Preparation method of ferronickel film

Abstract

A preparation method of a ferronickel film relates to an electronic material technology, and comprises the following steps: step 1, cleaning a Si (100) substrate, a Ni target material and a Fe target material; secondly, an ultrahigh vacuum magnetron sputtering coating process is utilized, a Fe target material and a Ni target material are sputtered together, and a NiFe thin film is deposited on the surface of the substrate; the method is characterized in that in the step 2, the Ni target and the Fe target are subjected to direct current sputtering, and the material ratio of the NiFe film is controlled through the following formula: R = a * (2.471 * S-0. 3), where 0.94 lt; a < lt >; 1.07). Wherein R is equal to Ni atom ratio / Fe atom ratio, S is equal to Ni target sputtering power / Fe target sputtering power, and the Ni target sputtering power and the Fe target sputtering power are both in the range of 10W-200W. According to the method, the ratio of the nickel to the iron in the nickel-iron film can be accurately predicted, regulated and controlled according to the sputtering power of the nickel-iron double targets, and the process cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to electronic material technology, in particular to thin film material preparation technology. Background Art

[0002] As electronic communication systems develop towards high frequency bands, miniaturization, and integration, related electronic components have also put forward new requirements for their supporting materials. Nickel-iron film has excellent magnetic properties with high magnetic permeability and low coercivity, and its saturation magnetization intensity is 4πM. s Up to 16000Gs, starting magnetic permeability μ i Up to 3000, while the coercive force H c It can be as low as 0.8Oe or less. Nickel-iron thin films can be prepared through a variety of methods such as magnetron sputtering, evaporation coating, and electroplating. These methods are highly controllable and repeatable, and can precisely control the thickness, composition, and structure of the film. At the same time, they are compatible with semiconductor and microfabrication processes, making it easy to integrate nickel-iron thin films into various micro-nano devices and integrated circuits, achieving multifunctional integration.

[0003] The saturation magnetization intensity of Fe-based materials is high, while that of Ni-based materials is relatively low. However, the magnetocrystalline anisotropy constant of NiFe alloy is relatively small, so the magnetic moment is more easily deflected during magnetization and demagnetization, resulting in a very low coercive force and a large initial permeability. Studies have shown that Ni 46 Fe 54 The saturation magnetization intensity of the alloy is the largest when the Ni content is between 34% and 78%. s ≥10000Gs; when the Ni content is between 70% and 80%, the coercive force of the NiFe alloy is the lowest and the initial magnetic permeability is the largest.

[0004] However, current research on nickel-iron thin films primarily focuses on their preparation and properties, with relatively little research on the compositional ratio of nickel-iron thin films. Typically, studies are conducted directly on a target material with a fixed nickel-iron ratio, exploring the film preparation process. Alternatively, the compositional ratio of the nickel-iron film is roughly altered by attaching varying amounts of Fe sheets to the Ni target during sputtering. Therefore, further exploration of a method for preparing nickel-iron thin films that can accurately control the nickel-iron compositional ratio is crucial. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that, in view of the problem that the background technology cannot obtain an accurate nickel-iron content ratio in the nickel-iron film, a preparation method of the nickel-iron film with controllable component ratio is proposed.

[0006] The technical solution adopted by the present invention to solve the technical problem is that the method for preparing the nickel-iron film comprises the following steps:

[0007] Step 1: Cleaning the Si(100) substrate, Ni target and Fe target;

[0008] Step 2: Using an ultra-high vacuum magnetron sputtering coating process, Fe target and Ni target are co-sputtered to deposit a NiFe film on the substrate surface;

[0009] It is characterized in that, in the step 2, both the Ni target and the Fe target are sputtered by DC, and the material ratio of the NiFe film is controlled by the following formula:

[0010] R = a × (2.471 × S - 0.3), where 0.94 <a<1.07。

[0011] Among them, R=Ni atomic ratio / Fe atomic ratio (mol ratio), S=Ni target sputtering power / Fe target sputtering power, and the sputtering powers of Ni target and Fe target are both in the range of 10W to 200W.

[0012] Furthermore, in step 2, the magnetron sputtering conditions are as follows: the sputtering temperature is 18-25°C, the working gas is Ar gas, the working pressure is 3-7 mTorr, and the background vacuum is 3×10 -5 Pa~7×10 -5 Pa.

[0013] The step 1 is: using acetone, anhydrous ethanol and deionized water to clean the substrate in sequence, and blowing it dry with an N2 air gun; the substrate is a Si (100) substrate with a thickness of 500 nm.

[0014] The present invention provides a method for preparing a nickel-iron film with an arbitrarily adjustable composition ratio. Through a simple and convenient method, the ratio of nickel and iron in the nickel-iron film can be accurately predicted and regulated according to the sputtering power of a nickel-iron dual target, thereby greatly reducing the process cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the EDS test result diagram of step 3 in Example 1;

[0016] Figure 2 This is the EDS test result diagram of step 4 in Example 1;

[0017] Figure 3 This is the EDS test result diagram of step 4 in Example 2;

[0018] Figure 4 This is the EDS test result diagram of step 4 in Example 3;

[0019] Figure 5 This is the EDS test result diagram of step 4 in Example 4;

[0020] Figure 6Schematic diagram of the functional relationship between R (Ni atomic ratio / Fe atomic ratio) and S (Ni target sputtering power / Fe target sputtering power). DETAILED DESCRIPTION

[0021] Example 1

[0022] This embodiment includes the following steps:

[0023] Step 1: Clean the substrate with acetone, anhydrous ethanol, and deionized water in sequence, and blow dry with an N2 air gun; the substrate is a 500 nm thick Si(100) substrate.

[0024] Step 2: Using the magnetron sputtering coating process, the Ni target and the Fe target are co-sputtered to deposit a NiFe film on the substrate surface; the magnetron sputtering conditions are: sputtering temperature of 20 °C, working gas of Ar gas, working pressure of 5 mTorr, background vacuum of 5×10 -5 Pa, sputtering time is 15min, target-substrate distance is 120mm, sample stage speed is 10rpm; Ni target adopts DC sputtering, Fe target adopts DC sputtering; Ni target power is 20W, Fe target power is 20W.

[0025] Step 3: Perform EDS test on the NiFe film obtained in step 2:

[0026] Through EDS testing, the Ni content in step 2 was obtained to be 0.686, and the Fe content was 0.314, so the nickel-iron atomic ratio was 0.686:0.314≈2.185:1.

[0027] From the data of Example 1, it can be seen that R (Ni atomic ratio / Fe atomic ratio)=2.185, and S (Ni target sputtering power / Fe target sputtering power)=20 / 20=1.

[0028] Example 2

[0029] The difference between this embodiment and embodiment 1 lies in step 2. In this embodiment, the sputtering power P of the Ni target is 15W, and the sputtering power of the Fe target is fixed at 20W.

[0030] EDS test: Ni content is 0.624, Fe content is 0.376, and the nickel-iron atomic ratio is 0.624 / 0.376=1.660.

[0031] From the data of Example 2, it can be seen that R (Ni atomic ratio / Fe atomic ratio) = 1.660, and S (Ni target sputtering power / Fe target sputtering power) = 15 / 20 = 0.75.

[0032] Example 3

[0033] The difference between this embodiment and embodiment 1 lies in step 2. In this embodiment, the sputtering power P of the Ni target is 40W, and the sputtering power of the Fe target is fixed at 20W.

[0034] EDS test: Ni content is 0.813, Fe content is 0.187, and the nickel-iron atomic ratio is 0.813 / 0.187=4.348;

[0035] From the data of Example 3, it can be seen that R (Ni atomic ratio / Fe atomic ratio) = 4.348, and S (Ni target sputtering power / Fe target sputtering power) = 40 / 20 = 2.

[0036] Example 4

[0037] The difference between this embodiment and embodiment 1 lies in step 2. In this embodiment, the sputtering power P of the Ni target is 70W, and the sputtering power of the Fe target is fixed at 20W.

[0038] EDS test: Ni content is 0.896, Fe content is 0.104, and the nickel-iron atomic ratio is 0.896 / 0.104=8.615;

[0039] From the data of Example 4, it can be seen that R (Ni atomic ratio / Fe atomic ratio) = 8.615, S (Ni target sputtering power / Fe target sputtering power) = 70 / 20 = 3.5.

[0040] Example 5

[0041] The difference between this embodiment and embodiment 1 lies in step 2. In this embodiment, the sputtering power P of the Ni target is 95W, and the sputtering power of the Fe target is fixed at 20W.

[0042] EDS test: Ni content is 0.919, Fe content is 0.081, and the nickel-iron atomic ratio is 0.919 / 0.081=11.346;

[0043] From the data of Example 5, it can be seen that R (Ni atomic ratio / Fe atomic ratio) = 11.346, and S (Ni target sputtering power / Fe target sputtering power) = 4.75.

[0044] The data of each embodiment are as follows Figure 6 As shown, it can be seen that they all obey the following distribution:

[0045] R = a × (2.471 × S - 0.3), where 0.94 <a<1.07。

[0046] In summary, the present invention addresses the problem of the prior art in being unable to accurately determine the nickel-iron content ratio in nickel-iron films. The present invention utilizes simple and convenient EDS test results and calculation formulas to predict the composition of nickel-iron films. The sputtering power can also be adjusted based on the desired composition of the desired nickel-iron film, with an error rate of less than 2% for the composition content of the film. This invention enables a method for achieving adjustable nickel-iron binary alloy film formulations, significantly reducing experimental time and costs while ensuring high accuracy.

Claims

1. A method for preparing a nickel-iron thin film, comprising the following steps: Step 1: Cleaning the Si(100) substrate, Ni target and Fe target; Step 2: Using an ultra-high vacuum magnetron sputtering coating process, Fe target and Ni target are co-sputtered to deposit a NiFe film on the substrate surface; It is characterized in that In the step 2, both the Ni target and the Fe target are sputtered by DC, and the material ratio of the NiFe film is controlled by the following formula: R = a × (2.471 × S - 0.3), where 0.94 <a<1.07 Among them, R=Ni atomic ratio / Fe atomic ratio, S=Ni target sputtering power / Fe target sputtering power, and the sputtering powers of Ni target and Fe target are both in the range of 10W to 200W.

2. The method for preparing nickel-iron film according to claim 1, wherein In the step 2, the magnetron sputtering conditions are as follows: the sputtering temperature is 18-25°C, the working gas is Ar gas, the working pressure is 3-7 mTorr, and the background vacuum is 3×10 -5 Pa~7×10 -5 Pa.

3. The method for preparing nickel-iron film according to claim 1, wherein The step 1 is: using acetone, anhydrous ethanol and deionized water to clean the substrate in sequence, and blowing it dry with an N2 air gun; the substrate is a Si (100) substrate with a thickness of 500 nm.

4. The method for preparing nickel-iron film according to claim 1, wherein In the step 2, the sputtering time is 15 min, the target-substrate distance is 120 mm, and the sample stage rotation speed is 10 rpm.

5. The method for preparing nickel-iron film according to claim 1, wherein In step 2, the magnetron sputtering conditions are as follows: sputtering temperature is 20°C, working gas is Ar gas, working pressure is 5 mTorr, background vacuum is 5×10 -5 Pa.

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