[0007] Furthermore, the thickness of the Pt thin film deposited in step 1 is 3-6 nm.

[0008] Further, in step 1, Ar gas is introduced, and plasma treatment is performed by applying a power of 26-40 W and a gas pressure of 1-6 mTorr.

[0009] Furthermore, the in-situ argon plasma treatment time in step 1 t p It lasts 5-20 seconds.

[0010] Furthermore, in step 2, the Py layer deposition thickness is 6-8 nm, and the SiN2 layer deposition thickness is 3-5 nm.

[0011] A spintronic device prepared according to the above-described method for improving spin-orbit torque efficiency.

[0012] Furthermore, the interface spin transparency of the spintronic device T int Spin-orbit torque efficiency not less than 0.9 Not less than 0.1.

[0013] An application of the spintronic device described above, wherein the spintronic device is used in a spin-orbit torque driven magnetic memory or logic device.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides an interface optimization method without the need for an insertion layer. Compared with the traditional interface engineering methods mentioned above, this invention can treat non-magnetic / ferromagnetic interfaces in situ, that is, treat the Pt thin film layer with argon plasma, which significantly improves the interface spin transparency and thus significantly improves the SOT efficiency, achieving a large value within the optimized treatment time. Importantly, it eliminates alternative mechanisms such as resistivity, thickness, or saturation magnetization, confirming that the improvement in spin transparency mainly comes from interface modification. After plasma treatment, the interface roughness is reduced, which weakens the interface spin-orbit coupling, thereby suppressing spin memory loss. This allows the spin current generated by the spin source layer to be efficiently transmitted to the ferromagnetic layer, while avoiding the introduction of additional structures or changes to the thin film layer architecture. It is an ideal and more effective method with simple process, strong controllability, and is suitable for high-performance spintronic devices. It is compatible with existing semiconductor processes, has good prospects for industrialization, and lays an important experimental foundation for building advanced spintronic devices. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the fabrication process of the spintronic device according to an embodiment of the present invention; Figure 2 The XRR spectrum of the Pt / Py heterojunction in the spintronic device prepared according to an embodiment of the present invention; Figure 3 The hysteresis loop of the Pt / Py heterojunction of the spintronic device prepared in the embodiment of the present invention; Figure 4 (a) is a schematic diagram of the spintronic device and its measurement configuration prepared according to an embodiment of the present invention, and (b) is a comparative example of a Pt / Py thin film with a frequency range of 5.5 to 8 GHz. t p Representative ST-FMR spectrum (Vmix) of (=0s); Figure 5 The 7 GHz spectrum of the spintronic device prepared for the embodiments of the present invention and the corresponding symmetric and antisymmetric components plotted after fitting, wherein, (a) comparative example t p =0s, (b) is Example 1 t p =15s; Figure 6 The resonant field measured by the spintronic device prepared for the embodiments of the present invention ( H res ) frequency Dependencies, where the red open square ( t p = 0s) and blue open circle ( t p=15s) represents experimental data, and solid curves represent fitting data using the Kittel equation; Figure 7 For the purpose of this invention, in comparative examples t p = 0 s and Example 1 t p Spin-orbit torque efficiency dependence of spintronic device frequency obtained at 15s; Figure 8 Various performance parameters of the spintronic devices prepared in the embodiments of the present invention and in-situ Ar plasma treatment time t p The functional relationship, (a) spin-orbit torque efficiency of the Pt / Py double layer. ζ SOT (b) Longitudinal resistivity of Pt thin film r (c) Thickness of the Pt (orange) and Py (purple) layers, (d) Saturation magnetization of the Py layer. M s ; Figure 9 Various parameters of the spintronic device prepared for embodiments of the present invention and in-situ Ar plasma treatment time t p The functional relationship, (a) the frequency of the ferromagnetic resonance linewidth. (a) Dependence, (b) Gilbert damping constant, (c) Effective spin mixing conductance, (d) Spin transparency at the interface T int ; Figure 10 The graph shows the relationship between the surface roughness of the spintronic device prepared according to an embodiment of the present invention and the plasma treatment time. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0018] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0019] Example 1

[0020] like Figure 1As shown, a method for fabricating an electronic device to improve spin-orbit torque efficiency includes the following steps: (1) The substrate was cleaned using ultrasound and then fixed onto the sample tray. (2) The sample tray with the fixed substrate is transferred to the sputtering chamber through the sample transfer rod. The substrate is treated using an ultra-high vacuum magnetron sputtering system. The sample tray is first placed in a small chamber for pretreatment. The vacuum level in the small chamber is lower than that in the small chamber. It is then fed into a large chamber, where the vacuum level is lower than that of a smaller chamber. After the sample is sent into the large chamber, the sample stage rotation button is turned on to introduce argon gas and deposit a 5 nm Pt thin film layer. (3) Ar gas (10 sccm) was continuously introduced into the large chamber, and a power of 32W and a gas pressure of 3 mTorr were applied to perform plasma treatment on the surface of the Pt thin film layer. The treatment time was as follows: t p The time is 15s; then, 7 nm Py and 5 nm SiN2 layers are sequentially sputtered and deposited on the surface of the Pt thin film to obtain a device with a Pt / Py heterojunction bilayer film structure.

[0021] Finally, the obtained Pt / Py / SiN2 was photolithographically fabricated into a 100 μm × 10 μm strip. Through processes such as ultraviolet exposure and argon ion etching, the strip was fabricated into a standard spin torque ferromagnetic resonance (ST-FMR) device using overlay technology. Wires were led out from the three electrodes using aluminum wires and high-frequency electrical transport tests were performed, confirming that plasma treatment can significantly improve the SOT driving efficiency.

[0022] Example 2

[0023] Unlike Example 1, this example prepares a Pt thin film layer surface subjected to plasma treatment for a time of [duration missing]. t p Spintronic devices with values ​​of 5, 10, and 20 s, respectively.

[0024] Example 3

[0025] Unlike Example 1, a power of 26 W and a gas pressure of 1 mTorr were applied during plasma treatment, and Py layers with a thickness of 6 nm and SiN2 layers with a thickness of 3 nm were sequentially sputtered and deposited on the surface of the Pt thin film.

[0026] Example 4

[0027] Unlike Example 1, a power of 40 W and a gas pressure of 6 mTorr were applied during plasma treatment, and Py layers with a thickness of 8 nm and SiN2 layers with a thickness of 4 nm were sequentially sputtered and deposited on the surface of the Pt thin film.

[0028] Based on the plasma treatment steps (1)-(3) above, the spin-transfer efficiency is regulated by the spin angular momentum transfer efficiency at the interface, and the spin angular momentum transfer efficiency can be quantitatively characterized by spin transparency. The strip was fabricated into an ST-FMR device and subjected to electrical transport testing. The results showed that the spin transparency of the plasma-treated device was significantly improved, which can be used for spin-orbit torque driven magnetic memories or logic devices to reduce energy consumption and improve efficiency.

[0029] In a spin-orbit torque-driven magnetic memory of a certain size, according to Joule's law, the energy consumed during spin-orbit storage write operations is proportional to the magnetization reversal time and the square of the current. While keeping the ferromagnetic layer structure unchanged, energy consumption can be further reduced by improving the system's spin-transformation efficiency.

[0030] To illustrate the effects of the embodiments of the present invention, an electronic device prepared without in-situ argon plasma treatment (the remaining steps are the same as in Example 1) was used as a comparative example. The spin transparency of the non-magnetic / ferromagnetic interface of the electronic device was characterized by ST-FMR, and the roughness of the non-magnetic / ferromagnetic interface was characterized by XRR. Figure 2 As shown, the interface roughness was measured by XRR, and the fitting results matched well with the recorded XRR curves. The thicknesses of all layers were consistent with the nominal values. For interface roughness, clear Kiessig fringes were observed throughout the measurement range, indicating excellent film quality. Figure 3 As shown, the saturation magnetization M of the sample s Both are around 810 emu / cc.

[0031] The test diagram is shown below, obtained through ST-FMR measurement. Figure 4 As shown in (a), a radio frequency (RF) current is applied along the longitudinal direction of the device, and an in-plane magnetic field (H) ext The image is scanned at a 45° angle relative to the RF current direction. The RF current flowing through the Pt layer is converted into a transversely oscillating spin current, which in turn generates an oscillating spin-orbit torque in the Py layer. Figure 4(b) shows the Pt / Py thin film at t p Representative V under the condition of 0 s mix Spectrum, frequency It varies from 5.5 to 8 GHz. This result indicates that V mix Signal follows The variation is consistent with predictions of voltage generation induced by spin-torque driven ferromagnetic resonance (ST-FMR). The fitted graph of the results is shown below. Figure 5 As shown, the symmetric component V S and antisymmetric component V A The effect is significantly enhanced by argon plasma treatment. Figure 6 Frequency was displayed With resonance field H res The correlation between them is used to estimate the effective magnetization M of the Py layer. eff The effective magnetization M eff As a calculation The median of efficiency.

[0032] In order to quantitatively characterize the changes in SOT, Figure 7 Drawing in The results indicate a frequency dependence. Frequency-independent, this supports the view that the observed Vmix signal is primarily dominated by ST-FMR. The inverse spin Hall voltage caused by spin pumping and thermoelectric effects is negligible in the measured signal. Meanwhile... Enhancement was achieved through argon plasma interface treatment. For t p = 0 s Pt / Py thin film, The average value is 0.080 to 0.088; while for t p = 15 s Pt / Py thin film, The spin-orbit torque efficiency ranges from 0.121 to 0.131. The improvement is approximately 50%. For example, in Example 2, t... p Calculations were performed on Pt / Py films with s = 5, 10, and 20 s. All are higher than 0.1.

[0033] Multiple sets of experiments treated with plasma were compared with those without plasma treatment, such as... Figure 8 As shown in (a), the display In t p = monotonically increasing 15 s ago, while when t p It decreases slightly after 15 seconds. (For example...) Figure 8 (a), (b), and (c) show the longitudinal resistivity (ρ) of the Pt layer, respectively. xx Thickness variations of Pt and Py layers and M of Py layer s With t p The increase remained almost constant, ruling out the influence of plasma treatment on the bulk effects of altering the Pt and Py layers. The possibility.

[0034] like Figure 9 (a) Δ H and The relationship remains strictly linear across the entire frequency range without deviation, indicating that the contribution of the two-magnetic-particle scattering mechanism in the thin film is negligible. The calculated Gilbert damping constant... As summarized in Figure 9(b), this constant can be used to calculate the effective spin hybrid conductance. Figure 9(c) shows Follow t p The change initially shows an increasing trend, reaches its maximum value, and then eventually decreases. The change indicates that the spin transport characteristics of the Pt / Py interface have changed.

[0035] Further investigation is needed into the spin transport properties of the Pt / Py interface, such as... Figure 10 As shown, the results indicate that argon plasma treatment reduces the interface roughness, which weakens the interfacial spin-orbit coupling (ISOC) and thus suppresses spin memory loss (SML). Meanwhile, the interfacial magnetic anisotropy K... s The decrease in SML with increasing plasma treatment time further supports this. Therefore, as Figure 9 As shown in (e), this enhancement is attributed to the interface spin transparency T. int The improvement was calculated. T int exist t p The value can reach approximately 0.95 at 15s. For example, t in Example 2... p Calculations were performed on Pt / Py films with s = 5, 10, and 20 s. T int All are above 0.9.

[0036] Importantly, by ruling out alternative mechanisms such as resistivity, thickness, or saturation magnetization, the improved spin transparency was confirmed to primarily stem from interface modification. This invention highlights the potential of argon plasma as a simple, scalable, and compatible interface engineering technique in spintronic heterostructures.

[0037] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. A method for fabricating electronic devices with improved spin-orbit torque efficiency, characterized in that, Includes the following steps: Step 1: Deposit a Pt thin film layer on the substrate surface under vacuum conditions, and then perform in-situ argon plasma treatment on the Pt thin film layer; Step 2: Sequentially deposit a Py ferromagnetic layer and a SiN2 layer on the surface of the Pt thin film treated in Step 1.

2. The method for fabricating electronic devices with improved spin-orbit torque efficiency according to claim 1, characterized in that, The vacuum level in steps 1 and 2 is lower than .

3. The method for fabricating electronic devices with improved spin-orbit torque efficiency according to claim 1, characterized in that, The thickness of the Pt thin film deposited in step 1 is 3-6 nm.

4. The method for fabricating electronic devices with improved spin-orbit torque efficiency according to claim 1, characterized in that, In step 1, Ar gas is introduced, and plasma treatment is performed by applying a power of 26-40 W and a gas pressure of 1-6 mTorr.

5. The method for fabricating electronic devices with improved spin-orbit torque efficiency according to claim 1, characterized in that, In-situ argon plasma treatment time in step 1 t p It lasts 5-20 seconds.

6. The method for fabricating electronic devices with improved spin-orbit torque efficiency according to claim 1, characterized in that, In step 2, the Py layer is deposited to a thickness of 6-8 nm, and the SiN2 layer is deposited to a thickness of 3-5 nm.

7. A spintronic device prepared by the method for improving spin-orbit torque efficiency according to any one of claims 1-6.

8. The spintronic device according to claim 1, characterized in that, The interface spin transparency of the spintronic device T int Spin-orbit torque efficiency not less than 0.9 ζ SOT Not less than 0.

1.

9. An application of the spintronic device according to any one of claims 7 or 8, characterized in that, The spintronic device is used for a magnetic memory or logic device driven by spin orbital torque.

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